Template-Type: ReDIF-Article 1.0
Author-Name: D. J. Murray_smith
Author-X-Name-First: D. J.
Author-X-Name-Last: Murray_smith
Title: Methods for the external validation of contiuous system simulation models:a review
Abstract:
External validation is an integral part of the process of
simulation model development. Many methods of external validation of
continuous system simulation models have been proposed and, inevitably,
the approach selected in any given application is highly dependent upon
the purpose of the model and the associated accuracy requirements.
Although the process of external validation has subjective aspects,
formalisation of methods in some safety-critical fields of application has
provided a basis for the development of objective measures of model
performance. Such measures can be applied in other application areas and
allow the whole process of assessing model credibility to be put on a
firmer foundation. This paper reviews available methods, discusses
practical issues that can arise in the application of these validation
techniques and gives a brief account of some validation problems in
selected application areas.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 5-31
Issue: 1
Volume: 4
Year: 1998
Month: 1
X-DOI: 10.1080/13873959808837066
File-URL: http://hdl.handle.net/10.1080/13873959808837066
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:4:y:1998:i:1:p:5-31
Template-Type: ReDIF-Article 1.0
Author-Name: Gary J. Gray
Author-X-Name-First: Gary J.
Author-X-Name-Last: Gray
Title: An investigation of open-loop and inverse simulation as nonlinear model validation tools for helicopter flight mechanics
Abstract:
The nonlinear model validation techniques of open-loop and
inverse simulation are introduced. The methodologies are explained and
examples are given. The paper presents the results of an investigation
into the use of open-loop and inverse simulation to help in the
development of a nonlinear real-time helicopter model. The individual
rigid body state equations in the model are simulated with the aim of
producing insight into the cause of inaccuracies in the model. A suspected
source of inaccuracy is verified using partial open-loop simulation.
Unmodelled dynamics are represented by using the relevant flight data as
an open-loop input to the simulation thus revealing the effect of
incorporating those dynamics. After localising the cause of inaccuracies
in the simulation model, modifications and improvements are verified using
closed-loop simulation. The improvements are then evaluated by comparing
results in normal and inverse simulation modes.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 32-57
Issue: 1
Volume: 4
Year: 1998
Month: 1
X-DOI: 10.1080/13873959808837067
File-URL: http://hdl.handle.net/10.1080/13873959808837067
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:4:y:1998:i:1:p:32-57
Template-Type: ReDIF-Article 1.0
Author-Name: Rob Cameron
Author-X-Name-First: Rob
Author-X-Name-Last: Cameron
Author-Name: Rafael Lopez marcos
Author-X-Name-First: Rafael
Author-X-Name-Last: Lopez marcos
Author-Name: Cesar Deprada
Author-X-Name-First: Cesar
Author-X-Name-Last: Deprada
Title: Model validation of discrete transfer functions using the distortion method
Abstract:
The distortion method, developed by Butterfield and
colleagues for non-linear systems, is developed for the case of single-
and multiple-input linear transfer functions. The assumption of linearity
allows expressions for the distortions to be developed analytically, thus
significantly reducing the computational cost of the original technique.
In the context of transfer function models, the method provides a tool for
comparing the performance of one model with another, for example a
linearised model of a non-linear system of equations, or of a reduced
order model of a high order model
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 58-72
Issue: 1
Volume: 4
Year: 1998
Month: 1
X-DOI: 10.1080/13873959808837068
File-URL: http://hdl.handle.net/10.1080/13873959808837068
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:4:y:1998:i:1:p:58-72
Template-Type: ReDIF-Article 1.0
Author-Name: E. R. Carson
Author-X-Name-First: E. R.
Author-X-Name-Last: Carson
Author-Name: R. Hovorka
Author-X-Name-First: R.
Author-X-Name-Last: Hovorka
Author-Name: A. V. Roudsari
Author-X-Name-First: A. V.
Author-X-Name-Last: Roudsari
Author-Name: R. Summers
Author-X-Name-First: R.
Author-X-Name-Last: Summers
Title: Modelling and decision support in physiology and medicine: a methodological framework with lllustration
Abstract:
This paper presents a methodological framework for modelling
that has found wide application in the complex domains of physiology and
medicine. The processes of model validation are centrally embedded within
this framework. The parallelism between modelling per se and the
development of model-based decision support systems is then considered,
showing that it is possible to devise a unified methodological framework
which encompasses the requirements both of model validation and decision
support system evaluation. The applicability of the framework is
demonstrated in the validation of a mathematical model of blood glucose
dynamics; and in the development and evaluation of decision support
systems such as those which are aimed at addressing the problem of
advising the insulin-dependent diabetic patient on the adjustment of
insulin dosage
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 73-99
Issue: 1
Volume: 4
Year: 1998
Month: 1
X-DOI: 10.1080/13873959808837069
File-URL: http://hdl.handle.net/10.1080/13873959808837069
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Handle: RePEc:taf:nmcmxx:v:4:y:1998:i:1:p:73-99
Template-Type: ReDIF-Article 1.0
Author-Name: Gong Mingrui
Author-X-Name-First: Gong
Author-X-Name-Last: Mingrui
Author-Name: D. J. Murray-Smith
Author-X-Name-First: D. J.
Author-X-Name-Last: Murray-Smith
Title: A practical exercise in simulation model validation
Abstract:
The validation of continuous system simulation models is a
matter of great practical importance. Unfortunately, however, it often
receives very little attention in university-level courses on modelling
and simulation. The paper considers some possible reasons for the lack of
emphasis given to model validation issues in education and describes an
exercise which has been designed to introduce students to some practical
aspects of internal verification and external validation of nonlinear
dynamic models. The work involves a laboratory-scale system based on two
inter-connected tanks of liquid and also demonstrates some important
limitations of a widely-used nonlinear model. Features which make the
chosen system particularly suitable for this teaching application include
the relatively simple physical nature of the system and the fact that all
the key variables of the model are accessible for measurement. Students
are exposed to a range of practical issues, such as the selection of the
sampling rate for data collection and the design of experiments to provide
data sets appropriate for external validation purposes. Dealing
successfully with such questions and carrying out validation tests exposes
students to concepts of model credibility and the whole process of model
development and application. They are also challenged in terms of their
practical abilities to use computer simulation techniques and in their
understanding of the mathematical model and the physics of the real
system. It is argued that an exercise of this type can have very important
educational benefits.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 100-117
Issue: 1
Volume: 4
Year: 1998
Month: 1
X-DOI: 10.1080/13873959808837070
File-URL: http://hdl.handle.net/10.1080/13873959808837070
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Handle: RePEc:taf:nmcmxx:v:4:y:1998:i:1:p:100-117
Template-Type: ReDIF-Article 1.0
Author-Name: C. Maffezzoni
Author-X-Name-First: C.
Author-X-Name-Last: Maffezzoni
Author-Name: R. Girelli
Author-X-Name-First: R.
Author-X-Name-Last: Girelli
Title: Moses: modular modelling of physical systems in an object-oriented database
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 121-147
Issue: 2
Volume: 4
Year: 1998
Month: 1
X-DOI: 10.1080/13873959808837073
File-URL: http://hdl.handle.net/10.1080/13873959808837073
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Handle: RePEc:taf:nmcmxx:v:4:y:1998:i:2:p:121-147
Template-Type: ReDIF-Article 1.0
Author-Name: Sriram srinivasan
Author-X-Name-First: Sriram
Author-X-Name-Last: srinivasan
Author-Name: Rajesh Rajamani
Author-X-Name-First: Rajesh
Author-X-Name-Last: Rajamani
Title: Analytical modelling of the structural acoustic vibrations in a paneled box
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 148-161
Issue: 2
Volume: 4
Year: 1998
Month: 1
X-DOI: 10.1080/13873959808837074
File-URL: http://hdl.handle.net/10.1080/13873959808837074
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:4:y:1998:i:2:p:148-161
Template-Type: ReDIF-Article 1.0
Author-Name: M. Arnold
Author-X-Name-First: M.
Author-X-Name-Last: Arnold
Author-Name: H. Netter
Author-X-Name-First: H.
Author-X-Name-Last: Netter
Title: Apporoximation of contact geometry in the dynamical simulation of wheel-rail
Abstract:
Models for the geometrical contact of wheel and rail are a
basic component of multibody system (MBS) models for wheel-rail systems.
Approximations are used to get sufficiently differentiable contact
conditions that can be evaluated efficiently. We discuss an approximation
that is essentially based on polynomial 2D-tensorproduct splines and
minimizes a functional that combines a weighted least squares
approximation of a rigid contact model with a smoothing term. An efficient
algorithm to compute the tensorproduct spline is developed, the
parallelization on a cluster of workstations is discussed. We report on
results of both the sequential and the parallel algorithm and give
simulation results for a rigid wheelset on a straight track.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 162-184
Issue: 2
Volume: 4
Year: 1998
Month: 1
X-DOI: 10.1080/13873959808837075
File-URL: http://hdl.handle.net/10.1080/13873959808837075
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Handle: RePEc:taf:nmcmxx:v:4:y:1998:i:2:p:162-184
Template-Type: ReDIF-Article 1.0
Author-Name: S. O. Wasbø
Author-X-Name-First: S. O.
Author-X-Name-Last: Wasbø
Author-Name: B. A. Foss
Author-X-Name-First: B. A.
Author-X-Name-Last: Foss
Title: Modelling unit processes using formal language description and object-orientation
Abstract:
In this article we demonstrate how object-orientation and
formal languages can be applied in modelling unit processes. We suggest a
model representation where unit processes are decomposed into a two-level
hierarchy based on a set of elementary building blocks. The formal
language description is used as an alternative representation of the
model. Wcshow how it can be used for checking model consistency and as a
basis to derive model equations. The possible use of the concept in a
model assistant is discussed
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 185-206
Issue: 3
Volume: 4
Year: 1998
Month: 1
X-DOI: 10.1080/13873959808837077
File-URL: http://hdl.handle.net/10.1080/13873959808837077
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Handle: RePEc:taf:nmcmxx:v:4:y:1998:i:3:p:185-206
Template-Type: ReDIF-Article 1.0
Author-Name: B. Nilsson
Author-X-Name-First: B.
Author-X-Name-Last: Nilsson
Author-Name: J. Eborn
Author-X-Name-First: J.
Author-X-Name-Last: Eborn
Title: Object-oriented modelling of thermal power plants
Abstract:
This paper presents a set of model libraries, called K2, for
modelling of thermal power plants. The models are based on first
principles and describe mainly the dynamic mass and energy properties of
the modelled system. The K2 models are described in the object-oriented
modelling language OMOLA and the libraries are organized in an OMOLA model
database. The libraries are grouped into three different sets, namely unit
libraries, subunit libraries and model component libraries. The unit
models are used to build up plant system models, which are application
dependent. The units are composed of subunits. The subunits describe
different physical phenomena and a set of subunits build up the behaviour
of the unit model. Model components are used to facilitate the development
of new units and subunits. OMOLA models can be simulated in the OMSIM
simulation environment and the K2 model database has been used in a case
study of the dynamics in an HRSG plant.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 207-218
Issue: 3
Volume: 4
Year: 1998
Month: 1
X-DOI: 10.1080/13873959808837078
File-URL: http://hdl.handle.net/10.1080/13873959808837078
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Handle: RePEc:taf:nmcmxx:v:4:y:1998:i:3:p:207-218
Template-Type: ReDIF-Article 1.0
Author-Name: T. Senjyu
Author-X-Name-First: T.
Author-X-Name-Last: Senjyu
Author-Name: N. Urasakt
Author-X-Name-First: N.
Author-X-Name-Last: Urasakt
Author-Name: T. Simabukuro
Author-X-Name-First: T.
Author-X-Name-Last: Simabukuro
Author-Name: K. Uezato
Author-X-Name-First: K.
Author-X-Name-Last: Uezato
Title: Modelling and parameter measurement of salient-pole permanent magnet synchronous motors including stator iron loss
Abstract:
This paper presents a voltage equation and a parameter
measurement for salient-pole permanent magnet synchronous motors including
the stator iron loss. The stator iron loss is modelled by additional
windings on the dq axes, and is introduced as an equivalent iron loss
resistance in voltage equations under the assumption that the losses in
the stator core are produced in equivalent eddy current windings on the dq
axes. The voltage equation including the equivalent iron loss resistance
of the stator is derived with time constant approximations of equivalent
eddy current circuits. Machine parameters in the voltage equation are
measured by both the single-phase test and the generating test.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 219-230
Issue: 3
Volume: 4
Year: 1998
Month: 1
X-DOI: 10.1080/13873959808837079
File-URL: http://hdl.handle.net/10.1080/13873959808837079
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:4:y:1998:i:3:p:219-230
Template-Type: ReDIF-Article 1.0
Author-Name: Upset Robert
Author-X-Name-First: Upset
Author-X-Name-Last: Robert
Author-Name: P.Van Til Robert
Author-X-Name-First: P.Van Til
Author-X-Name-Last: Robert
Author-Name: Sengupta Sankar
Author-X-Name-First: Sengupta
Author-X-Name-Last: Sankar
Title: Development of a model for a two-station serial transfer line subject to machine and buffer failure
Abstract:
In modern automated production lines, it is common to connect
pairs of machines with mechanical storage devices in order to provide
buffering between processing stations. Since these devices are mechanical,
they are prone to failure. Previous research concerning the analytical
modeling of a class of production lines, the serial transfer line, assumes
that these buffers are completely reliable. The concept of an unreliable
buffer is introduced and an analytic model of a two machine line with an
unreliable buffer is developed. It is proposed that this model will form
the foundation for an analytic model of the more complex K > 2 machine
serial transfer line with unreliable buffers.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 231-246
Issue: 3
Volume: 4
Year: 1998
Month: 1
X-DOI: 10.1080/13873959808837080
File-URL: http://hdl.handle.net/10.1080/13873959808837080
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:4:y:1998:i:3:p:231-246
Template-Type: ReDIF-Article 1.0
Author-Name: A. Varga
Author-X-Name-First: A.
Author-X-Name-Last: Varga
Author-Name: G. Looye
Author-X-Name-First: G.
Author-X-Name-Last: Looye
Author-Name: D. Moormann
Author-X-Name-First: D.
Author-X-Name-Last: Moormann
Author-Name: G. Gräbel
Author-X-Name-First: G.
Author-X-Name-Last: Gräbel
Title: Automated generation of LFT-based parametric uncertainty descriptions from generic aircraft models
Abstract:
A computer assisted modelling methodology is developed for
the generation of linearized models with parametric uncertainties
described by Linear Fractional Transformations (LFTs). The starting point
of the uncertainty modelling is a class of generic nonlinear aircraft
models with explicit parametric dependence used for simulation purposes.
The proposed methodology integrates specialized software tools for
object-oriented modelling, for simulation, and for numerical as well as
symbolic computations. The methodology has many generic features being
applicable to similar nonlinear model classes.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 249-274
Issue: 4
Volume: 4
Year: 1998
Month: 1
X-DOI: 10.1080/13873959808837082
File-URL: http://hdl.handle.net/10.1080/13873959808837082
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Handle: RePEc:taf:nmcmxx:v:4:y:1998:i:4:p:249-274
Template-Type: ReDIF-Article 1.0
Author-Name: J. -A. Müller
Author-X-Name-First: J. -A.
Author-X-Name-Last: Müller
Author-Name: A. G. Ivachnenko
Author-X-Name-First: A. G.
Author-X-Name-Last: Ivachnenko
Author-Name: F. Lemke
Author-X-Name-First: F.
Author-X-Name-Last: Lemke
Title: GMDH algorithms for complex systems modelling
Abstract:
At present, GMDH algorithms give us a way to identify and
forecast economic processes in the case of noised and short input
sampling. In contrast to neural networks, the results are explicit
mathematical models, obtained in a relatively short time. For ill-defined
objects with very big noises, better results are obtained by analog
complexing methods. Nets with active neurons should be applied to increase
accuracy. Active neurons are able, during the self-organizing process, to
estimate which inputs are necessary to minimize the given objective
function of the neuron. In the neuronet with such neurons, we have a
twofold multilayered structure: neurons themselves are multilayered, and
they will be united into a multilayered network.
SelfOrganize! is an easy-to-use modelling tool which realizes
twice-multilayered neu-ronets and enables the creation of time series,
single input/single output, multi-input/single output and
multi-input/multi-output systems (system of equations). Successful
applications are shown in the field of analysis and prediction of
characteristics of stock markets in financial risk control modelling.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 275-316
Issue: 4
Volume: 4
Year: 1998
Month: 1
X-DOI: 10.1080/13873959808837083
File-URL: http://hdl.handle.net/10.1080/13873959808837083
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Handle: RePEc:taf:nmcmxx:v:4:y:1998:i:4:p:275-316
Template-Type: ReDIF-Article 1.0
Author-Name: S.L. Campbell
Author-X-Name-First: S.L.
Author-X-Name-Last: Campbell
Author-Name: W. Marszalek
Author-X-Name-First: W.
Author-X-Name-Last: Marszalek
Title: The Index of an Infinite Dimensional Implicit System
Abstract:
The idea of the index of a differential algebraic equation
(DAE) (or implicit differential equation) has played a fundamental role in
both the analysis of DAEs and the development of numerical algorithms for
DAEs. DAEs frequently arise as partial discretizations of partial
differential equations (PDEs). In order to relate properties of the PDE to
those of the resulting DAE it is necessary to have a concept of the index
of a possibly constrained PDE. Using the finite dimensional theory as
motivation, this paper will examine what one appropriate analogue is for
infinite dimensional systems. A general definition approach will be given
motivated by the desire to consider numerical methods. Specific examples
illustrating several kinds of behavior will be considered in some detail.
It is seen that our definition differs from purely algebraic definitions.
Numerical solutions, and simulation difficulties, can be misinterpreted if
this index information is missing.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 18-42
Issue: 1
Volume: 5
Year: 1999
Month: 3
X-DOI: 10.1076/mcmd.5.1.18.3625
File-URL: http://hdl.handle.net/10.1076/mcmd.5.1.18.3625
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Handle: RePEc:taf:nmcmxx:v:5:y:1999:i:1:p:18-42
Template-Type: ReDIF-Article 1.0
Author-Name: A. Bonsignore
Author-X-Name-First: A.
Author-X-Name-Last: Bonsignore
Author-Name: G. Ferretti
Author-X-Name-First: G.
Author-X-Name-Last: Ferretti
Author-Name: G. Magnani
Author-X-Name-First: G.
Author-X-Name-Last: Magnani
Title: Analytical Formulation of the Classical Friction Model for Motion Analysis and Simulation
Abstract:
Starting from a precise definition of friction torque when
velocity vanishes that distinguishes the case of instantaneous zero
crossing from that where the velocity is zero over a time interval, this
paper proposes a compact analytical formulation of the classical
discontinuous friction model that is useful for motion analysis. A finite
state machine that allows a numerically robust computation of motion
equations when velocity vanishes or motion restarts is then defined.
Simulation results show that the discontinuous model can be seen as an
asymptotic approximation, infinitely fast, of a recently proposed
continuous, dynamic friction model.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 43-54
Issue: 1
Volume: 5
Year: 1999
Month: 3
X-DOI: 10.1076/mcmd.5.1.43.3624
File-URL: http://hdl.handle.net/10.1076/mcmd.5.1.43.3624
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:5:y:1999:i:1:p:43-54
Template-Type: ReDIF-Article 1.0
Author-Name: W.D. Lakin
Author-X-Name-First: W.D.
Author-X-Name-Last: Lakin
Author-Name: J. Yu
Author-X-Name-First: J.
Author-X-Name-Last: Yu
Author-Name: P.L. Penar
Author-X-Name-First: P.L.
Author-X-Name-Last: Penar
Title: Analysis and Validation of a Mathematical Model for Intracranial Pressure Dynamics
Abstract:
Lumped parameter, compartmental models provide a promising
Method for mathematically studying the dynamics of human intracranial
pressure. In this modeling approach, a system of fully time-dependent
differential equations for interacting compartmental pressures is obtained
by considering the intracranial system to be confined within the
almost-rigid skull and developing continuity equations associated with
conservation of mass. Intracranial volumes and flows are related to
compartmental pressure differences through compliance and resistance
parameters. In the nonlinear case where compliances are not constant,
there is a lack of physical information about these parameters.
Consequently, it is vital that any mathematical model with an assumed
pressure-dependent compliance be validated through comparison with
experimental data. The present work develops a logistic representation for
the compliance between the cerebrospinal fluid and brain matter
compartments. The nonlinear mathematical model involving this logistic
compliance is validated here by comparing its predicted response for bolus
injections of cerebrospinal fluid to laboratory data generated in an
animal model. Comparison with the animal studies fully supports the
validity of the mathematical model with the logistic compliance.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 55-73
Issue: 1
Volume: 5
Year: 1999
Month: 3
X-DOI: 10.1076/mcmd.5.1.55.3623
File-URL: http://hdl.handle.net/10.1076/mcmd.5.1.55.3623
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:5:y:1999:i:1:p:55-73
Template-Type: ReDIF-Article 1.0
Author-Name: C.D. Johnson
Author-X-Name-First: C.D.
Author-X-Name-Last: Johnson
Title: On the Complete "Discretization" of an nth -Order Linear Differential Equation Model to Obtain the Exact nth-Order Difference Equation Model with Correct "Initial-Sequence Values"
Abstract:
The conversion of a given n th -order ordinary
differential-equation model, with a stepwise-constant input, to an
"equivalent" n th -order difference -equation model is an important
procedure in many engineering applications, particularly in
discrete-time/digital control theory for linear dynamical systems. That
procedure, called "discretization", is not complete unless the given
initial-conditions of the differential-equation model are properly
incorporated into the corresponding "initial-sequence values" associated
with the difference-equation model. The literature of
discrete-time/digital control theory appears to be consistently incomplete
in this latter regard. In this paper we derive the complete and exact
discretization of an arbitrary n th -order linear, constant-coefficient,
non-homogeneous ordinary differential equation model, with arbitrary
initial-conditions and a stepwise-constant input, to obtain the
corresponding exact equivalent n th -order, linear, constant-coefficient,
non- difference equation model with correct initial-sequence values.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 74-84
Issue: 1
Volume: 5
Year: 1999
Month: 3
X-DOI: 10.1076/mcmd.5.1.74.3622
File-URL: http://hdl.handle.net/10.1076/mcmd.5.1.74.3622
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Handle: RePEc:taf:nmcmxx:v:5:y:1999:i:1:p:74-84
Template-Type: ReDIF-Article 1.0
Author-Name: M. Delgado
Author-X-Name-First: M.
Author-X-Name-Last: Delgado
Author-Name: G. Profos
Author-X-Name-First: G.
Author-X-Name-Last: Profos
Title: Identifiability of Dynamic Systems Represented by Bond Graphs
Abstract:
In this paper, the identifiability of dynamical systems is
presented from the perspective of the Bond Graph Methodology. Several
classical approaches for identifiability are studied and their
applicability to bond graphs is discussed. The Markov Parameter method was
selected to determine local identifiability of linear systems and a
methodical procedure to obtain Markov Parameters directly from the bond
graph is presented which is based on its causal paths. This method can
easily be implemented in on a computer and works for bond graphs with
derivative causality elements and fields.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 89-112
Issue: 2
Volume: 5
Year: 1999
Month: 6
X-DOI: 10.1076/mcmd.5.2.89.6174
File-URL: http://hdl.handle.net/10.1076/mcmd.5.2.89.6174
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Handle: RePEc:taf:nmcmxx:v:5:y:1999:i:2:p:89-112
Template-Type: ReDIF-Article 1.0
Author-Name: Michael Tittus
Author-X-Name-First: Michael
Author-X-Name-Last: Tittus
Author-Name: Knut Åkesson
Author-X-Name-First: Knut
Author-X-Name-Last: Åkesson
Title: Petri Net Models in Batch Control
Abstract:
A Petri-net based approach for the modeling of batch plants
as well as products is presented. The different units of a plant are
modeled as bounded Petri nets and products are represented by way of their
recipes.With the focus on synchronization and booking issues arising when
merging and splitting material flows, we propose general Petri net
building-blocks for the construction of these recipes. Both resource and
recipe models support formal supervisor synthesis for dynamic resource
allocation according to the Ramadge-Wonham framework.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 113-132
Issue: 2
Volume: 5
Year: 1999
Month: 6
X-DOI: 10.1076/mcmd.5.2.113.6173
File-URL: http://hdl.handle.net/10.1076/mcmd.5.2.113.6173
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Handle: RePEc:taf:nmcmxx:v:5:y:1999:i:2:p:113-132
Template-Type: ReDIF-Article 1.0
Author-Name: R. Korb
Author-X-Name-First: R.
Author-X-Name-Last: Korb
Author-Name: H.P. Jörgl
Author-X-Name-First: H.P.
Author-X-Name-Last: Jörgl
Author-Name: B. Lutz
Author-X-Name-First: B.
Author-X-Name-Last: Lutz
Title: Nonlinear Dynamic Modelling of a Gas Engine Using an RBF-Network
Abstract:
A Radial Basis Function network (RBFN) is used to obtain a
model of a gas engine, an unstable two-input/single-output system
(MISO-system), to be used for the design of the speed control system. The
RBFN-centers are chosen using the stepwise orthogonalization algorithm,
and an input space compression which helps to avoid sparse data sets is
presented. The influence of noisy data is investigated in a nonlinear
system example, in order to find the cause of the model errors in the case
of the gas engine model. The quality of the nonlinear RBFN-model is
demonstrated by comparing measured and simulated data.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 133-151
Issue: 2
Volume: 5
Year: 1999
Month: 6
X-DOI: 10.1076/mcmd.5.2.133.6171
File-URL: http://hdl.handle.net/10.1076/mcmd.5.2.133.6171
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Handle: RePEc:taf:nmcmxx:v:5:y:1999:i:2:p:133-151
Template-Type: ReDIF-Article 1.0
Author-Name: A. Ilchmann
Author-X-Name-First: A.
Author-X-Name-Last: Ilchmann
Author-Name: A. Ilchmann
Author-X-Name-First: A.
Author-X-Name-Last: Ilchmann
Title: Modelling of General Biotechnological Processes
Abstract:
A general biotechnological process is modelled by a finite
dimensional ordinary differential equation. The stoichiometry is only
modelled qualitatively. It is shown that the usual biochemically motivated
assumptions are not sufficient to guarantee boundedness of the solution.
To overcome this, the concept of non-cyclic biotechnological processes is
introduced. Loosely speaking it means that the process does not contain
any “reaction loop”. The assumption of non-cyclicity
replaces the common assumption of Conservation of Mass. An algorithm is
presented so that after finitely many steps it is decided whether a
process is non-cyclic or cyclic. Non-cyclicity is also characterised in
terms of an echelon matrix derived from the stoichiometric matrix via
permutations of columns and rows.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 152-178
Issue: 2
Volume: 5
Year: 1999
Month: 6
X-DOI: 10.1076/mcmd.5.2.152.6172
File-URL: http://hdl.handle.net/10.1076/mcmd.5.2.152.6172
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Handle: RePEc:taf:nmcmxx:v:5:y:1999:i:2:p:152-178
Template-Type: ReDIF-Article 1.0
Author-Name: M. Oberguggenberger
Author-X-Name-First: M.
Author-X-Name-Last: Oberguggenberger
Author-Name: S. Pittschmann
Author-X-Name-First: S.
Author-X-Name-Last: Pittschmann
Title: Differential Equations With Fuzzy Parameters
Abstract:
This paper is concerned with systems of ordinary differential
equations with fuzzy parameters. Applying the Zadeh extension principle to
the equations, we introduce the notions of fuzzy solutions and of
componentwise fuzzy solutions. The fuzzy extension of the solution
operator is shown to provide the unique fuzzy solution as well as the
maximal componentwise fuzzy solution. A numerical algorithm based on
monotonicity properties of membership functions is presented, together
with a proof of convergence. In an interplay of interval analysis and
possibility theory, these methods allow to process subjective information
on the possible fluctuations of parameters in models involving ordinary
differential equations. This is demonstrated in two engineering
applications: a queueing model for earthwork and a model of oscillations
of bell-towers.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 181-202
Issue: 3
Volume: 5
Year: 1999
Month: 9
X-DOI: 10.1076/mcmd.5.3.181.3683
File-URL: http://hdl.handle.net/10.1076/mcmd.5.3.181.3683
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Handle: RePEc:taf:nmcmxx:v:5:y:1999:i:3:p:181-202
Template-Type: ReDIF-Article 1.0
Author-Name: V. Gontar
Author-X-Name-First: V.
Author-X-Name-Last: Gontar
Author-Name: M. Gutman
Author-X-Name-First: M.
Author-X-Name-Last: Gutman
Title: Method for Computer Simulation of Chaotic and Complex Periodic Oscillations
Abstract:
The possibility of constructing chaotic and complex periodic
orbits of desired configurations is demonstrated on one-dimensional
discontinuous maps. With appropriately located discontinuity, these maps
can generate a rich selection of specific orbits with long laminar
segments. A simple method is proposed to determine the features of the
orbit obtained. This technique, applied to special maps with a horizontal
linear branch, allows us to generate a great variety of stable periodic
orbits with a specified future by only small variations of the map control
parameter.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 203-219
Issue: 3
Volume: 5
Year: 1999
Month: 9
X-DOI: 10.1076/mcmd.5.3.203.3682
File-URL: http://hdl.handle.net/10.1076/mcmd.5.3.203.3682
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Handle: RePEc:taf:nmcmxx:v:5:y:1999:i:3:p:203-219
Template-Type: ReDIF-Article 1.0
Author-Name: G.C. Goodwin
Author-X-Name-First: G.C.
Author-X-Name-Last: Goodwin
Author-Name: A. Feuer
Author-X-Name-First: A.
Author-X-Name-Last: Feuer
Title: Estimation with Missing Data
Abstract:
This paper reviews estimation problems with missing, or
hidden data. We formulate this problem in the context of Markov models and
consider two interrelated issues, namely, the estimation of a state given
measured data and model parameters, and the estimation of model parameters
given the measured data alone. We also consider situations where the
measured data is, itself, incomplete in some sense. We deal with various
combinations of discrete and continuous states and observations.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 220-244
Issue: 3
Volume: 5
Year: 1999
Month: 9
X-DOI: 10.1076/mcmd.5.3.220.3681
File-URL: http://hdl.handle.net/10.1076/mcmd.5.3.220.3681
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Handle: RePEc:taf:nmcmxx:v:5:y:1999:i:3:p:220-244
Template-Type: ReDIF-Article 1.0
Author-Name: F.M. Borodich
Author-X-Name-First: F.M.
Author-X-Name-Last: Borodich
Title: Mathematical Models of Discrete Self-Similarity
Abstract:
Natural phenomena which exhibit discrete self-similarity are
under consideration. Earlier, self-similarity of some non-smooth phenomena
was studied using the concept of log-periodicity, however there was a gap
in this field. Recently it was attempted to fill this gap by concentrating
on the study of a new concept of parametric-homogeneity (PH) based on the
use of discrete group of coordinate dilations. It is argued that
parametric-homogeneity can be helpful in the modelling of self-similar
non-smooth phenomena. Some models of natural phenomena which have
PH-features are presented and some properties of PH-functions are
discussed. As an example of practical usage of these functions, the
phenomenon of seismic activation prior to a major earthquake is
considered.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 245-258
Issue: 3
Volume: 5
Year: 1999
Month: 9
X-DOI: 10.1076/mcmd.5.3.245.3680
File-URL: http://hdl.handle.net/10.1076/mcmd.5.3.245.3680
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Handle: RePEc:taf:nmcmxx:v:5:y:1999:i:3:p:245-258
Template-Type: ReDIF-Article 1.0
Author-Name: R. Rabenstein
Author-X-Name-First: R.
Author-X-Name-Last: Rabenstein
Title: Transfer Function Models for Multidimensional Systems with Bounded spatial Domains
Abstract:
Multidimensional (MD) systems describe relations between
signals depending on two or more independent variables. They are also
called distributed parameter systems, if the independent variables are
time and space. The only conventional models for their description are
partial differential equations. This is in contrast to onedimensional
(lumped parameter) systems, where a variety of different models including
transfer functions is used. This paper extends the concept of transfer
function models to multidimensional systems with bounded spatial domains,
i.e., systems which can be described as initial-boundary-value problems.
These transfer function models are useful for system analysis and as a
starting point for the derivation of numerically efficient discrete
simulation models.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 259-278
Issue: 3
Volume: 5
Year: 1999
Month: 9
X-DOI: 10.1076/mcmd.5.3.259.3679
File-URL: http://hdl.handle.net/10.1076/mcmd.5.3.259.3679
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Handle: RePEc:taf:nmcmxx:v:5:y:1999:i:3:p:259-278
Template-Type: ReDIF-Article 1.0
Author-Name: Jean-Pierre Barbary
Author-X-Name-First: Jean-Pierre
Author-X-Name-Last: Barbary
Author-Name: P. Lessard
Author-X-Name-First: P.
Author-X-Name-Last: Lessard
Title: Editorial
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 283-284
Issue: 4
Volume: 5
Year: 1999
Month: 12
X-DOI: 10.1076/mcmd.5.4.283.3677
File-URL: http://hdl.handle.net/10.1076/mcmd.5.4.283.3677
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Handle: RePEc:taf:nmcmxx:v:5:y:1999:i:4:p:283-284
Template-Type: ReDIF-Article 1.0
Author-Name: M. Köhne
Author-X-Name-First: M.
Author-X-Name-Last: Köhne
Author-Name: M. Shuhen
Author-X-Name-First: M.
Author-X-Name-Last: Shuhen
Author-Name: D. Schönberger
Author-X-Name-First: D.
Author-X-Name-Last: Schönberger
Title: Modelling and Simulation of Purification Processes in Wastewater Treatment Plants Using the Modular Toolbox KSIM
Abstract:
A short description of the modular toolbox KSIM for dynamic
simulation of purification processes in wastewater treatment plants is
given. The features and characteristics of KSIM, the information transfer
inside the simulation model, the design of the modules and the input of
the module parameters are discussed. An example is chosen to demonstrate
the use of KSIM for the development of control strategies optimizing the
wastewater treatment plant operation of nitrogen removal. Two different
control strategies for the operation of an equalizing basin at the
influent of the biological purification stage of a wastewater treatment
plant are compared and assessed by means of the simulation results.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 285-297
Issue: 4
Volume: 5
Year: 1999
Month: 12
X-DOI: 10.1076/mcmd.5.4.285.3676
File-URL: http://hdl.handle.net/10.1076/mcmd.5.4.285.3676
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Handle: RePEc:taf:nmcmxx:v:5:y:1999:i:4:p:285-297
Template-Type: ReDIF-Article 1.0
Author-Name: S. Kops
Author-X-Name-First: S.
Author-X-Name-Last: Kops
Author-Name: H. Vangheluwe
Author-X-Name-First: H.
Author-X-Name-Last: Vangheluwe
Author-Name: F. Claeys
Author-X-Name-First: F.
Author-X-Name-Last: Claeys
Author-Name: P. Vanrolleghem
Author-X-Name-First: P.
Author-X-Name-Last: Vanrolleghem
Author-Name: Z. Yuan
Author-X-Name-First: Z.
Author-X-Name-Last: Yuan
Author-Name: G. Vansteenkiste
Author-X-Name-First: G.
Author-X-Name-Last: Vansteenkiste
Title: The Process of Model Building and Simulation of Ill-Defined Systems: Application to Wastewater Treatment
Abstract:
In recent years, there has been a growing awareness of the
ill-defined nature of environmental processes. To provide a frame of
reference for discussions regarding ill-defined systems, a taxonomy and
terminology of the modelling and simulation of systems is presented. Due
to the complexity of ill-defined systems, it is not only necessary to
describe the nature of models, but also to describe modelling procedures.
This enables the modeller to obtain the model which best fits his goals
(optimal model). For meaningful description of models, different model
formalisms will be presented. Furthermore, modelling procedures will be
described at a generic level and different model formalisms will be
presented. Throughout this paper, Waste-Water Treatment Plants and
processes occurring within these plants will illustrate the definitions
given.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 298-312
Issue: 4
Volume: 5
Year: 1999
Month: 12
X-DOI: 10.1076/mcmd.5.4.298.3675
File-URL: http://hdl.handle.net/10.1076/mcmd.5.4.298.3675
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Handle: RePEc:taf:nmcmxx:v:5:y:1999:i:4:p:298-312
Template-Type: ReDIF-Article 1.0
Author-Name: Ján Derco
Author-X-Name-First: Ján
Author-X-Name-Last: Derco
Author-Name: Alexander Kovács
Author-X-Name-First: Alexander
Author-X-Name-Last: Kovács
Author-Name: Malin Králik
Author-X-Name-First: Malin
Author-X-Name-Last: Králik
Author-Name: Salima Shanshab
Author-X-Name-First: Salima
Author-X-Name-Last: Shanshab
Title: Modelling of an Intermittently Aerated Completely Mixed Activated Sludge Reactor
Abstract:
Mathematical models for description of dynamic behaviour of
simultaneous nitrification and denitrification processes carried out in an
intermittently aerated completely mixed activated sludge reactor (CMASR)
are presented. The general IAWPRC activated sludge model has been extended
with volatilisation process of wastewater impurity. The influence of
wastewater composition on oxygen transport rate is also included.
Different approaches for dissolved oxygen incorporation in biochemical
reaction kinetics have been applied. Determination of some biokinetic
parameter values by evaluating steady-state measurements of process
variables is implied in one version of the proposed models. Experimental
modelling of simultaneous nitrification and denitrification processes,
carried out in an industrial Carrousel activated sludge reactor, was
performed in the lab-scale intermittently aerated CMASR. Organic,
ammonium, and heavy metal shock loads were applied in order to simulate
transient behaviour of the lab-scale reactor and the influence of heavy
metal on biochemical processes and biokinetic parameter values has been
investigated. Dissolved oxygen concentration in activated sludge reactor,
COD, ammonium, nitrate and biomass concentration responses of reactor were
measured and evaluated. Good agreement between the observed data and
calculated values by verified models has been achieved. Estimated values
of biokinetic parameters, found by optimisation procedure, are close to
those recommended for simulation of domestic wastewater treatment
processes. The applicability of the IAWPRC kinetic and stoichiometric
concept for dynamic behaviour description of an intermittently aerated
CMASR reactor, including the above mentioned extension and modification,
is demonstrated in the work.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 313-336
Issue: 4
Volume: 5
Year: 1999
Month: 12
X-DOI: 10.1076/mcmd.5.4.313.3673
File-URL: http://hdl.handle.net/10.1076/mcmd.5.4.313.3673
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Handle: RePEc:taf:nmcmxx:v:5:y:1999:i:4:p:313-336
Template-Type: ReDIF-Article 1.0
Author-Name: S. Julien
Author-X-Name-First: S.
Author-X-Name-Last: Julien
Author-Name: P. Lessard
Author-X-Name-First: P.
Author-X-Name-Last: Lessard
Author-Name: J.P. Barbary
Author-X-Name-First: J.P.
Author-X-Name-Last: Barbary
Title: A Reduced Order Model for Control of a Single Reactor Activated Sludge Process
Abstract:
The IAWQ activated sludge model no 1, slightly modified by
adding a nitrogen limiting growth function for heterotrophic
microorganisms, has been validated on a sequencing single sludge
wastewater reactor doing nitrification and denitrification. However, this
model is too complex to be used for control design. The main purpose of
this paper is to show how it is possible to simplify the full model from
biological and mathematical considerations. Properties of observability,
controllability and theoretical identifiability have been analyzed. The
parameter identification has been carried out by using the simplex method
of Nelder & Mead. Simulation results performed over a range of six hours
(two aerobic / anoxic cycles), show that there exists a good fit between
the simulated solution and the actual behavior of a lab scale pilot plant.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 337-350
Issue: 4
Volume: 5
Year: 1999
Month: 12
X-DOI: 10.1076/mcmd.5.4.337.3672
File-URL: http://hdl.handle.net/10.1076/mcmd.5.4.337.3672
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Handle: RePEc:taf:nmcmxx:v:5:y:1999:i:4:p:337-350
Template-Type: ReDIF-Article 1.0
Author-Name: C. Hellinga
Author-X-Name-First: C.
Author-X-Name-Last: Hellinga
Author-Name: M.C.M. van Loosdrecht
Author-X-Name-First: M.C.M.
Author-X-Name-Last: van Loosdrecht
Author-Name: J.J. Heijnen
Author-X-Name-First: J.J.
Author-X-Name-Last: Heijnen
Title: Model Based Design of a Novel Process for Nitrogen Removal from Concentrated Flows
Abstract:
A new process for biological nitrification was developed that
is operated in a single aerated reactor at relatively high temperature and
pH. This process, termed SHARON, was designed to achieve substantial
ammonia conversion at high reaction rates for relatively concentrated
flows, rather than to meet strict effluent standards. First large scale
applications that are under construction now, aim at treating reject water
from a sludge digestion unit. The SHARON process operates without sludge
retention, and ammonium oxidation is stopped at nitrite, which saves on
aeration costs. Denitrification is used as a cheap means to control the
pH. Under typical conditions, no heating is necessary due to the heat
production by the reactions. Overall processing costs are less than 50% of
other techniques. This contribution focuses on model development for
process design calculations at full scale. Underlying kinetic principles,
and especially their pH dependency, are highlighted as well.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 351-371
Issue: 4
Volume: 5
Year: 1999
Month: 12
X-DOI: 10.1076/mcmd.5.4.351.3678
File-URL: http://hdl.handle.net/10.1076/mcmd.5.4.351.3678
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Handle: RePEc:taf:nmcmxx:v:5:y:1999:i:4:p:351-371
Template-Type: ReDIF-Article 1.0
Author-Name: J.F. Beteau
Author-X-Name-First: J.F.
Author-X-Name-Last: Beteau
Author-Name: T. Soehartanto
Author-X-Name-First: T.
Author-X-Name-Last: Soehartanto
Author-Name: F. Chaume
Author-X-Name-First: F.
Author-X-Name-Last: Chaume
Title: Model Based Selection of an Appropriate Control Strategy Application to an Anaerobic Digester
Abstract:
The aim of this work is to develop an integrated control of
anaerobic digesters in wastewater treatment plants, to ensure optimal
depollution performances. To achieve this goal, we have to summarise our
knowledge in a mathematical model, which is an essential tool for control
design. Various control strategies can be chosen, but their performances
are very different (stabilisation, biogaz production,...). Each of them is
evaluated through 3 criteria. Then we present an original linear model for
process stability which take into account the input pollution (flow rate,
concentration). We show with simulations how this model help us to select
the appropriate control strategy and the improvement of depollution
efficiency.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 372-389
Issue: 4
Volume: 5
Year: 1999
Month: 12
X-DOI: 10.1076/mcmd.5.4.372.3674
File-URL: http://hdl.handle.net/10.1076/mcmd.5.4.372.3674
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Handle: RePEc:taf:nmcmxx:v:5:y:1999:i:4:p:372-389
Template-Type: ReDIF-Article 1.0
Author-Name: Sebastian Engell
Author-X-Name-First: Sebastian
Author-X-Name-Last: Engell
Title: Introduction to the Special Issue on Discrete Event Models of Continuous Systems
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 3-5
Issue: 1
Volume: 6
Year: 2000
Month: 3
X-DOI: 10.1076/1387-3954(200003)6:1;1-Q;FT003
File-URL: http://hdl.handle.net/10.1076/1387-3954(200003)6:1;1-Q;FT003
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Handle: RePEc:taf:nmcmxx:v:6:y:2000:i:1:p:3-5
Template-Type: ReDIF-Article 1.0
Author-Name: J. Raisch
Author-X-Name-First: J.
Author-X-Name-Last: Raisch
Title: Discrete Abstractions of Continuous Systems -- an Input/Output Point of View
Abstract:
This contribution proposes a hierarchy of discrete ions for a
given continuous model. It adopts an input/output point of view, and
starts from the continuous system behaviour B
c (i.e.,
'the set of all pairs of input and output signals which are compatible
with the continuous model equations). The first step is to construct a
sequence of behaviours B
l , l =0, 1,..., such that
B 0 ⊇ B
1 ⊇... ⊇ B
c. In a second step, nondeterministic Moore automata
A_l are generated as minimal realizations for the behaviours
B
l . Hence, the continuous base
system and its discrete abstractions A l form a totally ordered set of
models, where ordering is in the sense of set inclusion of model
behaviours or, equivalently, in terms of approximation accuracy. Within
this set, there exists a uniquely defined “coarsest” (and
therefore least complex) model which allows a given set of specifications
to be enforced by discrete feedback. The ordering property implies that
this discrete feedback also forces the continuous base system to obey the
specifications.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 6-29
Issue: 1
Volume: 6
Year: 2000
Month: 3
X-DOI: 10.1076/1387-3954(200003)6:1;1-Q;FT006
File-URL: http://hdl.handle.net/10.1076/1387-3954(200003)6:1;1-Q;FT006
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Handle: RePEc:taf:nmcmxx:v:6:y:2000:i:1:p:6-29
Template-Type: ReDIF-Article 1.0
Author-Name: Alongkrit Chutinan
Author-X-Name-First: Alongkrit
Author-X-Name-Last: Chutinan
Author-Name: Bruce H. Krogh
Author-X-Name-First: Bruce H.
Author-X-Name-Last: Krogh
Title: Computing Approximating Automata for a Class of Hybrid Systems
Abstract:
This paper presents a new algorithm for generating
finite-state automata models of hybrid systems in which the
continuous-state dynamics can be switched when the continuous-state
trajectory generates threshold events. The automata state transitions
correspond to threshold events and the automata states correspond to
portions of the threshold surfaces in the continuous state space. The
hybrid system dynamics are approximated by the automata models in the
sense that the languages of threshold event sequences generated by the
automata contain the threshold event language for the hybrid system.
Properties of the algorithm for constructing and refining the
approximating automata are demonstrated and the application of
approximating automata for system verification is illustrated for a
switching controller for an inverted pendulum. Relationships to other
approaches to hybrid system synthesis and verification are also discussed.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 30-50
Issue: 1
Volume: 6
Year: 2000
Month: 3
X-DOI: 10.1076/1387-3954(200003)6:1;1-Q;FT030
File-URL: http://hdl.handle.net/10.1076/1387-3954(200003)6:1;1-Q;FT030
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Handle: RePEc:taf:nmcmxx:v:6:y:2000:i:1:p:30-50
Template-Type: ReDIF-Article 1.0
Author-Name: O. Stursberg
Author-X-Name-First: O.
Author-X-Name-Last: Stursberg
Author-Name: S. Kowalewski
Author-X-Name-First: S.
Author-X-Name-Last: Kowalewski
Author-Name: S. Engell
Author-X-Name-First: S.
Author-X-Name-Last: Engell
Title: On the Generation of Timed Discrete Approximations for Continuous Systems
Abstract:
In this contribution we present two procedures to
systematically derive timed discrete approximations from continuous
models. Both methods are based on a rectangular state space partition and
aim at mapping continuous dynamic behaviours described by ODE-systems with
switched inputs onto timed state transition systems: In the first approach
the transitions between the discrete states are determined by analysing
the flow between rectangular cells of the state space. The second one uses
numerical integration of the ODE-system between partitions of the
boundaries of the cells. The application of both approaches is illustrated
by a chemical process example. The paper discusses completeness and
consistency properties of the approximation mappings as well as issues of
accuracy and computational effort.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 51-70
Issue: 1
Volume: 6
Year: 2000
Month: 3
X-DOI: 10.1076/1387-3954(200003)6:1;1-Q;FT051
File-URL: http://hdl.handle.net/10.1076/1387-3954(200003)6:1;1-Q;FT051
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Template-Type: ReDIF-Article 1.0
Author-Name: Olaf Müller
Author-X-Name-First: Olaf
Author-X-Name-Last: Müller
Author-Name: Thomas Stauner
Author-X-Name-First: Thomas
Author-X-Name-Last: Stauner
Title: Modelling and Verification using Linear Hybrid Automata -- a Case Study
Abstract:
This paper discusses the use of hybrid automata to specify
and verify embedded distributed systems, that consist of both discrete and
continuous components. The basis of the evaluation is an automotive
control system, which controls the height of an automobile by pneumatic
suspension. It has been proposed by BMW AG as a case study taken from a
current industrial development. Essential parts of the system have been
modelled as hybrid automata and for appropiate ions several safety
properties have been verified. The verification has been performed using
HYTECH, a symbolic model checker for linear hybrid automata. The paper
discusses the general appropiateness of hybrid automata to specify hybrid
systems as well as advantages and drawbacks of the applied model-checking
techniques.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 71-89
Issue: 1
Volume: 6
Year: 2000
Month: 3
X-DOI: 10.1076/1387-3954(200003)6:1;1-Q;FT071
File-URL: http://hdl.handle.net/10.1076/1387-3954(200003)6:1;1-Q;FT071
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Template-Type: ReDIF-Article 1.0
Author-Name: R. Kübler
Author-X-Name-First: R.
Author-X-Name-Last: Kübler
Author-Name: W. Schiehlen
Author-X-Name-First: W.
Author-X-Name-Last: Schiehlen
Title: Two Methods of Simulator Coupling
Abstract:
Modelling and simulation of complex engineering systems are
often relieved by a modular approach in which the global system is
decomposed into subsystems. Advantages arise from independent and parallel
modelling of subsystems over easy exchange of the resulting modules to the
use of different software for each module. However, the modular simulation
of the global system by coupling of simulators may result in an unstable
integration, if an algebraic loop exists between the subsystems. This
numerical phenomenon is analyzed and two methods of simulator coupling
which guarantee stability for general systems including algebraic loops
are introduced. Numerical results of the modular simulation of a multibody
system are presented.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 93-113
Issue: 2
Volume: 6
Year: 2000
Month: 6
X-DOI: 10.1076/1387-3954(200006)6:2;1-M;FT093
File-URL: http://hdl.handle.net/10.1076/1387-3954(200006)6:2;1-M;FT093
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Template-Type: ReDIF-Article 1.0
Author-Name: M. Günther
Author-X-Name-First: M.
Author-X-Name-Last: Günther
Title: A Joint DAE/PDE Model for Interconnected Electrical Networks
Abstract:
To model transmission lines effects in integrated circuits,
we couple the network equations for the circuits with the telegrapher's
equations for the transmission lines. This results in an initial/boundary
value problem for a mixed system of Differential-Algebraic Equations
(DAEs) and hyperbolic Partial Differential Equations (PDEs). By
semidiscretization the system is transformed into differential-algebraic
equations in time only. We apply this modeling approach to a CMOS ring
oscillator, an oscillatory circuit with transmission lines as coupling
units, and discuss the simulation results.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 114-128
Issue: 2
Volume: 6
Year: 2000
Month: 6
X-DOI: 10.1076/1387-3954(200006)6:2;1-M;FT114
File-URL: http://hdl.handle.net/10.1076/1387-3954(200006)6:2;1-M;FT114
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Template-Type: ReDIF-Article 1.0
Author-Name: B. Simeon
Author-X-Name-First: B.
Author-X-Name-Last: Simeon
Author-Name: M. Arnold
Author-X-Name-First: M.
Author-X-Name-Last: Arnold
Title: Coupling DAEs and PDEs for Simulating the Interaction of Pantograph and Catenary
Abstract:
Recently, the dynamical simulation of pantograph and catenary
in high speed trains has found much interest. The equations of motion form
a coupled system of partial differential equations (PDEs) for the catenary
and differential-algebraic equations (DAEs) for the pantograph. Standard
approaches intertwine modelling and numerical solution by first
discretizing some parts in space and then setting up the overall model.
The alternative we propose is a descriptor form model which comprises all
equations and coupling conditions before discretization. This descriptor
form represents also an example for a certain class of mechanical systems
with constraints that can be subsumed under the term partial
differential-algebraic equation (PDAE).
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 129-144
Issue: 2
Volume: 6
Year: 2000
Month: 6
X-DOI: 10.1076/1387-3954(200006)6:2;1-M;FT129
File-URL: http://hdl.handle.net/10.1076/1387-3954(200006)6:2;1-M;FT129
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Handle: RePEc:taf:nmcmxx:v:6:y:2000:i:2:p:129-144
Template-Type: ReDIF-Article 1.0
Author-Name: Emanuele Carpanzano
Author-X-Name-First: Emanuele
Author-X-Name-Last: Carpanzano
Title: Order Reduction of General Nonlinear DAE Systems by Automatic Tearing
Abstract:
The object-oriented approach to modelling has recently made
possible to build models of large-scale real systems. However, the
resulting system of equations is generally a nonlinear DAE (Differential
Algebraic Equations) system of large dimension, which must be reduced in
some way to make it tractable for numerical solutions. A way to do this is
automatic symbolic tearing, which aims at splitting the DAE system into
two parts: a core consisting of a reduced implicit DAE system and a set of
explicit assignments. The problem is here dealt with by a graph theoretic
approach, first proving the NP-completeness in the general case, then
formulating the problem with reference to a bipartite graph and finally
defining an efficient and flexible algorithm for automatic tearing. It is
also shown how the proposed algorithm can easily incorporate both general
and domain-specific heuristic rules, and can also be used to deal with
equations in vector form. The application to serial multibody systems is
considered as a significant example.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 145-168
Issue: 2
Volume: 6
Year: 2000
Month: 6
X-DOI: 10.1076/1387-3954(200006)6:2;1-M;FT145
File-URL: http://hdl.handle.net/10.1076/1387-3954(200006)6:2;1-M;FT145
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Template-Type: ReDIF-Article 1.0
Author-Name: G. Mušic
Author-X-Name-First: G.
Author-X-Name-Last: Mušic
Author-Name: D. Matko
Author-X-Name-First: D.
Author-X-Name-Last: Matko
Author-Name: B. Zupancic
Author-X-Name-First: B.
Author-X-Name-Last: Zupancic
Title: Modelling, Synthesis, and Simulation of Supervisory Process Control Systems
Abstract:
Modelling, synthesis, and simulation issues of the
supervisory systems in process control are investigated in the paper.
Petri nets are used as a basic modelling framework for the supervisory
part of the system. It is shown how the final verification effort can be
minimised by applying formal synthesis methods. A straightforward approach
to the industrial implementation of the developed solutions is suggested
by means of sequential function chart representation. A batch process cell
case study is used to illustrate the described concepts. Corresponding
continuous and discrete event models of the process cell units are
developed and a co-ordinating supervisor is designed by the method of
place invariants. The system is simulated by the continuous simulation
tool Matlab-Simulink, which is enhanced for simulation of the sequential
control logic represented by sequential function chart.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 169-189
Issue: 2
Volume: 6
Year: 2000
Month: 6
X-DOI: 10.1076/1387-3954(200006)6:2;1-M;FT169
File-URL: http://hdl.handle.net/10.1076/1387-3954(200006)6:2;1-M;FT169
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Template-Type: ReDIF-Article 1.0
Author-Name: S. Zitta
Author-X-Name-First: S.
Author-X-Name-Last: Zitta
Author-Name: K. Stoschitzky
Author-X-Name-First: K.
Author-X-Name-Last: Stoschitzky
Author-Name: R. Zweiker
Author-X-Name-First: R.
Author-X-Name-Last: Zweiker
Author-Name: T. Lang
Author-X-Name-First: T.
Author-X-Name-Last: Lang
Author-Name: H. Holzer
Author-X-Name-First: H.
Author-X-Name-Last: Holzer
Author-Name: F. Mayer
Author-X-Name-First: F.
Author-X-Name-Last: Mayer
Author-Name: G. Reibnegger
Author-X-Name-First: G.
Author-X-Name-Last: Reibnegger
Author-Name: W. Estelberer
Author-X-Name-First: W.
Author-X-Name-Last: Estelberer
Title: Determination of Renal Reserve Capacity by Identification of Kinetic Systems
Abstract:
A method of adapting two-compartment models to dynamic marker
concentration profiles for the determination of renal clearance and of its
acute changes due to protein ingestion in patients with essential
hypertension is described. In 9 healthy controls glomerular filtration
rates (GFR) and effective renal plasma flows (ERPF) (ml/min/1.73 m2; means
+/- sd) rose significantly tested pairwise from 118.2 +/- 13.9 to 139.5
+/- 30.9, p = 0.023 and from 503.2 +/- 75.6 to 558.3 +/- 96.2, p = 0.013,
respectively. Four patients with mild hypertension and mean arterial
pressure (MAP) of 106 +/- 3 mmHg (duration = 13.8 +/- 10.3 years) showed
rises in GFR (73.9 +/- 14.7 to 83.6 +/- 17.4, p = 0.034) after
stimulation, whereas 6 patients with a MAP of 119 +/- 3 mmHg (duration =
17.5 +/- 13.7 years) exhibited ‘paradoxical’ decreases in
GFR (113.3 +/- 18.7 to 103.0 +/- 14.3, p = 0.037). The ERPFs showed
nonsignificant changes in the first group of patients (277.8 +/- 52.6 to
323.9 +/- 42.8), whereas the second group revealed increases in ERPF
(430.7 +/- 134.5 to 502.3 +/- 113.1, p = 0.013). All patients had normal
serum creatinine levels. The study demonstrates that modern system
identification of kinetic experiments, but not traditional techniques
relying on steady-state data, allow one to detect such dynamic alterations
as measures of renal functional reserve.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 190-207
Issue: 2
Volume: 6
Year: 2000
Month: 6
X-DOI: 10.1076/1387-3954(200006)6:2;1-M;FT190
File-URL: http://hdl.handle.net/10.1076/1387-3954(200006)6:2;1-M;FT190
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Template-Type: ReDIF-Article 1.0
Author-Name: Jang Bong-Choon
Author-X-Name-First: Jang
Author-X-Name-Last: Bong-Choon
Author-Name: Dean Karnopp
Author-X-Name-First: Dean
Author-X-Name-Last: Karnopp
Title: On the Dynamics of Gear Shifting
Abstract:
Continuously or discretely variable transmissions are used in
a variety of machines to match prime mover characteristics to varying
loads. In most cases, the transmissions provide a fairly rigid constraint
on the motions of inertial elements associated with the prime mover and
the load although compliance will allow some high frequency oscillatory
behavior. In this paper, compliance effects are neglected and the emphasis
is on correct representations of impulsive forces associated with rapid
gear ratio changes. The aim is to represent jumps in speeds, momenta and
energy at the shifting times. This allows an efficient computer model of
the overall system dynamics to be made without the necessity of
representing the high frequency dynamics of the transmission itself. Bond
graph models of automotive systems will be used to illustrate some of the
pitfalls associated with models of various types of shiftable
transmissions but the concepts apply to a wide variety of machines.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 209-221
Issue: 3
Volume: 6
Year: 2000
Month: 9
X-DOI: 10.1076/1387-3954(200009)6:3;1-I;FT209
File-URL: http://hdl.handle.net/10.1076/1387-3954(200009)6:3;1-I;FT209
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Handle: RePEc:taf:nmcmxx:v:6:y:2000:i:3:p:209-221
Template-Type: ReDIF-Article 1.0
Author-Name: H. Behrens
Author-X-Name-First: H.
Author-X-Name-Last: Behrens
Author-Name: P. Jaschke
Author-X-Name-First: P.
Author-X-Name-Last: Jaschke
Author-Name: J. Steinhausen
Author-X-Name-First: J.
Author-X-Name-Last: Steinhausen
Author-Name: H. Waller
Author-X-Name-First: H.
Author-X-Name-Last: Waller
Title: Modelling of Technical Systems: Application to Hydrodynamic Torque Converters and Couplings
Abstract:
First a short survey of modelling of technical systems is
presented. The different methods of modelling are applied to hydrodynamic
torque converters and couplings. The results of linear modelling around an
operating point, of nonlinear modelling for larger operating areas and of
hybrid modelling using simplified physical laws are illustrated.
Simulations for large excitations show the validity of the models. The
advantages and disadvantages of the different methods are discussed.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 223-250
Issue: 3
Volume: 6
Year: 2000
Month: 9
X-DOI: 10.1076/1387-3954(200009)6:3;1-I;FT223
File-URL: http://hdl.handle.net/10.1076/1387-3954(200009)6:3;1-I;FT223
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Handle: RePEc:taf:nmcmxx:v:6:y:2000:i:3:p:223-250
Template-Type: ReDIF-Article 1.0
Author-Name: B.O. Ciocirlan
Author-X-Name-First: B.O.
Author-X-Name-Last: Ciocirlan
Author-Name: D.B. Marghitu
Author-X-Name-First: D.B.
Author-X-Name-Last: Marghitu
Title: Nonlinear Analysis of an Electromagnetically Levitated Droplet
Abstract:
In this paper, a nonlinear dynamics analysis of the
experimental data was considered to study the time evolution of an
electromagnetically levitated droplet. The main goals of this work are to
decide whether the motion of the droplet is deterministic and to
investigate its stability. Quantities characterizing time series data such
as attractor dimension or largest Lyapunov exponent were computed. The
number of degrees of freedom in the system was also assessed. Data
acquired from a levitation instrument developed by Space Power Institute
at Auburn University was used to perform the analysis.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 251-265
Issue: 3
Volume: 6
Year: 2000
Month: 9
X-DOI: 10.1076/1387-3954(200009)6:3;1-I;FT251
File-URL: http://hdl.handle.net/10.1076/1387-3954(200009)6:3;1-I;FT251
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Handle: RePEc:taf:nmcmxx:v:6:y:2000:i:3:p:251-265
Template-Type: ReDIF-Article 1.0
Author-Name: S. Bourrel
Author-X-Name-First: S.
Author-X-Name-Last: Bourrel
Author-Name: D. Dochain
Author-X-Name-First: D.
Author-X-Name-Last: Dochain
Title: Stability Analysis of Two Linear Distributed Parameter Bioprocess Models
Abstract:
This paper proposes to extend the dynamical analysis results
on chemical tubular reactors presented in [5] to two linear distributed
parameter models. These are in particular the linearized tangent models of
two typical bioprocess models: a basic tubular bioreactor model, and a
denitrifying biofilter model. The tools used for the analysis are those of
the infinite dimensional system theory (e.g., [2]). In the paper we show
the existence of solutions for the studied models, and emphasize stability
conditions.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 267-281
Issue: 3
Volume: 6
Year: 2000
Month: 9
X-DOI: 10.1076/1387-3954(200009)6:3;1-I;FT267
File-URL: http://hdl.handle.net/10.1076/1387-3954(200009)6:3;1-I;FT267
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Handle: RePEc:taf:nmcmxx:v:6:y:2000:i:3:p:267-281
Template-Type: ReDIF-Article 1.0
Author-Name: F. TRÄNKLE
Author-X-Name-First: F.
Author-X-Name-Last: TRÄNKLE
Author-Name: M. ZEITZ
Author-X-Name-First: M.
Author-X-Name-Last: ZEITZ
Author-Name: M. GINKEL
Author-X-Name-First: M.
Author-X-Name-Last: GINKEL
Author-Name: E.D. GILLES
Author-X-Name-First: E.D.
Author-X-Name-Last: GILLES
Title: PROMOT: A Modeling Tool for Chemical Processes
Abstract:
The novel process modeling tool PROMOT supports the
object-oriented modeling of chemical processes for the simulation
environment DIVA. In PROMOT, differential-algebraic process models can be
built by aggregating structural and behavioral modeling entities that
represent the topological structure or the dynamic and steady-state
behavior, respectively, of the investigated chemical processes. Process
models and their modeling entities may be defined either in an
object-oriented modeling language or with a graphical user interface. This
paper discusses the modeling concept, the modeling language, the knowledge
representation aspects, and the implementation of PROMOT.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 283-307
Issue: 3
Volume: 6
Year: 2000
Month: 9
X-DOI: 10.1076/1387-3954(200009)6:3;1-I;FT283
File-URL: http://hdl.handle.net/10.1076/1387-3954(200009)6:3;1-I;FT283
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Template-Type: ReDIF-Article 1.0
Author-Name: Peter Eberhard
Author-X-Name-First: Peter
Author-X-Name-Last: Eberhard
Author-Name: Shoushan Jiang
Author-X-Name-First: Shoushan
Author-X-Name-Last: Jiang
Title: Collision Detection Using Interpolation Schemes
Abstract:
An algorithm using interpolation methods for the efficient
search of the collision time and state of planar bodies is presented.
Using interpolation and directed distances, the algorithm can efficiently
obtain information about the collision. Further, a simulation system for
multiple bodies is investigated and for some simple examples comparisons
are shown of the proposed method and a traditional approach.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 309-322
Issue: 3
Volume: 6
Year: 2000
Month: 9
X-DOI: 10.1076/1387-3954(200009)6:3;1-I;FT309
File-URL: http://hdl.handle.net/10.1076/1387-3954(200009)6:3;1-I;FT309
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Handle: RePEc:taf:nmcmxx:v:6:y:2000:i:3:p:309-322
Template-Type: ReDIF-Article 1.0
Author-Name: M. WEISS
Author-X-Name-First: M.
Author-X-Name-Last: WEISS
Author-Name: H.A. PREISIG
Author-X-Name-First: H.A.
Author-X-Name-Last: PREISIG
Title: Structural Analysis in the Dynamical Modelling of Chemical Engineering Systems
Abstract:
The dynamical modelling of physical (bio-)chemical processes
based on first principles considerations is analysed from a structural
point of view. Based on a classification of the variables and equations
that occur in such models, we propose a general framework that can help to
organise the model in a transparent way and to analyse efficiently its
solv- ability properties. We show that a well-known tool in the theory of
nonlinear dynamical systems, the Zero Dynamics Algorithm, can be used in
the analysis of higher index mod- els and also in index reduction. The
symbolic computations involved in this algorithm are readily available in
the form of nonlinear system analysis packages. The proposed methods are
illustrated by a few simple concrete examples. Keywords : First principles
modelling, differential-algebraic systems, index reduction.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 325-364
Issue: 4
Volume: 6
Year: 2000
Month: 12
X-DOI: 10.1076/mcmd.6.4.325.3656
File-URL: http://hdl.handle.net/10.1076/mcmd.6.4.325.3656
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Handle: RePEc:taf:nmcmxx:v:6:y:2000:i:4:p:325-364
Template-Type: ReDIF-Article 1.0
Author-Name: S.P. BERGE
Author-X-Name-First: S.P.
Author-X-Name-Last: BERGE
Author-Name: T.I. FOSSEN
Author-X-Name-First: T.I.
Author-X-Name-Last: FOSSEN
Title: On the Properties of the Nonlinear Ship Equations of Motion
Abstract:
Nonlinear ship control systems can be designed by exploiting
system properties like passivity and dissipativeness in nonlinear system.
The nonlinear ship model is written in a vectorial setting with emphasis
placed on matrix properties like positiveness, symmetry and skew-symmetry.
As a result of energy conservation the ship dynamics can be considered as
two interconnected systems. The first system describes the dissipative
motion of the rigid-body (ship) while the second system represents the
forces due to potential theory generated by the ambient water particles.
It is shown that for a stable ship, both subsystems are passive as well as
the interconnected system. For an unstable ship, the ambient water system
is input feedforward passive with shortage of passivity and therefore the
ship must be stabilized by positive feedback. The structural properties of
the nonlinear equations of motion are exploited in the Lyapunov analysis
when designing ship control systems.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 365-381
Issue: 4
Volume: 6
Year: 2000
Month: 12
X-DOI: 10.1076/mcmd.6.4.365.3660
File-URL: http://hdl.handle.net/10.1076/mcmd.6.4.365.3660
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Handle: RePEc:taf:nmcmxx:v:6:y:2000:i:4:p:365-381
Template-Type: ReDIF-Article 1.0
Author-Name: PETER BENNER
Author-X-Name-First: PETER
Author-X-Name-Last: BENNER
Author-Name: ENRIQUE S. QUINTANA-ORTí
Author-X-Name-First: ENRIQUE S.
Author-X-Name-Last: QUINTANA-ORTí
Author-Name: GREGORIO QUINTANA-ORTí
Author-X-Name-First: GREGORIO
Author-X-Name-Last: QUINTANA-ORTí
Title: Balanced Truncation Model Reduction of Large-Scale Dense Systems on Parallel Computers
Abstract:
Model reduction is an area of fundamental importance in many
modeling and control applications. In this paper we analyze the use of
parallel computing in model reduction methods based on balanced truncation
of large-scale dense systems. The methods require the computation of the
Gramians of a linear-time invariant system. Using a sign function-based
solver for computing full-rank factors of the Gramians yields some
favorable computational aspects in the subsequent computation of the
reduced-order model, particularly for non-minimal systems. As sign
function-based computations only require efficient implementations of
basic linear algebra operations readily available, e.g., in the BLAS,
LAPACK, and ScaLAPACK, good performance of the resulting algorithms on
parallel computers is to be expected. Our experimental results on a PC
cluster show the performance and scalability of the parallel
implementation.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 383-405
Issue: 4
Volume: 6
Year: 2000
Month: 12
X-DOI: 10.1076/mcmd.6.4.383.3658
File-URL: http://hdl.handle.net/10.1076/mcmd.6.4.383.3658
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Handle: RePEc:taf:nmcmxx:v:6:y:2000:i:4:p:383-405
Template-Type: ReDIF-Article 1.0
Author-Name: Béla Palácz
Author-X-Name-First: Béla
Author-X-Name-Last: Palácz
Title: Modelling and Simulation of Heat and Mass Transfer, via Symbolic Computation
Abstract:
This basically tutorial/case study paper illustrates the
application of symbolic computation for two classical cases of chemical
engineering, namely the modelling and simulation of a heat transfer
process intensified by fin-covered surface, and a convective mass
transport with first order irreversible chemical reaction. It has been
shown that computer algebra provides a comfortable and elegant way to
solve such technical problems in fully analytical form, with standard
mathematical knowledge.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 407-424
Issue: 4
Volume: 6
Year: 2000
Month: 12
X-DOI: 10.1076/mcmd.6.4.407.3657
File-URL: http://hdl.handle.net/10.1076/mcmd.6.4.407.3657
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Handle: RePEc:taf:nmcmxx:v:6:y:2000:i:4:p:407-424
Template-Type: ReDIF-Article 1.0
Author-Name: Dennis D. Sourlas
Author-X-Name-First: Dennis D.
Author-X-Name-Last: Sourlas
Title: On Process Model Order Reduction for Controller Design in Discrete Systems
Abstract:
This paper studies the model reduction problem with emphasis
on closed loop performance. First, the admissible fixed order models are
identified as the ones that are simultaneously stabilizable with the high
order process. A complete parametrization of this set in terms of stable
parameters that satisfy cubic equality constraints is developed. An
optimization problem is then formulated so that its solution identifies
the fixed order model that satisfies nominal performance specifications,
it is simultaneously stabilizable with the actual process and the actual
closed loop optimally satisfies the nominal performance specifications.
This nonlinear, infinite dimensional optimization problem is solved by
means of exact penalty functions and an asymptotic approximation
procedure. An illustrative example is also presented.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 425-444
Issue: 4
Volume: 6
Year: 2000
Month: 12
X-DOI: 10.1076/mcmd.6.4.425.3659
File-URL: http://hdl.handle.net/10.1076/mcmd.6.4.425.3659
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Handle: RePEc:taf:nmcmxx:v:6:y:2000:i:4:p:425-444
Template-Type: ReDIF-Article 1.0
Author-Name: S.A. STEVENS
Author-X-Name-First: S.A.
Author-X-Name-Last: STEVENS
Author-Name: W.D. LAKIN
Author-X-Name-First: W.D.
Author-X-Name-Last: LAKIN
Title: Local Compliance Effects on the Global Pressure-Volume Relationship in Models of Intracranial Pressure Dynamics
Abstract:
The experimentally-measured pressure-volume relationship for
the human intracranial system is a nonlinear ‘S-shaped’
curve with two pressure plateaus, a point of inflection, and a vertical
asymptote at high pressures where all capacity for volume compensation is
lost. In lumped-parameter mathematical models of the intracranial system,
local compliance parameters relate volume adjustments to dynamic changes
in pressure differences between adjacent model subunits. This work
explores the relationship between the forms used for local model
compliances and the calculated global pressure-volume relationship. It is
shown that the experimentally-measured global relationship can be
recovered using physiologically motivated expressions for the local
compliances at the interfaces between the venous-cerebrospinal fluid (CSF)
subunits and arterial-CSF subunits in the model. Establishment of a
consistent link between local model compliances and the physiological bulk
pressure-volume relationship is essential if lumped-parameter models are
to be capable of realistically predicting intracranial pressure dynamics.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 445-465
Issue: 4
Volume: 6
Year: 2000
Month: 12
X-DOI: 10.1076/mcmd.6.4.445.3655
File-URL: http://hdl.handle.net/10.1076/mcmd.6.4.445.3655
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Handle: RePEc:taf:nmcmxx:v:6:y:2000:i:4:p:445-465
Template-Type: ReDIF-Article 1.0
Author-Name: P. M. FRANK
Author-X-Name-First: P. M.
Author-X-Name-Last: FRANK
Author-Name: E. ALCORTA GARCIA
Author-X-Name-First: E. ALCORTA
Author-X-Name-Last: GARCIA
Author-Name: B. KÖPPEN-SELIGER
Author-X-Name-First: B.
Author-X-Name-Last: KÖPPEN-SELIGER
Title: Modelling for Fault Detection and Isolation versus Modelling for Control
Abstract:
The main purpose of this paper is to emphasize the
particularities of models needed for model-based fault detection and
isolation (FDI) in contrast to the models used for control. Of special
interest is the question of complexity of the model, which is of great
importance for the practical implementation. This, of course, depends
basically on the given situation such as the kind of plant, the
measurements, the kind and number of faults to be detected and the demands
for fault isolation and robustness. However, the paper shows that
diagnostic models, in contrast to the wide-spread opinion that those have
always to be more complex than the functional models for control, may be
even less complex, because they are restricted to only those parts of the
system in which the faults occur. The issue of model complexity is
discussed in terms of different model-based FDI approaches analytical,
knowledge-based and data-based. The ideas are illustrated in a case study,
where several types of model-based FDI techniques are compared with the
same plant, the amira three tank system.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 1-46
Issue: 1
Volume: 7
Year: 2001
Month: 3
X-DOI: 10.1076/mcmd.7.1.1.3633
File-URL: http://hdl.handle.net/10.1076/mcmd.7.1.1.3633
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Handle: RePEc:taf:nmcmxx:v:7:y:2001:i:1:p:1-46
Template-Type: ReDIF-Article 1.0
Author-Name: O.M. AAMO
Author-X-Name-First: O.M.
Author-X-Name-Last: AAMO
Author-Name: T.I. FOSSEN
Author-X-Name-First: T.I.
Author-X-Name-Last: FOSSEN
Title: Finite Element Modelling of Moored Vessels
Abstract:
In this paper, we develop a new finite element model for a
cable suspended in water. Global existence and uniqueness of solutions of
the truncated system is shown for a slightly simplified equation
describing the motion of a cable with negligible added mass and supported
by fixed end-points. Based on this, along with well known results on local
existence and uniqueness of solutions for symmetrizable hyperbolic
systems, we conjecture a global result for the initial-boundary value
problem. The FEM model for the cable is assembled to give a model of a
multi-cable mooring system, which, in turn, is coupled to a rigid body
model of the floating vessel. The result is a coupled dynamical model of a
moored vessel, which can be applied to applications such as turret-based
moored ships, or tension leg platforms.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 47-75
Issue: 1
Volume: 7
Year: 2001
Month: 3
X-DOI: 10.1076/mcmd.7.1.47.3632
File-URL: http://hdl.handle.net/10.1076/mcmd.7.1.47.3632
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Handle: RePEc:taf:nmcmxx:v:7:y:2001:i:1:p:47-75
Template-Type: ReDIF-Article 1.0
Author-Name: A. GIUA
Author-X-Name-First: A.
Author-X-Name-Last: GIUA
Author-Name: M. SANNA
Author-X-Name-First: M.
Author-X-Name-Last: SANNA
Author-Name: C. SEATZU
Author-X-Name-First: C.
Author-X-Name-Last: SEATZU
Title: Observer-Controller Design for Three Dimensional Overhead Cranes Using Time-Scaling
Abstract:
In this paper we address the design of an observer-controller
for a three degrees of freedom overhead crane. We consider a linear model
of the crane where the length of the suspending rope is a time-varying
parameter. The set of models given by frozen values of the rope length can
be reduced to a single time-invariant reference model using suitable
time-scalings. We construct a controller and an observer for the reference
model assigning the desired closed loop eigenvalues for both system and
estimation error. The time-scaling relations can be used to derive a
control law for the time-varying system that implements an implicit
gain-scheduling [6]. A second gain-scheduling is used to choose suitable
closed-loop eigenvalues for different values of the load and
lifting/lowering operations. Using a Lyapunov-like theorem, it is also
possible to find relative upper bounds for the rate of change of the
varying parameter that ensure the stability of the time-varying system.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 77-107
Issue: 1
Volume: 7
Year: 2001
Month: 3
X-DOI: 10.1076/mcmd.7.1.77.3634
File-URL: http://hdl.handle.net/10.1076/mcmd.7.1.77.3634
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Handle: RePEc:taf:nmcmxx:v:7:y:2001:i:1:p:77-107
Template-Type: ReDIF-Article 1.0
Author-Name: G. AMBROSINO
Author-X-Name-First: G.
Author-X-Name-Last: AMBROSINO
Author-Name: G. CELENTANO
Author-X-Name-First: G.
Author-X-Name-Last: CELENTANO
Author-Name: M. MATTEI
Author-X-Name-First: M.
Author-X-Name-Last: MATTEI
Title: A Control Design Oriented Mathematical Model for the Scirocco Plasma Wind Tunnel
Abstract:
In this paper the mathematical model of a modern arc heated
Plasma Wind Tunnel used to test parts of space vehicles during the
re-entry phase is presented. Due to the complexity of the physical
processes arising during the operating of the plant, a number of
simplification is proposed to obtain a control design oriented fast and
efficient simulation software. Such a software was successfully used
during the design phase to become confident with the dynamic behavior of
the facility and to achieve a process-control integrated design. During
the operating life of the wind tunnel it will be used to support the test
engineers in the design of the control laws for the tracking of the
desired trajectories in temperature and pressure on the test article. A
short description of the test control algorithm which is based on the
above model is also provided.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 109-127
Issue: 1
Volume: 7
Year: 2001
Month: 3
X-DOI: 10.1076/mcmd.7.1.109.3635
File-URL: http://hdl.handle.net/10.1076/mcmd.7.1.109.3635
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Handle: RePEc:taf:nmcmxx:v:7:y:2001:i:1:p:109-127
Template-Type: ReDIF-Article 1.0
Author-Name: P.C. Müller
Author-X-Name-First: P.C.
Author-X-Name-Last: Müller
Author-Name: B. Simeon
Author-X-Name-First: B.
Author-X-Name-Last: Simeon
Title: Editorial Differential-Algebraic Equations and Descriptor Systems
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 131-132
Issue: 2
Volume: 7
Year: 2001
Month: 6
X-DOI: 10.1076/mcmd.7.2.131.3652
File-URL: http://hdl.handle.net/10.1076/mcmd.7.2.131.3652
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Handle: RePEc:taf:nmcmxx:v:7:y:2001:i:2:p:131-132
Template-Type: ReDIF-Article 1.0
Author-Name: P.C. Müller
Author-X-Name-First: P.C.
Author-X-Name-Last: Müller
Title: Aspects of Modeling Dynamical Systems by Differential-Algebraic Equations
Abstract:
In recent years the analysis and synthesis of control systems
in descriptor form has been established. The general description of
dynamical systems by differential-algebraic equations (DAE) is important
for many applications in mechanics and mechatronics, in electrical and
electronic engineering, and in chemical engineering as well. In this
contribution the pros and cons of system modelling by
differential-algebraic equations are discussed and an actual state of the
art of descriptor systems is presented. Firstly, the advantages of
modelling are touched in general and illustrated in detail by Lagranges
equations of first kind, by subsystem modeling and by the statement of the
tracking control problem. Secondly, the development of tools for numerical
integration is discussed resulting in the comment that today stable and
efficient DAE solvers exist and that the simulation of descriptor systems
is not a problem any longer. Thirdly, the methods of analyzing and
designing descriptor systems are considered. Here, linear and nonlinear
systems have to be distinguished. For linear descriptor systems more or
less the required methods to solve usual control tasks are available in
principal. But actually a related program package for fast and reliable
application of these methods is still missed. However, in the near future
such a toolbox is expected. Main difficulties arise for nonlinear
problems. A few results on stability and optimal control are known only
and still a lot of research work has to be effected. In spite of these
deficiencies, all over the descriptor system approach is very attractive
for modeling and simulation, and will become attractive more and more for
analysis and design.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 133-143
Issue: 2
Volume: 7
Year: 2001
Month: 6
X-DOI: 10.1076/mcmd.7.2.133.3650
File-URL: http://hdl.handle.net/10.1076/mcmd.7.2.133.3650
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Handle: RePEc:taf:nmcmxx:v:7:y:2001:i:2:p:133-143
Template-Type: ReDIF-Article 1.0
Author-Name: C. Kraus
Author-X-Name-First: C.
Author-X-Name-Last: Kraus
Author-Name: M. Winckler
Author-X-Name-First: M.
Author-X-Name-Last: Winckler
Author-Name: H.G. Bock
Author-X-Name-First: H.G.
Author-X-Name-Last: Bock
Title: Modeling Mechanical DAE Using Natural Coordinates
Abstract:
An efficient modeling technique for multibody systems, which
extends the concept of natural coordinates with closed kinematic loops is
presented. By establishing a local coordinate system in each body a system
with constant mass matrix is set up. The propagation of topological
information into the model leads to the application of a block-oriented
rational Cholesky decomposition of the system matrix. The overall
algorithm shows linear complexity in the number of bodies for systems with
a constant number of kinematic loops. To handle rank-deficient constraint
Jacobians arising from loop closing conditions the concept of constraint
partitioning during decomposition is outlined. Restriction of the
partitioning decision based on the topology information minimizes the
monitoring effort and avoids disadvantages experienced in other
partitioning methods. Numerical results for the 6-bar-mechanism proof the
algorithm to run efficiently with projection stabilized index-1
integration methods.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 145-158
Issue: 2
Volume: 7
Year: 2001
Month: 6
X-DOI: 10.1076/mcmd.7.2.145.3645
File-URL: http://hdl.handle.net/10.1076/mcmd.7.2.145.3645
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Handle: RePEc:taf:nmcmxx:v:7:y:2001:i:2:p:145-158
Template-Type: ReDIF-Article 1.0
Author-Name: K. Schlacher
Author-X-Name-First: K.
Author-X-Name-Last: Schlacher
Author-Name: A. Kugi
Author-X-Name-First: A.
Author-X-Name-Last: Kugi
Title: Descriptor-Systems and Optimal Control
Abstract:
Many problems in mathematical modeling of lumped parameter
systems lead to sets of mixed ordinary differential and algebraic
equations. A natural generalization are so called descriptor systems or
sets of implicit ordinary differential equations, which are linear in the
derivatives. This contribution deals with variational problems for
descriptor systems. Using the mathematical language of Pfaffian systems,
we derive a canonical form of a descriptor system, which can be converted
to an explicit control system in principle. Since the proposed approach
does not use this transform explicitly, the Euler Lagrange and Hamilton
Jacobi equations of the variational problem are derivable by pure
algebraic manipulations. In addition, this approach leads to computer
algebra based algorithms, which are needed to perform the required
calculations efficiently.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 159-172
Issue: 2
Volume: 7
Year: 2001
Month: 6
X-DOI: 10.1076/mcmd.7.2.159.3651
File-URL: http://hdl.handle.net/10.1076/mcmd.7.2.159.3651
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Handle: RePEc:taf:nmcmxx:v:7:y:2001:i:2:p:159-172
Template-Type: ReDIF-Article 1.0
Author-Name: G. Fábián
Author-X-Name-First: G.
Author-X-Name-Last: Fábián
Author-Name: D.A. Van Beek
Author-X-Name-First: D.A.
Author-X-Name-Last: Van Beek
Author-Name: J.E. Rooda
Author-X-Name-First: J.E.
Author-X-Name-Last: Rooda
Title: Index Reduction and Discontinuity Handling Using Substitute Equations
Abstract:
Several techniques exist for index reduction and consistent
initialization of higher index DAEs. Many such techniques change the
original set of equations by differentiation, substitution, and/or
introduction of new variables. This paper introduces substitute equations
as a new language element. By means of a substitute equation, the value of
a continuous variable or its time derivative is specified by an
expression. This expression is evaluated each time that the variable or
its time derivative, respectively, is referenced in the model. The
advantage of substitute equations is that they enable index reduction and
consistent initialization of higher index DAEs without changing the
original equations; no existing variables are removed and no new variables
are introduced. Substitute equations can also be used to enable the use of
general purpose numerical solvers for equations where one or more of the
unknowns are discontinuous, and they can be used to prevent functions to
be called outside of their domain.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 173-187
Issue: 2
Volume: 7
Year: 2001
Month: 6
X-DOI: 10.1076/mcmd.7.2.173.3646
File-URL: http://hdl.handle.net/10.1076/mcmd.7.2.173.3646
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Handle: RePEc:taf:nmcmxx:v:7:y:2001:i:2:p:173-187
Template-Type: ReDIF-Article 1.0
Author-Name: M. Günther
Author-X-Name-First: M.
Author-X-Name-Last: Günther
Title: A PDAE Model for Interconnected Linear RLC Networks
Abstract:
In electrical circuit simulation, a refined generalized
network approach is used to describe secondary and parasitic effects of
interconnected networks. Restricting our investigations to linear RLC
circuits, this ansatz yields linear initial-boundary value problems of
mixed partial-differential and differential-algebraic equations, so-called
PDAE systems. If the network fulfils some topological conditions, this
system is well-posed and has perturbation index 1 only: the solution of a
slightly perturbed system does not depend on derivatives of the
perturbations. As method-of-lines applications are often used to embed
PDAE models into time-domain network analysis packages, it is reasonable
to demand that the analytical properties of the approximate DAE system
obtained after semidiscretization are consistent with the original PDAE
system. Especially, both should show the same sensitivity with respect to
initial and boundary data. We will learn, however, that semidiscretization
may act like a deregularization of an index-1 PDAE model, if an
inappropriate type of semidiscretization is used.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 189-203
Issue: 2
Volume: 7
Year: 2001
Month: 6
X-DOI: 10.1076/mcmd.7.2.189.3649
File-URL: http://hdl.handle.net/10.1076/mcmd.7.2.189.3649
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Handle: RePEc:taf:nmcmxx:v:7:y:2001:i:2:p:189-203
Template-Type: ReDIF-Article 1.0
Author-Name: C. Clauß
Author-X-Name-First: C.
Author-X-Name-Last: Clauß
Author-Name: P. Schwarz
Author-X-Name-First: P.
Author-X-Name-Last: Schwarz
Author-Name: B. Straube
Author-X-Name-First: B.
Author-X-Name-Last: Straube
Author-Name: W. Vermeiren
Author-X-Name-First: W.
Author-X-Name-Last: Vermeiren
Title: Sybolical Index Calculation For Linear Circuits
Abstract:
The condition for the DAE index to be higher than one is
calculated symbolically. Using Analog Insydes a function for the computer
algera system Mathmatica is written. It calculates the index condition if
the sparse tableau analysis method, or the modified nodal analysis method
is applied.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 205-214
Issue: 2
Volume: 7
Year: 2001
Month: 6
X-DOI: 10.1076/mcmd.7.2.205.3654
File-URL: http://hdl.handle.net/10.1076/mcmd.7.2.205.3654
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Handle: RePEc:taf:nmcmxx:v:7:y:2001:i:2:p:205-214
Template-Type: ReDIF-Article 1.0
Author-Name: C. Tischendorf
Author-X-Name-First: C.
Author-X-Name-Last: Tischendorf
Author-Name: D. Estévez Schwarz
Author-X-Name-First: D.
Author-X-Name-Last: Estévez Schwarz
Title: Mathematical Problems in Circuit Simulation
Abstract:
Circuit simulation is a standard task for the computer-aided
design of electronic circuits. The transient analysis is well understood
and realized in powerful simulation packages for conventional circuits.
However, further developments in production engineering lead to new
classes of circuits, which cause difficulties for the numerical
integration. The dimension of circuit models can be quite large (10 5
equations). The complexity of the models demands a higher level of ion.
Parasitic effects become dominant. The signal to noise ratio becomes
smaller. In this paper, we want to draw attention to three essential
problems from a mathematical point of view, the DAE-index, consistent
initial values, and asymptotic stability. These topics have been
extensively analyzed only recently. We shall illustrate them by some
simple examples.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 215-223
Issue: 2
Volume: 7
Year: 2001
Month: 6
X-DOI: 10.1076/mcmd.7.2.215.3647
File-URL: http://hdl.handle.net/10.1076/mcmd.7.2.215.3647
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Handle: RePEc:taf:nmcmxx:v:7:y:2001:i:2:p:215-223
Template-Type: ReDIF-Article 1.0
Author-Name: M. Schaub
Author-X-Name-First: M.
Author-X-Name-Last: Schaub
Author-Name: B. Simeon
Author-X-Name-First: B.
Author-X-Name-Last: Simeon
Title: Pantograph-Catenary Dynamics: An Analysis of Models and Simulation Techniques
Abstract:
In this paper we analyze models and simulation techniques for
the interaction of pantograph and catenary. Detailed models for catenary
and pantograph and the propagation of waves are first investigated. Next,
the semi discretization by the finite element method and the time
integration are described. In this context numerical techniques like
GGL-stabilization and superconvergent patch recovery are applied. The
latter yields an error estimation for the finite element grid and shows
the critical points of the system.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 225-238
Issue: 2
Volume: 7
Year: 2001
Month: 6
X-DOI: 10.1076/mcmd.7.2.225.3644
File-URL: http://hdl.handle.net/10.1076/mcmd.7.2.225.3644
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Handle: RePEc:taf:nmcmxx:v:7:y:2001:i:2:p:225-238
Template-Type: ReDIF-Article 1.0
Author-Name: I. Higueras
Author-X-Name-First: I.
Author-X-Name-Last: Higueras
Title: Numerical Methods for Stiff Index-3 DAEs
Abstract:
Space semidiscretization of PDAEs, i.e. coupled systems of
PDEs and algebraic equations, give raise to stiff DAEs and thus the
standard theory of numerical methods for DAEs is not valid. As the study
of numerical methods for stiff ODEs is done in terms of logarithmic norms,
it seems natural to use also logarithmic norms for stiff DAEs. In this
paper we show how the standard conditions imposed on the PDAE and the
semidiscretized problem are formally the same if they are expressed in
terms of logarithmic norms. To study the mathematical problem and their
numerical approximations, this link between the standard conditions and
logarithmic norms allow us to use for stiff DAEs techniques similar to the
ones used for stiff ODEs. The analysis is done for problems which appear
in the context of elastic multibody systems, but once the tools, i.e.,
logarithmic norms, are developed, they can also be used for the analysis
of other PDAEs/DAEs.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 239-262
Issue: 2
Volume: 7
Year: 2001
Month: 6
X-DOI: 10.1076/mcmd.7.2.239.3648
File-URL: http://hdl.handle.net/10.1076/mcmd.7.2.239.3648
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Handle: RePEc:taf:nmcmxx:v:7:y:2001:i:2:p:239-262
Template-Type: ReDIF-Article 1.0
Author-Name: J. Schropp
Author-X-Name-First: J.
Author-X-Name-Last: Schropp
Title: Geometric Properties of Runge-Kutta Discretizations for Nonautonomous Index 2 Differential Algebraic Systems
Abstract:
We analyze Runge-Kutta discretizations applied to
nonautonomous index 2 differential algebraic equations (DAEs) in
semi-explicit form. It is shown that for half-explicit and projected
Runge-Kutta methods there is an attractive invariant manifold for the
discrete system which is close to the invariant manifold of the DAE. The
proof combines reduction techniques to autonomou index 2 differential
algebraic equations with some invariant manifold results of Schropp [9].
The results support the favourable behavior of these Runge-Kutta methods
applied to index 2 DAEs for t = 0.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 263-271
Issue: 2
Volume: 7
Year: 2001
Month: 6
X-DOI: 10.1076/mcmd.7.2.263.3653
File-URL: http://hdl.handle.net/10.1076/mcmd.7.2.263.3653
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Handle: RePEc:taf:nmcmxx:v:7:y:2001:i:2:p:263-271
Template-Type: ReDIF-Article 1.0
Author-Name: R.A. Layton
Author-X-Name-First: R.A.
Author-X-Name-Last: Layton
Author-Name: B.C. Fabien
Author-X-Name-First: B.C.
Author-X-Name-Last: Fabien
Title: Systematic Modelling Using Lagrangian DAEs
Abstract:
A treatment for formulating equations of motion for discrete
engineering systems using a differential-algebraic form of Lagrange's
equation is presented. The distinguishing characteristics of this approach
are the retention of constraints in the mathematical model and the
consequent use of dependent coordinates. A derivation of Lagrange's
equation based on the first law of thermodynamics is featured.
Nontraditional constraint classifications for Lagrangian
differential-algebraic equations (DAEs) are defined. Model formulation is
systematic and lays a foundation for developing DAE-based tools and
algorithms for applications in dynamic systems and control.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 273-304
Issue: 3
Volume: 7
Year: 2001
Month: 9
X-DOI: 10.1076/mcmd.7.3.273.3642
File-URL: http://hdl.handle.net/10.1076/mcmd.7.3.273.3642
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Handle: RePEc:taf:nmcmxx:v:7:y:2001:i:3:p:273-304
Template-Type: ReDIF-Article 1.0
Author-Name: C. Maffezzoni
Author-X-Name-First: C.
Author-X-Name-Last: Maffezzoni
Author-Name: P. Rocco
Author-X-Name-First: P.
Author-X-Name-Last: Rocco
Title: The Index of PDAEs Applied to the Modelling of a Flexible Mechanical System
Abstract:
The numerical solution of systems of partial differential and
algebraic equations (PDAEs) is strictly related to a property of the
system, the index, whose definition and role are discussed in this paper.
The notion of algebraic index is reviewed and compared to the more general
notion of perturbation index. Extensions to nonlinear PDAEs are also
proposed. Reference is then made to the case of a flexible mechanical
system (an inextensible cable), whose model is formulated in three
different, yet dynamically equivalent, ways, with different properties
with respect to the feasibility of an accurate numerical integration. The
methodology used in this analysis is finally formalized in an algorithm
for index reduction.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 305-321
Issue: 3
Volume: 7
Year: 2001
Month: 9
X-DOI: 10.1076/mcmd.7.3.305.3643
File-URL: http://hdl.handle.net/10.1076/mcmd.7.3.305.3643
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Handle: RePEc:taf:nmcmxx:v:7:y:2001:i:3:p:305-321
Template-Type: ReDIF-Article 1.0
Author-Name: Jan Fredrik Hansen
Author-X-Name-First: Jan Fredrik
Author-X-Name-Last: Hansen
Author-Name: Alf Kåre ådnanes
Author-X-Name-First: Alf Kåre
Author-X-Name-Last: ådnanes
Author-Name: Thor I. Fossen
Author-X-Name-First: Thor I.
Author-X-Name-Last: Fossen
Title: Mathematical Modelling of Diesel-Electric Propulsion Systems for Marine Vessels
Abstract:
This article presents a mathematical model of a complete
diesel-electric propulsion system, including components as diesel
generators, distribution network, variable speed thruster-drives, and
conventional motor loads. The model is split into two parts: One power
generating part where the load is specified with an aggregated active and
reactive power load demand. Secondly, a power consumption part where the
effects of the different load types as thruster drives, motors and other
loads are modelled. The model is written in a state-space form suitable
for the purpose of simulation and control design. PID-controllers
represent speed governors and automatic voltage regulators.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 323-355
Issue: 3
Volume: 7
Year: 2001
Month: 9
X-DOI: 10.1076/mcmd.7.3.323.3641
File-URL: http://hdl.handle.net/10.1076/mcmd.7.3.323.3641
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Handle: RePEc:taf:nmcmxx:v:7:y:2001:i:3:p:323-355
Template-Type: ReDIF-Article 1.0
Author-Name: L. Trautmann
Author-X-Name-First: L.
Author-X-Name-Last: Trautmann
Author-Name: R. Rabenstein
Author-X-Name-First: R.
Author-X-Name-Last: Rabenstein
Title: Turning Vector Partial Differential Equations into Multidimensional Transfer Function Models
Abstract:
Transfer function models for the description of physical
systems have recently been introduced. They provide an alternative to the
conventional representation by partial differential equations (PDE) and
are suitable for computer implementation. This paper presents transfer
function modelling for vector PDEs. They arise from the physical analysis
of multidimensional systems in terms of potential and flux quantities.
Expressing the resulting coupled PDEs in vector form facilitates the
direct formulation of boundary and interface conditions in their physical
context. It is shown how a carefully constructed transformation for the
space variable leads to transfer function models for vector PDEs. They are
the starting point for the derivation of discrete models by standard
methods for one-dimensional systems. The presented functional
transformation approach is suitable for a number of technical
applications, like electromagnetics, optics, acoustics and heat and mass
transfer. Examples are given for the voltage and current distribution on
an electrical transmission line and the velocity and force distribution on
longitudinal vibrating strings.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 357-382
Issue: 4
Volume: 7
Year: 2001
Month: 12
X-DOI: 10.1076/mcmd.7.4.357.3640
File-URL: http://hdl.handle.net/10.1076/mcmd.7.4.357.3640
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Handle: RePEc:taf:nmcmxx:v:7:y:2001:i:4:p:357-382
Template-Type: ReDIF-Article 1.0
Author-Name: Jan Lunze
Author-X-Name-First: Jan
Author-X-Name-Last: Lunze
Author-Name: Bernhard Nixdorf
Author-X-Name-First: Bernhard
Author-X-Name-Last: Nixdorf
Title: Representation of Hybrid Systems by Means of Stochastic Automata
Abstract:
In this paper hybrid systems with discrete-event measurements
and inputs are considered. Such systems consist of a continuous-variable
subsystem and a discrete-event subsystem which are connected in a closed
loop. Stochastic automata are used as models of the discrete-event
behavior of the hybrid system, which is in general non-deterministic. It
is shown that the model can be set up by, first, modeling the
discrete-event behavior of the continuous-variable subsystem by means of a
stochastic automaton. It is shown, that the transition relation of this
automaton can be derived from a continuous-variable description of the
subsystem. Second, the resulting model is combined with the model of the
discrete-event subsystem, which in general can be represented by a
deterministic automaton. As the continuous-variable subsystem and,
therefore, also the hybrid system cannot be modeled exactly by an
automaton, the model of the hybrid system generates spurious solutions.
Therefore, conditions on the model of the continuous-variable and on the
model of the hybrid system will be presented which yield the best complete
model of the hybrid system, i.e., the model which generates all event
sequences which may occur in the hybrid system and the least number of
spurious solutions.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 383-422
Issue: 4
Volume: 7
Year: 2001
Month: 12
X-DOI: 10.1076/mcmd.7.4.383.3639
File-URL: http://hdl.handle.net/10.1076/mcmd.7.4.383.3639
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Handle: RePEc:taf:nmcmxx:v:7:y:2001:i:4:p:383-422
Template-Type: ReDIF-Article 1.0
Author-Name: S. Simon
Author-X-Name-First: S.
Author-X-Name-Last: Simon
Author-Name: S. Engell
Author-X-Name-First: S.
Author-X-Name-Last: Engell
Title: Using Wavelets for the Detection of Discrete Events in Time Series of Hybrid Systems
Abstract:
This contribution deals with the use of wavelets for the
analysis of time series of systems which are hybrid in the sense that they
contain discrete and continuous dynamics. We focus on the detection of
discrete events which is an important step in the identification of hybrid
systems. A brief overview of the characteristics of the wavelet transform
is given, which shows that the wavelet transform is an appropriate method
for the analysis of time series of hybrid systems. By the combination of
two wavelet-based analysis techniques, a two-step procedure is obtained
which allows the detection of switching points in the presence of weak
noise. In this context, emphasis is given to the problems which arise when
the theoretical results are used to detect discrete events in real time
series. The procedure is demonstrated for a time series obtained from the
simulation of a nonlinear laboratory plant.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 423-442
Issue: 4
Volume: 7
Year: 2001
Month: 12
X-DOI: 10.1076/mcmd.7.4.423.3636
File-URL: http://hdl.handle.net/10.1076/mcmd.7.4.423.3636
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Handle: RePEc:taf:nmcmxx:v:7:y:2001:i:4:p:423-442
Template-Type: ReDIF-Article 1.0
Author-Name: M. Meusburger
Author-X-Name-First: M.
Author-X-Name-Last: Meusburger
Title: Modeling of a Water Power Plant
Abstract:
This paper deals with the mathematical modeling of a water
power plant. For the modeling procedure the plant was divided into logical
parts and for each of these parts an appropriate mathematical model was
developed. The interconnection of the different models is done by their
common boundary conditions. The model also has to deal with a special type
of an intersection between an open channel and a pipe flow. With suitable
assumptions it is possible to simplify the model for this special kind of
flow significantly. Finally, measurement results show the feasibility of
the proposed assumptions for this plant.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 443-453
Issue: 4
Volume: 7
Year: 2001
Month: 12
X-DOI: 10.1076/mcmd.7.4.443.3638
File-URL: http://hdl.handle.net/10.1076/mcmd.7.4.443.3638
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Handle: RePEc:taf:nmcmxx:v:7:y:2001:i:4:p:443-453
Template-Type: ReDIF-Article 1.0
Author-Name: M. Lefebvre
Author-X-Name-First: M.
Author-X-Name-Last: Lefebvre
Title: A Three-Dimensional Landing Model
Abstract:
The problem of modelling the trajectory of an airplane that
has begun to land and of optimally controlling the airplane until it
touches the ground is considered in three dimensions. Two cost criteria
are used. In the first case, the aim is to make the airplane touch the
ground as close to a given target as possible, and as soon as possible.
With the second cost criterion, we force the airplane to land inside a
certain rectangle on the ground. In each case, the optimal control is
obtained by considering the corresponding uncontrolled process.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 455-464
Issue: 4
Volume: 7
Year: 2001
Month: 12
X-DOI: 10.1076/mcmd.7.4.455.3637
File-URL: http://hdl.handle.net/10.1076/mcmd.7.4.455.3637
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Handle: RePEc:taf:nmcmxx:v:7:y:2001:i:4:p:455-464
Template-Type: ReDIF-Article 1.0
Author-Name: Magnus Nørgaard
Author-X-Name-First: Magnus
Author-X-Name-Last: Nørgaard
Author-Name: Ole Ravn
Author-X-Name-First: Ole
Author-X-Name-Last: Ravn
Author-Name: Niels Kjølstad Poulsen
Author-X-Name-First: Niels Kjølstad
Author-X-Name-Last: Poulsen
Title: NNSYSID-Toolbox for System Identification with Neural Networks
Abstract:
The NNSYSID toolset for System Identification has been
developed as an add on to MATLAB®. The NNSYSID toolbox has been
designed to assist identification of nonlinear dynamic systems. It
contains a number of nonlinear model structures based on neural networks,
effective training algorithms and tools for model validation and model
structure selection. This paper gives an overview of the design of NNSYSID
and demonstrates its features in an example.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 1-20
Issue: 1
Volume: 8
Year: 2002
Month: 3
X-DOI: 10.1076/mcmd.8.1.1.8342
File-URL: http://hdl.handle.net/10.1076/mcmd.8.1.1.8342
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:1:p:1-20
Template-Type: ReDIF-Article 1.0
Author-Name: Drago Matko
Author-X-Name-First: Drago
Author-X-Name-Last: Matko
Author-Name: Gerhard Geiger
Author-X-Name-First: Gerhard
Author-X-Name-Last: Geiger
Title: Models of Pipelines in Transient Mode
Abstract:
The paper deals with the models for pipelines in transient
mode. The nonlinear distributed parameter model is first linearized and a
two input -- two output system is obtained. The models represented by
basic canonical equations are then rearranged into four feed-back models
(two hybrid, impedance and admittance) which are capable to describe the
oscillations phenomena. Transfer functions in the feed-back models are
transcendent with a time delay. Transcendent transfer functions are then
approximated with rational transfer functions. The derived models are
validated on a real pipeline data during start-up and shutdown phase of
the operation.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 117-136
Issue: 1
Volume: 8
Year: 2002
Month: 3
X-DOI: 10.1076/mcmd.8.1.117.8341
File-URL: http://hdl.handle.net/10.1076/mcmd.8.1.117.8341
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:1:p:117-136
Template-Type: ReDIF-Article 1.0
Author-Name: Ü. Kotta
Author-X-Name-First: Ü.
Author-X-Name-Last: Kotta
Author-Name: N. Sadegh
Author-X-Name-First: N.
Author-X-Name-Last: Sadegh
Title: Two Approaches for State Space Realization of NARMA Models: Bridging the Gap
Abstract:
This paper studies the necessary and sufficient conditions
for observable realization of a general class of nonlinear high-order
input-output difference equations. In particular, it proves the
equivalence of the two seemingly different existing approaches in the
literature. The paper also provides a subclass of NARMA input-output
models that are guaranteed to have an observable realization. It is shown
that this class covers several important subclasses of existing NARMA
models.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 21-32
Issue: 1
Volume: 8
Year: 2002
Month: 3
X-DOI: 10.1076/mcmd.8.1.21.8340
File-URL: http://hdl.handle.net/10.1076/mcmd.8.1.21.8340
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:1:p:21-32
Template-Type: ReDIF-Article 1.0
Author-Name: Mark A. Cusack
Author-X-Name-First: Mark A.
Author-X-Name-Last: Cusack
Title: Modelling Aggregate-Level Entities as a Continuum
Abstract:
We have modelled the movement of groups of entities over
realistic terrain using the equations of fluid dynamics. In our scheme,
individual vehicles, people and even natural phenomena are modelled as
localised packets of a fluid continuum that interact with a complex
environment. The approach preserves the character of the individual and at
the same time governs the long-range motion of the group. The scheme
supports the co-ordination of large numbers of entities in a low-cost and
plausible fashion. We provide details of how our technique has been
exploited to represent the progress of crowds of people, and discuss in
broad terms the scheme's general applicability to modelling aspects of
Operations Other Than War (OOTW). We also demonstrate how established
route planning techniques for single entities can be applied at the
aggregate level, to guide the progress of groups of entities along roads
and across open terrain.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 33-48
Issue: 1
Volume: 8
Year: 2002
Month: 3
X-DOI: 10.1076/mcmd.8.1.33.8339
File-URL: http://hdl.handle.net/10.1076/mcmd.8.1.33.8339
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:1:p:33-48
Template-Type: ReDIF-Article 1.0
Author-Name: V. CHANDRA
Author-X-Name-First: V.
Author-X-Name-Last: CHANDRA
Author-Name: R. Kumar
Author-X-Name-First: R.
Author-X-Name-Last: Kumar
Title: A Event Occurrence Rules based Compact Modeling Formalism for a Class of Discrete Event Systems
Abstract:
The analysis, failure diagnosis and control of discrete event
systems (DESs) requires an accurate model of the system. In this paper we
present a methodology which makes the task of modeling DESs considerably
less cumbersome, less error prone, and more user-friendly than it usually
is. In doing so we simplify the modeling formalism of [4, 5], proposed for
obtaining valid models of complex discrete event systems, by eliminating
‘precedence relations’, and capturing them as part of the
‘event occurrence rules’. Under the new modeling formalism
the size of the system model is polynomial in the number of signals;
whereas the number of states in the commonly used automata models is
exponential in the number of signals. We present automated techniques for
deriving an automaton model from the model in the proposed formalism. We
illustrate the modeling formalism using examples drawn from manufacturing
and process control systems.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 49-73
Issue: 1
Volume: 8
Year: 2002
Month: 3
X-DOI: 10.1076/mcmd.8.1.49.8338
File-URL: http://hdl.handle.net/10.1076/mcmd.8.1.49.8338
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:1:p:49-73
Template-Type: ReDIF-Article 1.0
Author-Name: K. Marti
Author-X-Name-First: K.
Author-X-Name-Last: Marti
Author-Name: A. Aurnhammer
Author-X-Name-First: A.
Author-X-Name-Last: Aurnhammer
Title: Robust Optimal Trajectory Planning for Robots by Stochastic Optimization
Abstract:
In the optimal control of industrial, field or service
robots, the standard procedure is to determine first offline a reference
trajectory and a feedforward control, based on some selected nominal
values of the unknown stochastic model parameters, and to correct then the
inevitable and increasing deviation of the state or performance of the
robot from the prescribed state or performance of the system by online
measurement and control actions. Due to the stochastic variations of the
model parameters, increasing measurement and correction actions are needed
during the process. By optimal stochastic trajectory planning (OSTP),
based on stochastic optimization methods, the available a priori and
sample information about the robot and its working environment is
incorporated into the control process. Consequently, more robust reference
trajectories and feedforward controls are obtained which cause much less
online control actions. In order to maintain a high quality of the guiding
functions, the reference trajectory and the feedforward control can be
updated at some later time points such that additional information about
the control process is available. After the presentation of the Adaptive
Optimal Stochastic Trajectory Planning (AOSTP) procedure based on
stochastic optimization methods, several numerical techniques for the
computation of robust reference trajectories and feedforward controls
under real-time conditions are presented. Additionally, numerical examples
for a Manutec r3 industrial robot are discussed. The first one
demonstrates real-time solutions of (OSTP) based on a sensitivity analysis
of a before-hand calculated reference trajectory. The second shows the
differences between reference trajectories based on deterministic methods
and the stochastic methods introduced in this paper. Based on simulations
of the robots behavior, the increased robustness of stochastic reference
trajectories is demonstrated.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 75-116
Issue: 1
Volume: 8
Year: 2002
Month: 3
X-DOI: 10.1076/mcmd.8.1.75.8343
File-URL: http://hdl.handle.net/10.1076/mcmd.8.1.75.8343
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:1:p:75-116
Template-Type: ReDIF-Article 1.0
Author-Name: J. McPhee
Author-X-Name-First: J.
Author-X-Name-Last: McPhee
Author-Name: P. Shi
Author-X-Name-First: P.
Author-X-Name-Last: Shi
Author-Name: J.-C. Piedbuf
Author-X-Name-First: J.-C.
Author-X-Name-Last: Piedbuf
Title: Dynamics of Multibody Systems Using Virtual Work and Symbolic Programming
Abstract:
Two different Maple programs have been developed to generate
automatically the symbolic kinematic and dynamic equations for rigid and
flexible multibody systems, given only a description of the system as
input. Kinematic equations are generated using graph-theoretic methods in
one program, and by a recursive formulation in the second. Virtual work
and virtual power methods are used to develop the dynamic equations in
terms of joint coordinates. These dynamic equations are reduced to a
minimal set, i.e., one equation per system degree of freedom, by using an
orthogonal complement based on partitioning of virtual displacements or
speeds. The symbolic dynamic equations are easily solved for the actuator
loads in an inverse dynamic analysis, especially if the actuated joint
coordinates are selected as independent variables. This orthogonal
complement approach also offers certain advantages for the forward dynamic
simulation of rigid and flexible systems; these advantages are outlined in
the first example. In the second example, the inverse dynamics problem is
solved for the Gough-Stewart platform, a complex example of a parallel
manipulator, and compared to previous results in the literature.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 137-155
Issue: 2
Volume: 8
Year: 2002
Month: 6
X-DOI: 10.1076/mcmd.8.2.137.8591
File-URL: http://hdl.handle.net/10.1076/mcmd.8.2.137.8591
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:2:p:137-155
Template-Type: ReDIF-Article 1.0
Author-Name: L. Bascetta
Author-X-Name-First: L.
Author-X-Name-Last: Bascetta
Author-Name: P. Rocco
Author-X-Name-First: P.
Author-X-Name-Last: Rocco
Title: Modelling Flexible Manipulators With Motors at the Joints
Abstract:
A computationally efficient recursive model of a flexible
manipulator with motors at the joints is described in this paper. The
model adopts a mixed Eulerian and Lagrangian formulation of the equations
of a flexible body and exploits the chained structure of the equations for
a serial manipulator. The dynamic effects of the motors at the joints,
including gyroscopic terms, are fully taken into account. Symbolic
manipulation is used in a newly developed package, whose performance in
detailed reproduction of the dynamic effects due to the interplay between
the motors and the flexible links is assessed through simulation. A
comparison between the complete model and a simplified one, where the
motors are considered as simple inertias rotating around their own axis,
has been carried out, using both a time domain analysis and a frequency
domain analysis, in order to show the relevance of gyroscopic effects in
modelling flexible robots.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 157-183
Issue: 2
Volume: 8
Year: 2002
Month: 6
X-DOI: 10.1076/mcmd.8.2.157.8593
File-URL: http://hdl.handle.net/10.1076/mcmd.8.2.157.8593
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:2:p:157-183
Template-Type: ReDIF-Article 1.0
Author-Name: M. Ö. Eff
Author-X-Name-First: M. Ö.
Author-X-Name-Last: Eff
Author-Name: O. Kaynak
Author-X-Name-First: O.
Author-X-Name-Last: Kaynak
Author-Name: B. M. Wilamowski
Author-X-Name-First: B. M.
Author-X-Name-Last: Wilamowski
Title: A Robust Identification Technique for Time-Varying ARMA Processes Based on Variable Structure Systems Theory
Abstract:
In this paper, a novel method for extracting the values of
the coefficients of time-varying ARMA processes is proposed. The approach
discussed assumes solely that the orders of the numerator and the
denominator polynomials are known. The algorithm is demonstrated to be
stable in the sense of Lyapunov, furthermore, it is shown in the paper
that the evolution in the parameter space takes place in a finite volume.
The proposed method is cost effective and is based on the variable
structure systems theory, which is well known with its robustness to
uncertainties. In the simulation example, the coefficients of a second
order ARMA process is extracted by the use of the algorithm presented. The
results confirm the prominent features of the proposed technique.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 185-198
Issue: 2
Volume: 8
Year: 2002
Month: 6
X-DOI: 10.1076/mcmd.8.2.185.8592
File-URL: http://hdl.handle.net/10.1076/mcmd.8.2.185.8592
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:2:p:185-198
Template-Type: ReDIF-Article 1.0
Author-Name: Hamed Nassar
Author-X-Name-First: Hamed
Author-X-Name-Last: Nassar
Author-Name: Hassan Al Mahdy
Author-X-Name-First: Hassan Al
Author-X-Name-Last: Mahdy
Title: A Priority Discrete Queueing Model for Multimedia Multiplexers
Abstract:
Multiplexers have been extensively modeled as discrete time
queueing systems. In this article, we model a multimedia multiplexer
handling traffic of two classes. One class represents real-time traffic,
e.g., packets of live audio or video transmissions, and the other
nonreal-time traffic, e.g., packets of file transfer transmissions. These
packets arrive into the multiplexer in batches. In each time slot, one
batch of each class arrive. The multiplexer gives service priority to
class-1 packets over class-2. The demands of each class are in conflict
with that of the other, and thus they are treated by the multiplexer
differently. The multiplexer is thus modeled as a (preemptive) priority
discrete queueing system with simultaneous batch arrivals and geometric
service time. The system occupancy is analyzed and the joint probability
generating function (PGF) of the number of packets of each class is
derived. From this PGF, marginal PGFs of interest are obtained. The
results for deterministic service time, most suitable for ATM purposes,
are readily obtainable as a special case from the results of this article.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 199-211
Issue: 2
Volume: 8
Year: 2002
Month: 6
X-DOI: 10.1076/mcmd.8.2.199.8590
File-URL: http://hdl.handle.net/10.1076/mcmd.8.2.199.8590
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:2:p:199-211
Template-Type: ReDIF-Article 1.0
Author-Name: S. Chiaverini
Author-X-Name-First: S.
Author-X-Name-Last: Chiaverini
Author-Name: G. Fusco
Author-X-Name-First: G.
Author-X-Name-Last: Fusco
Title: The Use of Real-World Computer Models for Computer-Aided Design of Tracking Control Schemes for Induction Motors
Abstract:
The design of tracking controllers for induction motors is
usually developed by neglecting the presence of power-supply devices, such
as inverters, and measurement apparatuses, e.g., encoders. However, these
components represent unmodeled dynamics that are present during the real
operating conditions of the induction motor. Since the development of a
numerical simulation study represents a low-cost, safe, and fast test to
validate the design of tracking control schemes, the need arises to build
a computer model of the overall system (i.e., motor, power supply,
measurement devices, and tracking controller) as realistic as possible. In
this context, the paper describes a computer model for simulation of an
induction motor under a tracking control scheme including many real-world
effects; namely, encoder's quantization, current sensors' noise, stator
current dynamics, presence of a current-controlled voltage-source inverter
within a stator current regulator loop, flux observer dynamics, saturation
of the control signal, and discrete-time implementation of the control
algorithm. The developed computer model is finally used in a case study
and the simulation results obtained for an induction motor driving a
single-link robotic arm under an H8 tracking control scheme are reported.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 213-233
Issue: 2
Volume: 8
Year: 2002
Month: 6
X-DOI: 10.1076/mcmd.8.2.213.8589
File-URL: http://hdl.handle.net/10.1076/mcmd.8.2.213.8589
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:2:p:213-233
Template-Type: ReDIF-Article 1.0
Author-Name: M. Dinkelmann
Author-X-Name-First: M.
Author-X-Name-Last: Dinkelmann
Author-Name: M. Wächter
Author-X-Name-First: M.
Author-X-Name-Last: Wächter
Author-Name: G. Sachs
Author-X-Name-First: G.
Author-X-Name-Last: Sachs
Title: Modelling of Heat Transfer and Vehicle Dynamics for Thermal Load Reduction by Hypersonic Flight Optimization
Abstract:
Heat input reduction by appropriate, optimal trajectory
control is considered for the range cruise and the return-to-base cruise
of a hypersonic vehicle propelled by a turbo/ram jet engines combination.
A mathematical model is developed for describing the unsteady heat
transfer through the thermal protection system. This model is coupled to
the model of the dynamics of the vehicle. An efficient optimization
technique is applied for constructing a solution for the two cruise
problems. The results show that significant heat input reductions can be
achieved with only a small penalty in fuel consumption.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 237-255
Issue: 3
Volume: 8
Year: 2002
Month: 9
X-DOI: 10.1076/mcmd.8.3.237.14098
File-URL: http://hdl.handle.net/10.1076/mcmd.8.3.237.14098
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:3:p:237-255
Template-Type: ReDIF-Article 1.0
Author-Name: N. Bairagi
Author-X-Name-First: N.
Author-X-Name-Last: Bairagi
Author-Name: J. Chattopadhyay
Author-X-Name-First: J.
Author-X-Name-Last: Chattopadhyay
Title: Pelican at Risk in Salton Sea -- a Delay-Induced Eco-Epidemiological Model
Abstract:
Elevated salinity, accelerated eutrophication, blooms of
Avian botulism and dramatic water quality fluctuation are supposed to be
the key factors for massive die-off of Tilapia (prey) and Pelican
(predator) in the Salton sea. We modify the model of Chattopadhyay and
Bairagi [Ecological Modelling 136 (2001), pp. 103-112] with an assumption
that the growth rate of susceptible fish population is very high and study
the dynamics of the system by introducing a delay factor in the predator
response function. It is observed that the otherwise stable system exhibit
a stable limit cycle solution when the lag factor attains its critical
value. It is also observed that there is a high possibility of an epidemic
out break in the fish as well as in the Pelican population if the
predation process is delayed by a considerable amount of time. Numerical
simulations for a hypothetical set of parameter values are presented to
illustrate the analytical findings.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 257-272
Issue: 3
Volume: 8
Year: 2002
Month: 9
X-DOI: 10.1076/mcmd.8.3.257.14101
File-URL: http://hdl.handle.net/10.1076/mcmd.8.3.257.14101
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:3:p:257-272
Template-Type: ReDIF-Article 1.0
Author-Name: Y.H. Zweiri
Author-X-Name-First: Y.H.
Author-X-Name-Last: Zweiri
Author-Name: J.F. Whidborne
Author-X-Name-First: J.F.
Author-X-Name-Last: Whidborne
Author-Name: L.D. Seneviratne
Author-X-Name-First: L.D.
Author-X-Name-Last: Seneviratne
Author-Name: K. Althoefer
Author-X-Name-First: K.
Author-X-Name-Last: Althoefer
Title: A Comparison of Dynamic Models of Various Complexity for Diesel Engines
Abstract:
Diesel engines are widely used in many application domains.
The recent drive to reduce emissions, improve efficiency and implement on
board diagnostic tools has resulted in a real need for improved models for
the simulation of Diesel engines. This paper evaluates three different
Diesel engine dynamic models of varying levels of complexity. The
assumptions for the models and the equations are presented. The equations
are implemented in a computer simulation environment. The models describe
the dynamic relationship between indicated pressure and engine speed. The
first model is a detailed analytical non-linear dynamic model, including
dynamometer dynamics, instantaneous friction components, viscosity
variations with temperature and inertia variations with piston pin offset.
In-cycle calculations are performed at each crank-angle. The second model
is a nonlinear dynamic model which includes a mean friction model for the
engine components and dynamometer dynamics, but does not include the
piston pin offset as well as the inertia variations. The third model is
obtained by an identification procedure to find a low-order linear
transfer function between the engine input and output. The three models
are used to predict the behaviour of a Diesel engine. The models are
compared using experimentally measured engine speeds, under steady state
and transient operating conditions. The paper discusses the suitability of
the models for various control applications such as engine simulation,
fuelling control system design and fault diagnostics.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 273-289
Issue: 3
Volume: 8
Year: 2002
Month: 9
X-DOI: 10.1076/mcmd.8.3.273.14100
File-URL: http://hdl.handle.net/10.1076/mcmd.8.3.273.14100
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:3:p:273-289
Template-Type: ReDIF-Article 1.0
Author-Name: P.F. Weston
Author-X-Name-First: P.F.
Author-X-Name-Last: Weston
Author-Name: J.P. Norton
Author-X-Name-First: J.P.
Author-X-Name-Last: Norton
Title: Graded Set-Membership Models
Abstract:
The values of the parameters or state variables of a
set-membership model are classified only as feasible (consistent with the
observations and with specified bounds on output error and unknown
forcing) or not. Such classification is compatible with worst-case design
or prediction, but uninformative about the average quality of fit to the
observations. Also, it neglects any distributional information which may
be available. The paper addresses the problem of grading the feasible set,
according to how well each feasible value matches the data or whether it
meets simple requirements on distribution. Computing load and
approximation are considered.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 291-305
Issue: 3
Volume: 8
Year: 2002
Month: 9
X-DOI: 10.1076/mcmd.8.3.291.14096
File-URL: http://hdl.handle.net/10.1076/mcmd.8.3.291.14096
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:3:p:291-305
Template-Type: ReDIF-Article 1.0
Author-Name: P.R. Drake
Author-X-Name-First: P.R.
Author-X-Name-Last: Drake
Author-Name: K.A. Miller
Author-X-Name-First: K.A.
Author-X-Name-Last: Miller
Title: Improved Self-Feedback Gain in the Context Layer of a Modified Elman Neural Network
Abstract:
The use of a range of values for the self-feedback gains in
the context layer of a modified Elman neural network is shown to reduce
RMS error when modelling a non-linear dynamic system.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 307-311
Issue: 3
Volume: 8
Year: 2002
Month: 9
X-DOI: 10.1076/mcmd.8.3.307.14099
File-URL: http://hdl.handle.net/10.1076/mcmd.8.3.307.14099
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:3:p:307-311
Template-Type: ReDIF-Article 1.0
Author-Name: R. Lotto
Author-X-Name-First: R.
Author-X-Name-Last: Lotto
Author-Name: A. Ferrara
Author-X-Name-First: A.
Author-X-Name-Last: Ferrara
Title: A Transportation Network Model as a Tool to Solve Urban Planning Location Problems
Abstract:
The aim of this paper is to formulate a transportation
network model conceived as a basis of possible tools to be used by
administrators and planners to approach location problems in a urban
context. The key element of this model is a static representation of the
transportation network, made of oriented links and nodes, connecting the
facilities located in a prespecified urban area. Such a representation is
based on an analogy of electric nature, thus allowing to exploit
conventional electric networks solvers to determine the relevant features
of the traffic flow in each link of the transportation network. The
facility quality level is also taken into account in a quantitative
fashion. Relying on the proposed model, different related results, such as
the minimum path matrix and the induced traffic in each link of the
network can be retrieved.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 313-332
Issue: 3
Volume: 8
Year: 2002
Month: 9
X-DOI: 10.1076/mcmd.8.3.313.14095
File-URL: http://hdl.handle.net/10.1076/mcmd.8.3.313.14095
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:3:p:313-332
Template-Type: ReDIF-Article 1.0
Author-Name: M.M. Gouda
Author-X-Name-First: M.M.
Author-X-Name-Last: Gouda
Author-Name: S. Danaher
Author-X-Name-First: S.
Author-X-Name-Last: Danaher
Author-Name: C.P. Underwood
Author-X-Name-First: C.P.
Author-X-Name-Last: Underwood
Title: Application of an Artificial Neural Network for Modelling the Thermal Dynamics of a Building’s Space and its Heating System
Abstract:
Artificial neural networks (ANNs) have been used for
modelling the thermal dynamics of a building’s space, its water
heating system and the influence of solar radiation. A multi-layer
feed-forward neural network, using a Levenberg-Marquardt
backpropagation-training algorithm, has been applied to predict the future
internal temperature. Real weather data for a number of winter months,
together with a validated building model (based on the building
constructions data), were used to train the network in order to generate a
mapping between the easily measurable inputs (outdoor temperature, solar
irradiance, heating valve position and the building indoor temperature)
and the desired output, i.e., the predicted indoor temperature. The
objective of this work was to investigate the potential of using an ANN
with singular value decomposition method (SVD) to predict the indoor
temperature to shut down the heating system controller early for saving
the energy consumption for heating inside the building.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 333-344
Issue: 3
Volume: 8
Year: 2002
Month: 9
X-DOI: 10.1076/mcmd.8.3.333.14097
File-URL: http://hdl.handle.net/10.1076/mcmd.8.3.333.14097
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:3:p:333-344
Template-Type: ReDIF-Article 1.0
Author-Name: P. Rapisarda
Author-X-Name-First: P.
Author-X-Name-Last: Rapisarda
Author-Name: H.L. Trentelman
Author-X-Name-First: H.L.
Author-X-Name-Last: Trentelman
Title: The Behavioral Approach to Systems and Modeling
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 347-359
Issue: 4
Volume: 8
Year: 2002
Month: 12
X-DOI: 10.1076/mcmd.8.4.347.15852
File-URL: http://hdl.handle.net/10.1076/mcmd.8.4.347.15852
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:4:p:347-359
Template-Type: ReDIF-Article 1.0
Author-Name: TOMMASO COTRONEO
Author-X-Name-First: TOMMASO
Author-X-Name-Last: COTRONEO
Author-Name: JACOB DIJK
Author-X-Name-First: JACOB
Author-X-Name-Last: DIJK
Title: Modeling With the Behavioral Toolbox
Abstract:
In this paper we describe the main features of the Behavioral
Toolbox for modeling of dynamical systems. The Toolbox, recently developed
at the University of Groningen, implements the ideas on modeling which are
at the heart of behavioral systems theory. In particular, it does not rely
on predefined input/output descriptions and thus allows great flexibility
in defining interconnections between systems. By means of an example we
show how the different phases of a modeling and simulation session can be
tackled within the framework provided by the Behavioral Toolbox.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 361-376
Issue: 4
Volume: 8
Year: 2002
Month: 12
X-DOI: 10.1076/mcmd.8.4.361.15847
File-URL: http://hdl.handle.net/10.1076/mcmd.8.4.361.15847
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:4:p:361-376
Template-Type: ReDIF-Article 1.0
Author-Name: Kiyotsugu Takaba
Author-X-Name-First: Kiyotsugu
Author-X-Name-Last: Takaba
Author-Name: Yutaka Ichihara
Author-X-Name-First: Yutaka
Author-X-Name-Last: Ichihara
Title: Interconnections and Initial Conditions of Linear Systems With First-Order Representations
Abstract:
This paper considers the initial value problem of an
interconnection composed of linear systems described by the first-order
differential/algebraic equations (DAEs). An initial condition of the
system variable for which the DAE has a solution is called admissible. For
the interconnected system, we formulate the invariance of the admissible
initial condition sets (AICSs) of the sub-systems under interconnection.
Namely, the AICSs are said to be invariant if they remain unchanged even
when additional constraints due to interconnection are imposed on the
system variables. It is shown that the feedback and regular feedback
structures of the interconnection guarantee the invariance of the AICSs in
the senses of impulsive-smooth distributions and smooth distributions,
respectively. The results in this paper justify the use of a feedback
controller in the control system design.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 377-396
Issue: 4
Volume: 8
Year: 2002
Month: 12
X-DOI: 10.1076/mcmd.8.4.377.15851
File-URL: http://hdl.handle.net/10.1076/mcmd.8.4.377.15851
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:4:p:377-396
Template-Type: ReDIF-Article 1.0
Author-Name: Shiva Shankar
Author-X-Name-First: Shiva
Author-X-Name-Last: Shankar
Title: The Evolution of the Concept of Controllability
Abstract:
This paper traces the evolution of the central concept of
controllability of state space systems introduced by Kalman to its
behavioural generalisation byWillems, and beyond to distributed
behaviours. It turns out that controllability in this new formalism is
identical to the notion of a potential in physics or of exactness in
mathematics.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 397-406
Issue: 4
Volume: 8
Year: 2002
Month: 12
X-DOI: 10.1076/mcmd.8.4.397.15845
File-URL: http://hdl.handle.net/10.1076/mcmd.8.4.397.15845
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:4:p:397-406
Template-Type: ReDIF-Article 1.0
Author-Name: Madhu N. Belur
Author-X-Name-First: Madhu N.
Author-X-Name-Last: Belur
Author-Name: Harry L. Trentelman
Author-X-Name-First: Harry L.
Author-X-Name-Last: Trentelman
Title: Algorithmic Issues in the Synthesis of Dissipative Systems
Abstract:
In this paper we discuss algorithmic issues that arise in the
problem of synthesis of dissipative systems. We deal with linear
differential systems that can be controlled only through a restricted set
of variables called the control variables. The main feature of this paper
is that we assume the system dynamics to be specified in the most general
form: a latent variable representation. Starting from such a
representation, we provide concrete algorithms that finally fetch a
controller to implement the desired behavior. Many other peripheral
algorithmic issues that crop up are also studied.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 407-428
Issue: 4
Volume: 8
Year: 2002
Month: 12
X-DOI: 10.1076/mcmd.8.4.407.15848
File-URL: http://hdl.handle.net/10.1076/mcmd.8.4.407.15848
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:4:p:407-428
Template-Type: ReDIF-Article 1.0
Author-Name: Margreta Kuijper
Author-X-Name-First: Margreta
Author-X-Name-Last: Kuijper
Author-Name: Jan Willem Polderman
Author-X-Name-First: Jan Willem
Author-X-Name-Last: Polderman
Title: Behavioral Models for List Decoding
Abstract:
Recently it has been shown that list decoding of Reed-Solomon
codes may be translated into a bivariate interpolation problem. The data
consist of pairs in a finite field and the aim is to find a bivariate
polynomial that interpolates the given pairs and is minimal with respect
to some criterion. We present a systems theoretic approach to this
interpolation problem. With the data points we associate a set of time
series, also called trajectories. For this set of trajectories we
construct the Most Powerful Unfalsified Model (MPUM). This is the smallest
possible model that explains these trajectories. The bivariate polynomial
is then derived from a specific polynomial representation of the MPUM.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 429-443
Issue: 4
Volume: 8
Year: 2002
Month: 12
X-DOI: 10.1076/mcmd.8.4.429.15849
File-URL: http://hdl.handle.net/10.1076/mcmd.8.4.429.15849
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:4:p:429-443
Template-Type: ReDIF-Article 1.0
Author-Name: A.J. Mayo
Author-X-Name-First: A.J.
Author-X-Name-Last: Mayo
Author-Name: A.C. Antoulas
Author-X-Name-First: A.C.
Author-X-Name-Last: Antoulas
Title: A Behavioural Approach to Positive Real Interpolation
Abstract:
We study interpolation by positive real functions from a
behavioural point of view. In particular, by considering the notion of
mirror image data, the interpolation problem with passivity constraint is
transformed into an unconstrained behavioural modeling one. The main
conclusion is that the generating system for this problem has to be
unitary with respect to an indefinite matrix. In addition we investigate
the multiple-point positive real interpolation problem. This leads to a
solution of the positive real realization problem where the data are
Markov parameters.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 445-455
Issue: 4
Volume: 8
Year: 2002
Month: 12
X-DOI: 10.1076/mcmd.8.4.445.15846
File-URL: http://hdl.handle.net/10.1076/mcmd.8.4.445.15846
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:4:p:445-455
Template-Type: ReDIF-Article 1.0
Author-Name: P. Rapisarda
Author-X-Name-First: P.
Author-X-Name-Last: Rapisarda
Author-Name: H.L. Trentelman
Author-X-Name-First: H.L.
Author-X-Name-Last: Trentelman
Title: Hamiltonian and Variational Linear Distributed Systems
Abstract:
We use the formalism of bilinear- and quadratic differential
forms in order to study Hamiltonian and variational linear distributed
systems. It was shown in [1] that a system described by ordinary linear
constant-coefficient differential equations is Hamiltonian if and only if
it is variational. In this paper we extend this result to systems
described by linear, constant-coefficient partial differential equations.
It is shown that any variational system is Hamiltonian, and that any
scalar Hamiltonian system is contained (in general, properly) in a
particular variational system.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 457-473
Issue: 4
Volume: 8
Year: 2002
Month: 12
X-DOI: 10.1076/mcmd.8.4.457.15850
File-URL: http://hdl.handle.net/10.1076/mcmd.8.4.457.15850
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Handle: RePEc:taf:nmcmxx:v:8:y:2002:i:4:p:457-473
Template-Type: ReDIF-Article 1.0
Author-Name: Sung Je Kim
Author-X-Name-First: Sung Je
Author-X-Name-Last: Kim
Author-Name: Young Man Cho
Author-X-Name-First: Young Man
Author-X-Name-Last: Cho
Title: Design-tool for Rapid Thermal Processors for Optimal Trajectory Tracking
Abstract:
It has become an irreversible trend in recent years that the
semiconductor wafer fabrication requires shorter processing time, greater
flexibility and lower capital cost. Rapid thermal processing (RTP) has
demonstrated its potential to meet such requirements while becoming a key
process for manufacturing advanced semiconductor devices. Ever decreasing
feature sizes require extremely tightly controlled processing conditions,
especially the temperature trajectory to be precisely followed across the
wafer. This paper presents a systematic methodology for RTP chamber
design, based on the 3-dimensional physics-based model of a generic RTP
chamber. After experimentally validated, the physics-based model is
reduced to a lower-order model without sacrificing its fidelity for
computational efficiency. With a reduced-order model, optimization studies
are performed to determine how small the deviation of the wafer
temperature from the pre-specified trajectory can be made in a given
design. The results of the optimization studies indicate the goodness of
the given RTP design, unravel clues for design improvements, and may
provide guidelines for control implementation.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 1-24
Issue: 1
Volume: 9
Year: 2003
Month: 3
X-DOI: 10.1076/mcmd.9.1.1.16514
File-URL: http://hdl.handle.net/10.1076/mcmd.9.1.1.16514
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Handle: RePEc:taf:nmcmxx:v:9:y:2003:i:1:p:1-24
Template-Type: ReDIF-Article 1.0
Author-Name: A. Bartel
Author-X-Name-First: A.
Author-X-Name-Last: Bartel
Author-Name: M. Günther
Author-X-Name-First: M.
Author-X-Name-Last: Günther
Title: From SOI to Abstract Electric-Thermal-1D Multiscale Modeling for First Order Thermal Effects
Abstract:
Self-heating occurs in integrated circuits, specially for
SOI-based devices. Naturally, the heat distribution affects the
circuit’s functionality. For reliable designs in SOI-chip
technology, and other applications, the thermal aspects have to be
addressed. Therefore we develop a model, which is based on distributed 1D
and lumped 0D elements, and takes into account that heat is stored and
slowly conducted between elements. The emerging coupled multiscale system
of heat evolution and electric network consists of parabolic
partial-differential (thermal part) and differential-algebraic equations
(electric network part). For the thermal model, we verify properties as
positivity and strict passivity. Since time scales differ largely, the
coupled problem exhibits multirate potential.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 25-44
Issue: 1
Volume: 9
Year: 2003
Month: 3
X-DOI: 10.1076/mcmd.9.1.25.16517
File-URL: http://hdl.handle.net/10.1076/mcmd.9.1.25.16517
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:9:y:2003:i:1:p:25-44
Template-Type: ReDIF-Article 1.0
Author-Name: B.C. Fabien
Author-X-Name-First: B.C.
Author-X-Name-Last: Fabien
Author-Name: M. Ramulu
Author-X-Name-First: M.
Author-X-Name-Last: Ramulu
Author-Name: M. Tremblay
Author-X-Name-First: M.
Author-X-Name-Last: Tremblay
Title: Dynamic Modelling and Identification of a Waterjet Cutting System
Abstract:
This paper describes a new dynamic model for a waterjet
cutting system that includes a double-acting reciprocating intensifier
pump. Since the system operates at high pressures the fluid flow is
assumed to be compressible. The dynamic model includes the characteristics
of the intensifier pump, the check valves, the accumulator, the system
piping and compressible jet flow through the nozzle. The system model is
presented as a set of differential-algebraic equations. Experimental
results for an actual system are used to identify the discharge
coefficient of the nozzle, certain unknown parameters associated with the
check valve, and to determine the velocity profile of the piston in the
intensifier pump. This is accomplished by formulating and solving a
parameter optimization problem. The paper also includes numerical
simulation results that validate the dynamic model.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 45-63
Issue: 1
Volume: 9
Year: 2003
Month: 3
X-DOI: 10.1076/mcmd.9.1.45.16513
File-URL: http://hdl.handle.net/10.1076/mcmd.9.1.45.16513
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Handle: RePEc:taf:nmcmxx:v:9:y:2003:i:1:p:45-63
Template-Type: ReDIF-Article 1.0
Author-Name: A. Urquia
Author-X-Name-First: A.
Author-X-Name-Last: Urquia
Author-Name: S. Dormido
Author-X-Name-First: S.
Author-X-Name-Last: Dormido
Title: Object-oriented Design of Reusable Model Libraries of Hybrid Dynamic Systems -- Part One: A Design Methodology
Abstract:
An object-oriented methodology for the design of reusable
model libraries, dedicated to the composition of hybrid simulation models,
is proposed. It takes into consideration all the phases of the library
life cycle: design, programming, maintenance, modifications, extension,
etc. The methodology distinguishes between the role of the library
designers and the role of the library users. One of its main goals is
guaranteeing that the users are able to use the libraries without having
to know their internal details. In particular, users should not be
confronted with numerical problems. The library designers should guarantee
the numerical efficiency of the models based on the library
predefined-models. In this respect, some of the numerical aspects of the
model library design are discussed. The concept of library design rules is
introduced as the cornerstone of the proposed methodology.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 65-90
Issue: 1
Volume: 9
Year: 2003
Month: 3
X-DOI: 10.1076/mcmd.9.1.65.16516
File-URL: http://hdl.handle.net/10.1076/mcmd.9.1.65.16516
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:9:y:2003:i:1:p:65-90
Template-Type: ReDIF-Article 1.0
Author-Name: A. Urquia
Author-X-Name-First: A.
Author-X-Name-Last: Urquia
Author-Name: S. Dormido
Author-X-Name-First: S.
Author-X-Name-Last: Dormido
Title: Object-oriented Design of Reusable Model Libraries of Hybrid Dynamic Systems -- Part Two: A Case Study
Abstract:
A novel object-oriented methodology for the design of model
libraries is exemplified by means of the design of JARA. JARA is a set of
libraries of dynamic hybrid models of some fundamental physical-chemical
principles. Its main application field is the modeling of
physical-chemical processes in the context of automatic control. Only a
reduced set of phenomena has been selected for modeling, focusing mainly
on illustrating relevant aspects of the proposed design methodology. The
five steps of the design methodology are followed and the design rules of
JARA are obtained.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 91-118
Issue: 1
Volume: 9
Year: 2003
Month: 3
X-DOI: 10.1076/mcmd.9.1.91.16515
File-URL: http://hdl.handle.net/10.1076/mcmd.9.1.91.16515
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Handle: RePEc:taf:nmcmxx:v:9:y:2003:i:1:p:91-118
Template-Type: ReDIF-Article 1.0
Author-Name: M. Carrillo
Author-X-Name-First: M.
Author-X-Name-Last: Carrillo
Title: Growth, Life Cycle and Dynamic Modelling
Abstract:
Growth and diffusion processes have received great interest
from investigators in many disciplines, such as Biology, Demography or
Economics. These processes are usually analyzed by means of sigmoidal
curves that formalize the well-known theory of the life cycle. The
characteristic stages in the biological life cycle of an organism are
widely applicable to technology progress, sales of a new product or the
evolution of economic sectors. In this paper a mathematical
characterization of sigmoidal growth is presented that gives rise to a
general methodology for modelling such processes, additionally allowing to
establish a qualitative equivalence among sigmoidal growth-type phenomena.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 121-136
Issue: 2
Volume: 9
Year: 2003
Month: 6
X-DOI: 10.1076/mcmd.9.2.121.16518
File-URL: http://hdl.handle.net/10.1076/mcmd.9.2.121.16518
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Handle: RePEc:taf:nmcmxx:v:9:y:2003:i:2:p:121-136
Template-Type: ReDIF-Article 1.0
Author-Name: G. Klancar
Author-X-Name-First: G.
Author-X-Name-Last: Klancar
Author-Name: M. Lepetic
Author-X-Name-First: M.
Author-X-Name-Last: Lepetic
Author-Name: R. Karba
Author-X-Name-First: R.
Author-X-Name-Last: Karba
Author-Name: B. Zupancic
Author-X-Name-First: B.
Author-X-Name-Last: Zupancic
Title: Robot Soccer Collision Modelling and Validation in Multi-Agent Simulator
Abstract:
The paper deals with mathematical modelling and simulation of
collisions in robot soccer representing ideal playground for studying
multi-agent mobile systems. It involves robot and ball dynamic behaviour
and focuses mainly on their collisions study and their realization. Some
vital parts of the simulator are explained and modelled in more detail,
beginning with the simple model of ball and robot motion and continuing
with more complex collision models. Special consideration is given to
collision between robots. The design of such model takes two steps. In the
first, information about possible collision is obtained. The second step
realizes collision by determining appropriate force impulse. The results
from model verification are presented. It is shown that the developed
model represents a good basis for realistic, yet simple enough, collision
simulation. The paper concludes with some remarks and ideas for future
work.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 137-150
Issue: 2
Volume: 9
Year: 2003
Month: 6
X-DOI: 10.1076/mcmd.9.2.137.16523
File-URL: http://hdl.handle.net/10.1076/mcmd.9.2.137.16523
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Handle: RePEc:taf:nmcmxx:v:9:y:2003:i:2:p:137-150
Template-Type: ReDIF-Article 1.0
Author-Name: H. Fibrianto
Author-X-Name-First: H.
Author-X-Name-Last: Fibrianto
Author-Name: L. Boillereaux
Author-X-Name-First: L.
Author-X-Name-Last: Boillereaux
Author-Name: J.M. Flaus
Author-X-Name-First: J.M.
Author-X-Name-Last: Flaus
Title: Internal Dynamics Stability of a Heat Conduction System Reduced via Orthogonal Collocation
Abstract:
This paper deals with the crucial problem of choice of the
collocation points in the reduction of a one-dimensional heat transfer
problem into an ordinary differential equation system. It is shown that,
for its parabolic differential equation, the use of such an approach can
either lead to systems with or without a NMP behaviour, which is not
characteristic of the original behaviour of the initial system. A simple
rule of choice, restrained to this class of systems, is given to avoid
this phenomenon.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 151-164
Issue: 2
Volume: 9
Year: 2003
Month: 6
X-DOI: 10.1076/mcmd.9.2.151.16522
File-URL: http://hdl.handle.net/10.1076/mcmd.9.2.151.16522
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Handle: RePEc:taf:nmcmxx:v:9:y:2003:i:2:p:151-164
Template-Type: ReDIF-Article 1.0
Author-Name: Sangbum Cho
Author-X-Name-First: Sangbum
Author-X-Name-Last: Cho
Author-Name: Jinglai Shen
Author-X-Name-First: Jinglai
Author-X-Name-Last: Shen
Author-Name: N. Harris Mcclamroch
Author-X-Name-First: N. Harris
Author-X-Name-Last: Mcclamroch
Title: Mathematical Models for the Triaxial Attitude Control Testbed
Abstract:
The Triaxial Attitude Control Testbed has been developed as
part of a research program at the University of Michigan on multibody
rotational dynamics and control. In this paper, equations of motion are
derived and presented in various forms. Actuation mechanisms are
incorporated into the models; these include fan actuators, reaction wheel
actuators and proof mass actuators that are fixed to the triaxial base
body. The models also allow incorporation of unactuated auxiliary bodies
that are constrained to move relative to the triaxial base body. The
models expose the dynamic coupling between the rotational motion of the
triaxial base body, the relative or shape motion of the unactuated
auxiliary degrees of freedom, and dynamics associated with actuation
mechanisms. Many different model simplifications and approximations are
developed. Control models for the triaxial attitude control testbed are
formulated that reflect specific assumptions.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 165-192
Issue: 2
Volume: 9
Year: 2003
Month: 6
X-DOI: 10.1076/mcmd.9.2.165.16520
File-URL: http://hdl.handle.net/10.1076/mcmd.9.2.165.16520
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Handle: RePEc:taf:nmcmxx:v:9:y:2003:i:2:p:165-192
Template-Type: ReDIF-Article 1.0
Author-Name: Jin-Oh Hahn
Author-X-Name-First: Jin-Oh
Author-X-Name-Last: Hahn
Author-Name: Jae-Woong Hur
Author-X-Name-First: Jae-Woong
Author-X-Name-Last: Hur
Author-Name: Young Man Cho
Author-X-Name-First: Young Man
Author-X-Name-Last: Cho
Author-Name: Kyo Ii Lee
Author-X-Name-First: Kyo Ii
Author-X-Name-Last: Lee
Title: Empirical Modeling of a Hydraulic Actuator in a Vehicle Control System
Abstract:
The pressure information of a hydraulic actuator plays a key
role in modern vehicle control and fault diagnosis. The difficulty in
measuring pressure directly naturally motivates such an indirect approach
as an observer whose accuracy depends heavily upon the availability of a
high fidelity model of a hydraulic actuator. Notwithstanding its success
in understanding the dynamics of the first principle model of a hydraulic
actuator, it is not suited to controller/observer design due to its
complexity. This paper presents an alternative to the first principle
modeling methodology: an empirical approach to hydraulic actuator
modeling. Linear and nonlinear system identification techniques are
applied to obtain low-order models of a hydraulic actuator. Experimental
results show how the empirical models reproduce the key features of a
hydraulic actuator with sufficient accuracy.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 193-208
Issue: 2
Volume: 9
Year: 2003
Month: 6
X-DOI: 10.1076/mcmd.9.2.193.16519
File-URL: http://hdl.handle.net/10.1076/mcmd.9.2.193.16519
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Handle: RePEc:taf:nmcmxx:v:9:y:2003:i:2:p:193-208
Template-Type: ReDIF-Article 1.0
Author-Name: R. Rajamani
Author-X-Name-First: R.
Author-X-Name-Last: Rajamani
Author-Name: J. Gohl
Author-X-Name-First: J.
Author-X-Name-Last: Gohl
Author-Name: L. Alexander
Author-X-Name-First: L.
Author-X-Name-Last: Alexander
Author-Name: P. Starr
Author-X-Name-First: P.
Author-X-Name-Last: Starr
Title: Dynamics of Narrow Tilting Vehicles
Abstract:
Narrow commuter vehicles can address many congestion, parking
and pollution issues associated with urban transportation. In making
narrow vehicles safe, comfortable and acceptable to the public, active
tilt control systems are likely to play a crucial role. This paper
concentrates on developing a dynamic model for narrow vehicles that can be
used for the design and evaluation of active tilt control systems. The
model has four degrees of freedom including lateral and tilt dynamics. The
influence of gyroscopic forces due to rotating wheels and the influence of
front wheel trail are included but secondary coupling effects are ignored
so as to keep the model tractable. The model is used in this paper to
understand the influence of vehicle tilt on the steering angle required
for cornering, the desired tilt angle for any specified cornering maneuver
and the influence of gyroscopic moments on transient tilting/cornering
maneuvers. A study of the model equations also provides insight into how
narrow vehicles can be designed so as to be self-stabilizing.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 209-231
Issue: 2
Volume: 9
Year: 2003
Month: 6
X-DOI: 10.1076/mcmd.9.2.209.16521
File-URL: http://hdl.handle.net/10.1076/mcmd.9.2.209.16521
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Handle: RePEc:taf:nmcmxx:v:9:y:2003:i:2:p:209-231
Template-Type: ReDIF-Article 1.0
Author-Name: Z. Huang
Author-X-Name-First: Z.
Author-X-Name-Last: Huang
Author-Name: V. Chandra
Author-X-Name-First: V.
Author-X-Name-Last: Chandra
Author-Name: S. Jiang
Author-X-Name-First: S.
Author-X-Name-Last: Jiang
Author-Name: R. Kumar
Author-X-Name-First: R.
Author-X-Name-Last: Kumar
Title: Modeling Discrete Event Systems With Faults Using a Rules-based Modeling Formalism
Abstract:
Obtaining accurate models of systems which are prone to
failures and breakdowns is a difficult task. In this paper we present a
methodology which makes the task of modeling failure prone discrete event
systems (DESs) considerably less cumbersome, less error prone, and more
user-friendly. The task of obtaining commonly used automata models for
DESs is non-trivial for most practical systems, owing to the fact that the
number of states in the commonly used automata models is exponential in
the number of signals and faults. In contrast a model of a discrete event
system, in the rules based modeling formalism proposed by the co-authors
of this paper, is of size polynomial in the number of signals and faults.
In order to model failures, we augment the signals set of the rules based
formalism to include binary valued fault signals, the values representing
either a non-faulty or a faulty state of a certain failure type. Addition
of new fault signals requires introduction of new rules for the added
fault signal events, and also modification of the existing rules for
non-fault events. The rules based modeling formalism is further extended
to model real-time systems, and we apply it to model delay-faults of the
system as well. The model of a failure prone DES in the rules based can
automatically be converted into an equivalent (timed)-automaton model for
a failure analysis in the automaton model framework.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 233-254
Issue: 3
Volume: 9
Year: 2003
Month: 9
X-DOI: 10.1076/mcmd.9.3.233.24147
File-URL: http://hdl.handle.net/10.1076/mcmd.9.3.233.24147
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Handle: RePEc:taf:nmcmxx:v:9:y:2003:i:3:p:233-254
Template-Type: ReDIF-Article 1.0
Author-Name: V. Chandra
Author-X-Name-First: V.
Author-X-Name-Last: Chandra
Author-Name: Z. Huang
Author-X-Name-First: Z.
Author-X-Name-Last: Huang
Author-Name: W. Qiu
Author-X-Name-First: W.
Author-X-Name-Last: Qiu
Author-Name: R. Kumar
Author-X-Name-First: R.
Author-X-Name-Last: Kumar
Title: Prioritized Composition With Exclusion and Generation for the Interaction and Control of Discrete Event Systems
Abstract:
Interaction of multiple discrete event systems (DESs)
represented as automata are carried out using composition operations.
These operations on automata enforce concurrency, wherein an event exists
in the composed automaton if it exists in the participating states of the
interacting automata possessing the event in their event set. Heymann
generalized this by introducing event priorities, wherein an event exists
in the composed automaton if it exists in the participating state of the
interacting automata having priority over the event. For two interacting
automata P and Q, while prioritized composition can model the P, Q, AND,
and OR boolean interactions, it cannot model boolean interactions which
require exclusivity of participation, namely, “exclusive P”,
“exclusive Q”, “exclusive P or exclusive Q”,
“exclusive P and exclusive Q”. In order to also model these
additional interactions we propose a generalization of prioritized
composition by introducing an exclusivity set besides the existing
priority sets. The resulting composition is called prioritized composition
with exclusion. We also introduce prioritized composition with exclusion
and generation that allows for all sixteen boolean modes of interaction
possible when two automata interact. This is done by the further
introduction of a nor-generative set. This event set together with the two
priority sets and an exclusivity set makes it possible to model eight
additional boolean interactions which do not require either of the
interacting automata to participate for the event to be enabled in the
composed automaton. The applicability of these interactions to
decentralized supervisory decision fusion and in composing the rules based
model of systems has been illustrated.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 255-280
Issue: 3
Volume: 9
Year: 2003
Month: 9
X-DOI: 10.1076/mcmd.9.3.255.24151
File-URL: http://hdl.handle.net/10.1076/mcmd.9.3.255.24151
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Handle: RePEc:taf:nmcmxx:v:9:y:2003:i:3:p:255-280
Template-Type: ReDIF-Article 1.0
Author-Name: Mohamed T. Khadir
Author-X-Name-First: Mohamed T.
Author-X-Name-Last: Khadir
Author-Name: John V. Ringwood
Author-X-Name-First: John V.
Author-X-Name-Last: Ringwood
Title: First Principles Modelling of a Pasteurisation Plant for Model Predictive Control
Abstract:
This paper investigates the physical modelling of an
industrial pasteuriser plant from a control-oriented point of view. The
investigated pasteuriser is based on plate heat exchangers (PHE) of type
Clip 10-RM and brazed heat exchangers (BHE) of type CB76 from Alfa Laval.
The traditionally highly complex and over parameterised models established
for design, dimensioning, and scientific purposes are not suitable for use
within a control strategy in their present form. In this paper, a
simplified first order first principles (FP) model of the PHE sections as
well as the BHE heaters constructing the pasteuriser are developed. An
integrated model of the entire pasteuriser is then constructed combining
the first principles model obtained for different pasteuriser components.
The pasteuriser model parameters are identified, and the model is
validated using data obtained during five test protocol sessions performed
on an industrial process. Finally an example of a model predictive control
(MPC) strategy, using the developed model, is briefly introduced, results
are shown and conclusions are drawn.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 281-301
Issue: 3
Volume: 9
Year: 2003
Month: 9
X-DOI: 10.1076/mcmd.9.3.281.24150
File-URL: http://hdl.handle.net/10.1076/mcmd.9.3.281.24150
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Handle: RePEc:taf:nmcmxx:v:9:y:2003:i:3:p:281-301
Template-Type: ReDIF-Article 1.0
Author-Name: K. Marti
Author-X-Name-First: K.
Author-X-Name-Last: Marti
Title: Plastic Structural Analysis Under Stochastic Uncertainty
Abstract:
Problems from limit load or shakedown analysis are based on
the convex, linear or linearized yield/strength condition and the linear
equilibrium equation for the generic stress vector. Having to take into
account, in practice, stochastic variations of the model parameters (e.g.,
yield stresses, plastic capacities) and external loadings, the basic
stochastic plastic analysis problem must be replaced by an appropriate
deterministic substitute problem. Instead of calculating approximatively
the probability of failure based on a certain choice of failure modes,
here, a direct approach is presented based on the costs for missing
carrying capacity and the failure costs (e.g., costs for damage, repair,
compensation for weakness within the structure, etc.). Based on the basic
mechanical survival conditions, the failure costs may be represented by
the minimum value of a convex and often linear program. Several
mathematical properties of this program are shown. Minimizing then the
total expected costs subject to the remaining (simple) deterministic
constraints, a stochastic optimization problem is obtained which may be
represented by a “Stochastic Convex Program (SCP) with
recourse”. Working with linearized yield/strength conditions, a
“Stochastic Linear Program (SLP) with complete fixed
recourse” is obtained. In case of a discretely distributed
probability distribution or after the discretization of a more general
probability distribution of the random structural parameters and loadings
as well as certain random cost factors one has a linear program (LP) with
a so-called “dual decomposition data” structure. For
stochastic programs of this type many theoretical results and efficient
numerical solution procedures (LP-solver) are available. The mathematical
properties of theses substitute problems are considered. Furthermore
approximate analytical formulas for the limit load factor are given.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 303-325
Issue: 3
Volume: 9
Year: 2003
Month: 9
X-DOI: 10.1076/mcmd.9.3.303.24149
File-URL: http://hdl.handle.net/10.1076/mcmd.9.3.303.24149
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Handle: RePEc:taf:nmcmxx:v:9:y:2003:i:3:p:303-325
Template-Type: ReDIF-Article 1.0
Author-Name: Anatoli Torokhti
Author-X-Name-First: Anatoli
Author-X-Name-Last: Torokhti
Author-Name: Phil Howlett
Author-X-Name-First: Phil
Author-X-Name-Last: Howlett
Author-Name: Charles Pearce
Author-X-Name-First: Charles
Author-X-Name-Last: Pearce
Title: Optimal Mathematical Models for Nonlinear Dynamical Systems
Abstract:
We propose a new method for the optimal causal representation
of nonlinear systems. The proposed approach is based on the best
constrained approximation of mappings in probability spaces by operators
constructed from matrices of special form so that the approximant
preserves the causality property. It is supposed that the observable input
is contaminated with noise. The approximant minimises the mean-square
difference between a desired output signal and the output signal of the
approximating model. The method provides a numerically realisable
mathematical model of the system. An analysis is given of the error
associated with this representation.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 327-343
Issue: 3
Volume: 9
Year: 2003
Month: 9
X-DOI: 10.1076/mcmd.9.3.327.24148
File-URL: http://hdl.handle.net/10.1076/mcmd.9.3.327.24148
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Handle: RePEc:taf:nmcmxx:v:9:y:2003:i:3:p:327-343
Template-Type: ReDIF-Article 1.0
Author-Name: Alexander Weinmann
Author-X-Name-First: Alexander
Author-X-Name-Last: Weinmann
Title: Multi-Lagrange-Multiplier Problems: Desensitized Pole Assignment With Minimal Controller Matrix Norm for Networked Control Systems and Constraints in High-order Mechatronics
Abstract:
From a computational viewpoint, state controllers are
implemented in fixed-point microcontrollers with matrices small in norm
sense. Inaccuracies when implementing K in networked or remote control are
anticipated by including a particular desensitization term. A direct
approach for minimizing the Frobenius norm of the controller matrix is
addressed including the conditions of predetermined eigenvalues of the
closed-loop system. In mechatronics, there is a challenging demand on
optimization augmented by a considerable number of conditions. The problem
is solvable with several equality conditions included by Lagrange
multipliers and interpolation techniques.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 345-362
Issue: 3
Volume: 9
Year: 2003
Month: 9
X-DOI: 10.1076/mcmd.9.3.345.24152
File-URL: http://hdl.handle.net/10.1076/mcmd.9.3.345.24152
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Handle: RePEc:taf:nmcmxx:v:9:y:2003:i:3:p:345-362
Template-Type: ReDIF-Article 1.0
Author-Name: D. Schley
Author-X-Name-First: D.
Author-X-Name-Last: Schley
Author-Name: R.E. Craine
Author-X-Name-First: R.E.
Author-X-Name-Last: Craine
Author-Name: A.A. Birch
Author-X-Name-First: A.A.
Author-X-Name-Last: Birch
Title: Development of a Cerebral Autoregulation Model for Use With Clinical Blood Flow Measurements
Abstract:
Cerebral autoregulation is the mechanism which controls blood
flow to the brain despite variations in blood pressure. Although important
this mechanism is currently not well understood, with autoregulatory
failure difficult to diagnose. In this paper we develop a simple model
based upon those measurements available in the clinical setting. The model
can replicate previous results and is used to investigate a variety of
hypothetical autoregulatory responses. Furthermore the model has been
extended by including the autoregulatory vessels themselves to explain the
observed influence of increased carbon dioxide levels in the blood. A
focus on only those measurements which may be realistically obtained in
human patients avoids the need for estimating many unknown parameters or
the modelling of complex and poorly understood physiological process
necessary in previous, more complicated, models.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 367-386
Issue: 4
Volume: 9
Year: 2003
Month: 12
X-DOI: 10.1076/mcmd.9.4.367.27901
File-URL: http://hdl.handle.net/10.1076/mcmd.9.4.367.27901
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Handle: RePEc:taf:nmcmxx:v:9:y:2003:i:4:p:367-386
Template-Type: ReDIF-Article 1.0
Author-Name: Werner Krabs
Author-X-Name-First: Werner
Author-X-Name-Last: Krabs
Title: A General Predator-Prey Model
Abstract:
We consider n = 2 populations of animals or plants that are
living in mutual predator-prey relations or are pairwise neutral to each
other. We assume the temporal development of the population densities to
be described by a system of differential equations which has an
equilibrium state solution. We at first give sufficient conditions for
this equilibrium state to be asymptotically stable by linearizing the
system around it. Then we derive sufficient conditions for asymptotic
stability by Lyapunov’s method. Finally we investigate a
discretization of the Volterra-Lotka model.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 387-401
Issue: 4
Volume: 9
Year: 2003
Month: 12
X-DOI: 10.1076/mcmd.9.4.387.27896
File-URL: http://hdl.handle.net/10.1076/mcmd.9.4.387.27896
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Handle: RePEc:taf:nmcmxx:v:9:y:2003:i:4:p:387-401
Template-Type: ReDIF-Article 1.0
Author-Name: Daniel S. Zachary
Author-X-Name-First: Daniel S.
Author-X-Name-Last: Zachary
Author-Name: Alain Haurie
Author-X-Name-First: Alain
Author-X-Name-Last: Haurie
Author-Name: Irina Sivergina
Author-X-Name-First: Irina
Author-X-Name-Last: Sivergina
Title: A Reduced-order Photo-chemical Air Quality Model
Abstract:
We report on a reduced-order photo-chemical model
(TAPOM-Lite) designed for calculating ozone levels for varying urban
scenarios and calibrated for the city of Geneva, Switzerland. The
TAPOM-Lite model is an atmospheric-environmental model designed to be
incorporated into a larger energy-economy-environment (E 3) model and run
in an optimization framework. The motivation for the TAPOM-Lite model was
the design of a fast ozone calculator needed for the CPU intensive
optimization environment where many iterations are potentially required
before a best solution is found. Three principal advances in this model
are (1) a simplified chemical scheme for O 3 production, (2) linearization
of the O 3 production function needed for the overseeing linear
optimization program, and (3) the extraction of gradient (sensitivity)
information calculated from the O 3 production function which in turn is
needed as “directional” information in the optimization
method. Results show that the TAPOM-Lite model is consistent with the
full-scale TAPOM model throughout the optimization/iteration process. The
TAPOM-Lite model provides a first coupled energy-economy-environment (E 3)
program for optimization and also provides a framework for global
applications, for example, the linking of global indicators (e.g. mean
temperatures) and world energy consumption.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 403-416
Issue: 4
Volume: 9
Year: 2003
Month: 12
X-DOI: 10.1076/mcmd.9.4.403.27899
File-URL: http://hdl.handle.net/10.1076/mcmd.9.4.403.27899
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Handle: RePEc:taf:nmcmxx:v:9:y:2003:i:4:p:403-416
Template-Type: ReDIF-Article 1.0
Author-Name: Evtim Zahariev
Author-X-Name-First: Evtim
Author-X-Name-Last: Zahariev
Author-Name: John Mcphee
Author-X-Name-First: John
Author-X-Name-Last: Mcphee
Title: Stabilization of Multiple Constraints in Multibody Dynamics Using Optimization and a Pseudo-inverse Matrix
Abstract:
An approach for solving the forward dynamics problem for
mechanical systems with many closed kinematic chains is presented. The
dynamic model takes the form of Differential-Algebraic Equations. An
optimization method for stabilization of kinematic constraints using the
pseudo-inverse mass matrix of the dynamic equations is suggested. The
stabilization algorithm provides minimal deviations of the parameters and
their velocities with respect to the solution of the differential
equations. Estimation of independent coordinates is not required. The
forward and inverse dynamic problems of a spatial mechanism and a spatial
moving platform with many closed chains are solved. The effectiveness of
the algorithm is analyzed.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 417-435
Issue: 4
Volume: 9
Year: 2003
Month: 12
X-DOI: 10.1076/mcmd.9.4.417.27898
File-URL: http://hdl.handle.net/10.1076/mcmd.9.4.417.27898
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Handle: RePEc:taf:nmcmxx:v:9:y:2003:i:4:p:417-435
Template-Type: ReDIF-Article 1.0
Author-Name: Mehmet Önder Efe
Author-X-Name-First: Mehmet Önder
Author-X-Name-Last: Efe
Author-Name: HItay Özbay
Author-X-Name-First: HItay
Author-X-Name-Last: Özbay
Title: Multi Input Dynamical Modeling of Heat Flow With Uncertain Diffusivity Parameter
Abstract:
This paper focuses on the multi-input dynamical modeling of
one-dimensional heat conduction process with uncertainty on thermal
diffusivity parameter. Singular value decomposition is used to extract the
most significant modes. The results of the spatiotemporal decomposition
have been used in cooperation with Galerkin projection to obtain the set
of ordinary differential equations, the solution of which synthesizes the
temporal variables. The spatial properties have been generalized through a
series of test cases and a low order model has been obtained. Since the
value of the thermal diffusivity parameter is not known perfectly, the
obtained model contains uncertainty. The paper describes how the
uncertainty is modeled and how the boundary conditions are separated from
the remaining terms of the dynamical equations. The results have been
compared with those obtained through analytic solution.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 437-450
Issue: 4
Volume: 9
Year: 2003
Month: 12
X-DOI: 10.1076/mcmd.9.4.437.27902
File-URL: http://hdl.handle.net/10.1076/mcmd.9.4.437.27902
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Handle: RePEc:taf:nmcmxx:v:9:y:2003:i:4:p:437-450
Template-Type: ReDIF-Article 1.0
Author-Name: E. Venturino
Author-X-Name-First: E.
Author-X-Name-Last: Venturino
Author-Name: G. Fontana
Author-X-Name-First: G.
Author-X-Name-Last: Fontana
Title: Entrepreneurs, Banks and the Monetary Circuit: A Single Period Investigation
Abstract:
Economic fluctuations constitute a serious problem for policy
makers and economists. Several theories have been developed to explain
their causes. New recent literature has emphasized the idea that the level
of income and employment is determined by decisions taken jointly by banks
and entrepreneurs. Our aim here is to investigate the increasingly
important relationship between banks and entrepreneurs in the monetary
circuit. The system considered explicitly models the money supply process,
in contrast to the current economic literature, in which money is
introduced ex post as an exogenous disturbance. In view of the presence of
several parameters, the two-dimensional model is quite complex. A complete
analysis of all possible outcomes of the ? -limit sets is performed, and
the circumstances under which the system explodes, collapses or tends to
an equilibrium are discussed in terms of the model parameters.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 451-476
Issue: 4
Volume: 9
Year: 2003
Month: 12
X-DOI: 10.1076/mcmd.9.4.451.27900
File-URL: http://hdl.handle.net/10.1076/mcmd.9.4.451.27900
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Handle: RePEc:taf:nmcmxx:v:9:y:2003:i:4:p:451-476
Template-Type: ReDIF-Article 1.0
Author-Name: John McPhee
Author-X-Name-First: John
Author-X-Name-Last: McPhee
Author-Name: Chad Schmitke
Author-X-Name-First: Chad
Author-X-Name-Last: Schmitke
Author-Name: Scott Redmond
Author-X-Name-First: Scott
Author-X-Name-Last: Redmond
Title: Dynamic Modelling of Mechatronic Multibody Systems With Symbolic Computing and Linear Graph Theory
Abstract:
The application of linear graph theory to the modelling of
flexible multibody systems is described. When combined with symbolic
computing methods, linear graph theory leads to efficient dynamic models
that facilitate real-time simulation of systems of rigid bodies and
flexible beams. The natural extension of linear graphs to the modelling of
mechatronic multibody systems is presented, along with a
recently-developed theory for building complex system models from models
of individual subsystems.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 1-23
Issue: 1
Volume: 10
Year: 2004
Month: 3
X-DOI: 10.1080/13873950412331318044
File-URL: http://hdl.handle.net/10.1080/13873950412331318044
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Handle: RePEc:taf:nmcmxx:v:10:y:2004:i:1:p:1-23
Template-Type: ReDIF-Article 1.0
Author-Name: Eberhard Münz
Author-X-Name-First: Eberhard
Author-X-Name-Last: Münz
Author-Name: Thomas Hodrus
Author-X-Name-First: Thomas
Author-X-Name-Last: Hodrus
Author-Name: Volker Krebs
Author-X-Name-First: Volker
Author-X-Name-Last: Krebs
Title: Gradient-Based Identification of Hybrid Systems
Abstract:
An approach for the identification of a class of hybrid
systems is presented. The identification problem for hybrid systems is
formulated as an optimization problem and two possible ways for an
approximative solution of the problem are discussed. As a result of this
discussion a top--down algorithm for the approximative solution is
developed. The proposed algorithm enables the user to incorporate a priori
knowledge in very different scales. The feasibility and performance of the
procedure is demonstrated by identifying a multidimensional hybrid
characteristic map.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 25-40
Issue: 1
Volume: 10
Year: 2004
Month: 3
X-DOI: 10.1080/13873950412331318053
File-URL: http://hdl.handle.net/10.1080/13873950412331318053
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Handle: RePEc:taf:nmcmxx:v:10:y:2004:i:1:p:25-40
Template-Type: ReDIF-Article 1.0
Author-Name: Boštjan Potočnik
Author-X-Name-First: Boštjan
Author-X-Name-Last: Potočnik
Author-Name: Gašper Mušič
Author-X-Name-First: Gašper
Author-X-Name-Last: Mušič
Author-Name: Borut Zupančič
Author-X-Name-First: Borut
Author-X-Name-Last: Zupančič
Title: A New Technique for Translating Discrete Hybrid Automata into Piecewise Affine Systems
Abstract:
The paper proposes a new translation algorithm that
translates a hybrid system described as a discrete hybrid
automaton (DHA) into an equivalent piecewise
affine (PWA) system. The translation algorithm exploits, among
others, a new technique for cell enumeration in hyperplane arrangement,
all proposed in this paper. The new translation technique enables the
transfer of several analysis and synthesis tools developed for PWA systems
to a DHA class of hybrid systems.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 41-57
Issue: 1
Volume: 10
Year: 2004
Month: 3
X-DOI: 10.1080/13873950412331318062
File-URL: http://hdl.handle.net/10.1080/13873950412331318062
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Handle: RePEc:taf:nmcmxx:v:10:y:2004:i:1:p:41-57
Template-Type: ReDIF-Article 1.0
Author-Name: K. Kuhnen
Author-X-Name-First: K.
Author-X-Name-Last: Kuhnen
Author-Name: P. Krejci
Author-X-Name-First: P.
Author-X-Name-Last: Krejci
Title: Identification of Linear Error-Models with Projected Dynamical Systems
Abstract:
Linear error models are an integral part of several parameter
identification methods for feedforward and feedback control systems and
lead in connection with the L
2-norm to a convex distance measure which has to be minimised
for identification purposes. The parameters are hereby often subject to
specific restrictions whose intersections span a convex solution set with
non-differentiability points on its boundary. For solving these well
conditioned problems on-line the paper formulates the solution of the
bounded convex minimisation problem as a stable equilibrium set of a
proper system of differential equations. The vector field of the
corresponding system of differential equations is based on a projection of
the negative gradient of the distance measure. A general drawback of this
approach is the discontinuous right-hand side of the differential equation
caused by the projection transformation. The consequence are difficulties
for the verification of the existence, uniqueness and stability of a
solution trajectory. Therefore the first subject of this paper is the
derivation of an alternative formulation of the projected dynamical
system, which exhibits, in contrast to the original formulation, a
continuous right-hand side and is thus accessible to conventional analysis
methods. For this purpose the multi-dimensional stop operator is used and
the existence, uniqueness and stability properties of the solution
trajectories are established. The second part of this paper deals with the
numerical integration of the projected dynamical system which is used for
an implementation of the identification method on a digital signal
processor for example. To demonstrate the performance the application of
this on-line identification method to the hysteretic filter synthesis with
the modified Prandtl-Ishlinskii approach is presented in the last part of
this paper.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 59-91
Issue: 1
Volume: 10
Year: 2004
Month: 3
X-DOI: 10.1080/13873950412331318071
File-URL: http://hdl.handle.net/10.1080/13873950412331318071
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Handle: RePEc:taf:nmcmxx:v:10:y:2004:i:1:p:59-91
Template-Type: ReDIF-Article 1.0
Author-Name: Joachim Haase
Author-X-Name-First: Joachim
Author-X-Name-Last: Haase
Author-Name: Gerd Pönisch
Author-X-Name-First: Gerd
Author-X-Name-Last: Pönisch
Title: Singular Points in Electromechanical Systems and Their Determination
Abstract:
An approach to determine turning points in electromechanical
systems is presented and applied to the determination of pull-in
parameters. The pull-in phenomenon is an inherent instability in devices
using electrostatic actuation where an electrostatic force works against
an elastic restoring force. The paper presents a relation between
multi-valued characteristics describing MEMS devices and weakly singular
tracking problems. The technique of augmented systems that characterize
turning points is applied to the analytical and numerical determination of
pull-in parameters. The method is discussed using a computer algebra
system and a VHDL-AMS simulation engine.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 107-121
Issue: 2
Volume: 10
Year: 2004
Month: 6
X-DOI: 10.1080/13873950412331318099
File-URL: http://hdl.handle.net/10.1080/13873950412331318099
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Handle: RePEc:taf:nmcmxx:v:10:y:2004:i:2:p:107-121
Template-Type: ReDIF-Article 1.0
Author-Name: Erik Hillgarter
Author-X-Name-First: Erik
Author-X-Name-Last: Hillgarter
Author-Name: Ralf Hemmecke
Author-X-Name-First: Ralf
Author-X-Name-Last: Hemmecke
Author-Name: Günter Landsmann
Author-X-Name-First: Günter
Author-X-Name-Last: Landsmann
Author-Name: Franz Winkler
Author-X-Name-First: Franz
Author-X-Name-Last: Winkler
Title: Symbolic Differential Elimination for Symmetry Analysis
Abstract:
Differential problems are ubiquitous in mathematical modeling
of physical and scientific problems. Algebraic analysis of differential
systems can help in determining qualitative and quantitative properties of
solutions of such systems. In this tutorial paper we describe several
algebraic methods for investigating differential systems.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 123-147
Issue: 2
Volume: 10
Year: 2004
Month: 6
X-DOI: 10.1080/13873950412331318107
File-URL: http://hdl.handle.net/10.1080/13873950412331318107
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Handle: RePEc:taf:nmcmxx:v:10:y:2004:i:2:p:123-147
Template-Type: ReDIF-Article 1.0
Author-Name: N. Scheerlinck
Author-X-Name-First: N.
Author-X-Name-Last: Scheerlinck
Author-Name: A. Peirs
Author-X-Name-First: A.
Author-X-Name-Last: Peirs
Author-Name: M. Desmet
Author-X-Name-First: M.
Author-X-Name-Last: Desmet
Author-Name: A. Schenk
Author-X-Name-First: A.
Author-X-Name-Last: Schenk
Author-Name: B.M. Nicolaï
Author-X-Name-First: B.M.
Author-X-Name-Last: Nicolaï
Title: Modelling Fruit Characteristics During Apple Maturation: A Stochastic Approach
Abstract:
At present, mathematical models to predict the change of
fruit quality attributes during apple maturation are deterministic and do
not take into account the large natural variability of fruit quality
attributes during the growing season. In this work a stochastic system
approach was developed to describe the quality evolution of fruit. The
basic dynamics of fruit quality evolution was represented by means of a
stochastic system, in which the initial conditions and the model
parameters were specified as random variables together with their
probability density functions. A fundamental approach from stochastic
systems theory was used to compute the propagation of the probability
density functions of fruit quality attributes, which requires the
numerical solution of the Fokker--Planck equation.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 149-168
Issue: 2
Volume: 10
Year: 2004
Month: 6
X-DOI: 10.1080/13873950412331318116
File-URL: http://hdl.handle.net/10.1080/13873950412331318116
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Handle: RePEc:taf:nmcmxx:v:10:y:2004:i:2:p:149-168
Template-Type: ReDIF-Article 1.0
Author-Name: Boris Lohmann
Author-X-Name-First: Boris
Author-X-Name-Last: Lohmann
Title: The Autonomous Wheelchair “Easy” and its Hierarchical Control
Abstract:
Robots acting in the proximity of humans belong to the most
challenging mechatronic systems and attract increasing interest in
sciences and in commercial applications. The autonomous wheelchair EASY
(electric wheelchair with driver assistance system) is an example of such
a system of high autonomy. It is developed in the department of System
Dynamics and Control of the Institute of Automation, University of Bremen.
This paper gives an overview of the system and its hierarchical control,
and presents the modelling and feedback control of two particular
sub-problems: the dynamics and trajectory tracking of the wheelchair, and
the 3D vision modelling and image-based path control.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 169-185
Issue: 2
Volume: 10
Year: 2004
Month: 6
X-DOI: 10.1080/13873950412331318125
File-URL: http://hdl.handle.net/10.1080/13873950412331318125
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Handle: RePEc:taf:nmcmxx:v:10:y:2004:i:2:p:169-185
Template-Type: ReDIF-Article 1.0
Author-Name: S. Resatz
Author-X-Name-First: S.
Author-X-Name-Last: Resatz
Author-Name: F. Rattay
Author-X-Name-First: F.
Author-X-Name-Last: Rattay
Title: A Model for the Electrically Stimulated Retina
Abstract:
Many blind people possess functioning bipolar and ganglion
cells, which relay retinal input to the brain. In a two step procedure the
excitation of electrically stimulated retinal cells is simulated: (i) the
extracellular potential along the neural structure is computed (ii) the
target cells are represented by compartment models. Membrane kinetics of
the ganglion cells are evaluated with the Fohlmeister-Colman-Miller model.
Transmembrane voltages of the bipolar cells are calculated for constant
membrane conductance. In retinal ganglion cells the axons are the most
excitable structures when stimulated with short cathodic pulses from
epiretinal electrodes, whereas the axonal endings are the hot spots in
bipolar cells.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 93-106
Issue: 2
Volume: 10
Year: 2004
Month: 6
X-DOI: 10.1080/13873950412331318080
File-URL: http://hdl.handle.net/10.1080/13873950412331318080
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Handle: RePEc:taf:nmcmxx:v:10:y:2004:i:2:p:93-106
Template-Type: ReDIF-Article 1.0
Author-Name: Arif Ankarali
Author-X-Name-First: Arif
Author-X-Name-Last: Ankarali
Author-Name: Mete Kalyoncu
Author-X-Name-First: Mete
Author-X-Name-Last: Kalyoncu
Author-Name: Fatih M. Botsali
Author-X-Name-First: Fatih M.
Author-X-Name-Last: Botsali
Author-Name: Turan şişman
Author-X-Name-First: Turan
Author-X-Name-Last: şişman
Title: Mathematical Modeling and Simulation of a Flexible Shaft-Flexible Link System With End Mass
Abstract:
In this study, the equation of motion of a single link
flexible robotic arm with end mass, which is driven by a flexible shaft,
is obtained by using Hamilton's principle. The physical system is
considered as a continuous system. As a first step, the kinetic energy and
the potential energy terms and the term for work done by the
nonconservative forces are established. Applying Hamilton's principle the
variations are calculated and the time integral is constructed. After a
series of mathematical manipulations the coupled equations of motion of
the physical system and the related boundary conditions are obtained.
Numerical solutions of equations of motion are obtained and discussed for
verification of the model used.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 187-200
Issue: 3-4
Volume: 10
Year: 2004
Month: 9
X-DOI: 10.1080/13873950412331335216
File-URL: http://hdl.handle.net/10.1080/13873950412331335216
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Handle: RePEc:taf:nmcmxx:v:10:y:2004:i:3-4:p:187-200
Template-Type: ReDIF-Article 1.0
Author-Name: Tarek Ahmed-Ali
Author-X-Name-First: Tarek
Author-X-Name-Last: Ahmed-Ali
Author-Name: Fabienne Floret
Author-X-Name-First: Fabienne
Author-X-Name-Last: Floret
Author-Name: Françoise Lamnabhi-Lagarrigue
Author-X-Name-First: Françoise
Author-X-Name-Last: Lamnabhi-Lagarrigue
Title: Robust Identification and Control With Time-varying Parameter Perturbations
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 201-215
Issue: 3-4
Volume: 10
Year: 2004
Month: 9
X-DOI: 10.1080/13873950412331335225
File-URL: http://hdl.handle.net/10.1080/13873950412331335225
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Handle: RePEc:taf:nmcmxx:v:10:y:2004:i:3-4:p:201-215
Template-Type: ReDIF-Article 1.0
Author-Name: Bernhard H. Voglauer
Author-X-Name-First: Bernhard H.
Author-X-Name-Last: Voglauer
Author-Name: Peter Jörgl
Author-X-Name-First: Peter
Author-X-Name-Last: Jörgl
Title: Dynamic Model of a Roast Process for Simulation and Control
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 217-230
Issue: 3-4
Volume: 10
Year: 2004
Month: 9
X-DOI: 10.1080/13873950412331335234
File-URL: http://hdl.handle.net/10.1080/13873950412331335234
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Handle: RePEc:taf:nmcmxx:v:10:y:2004:i:3-4:p:217-230
Template-Type: ReDIF-Article 1.0
Author-Name: Alessandro Macchelli
Author-X-Name-First: Alessandro
Author-X-Name-Last: Macchelli
Author-Name: Claudio Melchiorri
Author-X-Name-First: Claudio
Author-X-Name-Last: Melchiorri
Title: Control by Interconnection and Energy Shaping of the Timoshenko Beam
Abstract:
In this paper, the dynamical control of a mixed finite and
infinite dimensional mechanical system is approached within the framework
of port Hamiltonian systems. In particular, a flexible beam, modeled
according to the Timoshenko theory and in distributed port Hamiltonian
form, with a mass under gravity field connected at a free end, is
considered. The control problem is approached by generalization of the
concept of structural invariant (Casimir function) to the
infinite dimensional case and the so-called control by
interconnection technique is extended to the infinite dimensional
case. In this way, finite dimensional passive controllers can stabilize
distributed parameter systems by shaping their total
energy, i.e., by assigning a new minimum in the desired equilibrium
configuration that can be reached if a dissipation effect is introduced.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 231-251
Issue: 3-4
Volume: 10
Year: 2004
Month: 9
X-DOI: 10.1080/13873950412331335243
File-URL: http://hdl.handle.net/10.1080/13873950412331335243
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Handle: RePEc:taf:nmcmxx:v:10:y:2004:i:3-4:p:231-251
Template-Type: ReDIF-Article 1.0
Author-Name: Johann Reger
Author-X-Name-First: Johann
Author-X-Name-Last: Reger
Author-Name: Klaus Schmidt
Author-X-Name-First: Klaus
Author-X-Name-Last: Schmidt
Title: A Finite Field Framework for Modeling, Analysis and Control of Finite State Automata
Abstract:
In this paper, we address the modeling, analysis and control
of finite state automata, which represent a standard class of discrete
event systems. As opposed to graph theoretical methods, we consider an
algebraic framework that resides on the finite field >formula
form="inline">${\Op F}_2$>/formula> which is defined on a set of two
elements with the operations addition and multiplication, both carried out
modulo 2. The key characteristic of the model is its functional
completeness in the sense that it is capable of describing most of the
finite state automata in use, including non-deterministic and partially
defined automata. Starting from a graphical representation of an automaton
and applying techniques from Boolean algebra, we derive the transition
relation of our finite field model. For cases in which the transition
relation is linear, we develop means for treating the main issues in the
analysis of the cyclic behavior of automata. This involves the computation
of the elementary divisor polynomials of the system dynamics, and the
periods of these polynomials, which are shown to completely determine the
cyclic structure of the state space of the underlying linear system.
Dealing with non-autonomous linear systems with inputs, we use the notion
of feedback in order to specify a desired cyclic behavior of the automaton
in the closed loop. The computation of an appropriate state feedback is
achieved by introducing an image domain and adopting the well-established
polynomial matrix method to linear discrete systems over the finite field
>formula form="inline">${\Op F}_2$>/formula>. Examples illustrate the main
steps of our method.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 253-285
Issue: 3-4
Volume: 10
Year: 2004
Month: 9
X-DOI: 10.1080/13873950412331300142
File-URL: http://hdl.handle.net/10.1080/13873950412331300142
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Handle: RePEc:taf:nmcmxx:v:10:y:2004:i:3-4:p:253-285
Template-Type: ReDIF-Article 1.0
Author-Name: H.S. Chang
Author-X-Name-First: H.S.
Author-X-Name-Last: Chang
Title: A Model for Multi-timescaled Sequential Decision-making Processes with Adversary
Abstract:
Extending the multi-timescale model proposed by the author et
al. in the context of Markov decision processes, this paper proposes a
simple analytical model called M timescale two-person
zero-sum Markov Games (MMGs) for hierarchically structured sequential
decision-making processes in two players' competitive situations where one
player (the minimizer) wishes to minimize their cost that will be paid to
the adversary (the maximizer). In this hierarchical model, for each
player, decisions in each level in the M-level hierarchy
are made in M different discrete timescales and the state
space and the control space of each level in the hierarchy are
non-overlapping with those of the other levels, respectively, and the
hierarchy is structured in a "pyramid" sense such that a decision made at
level m (slower timescale) state and/or the state will
affect the evolutionary decision making process of the lower-level
m+1 (faster timescale) until a new decision is made at
the higher level but the lower-level decisions themselves do not affect
the transition dynamics of higher levels. The performance produced by the
lower-level decisions will affect the higher level decisions for each
player. A hierarchical objective function for the minimizer and the
maximizer is defined, and from this we define "multi-level equilibrium
value function" and derive a "multi-level equilibrium equation". We also
discuss how to solve hierarchical games exactly.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 287-302
Issue: 3-4
Volume: 10
Year: 2004
Month: 9
X-DOI: 10.1080/13873950412331335261
File-URL: http://hdl.handle.net/10.1080/13873950412331335261
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Handle: RePEc:taf:nmcmxx:v:10:y:2004:i:3-4:p:287-302
Template-Type: ReDIF-Article 1.0
Author-Name: I. Krajcin
Author-X-Name-First: I.
Author-X-Name-Last: Krajcin
Author-Name: D. Söffker
Author-X-Name-First: D.
Author-X-Name-Last: Söffker
Title: Model-based Estimation of Contact Forces in Flexible Structures
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 303-316
Issue: 3-4
Volume: 10
Year: 2004
Month: 9
X-DOI: 10.1080/13873950412331335270
File-URL: http://hdl.handle.net/10.1080/13873950412331335270
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Handle: RePEc:taf:nmcmxx:v:10:y:2004:i:3-4:p:303-316
Template-Type: ReDIF-Article 1.0
Author-Name: Behnam Salimbahrami
Author-X-Name-First: Behnam
Author-X-Name-Last: Salimbahrami
Author-Name: Boris Lohmann
Author-X-Name-First: Boris
Author-X-Name-Last: Lohmann
Title: A Simulation-free Nonlinear Model Order-reduction Approach and Comparison Study
Abstract:
In this paper, a new approach to the model order reduction of
nonlinear systems is presented. This approach does not need a simulation
of the original system, and therefore, it is suitable for large systems.
By separating the linear and nonlinear parts of the original nonlinear
model, the idea is to consider the nonlinearities of the resulting system
as additional inputs. Based on the linear system from the last step, a
known order-reduction method can be applied to find the coefficients of
the nonlinear and the linear parts of a reduced-order model. Two different
methods from linear-order reduction (balancing and truncation and
Eitelberg's method with some modification) are used for this purpose, and
their advantages and disadvantages are discussed. For comparison with some
known methods in order reduction of nonlinear systems, three other methods
are discussed briefly. Finally, a technical nonlinear system is reduced,
and different methods are compared.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 317-329
Issue: 3-4
Volume: 10
Year: 2004
Month: 9
X-DOI: 10.1080/13873950412331335289
File-URL: http://hdl.handle.net/10.1080/13873950412331335289
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Handle: RePEc:taf:nmcmxx:v:10:y:2004:i:3-4:p:317-329
Template-Type: ReDIF-Article 1.0
Author-Name: Jeremiah Rushchitsky
Author-X-Name-First: Jeremiah
Author-X-Name-Last: Rushchitsky
Author-Name: Carlo Cattani
Author-X-Name-First: Carlo
Author-X-Name-Last: Cattani
Author-Name: Sergiy Sinchilo
Author-X-Name-First: Sergiy
Author-X-Name-Last: Sinchilo
Title: Cubic Nonlinearity in Elastic Materials: Theoretical Prediction and Computer Modelling of New Wave Effects
Abstract:
Our object of interest is nonlinear interaction of waves in
elastic materials. The new model of a material is proposed that takes into
account the mechanism of simultaneous quadratic and cubic nonlinear
deformations. Introduction of cubic nonlinearity into the model makes the
general wave picture more complicated and creates new possibilities for
the wave analysis. We present four possibilities for the evolution of
profiles of plane harmonic waves. It is noted that quadratic and cubic
nonlinearities emerge first of all in the second and third harmonics
generation, respectively. Further, we discuss the results of computer
modelling of the wave profile evolution. The influence of the progress of
second and third harmonics on the wave profile evolution is studied
separately. We study separately how second and third harmonics influence
the evolution of the wave profile. We also investigate how the progress of
harmonics depends on the initial frequency and amplitude. We find two
distinct schemes of the evolution progress: the scheme (in) with four
stages for the second harmonics and the scheme with three stages for the
third harmonics. As a result the influence of both harmonics could be
observed simultaneously, and such a case is demonstrated in the paper.
Nevertheless this phenomenon is not necessarily present in every material
which explains the absence of experimental observations of the third
harmonics by this time.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 331-352
Issue: 3-4
Volume: 10
Year: 2004
Month: 9
X-DOI: 10.1080/13873950412331335298
File-URL: http://hdl.handle.net/10.1080/13873950412331335298
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:10:y:2004:i:3-4:p:331-352
Template-Type: ReDIF-Article 1.0
Author-Name: J Deutscher
Author-X-Name-First: J
Author-X-Name-Last: Deutscher
Title: Nonlinear model simplification using L 2-optimal bilinearization
Abstract:
This contribution considers the approximation of
nth order nonlinear affine input systems by bilinear
systems of order higher than n to obtain simpler models
for nonlinear control design. The new approach called L
2-optimal bilinearization allows us to specify
beforehand a desired multivariable interval in the state space, where the
resulting bilinear system is an accurate system approximation of the
nonlinear plant under consideration. The accuracy of the approximation
model can be determined by the approximation degree and by specifying the
approximation interval. A systematic approximation procedure for applying
the L 2-optimal bilinearization
is provided and demonstrated via two examples.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 1-19
Issue: 1
Volume: 11
Year: 2005
Month: 3
X-DOI: 10.1080/13873950500052496
File-URL: http://hdl.handle.net/10.1080/13873950500052496
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:1:p:1-19
Template-Type: ReDIF-Article 1.0
Author-Name: D Mukherjee
Author-X-Name-First: D
Author-X-Name-Last: Mukherjee
Title: Co-existence of competing prey with a shared predator
Abstract:
This paper deals with a complex
prey -- predator system, consisting of two competing prey
species and one predator. We derive conditions for persistence. In the
presence of a delay, we estimate the length of delay to maintain
persistence of the system.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 111-121
Issue: 1
Volume: 11
Year: 2005
Month: 3
X-DOI: 10.1080/13873950500052538
File-URL: http://hdl.handle.net/10.1080/13873950500052538
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:1:p:111-121
Template-Type: ReDIF-Article 1.0
Author-Name: X Koutsoukos
Author-X-Name-First: X
Author-X-Name-Last: Koutsoukos
Author-Name: P Antsaklis
Author-X-Name-First: P
Author-X-Name-Last: Antsaklis
Title: Design of piecewise linear hybrid dynamical systems using a control regulator approach
Abstract:
This paper presents a novel framework for hierarchical
control of piecewise linear hybrid dynamical systems. The main
characteristic of this class of hybrid systems is that the continuous
dynamics are described by linear difference equations, the discrete
dynamics by finite automata, and the interaction between the continuous
and the discrete part is defined by piecewise linear maps. Control design
is formulated as a regulator problem and algorithms for the synthesis of
dynamical controllers are developed. Control specifications are modeled as
finite automata. Both static specifications that do not change as time
progresses and dynamic specifications that include sequencing of events
and eventual execution of actions are considered. Control design is
implemented using finite automata and linear programming techniques.
Simulation results of a tank system are used to illustrate the approach.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 21-41
Issue: 1
Volume: 11
Year: 2005
Month: 3
X-DOI: 10.1080/13873950500053023
File-URL: http://hdl.handle.net/10.1080/13873950500053023
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:1:p:21-41
Template-Type: ReDIF-Article 1.0
Author-Name: A Urquia
Author-X-Name-First: A
Author-X-Name-Last: Urquia
Author-Name: C Martin
Author-X-Name-First: C
Author-X-Name-Last: Martin
Author-Name: S Dormido
Author-X-Name-First: S
Author-X-Name-Last: Dormido
Title: Design of SPICE Lib: A Modelica library for modeling and analysis of electric circuits
Abstract:
SPICELib is an
object-oriented model library, written in the Modelica language, that
implements some of the modeling and analysis capabilities of the circuit
simulator PSpice. A novel approach has been adopted in the
SPICELib design. It arises from considering that the
reasons behind the success of PSpice include: the quality of the device
models, the variety of supported analyses and the good performance of the
numerical simulation. As a consequence, SPICELib is
conceived to mimic not only the PSpice device models, but in addition
PSpice capability to perform a variety of circuit analyses and the PSpice
algorithms to calculate the circuit bias point, which is the most
problematic analysis from the numerical standpoint. The
fundamental hypotheses and the architecture of SPICELib
library are discussed, in addition to the modeling of the supported
analyses and devices. A case study is fully developed, in order to
illustrate SPICELib use and validation.
SPICELib version 1.1 (release October 2003) is free
software, and it can be retrieved from the website:
http://www.modelica.org/Conference2003/papers.shtml.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 43-60
Issue: 1
Volume: 11
Year: 2005
Month: 3
X-DOI: 10.1080/13873950500052488
File-URL: http://hdl.handle.net/10.1080/13873950500052488
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:1:p:43-60
Template-Type: ReDIF-Article 1.0
Author-Name: H Ennsbrunner
Author-X-Name-First: H
Author-X-Name-Last: Ennsbrunner
Author-Name: K Schlacher
Author-X-Name-First: K
Author-X-Name-Last: Schlacher
Title: A maple® package for the calculus of variations based on jet manifolds
Abstract:
This contribution presents a computer algebra package for
Lagrangian systems with p ⩾ 1
independent and q ⩾ 1 dependent
variables. The Lagrangian may depend on the partial derivatives up to the
order n ⩾ 0 of the dependent
variables with respect to the independent ones. In the case of one
independent variable, p = 1, the package
derives the equations of motion in the form of a system of
q ordinary differential equations of order
2n, for p > 1 the result
is a system of q partial differential equation up to the
order 2n. In addition the package determines all the
required boundary conditions in the case of
p ⩽ 3 and
n ⩽ 2. Since the presented method
uses the concept of jet manifolds, a short introduction to the notation of
jet theory is provided. Two examples — the Timoshenko beam and the
Kirchhoff plate — demonstrate the main features of the presented
computer algebra based approach.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 61-77
Issue: 1
Volume: 11
Year: 2005
Month: 3
X-DOI: 10.1080/13873950500053056
File-URL: http://hdl.handle.net/10.1080/13873950500053056
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:1:p:61-77
Template-Type: ReDIF-Article 1.0
Author-Name: B Salimbahrami
Author-X-Name-First: B
Author-X-Name-Last: Salimbahrami
Author-Name: B Lohmann
Author-X-Name-First: B
Author-X-Name-Last: Lohmann
Author-Name: T Bechtold
Author-X-Name-First: T
Author-X-Name-Last: Bechtold
Author-Name: JG Korvink
Author-X-Name-First: JG
Author-X-Name-Last: Korvink
Title: A two-sided Arnoldi algorithm with stopping criterion and MIMO selection procedure
Abstract:
In this paper we introduce a two-sided Arnoldi method for the
reduction of high order linear systems and we propose useful extensions,
first of all a stopping criterion to find a suitable order for the reduced
model and secondly, a selection procedure to significantly improve the
performance in the multi-input multi-output (MIMO) case. One application
is in micro-electro-mechanical systems (MEMS). We consider a
thermo-electric micro thruster model, and a comparison between the
commonly used Arnoldi algorithm and the two-sided Arnoldi is performed.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 79-93
Issue: 1
Volume: 11
Year: 2005
Month: 3
X-DOI: 10.1080/13873950500052595
File-URL: http://hdl.handle.net/10.1080/13873950500052595
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:1:p:79-93
Template-Type: ReDIF-Article 1.0
Author-Name: S Blažič
Author-X-Name-First: S
Author-X-Name-Last: Blažič
Author-Name: D Matko
Author-X-Name-First: D
Author-X-Name-Last: Matko
Author-Name: I Škrjanc
Author-X-Name-First: I
Author-X-Name-Last: Škrjanc
Author-Name: G Geiger
Author-X-Name-First: G
Author-X-Name-Last: Geiger
Title: Mathematical modelling of pipelines transporting different fluids
Abstract:
The paper treats the modelling and simulation of pipelines
that transport different fluids. The problem is solved by including the
fluid density in the model beside the pressure and the velocity of the
medium that are used in the models of single medium pipelines. The
starting model consists of nonlinear partial differential equations. Then,
the model is linearised and transformed into the transfer function matrix
form. Four different forms of the model are derived in the paper. Since
transfer functions are transcendent, they cannot be simulated using
classical tools. Rational transfer function approximation of the model is
used instead to validate the model on the real industrial pipeline.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 95-109
Issue: 1
Volume: 11
Year: 2005
Month: 3
X-DOI: 10.1080/138738950500052967
File-URL: http://hdl.handle.net/10.1080/138738950500052967
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:1:p:95-109
Template-Type: ReDIF-Article 1.0
Author-Name: Felix Chernousko
Author-X-Name-First: Felix
Author-X-Name-Last: Chernousko
Author-Name: Boris Polyak
Author-X-Name-First: Boris
Author-X-Name-Last: Polyak
Title: Special issue on the set membership modelling of uncertainties in dynamical systems
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 123-124
Issue: 2
Volume: 11
Year: 2005
Month: 6
X-DOI: 10.1080/13873950500067296
File-URL: http://hdl.handle.net/10.1080/13873950500067296
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:2:p:123-124
Template-Type: ReDIF-Article 1.0
Author-Name: Sergei Aseev
Author-X-Name-First: Sergei
Author-X-Name-Last: Aseev
Author-Name: Gernot Hutschenreiter
Author-X-Name-First: Gernot
Author-X-Name-Last: Hutschenreiter
Author-Name: Arkady Kryazhimskiy
Author-X-Name-First: Arkady
Author-X-Name-Last: Kryazhimskiy
Author-Name: Andrey Lysenko
Author-X-Name-First: Andrey
Author-X-Name-Last: Lysenko
Title: A dynamic model of optimal investment in research and development with international knowledge spillovers
Abstract:
We consider a two-country endogenous growth model where an
economic follower absorbs part of the knowledge generated in a leading
country. To solve a suitably defined infinite horizon dynamic optimization
problem an appropriate version of the Pontryagin maximum principle is
developed. The properties of optimal controls and the corresponding
optimal trajectories are characterized by the qualitative analysis of the
solutions of the Hamiltonian system arising through the implementation of
the Pontryagin maximum principle.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 125-133
Issue: 2
Volume: 11
Year: 2005
Month: 6
X-DOI: 10.1080/1387395050500067361
File-URL: http://hdl.handle.net/10.1080/1387395050500067361
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:2:p:125-133
Template-Type: ReDIF-Article 1.0
Author-Name: F.L. Chernousko
Author-X-Name-First: F.L.
Author-X-Name-Last: Chernousko
Title: Properties of optimal ellipsoids approximating reachable sets of uncertain systems
Abstract:
The ellipsoidal estimation of reachable sets is an efficient
technique for the set-membership modelling of uncertain dynamical systems.
In this paper, the optimal outer ellipsoidal approximation of reachable
sets is considered, and attention is paid to the new criterion associated
with the projection of the approximating ellipsoid onto a given direction.
Nonlinear differential equations governing the evolution of ellipsoids are
analysed and simplified. The asymptotic behaviour of ellipsoids near the
initial point and at infinity is studied. It is shown that the optimal
ellipsoids under consideration touch the corresponding reachable sets at
all time instants. A control problem for a system subjected to uncertain
perturbations is investigated in the framework of the optimal ellipsoidal
estimation of reachable sets.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 135-147
Issue: 2
Volume: 11
Year: 2005
Month: 6
X-DOI: 10.1080/13873950500068427
File-URL: http://hdl.handle.net/10.1080/13873950500068427
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:2:p:135-147
Template-Type: ReDIF-Article 1.0
Author-Name: Tatiana F. Filippova
Author-X-Name-First: Tatiana F.
Author-X-Name-Last: Filippova
Title: Set-valued solutions to impulsive differential inclusions
Abstract:
This paper deals with the state estimation problem for
impulsive control systems described by differential inclusions with
measures. The problem is studied under uncertainty conditions with
set-membership description of uncertain variables which are taken to be
unknown but bounded with given bounds. Such problems arise from
mathematical models of dynamical and physical systems for which we have an
incomplete description of their generalized coordinates (e.g. the model
may contain unpredictable errors without their statistical description).
In this setting instead of an isolated trajectory of the dynamical control
system we have a tube of such trajectories and the phase state vector
should be replaced by the set of its possible values. The techniques of
constructing the trajectory tubes and their cross-sections that may be
considered as set-valued state estimates to differential inclusions with
impulses are studied.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 149-158
Issue: 2
Volume: 11
Year: 2005
Month: 6
X-DOI: 10.1080/13873950500068542
File-URL: http://hdl.handle.net/10.1080/13873950500068542
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:2:p:149-158
Template-Type: ReDIF-Article 1.0
Author-Name: Bolesław Kacewicz
Author-X-Name-First: Bolesław
Author-X-Name-Last: Kacewicz
Title: Optimal and suboptimal algorithms in set membership identification
Abstract:
We discuss in this paper optimality properties of
identification algorithms in a set membership framework. We deal with
restricted-complexity (conditional) identification, where approximations
(models) to a possibly complex system are selected from a low dimensional
space. We discuss the worst- and average-case settings. In the worst-case
setting, we present results on optimality, or suboptimality, of algorithms
based on computing the unconditional or conditional Chebyshev centres of
an uncertainty set. In the average-case setting, we show that the optimal
algorithm is given by the projection of the unconditional Chebyshev
centre. We show explicit formulas for its average errors, allowing us to
see the contribution of all problem parameters to the minimal error. We
discuss the case of weighted average errors corresponding to non-uniform
distributions over uncertainty sets, and show how the weights influence
the minimal identification error.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 159-169
Issue: 2
Volume: 11
Year: 2005
Month: 6
X-DOI: 10.1080/13873950500068575
File-URL: http://hdl.handle.net/10.1080/13873950500068575
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:2:p:159-169
Template-Type: ReDIF-Article 1.0
Author-Name: Michel Kieffer
Author-X-Name-First: Michel
Author-X-Name-Last: Kieffer
Author-Name: Eric Walter
Author-X-Name-First: Eric
Author-X-Name-Last: Walter
Title: Interval analysis for guaranteed non-linear parameter and state estimation
Abstract:
This paper presents some tools based on interval analysis for
guaranteed non-linear parameter and state estimation in a bounded-error
context. These tools make it possible to compute outer (and sometimes
inner) approximations of the set of all parameter or state vectors that
are consistent with the model structure, measurements and noise bounds.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 171-181
Issue: 2
Volume: 11
Year: 2005
Month: 6
X-DOI: 10.1080/13873950500068807
File-URL: http://hdl.handle.net/10.1080/13873950500068807
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:2:p:171-181
Template-Type: ReDIF-Article 1.0
Author-Name: Alexander B. Kurzhanski
Author-X-Name-First: Alexander B.
Author-X-Name-Last: Kurzhanski
Author-Name: Pravin Varaiya
Author-X-Name-First: Pravin
Author-X-Name-Last: Varaiya
Title: Reachability under uncertainty and measurement noise
Abstract:
This paper deals with the problem of reachability
under unknown but bounded disturbances and piecewise open-loop
controls which may be feedback-corrected at isolated
‘points of correction’. It is presumed that there
are hard bounds on the controls and the unknown but bounded items. The
open-loop controls are reassigned at prespecified points of correction on
the basis of additional information on the state space variable which
arrives at these points. Such information typically comes through a given
noisy instantaneous measurement of the state space variable which
sometimes may or may not be complemented by information on the forthcoming
disturbance. Thus the process is ‘piecewise feedback’ with
feedback introduced at points of correction. The described situation is
intermediate relative to purely open-loop control and continuous
measurement feedback control under uncertainty. The novelty of this paper
lies in considering incomplete noisy measurements of the state space
variable at points of correction rather than exact complete measurements
of these. The paper also describes some numerical algorithms relevant for
computer modelling. It is emphasized that effective computational results
may be obtained if one relies on ellipsoidal techniques as given by
Kurzhanski et al.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 183-194
Issue: 2
Volume: 11
Year: 2005
Month: 6
X-DOI: 10.1080/13873950500068831
File-URL: http://hdl.handle.net/10.1080/13873950500068831
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:2:p:183-194
Template-Type: ReDIF-Article 1.0
Author-Name: M. Milanese
Author-X-Name-First: M.
Author-X-Name-Last: Milanese
Author-Name: C. Novara
Author-X-Name-First: C.
Author-X-Name-Last: Novara
Author-Name: L. Pivano
Author-X-Name-First: L.
Author-X-Name-Last: Pivano
Title: Structured SM identification of vehicle vertical dynamics
Abstract:
In this paper the problem of identifying discrete time
nonlinear systems in regression form from finite and noise corrupted
measurements is considered. According to the specifications about
identification accuracy that may be needed, a good exploration of the
regressor domain of interest has to be ensured by the experimental
conditions. This problem becomes very significant for growing dimension of
the regressor space, leading very easily to computational complexity
problems and to inaccurate identified models. These difficulties are
significantly reduced if, using information about the physical structure
of the system to be identified, this can be decomposed into interacting
subsystems. Using this structural information, the high-dimensional
identification problem may be reduced to the identification of lower
dimensional subsystems and to the estimation of their interactions.
Typical cases considered in the literature are Hammerstein, Wiener and
Lur'e systems, but the paper shows that the approach can be extended to
more complex structures composed of many subsystems and with nonlinear
dynamic blocks, using as an example the identification of a half-car model
for vehicle vertical dynamics, where nonlinear suspensions and tyres are
considered. Assuming that the road profile is given and that front and
rear vertical accelerations are measured, an experimental setup easily
realizable in actual experiments on real cars, the half-car model, is
decomposed as a generalized Lur'e system, consisting of a linear MIMO
system, connected in a feedback form with the two nonlinear dynamic
systems through non-measured signals. An iterative identification scheme
is proposed, which makes use of a set membership method for the
identification of the nonlinear dynamic blocks. This method does not
require assumptions on the functional form of the involved nonlinearities,
thus circumventing the identification accuracy problems that may be
generated by considering approximate functional forms. The numerical
results demonstrate the effectiveness of the proposed approach.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 195-207
Issue: 2
Volume: 11
Year: 2005
Month: 6
X-DOI: 10.1080/13873950500068849
File-URL: http://hdl.handle.net/10.1080/13873950500068849
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:2:p:195-207
Template-Type: ReDIF-Article 1.0
Author-Name: J. P. Norton
Author-X-Name-First: J. P.
Author-X-Name-Last: Norton
Title: Results to aid applications of ellipsoidal state bounds
Abstract:
Results to assist in the application of the ellipsoidal
bounds provided by standard state-bounding algorithms are presented. They
include derived bounds on scalar state-dependent quantities and the state
values which determine them, tests of intersection and inclusion of
ellipsoids, measures of how much an ellipsoid may be changed without
altering its inclusion in another, and an ellipsoidal inner bound for the
set reachable in the worst case from an ellipsoidal set by ellipsoidally
bounded forcing, in a linear system. Approximations are suggested for the
most computationally demanding result. Ways in which these results might
be employed in aerospace interception problems are discussed to illustrate
their utility.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 209-224
Issue: 2
Volume: 11
Year: 2005
Month: 6
X-DOI: 10.1080/13873950500069292
File-URL: http://hdl.handle.net/10.1080/13873950500069292
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:2:p:209-224
Template-Type: ReDIF-Article 1.0
Author-Name: Sergey A. Nazin
Author-X-Name-First: Sergey A.
Author-X-Name-Last: Nazin
Author-Name: Boris T. Polyak*
Author-X-Name-First: Boris T.
Author-X-Name-Last: Polyak*
Title: Interval parameter estimation under model uncertainty
Abstract:
This paper is devoted to the estimation of parameters of
linear multi-output models with uncertain regressors and additive noise.
The uncertainty is assumed to be described by intervals. Outer-bounding
interval approximations of the non-convex feasible parameter set for
uncertain systems are obtained. The method is based on the calculation of
the interval solution for an interval system of linear algebraic equations
and provides parameter estimators for models with a large number of
measurements.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 225-237
Issue: 2
Volume: 11
Year: 2005
Month: 6
X-DOI: 10.1080/138950500069243
File-URL: http://hdl.handle.net/10.1080/138950500069243
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:2:p:225-237
Template-Type: ReDIF-Article 1.0
Author-Name: D. Ya. Rokityanskiy
Author-X-Name-First: D. Ya.
Author-X-Name-Last: Rokityanskiy
Author-Name: S. M. Veres
Author-X-Name-First: S. M.
Author-X-Name-Last: Veres
Title: Application of ellipsoidal estimation to satellite control design
Abstract:
The equations of motion of a small satellite moving along a
prescribed trajectory under disturbances are analysed. Problems of this
kind have been extensively investigated. The corresponding equations for
relative motion errors, caused by the uncertainties in initial conditions
and control implementation imperfections, are linearized. The linear
equations are reformulated and the evolution equations for optimal
ellipsoidal estimates of these errors are derived. It is shown that
ellipsoidal bounding of reachable sets is an efficient approach to model
uncertain linear dynamical systems. The procedure constructed in this
paper allows one to take into account discrete observations and to design
control aimed at compensating the disturbances between measurements. These
measurements are assumed to be performed with small errors. A numerical
example is given which illustrates that the presented control design
algorithm is quite efficient and allows one to keep the error between the
real and desired motion close to zero.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 239-249
Issue: 2
Volume: 11
Year: 2005
Month: 6
X-DOI: 10.1080/13873950500069326
File-URL: http://hdl.handle.net/10.1080/13873950500069326
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:2:p:239-249
Template-Type: ReDIF-Article 1.0
Author-Name: Diego Alonso
Author-X-Name-First: Diego
Author-X-Name-Last: Alonso
Author-Name: Federico Robbio
Author-X-Name-First: Federico
Author-X-Name-Last: Robbio
Author-Name: Eduardo Paolini
Author-X-Name-First: Eduardo
Author-X-Name-Last: Paolini
Author-Name: Jorge Moiola
Author-X-Name-First: Jorge
Author-X-Name-Last: Moiola
Title: Modelling an Inertia Wheel Pendulum Benchmark
Abstract:
In this paper, modelling and parameter identification of an
inertia wheel pendulum benchmark is considered. This is an underactuated
mechanical system useful for teaching and research. Attention is focused
on deriving a simple but accurate model capable of reproducing large
amplitude oscillations. Due to the particular design of the prototype, the
friction forces on the actuated joint are noticeable. A simple friction
model including dead-zone effects and viscous terms is proposed, and a
compensation method for the dead zone is derived. The accuracy of the
compensation strategy and the predictive quality of the derived model are
analysed by comparing numerical simulations with experimental data.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 255-272
Issue: 3
Volume: 11
Year: 2005
Month: 9
X-DOI: 10.1080/13873950500076784
File-URL: http://hdl.handle.net/10.1080/13873950500076784
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:3:p:255-272
Template-Type: ReDIF-Article 1.0
Author-Name: B. Balachandran
Author-X-Name-First: B.
Author-X-Name-Last: Balachandran
Author-Name: D. Gilsinn
Author-X-Name-First: D.
Author-X-Name-Last: Gilsinn
Title: Non-linear oscillations of milling
Abstract:
The principal features of two mathematical models that can
be used to study non-linear oscillations of a workpiece - tool system
during a milling operation are presented and explained in this article.
These models are non-linear, non-homogeneous, delay-differential systems
with time-periodic coefficients. In the treatment presented here, the
sources of non-linearities are the multiple regenerative effect and the
loss-of-contact effect. The time-delay effect is taken into account, and
the dependence of this delay effect on the feed rate is modelled. A
variable time delay is introduced to capture the influence of the
feed-rate in one of the models. Two formulations that can be used to carry
out stability analysis of periodic solutions are presented. The models
presented and the stability-analysis formulations are relevant for
predicting and understanding chatter in milling.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 273-290
Issue: 3
Volume: 11
Year: 2005
Month: 9
X-DOI: 10.1080/13873950500076479
File-URL: http://hdl.handle.net/10.1080/13873950500076479
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:3:p:273-290
Template-Type: ReDIF-Article 1.0
Author-Name: Davide Bernardini
Author-X-Name-First: Davide
Author-X-Name-Last: Bernardini
Author-Name: Giuseppe Rega
Author-X-Name-First: Giuseppe
Author-X-Name-Last: Rega
Title: Thermomechanical modelling, nonlinear dynamics and chaos in shape memory oscillators
Abstract:
A constitutive model for the restoring force in
pseudo-elastic shape memory oscillators is proposed. The model is
developed in a thermomechanical framework and allows one to predict the
temperature variations that typically arise in shape memory materials
under dynamical loading. A peculiar feature of the model is that all the
constitutive equations follow from two basic ingredients, the free energy
and the dissipation functions, through the restrictions imposed by the
balance equations, instead of being directly postulated as in standard
internal variable formulations. The model is then implemented and employed
to systematically characterize the nonlinear dynamic response of the
oscillator. It turns out that non-regular responses occur around the jumps
between different branches of frequency - response curves. The features of
the response and the modalities of transition to chaos are described
mainly by means of bifurcation diagrams. The effect of the main model
parameters (pseudo-elastic loop shape and thermal effects) on the dynamics
of the system is also investigated.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 291-314
Issue: 3
Volume: 11
Year: 2005
Month: 9
X-DOI: 10.1080/13873950500076404
File-URL: http://hdl.handle.net/10.1080/13873950500076404
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:3:p:291-314
Template-Type: ReDIF-Article 1.0
Author-Name: Andreas Bockstedte
Author-X-Name-First: Andreas
Author-X-Name-Last: Bockstedte
Author-Name: Edwin Kreuzer
Author-X-Name-First: Edwin
Author-X-Name-Last: Kreuzer
Title: Multibody system model of a cargo airship to study the load exchange process
Abstract:
Projected cargo airships for the transport of large loads
exceed the dimensions of existing aircrafts and gave rise to various
technical problems. One important task in an airship mission is the
loading and unloading of the heavy and spacious load from the payload bay
of the airship. In order to study the dynamics of the load exchange
process, mathematical models of the airship including the oscillating load
frame are developed. The hull together with the load frame represent a
multibody system. Crucial aspects contributing to the dynamics of the
system are the floatation of the flying crane and nonlinear couplings
between hull and load frame. Furthermore, added masses of the surrounding
air are considered. Oscillations of the load frame are excited by wind
loads, airship maneuvers and winding up the cables.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 315-328
Issue: 3
Volume: 11
Year: 2005
Month: 9
X-DOI: 10.1080/13873950500076339
File-URL: http://hdl.handle.net/10.1080/13873950500076339
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:3:p:315-328
Template-Type: ReDIF-Article 1.0
Author-Name: Bernhard Manhartsgruber
Author-X-Name-First: Bernhard
Author-X-Name-Last: Manhartsgruber
Author-Name: Gudrun Mikota
Author-X-Name-First: Gudrun
Author-X-Name-Last: Mikota
Author-Name: Rudolf Scheidl
Author-X-Name-First: Rudolf
Author-X-Name-Last: Scheidl
Title: Modelling of a Switching Control Hydraulic System
Abstract:
Modelling of a hydraulic system featuring a specific type of
switching control is presented. Despite conventional hydraulic drive
technology where rather smooth changes of pressure and flow rate are
intended and where oscillations constitute undesired phenomena, switching
control provokes oscillations as an indispensable element to achieve high
energetic efficiency with valve control. The system under study is one
which comprises a novel switching valve, a long line with considerable
wave propagation dynamics, a hydraulic cylinder, and the valve's dynamics.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 329-344
Issue: 3
Volume: 11
Year: 2005
Month: 9
X-DOI: 10.1080/13873950500076297
File-URL: http://hdl.handle.net/10.1080/13873950500076297
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:3:p:329-344
Template-Type: ReDIF-Article 1.0
Author-Name: K. Popp
Author-X-Name-First: K.
Author-X-Name-Last: Popp
Title: Modelling and control of friction-induced vibrations
Abstract:
Friction-induced vibrations in technical applications are
usually unwanted, as they create noise, diminish accuracy and increase
wear. This article intends to give insight into basic excitation
mechanisms of friction-induced vibrations and to show possible ways of
avoidance. Excitation mechanisms under investigation are a friction
characteristic decreasing with increasing relative velocity, fluctuating
normal forces, non-conservative restoring forces and sprag slip. They are
treated using mechanical models with up to two degrees of freedom.
Analytical and numerical stability analysis as well as numerical time step
integration is used to show the influence of model parameters on the
excitation of friction-induced vibrations. In the second part of the
article, measures to avoid friction-induced vibrations are presented and
explained. Such measures are an increase in external damping, additional
external excitation as well as active and passive vibration control.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 345-369
Issue: 3
Volume: 11
Year: 2005
Month: 9
X-DOI: 10.1080/13873950500076131
File-URL: http://hdl.handle.net/10.1080/13873950500076131
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:3:p:345-369
Template-Type: ReDIF-Article 1.0
Author-Name: Satoshi Suzuki
Author-X-Name-First: Satoshi
Author-X-Name-Last: Suzuki
Author-Name: Katsuhisa Furuta
Author-X-Name-First: Katsuhisa
Author-X-Name-Last: Furuta
Author-Name: Shoshiro Hatakeyama
Author-X-Name-First: Shoshiro
Author-X-Name-Last: Hatakeyama
Title: Passive walking towards running
Abstract:
Passive walking emerges autonomously on a slight slope
without an external input of energy. It is known that the walking motion
on a steep slope evolves into a chaotic motion. In this paper a biped
model for walking and running is presented, and a strategy is proposed to
expand the range of stable passive walking by using a chaos-control
technique based on the Ott -- Grebogi -- Yorke
method. The resultant controller is a discrete type so that the input
value changes at every step, and the generated walking motion is kept
non-chaotic. Fast walking on a steep slope is achieved, and pseudorunning
has also been realized in simulations. By adding an input to the biped
model, in which the input corresponds to the effect of the artificial
gravity field, it has been verified that pseudorunning can be realized on
level ground.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 371-395
Issue: 4
Volume: 11
Year: 2005
Month: 12
X-DOI: 10.1080/13873950500068500
File-URL: http://hdl.handle.net/10.1080/13873950500068500
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:4:p:371-395
Template-Type: ReDIF-Article 1.0
Author-Name: C.L. Chen
Author-X-Name-First: C.L.
Author-X-Name-Last: Chen
Author-Name: K.C. Lin
Author-X-Name-First: K.C.
Author-X-Name-Last: Lin
Author-Name: C. Hsieh
Author-X-Name-First: C.
Author-X-Name-Last: Hsieh
Title: Presliding friction mode: Modelling and experimental study with a ball-screw-driven set-up
Abstract:
To cope with the increasing high precision requirement in
many applications of ball-screw-driven stages, system dynamic behaviour
under friction force should be carefully investigated, especially in the
presliding friction regime. Presliding friction has many special
characteristics such as elasticity, hysteresis with memory and plasticity.
In this paper, dynamic modelling of a ball-screw-driven stage under
presliding friction is experimentally investigated. The model is then
validated by the consistency of results in experiments and simulations.
Despite the complex structure of the system and the complicated nature of
friction, the system can be described by a set of nonlinear state
equations.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 397-410
Issue: 4
Volume: 11
Year: 2005
Month: 12
X-DOI: 10.1080/13873950500067049
File-URL: http://hdl.handle.net/10.1080/13873950500067049
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:4:p:397-410
Template-Type: ReDIF-Article 1.0
Author-Name: Juš Kocijan
Author-X-Name-First: Juš
Author-X-Name-Last: Kocijan
Author-Name: Agathe Girard
Author-X-Name-First: Agathe
Author-X-Name-Last: Girard
Author-Name: Blaž Banko
Author-X-Name-First: Blaž
Author-X-Name-Last: Banko
Author-Name: Roderick Murray-Smith
Author-X-Name-First: Roderick
Author-X-Name-Last: Murray-Smith
Title: Dynamic systems identification with Gaussian processes
Abstract:
This paper describes the identification of nonlinear dynamic
systems with a Gaussian process (GP) prior model. This model is an example
of the use of a probabilistic non-parametric modelling approach. GPs are
flexible models capable of modelling complex nonlinear systems. Also, an
attractive feature of this model is that the variance associated with the
model response is readily obtained, and it can be used to highlight areas
of the input space where prediction quality is poor, owing to the lack of
data or complexity (high variance). We illustrate the GP modelling
technique on a simulated example of a nonlinear system.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 411-424
Issue: 4
Volume: 11
Year: 2005
Month: 12
X-DOI: 10.1080/13873950500068567
File-URL: http://hdl.handle.net/10.1080/13873950500068567
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:4:p:411-424
Template-Type: ReDIF-Article 1.0
Author-Name: Michael Fette
Author-X-Name-First: Michael
Author-X-Name-Last: Fette
Author-Name: Ingo Winzenick
Author-X-Name-First: Ingo
Author-X-Name-Last: Winzenick
Title: Bifurcation analysis of power system load characteristics with continuation methods
Abstract:
Power systems are capable of exhibiting complex dynamics.
Sometimes critical ones are, e.g. nonlinear incidents like collapse and
swing phenomena. Many efforts are made by researchers and operators in
order to prevent and dominate these undesirable effects. It is well known
that parameter variations have influences on the system behavior and its
stability. Sometimes they can cause incidents like the ones mentioned
above. Because of former studies (e.g. in the field of catastrophe theory)
it is also known that very often only a few parameters dominate the system
behavior. An identification of these main parameters is desirable in order
to get more information about the underlying mechanisms. On this basis an
improvement or developement of adequate strategies in order to prevent
critical system states is possible. Limit induced problems due
to parameter variations as well as effects of generator controls on the
system have been investigated in several papers. This paper neglects the
limit induced problems and considers influences of different load
characteristics on the system behavior. Therefore, an appropriate load
model is needed. It is desirable that the chosen model represents the
physical behavior as well as influences of individual parameter.
The presented analysis uses continuation methods and the concepts of
bifurcation theory. Therewith an investigation due to parameter of
interest is possible and furthermore properties of the solution points can
be investigated and classified, too. Moreover, appropriate network models
are needed. An often-used, three-node power system model is chosen here.
It represents the main system behavior and the physical dependencies in
principle. Additionally it is clearly arranged and easy to handle.
This paper presents two major results. At first bifurcation-studies
are made. These studies regard especially load parameter variations. In
contrast to other solutions these results are transformed into so-called
power diagrams. It is possible to use this well known representation to
derive or adapt control schemes. Secondly, the usage of flexible AC
transmission devices (FACTS) is analyzed in order to avoid critical
bifurcations. Although this was studied in several papers before, this
work analyzes again the influences of different load characteristics. As a
result, one gets information about possible limits. In special cases
gain—intervals of the used FACTS—device can be determined
within the system is independent of load parameter variation.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 425-445
Issue: 4
Volume: 11
Year: 2005
Month: 12
X-DOI: 10.1080/13873950500052900
File-URL: http://hdl.handle.net/10.1080/13873950500052900
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:4:p:425-445
Template-Type: ReDIF-Article 1.0
Author-Name: Debasis Mukherjee
Author-X-Name-First: Debasis
Author-X-Name-Last: Mukherjee
Title: Effect of diffusion on a two-species eco-epidemiological model
Abstract:
This paper deals with the stabilizing effect of diffusion on
a prey -- predator system where the prey population is
infected by a microparasite. The predator functional response is a
concave-type function. Conditions for the local as well as global
stability of the model without diffusion are derived in terms of system
parameters. It is also shown that an unstable equilibrium of the model
without diffusion can be made stable by increasing the diffusion
coefficients appropriately.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 447-457
Issue: 4
Volume: 11
Year: 2005
Month: 12
X-DOI: 10.1080/13873950500064293
File-URL: http://hdl.handle.net/10.1080/13873950500064293
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Handle: RePEc:taf:nmcmxx:v:11:y:2005:i:4:p:447-457
Template-Type: ReDIF-Article 1.0
Author-Name: G. Ferretti
Author-X-Name-First: G.
Author-X-Name-Last: Ferretti
Author-Name: P. Rocco
Author-X-Name-First: P.
Author-X-Name-Last: Rocco
Title: Special issue on modular physical modelling
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 1-3
Issue: 1
Volume: 12
Year: 2006
Month: 2
X-DOI: 10.1080/13873950500070860
File-URL: http://hdl.handle.net/10.1080/13873950500070860
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:1:p:1-3
Template-Type: ReDIF-Article 1.0
Author-Name: Francesco Casella
Author-X-Name-First: Francesco
Author-X-Name-Last: Casella
Author-Name: Alberto Leva
Author-X-Name-First: Alberto
Author-X-Name-Last: Leva
Title: Modelling of thermo-hydraulic power generation processes using Modelica
Abstract:
The paper discusses current approaches to the modelling and
simulation of thermo-hydraulic processes, to be used as a tool for system
studies in thermal power plant control. After reviewing the desirable
features of simulation environments, an approach based on the Modelica
language is presented and motivated. Finally, the general concepts
presented above are exemplified by modelling a simple process based on a
heat exchanger.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 19-33
Issue: 1
Volume: 12
Year: 2006
Month: 2
X-DOI: 10.1080/13873950500071082
File-URL: http://hdl.handle.net/10.1080/13873950500071082
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:1:p:19-33
Template-Type: ReDIF-Article 1.0
Author-Name: Felix Felgner
Author-X-Name-First: Felix
Author-X-Name-Last: Felgner
Author-Name: Rolf Merz
Author-X-Name-First: Rolf
Author-X-Name-Last: Merz
Author-Name: Lothar Litz
Author-X-Name-First: Lothar
Author-X-Name-Last: Litz
Title: Modular modelling of thermal building behaviour using Modelica
Abstract:
This article presents a modular model library describing
various processes of thermal building behaviour. The library is
implemented in the modelling language Modelica emulating thermal building
dynamics in a comprehensive way. This includes the heating, ventilation
and air-conditioning system as well as solar radiation and user behaviour.
The way in which the dynamic behaviour of many coupled subsystems can be
investigated in only one universal modelling and simulation environment
will be illustrated. At the same time, the object-oriented and acausal
language Modelica ensures a high degree of reusability. The library is
free and can be downloaded from the website of the Modelica Association:
http://www.modelica.o
rg/libraries.shtml
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 35-49
Issue: 1
Volume: 12
Year: 2006
Month: 2
X-DOI: 10.1080/13873950500071173
File-URL: http://hdl.handle.net/10.1080/13873950500071173
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:1:p:35-49
Template-Type: ReDIF-Article 1.0
Author-Name: Roland Waschler
Author-X-Name-First: Roland
Author-X-Name-Last: Waschler
Author-Name: Odon Angeles‐Palacios
Author-X-Name-First: Odon
Author-X-Name-Last: Angeles‐Palacios
Author-Name: Martin Ginkel
Author-X-Name-First: Martin
Author-X-Name-Last: Ginkel
Author-Name: Achim Kienle
Author-X-Name-First: Achim
Author-X-Name-Last: Kienle
Title: Object-oriented modelling of large-scale chemical engineering processes with ProMoT
Abstract:
The application of the process modelling
tool ProMoT to large-scale chemical engineering processes is presented.
Particular emphasis is on the flexibility of the tool in terms of creating
flowsheet alternatives—a prerequisite for efficient plant design
and control structure selection. The main concepts in this respect are the
bottom-up development of an object-oriented knowledge base for the
simplified implementation of submodels on the level of process units, the
efficient aggregation on the flowsheet level and the flexibility to
effectively perform top-down refinements for problem-specific
applications. All concepts are illustrated on the basis of an industrial
scale process.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 5-18
Issue: 1
Volume: 12
Year: 2006
Month: 2
X-DOI: 10.1080/13873950500071017
File-URL: http://hdl.handle.net/10.1080/13873950500071017
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:1:p:5-18
Template-Type: ReDIF-Article 1.0
Author-Name: W. D. Steinmann
Author-X-Name-First: W. D.
Author-X-Name-Last: Steinmann
Title: Development and application of the Modelica library TechThermo
Abstract:
The general-purpose simulation language Modelica was created
to improve the efficiency of modelling activities by application of
object-oriented principles. The concept of reuse of models demands the
organization of components in libraries. TechThermo is a base library for
simulation of transient systems in engineering thermodynamics. The models
included in this library represent the fundamental processes needed in a
wide range of applications; only problem-specific models must be added.
TechThermo consists of interface definitions, models for imposing boundary
conditions, thermophysical property correlations, descriptions for heat
and mass transfer, models of basic technical components and simplified
subsystems. The simulation of a storage system for a solar -- thermal
power plant is used to demonstrate the application of TechThermo. About
90% of the source code defining this example is contributed by models
taken from TechThermo.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 51-72
Issue: 1
Volume: 12
Year: 2006
Month: 2
X-DOI: 10.1080/13873950500071272
File-URL: http://hdl.handle.net/10.1080/13873950500071272
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:1:p:51-72
Template-Type: ReDIF-Article 1.0
Author-Name: Marco Lovera
Author-X-Name-First: Marco
Author-X-Name-Last: Lovera
Title: Control-oriented modelling and simulation of spacecraft attitude and orbit dynamics
Abstract:
Modelling and simulation of spacecraft
dynamics play a central role in the development process for spacecraft
control systems. In particular, while the requirements for attitude and
orbit control systems are becoming more and more stringent, there is also
a need for adequate design tools in order to cope efficiently with
tightening budgets for space missions. In this paper, the main issues
related to the modelling and simulation of satellite dynamics are
introduced and discussed, and the results obtained so far in developing a
spacecraft simulation library based on the Modelica language are
presented.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 73-88
Issue: 1
Volume: 12
Year: 2006
Month: 2
X-DOI: 10.1080/13873950500071371
File-URL: http://hdl.handle.net/10.1080/13873950500071371
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:1:p:73-88
Template-Type: ReDIF-Article 1.0
Author-Name: Gianni Ferretti
Author-X-Name-First: Gianni
Author-X-Name-Last: Ferretti
Author-Name: Gianantonio Magnani
Author-X-Name-First: Gianantonio
Author-X-Name-Last: Magnani
Author-Name: Paolo Rocco
Author-X-Name-First: Paolo
Author-X-Name-Last: Rocco
Author-Name: Luca Viganò
Author-X-Name-First: Luca
Author-X-Name-Last: Viganò
Title: Modelling and simulation of a gripper with Dymola
Abstract:
As an opportunity to show the evolution of the state of the
art in modular physical modelling, the model of a gripper for space
robotics applications, already developed in the MOSES environment, has
been re-implemented in the Dymola environment, adopting the new Modelica
multibody library recently developed. The new library allows a truly
object-oriented approach, while being efficient from a computational point
of view.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 89-102
Issue: 1
Volume: 12
Year: 2006
Month: 2
X-DOI: 10.1080/13873950500071405
File-URL: http://hdl.handle.net/10.1080/13873950500071405
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:1:p:89-102
Template-Type: ReDIF-Article 1.0
Author-Name: Wolfgang Borutzky
Author-X-Name-First: Wolfgang
Author-X-Name-Last: Borutzky
Author-Name: Peter Gawthrop
Author-X-Name-First: Peter
Author-X-Name-Last: Gawthrop
Title: Bond graph modelling
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 103-105
Issue: 2-3
Volume: 12
Year: 2006
Month: 4
X-DOI: 10.1080/13873950500069078
File-URL: http://hdl.handle.net/10.1080/13873950500069078
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:2-3:p:103-105
Template-Type: ReDIF-Article 1.0
Author-Name: Stephen Birkett
Author-X-Name-First: Stephen
Author-X-Name-Last: Birkett
Author-Name: Jean Thoma
Author-X-Name-First: Jean
Author-X-Name-Last: Thoma
Author-Name: Peter Roe
Author-X-Name-First: Peter
Author-X-Name-Last: Roe
Title: A pedagogical analysis of bond graph and linear graph physical system models
Abstract:
As tools for teaching physical system modelling and
simulation both the bond graph and graph-theoretic methods have clearly
demonstrated value at undergraduate and graduate levels of education, and
in applied industrial contexts. The very close connections between the two
techniques give them various shared attributes in this respect, notably
the three main virtues of physical analogy, capability for causal analysis
and the cross-disciplinary universality of the energy flow representation.
An outline is given of the main technical features, and how these relate
to the pedagogical virtues, as well as an account of the complete
technical equivalence of bond graphs and linear graphs as representations
of a discrete physical system. Several important misconceptions about this
relationship are discussed and clarified, including continued doubts about
methodological equivalence, apparent differences that can be attributed to
arbitrary formality and convention, and the non-use of some
graph-theoretic equation formulation procedures with a bond graph model.
Despite these facts, teaching experience has demonstrated that a degree of
pedagogical asymmetry still exists between the bond graph and linear graph
approaches. This situation is explained through differences in model
symbolism and, in particular, as a consequence of following different
pathways to arrive at the simultaneous port and terminal representations
that characterize either model. The existence of an extensive resource of
universal, flexible computer software for implementing and analysing bond
graph physical system models is also an important factor which is not
available for linear graph modelling, an important practical consideration
that is likely to have curtailed the widespread use of the latter method
in pedagogical situations.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 107-125
Issue: 2-3
Volume: 12
Year: 2006
Month: 4
X-DOI: 10.1080/13873950500069052
File-URL: http://hdl.handle.net/10.1080/13873950500069052
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:2-3:p:107-125
Template-Type: ReDIF-Article 1.0
Author-Name: Eric Bideaux
Author-X-Name-First: Eric
Author-X-Name-Last: Bideaux
Author-Name: Wilfrid Marquis-Favre
Author-X-Name-First: Wilfrid
Author-X-Name-Last: Marquis-Favre
Author-Name: Serge Scavarda
Author-X-Name-First: Serge
Author-X-Name-Last: Scavarda
Title: Equilibrium set investigation using bicausality
Abstract:
The introduction of the bicausality concept in the bond graph
language has allowed new analytical methodologies, for instance in the
context of model inversion, mechatronic system sizing and control. The
bicausality concept is here applied for solving the equilibrium state of a
mechatronic system. We propose a new method, which permits us to determine
the size of the equilibrium set and the algebraic system to be solved. The
proposed method is applied to linear systems in a first step, and a
generalization is also given for some non-linear systems. Several examples
are included in order to explain the method.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 127-140
Issue: 2-3
Volume: 12
Year: 2006
Month: 4
X-DOI: 10.1080/13873950500069003
File-URL: http://hdl.handle.net/10.1080/13873950500069003
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:2-3:p:127-140
Template-Type: ReDIF-Article 1.0
Author-Name: W. Borutzky
Author-X-Name-First: W.
Author-X-Name-Last: Borutzky
Author-Name: G. Dauphin-Tanguy
Author-X-Name-First: G.
Author-X-Name-Last: Dauphin-Tanguy
Author-Name: C. Kam
Author-X-Name-First: C.
Author-X-Name-Last: Kam
Title: Relations between two bond graph approaches to sensitivity analysis and study of robustness
Abstract:
Recently Borutzky and Granda proposed to construct a
so-called incremental bond graph from an initial bond
graph with nominal parameters in order to determine unnormalized first
order frequency domain sensitivities in symbolic form. At the same time
Dauphin-Tanguy and Kam presented a bond graph approach that allowed them
to set up a specific form of state equations in symbolic form commonly
used for a robustness study of models with uncertain parameters. Both
approaches designed for different purposes have been developed
independently. Nevertheless, this paper shows that they can be used to
obtain each other's results under some reasonable assumptions. For
illustration both approaches are applied to an example, which has been
kept fairly small for didactic reasons.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 141-157
Issue: 2-3
Volume: 12
Year: 2006
Month: 4
X-DOI: 10.1080/13873950500068955
File-URL: http://hdl.handle.net/10.1080/13873950500068955
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:2-3:p:141-157
Template-Type: ReDIF-Article 1.0
Author-Name: F. Couenne
Author-X-Name-First: F.
Author-X-Name-Last: Couenne
Author-Name: C. Jallut
Author-X-Name-First: C.
Author-X-Name-Last: Jallut
Author-Name: B. Maschke
Author-X-Name-First: B.
Author-X-Name-Last: Maschke
Author-Name: P.C. Breedveld
Author-X-Name-First: P.C.
Author-X-Name-Last: Breedveld
Author-Name: M. Tayakout
Author-X-Name-First: M.
Author-X-Name-Last: Tayakout
Title: Bond graph modelling for chemical reactors
Abstract:
In this paper we present a bond graph model of a continuous
stirred tank reactor which represents the reaction kinetics as well as the
heat and mass transport phenomena in the reactor. The consequences of
reticulation of the phenomena and of the systematic use of the power
conjugated variables on the formulation of the thermodynamic properties,
the reaction kinetics and the energy and mass transport are shown. A
classical example of chemical reaction is chosen to illustrate this
approach: the equilibrated reaction of hydrogen and iodine in hydrogen
iodide.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 159-174
Issue: 2-3
Volume: 12
Year: 2006
Month: 4
X-DOI: 10.1080/13873950500068823
File-URL: http://hdl.handle.net/10.1080/13873950500068823
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:2-3:p:159-174
Template-Type: ReDIF-Article 1.0
Author-Name: Vjekoslav Damić
Author-X-Name-First: Vjekoslav
Author-X-Name-Last: Damić
Title: Modelling flexible body systems: a bond graph component model approach
Abstract:
Recent developments in mechatronic systems, such as robotics
and flexible manipulators, require a systematic, multidisciplinary
approach to design. Bond graphs provide a general modelling paradigm that
can be used in design of such multi-domain physical systems. Modelling the
dynamics of flexible body systems has been the subject of active research
over the last two decades. Model development is not simple when such
systems undergo large translational and/or rotational displacements, and
this has led to several modelling approaches. Bond graphs can be used
successfully to design such systems. This paper treats slender deformable
bodies as a collection of finite-element beams. Model development employs
bond graphs based on a co-rotational formulation. This approach differs
from others in that it uses a velocity formulation, instead of the more
common positional formulation. The bond graph component model approach
enables systematic creation of models of rigid and deformable multibody
systems as a tree of component models, the leaves of which are the
elementary components that represent the underlying physical processes.
This facilitates building complex models of dynamic systems. The
mathematical representation of this structure can be formulated as a
system of differential-algebraic equations (DAEs) amenable to solution by
readily available techniques. BondSim, an integrated
modelling and simulation environment, facilitates this modelling process.
A beam element model developed as a bond graph component is applied to the
well-known spin-up manoeuvre of a flexible beam, a problem often used to
test the validity of flexible-body models. The results show that a model
developed using bond graphs is capable of predicting rather subtle
centrifugal stiffening effects. Bond graphs thus provide a sound paradigm
for developing mathematical models of such multi-domain, multibody
systems.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 175-187
Issue: 2-3
Volume: 12
Year: 2006
Month: 4
X-DOI: 10.1080/13873950500068757
File-URL: http://hdl.handle.net/10.1080/13873950500068757
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:2-3:p:175-187
Template-Type: ReDIF-Article 1.0
Author-Name: Wilfrid Marquis-Favre
Author-X-Name-First: Wilfrid
Author-X-Name-Last: Marquis-Favre
Author-Name: Eric Bideaux
Author-X-Name-First: Eric
Author-X-Name-Last: Bideaux
Author-Name: Olivier Mechin
Author-X-Name-First: Olivier
Author-X-Name-Last: Mechin
Author-Name: Serge Scavarda
Author-X-Name-First: Serge
Author-X-Name-Last: Scavarda
Author-Name: Franck Guillemard
Author-X-Name-First: Franck
Author-X-Name-Last: Guillemard
Author-Name: Marc Ebalard
Author-X-Name-First: Marc
Author-X-Name-Last: Ebalard
Title: Mechatronic bond graph modelling of an automotive vehicle
Abstract:
Automotive manufacturers have created vehicle models but
these are somewhat complex and use black boxes with numerous tables and
mappings. Each model is generally valid for its own field of use and can
thus produce significant differences in results outside its specific
field. Moreover vehicle behaviour requires detailing and analysis during
precise manoeuvres called ‘life situations'. These ‘life
situations' require different models to be set up. A complete vehicle
model is necessary when attempting to reproduce simulated realistic
behaviours for different manoeuvres. High modelling standards are also
sought when vehicle systems such as steering, suspension or braking are
approached. This paper presents bond graph modelling of an automotive
vehicle with 16 degrees of freedom. Although not presented here, one
purpose of such a model is dimensioning of different vehicle systems, in
certain life situations, using an inverse approach. The vehicle body is
modelled by a rigid body with six degrees of freedom. Each wheel has two
degrees of freedom, one corresponding to vertical suspension deflection,
the other to wheel axial rotation. Each front wheel has one additional
degree of freedom corresponding to steering mobility. Vehicle components
modelled and connected to the body model are thus four suspensions, wheels
and steering system. Simulations of this model have been undertaken on
20Sim. They reveal good correlation with a model simulated on AMESim by
automotive manufacturer PSA Peugeot Citroën, considered as the
validation reference for this study.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 189-202
Issue: 2-3
Volume: 12
Year: 2006
Month: 4
X-DOI: 10.1080/13873950500068732
File-URL: http://hdl.handle.net/10.1080/13873950500068732
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:2-3:p:189-202
Template-Type: ReDIF-Article 1.0
Author-Name: Loucas S. Louca
Author-X-Name-First: Loucas S.
Author-X-Name-Last: Louca
Author-Name: B. Umut Yildir
Author-X-Name-First: B. Umut
Author-X-Name-Last: Yildir
Title: Modelling and reduction techniques for studies of integrated hybrid vehicle systems
Abstract:
Models of integrated vehicle systems are essential for
designing hybrid vehicles by means of simulation-based optimization. Given
the complexity of hybrid vehicle systems, designing is a time consuming
process that requires the evaluation of a large number of different design
configurations. Modelling and simulation can significantly reduce the
design time through efficient design evaluations and reduced number of
prototypes built. This work presents the development and reduction of an
integrated hybrid vehicle model composed of an engine, drivetrain,
hydraulics and vehicle dynamics subsystems. For model development the bond
graph formulation is used because it facilitates the integration of
component/subsystem models in different energy domains, supports
hierarchical modelling and allows straightforward manipulation of the
model. The model is configured for a medium size military truck, and
implemented in the 20SIM modelling and simulation environment. After
developing the model, an energy-based model reduction methodology is
applied in order to generate a reduced vehicle model that provides more
design insight. The generated reduced system model for the hybrid truck
(compared to the full model) produces almost identical predictions, has
almost half the size and calculates the system response 2.5 times faster.
This computationally efficient reduced model can be used for vehicle
design studies to further reduce the development time.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 203-218
Issue: 2-3
Volume: 12
Year: 2006
Month: 4
X-DOI: 10.1080/13873950500068690
File-URL: http://hdl.handle.net/10.1080/13873950500068690
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:2-3:p:203-218
Template-Type: ReDIF-Article 1.0
Author-Name: César Pichardo-Almarza
Author-X-Name-First: César
Author-X-Name-Last: Pichardo-Almarza
Author-Name: Ahmed Rahmani
Author-X-Name-First: Ahmed
Author-X-Name-Last: Rahmani
Author-Name: Geneviève Dauphin-Tanguy
Author-X-Name-First: Geneviève
Author-X-Name-Last: Dauphin-Tanguy
Author-Name: Marisol Delgado
Author-X-Name-First: Marisol
Author-X-Name-Last: Delgado
Title: Luenberger observers for linear time-invariant systems modelled by bond graphs
Abstract:
This paper shows how to build Luenberger observers for linear
time-invariant systems modelled by bond graph. The methods are based on
Luenberger's algebraic methods to design both full-order and reduced-order
observers. The procedure for reduced-order observers uses the bicausality
concept to simplify some classical matrix calculations (the calculation of
matrix inverses is not needed), which is an important improvement mainly
for large-scale systems. The calculation of the observer gains is based on
the pole-placement techniques for linear systems modelled by bond graphs.
As an application, both observers are designed for a vehicle suspension
modelled by bond graphs.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 219-234
Issue: 2-3
Volume: 12
Year: 2006
Month: 4
X-DOI: 10.1080/13873950500068666
File-URL: http://hdl.handle.net/10.1080/13873950500068666
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:2-3:p:219-234
Template-Type: ReDIF-Article 1.0
Author-Name: Ahmed Rahmani
Author-X-Name-First: Ahmed
Author-X-Name-Last: Rahmani
Author-Name: Geneviève Dauphin-Tanguy
Author-X-Name-First: Geneviève
Author-X-Name-Last: Dauphin-Tanguy
Title: Structural analysis of switching systems modelled by bond graph
Abstract:
This paper deals with some structural properties for
switching devices modelled by bond graphs. To calculate the structural
rank of the state matrices, to point out impulse modes and to study the
structural controllability and observability, graphical methods are
proposed. These methods are based on simple causal paths and causal
manipulations on the bond graph model.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 235-247
Issue: 2-3
Volume: 12
Year: 2006
Month: 4
X-DOI: 10.1080/1383950500068344
File-URL: http://hdl.handle.net/10.1080/1383950500068344
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:2-3:p:235-247
Template-Type: ReDIF-Article 1.0
Author-Name: D. Vink
Author-X-Name-First: D.
Author-X-Name-Last: Vink
Author-Name: D. Ballance
Author-X-Name-First: D.
Author-X-Name-Last: Ballance
Author-Name: P. Gawthrop
Author-X-Name-First: P.
Author-X-Name-Last: Gawthrop
Title: Bond graphs in model matching control
Abstract:
Bond graphs are primarily used in the network modeling of
lumped parameter physical systems, but controller design with this
graphical technique is relatively unexplored. It is shown that bond graphs
can be used as a tool for certain model matching control designs. Some
basic facts on the nonlinear model matching problem are recalled. The
model matching problem is then associated with a particular disturbance
decoupling problem, and it is demonstrated that bicausal assignment
methods for bond graphs can be applied to solve the disturbance decoupling
problem as to meet the model matching objective. The adopted bond graph
approach is presented through a detailed example, which shows that the
obtained controller induces port-Hamiltonian error dynamics. As a result,
the closed loop system has an associated standard bond graph
representation, thereby rendering energy shaping and damping injection
possible from within a graphical context.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 249-261
Issue: 2-3
Volume: 12
Year: 2006
Month: 4
X-DOI: 10.1080/13873950500068278
File-URL: http://hdl.handle.net/10.1080/13873950500068278
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:2-3:p:249-261
Template-Type: ReDIF-Article 1.0
Author-Name: C. Stupperich-Sequeira
Author-X-Name-First: C.
Author-X-Name-Last: Stupperich-Sequeira
Author-Name: K. Graf
Author-X-Name-First: K.
Author-X-Name-Last: Graf
Author-Name: W. Wiechert
Author-X-Name-First: W.
Author-X-Name-Last: Wiechert
Title: Modelling and simulation of micro-well formation
Abstract:
Physico-chemical processes on the micro-scale require new
modelling concepts because some effects become dominating that are
negligible for macroscopic systems. This is illustrated by a new method
for the production of micro-wells based on the placement of a small drop
of toluene on a plate of polystyrene. After droplet evaporation, a
micro-well is left. A mathematical model has been developed to understand
the elementary processes of the micro-well formation. The model accounts
for: (1) growth of the drop on the substrate, (2) evaporation process of
the solvent, (3) dissolution of the substrate, (4) flow rate in the
evaporating drop caused by the pinning effect, including the vertical
velocity profile, and (5) increase in the concentration of dissolved
material followed by precipitation. In the modelling and simulation
process, it could be shown that the method of drop production also has a
significant influence on the shape of the micro-wells.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 263-276
Issue: 4
Volume: 12
Year: 2006
Month: 8
X-DOI: 10.1080/13873950500067023
File-URL: http://hdl.handle.net/10.1080/13873950500067023
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:4:p:263-276
Template-Type: ReDIF-Article 1.0
Author-Name: Frederick Bloom
Author-X-Name-First: Frederick
Author-X-Name-Last: Bloom
Title: A mathematical model of continuous flotation deinking
Abstract:
A mathematical model is formulated to study the evolution of
a continuous flotation process; the model yields a lower bound for the
long-time deinking efficiency. Some of the theoretical predictions of the
model are analysed using data obtained at a recycle mill.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 277-311
Issue: 4
Volume: 12
Year: 2006
Month: 8
X-DOI: 10.1080/14786410500062189
File-URL: http://hdl.handle.net/10.1080/14786410500062189
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:4:p:277-311
Template-Type: ReDIF-Article 1.0
Author-Name: Antonio Sciarretta
Author-X-Name-First: Antonio
Author-X-Name-Last: Sciarretta
Title: A lattice gas model with temperature and buoyancy effects to predict the concentration of pollutant gas released by power plants and traffic sources
Abstract:
A method to simulate the dispersion of pollutant gases in the
air, which is based on the lattice gas technique, is presented. The model
is able to represent the main transient and local effects, thus it is an
alternative to the direct numerical simulation of the turbulent diffusion
paths. No parametrization of the turbulence is needed, nor of the momentum
and energy exchange between the pollutant and the air. Few non-dimensional
parameters define completely the case to study. The predictions of the
model, including the buoyancy effects, are compared in the steady-state
limit with the Gaussian plume equation. The effective values of the
dispersion coefficients and of the plume rise height are extracted from
the results and are compared with the values resulting from the
application of the most widely used semi-empirical correlations.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 313-327
Issue: 4
Volume: 12
Year: 2006
Month: 8
X-DOI: 10.1080/13873950500068559
File-URL: http://hdl.handle.net/10.1080/13873950500068559
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:4:p:313-327
Template-Type: ReDIF-Article 1.0
Author-Name: Yahya H. Zweiri
Author-X-Name-First: Yahya H.
Author-X-Name-Last: Zweiri
Author-Name: Lakmal D. Seneviratne
Author-X-Name-First: Lakmal D.
Author-X-Name-Last: Seneviratne
Author-Name: Kaspar Althoefer
Author-X-Name-First: Kaspar
Author-X-Name-Last: Althoefer
Title: Modelling of closed-chain manipulators on an excavator vehicle
Abstract:
The main focus of this paper is to develop a physics-based
model for a closed-chain manipulator in an excavator vehicle. The
derivation of closed-chain manipulator dynamic equations with a structure
similar to open-chain manipulator equations is an important research
problem, particularly with reference to controller design. In this paper,
an approach for deriving closed-chain manipulator equations with an
open-chain structure, based on trigonometric t-formulae,
is presented. Holonomic loop closure constraints are employed in order to
derive the closed-chain mechanism dynamics from the reduced system
dynamics. The closed-chain equations, with a structure similar to serial
link equations, are presented. The model incorporates the dynamic
properties of the manipulator and bucket. The dynamic model for the
excavation system is validated against measured data obtained from a
full-scale closed-chain excavator vehicle. A dynamic model is important
for the design of control strategies for trajectory tracking, a key
requirement for automating the excavation task. It is noted that even
though the results presented in this paper are focused on a particular
excavator vehicle, the research is generic and can be adapted to any
closed-chain manipulator.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 329-345
Issue: 4
Volume: 12
Year: 2006
Month: 8
X-DOI: 10.1080/13873950500067007
File-URL: http://hdl.handle.net/10.1080/13873950500067007
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:4:p:329-345
Template-Type: ReDIF-Article 1.0
Author-Name: Riccardo Morselli
Author-X-Name-First: Riccardo
Author-X-Name-Last: Morselli
Author-Name: Roberto Zanasi
Author-X-Name-First: Roberto
Author-X-Name-Last: Zanasi
Author-Name: Germano Sandoni
Author-X-Name-First: Germano
Author-X-Name-Last: Sandoni
Title: Detailed and reduced dynamic models of passive and active limited-slip car differentials
Abstract:
Passive and active limited-slip differentials are used in
high-performance cars to optimize the torque distribution on the driving
wheels for traction maximization, driving comfort, stability and active
safety of the vehicle. In this paper, detailed and reduced dynamic models
for the simulation of four kinds of differential are presented. The models
refer to the limited-slip steering differential with two clutches. The
model of the conventional differential, of the mechanical limited-slip
differential and of the controlled limited-slip differential can be
obtained by simplification. The detailed model allows the simulation of
the internal phenomena that influence the differential dynamics. The
reduced model focuses only on the main dynamic behaviour of the
differential. Some simulations show the use of the reduced model to
compare the effects of the four differentials on the vehicle dynamics.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 347-362
Issue: 4
Volume: 12
Year: 2006
Month: 8
X-DOI: 10.1080/13873950500066959
File-URL: http://hdl.handle.net/10.1080/13873950500066959
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:4:p:347-362
Template-Type: ReDIF-Article 1.0
Author-Name: Yassine Koubaa
Author-X-Name-First: Yassine
Author-X-Name-Last: Koubaa
Title: Application of least-squares techniques for induction motor parameters estimation
Abstract:
This paper deals with a new approach to the parameters
estimation of three-phase induction motors with least-squares techniques.
The identification method is based on the steady-state electrical
equations of induction motor and allows the use of linear identification
algorithms. Measurements of the stator currents and voltages and rotor
angular speed are required for the identification procedure based on a
simple algorithm. The main feature of the proposed procedure is the
possibility of estimating the rotor resistance, self-inductance of the
rotor winding and the stator leakage inductance parameters without
measuring the rotor flux magnitude. The estimated parameters are compared
with similar available data obtained with a 3 kW induction motor to
evaluate the consistence and performance of the proposed method.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 363-375
Issue: 4
Volume: 12
Year: 2006
Month: 8
X-DOI: 10.1080/13873950500064103
File-URL: http://hdl.handle.net/10.1080/13873950500064103
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:4:p:363-375
Template-Type: ReDIF-Article 1.0
Author-Name: A. K. Dramé
Author-X-Name-First: A. K.
Author-X-Name-Last: Dramé
Author-Name: J. Harmand
Author-X-Name-First: J.
Author-X-Name-Last: Harmand
Author-Name: A. Rapaport
Author-X-Name-First: A.
Author-X-Name-Last: Rapaport
Author-Name: C. Lobry
Author-X-Name-First: C.
Author-X-Name-Last: Lobry
Title: Multiple steady state profiles in interconnected biological systems
Abstract:
This paper deals with a generic approach for the analysis of
interconnected biological systems. The equilibrium points as well as the
asymptotic behaviour of these systems are investigated from a qualitative
point of view. In particular, a new generic approach is used to show that
a series of Continuously Stirred Tank Reactors (CSTRs) can exhibit
multiple steady state profiles, for any non-monotonic kinetics. This
multiplicity property disappears when the number of reactors becomes
sufficiently large (for a given total volume). These results are to be
taken in account when CSTRs in series are used to approximate a Piston
Flow Reactor (PFR).
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 379-393
Issue: 5
Volume: 12
Year: 2006
Month: 10
X-DOI: 10.1080/13873950600723277
File-URL: http://hdl.handle.net/10.1080/13873950600723277
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:5:p:379-393
Template-Type: ReDIF-Article 1.0
Author-Name: Dirk J.W. De Pauw
Author-X-Name-First: Dirk J.W.
Author-X-Name-Last: De Pauw
Author-Name: Peter A. Vanrolleghem
Author-X-Name-First: Peter A.
Author-X-Name-Last: Vanrolleghem
Title: Practical aspects of sensitivity function approximation for dynamic models
Abstract:
Sensitivity analysis can be used to quantify the magnitude of
the dependency of model predictions on certain modelling assumptions, e.g.
parameter values, initial conditions or inputs. The finite difference
method, a local sensitivity analysis technique, is discussed in detail and
situated among other methods. A lot of attention is paid to the practical
issues concerning the implementation of this technique, more specifically
the effect of nonlinearities of the model and numerical problems. The
influence of the perturbation factor on the sensitivity calculations is
investigated and different criteria are proposed to assess the quality of
the sensitivity functions. A threshold value with good probability of
detecting faulty sensitivity function calculations was found for one of
these criteria, implying that the method can be automated.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 395-414
Issue: 5
Volume: 12
Year: 2006
Month: 10
X-DOI: 10.1080/13873950600723301
File-URL: http://hdl.handle.net/10.1080/13873950600723301
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:5:p:395-414
Template-Type: ReDIF-Article 1.0
Author-Name: A. Vande Wouwer
Author-X-Name-First: A. Vande
Author-X-Name-Last: Wouwer
Author-Name: C. Renotte
Author-X-Name-First: C.
Author-X-Name-Last: Renotte
Author-Name: Ph. Bogaerts
Author-X-Name-First: Ph.
Author-X-Name-Last: Bogaerts
Title: A short note on SPSA techniques and their use in nonlinear bioprocess identification
Abstract:
Simultaneous perturbation stochastic approximation (SPSA) is
a gradient-based optimization method which has become popular since the
1990s. In contrast with standard numerical procedures, this method
requires only a few cost function evaluations to obtain gradient
information, and can therefore be advantageously applied when identifying
a large number of unknown model parameters, as for instance in neural
network models or first-principles models. In this paper, a first-order
SPSA algorithm is introduced, which makes use of adaptive gain sequences,
gradient smoothing and a step rejection procedure to enhance convergence
and stability. The algorithm performance is illustrated with the
estimation of the most-likely kinetic parameters and initial conditions of
a bioprocess model describing the evolution of batch animal cell cultures.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 415-422
Issue: 5
Volume: 12
Year: 2006
Month: 10
X-DOI: 10.1080/13873950600723327
File-URL: http://hdl.handle.net/10.1080/13873950600723327
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:5:p:415-422
Template-Type: ReDIF-Article 1.0
Author-Name: A. Vande Wouwer
Author-X-Name-First: A. Vande
Author-X-Name-Last: Wouwer
Author-Name: C. Renotte
Author-X-Name-First: C.
Author-X-Name-Last: Renotte
Author-Name: I. Queinnec
Author-X-Name-First: I.
Author-X-Name-Last: Queinnec
Author-Name: Ph. Bogaerts
Author-X-Name-First: Ph.
Author-X-Name-Last: Bogaerts
Title: Transient analysis of a wastewater treatment biofilter -- distributed parameter modelling and state estimation
Abstract:
This paper is concerned with a pilot-scale fixed-bed
biofilter used for nitrogen removal from municipal wastewater. Process
modelling yields a set of mass balance partial differential equations
describing the evolution of the component concentrations along the
biofilter. Based on sets of experimental data collected over several
months, unknown model parameters are estimated by minimizing an
output-error criterion. The resulting distributed parameter model and a
few pointwise measurements of nitrate, nitrite, and ethanol concentrations
are then used to design observers allowing the unmeasured biomass
concentrations to be reconstructed on-line. First, it is demonstrated that
asymptotic observers are not applicable to the given model structure.
Then, a receding-horizon observer is designed and tested, showing a very
satisfactory performance.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 423-440
Issue: 5
Volume: 12
Year: 2006
Month: 10
X-DOI: 10.1080/13873950600723335
File-URL: http://hdl.handle.net/10.1080/13873950600723335
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:5:p:423-440
Template-Type: ReDIF-Article 1.0
Author-Name: Ingmar Nopens
Author-X-Name-First: Ingmar
Author-X-Name-Last: Nopens
Author-Name: Peter A. Vanrolleghem
Author-X-Name-First: Peter A.
Author-X-Name-Last: Vanrolleghem
Title: Comparison of discretization methods to solve a population balance model of activated sludge flocculation including aggregation and breakage
Abstract:
Population balance models (PBMs) can be used to describe the
evolution with time of distributions of properties of individuals. In this
study a PBM for activated sludge flocculation including aggregation and
breakage processes was investigated. The PBM is an integro-differential
equation and does not have an analytical solution. A possibe method of
solving the equation at relatively low computational cost is to use
discretization. Two different discretization techniques, the fixed pivot
and the moving pivot, were compared using geometric grids of different
coarseness. Simulations were performed for three different processes: pure
aggregation, pure breakage and combined aggregation -- breakage.
The results for pure aggregation showed that the fixed pivot overpredicts
the large particle sizes when using coarse grids since grid refinement
results in a clear downward trend. The predictions of the moving pivot
technique show even lower predictions for the large particle sizes, with a
slight upward trend for finer grids. This suggests that these predictions
are closer to the pseudo-analytical solution (i.e. at infinitely fine
grid). For the pure breakage case it was found that the moving pivot
predictions collapsed onto one curve. Since a binary breakage case was
studied, a fixed pivot with a grid with geometric factor 2 also collapsed
onto that curve. Grid refinement for the fixed pivot case resulted in
overestimations. Similar conclusions could be drawn for the combined
aggregation -- breakage case. Overall, the moving pivot is found
to be superior since it produces more accurate predictions, even for much
coarser grids. Despite the computational burden, the latter implies a
lower computational load.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 441-454
Issue: 5
Volume: 12
Year: 2006
Month: 10
X-DOI: 10.1080/13873950600723376
File-URL: http://hdl.handle.net/10.1080/13873950600723376
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:5:p:441-454
Template-Type: ReDIF-Article 1.0
Author-Name: L. B. Verdickt
Author-X-Name-First: L. B.
Author-X-Name-Last: Verdickt
Author-Name: T. V. Voitovich
Author-X-Name-First: T. V.
Author-X-Name-Last: Voitovich
Author-Name: S. Vandewalle
Author-X-Name-First: S.
Author-X-Name-Last: Vandewalle
Author-Name: K. Lust
Author-X-Name-First: K.
Author-X-Name-Last: Lust
Author-Name: I. Y. Smets
Author-X-Name-First: I. Y.
Author-X-Name-Last: Smets
Author-Name: J. F. Van Impe
Author-X-Name-First: J. F.
Author-X-Name-Last: Van Impe
Title: Role of the diffusion coefficient in one-dimensional convection -- diffusion models for sedimentation/thickening in secondary settling tanks
Abstract:
In this paper, the role of the diffusion coefficient in
one-dimensional convection -- diffusion models for secondary
settling tanks is addressed. A simulation analysis is performed using a
representative convection -- diffusion model to demonstrate the
large sensitivity of the model solutions with respect to the value of the
diffusion coefficient. In addition, it is illustrated that the numerical
behaviour of the model is strongly influenced by the value of the
diffusion coefficient. As the results of the simulation study clearly
demonstrate the crucial role of the diffusion coefficient in
convection -- diffusion models, accurate calibration of the
diffusion coefficient is of utmost importance when using such models.
Therefore, a new closure for the evaluation of a spatially dependent
diffusion coefficient is introduced and analysed.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 455-468
Issue: 5
Volume: 12
Year: 2006
Month: 10
X-DOI: 10.1080/13873950600723426
File-URL: http://hdl.handle.net/10.1080/13873950600723426
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:5:p:455-468
Template-Type: ReDIF-Article 1.0
Author-Name: Oscar H. Sendín
Author-X-Name-First: Oscar H.
Author-X-Name-Last: Sendín
Author-Name: Julio Vera
Author-X-Name-First: Julio
Author-X-Name-Last: Vera
Author-Name: Nestor V. Torres
Author-X-Name-First: Nestor V.
Author-X-Name-Last: Torres
Author-Name: Julio R. Banga
Author-X-Name-First: Julio R.
Author-X-Name-Last: Banga
Title: Model based optimization of biochemical systems using multiple objectives: a comparison of several solution strategies
Abstract:
In this work we consider multi-objective optimization
problems arising from the domain of biochemical systems, namely metabolic
pathways, with the ethanol production by Saccharomyces
cerevisiae as a case study. The goals are to maximize the rate of
production of ethanol and simultaneously minimize several internal
metabolite concentrations, imposing additional constraints in order to
ensure cell viability. As a result, the Pareto-optimal set is obtained for
different formulations of the optimization problem. Starting from a
detailed, nonlinear, kinetic model of the pathway, several recent solution
strategies and other well-known techniques are compared, highlighting the
advantages and drawbacks of each one.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 469-487
Issue: 5
Volume: 12
Year: 2006
Month: 10
X-DOI: 10.1080/13873950600723442
File-URL: http://hdl.handle.net/10.1080/13873950600723442
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:5:p:469-487
Template-Type: ReDIF-Article 1.0
Author-Name: Ilse Smets
Author-X-Name-First: Ilse
Author-X-Name-Last: Smets
Author-Name: Liesbeth Verdickt
Author-X-Name-First: Liesbeth
Author-X-Name-Last: Verdickt
Author-Name: Jan Van Impe
Author-X-Name-First: Jan
Author-X-Name-Last: Van Impe
Title: A linear ASM1 based multi-model for activated sludge systems
Abstract:
In the search for a reliable but simple model for the
biodegradation processes of an activated sludge wastewater treatment
plant, this paper presents a multi-model which is valid for the global
operating region of a standard carbon and nitrogen removing facility. In a
first step, locally valid linear models are derived. Two linearization
procedures are compared. The first procedure is the classical Taylor
series expansion, while the second is a newly developed linearization
procedure based on weighted linear combinations. In a second step, the
locally valid models are combined to obtain one globally valid
multi-model. Previous work has focused on the most basic configuration of
one anoxic and one aerated tank followed by a point settler [Smets, I.Y.,
Haegebaert, J.V. and Carrette, R. and Van Impe, J.F., 2003, Water
Research, 37, 1831 -- 1851]. Refinements
to the methodology are however needed (and presented here) once the
influent flow rate range is increased and the benchmark configuration,
proposed by the COST 682 working group no. 2, is taken as the simulation
protocol. The main advantage of the obtained linear model (structure)
remains the alliance of high predictive power with low complexity,
rendering the multi-model fit for on-line optimization and control
schemes.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 489-503
Issue: 5
Volume: 12
Year: 2006
Month: 10
X-DOI: 10.1080/13873950600723467
File-URL: http://hdl.handle.net/10.1080/13873950600723467
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:5:p:489-503
Template-Type: ReDIF-Article 1.0
Author-Name: D. Matko
Author-X-Name-First: D.
Author-X-Name-Last: Matko
Author-Name: G. Geiger
Author-X-Name-First: G.
Author-X-Name-Last: Geiger
Author-Name: T. Werner
Author-X-Name-First: T.
Author-X-Name-Last: Werner
Title: Neural net versus classical models for the detection and localization of leaks in pipelines
Abstract:
Four models of a pipeline are compared in the paper: a
nonlinear distributed-parameter model, a linear distributed-parameter
model, a simplified lumped-parameter model and an extended
neural-net-based model. The transcendental transfer function of the
linearized model is obtained by a Laplace transformation and corresponding
initial and boundary conditions. The lumped-parameter model is obtained by
a Taylor series extension of the transencdental transfer function. Based
on the experience of linear models the structure of the neural net model,
as an addendum to the nonlinear distributed-parameter model, is obtained.
All four models are tested on a real pipeline data with an artificially
generated leak.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 505-517
Issue: 6
Volume: 12
Year: 2006
Month: 12
X-DOI: 10.1080/13873950500068526
File-URL: http://hdl.handle.net/10.1080/13873950500068526
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:6:p:505-517
Template-Type: ReDIF-Article 1.0
Author-Name: Gernot Schullerus
Author-X-Name-First: Gernot
Author-X-Name-Last: Schullerus
Author-Name: Peerasan Supavatanakul
Author-X-Name-First: Peerasan
Author-X-Name-Last: Supavatanakul
Author-Name: Volker Krebs
Author-X-Name-First: Volker
Author-X-Name-Last: Krebs
Author-Name: Jan Lunze
Author-X-Name-First: Jan
Author-X-Name-Last: Lunze
Title: Modelling and hierarchical diagnosis of timed discrete-event systems
Abstract:
A new diagnostic method for hierarchically structured
discrete-event systems is presented. The efficiency of this method results
from the fact that the complexity of the diagnostic task is reduced by
first detecting a faulty component using a coarse process model on a high
level of abstraction, and subsequently refining the result by
investigating the faulty component with the help of a detailed component
model in order to identify the fault with sufficient precision. On both
abstraction levels, the method uses a timed discrete-event model of the
appropriate part of the system. On the higher abstraction level a timed
event graph is used that describes how the temporal distance of the events
is changed by component faults. On the lower level of abstraction, timed
automata are used to cope with the non-determinism of the event sequence
generated by the faulty and faultless components. The approach is
illustrated by the diagnosis of a batch process.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 519-542
Issue: 6
Volume: 12
Year: 2006
Month: 12
X-DOI: 10.1080/13873950500241479
File-URL: http://hdl.handle.net/10.1080/13873950500241479
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:6:p:519-542
Template-Type: ReDIF-Article 1.0
Author-Name: W. Blajer
Author-X-Name-First: W.
Author-X-Name-Last: Blajer
Author-Name: K. Kołodziejczyk
Author-X-Name-First: K.
Author-X-Name-Last: Kołodziejczyk
Title: Modelling and simulation of a sphere rolling on the inside of a rough vertical cylinder
Abstract:
A classical problem of nonholonomic system
dynamics—the motion of a sphere on the inside of a rough vertical
cylinder—is extended to rolling friction. The case study is
modelled in independent coordinates. Due to the nonholonomic constraints
imposed on the sphere, the governing equations arise as a set of
differential-algebraic equations. The results of numerical simulations
show the transition of the sphere from a sinusoid path on the vertical
cylinder surface to a fall with slip. The physics of the
‘paradoxical’ motion is explained in detail.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 543-553
Issue: 6
Volume: 12
Year: 2006
Month: 12
X-DOI: 10.1080/13873950500098747
File-URL: http://hdl.handle.net/10.1080/13873950500098747
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:6:p:543-553
Template-Type: ReDIF-Article 1.0
Author-Name: Scott A. Stevens
Author-X-Name-First: Scott A.
Author-X-Name-Last: Stevens
Author-Name: William D. Lakin
Author-X-Name-First: William D.
Author-X-Name-Last: Lakin
Title: A mathematical model of the systemic circulatory system with logistically defined nervous system regulatory mechanisms
Abstract:
A mathematical model is developed that accurately describes
the pressure, volume and flow dynamics of the systemic circulatory system
over the full physiological range of human pressures and volumes. At the
heart of this model are mathematical representations for the autonomic and
central nervous system reflexes which maintain arterial pressure, cardiac
output and cerebral blood flow. These representations involve functions in
which a maximum effect and a minimum effect are smoothly connected by a
logistic transition. A new approach to modelling the
pressure -- volume relationship in a vessel with smooth muscle
contraction is also presented. To test the model, simulations of cardiac
arrest and various haemorrhagic situations were conducted, and predicted
results were compared with clinical observations. Near-perfect agreement
was obtained between predicted and observed values of the mean circulatory
filling pressure, cardiac output and arterial pressure decay in the face
of significant haemorrhage, and the critical values delineating
progressive from non-progressive hypovolaemic shock.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 555-576
Issue: 6
Volume: 12
Year: 2006
Month: 12
X-DOI: 10.1080/13873950500064343
File-URL: http://hdl.handle.net/10.1080/13873950500064343
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:6:p:555-576
Template-Type: ReDIF-Article 1.0
Author-Name: W. Krabs
Author-X-Name-First: W.
Author-X-Name-Last: Krabs
Title: Stability in predator -- prey models and discretization of a modified Volterra -- Lotka model
Abstract:
We consider n ⩾ 2
populations of animals that are living in mutual
predator -- prey relations or are pairwise neutral to each
other. We assume the temporal development of the population densities to
be described by a system of differential equations which has an
equilibrium state solution. We derive sufficient conditions for this
equilibrium state to be stable by Lyapunov's method. The results
supplement those published elsewhere. Further we consider a
modification of the Volterra -- Lotka model which admits an
asymptotically stable steady state solution. This model is discretized in
two ways and we investigate how small the time step size has to be chosen
in order to guarantee that the steady state solution is an attractive
fixed point of the discretized model. This investigation is connected with
the determination of the model parameters from given data.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 577-588
Issue: 6
Volume: 12
Year: 2006
Month: 12
X-DOI: 10.1080/13873950500066967
File-URL: http://hdl.handle.net/10.1080/13873950500066967
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:6:p:577-588
Template-Type: ReDIF-Article 1.0
Author-Name: Ulrich Konigorski
Author-X-Name-First: Ulrich
Author-X-Name-Last: Konigorski
Title: Algebraic modelling of linear systems by means of Walsh functions
Abstract:
In this paper a new algebraic representation of linear
time-variant dynamic systems is developed. It is shown that Walsh
functions can be used to provide such a representation up to any desired
precision. Due to the orthogonality of the Walsh functions, the required
precision only depends on the number of Walsh functions used in the
underlying Walsh -- Fourier analysis. The resulting linear
algebraic model bears some resemblance to the well-known Laplace transform
and especially in the case of linear time-invariant systems there is even
a direct link between the two descriptions. Based upon this result new
procedures for simulation, system identification and controller design can
be obtained. This is illustrated by calculating stairstep approximations
of the inverse Laplace transform of rational and irrational systems as
well as the design of a time-variant multivariable PI controller for a
sixth-order linear time-variant system.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 589-605
Issue: 6
Volume: 12
Year: 2006
Month: 12
X-DOI: 10.1080/13873950500067064
File-URL: http://hdl.handle.net/10.1080/13873950500067064
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Handle: RePEc:taf:nmcmxx:v:12:y:2006:i:6:p:589-605
Template-Type: ReDIF-Article 1.0
Author-Name: Martin Bodestedt
Author-X-Name-First: Martin
Author-X-Name-Last: Bodestedt
Author-Name: Caren Tischendorf
Author-X-Name-First: Caren
Author-X-Name-Last: Tischendorf
Title: PDAE models of integrated circuits and index analysis
Abstract:
A coupled system modelling an electric circuit containing
semiconductors is presented. The modified nodal analysis leads to a
differential algebraic equation (DAE) describing the electric network. The
nonlinear behaviour of the semiconductors is modelled by the drift
diffusion equations. Coupling relations are defined and a generalization
of the tractability index to systems of infinite dimensions is presented
and applied to the resulting partial differential algebraic equation
(PDAE). The PDAE turns out to have the same index as the electrical
network equations.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 1-17
Issue: 1
Volume: 13
Year: 2007
Month: 2
X-DOI: 10.1080/13873950600557329
File-URL: http://hdl.handle.net/10.1080/13873950600557329
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:1:p:1-17
Template-Type: ReDIF-Article 1.0
Author-Name: H. Loose
Author-X-Name-First: H.
Author-X-Name-Last: Loose
Author-Name: R. Pauli
Author-X-Name-First: R.
Author-X-Name-Last: Pauli
Title: Network modelling of a class of Surface Acoustic Wave filters
Abstract:
We focus on the modelling aspects of a wide class of Surface
Acoustic Wave (SAW) filters built by cascading two electro-acoustic
transducer three-ports that convert electrical signals into acoustic waves
on a piezoelectric substrate, and vice versa. It is this conversion of
voltages or currents into acoustic waves that requires the use of
mixed coordinates for the natural parameterization of SAW
transducers. This modelling problem in mixed coordinates offers a variety
of basic and interesting aspects that might be useful in other fields. On
the level of a general black-box description, we develop a systematic
theory of ‘mixed’ matrix representations including cascade
decomposition, lossless or Darlington embedding, state-space realization,
and additional constraints imposed by losslessness and reciprocity.
Hereby, we identify Redheffer's star product and the pertaining linear
fractional transformation as the main structural elements of the
underlying matrix algebra. At the detailed level, we are not interested in
the analysis and modelling of the various physical
effects. Instead, we look for a linear network model that produces
rational transfer functions and parameterizes them by
physically measurable quantities (reflection and excitation coefficients),
that is, we present a mathematically tractable network model for SAW
filters that is simple enough to serve as the basis for the future
solution of the synthesis problem of such structures
under idealized assumptions.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 19-43
Issue: 1
Volume: 13
Year: 2007
Month: 2
X-DOI: 10.1080/13873950500421170
File-URL: http://hdl.handle.net/10.1080/13873950500421170
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:1:p:19-43
Template-Type: ReDIF-Article 1.0
Author-Name: Tomaž Kolenko
Author-X-Name-First: Tomaž
Author-X-Name-Last: Kolenko
Author-Name: Anton Jaklič
Author-X-Name-First: Anton
Author-X-Name-Last: Jaklič
Author-Name: Jakob Lamut
Author-X-Name-First: Jakob
Author-X-Name-Last: Lamut
Title: Development of a mathematical model for continuous casting of steel slabs and billets
Abstract:
A mathematical model of continuous casting of steel slabs and
billets that takes into account aspects relating to computer capacities
was developed. The starting point for the model was the solution of a
partial differential equation of heat conduction for different boundary
conditions using the finite-difference method. A numerical solution
technique was implemented via the Pascal and C computer programs running
under the GNU/Linux operating system, and their speeds of computation were
compared. The model is capable of predicting temperature profiles and the
solidification front in continuously cast steel strand to make slabs and
billets. The accuracy of the model was tested by obtaining approximate
solutions with two different sets of mesh points, one with half the
spacing of the other, and the temperatures at four representative spatial
positions were compared. The ability of the mathematical model
built to predict the temperature distribution and the shell thickness
reliably was tested using a solidified shell from the mould of the
continuous casting machine for steel billets situated at Štore
Steel, Slovenia.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 45-61
Issue: 1
Volume: 13
Year: 2007
Month: 2
X-DOI: 10.1080/13873950500521508
File-URL: http://hdl.handle.net/10.1080/13873950500521508
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:1:p:45-61
Template-Type: ReDIF-Article 1.0
Author-Name: R. V. Petrova
Author-X-Name-First: R. V.
Author-X-Name-Last: Petrova
Author-Name: K. Hoffmann
Author-X-Name-First: K.
Author-X-Name-Last: Hoffmann
Author-Name: R. Liehl
Author-X-Name-First: R.
Author-X-Name-Last: Liehl
Title: Modelling and simulation of bicable ropeways under cross-wind influence
Abstract:
Improvements of safety standards of ropeways are crucial in
order to ensure a high level of operational reliability and safety. In
this context, the question of cross-wind stability of ropeways is of
particular concern. The real cross-inclination of the gondola and its
correlation to wind speed and direction on an operating ropeway are of
great interest for ropeway manufacturers and responsible authorities as
well as for ropeway operators. As presented in this paper, a mathematical
model for simulation was developed in order to gain a better understanding
of the cross-wind behaviour of bicable ropeways. This model was
established for a numerical dynamic simulation of the movement of gondolas
with stiff connections, ‘hanger-cabins’, due to arbitrary
cross-wind loads acting at a section of the studied span of the ropeway.
All equations were solved using the program MATLAB® and the toolbox
SIMULINK®. In addition, the results of a simulation of a real ropeway
are presented.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 63-81
Issue: 1
Volume: 13
Year: 2007
Month: 2
X-DOI: 10.1080/13873950600562907
File-URL: http://hdl.handle.net/10.1080/13873950600562907
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:1:p:63-81
Template-Type: ReDIF-Article 1.0
Author-Name: F. Siebel
Author-X-Name-First: F.
Author-X-Name-Last: Siebel
Author-Name: W. Mauser
Author-X-Name-First: W.
Author-X-Name-Last: Mauser
Title: Simulating vehicular traffic in a network using dynamic routing
Abstract:
We present a new numerical code which solves the
Lighthill -- Whitham model, the classic macroscopic model for
vehicular traffic flow, in a network with multi-destinations. We use a
high-resolution shock-capturing scheme with approximate Riemann solver to
solve the partial differential equations of the
Lighthill -- Whitham theory. These schemes are very efficient,
robust and moreover well adapted to simulations of traffic flows. We
develop a theory of dynamic routing including a procedure for traffic flow
assignment at junctions which reproduces the correct propagation of
irregularities and ensures at the same time conservation of the number of
vehicles.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 83-97
Issue: 1
Volume: 13
Year: 2007
Month: 2
X-DOI: 10.1080/09687630500103713
File-URL: http://hdl.handle.net/10.1080/09687630500103713
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:1:p:83-97
Template-Type: ReDIF-Article 1.0
Author-Name: Samrat Chatterjee
Author-X-Name-First: Samrat
Author-X-Name-Last: Chatterjee
Author-Name: J. Chattopadhyay
Author-X-Name-First: J.
Author-X-Name-Last: Chattopadhyay
Title: Role of migratory bird population in a simple eco-epidemiological model
Abstract:
Migratory birds play a vital role in the spread of diseases
such as West Nile Virus, Salmonella, etc. In this paper we propose and
analyse (both analytically and numerically) a single-season mathematical
model to observe the dynamical changes that take place due to the
introduction of a disease by migratory birds. We observe that the force of
infection and the predation rate play important roles in maintaining
stability around the positive steady state. We also observe that proper
predation may even result in the extinction of the infective migratory
prey population from the system.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 99-114
Issue: 1
Volume: 13
Year: 2007
Month: 2
X-DOI: 10.1080/13873950500303352
File-URL: http://hdl.handle.net/10.1080/13873950500303352
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:1:p:99-114
Template-Type: ReDIF-Article 1.0
Author-Name: M. Rachkov
Author-X-Name-First: M.
Author-X-Name-Last: Rachkov
Author-Name: L. Marques
Author-X-Name-First: L.
Author-X-Name-Last: Marques
Author-Name: A. De Almeida
Author-X-Name-First: A.
Author-X-Name-Last: De Almeida
Title: Stochastic control of helicopter suspended load position
Abstract:
Modelling of the motion of a helicopter with a suspended load
is described. The mathematical model takes into account stochastic
disturbances acting on the load suspension point. The proposed approach
allows solution of the problem of optimal control with minimization of
oscillation and control power expenditure. The evolution of the system
solution with time is investigated for various disturbance intensities.
Computer calculation results are presented as a function of the suspension
length and the intensity of stochastic disturbances.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 115-124
Issue: 2
Volume: 13
Year: 2007
Month: 4
X-DOI: 10.1080/13873950600739091
File-URL: http://hdl.handle.net/10.1080/13873950600739091
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:2:p:115-124
Template-Type: ReDIF-Article 1.0
Author-Name: Young Man Cho
Author-X-Name-First: Young Man
Author-X-Name-Last: Cho
Author-Name: Sriram Srinavasan
Author-X-Name-First: Sriram
Author-X-Name-Last: Srinavasan
Author-Name: Jae-Hyuk Oh
Author-X-Name-First: Jae-Hyuk
Author-X-Name-Last: Oh
Author-Name: Hwa Soo Kim
Author-X-Name-First: Hwa Soo
Author-X-Name-Last: Kim
Title: Modelling and system identification of active magnetic bearing systems
Abstract:
Active magnetic bearing (AMB) systems have recently attracted
much attention in the rotating machinery industry due to their advantages
over traditional bearings such as fluid film and rolling element bearings.
The AMB control system must provide robust performance over a wide range
of machine operating conditions and over the machine lifetime in order to
make this technology commercially viable. An accurate plant model for AMB
systems is essential for the aggressive design of control systems. In this
paper, we propose two approaches to obtain accurate AMB plant models for
the purpose of control design: physical modelling and system
identification. The former derives a model based upon the underlying
physical principles. The latter uses input -- output data
without explicitly resorting to physical principles. For each problem, a
brief summary of the theoretical derivation and assumptions is given.
Experimental results based on data collected from an AMB test facility at
the United Technologies Research Center provide a vehicle for a comparison
of the two approaches.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 125-142
Issue: 2
Volume: 13
Year: 2007
Month: 4
X-DOI: 10.1080/13873950600605250
File-URL: http://hdl.handle.net/10.1080/13873950600605250
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:2:p:125-142
Template-Type: ReDIF-Article 1.0
Author-Name: Kjell Hausken
Author-X-Name-First: Kjell
Author-X-Name-Last: Hausken
Author-Name: John F. Moxnes
Author-X-Name-First: John F.
Author-X-Name-Last: Moxnes
Title: The dynamics of war between benign cells, malignant cells, and killer agents
Abstract:
This article provides a dynamic description of the
interaction modelled as war between malignant cells (cancer), benign
cells, and killer agents. Killer agents are, firstly, killer cells
generated by the immune system and, secondly, chemotherapy, X-ray
treatment, laser treatment, radiotherapy, surgery, etc. We allow killer
cells to be generated proportionally to the number of benign cells, or
proportionally to the number of malignant cells. Killer cells attack only
the malignant cells, and can do so in a non-targeting or targeting manner.
The equations for non-targeting and targeting interaction are shown to be
equivalent, though with different interpretations of the terms. The killer
agents due to chemotherapy and X-ray treatment are assumed to be
non-targeting. We show that equilibrium between benign and malignant cells
is possible in living tissue. Suitably adjusting the mitosis ratio or the
death ratio for benign and malignant cells, and various other parameters,
the article demonstrates mathematically and by simulations the dynamics by
which malignant cells can be completely removed through the introduction
of killer agents.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 143-161
Issue: 2
Volume: 13
Year: 2007
Month: 4
X-DOI: 10.1080/13873950600621810
File-URL: http://hdl.handle.net/10.1080/13873950600621810
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:2:p:143-161
Template-Type: ReDIF-Article 1.0
Author-Name: Mainul Haque
Author-X-Name-First: Mainul
Author-X-Name-Last: Haque
Author-Name: Joydev Chattopadhyay
Author-X-Name-First: Joydev
Author-X-Name-Last: Chattopadhyay
Title: Role of transmissible disease in an infected prey-dependent predator -- prey system
Abstract:
The role of disease in ecological systems is a very important
issue from both mathematical and ecological points of view. This paper
deals with the qualitative analysis of a prey-dependent
predator -- prey system in which a disease is spreading among
the prey species only. We have analysed the behaviour of the system around
each equilibrium and obtained conditions for global stability of the
system around an equilibrium by using suitable Lypunov functions. We have
also worked out the region of parametric space under which the system
enters a Hopf bifurcation and a transcritical bifurcation but does not
experience either saddle-node bifurcations or pitchfork bifurcations
around the disease-free equilibrium E
2. Finally, we have given an example of a real ecological
situation with experimental data simulations.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 163-178
Issue: 2
Volume: 13
Year: 2007
Month: 4
X-DOI: 10.1080/13873950600682580
File-URL: http://hdl.handle.net/10.1080/13873950600682580
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:2:p:163-178
Template-Type: ReDIF-Article 1.0
Author-Name: Éva Gyurkovics
Author-X-Name-First: Éva
Author-X-Name-Last: Gyurkovics
Author-Name: Dietmar Meyer
Author-X-Name-First: Dietmar
Author-X-Name-Last: Meyer
Author-Name: Tibor Takács
Author-X-Name-First: Tibor
Author-X-Name-Last: Takács
Title: Budget balancing in a two-dimensional macroeconomic model
Abstract:
A two-person nonlinear dynamic game is presented to model the
government's strategy to decrease the budget deficit, where Player 1 is
the government using fiscal control and Player 2 represents the private
sector. In our macroeconomic model the growth rate of the labour force is
not known, but its lower and upper bounds are given a
priori. This means that the system is uncertain, which makes the
determination of an optimal solution (in a Nash, Stackelberg, etc. sense)
impossible. Therefore, only a guaranteeing cost control is determined for
Player 1. It is shown that the balancing by a guaranteeing cost control is
possible even in the most unfavourable situation, when the governmental
debt is higher and the volume of fixed capital stock is lower than the
equilibrium value.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 179-192
Issue: 2
Volume: 13
Year: 2007
Month: 4
X-DOI: 10.1080/13873950600739034
File-URL: http://hdl.handle.net/10.1080/13873950600739034
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:2:p:179-192
Template-Type: ReDIF-Article 1.0
Author-Name: Klaus Röbenack
Author-X-Name-First: Klaus
Author-X-Name-Last: Röbenack
Title: Controller design for nonlinear multi-input -- multi-output systems based on an algorithmic plant description
Abstract:
Complicated multi-domain systems are usually described in
terms of modelling languages. These models are mainly used for simulation.
We discuss the usage of an algorithmic plant description for nonlinear
controller design based on differential geometric concepts. The design
procedures themselves are often formulated in terms of Lie derivatives.
These derivatives are typically computed symbolically. The symbolic
manipulations require an explicit description of the plant by formulae and
expressions. Moreover, the symbolic computations can be very time
consuming for complex and large-scale systems. These problems can be
circumvented by automatic differentiation. This paper is concerned with
the controller design of algorithmically modelled plants utilizing
automatic differentiation.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 193-209
Issue: 2
Volume: 13
Year: 2007
Month: 4
X-DOI: 10.1080/13873950600621851
File-URL: http://hdl.handle.net/10.1080/13873950600621851
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:2:p:193-209
Template-Type: ReDIF-Article 1.0
Author-Name: Francesco Schiavo
Author-X-Name-First: Francesco
Author-X-Name-Last: Schiavo
Author-Name: Francesco Casella
Author-X-Name-First: Francesco
Author-X-Name-Last: Casella
Title: Object-oriented modelling and simulation of heat exchangers with finite element methods
Abstract:
The paper describes the derivation of finite-element models
of one-dimensional fluid flows with heat transfer in pipes, using the
Galerkin/least-squares approach. The models are first derived for
one-phase flows, and then extended to homogeneous two-phase flows. The
resulting equations have then been embedded in the context of
object-oriented system modelling; this allows one to combine the fluid
flow model with a model for other phenomena such as heat transfer, as well
as with models of other discrete components such as pumps or valves, to
obtain complex models of heat exchangers. The models are then validated by
simulating a typical heat exchanger plant.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 211-235
Issue: 3
Volume: 13
Year: 2007
Month: 6
X-DOI: 10.1080/13873950600821766
File-URL: http://hdl.handle.net/10.1080/13873950600821766
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:3:p:211-235
Template-Type: ReDIF-Article 1.0
Author-Name: Bong-Choon Jang
Author-X-Name-First: Bong-Choon
Author-X-Name-Last: Jang
Author-Name: Gyoojae Choi
Author-X-Name-First: Gyoojae
Author-X-Name-Last: Choi
Title: Co-simulation and simulation integration for a full vehicle dynamic system
Abstract:
The electric power steering (EPS) mechanism ensures improved
vehicle safety and fuel economy. The development of a concurrent
simulation technique and a simulation integration technique for analysing
an EPS control system with a dynamic vehicle system is described in this
paper. A full vehicle model interacting with an EPS control algorithm was
concurrently simulated on a single-bump road condition. The dynamic
responses of the vehicle chassis and the steering system resulting from
impact with the road surface were evaluated and compared with experimental
data obtained at the proving ground. Reasonable agreement was obtained for
tie-rod load, rack displacement, steering wheel torque, and tyre centre
acceleration. The concurrent simulation capability was employed for EPS
performance evaluation and calibration as well as for vehicle-handling
performance integration and synthesis.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 237-250
Issue: 3
Volume: 13
Year: 2007
Month: 6
X-DOI: 10.1080/13873950600759073
File-URL: http://hdl.handle.net/10.1080/13873950600759073
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:3:p:237-250
Template-Type: ReDIF-Article 1.0
Author-Name: G. Rigatos
Author-X-Name-First: G.
Author-X-Name-Last: Rigatos
Author-Name: S. Tzafestas
Author-X-Name-First: S.
Author-X-Name-Last: Tzafestas
Title: Extended Kalman filtering for fuzzy modelling and multi-sensor fusion
Abstract:
Extended Kalman Filtering (EKF) is proposed for: (i) the
extraction of a fuzzy model from numerical data; and (ii) the localization
of an autonomous vehicle. In the first case, the EKF algorithm is compared
to the Gauss--Newton nonlinear least-squares method and is shown to be
faster. An analysis of the EKF convergence is given. In the second case,
the EKF algorithm estimates the state vector of the autonomous vehicle by
fusing data coming from odometric sensors and sonars. Simulation tests
show that the accuracy of the EKF-based vehicle localization is
satisfactory.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 251-266
Issue: 3
Volume: 13
Year: 2007
Month: 6
X-DOI: 10.1080/01443610500212468
File-URL: http://hdl.handle.net/10.1080/01443610500212468
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:3:p:251-266
Template-Type: ReDIF-Article 1.0
Author-Name: D. Gradišar
Author-X-Name-First: D.
Author-X-Name-Last: Gradišar
Author-Name: G. Mušič
Author-X-Name-First: G.
Author-X-Name-Last: Mušič
Title: Automated Petri-net modelling based on production management data
Abstract:
Timed Petri nets can be used for the modelling and analysis
of a wide range of concurrent discrete-event systems, e.g. production
systems. The present paper describes how to do so while starting from the
information about the structure of a production facility and about the
products usually given in production-data management systems. We describe
a method for using these data to algorithmically build a Petri-net model.
The timed Petri-net simulator, which was built in Matlab®, is also
described. This simulator makes it possible to introduce heuristics, and
in this way production operations can be scheduled. To demonstrate the
applicability of our approach, we applied it to a scheduling problem in a
multi-product batch plant.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 267-290
Issue: 3
Volume: 13
Year: 2007
Month: 6
X-DOI: 10.1080/13873950600834082
File-URL: http://hdl.handle.net/10.1080/13873950600834082
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:3:p:267-290
Template-Type: ReDIF-Article 1.0
Author-Name: Roswitha März
Author-X-Name-First: Roswitha
Author-X-Name-Last: März
Author-Name: Ricardo Riaza
Author-X-Name-First: Ricardo
Author-X-Name-Last: Riaza
Title: Linear differential-algebraic equations with properly stated leading term: A-critical points
Abstract:
Time-domain models of dynamical systems are formulated in
many applications in terms of differential-algebraic equations (DAEs). In
the linear time-varying context, certain limitations of models of the form
E(t)x′(t
) + B(t)x(t) = q(t) have recently led to the properly stated formulation
A(t)(D(t)x(t))′ + B(t)x(t) =&#
xA0;q(t), which allows for explicit
descriptions of problem solutions in regular DAEs with arbitrary index,
and provides precise functional input-output characterizations of the
system. In this context, the present paper addresses critical points of
linear DAEs with properly stated leading term; such critical points
describe different types of singularities in the system. Critical points
are classified according to a taxonomy which reflects the phenomenon from
which the singularity stems; this taxonomy is proved independent of
projectors and also invariant under linear time-varying coordinate changes
and refactorizations. Under certain working assumptions, the analysis of
such critical problems can be carried out through a scalarly
implicit decoupling, yielding a singular inherent ODE. Certain
harmless problems for which this decoupling can be rewritten in explicit
form are characterized. Some electrical circuit applications, including a
linear time-varying analogue of Chua's circuit, are discussed for
illustrative purposes.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 291-314
Issue: 3
Volume: 13
Year: 2007
Month: 6
X-DOI: 10.1080/13873950600883428
File-URL: http://hdl.handle.net/10.1080/13873950600883428
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:3:p:291-314
Template-Type: ReDIF-Article 1.0
Author-Name: Roland Pulch
Author-X-Name-First: Roland
Author-X-Name-Last: Pulch
Title: Multidimensional models for analysing frequency modulated signals
Abstract:
In radio frequency (RF) applications, slowly varying signals
often modulate the amplitude and frequency of fast carrier waves. Thus a
numerical simulation of the differential algebraic equations (DAEs)
modelling the electric circuit becomes tedious. Alternative models are
required to achieve efficient simulations. A multivariate formulation of
signals yields a suitable representation via decoupling the widely
separated time scales. Consequently, the circuit's DAEs change into warped
multirate partial DAEs. On the other hand, the transient behaviour of the
circuit can also be approximated by a parameter-dependent DAE model
including a multivariate structure. The properties of this alternative
strategy are investigated. In particular, the two multidimensional
approaches are compared with respect to the simulation of RF signals.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 315-330
Issue: 4
Volume: 13
Year: 2007
Month: 8
X-DOI: 10.1080/13873950600994506
File-URL: http://hdl.handle.net/10.1080/13873950600994506
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:4:p:315-330
Template-Type: ReDIF-Article 1.0
Author-Name: I. Lebar Bajec
Author-X-Name-First: I. Lebar
Author-X-Name-Last: Bajec
Author-Name: N. Zimic
Author-X-Name-First: N.
Author-X-Name-Last: Zimic
Author-Name: M. Mraz
Author-X-Name-First: M.
Author-X-Name-Last: Mraz
Title: The computational beauty of flocking: boids revisited
Abstract:
Artificial-life research was founded in the mid-1980s. It
promotes the idea of the bottom-up research approach, where only the basic
units of a situation and their local interaction are modelled, and then
the system is left to evolve. However, the notable progress of the
processing power of personal computers, evident in the last two decades,
has had little influence on the ways the basic units (artificial animals
or animats) are constructed. This impacts largely on the applicability of
the methods in other research fields. Our field of choice is the modelling
of bird flocks. This area was at its peak in the late 1980s when Craig W.
Reynolds presented the first and most influential model -- the
boids. In spite of his many following works no formal definition has ever
been presented. This might be the reason why a second generation of
flocking models is still awaited. In this article we make a step forward,
all in view of allowing for the development of the second-generation
models. We present an artificial animal construction framework that has
been obtained as a generalization of the existing bird flocking models,
but is not limited to them. The article thus presents a formal definition
of the framework and gives an example of its use. In the latter the
framework is employed to present a formalization of Reynolds's boids.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 331-347
Issue: 4
Volume: 13
Year: 2007
Month: 8
X-DOI: 10.1080/13873950600883485
File-URL: http://hdl.handle.net/10.1080/13873950600883485
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:4:p:331-347
Template-Type: ReDIF-Article 1.0
Author-Name: Bernd Möller
Author-X-Name-First: Bernd
Author-X-Name-Last: Möller
Author-Name: Wolfgang Graf
Author-X-Name-First: Wolfgang
Author-X-Name-Last: Graf
Author-Name: Jan-Uwe Sickert
Author-X-Name-First: Jan-Uwe
Author-X-Name-Last: Sickert
Author-Name: Uwe Reuter
Author-X-Name-First: Uwe
Author-X-Name-Last: Reuter
Title: Numerical simulation based on fuzzy stochastic analysis
Abstract:
In this paper mathematical methods for fuzzy stochastic
analysis in engineering applications are presented. Fuzzy stochastic
analysis maps uncertain input data in the form of fuzzy random variables
onto fuzzy random result variables. The operator of the mapping can be any
desired deterministic algorithm, e.g. the dynamic analysis of structures.
Two different approaches for processing the fuzzy random input data are
discussed. For these purposes two types of fuzzy probability distribution
functions for describing fuzzy random variables are introduced. On the
basis of these two types of fuzzy probability distribution functions two
appropriate algorithms for fuzzy stochastic analysis are developed. Both
algorithms are demonstrated and compared by way of an example.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 349-364
Issue: 4
Volume: 13
Year: 2007
Month: 8
X-DOI: 10.1080/13873950600994514
File-URL: http://hdl.handle.net/10.1080/13873950600994514
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:4:p:349-364
Template-Type: ReDIF-Article 1.0
Author-Name: Tarek Ahmed-Ali
Author-X-Name-First: Tarek
Author-X-Name-Last: Ahmed-Ali
Author-Name: Godpromesse Kenné
Author-X-Name-First: Godpromesse
Author-X-Name-Last: Kenné
Author-Name: Françoise Lamnabhi-Lagarrigue
Author-X-Name-First: Françoise
Author-X-Name-Last: Lamnabhi-Lagarrigue
Title: Nonlinear systems parameter estimation using neural networks: Application to synchronous machines
Abstract:
This paper is devoted to state and parameter estimation for a
large class of nonlinear systems using a radial basis function neural
network predictor in the continuous time domain. The proof of the
convergence of the estimates to their true values is achieved using
Lyapunov theories and does not require the classical persistent excitation
condition to be satisfied by the input signal. Comparisons between the
results obtained and those of the method based on the sliding mode
observer are also presented in the case of the estimation of the
synchronous machine inductance parameters. The performance exhibited by
the obtained results demonstrate that the proposed scheme can also work
very well if the stator resistance varies due to the stator winding
heating. The comparative results show globally that the proposed algorithm
gives better performance than the method based on the sliding mode
observer in terms of the convergence rate and the state/parameter
accuracies.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 365-382
Issue: 4
Volume: 13
Year: 2007
Month: 8
X-DOI: 10.1080/13873950600913787
File-URL: http://hdl.handle.net/10.1080/13873950600913787
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:4:p:365-382
Template-Type: ReDIF-Article 1.0
Author-Name: Georg Denk
Author-X-Name-First: Georg
Author-X-Name-Last: Denk
Author-Name: Renate Winkler
Author-X-Name-First: Renate
Author-X-Name-Last: Winkler
Title: Modelling and simulation of transient noise in circuit simulation
Abstract:
Abstract This paper presents a new
approach to the transient noise analysis of integrated circuits. This
approach consists of two parts, the modelling of noise sources in the time
domain and the development of numerical schemes for stochastic
differential-algebraic equations. The noise sources include thermal noise,
shot noise, and flicker noise and their modelling is based on generalized
stochastic processes. Brownian motion is the starting point for the
modelling of white-noise sources (thermal and shot noise), while
fractional Brownian motion is used for flicker noise sources. The
numerical schemes employed for the computation of solution paths adapt
well-known methods for stochastic differential equations to the specific
situation within circuit simulation. Under the assumption of small noise
the convergence properties of the drift-implicit Euler scheme and the
drift-implicit Milstein scheme are proved. Finally numerical experiments
with real-world circuits are presented.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 383-394
Issue: 4
Volume: 13
Year: 2007
Month: 8
X-DOI: 10.1080/13873950500064400
File-URL: http://hdl.handle.net/10.1080/13873950500064400
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:4:p:383-394
Template-Type: ReDIF-Article 1.0
Author-Name: D. A. Vaccari
Author-X-Name-First: D. A.
Author-X-Name-Last: Vaccari
Author-Name: H. -K. Wang
Author-X-Name-First: H. -K.
Author-X-Name-Last: Wang
Title: Multivariate polynomial regression for identification of chaotic time series
Abstract:
Multivariate polynomial regression was used to generate
polynomial iterators for time series exhibiting autocorrelations. A
stepwise technique was used to add and remove polynomial terms to ensure
the model contained only those terms that produce a statistically
significant contribution to the fit. An approach is described in which
datasets are divided into three subsets for identification, estimation,
and validation. This produces a parsimonious global model that is can
greatly reduce the tendency towards undesirable behaviours such as
overfitting or instability. The technique was found to be able to identify
the nonlinear dynamic behaviour of simulated time series, as reflected in
the geometry of the attractor and calculation of multiple Lyapunov
exponents, even in noisy systems. The technique was applied to
times series data obtained from simulations of the Lorenz and
Mackey -- Glass equations with and without measurement noise.
The model was also used to determine the embedding dimension of the
Mackey -- Glass equation.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 395-412
Issue: 4
Volume: 13
Year: 2007
Month: 8
X-DOI: 10.1080/13873950600883691
File-URL: http://hdl.handle.net/10.1080/13873950600883691
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:4:p:395-412
Template-Type: ReDIF-Article 1.0
Author-Name: Timo Reis
Author-X-Name-First: Timo
Author-X-Name-Last: Reis
Author-Name: Tatjana Stykel
Author-X-Name-First: Tatjana
Author-X-Name-Last: Stykel
Title: Stability analysis and model order reduction of coupled systems
Abstract:
In this paper we discuss the stability and model order
reduction of coupled linear time-invariant descriptor systems. Sufficient
conditions for the asymptotic stability of a closed-loop system are given.
We present a model reduction approach for coupled systems based on
reducing the order of the subsystems and coupling the reduced-order models
through the same interconnection relations as for the original system.
Such an approach allows us to obtain error bounds for the reduced-order
closed-loop system in terms of the errors in the reduced-order subsystems.
Model reduction of coupled systems with unstable or improper subsystems is
also considered. Numerical examples are given.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 413-436
Issue: 5
Volume: 13
Year: 2007
Month: 10
X-DOI: 10.1080/13873950701189071
File-URL: http://hdl.handle.net/10.1080/13873950701189071
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:5:p:413-436
Template-Type: ReDIF-Article 1.0
Author-Name: Linghai Lu
Author-X-Name-First: Linghai
Author-X-Name-Last: Lu
Author-Name: D. J. Murray-Smith
Author-X-Name-First: D. J.
Author-X-Name-Last: Murray-Smith
Author-Name: E. W. McGookin
Author-X-Name-First: E. W.
Author-X-Name-Last: McGookin
Title: Investigation of inverse simulation for design of feedforward controllers
Abstract:
This paper describes the use of inverse simulation to develop
feedforward controllers for model-based output-tracking control system
structures, thus avoiding the more complicated techniques of model
inversion. Similarities and shortcomings of the inverse simulation and
model inversion approaches are explored. It is found that, with suitable
values of discretized time interval, the method based on inverse
simulation may be preferable for minimum-phase systems. Depending upon
zero redistribution within the process of inverse simulation,
non-minimum-phase problems for linear systems can also be handled. The
conclusions are demonstrated using a non-linear HS125 aircraft model, a
linearised Lynx helicopter model and a container ship model for ship
steering control and roll stabilization.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 437-454
Issue: 5
Volume: 13
Year: 2007
Month: 10
X-DOI: 10.1080/13873950701344023
File-URL: http://hdl.handle.net/10.1080/13873950701344023
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:5:p:437-454
Template-Type: ReDIF-Article 1.0
Author-Name: Carsten Collon
Author-X-Name-First: Carsten
Author-X-Name-Last: Collon
Author-Name: Stephan Eckhardt
Author-X-Name-First: Stephan
Author-X-Name-Last: Eckhardt
Author-Name: Joachim Rudolph
Author-X-Name-First: Joachim
Author-X-Name-Last: Rudolph
Title: A network approach to the modelling of active magnetic bearings
Abstract:
The modelling of active magnetic bearings based on a network
approach is considered. Unlike in the standard modelling approach, where a
linearization of the current-force relation for the centred shaft position
is used, network models permit to include the position dependence of the
bearing force in the force model. This becomes necessary when model based
controllers are used to stabilize a magnetically supported shaft in
tracking applications. The approach is based on the well known
application of network models to magnetic circuits. Further simplifying
assumptions are discussed which allow one to obtain a network with a
limited number of lumped parameters describing the magnetic behaviour of a
magnetic bearing. The modelling of a combined radial and axial bearing
serves as an example for the application of the proposed approach.
Furthermore, the fitting of the network based model to measured
characteristic force curves is discussed. In this context, a method for
including saturation effects in the model is sketched.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 455-469
Issue: 5
Volume: 13
Year: 2007
Month: 10
X-DOI: 10.1080/13873950701189055
File-URL: http://hdl.handle.net/10.1080/13873950701189055
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:5:p:455-469
Template-Type: ReDIF-Article 1.0
Author-Name: K. Sternberg
Author-X-Name-First: K.
Author-X-Name-Last: Sternberg
Author-Name: K. Chudej
Author-X-Name-First: K.
Author-X-Name-Last: Chudej
Author-Name: H. J. Pesch
Author-X-Name-First: H. J.
Author-X-Name-Last: Pesch
Title: Suboptimal control of a 2D molten carbonate fuel cell PDAE model
Abstract:
Numerical results for suboptimal boundary control of an
integro partial differential algebraic equation system of dimension 28 are
presented. The application is a molten carbonate fuel cell power plant.
The technically and economically important fast tracking of the new
stationary cell voltage during a load change is optimized. The nonstandard
optimal control problem s.t. degenerated PDE is discretized by the method
of lines yielding a very large DAE constrained standard optimal control
problem. An index analysis is performed to identify consistent initial
conditions.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 471-485
Issue: 5
Volume: 13
Year: 2007
Month: 10
X-DOI: 10.1080/13873950701377288
File-URL: http://hdl.handle.net/10.1080/13873950701377288
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:5:p:471-485
Template-Type: ReDIF-Article 1.0
Author-Name: O. Slaby
Author-X-Name-First: O.
Author-X-Name-Last: Slaby
Author-Name: S. Sager
Author-X-Name-First: S.
Author-X-Name-Last: Sager
Author-Name: O. S. Shaik
Author-X-Name-First: O. S.
Author-X-Name-Last: Shaik
Author-Name: U. Kummer
Author-X-Name-First: U.
Author-X-Name-Last: Kummer
Author-Name: D. Lebiedz
Author-X-Name-First: D.
Author-X-Name-Last: Lebiedz
Title: Optimal control of self-organized dynamics in cellular signal transduction
Abstract:
We demonstrate how model-based optimal control can be
exploited in biological and biochemical modelling applications in several
ways. In the first part, we apply optimal control to a detailed kinetic
model of a glycolysis oscillator, which plays a central role in immune
cells, in order to analyse potential regulatory mechanisms in the dynamics
of associated signalling pathways. We demonstrate that the formulation of
inverse problems with the aim to determine specific time-dependent input
stimuli can provide important insight into dynamic regulations of
self-organized cellular signal transduction. In the second part, we
present an optimal control study aimed at target-oriented manipulation of
a biological rhythm, an internal clock mechanism related to the circadian
oscillator. This oscillator is responsible for the approximate endogenous
24 h (latin: circa dies) day-night rhythm in many organisms. On the
basis of a kinetic model for the fruit fly Drosophila, we compute
switching light stimuli via mixed-integer optimal control that annihilate
the oscillations for a fixed time interval. Insight gained from such
model-based specific manipulation may be promising in biomedical
applications.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 487-502
Issue: 5
Volume: 13
Year: 2007
Month: 10
X-DOI: 10.1080/13873950701243969
File-URL: http://hdl.handle.net/10.1080/13873950701243969
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:5:p:487-502
Template-Type: ReDIF-Article 1.0
Author-Name: Denis Dochain
Author-X-Name-First: Denis
Author-X-Name-Last: Dochain
Title: Editorial
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 1-1
Issue: 1
Volume: 14
Year: 2008
Month: 2
X-DOI: 10.1080/13873950701722822
File-URL: http://hdl.handle.net/10.1080/13873950701722822
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:14:y:2008:i:1:p:1-1
Template-Type: ReDIF-Article 1.0
Author-Name: H. Fibrianto
Author-X-Name-First: H.
Author-X-Name-Last: Fibrianto
Author-Name: D. Mazouni
Author-X-Name-First: D.
Author-X-Name-Last: Mazouni
Author-Name: M. Ignatova
Author-X-Name-First: M.
Author-X-Name-Last: Ignatova
Author-Name: M. Herveau
Author-X-Name-First: M.
Author-X-Name-Last: Herveau
Author-Name: J. Harmand
Author-X-Name-First: J.
Author-X-Name-Last: Harmand
Author-Name: D. Dochain
Author-X-Name-First: D.
Author-X-Name-Last: Dochain
Title: Dynamical modelling, identification and software sensors for SBRs
Abstract:
This paper presents the two models, called EM1 and EM2,
obtained for the two process configurations considered within the EOLI
project. It also gives results of software sensors based on these models
to provide on-line estimates of unmeasured process variables, and for
which the design has considered in particular uncertainty on the model
parameters.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 17-26
Issue: 1
Volume: 14
Year: 2007
Month: 5
X-DOI: 10.1080/13873950701723176
File-URL: http://hdl.handle.net/10.1080/13873950701723176
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:1:p:17-26
Template-Type: ReDIF-Article 1.0
Author-Name: Roberto Canziani
Author-X-Name-First: Roberto
Author-X-Name-Last: Canziani
Author-Name: Elena Ficara
Author-X-Name-First: Elena
Author-X-Name-Last: Ficara
Author-Name: Nicola Fiocchi
Author-X-Name-First: Nicola
Author-X-Name-Last: Fiocchi
Author-Name: Paolo Ratini
Author-X-Name-First: Paolo
Author-X-Name-Last: Ratini
Author-Name: Massimiliano Pirani
Author-X-Name-First: Massimiliano
Author-X-Name-Last: Pirani
Author-Name: Simone Mariani
Author-X-Name-First: Simone
Author-X-Name-Last: Mariani
Author-Name: Meriem Bekri
Author-X-Name-First: Meriem
Author-X-Name-Last: Bekri
Author-Name: André Pauss
Author-X-Name-First: André
Author-X-Name-Last: Pauss
Author-Name: Thierry Ribeiro
Author-X-Name-First: Thierry
Author-X-Name-Last: Ribeiro
Author-Name: Olivier Schoefs
Author-X-Name-First: Olivier
Author-X-Name-Last: Schoefs
Author-Name: Jean-Claude Bouvier
Author-X-Name-First: Jean-Claude
Author-X-Name-Last: Bouvier
Author-Name: Jérôme Harmand
Author-X-Name-First: Jérôme
Author-X-Name-Last: Harmand
Author-Name: Djalel Mazouni
Author-X-Name-First: Djalel
Author-X-Name-Last: Mazouni
Title: Development of hardware sensors for the online monitoring of SBR used for the treatment of industrial wastewaters
Abstract:
The main challenge in the management of a sequencing batch
reactor, for the biological treatment of urban and industrial wastewaters,
is to ensure stable treatment efficiency under highly variable influent
quality and quantity. To cope with this challenge, online instrumentation
is fundamental, since it allows to characterize both influent variability
and process efficiency. The more the online data are closely correlated
with influent quality and SBRs treatment capacity, the more
straightforward is the implementation of control strategies based on these
data. In this paper, two monitoring techniques are described, which allow
to obtain influent-related and process-related data: set-point titration
and UV spectrophotometry. Despite the very different measuring principles,
both techniques were successfully applied to SBRs monitoring and control
leading to comparable results.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 27-37
Issue: 1
Volume: 14
Year: 2007
Month: 5
X-DOI: 10.1080/13873950701723291
File-URL: http://hdl.handle.net/10.1080/13873950701723291
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:1:p:27-37
Template-Type: ReDIF-Article 1.0
Author-Name: G. Buitrón
Author-X-Name-First: G.
Author-X-Name-Last: Buitrón
Author-Name: R. Canziani
Author-X-Name-First: R.
Author-X-Name-Last: Canziani
Author-Name: M. Torrijos
Author-X-Name-First: M.
Author-X-Name-Last: Torrijos
Author-Name: S. Gutiérrez
Author-X-Name-First: S.
Author-X-Name-Last: Gutiérrez
Author-Name: I. Moreno-Andrade
Author-X-Name-First: I.
Author-X-Name-Last: Moreno-Andrade
Author-Name: D. Mazouni
Author-X-Name-First: D.
Author-X-Name-Last: Mazouni
Author-Name: N. Fiocchi
Author-X-Name-First: N.
Author-X-Name-Last: Fiocchi
Author-Name: E. Ficara
Author-X-Name-First: E.
Author-X-Name-Last: Ficara
Author-Name: G. Moreno
Author-X-Name-First: G.
Author-X-Name-Last: Moreno
Author-Name: A. Benitez
Author-X-Name-First: A.
Author-X-Name-Last: Benitez
Author-Name: J. Pérez
Author-X-Name-First: J.
Author-X-Name-Last: Pérez
Author-Name: A. Ferrari
Author-X-Name-First: A.
Author-X-Name-Last: Ferrari
Title: Experiments for modelling the biodegradation of wastewater in sequencing batch reactors
Abstract:
Three types of wastewater were considered: typical municipal
wastewater and the effluent of a dairy industry, both polluted with
organic carbon and nitrogen, and wastewater typical of a chemical
industry, containing toxic or recalcitrant compounds (4-chlorophenol).
Sequencing batch reactors (SBRs) were considered. Process experiments were
performed to provide experimental data for parameter identification of the
dynamical models of the SBRs. The processes were instrumented with sensors
to measure O2, NH3, T, pH, OUR, and other off line
measurements (e.g.: NO2 -super-− and
NO3 -super-−, COD, phenol concentration,
microbiological counts and activities) in order to study more accurately
the behaviour of the biomasses. However, the general idea is to design a
system with a minimal number of sensors.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 3-15
Issue: 1
Volume: 14
Year: 2007
Month: 5
X-DOI: 10.1080/13873950701723077
File-URL: http://hdl.handle.net/10.1080/13873950701723077
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:1:p:3-15
Template-Type: ReDIF-Article 1.0
Author-Name: M. J. Betancur
Author-X-Name-First: M. J.
Author-X-Name-Last: Betancur
Author-Name: D. Mazouni
Author-X-Name-First: D.
Author-X-Name-Last: Mazouni
Author-Name: J. A. Moreno
Author-X-Name-First: J. A.
Author-X-Name-Last: Moreno
Author-Name: J. Harmand
Author-X-Name-First: J.
Author-X-Name-Last: Harmand
Title: Optimal control of biological SBRs for the treatment of dairy and toxic wastewaters
Abstract:
This paper presents two optimal control strategies developed
for the control of two biological sequencing batch reactors (SBR), the
first one performing both organic carbon and nitrogen removal from dairy
wastewaters, while the second one treats toxic wastewaters. The proposed
control laws are based on models that have been validated with real data
acquired on two real biological SBR pilot plants. These models are
presented in D. Mazouni et al., 16th IFAC World Congress,
Prague, 5--8 July 2005. The validation results of these control strategies
are presented and discussed.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 39-52
Issue: 1
Volume: 14
Year: 2007
Month: 5
X-DOI: 10.1080/13873950701723408
File-URL: http://hdl.handle.net/10.1080/13873950701723408
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:1:p:39-52
Template-Type: ReDIF-Article 1.0
Author-Name: D. Wimberger
Author-X-Name-First: D.
Author-X-Name-Last: Wimberger
Author-Name: C. Verde R.
Author-X-Name-First: C.
Author-X-Name-Last: Verde R.
Title: Diagnosis of abnormal conditions of an aerobic SBR process
Abstract:
Process fault diagnosis (PFD) allows a control system to
maintain the operation of a process under the presence of faults. This is
a critical feature for a discontinuous activated sludge waste water
treatment (WWT) process in a sequencing batch reactor (SBR), treating
waste water contaminated with organic toxic compounds. Here, a methodology
for diagnosis based on the extraction of characteristics from the
respiration signal, a known indicator for biological activity in aerobic
WWT processes, and their classification is proposed. The usefulness of the
signal for the detection and classification of a set of defined abnormal
conditions was verified through sensitivity analysis. The analysis not
only shows the effects of parameter deviations but also indicates the
characteristics to be extracted from the respiration signal for a
successful classification. Results obtained by simulation indicate that
the signal based PFD can successfully cope with uncertainties common in
this type of bioprocesses, which prevent the straightforward application
of analytical PFD approaches.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 53-66
Issue: 1
Volume: 14
Year: 2007
Month: 5
X-DOI: 10.1080/13873950701723432
File-URL: http://hdl.handle.net/10.1080/13873950701723432
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:1:p:53-66
Template-Type: ReDIF-Article 1.0
Author-Name: P. Ratini
Author-X-Name-First: P.
Author-X-Name-Last: Ratini
Author-Name: M. Pirani
Author-X-Name-First: M.
Author-X-Name-Last: Pirani
Author-Name: S. Mariani
Author-X-Name-First: S.
Author-X-Name-Last: Mariani
Author-Name: A. Quintabà
Author-X-Name-First: A.
Author-X-Name-Last: Quintabà
Author-Name: L. Luccarini
Author-X-Name-First: L.
Author-X-Name-Last: Luccarini
Author-Name: D. Mazouni
Author-X-Name-First: D.
Author-X-Name-Last: Mazouni
Author-Name: N. Fiocchi
Author-X-Name-First: N.
Author-X-Name-Last: Fiocchi
Author-Name: J. Harmand
Author-X-Name-First: J.
Author-X-Name-Last: Harmand
Title: Development of an integrated system for the optimization of sequencing batch reactors
Abstract:
This paper presents (i) a synthesis of the EOLI supervision
system for optimizing both the biological reaction phases and the settling
phase of Sequencing Batch Reactors (SBR) performing carbon and nitrogen
removal from urban or industrial wastewaters; (ii) a summary of the
integration capabilities of the integrated system developed by an
industrial partner of the project to propose both the hardware and the
software of the EOLI solution under a unified framework.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 67-78
Issue: 1
Volume: 14
Year: 2007
Month: 5
X-DOI: 10.1080/13873950701723457
File-URL: http://hdl.handle.net/10.1080/13873950701723457
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:1:p:67-78
Template-Type: ReDIF-Article 1.0
Author-Name: T. Schmickl
Author-X-Name-First: T.
Author-X-Name-Last: Schmickl
Author-Name: K. Crailsheim
Author-X-Name-First: K.
Author-X-Name-Last: Crailsheim
Title: TaskSelSim: a model of the self-organization of the division of labour in honeybees
Abstract:
We here describe a novel multi-agent model of the
decentralized task selection process in honeybee colonies. The model is
based on individual behavioural programs represented as hierarchical
finite state automatons. We successfully simulated empirical experiments
(with real honeybees) using the model. We shed more light on task
specialization and polyethism in honeybees by modelling the heterogeneous
environment that emerges over time inside the colony and by considering
the changing differences in stimuli strength in each small area of the
hive. Our simulation experiments presented here investigate the model's
reaction to changing values in crucial model parameters and investigate
the stability of the predicted colony behaviours.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 101-125
Issue: 2
Volume: 14
Year: 2007
Month: 8
X-DOI: 10.1080/13873950701846662
File-URL: http://hdl.handle.net/10.1080/13873950701846662
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:2:p:101-125
Template-Type: ReDIF-Article 1.0
Author-Name: Giuseppe Fusco
Author-X-Name-First: Giuseppe
Author-X-Name-Last: Fusco
Author-Name: Mario Russo
Author-X-Name-First: Mario
Author-X-Name-Last: Russo
Title: A simulation tool for voltage control studies in power systems
Abstract:
An electrical power system is a large scale system composed
of complicated and sophisticated combination of multiple electronic and
electromechanical components. In general, these components are nonlinear.
Power system is also characterized by a wide range of normal operating
conditions which continuously vary. To help the designer study the voltage
control problems in power systems, a simulation tool is presented in this
paper. It is based on decomposition of the overall system simulation task
into three subtasks so as to attain both computational efficiency and
flexibility. The use of the proposed simulation tool in a voltage control
problem is also presented.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 127-145
Issue: 2
Volume: 14
Year: 2007
Month: 1
X-DOI: 10.1080/13873950701469549
File-URL: http://hdl.handle.net/10.1080/13873950701469549
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:2:p:127-145
Template-Type: ReDIF-Article 1.0
Author-Name: A. Dhooge
Author-X-Name-First: A.
Author-X-Name-Last: Dhooge
Author-Name: W. Govaerts
Author-X-Name-First: W.
Author-X-Name-Last: Govaerts
Author-Name: Yu. A. Kuznetsov
Author-X-Name-First: Yu. A.
Author-X-Name-Last: Kuznetsov
Author-Name: H. G.E. Meijer
Author-X-Name-First: H. G.E.
Author-X-Name-Last: Meijer
Author-Name: B. Sautois
Author-X-Name-First: B.
Author-X-Name-Last: Sautois
Title: New features of the software MatCont for bifurcation analysis of dynamical systems
Abstract:
Bifurcation software is an essential tool in the study of
dynamical systems. From the beginning (the first packages were written in
the 1970's) it was also used in the modelling process, in particular to
determine the values of critical parameters. More recently, it is used in
a systematic way in the design of dynamical models and to determine which
parameters are relevant. MatCont and
Cl_MatCont are freely available matlab
numerical continuation packages for the interactive study of dynamical
systems and bifurcations. MatCont is the GUI-version,
Cl_MatCont is the command-line version. The
work started in 2000 and the first publications appeared in 2003. Since
that time many new functionalities were added. Some of these are fairly
simple but were never before implemented in continuation codes, e.g.
Poincaré maps. Others were only available as toolboxes that can be used by
experts, e.g. continuation of homoclinic orbits. Several others were never
implemented at all, such as periodic normal forms for codimension 1
bifurcations of limit cycles, normal forms for codimension 2 bifurcations
of equilibria, detection of codimension 2 bifurcations of limit cycles,
automatic computation of phase response curves and their derivatives,
continuation of branch points of equilibria and limit cycles. New
numerical algorithms for these computations have been published or will
appear elsewhere; here we restrict to their software implementation. We
further discuss software issues that are in practice important for many
users, e.g. how to define a new system starting from an existing one, how
to import and export data, system descriptions, and computed results.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 147-175
Issue: 2
Volume: 14
Year: 2007
Month: 9
X-DOI: 10.1080/13873950701742754
File-URL: http://hdl.handle.net/10.1080/13873950701742754
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:2:p:147-175
Template-Type: ReDIF-Article 1.0
Author-Name: F. Donida
Author-X-Name-First: F.
Author-X-Name-Last: Donida
Author-Name: G. Ferretti
Author-X-Name-First: G.
Author-X-Name-Last: Ferretti
Author-Name: S. M. Savaresi
Author-X-Name-First: S. M.
Author-X-Name-Last: Savaresi
Author-Name: M. Tanelli
Author-X-Name-First: M.
Author-X-Name-Last: Tanelli
Title: Object-oriented modelling and simulation of a motorcycle
Abstract:
The design of a control oriented motorcycle model for the
simulation of two-wheeled vehicles is widely recognized to be a very
challenging task, as a complete analytical model is not directly
available, due to its complexity and its high sensitivity to parameters'
variations. Accordingly, a reliable model should be based on multibody
modelling tools endowed with automated symbolic manipulation capabilities.
This paper presents a simulation model for the dynamic behaviour of a
motorcycle based on the object-oriented modelling paradigm developed in
Modelica, within the Dymola environment. Specifically, we illustrate the
modular approach to motorcycle modelling and discuss the tire-road
interaction model, which is the crucial part of the proposed model. The
validity of the proposed simulation model is assessed on real data,
measured on an instrumented test vehicle. Further, to perform the
verification phase a virtual driver model has been implemented, which
allows to track both a roll angle and a target speed profile during
different maneuvers. In particular, the behaviour of the driver is
modelled as an inverse pendulum, with a rotational degree of freedom along
the forward axis. This allows accounting for the driver lean angle, which
is necessary to fully capture the real driving behaviour and its effects
on the overall vehicle dynamics.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 79-100
Issue: 2
Volume: 14
Year: 2007
Month: 10
X-DOI: 10.1080/13873950701847090
File-URL: http://hdl.handle.net/10.1080/13873950701847090
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:2:p:79-100
Template-Type: ReDIF-Article 1.0
Author-Name: Andreas Kugi
Author-X-Name-First: Andreas
Author-X-Name-Last: Kugi
Author-Name: Kurt Schlacher
Author-X-Name-First: Kurt
Author-X-Name-Last: Schlacher
Title: Modelling of distributed-parameter systems for control purposes
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 177-178
Issue: 3
Volume: 14
Year: 2008
Month: 6
X-DOI: 10.1080/13873950701844816
File-URL: http://hdl.handle.net/10.1080/13873950701844816
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Handle: RePEc:taf:nmcmxx:v:14:y:2008:i:3:p:177-178
Template-Type: ReDIF-Article 1.0
Author-Name: M. Schöberl
Author-X-Name-First: M.
Author-X-Name-Last: Schöberl
Author-Name: H. Ennsbrunner
Author-X-Name-First: H.
Author-X-Name-Last: Ennsbrunner
Author-Name: K. Schlacher
Author-X-Name-First: K.
Author-X-Name-Last: Schlacher
Title: Modelling of piezoelectric structures--a Hamiltonian approach
Abstract:
This contribution is dedicated to the geometric description
of infinite-dimensional port Hamiltonian systems with in- and output
operators. Several approaches exist, which deal with the extension of the
well-known lumped parameter case to the distributed one. In this article a
description has been chosen, which preserves useful properties known from
the class of port controlled Hamiltonian systems with dissipation in the
lumped scenario. Furthermore, the introduced in- and output maps are
defined by linear differential operators. The derived theory is applied to
the piezoelectric field equations to obtain their port Hamiltonian
representation. In this example, the electrical field strength is assumed
to act as distributed input. Finally it is shown, that distributed inputs,
that are in the kernel of the input map act similarly on the system as
certain boundary inputs.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 179-193
Issue: 3
Volume: 14
Year: 2007
Month: 8
X-DOI: 10.1080/13873950701844824
File-URL: http://hdl.handle.net/10.1080/13873950701844824
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:3:p:179-193
Template-Type: ReDIF-Article 1.0
Author-Name: A. Baaiu
Author-X-Name-First: A.
Author-X-Name-Last: Baaiu
Author-Name: F. Couenne
Author-X-Name-First: F.
Author-X-Name-Last: Couenne
Author-Name: Y. Le Gorrec
Author-X-Name-First: Y.
Author-X-Name-Last: Le Gorrec
Author-Name: L. Lefevre
Author-X-Name-First: L.
Author-X-Name-Last: Lefevre
Author-Name: M. Tayakout
Author-X-Name-First: M.
Author-X-Name-Last: Tayakout
Title: Port based modelling of a multiscale adsorption column
Abstract:
A port-based distributed parameter model of an adsorption
column under isothermal conditions is presented. This model is made using
bond graph terminology and basic axioms of irreversible thermodynamics.
The particularity of this model is to split each phenomenon in basic
elements with particular energetic behaviour, such as accumulation or
dissipation. These basic elements are interconnected using the port
variables and some interconnection power conserving structures, named
Dirac structures. These energetic elements are presented in terms of the
geometry of the different scales of the adsorption column. Moreover it is
shown that each scale of the model has the same bond graph structure. The
different scales of the model are also connected by a power conserving
structure.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 195-211
Issue: 3
Volume: 14
Year: 2007
Month: 8
X-DOI: 10.1080/13873950701844840
File-URL: http://hdl.handle.net/10.1080/13873950701844840
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:3:p:195-211
Template-Type: ReDIF-Article 1.0
Author-Name: T. Meurer
Author-X-Name-First: T.
Author-X-Name-Last: Meurer
Author-Name: M. Zeitz
Author-X-Name-First: M.
Author-X-Name-Last: Zeitz
Title: Model inversion of boundary controlled parabolic partial differential equations using summability methods
Abstract:
The combination of formal power series and appropriate
summability methods is considered for the inversion of the non-linear,
distributed-parameter model of a boundary controlled tubular reactor. The
inversion is performed in order to realize the tracking of certain
prescribed output trajectories in open-loop control. Simulation results
illustrate the applicability of the design approach for the example of
finite-time transitions between set-points for a tubular bioreactor.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 213-230
Issue: 3
Volume: 14
Year: 2007
Month: 9
X-DOI: 10.1080/13873950701844873
File-URL: http://hdl.handle.net/10.1080/13873950701844873
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:3:p:213-230
Template-Type: ReDIF-Article 1.0
Author-Name: T. Kreuzinger
Author-X-Name-First: T.
Author-X-Name-Last: Kreuzinger
Author-Name: M. Bitzer
Author-X-Name-First: M.
Author-X-Name-Last: Bitzer
Author-Name: W. Marquardt
Author-X-Name-First: W.
Author-X-Name-Last: Marquardt
Title: Mathematical modelling of a domestic heating system with stratified storage tank
Abstract:
A hybrid distributed parameter model of a heating system for
domestic hot water is presented in this paper. This heating system
comprises a condensing boiler (burner), a counter current heat exchanger,
and a so-called stratified storage tank which is the state of the art
domestic hot water storage unit. The paper presents the model for the
different operational modes of the plant which are described by a finite
state automaton representing the discrete-event dynamics and driving the
underlying continuous-time dynamics of the storage tank, the heat
exchanger, and the burner. These interconnected components are modelled by
a system of six coupled, quasi-linear partial differential equations
(PDEs) comprising diffusion-, convection-, and source terms. In order to
perform numerical simulations, the set of PDEs is spatially discretized
using the method of lines. Thereby, the influence of various
discretization schemes on the temporal evolution of the traveling
temperature profiles in the single components is investigated. A high
resolution slope limiter scheme for the stratified storage tank and a
higher order up--/downwind scheme for the heat exchanger and the burner
are found to be an appropriate choice for the spatial discretization of
the model equations in order to adequately cover the plant dynamics.
Simulation results fortify the effectiveness of the chosen discretization
schemes and show the excellent performance of the suggested model
representing the measurement data.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 231-248
Issue: 3
Volume: 14
Year: 2007
Month: 8
X-DOI: 10.1080/13873950701844907
File-URL: http://hdl.handle.net/10.1080/13873950701844907
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:3:p:231-248
Template-Type: ReDIF-Article 1.0
Author-Name: Thomas Kiefer
Author-X-Name-First: Thomas
Author-X-Name-Last: Kiefer
Author-Name: Andreas Kugi
Author-X-Name-First: Andreas
Author-X-Name-Last: Kugi
Title: An analytical approach for modelling asymmetrical hot rolling of heavy plates
Abstract:
During the hot rolling process of heavy plates, asymmetries
in the roll gap due to different circumferential velocities, different
work roll radii or vertical temperature gradients lead to a bending of the
outgoing material. This so-called ski-effect brings along a degradation of
the plate quality with respect to the flatness properties and may lead to
problems in the further processing steps. Thus, it is aimed at designing a
strategy to minimize the ski or even better to avoid the occurrence of the
ski-effect. This work is devoted to the development of a mathematical
model that can be used for online execution in process control as a basis
of a ski control concept. Although most models in the literature are based
on numerical methods (e.g. finite elements), we will present a
semi-analytical approach utilizing the upper bound theorem for ideal
rigid-plastic materials. Starting from a detailed model, simplifications
are made to decrease the execution time. The results thus obtained are
compared both with numerical data from finite element simulations and
measurement data taken in a rolling mill by CCD-camera measurements.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 249-267
Issue: 3
Volume: 14
Year: 2007
Month: 8
X-DOI: 10.1080/13873950701844915
File-URL: http://hdl.handle.net/10.1080/13873950701844915
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:3:p:249-267
Template-Type: ReDIF-Article 1.0
Author-Name: James H. VanZwieten
Author-X-Name-First: James H.
Author-X-Name-Last: VanZwieten
Author-Name: Frederick R. Driscoll
Author-X-Name-First: Frederick R.
Author-X-Name-Last: Driscoll
Title: A comprehensive general simulation of small twin screw displacement hull boats with validation
Abstract:
A comprehensive general simulation of small twin screw
displacement hull boats is developed as a tool to estimate ship and
actuator responses in support of developing and tuning of control systems.
The general form of this model allows many small displacement hull vessels
to be rapidly simulated by specifying a set of 17 vessel parameters. The
response of the vessel in the surge, sway and yaw degrees of motion are
estimated from parametric equations and data compiled from literature and,
when not found in literature, inferred from sea trials. Model validation
and tuning of the coefficients not found in literature is accomplished
using manoeuvring and response data obtained in a series of sea trials.
The parametric model proved to be accurate and, when compared with the sea
trial data, model estimates have rms errors over the vessel operational
range of 0.09 m/s and 0.02 m/s for surge velocity when moving in a
straight line in forward and reverse, respectively. For rotating on a
fixed point, the simulation overestimates the rotational velocity by 7.6%
and has an rms error of 0.27°/s. Open loop circle tests show that
with both propellers rotating at 580 rpm, the simulated vessel has a
minimum turning radius of 24.4 m and can complete a circle in
44 s, which is 18% smaller and 8% faster than during sea trials.
Simulated rotation with the engines in opposite gears at similar RPMs of
500 result in a complete revolution in 68 s, 3 s faster than
during sea trials.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 269-301
Issue: 4
Volume: 14
Year: 2008
Month: 3
X-DOI: 10.1080/13873950802164718
File-URL: http://hdl.handle.net/10.1080/13873950802164718
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Handle: RePEc:taf:nmcmxx:v:14:y:2008:i:4:p:269-301
Template-Type: ReDIF-Article 1.0
Author-Name: Dirk Söffker
Author-X-Name-First: Dirk
Author-X-Name-Last: Söffker
Title: Interaction of intelligent and autonomous systems -- part I: qualitative structuring of interaction
Abstract:
In this part I of the study, the development and the
background of a meta-modelling technique to structure complex environments
of systems is illustrated. A special situation-operator-model (SOM)
developed to model the human-machine-interaction (HMI) is understood as a
structuring approach modelling the interaction of intelligent systems in
general. Part I of this study is structured as follows: Section 1 reflects
on the term modelling with respect to the task: how to model interaction
of unknown interaction partners, Section 2 briefly reviews the basics of
the previously published foundations of the work and the SOM. The
developed situation-operator-metamodelling approach is used to illustrate
the connections between control loops and algorithms in Section 3,
including a systematic view of systems' interaction mechanisms. In part II
(part II available in this issue, pp. 319--339) of the contribution, the
practical applications of the introduced approach are shown.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 303-318
Issue: 4
Volume: 14
Year: 2007
Month: 12
X-DOI: 10.1080/13873950801983837
File-URL: http://hdl.handle.net/10.1080/13873950801983837
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:4:p:303-318
Template-Type: ReDIF-Article 1.0
Author-Name: Elmar Ahle
Author-X-Name-First: Elmar
Author-X-Name-Last: Ahle
Author-Name: Dirk Söffker
Author-X-Name-First: Dirk
Author-X-Name-Last: Söffker
Title: Interaction of intelligent and autonomous systems -- part II: realization of cognitive technical systems
Abstract:
In this study, the application of a meta-modelling technique
to structure complex environments is demonstrated with two examples. A
special situation-operator model developed to model the
human-machine-interaction is applied to automated supervision within the
HMI context and to realize flexible and situated interaction of autonomous
systems. A concept to automated monitoring of human operators is
introduced to illustrate the structuring of complex environments as the
first example. In the second example, this modelling technique is applied
to a mobile robot to autonomously build and update a mental model of the
interaction with the environment as an example of a cognitive technical
system.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 319-339
Issue: 4
Volume: 14
Year: 2007
Month: 12
X-DOI: 10.1080/13873950801983852
File-URL: http://hdl.handle.net/10.1080/13873950801983852
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:4:p:319-339
Template-Type: ReDIF-Article 1.0
Author-Name: Carla Martin-Villalba
Author-X-Name-First: Carla
Author-X-Name-Last: Martin-Villalba
Author-Name: Alfonso Urquia
Author-X-Name-First: Alfonso
Author-X-Name-Last: Urquia
Author-Name: Sebastian Dormido
Author-X-Name-First: Sebastian
Author-X-Name-Last: Dormido
Title: An approach to virtual-lab implementation using Modelica
Abstract:
A novel approach to the implementation of interactive
virtual-labs is proposed. The virtual-lab is completely described in
Modelica language and translated using Dymola. To achieve this goal, a
systematic methodology to transform any Modelica model into a formulation
suitable for interactive simulation has been developed. In addition,
VirtualLabBuilder Modelica library has been programmed.
This library contains a set of Modelica models of visual interactive
elements (i.e. containers, animated geometric shapes and interactive
controls) that allows easy creation of the virtual-lab view (i.e. the
model-to-user interface). This approach has two strong points.
Firstly, it allows taking advantage of the Modelica capabilities for
multi-domain modelling and model reuse. In particular, existing Modelica
libraries for modelling of physical systems can be reused to build the
virtual-lab models. Secondly, VirtualLabBuilder library
allows describing the virtual-lab view with Modelica, which facilitates
its development, maintenance and reuse. The proposed approach is discussed
in this manuscript and it is illustrated by means of the following case
study: a virtual-lab describing the thermodynamic behaviour of a solar
house. VirtualLabBuilder
library can be freely downloaded from http://www.euclides.dia.uned
.es/
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 341-360
Issue: 4
Volume: 14
Year: 2007
Month: 10
X-DOI: 10.1080/13873950701846712
File-URL: http://hdl.handle.net/10.1080/13873950701846712
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:4:p:341-360
Template-Type: ReDIF-Article 1.0
Author-Name: L. J. Yebra
Author-X-Name-First: L. J.
Author-X-Name-Last: Yebra
Author-Name: M. Berenguel
Author-X-Name-First: M.
Author-X-Name-Last: Berenguel
Author-Name: S. Dormido
Author-X-Name-First: S.
Author-X-Name-Last: Dormido
Author-Name: E. Zarza
Author-X-Name-First: E.
Author-X-Name-Last: Zarza
Title: Object oriented modelling and simulation of parabolic trough collectors with modelica
Abstract:
The design of advanced control systems to optimize the
overall performance of parabolic trough collectors solar plants with
direct steam generation is today a high-priority line of research. This
study presents the main development guidelines for dynamic models for use
in simulation and control system design for such plants. The models are
based in the ThermoFluid thermo-hydraulic modelling
framework, developed with the Modelica object oriented
modelling language. The study focuses on the DISS experimental solar
plant, located at the Plataforma Solar de Almería-CIEMAT (South-East
Spain). The main plant operating modes are summarized, as well as the
principal components modelled and modelling assumptions. Simulation
results of a representative real experiment are shown, in which the values
predicted by the model are compared with the real measurements and
discussed.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 361-375
Issue: 4
Volume: 14
Year: 2007
Month: 10
X-DOI: 10.1080/13873950701847199
File-URL: http://hdl.handle.net/10.1080/13873950701847199
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:4:p:361-375
Template-Type: ReDIF-Article 1.0
Author-Name: T. Ochiai
Author-X-Name-First: T.
Author-X-Name-Last: Ochiai
Author-Name: J. C. Nacher
Author-X-Name-First: J. C.
Author-X-Name-Last: Nacher
Title: Stochastic analysis of autoregulatory gene expression dynamics
Abstract:
In this work, the autoregulatory genetic module is
investigated by using stochastic theory. We show here that the stochastic
effect of the second order perturbation theory further reduces the
fluctuation size of the gene expression level more than what is expected
in deterministic methods. Furthermore, dynamical aspects of the system
were investigated. In particular, we estimated the time needed to reach
the equilibrium state.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 377-388
Issue: 4
Volume: 14
Year: 2007
Month: 11
X-DOI: 10.1080/13873950801972186
File-URL: http://hdl.handle.net/10.1080/13873950801972186
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:4:p:377-388
Template-Type: ReDIF-Article 1.0
Author-Name: Boris Lohmann
Author-X-Name-First: Boris
Author-X-Name-Last: Lohmann
Author-Name: Peter C. Müller
Author-X-Name-First: Peter C.
Author-X-Name-Last: Müller
Title: Editorial
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 389-390
Issue: 5
Volume: 14
Year: 2008
Month: 10
X-DOI: 10.1080/13873950701844139
File-URL: http://hdl.handle.net/10.1080/13873950701844139
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:14:y:2008:i:5:p:389-390
Template-Type: ReDIF-Article 1.0
Author-Name: Timo Reis
Author-X-Name-First: Timo
Author-X-Name-Last: Reis
Author-Name: Tatjana Stykel
Author-X-Name-First: Tatjana
Author-X-Name-Last: Stykel
Title: Balanced truncation model reduction of second-order systems
Abstract:
In this paper we consider structure-preserving model
reduction of second-order systems using a balanced truncation approach.
Several sets of singular values are introduced for such systems, which
lead to different concepts of balancing and different second-order
balanced truncation methods. A comparison of these methods with other
second-order balanced truncation techniques is presented. We also show
that, in general, none of the existing structure-preserving balanced
truncation methods for second-order systems preserves stability in the
reduced models. Numerical examples are given that demonstrate the
properties of the new methods.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 391-406
Issue: 5
Volume: 14
Year: 2007
Month: 7
X-DOI: 10.1080/13873950701844170
File-URL: http://hdl.handle.net/10.1080/13873950701844170
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:5:p:391-406
Template-Type: ReDIF-Article 1.0
Author-Name: B. Salimbahrami
Author-X-Name-First: B.
Author-X-Name-Last: Salimbahrami
Author-Name: B. Lohmann
Author-X-Name-First: B.
Author-X-Name-Last: Lohmann
Author-Name: A. Bunse-Gerstner
Author-X-Name-First: A.
Author-X-Name-Last: Bunse-Gerstner
Title: Passive reduced order modelling of second-order systems
Abstract:
Two reduction methods for passive second-order systems are
presented, preserving not only the second-order structure but also the
passivity of the original system. The first method is based on applying a
projection directly to the second-order system using a second-order Krylov
subspace. To increase the number of matching parameters, in the second
approach, it is proposed to reduce the equivalent state space model by a
one-sided Krylov method and to extract the second-order matrices by
applying a similarity transformation to the reduced system.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 407-420
Issue: 5
Volume: 14
Year: 2007
Month: 7
X-DOI: 10.1080/13873950701844279
File-URL: http://hdl.handle.net/10.1080/13873950701844279
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:5:p:407-420
Template-Type: ReDIF-Article 1.0
Author-Name: Ortwin Farle
Author-X-Name-First: Ortwin
Author-X-Name-Last: Farle
Author-Name: Volker Hill
Author-X-Name-First: Volker
Author-X-Name-Last: Hill
Author-Name: Pär Ingelström
Author-X-Name-First: Pär
Author-X-Name-Last: Ingelström
Author-Name: Romanus Dyczij-Edlinger
Author-X-Name-First: Romanus
Author-X-Name-Last: Dyczij-Edlinger
Title: Multi-parameter polynomial order reduction of linear finite element models
Abstract:
In this paper we present a numerically stable method for the
model order reduction of finite element (FE) approximations to passive
microwave structures parameterized by polynomials in several variables.
The proposed method is a projection-based approach using Krylov subspaces
and extends the works of Gunupudi etal. (P. Gunupudi, R.
Khazaka and M. Nakhla, Analysis of transmission line circuits
using multidimensional model reduction techniques, IEEE Trans.
Adv. Packaging 25 (2002), pp. 174--180) and Slone etal.
(R.D. Slone, R. Lee and J.-F. Lee, Broadband model order reduction
of polynomial matrix equations using single-point well-conditioned
asymptotic waveform evaluation: derivations and theory, Int. J.
Numer. Meth. Eng. 58 (2003), pp. 2325--2342). First, we present the
multivariate Krylov space of higher order associated with a
parameter-dependent right-hand-side vector and derive a general recursion
for generating its basis. Next, we propose an advanced algorithm to
compute such basis in a numerically stable way. Finally, we apply the
Krylov basis to construct a reduced order model of the moment-matching
type. The resulting single-point method requires one matrix factorization
only. Numerical examples demonstrate the efficiency and reliability of our
approach.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 421-434
Issue: 5
Volume: 14
Year: 2007
Month: 7
X-DOI: 10.1080/13873950701844220
File-URL: http://hdl.handle.net/10.1080/13873950701844220
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:5:p:421-434
Template-Type: ReDIF-Article 1.0
Author-Name: Rudy Eid
Author-X-Name-First: Rudy
Author-X-Name-Last: Eid
Author-Name: Behnam Salimbahrami
Author-X-Name-First: Behnam
Author-X-Name-Last: Salimbahrami
Author-Name: Boris Lohmann
Author-X-Name-First: Boris
Author-X-Name-Last: Lohmann
Title: Krylov-based order reduction using Laguerre series expansion
Abstract:
This paper presents Krylov-based model order reduction based
on the Laguerre description of the system's transfer function. Starting
from the Laguerre-based reduction method for state space systems, two
extensions are proposed for the reduction of systems of second-order
structures. In addition, the connection between the classical moment
matching and the Laguerre-based reduction approaches is investigated and
their equivalence under specific conditions is presented.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 435-449
Issue: 5
Volume: 14
Year: 2007
Month: 7
X-DOI: 10.1080/13873950701844246
File-URL: http://hdl.handle.net/10.1080/13873950701844246
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:5:p:435-449
Template-Type: ReDIF-Article 1.0
Author-Name: A. Hofer
Author-X-Name-First: A.
Author-X-Name-Last: Hofer
Title: Two controller reduction methods based on convex optimization
Abstract:
This article outlines two approaches for the computation of a
suitable low order controller if a linear discrete-time control system
with a high order controller is given. Actually this step is of
significant importance in the case of the so-called
Q-design procedure and especially in l
1-optimal control system design. Since the main
focus during controller reduction is to maintain the performance of the
closed loop system this task is quite different from the general order
reduction problem and thus requires special methods. In this article two
controller reduction methods are presented, which lead to linear programs.
It is intended to augment the Q-design approach by a
suitable controller reduction step and in this way it should become
possible to utilize the full power of Q-design
and to get controllers of reasonable order. The
performance of the proposed methods is demonstrated by an example.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 451-468
Issue: 5
Volume: 14
Year: 2007
Month: 7
X-DOI: 10.1080/13873950801939771
File-URL: http://hdl.handle.net/10.1080/13873950801939771
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Handle: RePEc:taf:nmcmxx:v:14:y:2007:i:5:p:451-468
Template-Type: ReDIF-Article 1.0
Author-Name: Gerta Zimmer
Author-X-Name-First: Gerta
Author-X-Name-Last: Zimmer
Title: Modelling and simulation of steam turbine processes: individual models for individual tasks
Abstract:
Within power plants, several physical, chemical and
mechanical processes are conducted to transfer the energy, stored in
fossil fuel, into electrical energy. This energy conversion is divided
into several stages. Hitherto, the largest conventional power plants
employ steam turbines as prime movers to drive a generator. Hence, a steam
turbine is one module to convert heat energy into mechanical energy. And
thus it is one link in the chain of energy conversions with the aim of
generating electrical energy. Today, steam turbine industry faces numerous
challenges concerning efficiency, commissioning time, start-up times,
operation, availability, safety, cost-effectiveness, etc. Many of these
tasks can be supported by simulating the transient operational behaviour
of the turbine in advance. For example, the commissioning time can be
shortened if the turbine controllers are initialized with well-tuned
pre-set parameters; cost-effectiveness can be increased by setting aside
unnecessary devices and exactly determining material specifications;
safety may be increased by predicting the impacts of failures and thus
taking the necessary precautions. Different tasks require different
details regarding the employed turbine simulation model. Thus, the turbine
controller may be well tuned with less complex simulation models of
turbine, generator and electrical grid, whereas detailed studies of
failures, mainly the transient behaviour which may lead to serious
damages, may require detailed modelling of the turbine-internal
thermodynamic processes. Here, a brief overview of models which simulate
the transient thermodynamic behaviour of a steam turbine is presented.
Three different approaches will be introduced and compared with respect to
different operating situations. Also, special attention is directed
towards the time dependence of critical states, mainly turbine speed and
pressure development in certain areas. The first model is based on a
simple, linear approach and is suitable of giving a quick overview. The
second one incorporates more details and is useful if the operating point
is close to the design point. Finally, the last model incorporates mass
and energy balances as well as the major non-linearities. Hence it depicts
the turbine behaviour over a large range of operating points.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 469-493
Issue: 6
Volume: 14
Year: 2008
Month: 7
X-DOI: 10.1080/13873950802384001
File-URL: http://hdl.handle.net/10.1080/13873950802384001
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Handle: RePEc:taf:nmcmxx:v:14:y:2008:i:6:p:469-493
Template-Type: ReDIF-Article 1.0
Author-Name: Xiukun Wei
Author-X-Name-First: Xiukun
Author-X-Name-Last: Wei
Author-Name: Luigi del Re
Author-X-Name-First: Luigi
Author-X-Name-Last: del Re
Author-Name: Lihua Liu
Author-X-Name-First: Lihua
Author-X-Name-Last: Liu
Title: Air path identification of diesel engines by LPV techniques for gain scheduled control
Abstract:
Modelling is a key element to improve the performance of
engine control systems, but many factors like non-linearity and complexity
complicate the derivation of sufficiently precise physical models. This
motivates an increasing interest in data based models. Linear models can
successfully represent the engine operation in some reduced regions, but
tend to fail when large operating regions must be considered. This
motivates the interest in deriving and using gain scheduling models or
their natural extension, the linear parameter varying (LPV) models. In
this article we propose to model the air path of diesel engines using
input--output LPV models with a physically motivated structure and
parameters estimated from data. These models are shown to combine good
precision with simplicity and allow the systematic design of optimal and
robust control systems, and can be determined in a very short time if
sufficient data are available.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 495-513
Issue: 6
Volume: 14
Year: 2008
Month: 7
X-DOI: 10.1080/13873950802380850
File-URL: http://hdl.handle.net/10.1080/13873950802380850
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Handle: RePEc:taf:nmcmxx:v:14:y:2008:i:6:p:495-513
Template-Type: ReDIF-Article 1.0
Author-Name: John F. Moxnes
Author-X-Name-First: John F.
Author-X-Name-Last: Moxnes
Author-Name: Kjell Hausken
Author-X-Name-First: Kjell
Author-X-Name-Last: Hausken
Title: The dynamics of athletic performance, fitness and fatigue
Abstract:
We provide a mathematical dynamic model of athletic
performance, fitness and fatigue based on the two well-known principles
‘train to failure’ and ‘use it or lose it’.
The anabolic and catabolic processes are modelled with differential
equations. Fitness is defined as muscle fitness. We model the work power
of any muscle or set of muscles, and the muscle's maximum work power.
Parameters are estimated and we present analytical and numerical results.
The relationships between performance, fitness and fatigue are
demonstrated for various activity scenarios. For example, the model
quantifies the exact manner in which the optimal rest period can be
determined to maximize the performance on a given day. The model provides
realistic predictions, and constitutes a powerful tool which describes the
processes by which performance, fitness and fatigue can be regulated and
controlled.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 515-533
Issue: 6
Volume: 14
Year: 2008
Month: 5
X-DOI: 10.1080/13873950802246473
File-URL: http://hdl.handle.net/10.1080/13873950802246473
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Handle: RePEc:taf:nmcmxx:v:14:y:2008:i:6:p:515-533
Template-Type: ReDIF-Article 1.0
Author-Name: John F. Moxnes
Author-X-Name-First: John F.
Author-X-Name-Last: Moxnes
Author-Name: Kjell Hausken
Author-X-Name-First: Kjell
Author-X-Name-Last: Hausken
Title: Cross-country skiing motion equations, locomotive forces and mass scaling laws
Abstract:
This article presents differential equations for locomotive
force and velocity during cross-country skiing. A muscle's work power is
modelled. Thereafter, a locomotive force that depends on the skier's
velocity is constructed. The external forces aerodynamic drag, friction
forces and the force of gravity are incorporated in order to provide the
equation of motion. Some allometric mass scaling relations are established
and used to analyse the effect of a skier's mass on velocity. The model is
tested by using a GPS instrument. We compare analytically and
experimentally determined skiing distances and velocities as functions of
time, and under different conditions. The article provides tools useful
for practising athletes and coaches.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 535-569
Issue: 6
Volume: 14
Year: 2008
Month: 4
X-DOI: 10.1080/13873950802164643
File-URL: http://hdl.handle.net/10.1080/13873950802164643
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Handle: RePEc:taf:nmcmxx:v:14:y:2008:i:6:p:535-569
Template-Type: ReDIF-Article 1.0
Author-Name: Hung-Ju Chen
Author-X-Name-First: Hung-Ju
Author-X-Name-Last: Chen
Author-Name: Ming-Chia Li
Author-X-Name-First: Ming-Chia
Author-X-Name-Last: Li
Title: Human capital externality and chaotic equilibrium dynamics
Abstract:
This study develops a two-period overlapping generations
model in which adults undertake educational investment decisions on behalf
of young agents. In addition to educational investment, we argue that the
accumulation of human capital is also dependent upon the externality from
average human capital within the economy. In a departure from the previous
literature in this area, we assume that there is a reduction in the
overall productivity of human capital accumulation brought about by human
capital externality, and show that complicated dynamics will emerge under
this circumstance. In addition to displaying the chaotic dynamics in the
sense of Li and Yorke, we also verify the existence of Devaney's chaos and
Smale's chaos.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 571-586
Issue: 6
Volume: 14
Year: 2008
Month: 6
X-DOI: 10.1080/13873950802308901
File-URL: http://hdl.handle.net/10.1080/13873950802308901
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Handle: RePEc:taf:nmcmxx:v:14:y:2008:i:6:p:571-586
Template-Type: ReDIF-Article 1.0
Author-Name: Nadja Hvala
Author-X-Name-First: Nadja
Author-X-Name-Last: Hvala
Author-Name: Mario Zec1
Author-X-Name-First: Mario
Author-X-Name-Last: Zec1
Author-Name: Stanko Strmčnik
Author-X-Name-First: Stanko
Author-X-Name-Last: Strmčnik
Title: Non-linear model parameter estimation--estimating a feasible parameter set with respect to model use
Abstract:
This article deals with non-linear model parameter estimation
from experimental data. As for non-linear models a rigorous
identifiability analysis is difficult to perform, parameter estimation is
performed in such a way that uncertainty in the estimated parameter values
is represented by the range of model use results when the model is used
for a certain purpose. Using this approach, the article presents a
simulation study where the objective is to discover whether the estimation
of model parameters can be improved, so that a small enough range of model
use results is obtained. The results of the study indicate that from plant
measurements available for the estimation of model parameters, it is
possible to extract data that are important for the estimation of model
parameters relative to a certain model use. If these data are improved by
a proper measurement campaign (e.g. proper choice of measured variables,
better accuracy, higher measurement frequency) it is to be expected that a
valid model for a certain model use will be obtained. The simulation study
is performed for an activated sludge model from wastewater treatment,
while the estimation of model parameters is done by Monte Carlo
simulation.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 587-605
Issue: 6
Volume: 14
Year: 2008
Month: 5
X-DOI: 10.1080/13873950802246580
File-URL: http://hdl.handle.net/10.1080/13873950802246580
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Handle: RePEc:taf:nmcmxx:v:14:y:2008:i:6:p:587-605
Template-Type: ReDIF-Article 1.0
Author-Name: R. M. Javier
Author-X-Name-First: R. M.
Author-X-Name-Last: Javier
Author-Name: J. J. DiStefano
Author-X-Name-First: J. J.
Author-X-Name-Last: DiStefano
Title: Dynamical biocontrol systems: insights through mechanistic modelling
Abstract:
Dynamical biological systems can be modelled mathematically
at many levels, from relatively macroscopic, i.e. aggregating many
processes or components into subsystem blocks and associated equations
characterizing overall behaviour, to microscopic, i.e. focusing on
physical mechanisms at the level of individual molecules and associated
unit-process equations reflecting such couplings. Here we examine some
representative examples within this spectrum of approaches, illustrating
the ways in which various investigators handle data-driven modelling
problems associated with drug effects--from mostly blood-borne data;
switch-like responses in cell signalling subsystems--from molecular
biochemistry data; gene network regulation--from pharmacogenomics data;
and tumour-suppressor protein regulation mechanisms--also from molecular
biochemistry data. Special attention is given to the latter, as modelling
of the potential mechanisms involved in this system is an ongoing
investigation in our lab. The biosystem model representations described
here demonstrate to varying degrees the power of more microscopic methods
for discriminating between alternative mechanistic hypotheses of
biocontrol system connectivity and dynamics.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 1-16
Issue: 1
Volume: 15
Year: 2008
Month: 7
X-DOI: 10.1080/13873950802379340
File-URL: http://hdl.handle.net/10.1080/13873950802379340
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Handle: RePEc:taf:nmcmxx:v:15:y:2008:i:1:p:1-16
Template-Type: ReDIF-Article 1.0
Author-Name: Tayfun Çimen
Author-X-Name-First: Tayfun
Author-X-Name-Last: Çimen
Title: Development and validation of a mathematical model for control of constrained non-linear oil tanker motion
Abstract:
Manoeuvrability is of great importance for large tankers in
the marine industry. Manoeuvring, involving yaw rates and drift
velocities, which are not small compared with the forward speed, demands a
mathematical model of considerable complexity. A great deal of effort has
been devoted to the construction of non-linear mathematical models
describing the manoeuvrability of large tankers in deep and confined
waters. This study is concerned with the effect of the rudder on the
turning dynamics of a specific model for ESSO's 190,000-deadweight-ton
(dwt) tankers, whose manoeuvrability performance has been investigated in
1972 using full-scale trial results. The turning or heading response of
the tanker depends on the turning moment generated by the rudder, which in
turn depends on the flow of water over the surface of the rudder.
Unfortunately, the classical model used for representing the flow velocity
at the rudder causes the rudder to react too quickly and to a greater
magnitude (increased turning moment) than is physically possible for an
oil tanker of the size considered. As a result, any control system
designed using this “fast” model benefits from the improved
speed of reaction and increased turning moment produced by the rudder.
Consequently, the controller performance derived from simulation results
will be significantly reduced when applied to a real tanker. To compensate
for this increase, a new rudder model has recently been proposed in the
literature. In this study, a comprehensive validation study of this new
model is carried out using the original experimental data presented in
1972. This study provides strong evidence to alert readers interested in
marine applications that the standard model used for decades in the
literature on ship dynamics is not representative of the motions of a real
tanker. The proposed model, on the other hand, is superior over the
classical model and provides an accurate description of the physical
system.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 17-49
Issue: 1
Volume: 15
Year: 2008
Month: 3
X-DOI: 10.1080/13873950802080153
File-URL: http://hdl.handle.net/10.1080/13873950802080153
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Handle: RePEc:taf:nmcmxx:v:15:y:2008:i:1:p:17-49
Template-Type: ReDIF-Article 1.0
Author-Name: P. Koutsovasilis
Author-X-Name-First: P.
Author-X-Name-Last: Koutsovasilis
Author-Name: V. Quarz
Author-X-Name-First: V.
Author-X-Name-Last: Quarz
Author-Name: M. Beitelschmidt
Author-X-Name-First: M.
Author-X-Name-Last: Beitelschmidt
Title: Standard input data for FEM--MBS coupling: importing alternative model reduction methods into SIMPACK
Abstract:
Various research areas in the field of vehicle modelling,
structural mechanics, engine dynamics, microelectromechanical systems
(MEMS), etc. require the utilization of both multibody system formalism
(MBS) and finite element method (FEM) in order to sufficiently capture the
model's dynamics. The FEM--MBS coupling is accomplished by reducing the
dimension of the FE-modelled part and then importing it into an MBS-code
for further simulation. When using commercial FEM (Nastran, ANSYS, etc.)
as well as MBS (SIMPACK) software packages the necessary standard input
data (SID) file is needed for the coupling procedure (FEMBS interface). A
problem arises by the restriction that both commercial FEM and MBS codes
support only two condensation methods (Guyan reduction and component mode
synthesis (CMS)), thus disabling the direct application of any other
reduction approach (e.g. from the field of control theory) that actually
could be better. In this article, the theoretical background of an
implemented FEM--MBS interface (MORPACK) is presented allowing the
application of any kind of reduction method for FE-modelled structures and
furthermore their import (Ritz approximation) into SIMPACK via the SID
file generation. A benchmark problem (UIC60-rail) is used in order to
capture in SIMPACK the discrepancy between the standardized CMS and the
Krylov subspace method (KSM), as one of the alternatives offered by the
interface.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 51-68
Issue: 1
Volume: 15
Year: 2008
Month: 8
X-DOI: 10.1080/13873950802416365
File-URL: http://hdl.handle.net/10.1080/13873950802416365
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Handle: RePEc:taf:nmcmxx:v:15:y:2008:i:1:p:51-68
Template-Type: ReDIF-Article 1.0
Author-Name: Valentín Valero
Author-X-Name-First: Valentín
Author-X-Name-Last: Valero
Author-Name: Hermenegilda Macià
Author-X-Name-First: Hermenegilda
Author-X-Name-Last: Macià
Title: Removing dead transitions in timed-arc Petri nets
Abstract:
Timed-arc Petri nets (TAPNs) are a timed extension of Petri
nets where tokens are assigned an age indicating the time elapsed from its
creation, and PT-arcs (place to transition arcs) are labelled with time
intervals that are used to restrict the age of the tokens that can be used
to fire the adjacent transition. This is a rather pathological model, as
reachability is undecidable, whereas some other known properties of Petri
nets, like boundedness, coverability and even termination, are decidable.
This article focuses on the problem of detecting dead transitions, i.e.
transitions that can be removed from the model since they can never become
enabled. We prove that this problem is decidable for TAPNs with natural
times, and we present an algorithm that can be used to find dead
transitions in the particular case of 1-safe TAPNs.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 69-82
Issue: 1
Volume: 15
Year: 2008
Month: 8
X-DOI: 10.1080/13873950802416332
File-URL: http://hdl.handle.net/10.1080/13873950802416332
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:15:y:2008:i:1:p:69-82
Template-Type: ReDIF-Article 1.0
Author-Name: Jianping Zeng
Author-X-Name-First: Jianping
Author-X-Name-Last: Zeng
Author-Name: Shiyong Zhang
Author-X-Name-First: Shiyong
Author-X-Name-Last: Zhang
Author-Name: Chengrong Wu
Author-X-Name-First: Chengrong
Author-X-Name-Last: Wu
Author-Name: Xiangwen Ji
Author-X-Name-First: Xiangwen
Author-X-Name-Last: Ji
Title: Modelling topic propagation over the Internet
Abstract:
Because of the booming of the Internet, content security is
becoming more intractable, because of the emergence of complex contents
and the diversity in human activity on the Internet. The article proposes
a model for the dynamics of topic propagation over the Internet. Topics on
the Internet are considered as clusters of contents on websites, which
describe various kinds of events. The model accounts for the behaviours of
websites, such as anti-infection ability, recovery ability, spreading
ability and effective propagation rate. A new topic diffusion mechanism
incorporating Markov model based on topic activity transition is employed
in the model. By means of simulations, we explore the time-dependent
spreading of topics in directed scale-free networks, in which nodes are
considered as websites and directed links represent the source
dependencies between websites. The simulation results accord with the
actual observation very well.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 83-93
Issue: 1
Volume: 15
Year: 2008
Month: 8
X-DOI: 10.1080/13873950802431992
File-URL: http://hdl.handle.net/10.1080/13873950802431992
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:15:y:2008:i:1:p:83-93
Template-Type: ReDIF-Article 1.0
Author-Name: Krzysztof Chwastek
Author-X-Name-First: Krzysztof
Author-X-Name-Last: Chwastek
Title: Modelling of dynamic hysteresis loops using the Jiles--Atherton approach
Abstract:
The article deals with the modelling of dynamic hysteresis
loops. The modelling is carried out within the framework proposed by D.
Jiles and D. Atherton. The dynamic effect of eddy currents is taken into
account using G. Bertotti's approach. A satisfactory agreement between the
measured and the modelled dynamic hysteresis loops as well as the
corresponding loss densities is obtained.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 95-105
Issue: 1
Volume: 15
Year: 2008
Month: 8
X-DOI: 10.1080/13873950802432016
File-URL: http://hdl.handle.net/10.1080/13873950802432016
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:15:y:2008:i:1:p:95-105
Template-Type: ReDIF-Article 1.0
Author-Name: Edgar Delgado-Eckert
Author-X-Name-First: Edgar
Author-X-Name-Last: Delgado-Eckert
Title: Boolean monomial control systems
Abstract:
In this article, we study a class of non-linear control
systems called Boolean (i.e. over the finite field F
2) monomial control systems (BMCS) defined as mappings
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such that
every component gi is a
monomial function in n state variables and in
m input variables. These represent a particular class of
finite state automata. We successfully apply the theory of Boolean
dynamical systems [Colón-Reyes et al., Ann. Comb 8
(2004), pp. 425--439, Delgado-Eckert (2008), Ph.D thesis, http://med
iatum2.ub.tum.de/doc/645326/document.pdf], in particular, the
graph theoretical notion of ‘loop number’ to investigate
controllability issues for BMCS. We found that BMCS containing only one
control input are completely controllable, whereas BMCS displaying more
than one input variable are harder to control. Additionally, we introduce
the principle of loop number assignment, which is in some sense analogous
to the well known ‘pole placement’ method for state
continuous linear systems. Moreover, we present an algorithm that
synthesizes a suitable state feedback controller in order to specify a
desired cyclic behaviour of the closed loop system.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 107-137
Issue: 2
Volume: 15
Year: 2009
Month: 1
X-DOI: 10.1080/13873950902808594
File-URL: http://hdl.handle.net/10.1080/13873950902808594
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:15:y:2009:i:2:p:107-137
Template-Type: ReDIF-Article 1.0
Author-Name: F. Aller
Author-X-Name-First: F.
Author-X-Name-Last: Aller
Author-Name: D. Kukanja
Author-X-Name-First: D.
Author-X-Name-Last: Kukanja
Author-Name: V. Jovan
Author-X-Name-First: V.
Author-X-Name-Last: Jovan
Author-Name: M. Georgiadis
Author-X-Name-First: M.
Author-X-Name-Last: Georgiadis
Title: Modelling the semi-batch vinyl acetate emulsion polymerization in a real-life industrial reactor
Abstract:
A detailed dynamic model of the polymerization reaction of
vinyl acetate in a real-life industrial reactor is presented. With the
recipe and the operating procedures observed in the factory as inputs, the
model predicts with reasonable accuracy the final conversion, the average
particle diameter, the solid content and the viscosity. The manual and
semi-manual operations, and the decision process followed by the operator,
are also modelled in order to replicate closely the process carried out in
the factory. The model provides further insight into the reaction kinetics
and allows us to make knowledge-based decisions. The model is intended to
be used for the optimization of the policy of adding monomer in order to
reduce the batch time.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 139-161
Issue: 2
Volume: 15
Year: 2008
Month: 11
X-DOI: 10.1080/13873950802666357
File-URL: http://hdl.handle.net/10.1080/13873950802666357
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:15:y:2008:i:2:p:139-161
Template-Type: ReDIF-Article 1.0
Author-Name: R. Griesse
Author-X-Name-First: R.
Author-X-Name-Last: Griesse
Author-Name: A. J. Meir
Author-X-Name-First: A. J.
Author-X-Name-Last: Meir
Title: Modelling of a magnetohydrodynamics free surface problem arising in Czochralski crystal growth
Abstract:
A free surface problem arising in the Czochralski (CZ)
crystal growth process is considered. A mathematical model accounting for
the interaction of the molten material with applied and induced magnetic
fields, temperature-induced convection, rotating boundaries and a free
surface is given. The model described avoids some common simplifying
assumptions and allows for more general geometries, and non-axisymmetric
(fully three-dimensional) and time-dependent flow fields. It accounts for
the induced magnetic field and avoids non-realistic idealized boundary
conditions on the magnetic field. The use and limitations of the model in
optimization of crystal growth are also discussed.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 163-175
Issue: 2
Volume: 15
Year: 2008
Month: 9
X-DOI: 10.1080/13873950802551542
File-URL: http://hdl.handle.net/10.1080/13873950802551542
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:15:y:2008:i:2:p:163-175
Template-Type: ReDIF-Article 1.0
Author-Name: H. Hötzendorfer
Author-X-Name-First: H.
Author-X-Name-Last: Hötzendorfer
Author-Name: W. Estelberger
Author-X-Name-First: W.
Author-X-Name-Last: Estelberger
Author-Name: F. Breitenecker
Author-X-Name-First: F.
Author-X-Name-Last: Breitenecker
Author-Name: S. Wassertheurer
Author-X-Name-First: S.
Author-X-Name-Last: Wassertheurer
Title: Three-dimensional cellular automaton simulation of tumour growth in inhomogeneous oxygen environment
Abstract:
Cellular automaton theory has previously been used to study
cell growth. In this study, we present a three-dimensional cellular
automaton model performing the growth simulation of normal and cancerous
cells. The necessary nutrient supply is provided by an artificial arterial
tree which is generated by constrained constructive optimization. Spatial
oxygen diffusion is approximated again by a cellular automaton model. All
results could be illustrated dynamically by three-dimensional volume
visualization. Because of the chosen modelling approach, an extension of
the model to simulate angiogenic processes is possible.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 177-189
Issue: 2
Volume: 15
Year: 2008
Month: 12
X-DOI: 10.1080/13873950902724155
File-URL: http://hdl.handle.net/10.1080/13873950902724155
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Handle: RePEc:taf:nmcmxx:v:15:y:2008:i:2:p:177-189
Template-Type: ReDIF-Article 1.0
Author-Name: Meisam Amiri
Author-X-Name-First: Meisam
Author-X-Name-Last: Amiri
Author-Name: Vahid Esfahanian
Author-X-Name-First: Vahid
Author-X-Name-Last: Esfahanian
Author-Name: Mohammad Reza Hairi-Yazdi
Author-X-Name-First: Mohammad Reza
Author-X-Name-Last: Hairi-Yazdi
Author-Name: Mohsen Esfahanian
Author-X-Name-First: Mohsen
Author-X-Name-Last: Esfahanian
Author-Name: Amir Mohammad Fazeli
Author-X-Name-First: Amir
Author-X-Name-Last: Mohammad Fazeli
Author-Name: Ali Nabi
Author-X-Name-First: Ali
Author-X-Name-Last: Nabi
Title: Feed-forward modelling and fuzzy logic based control strategy for powertrain efficiency improvement in a parallel hybrid electric vehicle
Abstract:
With the stricter limitations on both fuel consumption and
air pollution, the advantages of a hybrid electric vehicle are becoming
more evident than ever. In the present study, an energy management system
for a hybrid electric vehicle is developed. Because the plant under
consideration is nonlinear, multi-domain, time-varying, has multiple
uncertainties and, in addition, the designed control strategy must be able
to obey the driver's commands and achieve the par-internship for a new
generation of vehicle regulations, the fuzzy logic approach is chosen. A
feed-forward hybrid vehicle simulation model is used to demonstrate the
validity and the convenience of the current approach and its results have
been compared with the other parallel hybrid electric vehicle control
strategies. Simulation results show considerable improvement in the
efficiency of the internal combustion engine and, consequently, fuel
consumption and acceleration performances.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 191-207
Issue: 2
Volume: 15
Year: 2008
Month: 9
X-DOI: 10.1080/13873950802532294
File-URL: http://hdl.handle.net/10.1080/13873950802532294
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Handle: RePEc:taf:nmcmxx:v:15:y:2008:i:2:p:191-207
Template-Type: ReDIF-Article 1.0
Author-Name: D. Wild
Author-X-Name-First: D.
Author-X-Name-Last: Wild
Author-Name: T. Meurer
Author-X-Name-First: T.
Author-X-Name-Last: Meurer
Author-Name: A. Kugi
Author-X-Name-First: A.
Author-X-Name-Last: Kugi
Title: Modelling and experimental model validation for a pusher-type reheating furnace
Abstract:
The slab reheating process turns out to play a key role in
dealing with the steadily increasing demands on the quality of hot rolled
steel plates. Improvements both in the throughput of the furnace as well
as the accurate realization of reheating paths for the slabs require to
incorporate modern model-based control design techniques into the furnace
automation. For this, suitable mathematical models with manageable
dimension and complexity have to be determined for the furnace and slab
dynamics. In this contribution, first principles are applied for the
derivation of a physics-based model of the reheating process in a
so-called pusher-type reheating furnace. Thereby, a discontinuous mode of
furnace operation is considered, which is characterized by a varying
number of slabs with variable geometry being discontinuously moved through
the furnace. This, in particular, results in a hybrid structure of the
mathematical model. The accuracy of the mathematical model is validated by
a comparison with experimental data obtained from a measurement campaign
with a test slab performed at an industrial pusher-type reheating furnace.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 209-232
Issue: 3
Volume: 15
Year: 2009
Month: 3
X-DOI: 10.1080/13873950902927683
File-URL: http://hdl.handle.net/10.1080/13873950902927683
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Handle: RePEc:taf:nmcmxx:v:15:y:2009:i:3:p:209-232
Template-Type: ReDIF-Article 1.0
Author-Name: A. Baaiu
Author-X-Name-First: A.
Author-X-Name-Last: Baaiu
Author-Name: F. Couenne
Author-X-Name-First: F.
Author-X-Name-Last: Couenne
Author-Name: D. Eberard
Author-X-Name-First: D.
Author-X-Name-Last: Eberard
Author-Name: C. Jallut
Author-X-Name-First: C.
Author-X-Name-Last: Jallut
Author-Name: L. Lefevre
Author-X-Name-First: L.
Author-X-Name-Last: Lefevre
Author-Name: Y. Legorrec
Author-X-Name-First: Y.
Author-X-Name-Last: Legorrec
Author-Name: B. Maschke
Author-X-Name-First: B.
Author-X-Name-Last: Maschke
Title: Port-based modelling of mass transport phenomena
Abstract:
The goal of this article is to present an extension of the
port-based modelling approach (bond graphs) which applies to systems
subject to heat and mass transfer. The methodology is based on the first
principle, conservation laws and constitutive closure relations. The
latter are the phenomenological laws relating fluxes and thermodynamic
forces. Then instantaneous power conservation appears naturally as a
geometric interconnection structure called Dirac structure. The
multi-level case (several macroscopic spatial scales) is investigated with
the assumption that the spatial scales are separated and may be considered
as two distinct phases. In this case, it is shown that both the
interconnection coupling within a phase and the multi-level
interconnection coupling are Dirac structures.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 233-254
Issue: 3
Volume: 15
Year: 2009
Month: 1
X-DOI: 10.1080/13873950902808578
File-URL: http://hdl.handle.net/10.1080/13873950902808578
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Handle: RePEc:taf:nmcmxx:v:15:y:2009:i:3:p:233-254
Template-Type: ReDIF-Article 1.0
Author-Name: Singa Wang Chiu
Author-X-Name-First: Singa Wang
Author-X-Name-Last: Chiu
Author-Name: Kuang-Ku Chen
Author-X-Name-First: Kuang-Ku
Author-X-Name-Last: Chen
Author-Name: Jyh-Chau Yang
Author-X-Name-First: Jyh-Chau
Author-X-Name-Last: Yang
Title: Optimal replenishment policy for manufacturing systems with failure in rework, backlogging and random breakdown
Abstract:
This article studies the optimal replenishment policy for an
economic manufacturing quantity (EMQ) model with failure in rework,
backlogging and random breakdown. A recent article [P.A. Hayek and M.K.
Salameh, Prod. Plann. Control 2001;12:584--590]
investigated the optimal lot size problem on an imperfect quality EMQ
model. However, in most real-life manufacturing systems random breakdown
is another inevitable reliability factor. To cope with the stochastic
machine failures, the production planners need to calculate the mean time
between failures and establish a robust plan accordingly, so that the
overall production-inventory costs for such an unreliable system can be
minimized. This study incorporates random machine breakdown and failure in
rework factors into the imperfect EMQ model examined by the aforementioned
paper. Mathematical modelling and cost analysis are employed and the
renewal reward theorem is used to deal with variable cycle length.
Convexity of the long-run average cost function is proved and optimal
replenishment policy for such an imperfect EMQ model is derived. Numerical
example demonstrates its practical usages.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 255-274
Issue: 3
Volume: 15
Year: 2009
Month: 1
X-DOI: 10.1080/13873950902808602
File-URL: http://hdl.handle.net/10.1080/13873950902808602
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Handle: RePEc:taf:nmcmxx:v:15:y:2009:i:3:p:255-274
Template-Type: ReDIF-Article 1.0
Author-Name: S. Sacone
Author-X-Name-First: S.
Author-X-Name-Last: Sacone
Author-Name: S. Siri
Author-X-Name-First: S.
Author-X-Name-Last: Siri
Title: An integrated simulation-optimization framework for the operational planning of seaport container terminals
Abstract:
In this article the operational planning of seaport container
terminals is considered by defining a suitable integrated framework in
which simulation and optimization interact. The proposed tool is a
simulation environment (implemented by using the Arena software)
representing the dynamics of a container terminal. When the system faces
some particular conditions (critical events), an optimization procedure
integrated in the simulation tool is called. This means that the
simulation is paused, an optimization problem is solved and the relative
solution is an input for the simulation environment where some system
parameters are modified (generally, the handling rates of some resources
are changed). For this reason, in the present article we consider two
modelling and planning levels about container terminals. The simulation
framework, based on an appropriate discrete-event model, represents the
dynamic behaviour of the terminal, thus it needs to be quite detailed and
it is used as an operational planning tool. On the other hand, the
optimization approach is devised in order to define some system parameters
such as the resource handling rates; in this sense, it can be considered
as a tool for tactical planning. The optimization procedure is based on an
aggregate representation of the terminal where the dynamics is modelled by
means of discrete-time equations.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 275-293
Issue: 3
Volume: 15
Year: 2009
Month: 1
X-DOI: 10.1080/13873950902808636
File-URL: http://hdl.handle.net/10.1080/13873950902808636
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Handle: RePEc:taf:nmcmxx:v:15:y:2009:i:3:p:275-293
Template-Type: ReDIF-Article 1.0
Author-Name: N. Đ. Zrnić
Author-X-Name-First: N. Đ.
Author-X-Name-Last: Zrnić
Author-Name: K. Hoffmann
Author-X-Name-First: K.
Author-X-Name-Last: Hoffmann
Author-Name: S. M. Bošnjak
Author-X-Name-First: S. M.
Author-X-Name-Last: Bošnjak
Title: Modelling of dynamic interaction between structure and trolley for mega container cranes
Abstract:
This article deals with the analysis of trolley impact on the
dynamic behaviour of the flexible structure of the mega quayside container
crane (QCC) boom, identified as the most relevant structural part. It
develops a modelling method for the dynamic response of the large flexible
structure of the QCC boom under a moving trolley. By using FEM the
original structure of the whole crane structure is reduced to an
equivalent model of the boom. The boom is in this way modelled as a system
with distributed parameters, comprising reduced stiffnesses and lumped
masses from other parts of the upper structure. The article looks at the
moving mass approach to achieve the desired performance of the QCC.
Differential equations of the mathematical model are obtained by using
Lagrange's equations and the assumed mode method. The continuum is
discretized by a finite number of admissible functions. Deterministic
simulation gives the dynamic response of the boom for quay-to-ship
container transfer. Results are obtained for the boom deflection and
bending moment values, as well as for the dynamic amplification factor of
deflection.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 295-311
Issue: 3
Volume: 15
Year: 2009
Month: 3
X-DOI: 10.1080/13873950902927675
File-URL: http://hdl.handle.net/10.1080/13873950902927675
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Handle: RePEc:taf:nmcmxx:v:15:y:2009:i:3:p:295-311
Template-Type: ReDIF-Article 1.0
Author-Name: Samy Mziou
Author-X-Name-First: Samy
Author-X-Name-Last: Mziou
Author-Name: Nico Scheerlinck
Author-X-Name-First: Nico
Author-X-Name-Last: Scheerlinck
Author-Name: Bart M. Nicolaï
Author-X-Name-First: Bart M.
Author-X-Name-Last: Nicolaï
Title: Study and modelling of two apple quality attributes: the soluble solids content and the firmness
Abstract:
Recently, the basic dynamics of fruit characteristics have
been modelled using a stochastic approach. The time evolution of apple
quality attributes was represented by means of a system of differential
equations in which the initial conditions and model parameters are both
random. In this work, a complete study of two apple quality attributes,
the soluble solids content and the firmness, is carried out. For each of
these characteristics, the system of differential equations is linear and
the state variables and the parameters are represented as random variables
with their statistical properties (mean values, variances, covariances,
joint probability density function) known at the initial time. The dynamic
behaviour of these statistical properties is analysed. The variance
propagation algorithm is used to obtain an analytical expression of the
dynamic behaviour of the mean value, the variance, the covariance and the
probability density function. A Monte Carlo method and the Latin hypercube
method were developed to obtain a numerical expression of the dynamic
behaviour of these statistical quantities and particularly to follow the
time evolution of joint probability density function which represents one
but the best mean to characterize random phenomena linked with fruit
quality attributes.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 317-336
Issue: 4
Volume: 15
Year: 2009
Month: 3
X-DOI: 10.1080/13873950902955833
File-URL: http://hdl.handle.net/10.1080/13873950902955833
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Handle: RePEc:taf:nmcmxx:v:15:y:2009:i:4:p:317-336
Template-Type: ReDIF-Article 1.0
Author-Name: Eilif Pedersen
Author-X-Name-First: Eilif
Author-X-Name-Last: Pedersen
Title: Rotordynamics and bond graphs: basic models
Abstract:
Basic rotordynamic models such as for the Jeffcott [H. H.
Jeffcott, Lateral vibration of laded shafts in the neighborhood of
a whirling speed--Thee ffect of want of imbalance, Philos.Mag.
37, 1919, pp. 304--314] and Stodola--Green [A. Stodola, Dampf-und
Gasturbinen, Springer-Verlag, Berlin, 1924, R.Green, Gyroscopic
effects of the critical speeds of flexible rotors, J Appl Mech, 15 (1948),
pp. 369--376] rotors are developed in a bond graph formalism. The
equations of motion for a general rotor with an imbalance are derived from
Lagrange's equations to include most rotordynamic phenomena including
gyroscopic effects. The implementation into the bond graph models using
both multibond and scalar bonds is given and discussed. An example of bond
graph models for the classical Jeffcott rotor is included and the
derivation of the complete state equations from the scalar bond graph is
shown in detail. A more complex bond graph-modelling example using the
Stodola--Green model mounted on a stiff shaft with bearing elasticity and
damping is also included. Simulation results for both the models are
shown. The purpose of a bond graph implementation of such rotordynamics
models is to explore the modular and foundational pieces of the bond graph
in more complex rotordynamic or mechatronic models and visualize the
rotordynamic phenomena from the energy flow and visual perspectives.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 337-352
Issue: 4
Volume: 15
Year: 2009
Month: 5
X-DOI: 10.1080/13873950903063116
File-URL: http://hdl.handle.net/10.1080/13873950903063116
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Handle: RePEc:taf:nmcmxx:v:15:y:2009:i:4:p:337-352
Template-Type: ReDIF-Article 1.0
Author-Name: Cor-Jacques Kat
Author-X-Name-First: Cor-Jacques
Author-X-Name-Last: Kat
Author-Name: Pieter Schalk Els
Author-X-Name-First: Pieter
Author-X-Name-Last: Schalk Els
Title: Interconnected air spring model
Abstract:
This article considers the mathematical modelling of the
spring force of three interconnected rolling diaphragm type air springs
used on a 40-ton tri-axle semi-trailer. The aim of the air spring model is
to obtain a validated mathematical model that can be used in full vehicle
multi-body dynamic simulations. The model considers the flow effects in
the pipes connecting the three air springs as well as the mass transfer
between them. Comparisons with experimental results show that the proposed
mathematical model of the interconnected air springs is indeed able to
accurately predict the pressures and forces of the air springs.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 353-370
Issue: 4
Volume: 15
Year: 2009
Month: 3
X-DOI: 10.1080/13873950902955783
File-URL: http://hdl.handle.net/10.1080/13873950902955783
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:15:y:2009:i:4:p:353-370
Template-Type: ReDIF-Article 1.0
Author-Name: Wenfu Xu
Author-X-Name-First: Wenfu
Author-X-Name-Last: Xu
Author-Name: Bin Liang
Author-X-Name-First: Bin
Author-X-Name-Last: Liang
Author-Name: Cheng Li
Author-X-Name-First: Cheng
Author-X-Name-Last: Li
Author-Name: Yu Liu
Author-X-Name-First: Yu
Author-X-Name-Last: Liu
Author-Name: Xueqian Wang
Author-X-Name-First: Xueqian
Author-X-Name-Last: Wang
Title: A modelling and simulation system of space robot for capturing non-cooperative target
Abstract:
Space robotic systems are expected to play an increasingly
important role in the future. The applications include repairing,
refuelling or the de-orbiting of a satellite, or removal of space debris.
Such objects are generally non-cooperative, i.e. neither any artificial
patterns used for the measurement nor grappling fixtures applied for the
capture are mounted on the targets. In this article, we propose a method
for autonomous rendezvous with and capturing of a non-cooperative object
in space and develop a modelling and simulation system to verify the
corresponding algorithms. The system, realized in VC® (Microsoft
Visual C++) environment, is composed of seven modules: Image
Processing and 3D Reconstruction, the Planning and Control of the Chaser,
the Target Controller, the Dynamic Model, the Geometry Model, the
Binocular Cameras Model and the Stereo Calibration
Module. With the system, the closed-loop simulations, including
image grabbing, image processing, pose measurement, chaser guidance,
navigation and control (GNC) and the system's dynamic motion, were
conducted and the key algorithms validated.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 371-393
Issue: 4
Volume: 15
Year: 2009
Month: 5
X-DOI: 10.1080/13873950903036724
File-URL: http://hdl.handle.net/10.1080/13873950903036724
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Handle: RePEc:taf:nmcmxx:v:15:y:2009:i:4:p:371-393
Template-Type: ReDIF-Article 1.0
Author-Name: Minvydas Ragulskis
Author-X-Name-First: Minvydas
Author-X-Name-Last: Ragulskis
Author-Name: Edita Sakyte
Author-X-Name-First: Edita
Author-X-Name-Last: Sakyte
Title: An explicit equation for the dynamics of a particle conveyed by a propagating wave
Abstract:
An explicit governing equation of motion describing nonlinear
dynamics of a particle conveyed by a propagating surface wave is deduced.
A dynamic equilibrium is constructed at the contact point of the particle
and the surface. The mathematical model of the system is constructed in
such a way that it involves dynamically shifted coordinates around the
contact point. Such an approach yields an explicit nonlinear differential
equation. Coexisting attractors and their basin boundaries can be analysed
in the general case. Special computational techniques are developed for
numerical integration of such differential equations with dynamically
shifted coordinates. Attractor control strategy based on small external
impulses is proposed when stable equilibrium points and a limit cycle
coexist. Such control strategies can dramatically increase the
effectiveness of operation and can be applicable in different areas of
engineering where positioning or conveyance is performed by means of
propagating surface waves.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 395-405
Issue: 4
Volume: 15
Year: 2009
Month: 4
X-DOI: 10.1080/13873950903063108
File-URL: http://hdl.handle.net/10.1080/13873950903063108
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:15:y:2009:i:4:p:395-405
Template-Type: ReDIF-Article 1.0
Author-Name: Bernt Lie
Author-X-Name-First: Bernt
Author-X-Name-Last: Lie
Title: Guest editorial
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 407-407
Issue: 5
Volume: 15
Year: 2009
Month: 11
X-DOI: 10.1080/13873950903375353
File-URL: http://hdl.handle.net/10.1080/13873950903375353
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:15:y:2009:i:5:p:407-407
Template-Type: ReDIF-Article 1.0
Author-Name: A. Blanco
Author-X-Name-First: A.
Author-X-Name-Last: Blanco
Author-Name: E. Dahlquist
Author-X-Name-First: E.
Author-X-Name-Last: Dahlquist
Author-Name: J. Kappen
Author-X-Name-First: J.
Author-X-Name-Last: Kappen
Author-Name: J. Manninen
Author-X-Name-First: J.
Author-X-Name-Last: Manninen
Author-Name: C. Negro
Author-X-Name-First: C.
Author-X-Name-Last: Negro
Author-Name: R. Ritala
Author-X-Name-First: R.
Author-X-Name-Last: Ritala
Title: Use of modelling and simulation in the pulp and paper industry
Abstract:
In pulp and paper the modelling and simulation of the pulp
production processes was the first major application. Since then several
other applications have been realised though papermaking has never been on
the lead concerning the use of computer-based modelling and simulation.
The complex nature of the materials is one of the most demanding
challenges and the biggest hurdle for any electronic description of the
papermaking process or paper itself. So other industries took the lead and
it is now for the paper industry to learn from these industries what can
be done with the help of computers to control or optimise processes or to
design new grades. The application of results gained with the
use of modelling and simulation techniques in pulp and paper manufacturing
processes has helped the industry to, for example, reduce emissions and
increase the productivity and cost-efficiency of the processes. Still
there are many important tasks open. A better understanding of the
mechanisms of the processes and their control loops has to be achieved in
order to further improve the paper quality, stabilise the wet-end
chemistry, and enhance the runnability. Important features to be developed
are new process designs, efficient process monitoring and systems that
offer decision support during operation. In this paper a
review of the state of the art on modelling and simulation in the pulp and
paper industry is presented as well as further research needs.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 409-423
Issue: 5
Volume: 15
Year: 2009
Month: 9
X-DOI: 10.1080/13873950903375387
File-URL: http://hdl.handle.net/10.1080/13873950903375387
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Handle: RePEc:taf:nmcmxx:v:15:y:2009:i:5:p:409-423
Template-Type: ReDIF-Article 1.0
Author-Name: A. Avelin
Author-X-Name-First: A.
Author-X-Name-Last: Avelin
Author-Name: J. Jansson
Author-X-Name-First: J.
Author-X-Name-Last: Jansson
Author-Name: E. Dotzauer
Author-X-Name-First: E.
Author-X-Name-Last: Dotzauer
Author-Name: E. Dahlquist
Author-X-Name-First: E.
Author-X-Name-Last: Dahlquist
Title: Use of combined physical and statistical models for online applications in the pulp and paper industry
Abstract:
This paper discusses the accuracy of different types of
models. Statistical models are based on process data and/or observations
from lab measurements. This class of models are called black box models.
Physical models use physical relationships to describe a process. These
are called white box models or first principle models. The third group is
sometimes called grey box models, being a combination of black box and
white box models. Here we discuss two examples of model types. One is a
statistical model where an artificial neural network is used to predict
NO x in the
exhaust gases from a boiler at Mälarenergi AB in Västerås,
Sweden. The second example is a grey box model of a continuous digester.
The digester model includes mass balances, energy balances, chemical
reactions and physical geometrical constraints to simulate the real
digester. We also propose that a more sophisticated model is not required
to increase the accuracy of the predicted measurements.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 425-434
Issue: 5
Volume: 15
Year: 2009
Month: 9
X-DOI: 10.1080/13873950903375403
File-URL: http://hdl.handle.net/10.1080/13873950903375403
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:15:y:2009:i:5:p:425-434
Template-Type: ReDIF-Article 1.0
Author-Name: Heikki Jokinen
Author-X-Name-First: Heikki
Author-X-Name-Last: Jokinen
Author-Name: Kimmo Konkarikoski
Author-X-Name-First: Kimmo
Author-X-Name-Last: Konkarikoski
Author-Name: Petteri Pulkkinen
Author-X-Name-First: Petteri
Author-X-Name-Last: Pulkkinen
Author-Name: Risto Ritala
Author-X-Name-First: Risto
Author-X-Name-Last: Ritala
Title: Operations’ decision making under uncertainty: case studies on papermaking
Abstract:
Operational decisions are influenced not only by the data and
models available to the decision maker but also by the uncertainty in the
data and in model-based predictions about the impacts of decision makers'
actions. In non-linear systems the potential actions may have widely
differing uncertainty associated with them. Then the decision maker must
take an attitude towards risk and balance that against the expectation
value of performance. In stochastic optimization, methods to deal with
uncertainty have been developed. However, these methods have not been
widely used in decision making about operating industrial processes. In
this article, we first present a short summary of decision making under
uncertainty and then suggest that the mathematical structure of stochastic
optimization serves as a model for the architecture of future operational
decision support systems. We demonstrate this framework by analysing four
idealized operational decision cases, which are closely related to
practical daily decision making tasks at paper mills. However, the
explicit risk analysis introduces concepts that are new to operational
decision makers -- operators and engineers -- and thus is challenging to
implement in practice.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 435-452
Issue: 5
Volume: 15
Year: 2009
Month: 9
X-DOI: 10.1080/13873950903375429
File-URL: http://hdl.handle.net/10.1080/13873950903375429
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Handle: RePEc:taf:nmcmxx:v:15:y:2009:i:5:p:435-452
Template-Type: ReDIF-Article 1.0
Author-Name: A. Alonso
Author-X-Name-First: A.
Author-X-Name-Last: Alonso
Author-Name: C. Negro
Author-X-Name-First: C.
Author-X-Name-Last: Negro
Author-Name: A. Blanco
Author-X-Name-First: A.
Author-X-Name-Last: Blanco
Author-Name: I. San Pío
Author-X-Name-First: I.
Author-X-Name-Last: San Pío
Title: Application of advanced data treatment to predict paper properties
Abstract:
Papermaking is an industrial process that is becoming more
competitive nowadays. In this process there are numerous techniques and
measurements to indicate paper quality. To increase competitiveness a good
control of paper quality is needed through paper properties predictions
from different process measurements. However, complex physico-chemical
processes take place during papermaking, and thus, paper property
predictions are not easy to obtain, especially in the wet-end area. In the
wet end flocculation takes place, which will determine the floc properties
during the formation of the sheet, and therefore, it will influence
retention, drainage and formation. These strongly affect the runnability
of the machine and the properties of the final product, and thus, using
wet-end measurements for the predictions implies advanced data treatment.
Artificial neural networks have been used in this article to predict
newsprint paper properties from wet-end parameters. Results show that
formation and strength properties can be robustly predicted from pulp
properties at the headbox, flocculation parameters and machine speed.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 453-462
Issue: 5
Volume: 15
Year: 2009
Month: 9
X-DOI: 10.1080/13873950903375445
File-URL: http://hdl.handle.net/10.1080/13873950903375445
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Handle: RePEc:taf:nmcmxx:v:15:y:2009:i:5:p:453-462
Template-Type: ReDIF-Article 1.0
Author-Name: Bernt Lie
Author-X-Name-First: Bernt
Author-X-Name-Last: Lie
Title: Model uncertainty and control consequences: a paper machine study
Abstract:
Deterministic and statistical descriptions of parametric
model uncertainties are discussed and illustrated with a case study from
the paper industry. Prediction uncertainties under open loop and closed
loop operation are then studied. The results illustrate the importance of
a realistic description of parametric uncertainties, and also how closed
loop operation can reduce the prediction sensitivity due to parameter
uncertainties.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 463-477
Issue: 5
Volume: 15
Year: 2009
Month: 9
X-DOI: 10.1080/13873950903375452
File-URL: http://hdl.handle.net/10.1080/13873950903375452
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Handle: RePEc:taf:nmcmxx:v:15:y:2009:i:5:p:463-477
Template-Type: ReDIF-Article 1.0
Author-Name: Aleš Belič
Author-X-Name-First: Aleš
Author-X-Name-Last: Belič
Title: Modelling in systems biology, neurology and pharmacy
Abstract:
In the last decade, some significant changes occurred in the
bio-medical area with the introduction of systemic view. In neurology and
pharmacokinetics, the systemic paradigm was already well accepted, whereas
other areas of bio-medicine were more or less accepting the reductionism
paradigm where systems were studied through the analysis of its isolated
sub-systems. The genome project showed that it is not possible to explain
the diversity of life only with combinations of genes, which resulted in a
new science called systems biology. Mathematical modelling, as one of the
principal tools of control engineering, is now becoming a necessary tool
in the analysis of biological systems. Interdisciplinary research has the
already showed significant advantages over single-disciplinary research;
however, the communication barrier between scientists of different
backgrounds is still a major problem. Therefore, mathematical modelling is
not as widely used in life sciences as would be expected with the
potential benefits to the area.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 479-491
Issue: 6
Volume: 15
Year: 2009
Month: 9
X-DOI: 10.1080/13873950903375304
File-URL: http://hdl.handle.net/10.1080/13873950903375304
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Handle: RePEc:taf:nmcmxx:v:15:y:2009:i:6:p:479-491
Template-Type: ReDIF-Article 1.0
Author-Name: Türker Nazmi Erbil
Author-X-Name-First: Türker Nazmi
Author-X-Name-Last: Erbil
Author-Name: Coşku Kasnakoğlu
Author-X-Name-First: Coşku
Author-X-Name-Last: Kasnakoğlu
Title: Feedback flow control employing local dynamical modelling with wavelets
Abstract:
In this paper, we utilize wavelet transform to obtain
dynamical models describing the behaviour of fluid flow in a local spatial
region of interest. First, snapshots of the flow are obtained from
experiments or from computational fluid dynamics (CFD) simulations of the
governing equations. A wavelet family and decomposition level is selected
by assessing the reconstruction success under the resulting inverse
transform. The flow is then expanded onto a set of basis vectors that are
constructed from the wavelet function. The wavelet coefficients associated
with the basis vectors capture the time variation of the flow within the
spatial region covered by the support of the basis vectors. A dynamical
model is established for these coefficients by using subspace
identification methods. The approach developed is applied to a sample flow
configuration on a square domain where the input affects the system
through the boundary conditions. It is observed that there is good
agreement between CFD simulation results and the predictions of the
dynamical model. A controller is designed based on the dynamical model and
is seen to be successful in regulating the velocity of a given point
within the region of interest.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 493-513
Issue: 6
Volume: 15
Year: 2009
Month: 6
X-DOI: 10.1080/13873950903187253
File-URL: http://hdl.handle.net/10.1080/13873950903187253
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Handle: RePEc:taf:nmcmxx:v:15:y:2009:i:6:p:493-513
Template-Type: ReDIF-Article 1.0
Author-Name: Bernd Möller
Author-X-Name-First: Bernd
Author-X-Name-Last: Möller
Author-Name: Wolfgang Graf
Author-X-Name-First: Wolfgang
Author-X-Name-Last: Graf
Author-Name: Jan-Uwe Sickert
Author-X-Name-First: Jan-Uwe
Author-X-Name-Last: Sickert
Author-Name: Frank Steinigen
Author-X-Name-First: Frank
Author-X-Name-Last: Steinigen
Title: Fuzzy random processes and their application to dynamic analysis of structures
Abstract:
In many engineering problems the dynamical reactions of
structures depend on uncertain data. For considering this uncertainty,
fuzzy random processes are applied. An enhanced dynamic analysis method
called fuzzy stochastic finite element method (FSFEM) has been developed
in order to consider the fuzzy random processes within the dynamic
analysis of structures. A suitable discretization strategy enables the
repeated processing of FE algorithms as deterministic fundamental
solution. In this paper the FE multi-reference-plane model is extended to
fuzzy randomness and dynamic loads. The numerical solution is based on the
fuzzy stochastic sampling (FSS). FSS and FSFEM are applied for the
numerical simulation of the load-bearing capacity of a strengthened RC
plate under static and dynamic loads.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 515-534
Issue: 6
Volume: 15
Year: 2009
Month: 9
X-DOI: 10.1080/13873950903375338
File-URL: http://hdl.handle.net/10.1080/13873950903375338
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Handle: RePEc:taf:nmcmxx:v:15:y:2009:i:6:p:515-534
Template-Type: ReDIF-Article 1.0
Author-Name: Latifeh PourMohammadBagher
Author-X-Name-First: Latifeh
Author-X-Name-Last: PourMohammadBagher
Author-Name: Marjan Kaedi
Author-X-Name-First: Marjan
Author-X-Name-Last: Kaedi
Author-Name: Nasser Ghasem-Aghaee
Author-X-Name-First: Nasser
Author-X-Name-Last: Ghasem-Aghaee
Author-Name: Tuncer I. Ören
Author-X-Name-First: Tuncer I.
Author-X-Name-Last: Ören
Title: Anger evaluation for fuzzy agents with dynamic personality
Abstract:
Personality and emotions are effective factors in human
decision-making processes. Thus, when an agent has to emulate human
behaviour, not only should this agent think and reason but also should
have emotions and personality. In this article a fuzzy agent with dynamic
personality is modelled based on a five-factor personality model and
implemented in a Java environment. Then it is extended with a fuzzy
emotion component. This emotion component uses calculated personality
factors and some related parameters and then determines the degree of
anger. The proposed personality and emotion model provides a proper
framework for human-like agent decision-making tasks.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 535-553
Issue: 6
Volume: 15
Year: 2009
Month: 6
X-DOI: 10.1080/13873950903139585
File-URL: http://hdl.handle.net/10.1080/13873950903139585
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Handle: RePEc:taf:nmcmxx:v:15:y:2009:i:6:p:535-553
Template-Type: ReDIF-Article 1.0
Author-Name: Ansgar Jüngel
Author-X-Name-First: Ansgar
Author-X-Name-Last: Jüngel
Title: Energy transport in semiconductor devices
Abstract:
The modelling, analysis and numerical approximation of
energy-transport models for semiconductor devices are reviewed. The
derivation of the partial differential equations from the semiconductor
Boltzmann equation is sketched. Furthermore, the main ideas for the
analytical treatment of the equations, employing thermodynamic principles,
are given. A new result is the proof of the weak sequential stability of
approximate solutions to some time-dependent energy-transport equations
with physical transport coefficients. The discretization of the stationary
model using mixed finite elements is explained, and some numerical results
in two and three space dimensions are presented. Finally, energy-transport
models with lattice heating or quantum corrections are reviewed.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 1-22
Issue: 1
Volume: 16
Year: 2010
Month: 1
X-DOI: 10.1080/13873951003679017
File-URL: http://hdl.handle.net/10.1080/13873951003679017
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:1:p:1-22
Template-Type: ReDIF-Article 1.0
Author-Name: F.-J. Santonja
Author-X-Name-First: F.-J.
Author-X-Name-Last: Santonja
Author-Name: R.-J. Villanueva
Author-X-Name-First: R.-J.
Author-X-Name-Last: Villanueva
Author-Name: L. Jódar
Author-X-Name-First: L.
Author-X-Name-Last: Jódar
Author-Name: G. Gonzalez-Parra
Author-X-Name-First: G.
Author-X-Name-Last: Gonzalez-Parra
Title: Mathematical modelling of social obesity epidemic in the region of Valencia, Spain
Abstract:
In this article, we analyse the incidence of excess weight in
24- to 65-year-old residents in the region of Valencia, Spain, and predict
its behaviour in the coming years. In addition, we present some possible
strategies to prevent the spread of the obesity epidemic. We
use classical logistic regression analysis to find out that a sedentary
lifestyle and unhealthy nutritional habits are the most important causes
of obesity in the 24- to 65-year-old population in Valencia. We propose a
new mathematical model of epidemiological type to predict the incidence of
excess weight in this population in the coming years. Based on the
mathematical model sensitivity analysis, some possible general strategies
to reverse the increasing trend of obesity are suggested. The
obese population in the region of Valencia is increasing (11.6% in 2000
and 13.48% in 2005) and the future is worrisome. Our model predicts that
15.52% of the population in Valencia will be obese by 2011. Model
sensitivity analysis suggests that obesity prevention strategies (healthy
advertising campaigns) are more effective than obesity treatment
strategies (physical activity) involving the obese and overweight
subpopulation in controlling the increase of adulthood obesity in the
region of Valencia.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 23-34
Issue: 1
Volume: 16
Year: 2009
Month: 11
X-DOI: 10.1080/13873951003590149
File-URL: http://hdl.handle.net/10.1080/13873951003590149
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Handle: RePEc:taf:nmcmxx:v:16:y:2009:i:1:p:23-34
Template-Type: ReDIF-Article 1.0
Author-Name: S. Ali A. Moosavian
Author-X-Name-First: S. Ali A.
Author-X-Name-Last: Moosavian
Author-Name: Alireza Pourreza
Author-X-Name-First: Alireza
Author-X-Name-Last: Pourreza
Author-Name: Khalil Alipour
Author-X-Name-First: Khalil
Author-X-Name-Last: Alipour
Title: Dynamics and stability of a hybrid serial-parallel mobile robot
Abstract:
Kinematics, dynamics, and stability analysis of a hybrid
serial-parallel wheeled mobile robot is detailed in this paper.
Privileging the advantages of both serial and parallel robots, the
suggested structure will provide higher stability for heavy object
manipulation by a mobile robotic system. The proposed system is made of a
differentially-driven wheeled platform, a planar parallel manipulator,
which is called here as star-triangle (ST) mechanism, and a serial
Puma-type manipulator arm. In order to develop a comprehensive kinematics
model of the robot; first it is divided into three modules, i.e. a mobile
platform, a parallel ST mechanism, and a serial robot. Next, a closed-form
dynamics model is derived for the whole hybrid system based on a combined
Newton--Euler and Lagrange formulation. Then, a careful validation
procedure is presented to verify the obtained dynamics model. Finally,
using the new postural stability metric named as moment-height stability
(MHS), the important role of the parallel ST mechanism for stabilizing the
mobile robotic system is demonstrated. The obtained results show that the
proposed hybrid serial--parallel arrangement effectively enhances the
tip-over stability of the overall mobile robotic system. Hence, it can be
successfully exploited to prevent tip-over instability particularly during
heavy object manipulation tasks.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 35-56
Issue: 1
Volume: 16
Year: 2010
Month: 2
X-DOI: 10.1080/13873951003676518
File-URL: http://hdl.handle.net/10.1080/13873951003676518
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:1:p:35-56
Template-Type: ReDIF-Article 1.0
Author-Name: P. Koutsovasilis
Author-X-Name-First: P.
Author-X-Name-Last: Koutsovasilis
Author-Name: M. Beitelschmidt
Author-X-Name-First: M.
Author-X-Name-Last: Beitelschmidt
Title: Model order reduction of finite element models: improved component mode synthesis
Abstract:
The finite element (FE) approach constitutes an essential
methodology when modelling the elastic properties of structures in various
research disciplines such as structural mechanics, engine dynamics and so
on. Because of increased accuracy requirements, the FE method results in
discretized models, which are described by higher order ordinary
differential equations, or, in FE terms, by a large number of degrees of
freedom (DoF). In this regard, the application of an additional
methodology, referred to as the model order reduction (MOR) or DoF
condensation, is rather compulsory. Herein, a reduced dimension set of
ordinary differential equations is generated, i.e. the initially large
number of DoF is condensed, while aiming to keep the dynamics of the
original model as intact as possible. In the commercially available FE
software tools, the static and the component mode syntheses (CMS) are the
only available integrated condensation methods. The latter represents the
state of the art generating well-correlated reduced order models (ROMs),
which can be further utilized for FE or multi-body systems simulations.
Taking into consideration the information loss of the CMS, which is
introduced by its part-static nature, the improved CMS (ICMS) method is
proposed. Here the algorithmic scheme of the standard CMS is adopted,
which is qualitatively improved by adequately considering the advantageous
characteristics of another MOR approach, the so-called improved reduction
system method. The ICMS results in better correlated reduced order models
in comparison to all the aforementioned methods, while preserving the
required structural properties of the original FE model.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 57-73
Issue: 1
Volume: 16
Year: 2009
Month: 12
X-DOI: 10.1080/13873951003590214
File-URL: http://hdl.handle.net/10.1080/13873951003590214
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Handle: RePEc:taf:nmcmxx:v:16:y:2009:i:1:p:57-73
Template-Type: ReDIF-Article 1.0
Author-Name: Falk Ebert
Author-X-Name-First: Falk
Author-X-Name-Last: Ebert
Title: A note on POD model reduction methods for DAEs
Abstract:
We review some known results for proper orthogonal
decomposition (POD) model order reduction applied to ordinary differential
equations (ODEs). Then, these results are generalized for several types of
differential-algebraic equations (DAEs). We provide algorithms for the
model reduction and error bounds for the reduced-order models. Some limits
of the approach are pointed out and alternative methods for reduced-order
subspace approximation are presented. The POD approach is tested and
evaluated for a medium-sized DAE example from multi-body dynamics.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 115-131
Issue: 2
Volume: 16
Year: 2010
Month: 2
X-DOI: 10.1080/13873951003740041
File-URL: http://hdl.handle.net/10.1080/13873951003740041
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:2:p:115-131
Template-Type: ReDIF-Article 1.0
Author-Name: Marko Milojković
Author-X-Name-First: Marko
Author-X-Name-Last: Milojković
Author-Name: Saša Nikolić
Author-X-Name-First: Saša
Author-X-Name-Last: Nikolić
Author-Name: Bratislav Danković
Author-X-Name-First: Bratislav
Author-X-Name-Last: Danković
Author-Name: Dragan Antić
Author-X-Name-First: Dragan
Author-X-Name-Last: Antić
Author-Name: Zoran Jovanović
Author-X-Name-First: Zoran
Author-X-Name-Last: Jovanović
Title: Modelling of dynamical systems based on almost orthogonal polynomials
Abstract:
A new class of the almost orthogonal filters is described in
this article. These filters are a generalization of the classical
orthogonal filters commonly used in the circuit theory, control system
theory, signal processing, and process identification. Almost orthogonal
filters generate the series of almost orthogonal Legendre functions over
the interval (0, ∞). It is well known that all real systems suffer
from some imperfections, so the models of these systems should reflect
this fact. A new method for obtaining an imperfect system model is
proposed. This method uses an almost orthogonal filter, which is based on
almost orthogonal functions. Experiments with modular servo drive were
performed to validate theoretical results and demonstrate that the method
described in the article is suitable for modelling of imperfect systems.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 133-144
Issue: 2
Volume: 16
Year: 2010
Month: 2
X-DOI: 10.1080/13873951003740082
File-URL: http://hdl.handle.net/10.1080/13873951003740082
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:2:p:133-144
Template-Type: ReDIF-Article 1.0
Author-Name: N.Đ. Zrnić
Author-X-Name-First: N.Đ.
Author-X-Name-Last: Zrnić
Author-Name: S.M. Bošnjak
Author-X-Name-First: S.M.
Author-X-Name-Last: Bošnjak
Author-Name: K. Hoffmann
Author-X-Name-First: K.
Author-X-Name-Last: Hoffmann
Title: Parameter sensitivity analysis of non-dimensional models of quayside container cranes
Abstract:
This paper gives an analysis of dynamic behaviour of the
waterside boom, previously identified as the most important structural
part of the mega quayside container cranes (QCC) under moving concentrated
mass. The non-dimensional mathematical model used in this paper presents a
conceptual substitution of the real system of the mega container crane
boom and provides understanding and prediction of its dynamic behaviour
under the action of a moving trolley. The paper discusses the procedure
for setting up the nondimensional mathematical model of the crane boom as
a necessary condition for an estimation of structural and trolley drive
parameters, such as the effects of stiffness, mass, spatial position of
structural segments as well as trolley velocity and acceleration, on the
dynamic values of deflection under the moving mass. The results obtained
by the simulation of the trolley motion alongside the QCC boom during
container transfer from quay-to-ship are implemented in the parameter
sensitivity analysis in order to obtain mutual influences of the dynamic
parameters.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 145-160
Issue: 2
Volume: 16
Year: 2010
Month: 1
X-DOI: 10.1080/13873951003676534
File-URL: http://hdl.handle.net/10.1080/13873951003676534
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:2:p:145-160
Template-Type: ReDIF-Article 1.0
Author-Name: Dimitri Jeltsema
Author-X-Name-First: Dimitri
Author-X-Name-Last: Jeltsema
Author-Name: Arjan J. van der Schaft
Author-X-Name-First: Arjan J.
Author-X-Name-Last: van der Schaft
Title: Memristive port-Hamiltonian Systems
Abstract:
The port-Hamiltonian modelling framework is extended to a
class of systems containing memristive elements and phenomena. First, the
concept of memristance is generalised to the same generic level as the
port-Hamiltonian framework. Second, the underlying Dirac structure is
augmented with a memristive port. The inclusion of memristive elements in
the port-Hamiltonian framework turns out to be almost as straightforward
as the inclusion of resistive elements. Although a memristor is a
resistive element, it is also a dynamic element since the associated
Ohmian laws are rather expressed in terms of differential equations. This
means that the state space manifold, as naturally defined by the storage
elements, is augmented by the states associated with the memristive
elements. Hence the order of complexity is, in general, defined by the
number of storage elements plus the number of memristors in the system.
Apart from enlarging our repertoire of modelling building blocks, the
inclusion of memristive elements in the existing port-Hamiltonian
formalism possibly opens up new ideas for controller synthesis and design.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 75-93
Issue: 2
Volume: 16
Year: 2010
Month: 2
X-DOI: 10.1080/13873951003690824
File-URL: http://hdl.handle.net/10.1080/13873951003690824
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:2:p:75-93
Template-Type: ReDIF-Article 1.0
Author-Name: M. Manderla
Author-X-Name-First: M.
Author-X-Name-Last: Manderla
Author-Name: D. Schmitt
Author-X-Name-First: D.
Author-X-Name-Last: Schmitt
Author-Name: U. Konigorski
Author-X-Name-First: U.
Author-X-Name-Last: Konigorski
Title: Modelling, simulation and control of a redundant parallel robotic manipulator based on invariant manifolds
Abstract:
In this article a systematic approach of modelling and
control for a parallel robotic manipulator is presented. Regarding the
framework of structured analysis of dynamical systems the derivation of a
differential-algebraic model of the mechanical system is straightforward.
Using some differential-geometric considerations based on invariant
manifolds and the definition of fictitious additional input and output
variables a suitable state feedback can be constructed which transforms
the differential-algebraic representation into a state-space model for the
robotic manipulator. On this basis a classical two-degree-of-freedom
(2-DOF) control structure has been designed using the well-known
input--output linearization and a linear time-variant Kalman filter-based
output feedback. Finally, the control structure including a friction
compensation is applied to the robotic system in the laboratory which
shows the practical applicability of the proposed procedure.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 95-113
Issue: 2
Volume: 16
Year: 2010
Month: 2
X-DOI: 10.1080/13873951003738250
File-URL: http://hdl.handle.net/10.1080/13873951003738250
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:2:p:95-113
Template-Type: ReDIF-Article 1.0
Author-Name: G. Ferretti
Author-X-Name-First: G.
Author-X-Name-Last: Ferretti
Author-Name: F. Casella
Author-X-Name-First: F.
Author-X-Name-Last: Casella
Title: Special issue on object-oriented modelling and simulation
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 161-164
Issue: 3
Volume: 16
Year: 2010
Month: 10
X-DOI: 10.1080/13873954.2010.524349
File-URL: http://hdl.handle.net/10.1080/13873954.2010.524349
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:3:p:161-164
Template-Type: ReDIF-Article 1.0
Author-Name: Miguel A. Rubio
Author-X-Name-First: Miguel A.
Author-X-Name-Last: Rubio
Author-Name: Alfonso Urquia
Author-X-Name-First: Alfonso
Author-X-Name-Last: Urquia
Author-Name: Sebastian Dormido
Author-X-Name-First: Sebastian
Author-X-Name-Last: Dormido
Title: Dynamic modelling of PEM fuel cells using the FuelCellLib Modelica library
Abstract:
FuelCellLib is a free
Modelica library for 1D dynamic modelling of PEMFC (proton exchange
membrane fuel cells). FuelCellLib models describe the
physical--chemical phenomena that take place in the cell cathode and the
membrane, including the electrochemical reactions in the catalytic layer,
the electron conduction in the catalytic and diffusion layers, the proton
conduction in the proton conductor material (e.g. Nafion polymers) of the
catalytic layer and the membrane, the coexistence of steam and liquid
water, the transport of water in liquid and steam phases, the
electro-osmotic drag, the transport of oxygen in steam phase in the
catalytic and diffusion layers, the cathode flooding, the membrane drying
and the double-layer pseudo-capacitance. The first version of
FuelCellLib was released in 2005. The second version of
the library, released in 2008, is presented in this article. The modelled
phenomena, modelling hypotheses and equations, the library structure and
its validation are discussed. Two different validation studies of
FuelCellLib PEMFC models have been successfully
completed. First, the effect on the simulated cell behaviour of selected
electrochemical parameters and operating conditions has been qualitatively
analysed, being the obtained results in good agreement with the results
reported by other authors. Second, FuelCellLib cell
models have been validated using experimental data. The GAPILib Modelica
library has been used to fit the PEMFC models to experimental data and to
estimate the value of the cell model parameters.
FuelCellLib and GAPILib can be freely downloaded from
http://www.euclides.dia.uned
.es/
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 165-194
Issue: 3
Volume: 16
Year: 2010
Month: 5
X-DOI: 10.1080/13873954.2010.506758
File-URL: http://hdl.handle.net/10.1080/13873954.2010.506758
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:3:p:165-194
Template-Type: ReDIF-Article 1.0
Author-Name: M. Gräber
Author-X-Name-First: M.
Author-X-Name-Last: Gräber
Author-Name: K. Kosowski
Author-X-Name-First: K.
Author-X-Name-Last: Kosowski
Author-Name: C. Richter
Author-X-Name-First: C.
Author-X-Name-Last: Richter
Author-Name: W. Tegethoff
Author-X-Name-First: W.
Author-X-Name-Last: Tegethoff
Title: Modelling of heat pumps with an object-oriented model library for thermodynamic systems
Abstract:
Novel CO2 heat pump systems for domestic hot water
supply are modelled using an object-oriented thermodynamic model library
written in Modelica. Due to the variety of mathematical structures of
thermodynamic models and the possibilities of object-oriented modelling
languages, powerful libraries are often very complex and hard to
understand. The scope of the presented library lies on good readability
and usability for both users and model designers. The basic structure and
design concepts of the library are outlined and also the most important
model concepts are explained. The heat pump system is modelled and
simulation results are compared with test stand measurements. Simulation
results are used to analyse the design of the system and to get
information about possible further improvements.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 195-209
Issue: 3
Volume: 16
Year: 2010
Month: 5
X-DOI: 10.1080/13873954.2010.506799
File-URL: http://hdl.handle.net/10.1080/13873954.2010.506799
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:3:p:195-209
Template-Type: ReDIF-Article 1.0
Author-Name: L.J. Yebra
Author-X-Name-First: L.J.
Author-X-Name-Last: Yebra
Author-Name: M. Berenguel
Author-X-Name-First: M.
Author-X-Name-Last: Berenguel
Author-Name: J. Bonilla
Author-X-Name-First: J.
Author-X-Name-Last: Bonilla
Author-Name: L. Roca
Author-X-Name-First: L.
Author-X-Name-Last: Roca
Author-Name: S. Dormido
Author-X-Name-First: S.
Author-X-Name-Last: Dormido
Author-Name: E. Zarza
Author-X-Name-First: E.
Author-X-Name-Last: Zarza
Title: Object-oriented modelling and simulation of ACUREX solar thermal power plant
Abstract:
Research and development of advanced control systems to
optimize the overall performance of parabolic trough collector (PTC) solar
power plants is a priority line of research at the CIEMAT (Centro de
Investigaciones Energéticas, Medioambientales y Tecnológicas -
Research Centre for Energy, Environment and Technology).
These developments are underway at the CIEMAT's Plataforma Solar de Almera
(PSA), a highly specialized solar energy technology research centre. Some
dynamic models for use in simulation and control of this type of solar
power plant, developed in the PSA ACUREX facility, are presented in this
article. The models developed are based on the ThermoFluid thermohydraulic
modelling framework, in the Modelica modelling language. The ACUREX
facility is presented with the main components modelled and their
respective modelling assumptions. An operation strategy is presented and
modelled based on the StateGraph Modelica library for discrete and
reactive system modelling. A typical experiment is simulated with real
experimental input data, a discrete operating strategy is designed and
predicted model data are presented and discussed.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 211-224
Issue: 3
Volume: 16
Year: 2010
Month: 7
X-DOI: 10.1080/13873954.2010.507420
File-URL: http://hdl.handle.net/10.1080/13873954.2010.507420
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:3:p:211-224
Template-Type: ReDIF-Article 1.0
Author-Name: Alberto Leva
Author-X-Name-First: Alberto
Author-X-Name-Last: Leva
Author-Name: Filippo Donida
Author-X-Name-First: Filippo
Author-X-Name-Last: Donida
Author-Name: Martina Maggio
Author-X-Name-First: Martina
Author-X-Name-Last: Maggio
Title: Object-oriented modelling of starch mashing for simulation-based control studies
Abstract:
In the production of beer, good temperature control of the
starch mashing phase is very important for both the final product quality
and the process efficiency. A precise tuning of the said control is,
however, complicated by the highly non-linear nature of the process, and
often also by the actuation scheme. Based on suitably extended literature
models, this article shows how object-oriented modelling and simulation
(OOMS) can be used to devise a solution to the above problem. A mashing
model is first derived along the OOMS approach, and then the said model is
coupled to a control representation of scalable detail, including a
quasi replica of the control code. Doing
so allows one to easily create and maintain hybrid
overall models that are suitable for system studies on the design and
assessment of both the control strategy and the process instrumentation,
with particular reference to the use of on--off actuation in conjunction
with modulating control.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 225-240
Issue: 3
Volume: 16
Year: 2010
Month: 2
X-DOI: 10.1080/13873954.2010.506749
File-URL: http://hdl.handle.net/10.1080/13873954.2010.506749
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:3:p:225-240
Template-Type: ReDIF-Article 1.0
Author-Name: M.J. Foeken
Author-X-Name-First: M.J.
Author-X-Name-Last: Foeken
Author-Name: M. Voskuijl
Author-X-Name-First: M.
Author-X-Name-Last: Voskuijl
Title: Knowledge-based simulation model generation for control law design applied to a quadrotor UAV
Abstract:
Like for all mechatronic systems, the role of control
software in unmanned aerial vehicle (UAV) design is becoming more
important. As part of an automated control software development framework,
this article discusses the development of a simulation model generation
method. As a basis, the application of knowledge-based engineering (KBE)
is suggested, requiring the definition of an ontology to capture the
various domain concepts and relationships. The initial knowledge base
represents concepts and relations to create models with Modelica, the
object-oriented modelling language used to construct the simulation model.
The need for physics-based, high-fidelity simulation models using the
latest design parameters is illustrated by investigating the model of a
quadrotor UAV. The results show that the obtained model can form the basis
for control design and that the approach provides means to integrate the
dynamics analysis and control design into a modelling framework using a
combination of object-oriented component modelling and KBE principles.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 241-256
Issue: 3
Volume: 16
Year: 2010
Month: 6
X-DOI: 10.1080/13873954.2010.506745
File-URL: http://hdl.handle.net/10.1080/13873954.2010.506745
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:3:p:241-256
Template-Type: ReDIF-Article 1.0
Author-Name: D. Bouskela
Author-X-Name-First: D.
Author-X-Name-Last: Bouskela
Author-Name: V. Chip
Author-X-Name-First: V.
Author-X-Name-Last: Chip
Author-Name: B. El Hefni
Author-X-Name-First: B.
Author-X-Name-Last: El Hefni
Author-Name: J.M. Favennec
Author-X-Name-First: J.M.
Author-X-Name-Last: Favennec
Author-Name: M. Midou
Author-X-Name-First: M.
Author-X-Name-Last: Midou
Author-Name: J. Ninet
Author-X-Name-First: J.
Author-X-Name-Last: Ninet
Title: New method to assess tube support plate clogging phenomena in steam generators of nuclear power plants
Abstract:
Pressurized water reactor steam generators (PWR SGs) are
large components whose main function is to cool the fission reactor by
extracting the thermal power conveyed by the primary coolant, and thus to
produce steam for the turbine generator. Tube support plate (TSP) clogging
phenomena may occur in the SG when iron oxide particles carried in the
secondary feedwater get unavoidably deposited inside the SG structure, and
specifically in two main regions: on the U-tube outer walls and on the
quatrefoil sections of the plates that support the U-tubes. They may
reduce its cooling efficiency and impact its dynamic behaviour, thus
leading to possible safety issues. Methods based on local
inspections of the SG have been designed and are already in use. They
produce estimators of the local TSP clogging ratio, during the yearly
outage of the plant for refuelling and maintenance. A new
method to assess a global estimator of the TSP clogging ratio is
presented. This method is based on a 1D physical model of the SG that
reproduces the complex dynamics of the two-phase flow phenomena inside the
SG. The model was developed in the Modelica language. This
model is used to compute response curves of the SG characteristics to a
particular transient that challenges the dynamics of the SG, when affected
by TSP clogging. The estimator is obtained by comparing the computed
response curves to real response curves measured on-site. The
method is still under validation. However, first results show that it is
able to give global estimators that are consistent with local ones.
This new method is expected to improve the monitoring of possible TSP
clogging phenomena by producing quantitative estimators with better
accuracy, with a quarterly periodicity while the plant is in operation.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 257-267
Issue: 3
Volume: 16
Year: 2010
Month: 6
X-DOI: 10.1080/13873954.2010.506748
File-URL: http://hdl.handle.net/10.1080/13873954.2010.506748
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:3:p:257-267
Template-Type: ReDIF-Article 1.0
Author-Name: F. Donida
Author-X-Name-First: F.
Author-X-Name-Last: Donida
Author-Name: F. Casella
Author-X-Name-First: F.
Author-X-Name-Last: Casella
Author-Name: G. Ferretti
Author-X-Name-First: G.
Author-X-Name-Last: Ferretti
Title: Model order reduction for object-oriented models: a control systems perspective
Abstract:
In recent years several concepts and tools for modelling and
simulation of non-linear heterogeneous and multi-domain systems have been
developed, speeding up to a great extent the process of an accurate
analysis by simulation of increasingly complex technological systems. In
parallel, for dimensioning and, above all, for control system design
purposes, the need of models of reduced complexity has emerged; together
with the need of tools capable of extracting, from the overall dynamic
model, reduced models representing the dominant behaviour. This article
reviews recent results in non-linear model order reduction method (NORM),
originally developed with reference to computer-aided analysis and design
of electronic circuits, and puts them in a control system design-oriented
perspective, pointing out interesting future research directions.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 269-284
Issue: 3
Volume: 16
Year: 2010
Month: 7
X-DOI: 10.1080/13873954.2010.506760
File-URL: http://hdl.handle.net/10.1080/13873954.2010.506760
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:3:p:269-284
Template-Type: ReDIF-Article 1.0
Author-Name: T. Müller
Author-X-Name-First: T.
Author-X-Name-Last: Müller
Author-Name: A. Kugi
Author-X-Name-First: A.
Author-X-Name-Last: Kugi
Author-Name: G. Bachmaier
Author-X-Name-First: G.
Author-X-Name-Last: Bachmaier
Author-Name: M. Gerlich
Author-X-Name-First: M.
Author-X-Name-Last: Gerlich
Title: Modelling and identification of a piezoelectrically driven fuel injection control valve
Abstract:
In this article, the modelling and identification of a
piezoelectrically driven control valve of a common-rail diesel fuel
injector in an experimental setup is presented. The piezoelectric actuator
of the control valve exhibits a strong temperature dependence.
Furthermore, an unknown mechanical parameter in the control valve
mechanics, the idle stroke value, has to be determined. An
optimization-based method is used for temperature adaptation as well as
for the identification of the unknown idle stroke value. Both the
suppression of the temperature dependence and the exact knowledge of the
idle stroke value are essential for the opening width and opening point of
time of the control valve and thus for the accuracy of the fuel injection.
The identification task becomes even more challenging because only the
electrical signals of the actuator, namely voltage and current, are
measurable. The method is successfully validated in an experimental setup.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 285-305
Issue: 4
Volume: 16
Year: 2010
Month: 6
X-DOI: 10.1080/13873954.2010.502027
File-URL: http://hdl.handle.net/10.1080/13873954.2010.502027
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:4:p:285-305
Template-Type: ReDIF-Article 1.0
Author-Name: Stephan Studener
Author-X-Name-First: Stephan
Author-X-Name-Last: Studener
Author-Name: Stephan Roeckenwagner
Author-X-Name-First: Stephan
Author-X-Name-Last: Roeckenwagner
Author-Name: Boris Lohmann
Author-X-Name-First: Boris
Author-X-Name-Last: Lohmann
Title: Spatiotemporal dynamics and feedforward control of an infinite-dimensional, time-variant, thermal-coating process
Abstract:
In this contribution, a model for the spatiotemporal dynamics
of a thermal-coating process is derived from first principles (the
conservation of energy). The model is a dynamical system consisting of a
system of hyperbolic, partial differential equations (PDEs), describing
the evolution of the temperature distribution of the substrate. By
studying the C 0- semigroup
generated by the system operator we find that in discrete time the
infinite-dimensional plant may conveniently be represented by
finite-dimensional operators defined on appropriately chosen Euclidean
spaces. This representation provides the basis for numerical efficient
solution of several optimal feedforward control problems associated with
set point changes and launching of the process. Numerical and experimental
studies highlight the value of this approach.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 307-325
Issue: 4
Volume: 16
Year: 2010
Month: 6
X-DOI: 10.1080/13873954.2010.502662
File-URL: http://hdl.handle.net/10.1080/13873954.2010.502662
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:4:p:307-325
Template-Type: ReDIF-Article 1.0
Author-Name: Tadej Petrič
Author-X-Name-First: Tadej
Author-X-Name-Last: Petrič
Author-Name: Boris Curk
Author-X-Name-First: Boris
Author-X-Name-Last: Curk
Author-Name: Peter Cafuta
Author-X-Name-First: Peter
Author-X-Name-Last: Cafuta
Author-Name: Leon Žlajpah
Author-X-Name-First: Leon
Author-X-Name-Last: Žlajpah
Title: Modelling of the robotic Powerball®: a nonholonomic, underactuated and variable structure-type system
Abstract:
The Powerball® is the commercial name for a gyroscopic
device that is marketed as a wrist exerciser. The device has a rotor with
two underactuated degrees of freedom, which can be actuated by the
appropriate motion of human or robot wrist axes. After the initial spin,
applying the appropriate motion and torques to the housing leads to a
spin-up of the rotor. Finding these torques intuitively is an easy task
for human operators, but a complex task for a technical consideration, for
example, in robotics. This article's main contribution is a
novel dynamic model that considers friction effects. The presented model
includes all three working principles of the device: free rotor mode and
both modes of rotor rolling in the housing. The work introduces models
with one and two degrees of freedom actuation, both of which are suitable
for laboratory control experiments. An estimation of the friction is
discussed, and both the simulation and the experimental results are
presented to evaluate the models.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 327-346
Issue: 4
Volume: 16
Year: 2010
Month: 3
X-DOI: 10.1080/13873954.2010.484237
File-URL: http://hdl.handle.net/10.1080/13873954.2010.484237
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:4:p:327-346
Template-Type: ReDIF-Article 1.0
Author-Name: Klaus J. Diepold
Author-X-Name-First: Klaus J.
Author-X-Name-Last: Diepold
Author-Name: Franz J. Winkler
Author-X-Name-First: Franz J.
Author-X-Name-Last: Winkler
Author-Name: Boris Lohmann
Author-X-Name-First: Boris
Author-X-Name-Last: Lohmann
Title: Systematical hybrid state modelling of complex dynamical systems: The quad-I/HS framework
Abstract:
A three-phase modelling framework for systematically
designing a general class of complex hybrid dynamical systems is proposed.
The framework benefits from a recent decomposition principle, called DSM
(dependency structure matrix), and results in a new
hybrid state model paradigm supporting mathematical analyses. The two
leading methods of complexity handling, modular modelling
and closing under coupling, are therein combined. Each
interaction is modelled as detailed as necessary by aligning the
interaction knowledge to determined weighting coefficients. Proportional,
functional and qualitative (linguistical) knowledge, which is included
through Fuzzy-Logic, is considered. As not much is known
about hybrid systems from the viewpoint of non-linear dynamics, the
framework's potential is shown by modelling an illustration example,
considering attracting regions and a combination of bifurcations and chaos
in different dynamical domains for stability analysis.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 347-371
Issue: 4
Volume: 16
Year: 2010
Month: 6
X-DOI: 10.1080/13873954.2010.505059
File-URL: http://hdl.handle.net/10.1080/13873954.2010.505059
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:4:p:347-371
Template-Type: ReDIF-Article 1.0
Author-Name: Yuan-Shyi Peter Chiu
Author-X-Name-First: Yuan-Shyi Peter
Author-X-Name-Last: Chiu
Author-Name: Chih-An Katherine Lin
Author-X-Name-First: Chih-An Katherine
Author-X-Name-Last: Lin
Author-Name: Huei-Hsin Chang
Author-X-Name-First: Huei-Hsin
Author-X-Name-Last: Chang
Author-Name: Victoria Chiu
Author-X-Name-First: Victoria
Author-X-Name-Last: Chiu
Title: Mathematical modelling for determining economic batch size and optimal number of deliveries for EPQ model with quality assurance
Abstract:
The classic economic production quantity (EPQ) model assumes
a continuous inventory-issuing policy for satisfying product demand and a
perfect production for all items produced. However, in a real-life
vendor--buyer integrated system, a multi-delivery policy is often used in
lieu of continuous issuing policy and it is inevitable to generate
defective items during a production run. This study addresses these issues
by incorporating multiple deliveries of the finished batch, customer's
inventory-holding cost and manufacturer's quality assurance cost into an
EPQ model with the imperfect reworking of random defective items.
Mathematical modelling and analyses are employed. Convexity of the
long-run expected cost function is proved by the use of Hessian matrix
equations, and the closed-form solutions in terms of the optimal lot size
and optimal number of deliveries are obtained. The research results are
demonstrated with a numerical example with a discussion on its practical
usage.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 373-388
Issue: 4
Volume: 16
Year: 2010
Month: 7
X-DOI: 10.1080/13873954.2010.511199
File-URL: http://hdl.handle.net/10.1080/13873954.2010.511199
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:4:p:373-388
Template-Type: ReDIF-Article 1.0
Author-Name: Arnold Baca
Author-X-Name-First: Arnold
Author-X-Name-Last: Baca
Title: Selected examples in biomechanical modelling and simulation
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 389-390
Issue: 5
Volume: 16
Year: 2010
Month: 11
X-DOI: 10.1080/13873954.2010.507073
File-URL: http://hdl.handle.net/10.1080/13873954.2010.507073
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:5:p:389-390
Template-Type: ReDIF-Article 1.0
Author-Name: Karen Roemer
Author-X-Name-First: Karen
Author-X-Name-Last: Roemer
Author-Name: Uwe Jungnickel
Author-X-Name-First: Uwe
Author-X-Name-Last: Jungnickel
Author-Name: Frank Lindner
Author-X-Name-First: Frank
Author-X-Name-Last: Lindner
Author-Name: Thomas L. Milani
Author-X-Name-First: Thomas L.
Author-X-Name-Last: Milani
Title: Multi-body system model of the knee joint and its applications
Abstract:
A basic task in biomechanics is the precise analysis of human
movements and the investigation of muscle forces that are responsible for
these movements. When using inverse dynamics with a focus on the lower
extremities, the knee model type is of major interest, as it is well known
that the calculated muscle forces depend on the knee model type. It is
essential to use individually parameterized models for the knee joint as
well as for the femoropatellar joint while analysing the correlations
between external and internal loads and the efficiency of specific
training exercises for the lower extremities. It will be shown that
different knee model types and femoropatellar model types have a major
influence on calculated muscle forces. Within this study the multi-body
system model was applied to leg extension movements performed on a leg
press machine. Concerning the adjustment of a leg press machine, the
following two questions were considered: How should a leg press machine be
adjusted for individual exercises taking into account the minimization of
knee strain? Does the muscular strain correspond to the load calculated
and applied externally? The results of this application show that the knee
strain could be reduced by 10% after simulative variation of the boundary
conditions given by the leg press machine.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 391-402
Issue: 5
Volume: 16
Year: 2010
Month: 6
X-DOI: 10.1080/13873954.2010.507090
File-URL: http://hdl.handle.net/10.1080/13873954.2010.507090
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:5:p:391-402
Template-Type: ReDIF-Article 1.0
Author-Name: Irene Reichl
Author-X-Name-First: Irene
Author-X-Name-Last: Reichl
Author-Name: Winfried Auzinger
Author-X-Name-First: Winfried
Author-X-Name-Last: Auzinger
Author-Name: Heinz-Bodo Schmiedmayer
Author-X-Name-First: Heinz-Bodo
Author-X-Name-Last: Schmiedmayer
Author-Name: Ewa Weinmüller
Author-X-Name-First: Ewa
Author-X-Name-Last: Weinmüller
Title: Reconstructing the knee joint mechanism from kinematic data
Abstract:
The interpretation of joint kinematics data in terms of
displacements is a product of the type of movement, the measurement
technique and the underlying model of the joint implemented in
optimization procedures. Kinematic constraints reducing the number of
degrees of freedom (DOFs) are expected to compensate for measurement
errors and noise, thus, increasing the reproducibility of joint angles.
One approach already successfully applied by several groups approximates
the healthy human knee joint as a compound hinge joint with minimal
varus/valgus rotation. Most of these optimizations involve an
orthogonality constraint. This contribution compares the effect of a model
with and without orthogonality constraint on the obtained joint rotation
angles. For this purpose, knee joint motion is simulated to generate
kinematic data without noise and with normally distributed noise of
varying size. For small noise the unconstrained model provides more
accurate results, whereas for larger noise this is the case for the
constrained model. This can be attributed to the shape of the objective
function of the unconstrained model near its minimum.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 403-415
Issue: 5
Volume: 16
Year: 2010
Month: 3
X-DOI: 10.1080/13873954.2010.507094
File-URL: http://hdl.handle.net/10.1080/13873954.2010.507094
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:5:p:403-415
Template-Type: ReDIF-Article 1.0
Author-Name: Sigrid Thaller
Author-X-Name-First: Sigrid
Author-X-Name-Last: Thaller
Author-Name: Markus Tilp
Author-X-Name-First: Markus
Author-X-Name-Last: Tilp
Author-Name: Martin Sust
Author-X-Name-First: Martin
Author-X-Name-Last: Sust
Title: The effect of individual neuromuscular properties on performance in sports
Abstract:
We present a mathematical formulation of notions used in
training science such as sports performance, performance determining
factor and performance limiting factor. We give an example of model
equations describing the relationship between individual neuromuscular
properties and the associated performance in sports. An essential factor
in modelling human movements is to determine the values of the subject's
properties individually and in vivo. We perform measurements and identify
the parameters describing the person's properties in the model equation.
Simulations show effects of individual differences in the neuromuscular
properties on the performance. Furthermore, we show the influence of
changes in movement conditions on the performance.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 417-429
Issue: 5
Volume: 16
Year: 2010
Month: 3
X-DOI: 10.1080/13873954.2010.507082
File-URL: http://hdl.handle.net/10.1080/13873954.2010.507082
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:5:p:417-429
Template-Type: ReDIF-Article 1.0
Author-Name: Peter Dabnichki
Author-X-Name-First: Peter
Author-X-Name-Last: Dabnichki
Author-Name: Angel Zhivkov
Author-X-Name-First: Angel
Author-X-Name-Last: Zhivkov
Title: An analytical method for reconstruction of biological objects from discrete noisy data
Abstract:
The work represents a stage in the development of an
integrated process for the analysis of biological objects -- analytical
image reconstruction from noisy data that allows fast dynamical analysis.
The method also provides an interface to discrete methods such as finite
element method (FEM). Two different methods are proposed -- one is based
on theta functions and the other uses analytical ellipsoids. Both methods
possess built-in ability to remove noise from experimental measurements.
The methods also have significant advantages if used in biological
applications as it could process data directly from optical or general
image devices such as cameras, microscopes and scans. Real-time online
reconstruction and relevant computational analysis could be performed due
to the rapid computational speed which in turn provides a good opportunity
for the development of an integrated medical diagnostics technology. Both
methods are demonstrated using appropriate examples.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 431-442
Issue: 5
Volume: 16
Year: 2010
Month: 6
X-DOI: 10.1080/13873954.2010.507101
File-URL: http://hdl.handle.net/10.1080/13873954.2010.507101
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:5:p:431-442
Template-Type: ReDIF-Article 1.0
Author-Name: Falk Hildebrand
Author-X-Name-First: Falk
Author-X-Name-Last: Hildebrand
Author-Name: Axel Schüler
Author-X-Name-First: Axel
Author-X-Name-Last: Schüler
Title: Swimming propulsion and muscle force moments
Abstract:
Based on 3D video analysis of swimming movements hypotheses
on the mechanisms of propulsion are deduced. Body point coordinates and
their first and second derivatives are computed. The limb environment
where water particle displacement occurs is estimated. We apply the
Navier--Stokes equation to compute the total force for those particles.
The shoulder torque is calculated by summation over environments of hand,
forearm and upper arm of infinitesimal torques of displaced water
particles. Similarly, hip torques are computed by summation over
environments of foot, shank and thigh. Our aim is to determine individual
shoulder and hip torques over one movement cycle. These muscle force
moments are related to the velocity of the mass centre as a measure for
propulsion. Simultaneously they serve as controlling data for dry land
strength training. Recommendations for best propulsion techniques are
derived.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 443-453
Issue: 5
Volume: 16
Year: 2010
Month: 6
X-DOI: 10.1080/13873954.2010.507087
File-URL: http://hdl.handle.net/10.1080/13873954.2010.507087
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:5:p:443-453
Template-Type: ReDIF-Article 1.0
Author-Name: Mario Heller
Author-X-Name-First: Mario
Author-X-Name-Last: Heller
Title: Mechanics of doublet firings in motor unit pools
Abstract:
Motor unit double discharges, or doublet
firings, have been described as two consecutive motor unit discharges that
occur with short interspike intervals. By the use of electrical
stimulation protocols, short interspike intervals inserted at the
beginning of a stimulation train have been shown to increase both the peak
force and the rate of rise of force production [S.J. Garland and L.
Griffin, Motor unit double discharges: statistical anomaly or
functional entity? Can. J. Appl. Physiol. 24 (1999), pp.
113--130]. The aim of this article is to estimate possible mechanical
effects of simulated motor unit doublets in selected motor unit pools
(MUPs) during the initial isometric contractions. Five different MUPs with
varying ranges were simulated considering important nonlinearities in the
force response to pairs of stimuli according to Thomas et
al. [C.K. Thomas, R.S. Johansson, and B. Bigland-Ritchie,
Pattern of pulses that maximize force output from single human
thenar motor units. J. Neurophysiol. 82 (1999), pp. 3188--3195].
The results support the hypothesis that double discharges represent a
functional entity: expected increases depend on the properties of the MUP
as a whole. Relative timing of the doublet discharges occurs, but has only
little effect.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 455-464
Issue: 5
Volume: 16
Year: 2010
Month: 3
X-DOI: 10.1080/13873954.2010.507099
File-URL: http://hdl.handle.net/10.1080/13873954.2010.507099
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:5:p:455-464
Template-Type: ReDIF-Article 1.0
Author-Name: Jürgen Perl
Author-X-Name-First: Jürgen
Author-X-Name-Last: Perl
Title: Net-based phase-analysis in motion processes
Abstract:
Back in the 1990s, one of the major problems when analysing
motion processes often was a lack of data. In recent times, the situation
has completely changed. Data are available nearly unlimitedly, and the
problem now is to detect the important information hidden in that huge
amount of automatically recorded data. Data-mining approaches are often
not really helpful as long as it is not clear what to look for or what the
striking features are. During the last 10 years, artificial neural
networks of type Kohonen Feature Map (KFM) became more and more helpful in
the area of motion data analysis by reducing data and classifying them to
useful information [see W. Schöllhorn and J. Perl,
Prozessanalysen in der Bewegungs- und
Sportspielforschung, Spectrum der Sportwissenschaft 14 (1)
(2002), pp. 30--52 and J. Perl, A neural network approach to
movement pattern analysis. Hum. Mov. Sci. 23 (2004), pp.
605--620]. It should be added that for some of the described applications,
in particular in the case of two-level analysis in Section 2.3, the
special KFM-derivate Dynamically Controlled Network (DyCoN) is necessary
[see J. Perl, DyCoN: Ein neuer Ansatz zur
Modellierung und Analyse von Sportspie-Prozessen mit Hilfe neuronaler
Netze, in Sportspiele Erleben, Vermitteln, Trainieren, K. Ferger,
N. Gissel, and J. Schwier, Hrsg., Czwalina, Hamburg, 2002, S. 253--265].
In the following sections, some concepts and current approaches in the
field of net-based data analysis are presented, and a case study
demonstrates how it works in practice.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 465-475
Issue: 5
Volume: 16
Year: 2010
Month: 3
X-DOI: 10.1080/13873954.2010.507097
File-URL: http://hdl.handle.net/10.1080/13873954.2010.507097
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:5:p:465-475
Template-Type: ReDIF-Article 1.0
Author-Name: Kerstin Witte
Author-X-Name-First: Kerstin
Author-X-Name-Last: Witte
Author-Name: Nico Ganter
Author-X-Name-First: Nico
Author-X-Name-Last: Ganter
Author-Name: Christian Baumgart
Author-X-Name-First: Christian
Author-X-Name-Last: Baumgart
Author-Name: Christian Peham
Author-X-Name-First: Christian
Author-X-Name-Last: Peham
Title: Applying a principal component analysis to movement coordination in sport
Abstract:
Because of the complexity of sports movements, biomechanical
analyses contain many kinematical or dynamical parameters and
characteristic curves. Principal component analysis (PCA) is a technique
for simplifying a dataset by reducing multidimensional datasets to lower
dimensions for analysis. The purpose of this article is the presentation
of several studies which used the PCA to solve various problems in the
movement science in sports. In particular, we interpret the number of the
components or also named components with relatively high eigenvalues as
the number of degrees of freedom. For cyclic and automated movements, the
first PCA component is dominant. The PCA was successfully applied to gait
analyses in rehabilitation and in triathlon as well as in riding. Phase
plots could be used to quantify the variability of the movement
coordination.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 477-488
Issue: 5
Volume: 16
Year: 2010
Month: 8
X-DOI: 10.1080/13873954.2010.507079
File-URL: http://hdl.handle.net/10.1080/13873954.2010.507079
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:5:p:477-488
Template-Type: ReDIF-Article 1.0
Author-Name: Clara Prats
Author-X-Name-First: Clara
Author-X-Name-Last: Prats
Author-Name: Jordi Ferrer
Author-X-Name-First: Jordi
Author-X-Name-Last: Ferrer
Author-Name: Anna Gras
Author-X-Name-First: Anna
Author-X-Name-Last: Gras
Author-Name: Marta Ginovart
Author-X-Name-First: Marta
Author-X-Name-Last: Ginovart
Title: Individual-based modelling and simulation of microbial processes: yeast fermentation and multi-species composting
Abstract:
Controlled microbial activity is the core of many industrial
processes. Such dynamic microbial processes must be carefully studied to
optimize their application. They are usually tackled by means of
continuous mathematical modelling at the population level (top-down). An
alternative approach is individual-based modelling (IbM) (bottom-up).
INDISIM is a discrete and spatially explicit IbM. It sets the rules that
govern each microbe and its interaction with its local environment, as
well as the significant environmental processes. Then it performs
simulations that include a large number of microbes, and the behaviour of
the whole system emerges. The rules are changed to reproduce the behaviour
of microbes depending on the system to be studied. Two adaptations of
INDISIM to study yeast fermentations and multi-species composting are
presented in this article (INDISIM-YEAST and INDISIM-COMP), proof of
INDISIM's versatility. A few representative results are also shown.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 489-510
Issue: 6
Volume: 16
Year: 2010
Month: 3
X-DOI: 10.1080/13873954.2010.481809
File-URL: http://hdl.handle.net/10.1080/13873954.2010.481809
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:6:p:489-510
Template-Type: ReDIF-Article 1.0
Author-Name: L.E. Øi
Author-X-Name-First: L.E.
Author-X-Name-Last: Øi
Title: CO2 removal by absorption: challenges in modelling
Abstract:
The traditional method for large-scale CO2 removal
is by absorption in a mixture of an amine and water. The tasks of
modelling this process can be divided into descriptions of absorption and
reaction kinetics, gas/liquid equilibrium, gas and liquid flows and
pressure drop. Process simulation tools containing models for most of
these tasks are commercially available, and the calculated results can be
used as a basis for equipment dimensioning and economical optimization. A
flowsheet calculation in the program Aspen HYSYS® is used as an
example. Calculation convergence is important, especially the column
convergence is critical. For some simplified conditions, calculation of
stage efficiencies can give a satisfactory description of the absorption
process. Computational fluid dynamics is an efficient tool for calculating
flow conditions, pressure drop and temperature profiles, especially for
one-fluid phase. An unsolved problem when using computational fluid
dynamics for gas/liquid processes is the description of the gas/liquid
interfacial area. A major challenge is to combine different models and
calculation tools. An improved model for a specific task must be available
and possible to combine with other calculation tools to be utilized by
other programs. In an example, models for equilibrium and mass transfer
efficiency are used in a flowsheet calculation including CO2
absorption and desorption, followed by economical optimization. The
example illustrates some possibilities, limitations and challenges.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 511-533
Issue: 6
Volume: 16
Year: 2010
Month: 5
X-DOI: 10.1080/13873954.2010.491676
File-URL: http://hdl.handle.net/10.1080/13873954.2010.491676
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:6:p:511-533
Template-Type: ReDIF-Article 1.0
Author-Name: B. Charnomordic
Author-X-Name-First: B.
Author-X-Name-Last: Charnomordic
Author-Name: R. David
Author-X-Name-First: R.
Author-X-Name-Last: David
Author-Name: D. Dochain
Author-X-Name-First: D.
Author-X-Name-Last: Dochain
Author-Name: N. Hilgert
Author-X-Name-First: N.
Author-X-Name-Last: Hilgert
Author-Name: J.-R. Mouret
Author-X-Name-First: J.-R.
Author-X-Name-Last: Mouret
Author-Name: J.-M. Sablayrolles
Author-X-Name-First: J.-M.
Author-X-Name-Last: Sablayrolles
Author-Name: A. Vande Wouwer
Author-X-Name-First: A.
Author-X-Name-Last: Vande Wouwer
Title: Two modelling approaches of winemaking: first principle and metabolic engineering
Abstract:
In this article, two modelling approaches are proposed for
winemaking fermentations. The first one is largely based on the first
principle modelling approach and considers the main yeast physiological
mechanisms. The model accurately predicts the fermentation kinetics of
more than 80% of a large number of experiments performed with 20 wine
yeast strains, 69 musts and different fermentation conditions. Thanks to
the wide domain of validity of the model, a simulator based on this model
coupled to a thermal model was developed to help winemakers to optimize
tank management. It predicts the end of the fermentation and changes in
the rate of fermentation but furthermore includes an optimization module
based on fuzzy logic which allows, via temperature profiles and nitrogen
addition strategies, to decrease the duration of fermentation and the
energy requirements at winery scale according to user specifications. The
objective of the second modelling approach is the development of a
mathematical model of the fermentation process including some minority
by-products known as characteristic flavour compounds. It refers to
metabolic engineering and accounts for the intracellular behaviour of the
yeast Saccharomyces cerevisiae by using approaches like
the metabolic flux analysis (MFA) and the elementary flux modes (EFMs). A
state of the art describes the application of these methods in the
restrained field of winemaking/fermentation conditions and underlines the
potential of such approaches.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 535-553
Issue: 6
Volume: 16
Year: 2010
Month: 8
X-DOI: 10.1080/13873954.2010.514701
File-URL: http://hdl.handle.net/10.1080/13873954.2010.514701
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:6:p:535-553
Template-Type: ReDIF-Article 1.0
Author-Name: Kjell Hausken
Author-X-Name-First: Kjell
Author-X-Name-Last: Hausken
Author-Name: John F. Moxnes
Author-X-Name-First: John F.
Author-X-Name-Last: Moxnes
Title: A closure approximation technique for epidemic models
Abstract:
Stochastic modelling causes an infinite set of ordinary
differential equations for the moments. Closure models are useful as they
recast this infinite set into a finite set of ordinary differential
equations. A general closure principle is developed, which we believe all
closure models should fulfil. In the Liouville model, if all covariances
are zero initially, then they remain at zero for all times. Our closure
principle assumes that this logical implication also should apply for the
closed Liouville model. A specific covariance closure (CC) model is
developed based on the Dirac distribution. It states that all covariances
up to order n-1 differ from zero, whereas all covariances
of order n and higher equal zero. The CC approximation is
compared with Keeling's [Journal of Animal Ecology 69
(2000), pp. 725--736, Journal of Theoretical Biology 205
(2000), pp. 269--281] approximation based on the lognormal distribution
and with the central moment closure approximation based on the
multivariate normal distribution. Closure is applied to the classic
Kermack and McKendrick [Proceedings of the Royal Statistical
Sociecty, Series A 115 (1927), pp. 700--721] equations for
epidemic growth. For the main examples studied the CC approximation of
orders 7--12 outperforms Keeling's approximation.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 555-574
Issue: 6
Volume: 16
Year: 2010
Month: 5
X-DOI: 10.1080/13873954.2010.496149
File-URL: http://hdl.handle.net/10.1080/13873954.2010.496149
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:6:p:555-574
Template-Type: ReDIF-Article 1.0
Author-Name: Daniel Leitner
Author-X-Name-First: Daniel
Author-X-Name-Last: Leitner
Author-Name: Sabine Klepsch
Author-X-Name-First: Sabine
Author-X-Name-Last: Klepsch
Author-Name: Astrid Knieß
Author-X-Name-First: Astrid
Author-X-Name-Last: Knieß
Author-Name: Andrea Schnepf
Author-X-Name-First: Andrea
Author-X-Name-Last: Schnepf
Title: The algorithmic beauty of plant roots -- an L-System model for dynamic root growth simulation
Abstract:
Understanding the impact of root architecture on plant
resource efficiency is important, in particular, in the light of upcoming
shortages of mineral fertilizers and changed environmental conditions. In
the 1950s, a great number of root systems of European cultivated plants
were excavated and studied by L. Kutschera (1960). Her work gave enormous
insight into the variety of root system architectures and helped to
realize the importance of belowground processes to plant productivity. We
analysed the resulting hand drawings by using mathematical modelling and
found root system parameters for a newly developed parametric L-System
model. In this way we were able to first reproduce the illustrations,
second computationally analyse root system traits and finally access the
dynamic root architecture development.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 575-587
Issue: 6
Volume: 16
Year: 2010
Month: 3
X-DOI: 10.1080/13873954.2010.491360
File-URL: http://hdl.handle.net/10.1080/13873954.2010.491360
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Handle: RePEc:taf:nmcmxx:v:16:y:2010:i:6:p:575-587
Template-Type: ReDIF-Article 1.0
Author-Name: Kurt Schlacher
Author-X-Name-First: Kurt
Author-X-Name-Last: Schlacher
Author-Name: Markus Schöberl
Author-X-Name-First: Markus
Author-X-Name-Last: Schöberl
Title: Modelling, analysis and control of distributed parameter systems
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 1-2
Issue: 1
Volume: 17
Year: 2011
Month: 1
X-DOI: 10.1080/13873954.2010.537507
File-URL: http://hdl.handle.net/10.1080/13873954.2010.537507
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Handle: RePEc:taf:nmcmxx:v:17:y:2011:i:1:p:1-2
Template-Type: ReDIF-Article 1.0
Author-Name: Markus Schöberl
Author-X-Name-First: Markus
Author-X-Name-Last: Schöberl
Author-Name: Kurt Schlacher
Author-X-Name-First: Kurt
Author-X-Name-Last: Schlacher
Title: First-order Hamiltonian field theory and mechanics
Abstract:
This article deals with the geometric analysis of the
evolutionary and the polysymplectic approach in first-order Hamiltonian
field theory. Based on a variational formulation in the Lagrangian
picture, two possible counterparts in a Hamiltonian formulation are
discussed. The main difference between these two approaches, which are
important for the application, is besides a different bundle construction,
the different Legendre transform as well as the analysis of the conserved
quantities. Furthermore, the role of the boundary conditions in the
Lagrangian and in the Hamiltonian pictures will be addressed. These
theoretical investigations will be completed by the analysis of several
examples, including the wave equation, a beam equation and a special
subclass of continuum mechanics in the presented framework.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 105-121
Issue: 1
Volume: 17
Year: 2010
Month: 4
X-DOI: 10.1080/13873954.2010.537526
File-URL: http://hdl.handle.net/10.1080/13873954.2010.537526
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Handle: RePEc:taf:nmcmxx:v:17:y:2010:i:1:p:105-121
Template-Type: ReDIF-Article 1.0
Author-Name: Hans Irschik
Author-X-Name-First: Hans
Author-X-Name-Last: Irschik
Author-Name: Johannes Gerstmayr
Author-X-Name-First: Johannes
Author-X-Name-Last: Gerstmayr
Title: A continuum-mechanics interpretation of Reissner's non-linear shear-deformable beam theory
Abstract:
This article deals with the non-linear modelling of beams
that are bent, sheared and stretched by external forces and moments. In
the following, we restrict to plane-deformations and static conditions.
Our task is to present a continuum mechanics-based interpretation of the
celebrated large displacement finite deformation structural mechanics
theory, which was presented by Eric Reissner [On one-dimensional
finite-strain beam theory: the plane problem, J. Appl. Math.
Phys. 23 (1972), pp. 795--804]. The latter formulation was restricted to
the notions of structural mechanics and thus did not use the notions of
stress and strain, which are fundamental for continuum mechanics. Thus,
the common continuum mechanics-based constitutive modelling at the
stress--strain level cannot be utilized in connection with Reissner's
original theory. Instead, Reissner suggested that constitutive relations
between certain generalized strains (bending, shear and axial force
strains) and generalized static entities (bending moments, shear and
normal forces) should be evaluated from physical experiments. This means
that the beam to be studied must be first built up, and the experiments
must be performed for the real beam as a whole. Although such physical
experiments are indeed to be performed in practice for safety reasons in
sensible cases, for example, bridge decks or aircraft wings, it is
nevertheless felt to be a drawback that the results of simple standardized
stress--strain experiments concerning the constitutive behaviour of the
materials, from which the beam is built up, cannot be used. Moreover,
relying only on physical experiments on the whole beam means that
computations (virtual experiments) can be made only after the beam has
been built up. To overcome this problem, we subsequently present a
continuum mechanics-based interpretation of Reissner's structural
mechanics modelling, by attaching a proper continuum mechanics-based
meaning to both the generalized static entities and the generalized
strains in Reissner's theory [E. Reissner, On one-dimensional
finite-strain beam theory: the plane problem, J. Appl. Math.
Phys. 23 (1972), pp. 795--804]. Consequently, these generalized static
entities can be related to the generalized strains on the basis of a
constitutive modelling on the stress--strain level. We show this in some
detail in this contribution for a hyperelastic material proposed by Simo
and Hughes [Computational Inelasticity, Springer, New
York, 1998]. An illustrative numerical example is given which shows the
results of large bending and axial deformation behaviour for different
constitutive relations. This article represents an extended version of a
preliminary work published in [H. Irschik and J. Gerstmayr, A
hyperelastic Reissner-type model for non-linear shear deformable
beams, Proceedings of the Mathmod 09 Vienna, I. Troch and F.
Breitenecker, eds., 2009, pp. 1--7].
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 19-29
Issue: 1
Volume: 17
Year: 2010
Month: 5
X-DOI: 10.1080/13873954.2010.537512
File-URL: http://hdl.handle.net/10.1080/13873954.2010.537512
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Handle: RePEc:taf:nmcmxx:v:17:y:2010:i:1:p:19-29
Template-Type: ReDIF-Article 1.0
Author-Name: Alessandro Macchelli
Author-X-Name-First: Alessandro
Author-X-Name-Last: Macchelli
Author-Name: Claudio Melchiorri
Author-X-Name-First: Claudio
Author-X-Name-Last: Melchiorri
Title: A formal method for improving the transient behaviour of a non-linear flexible link
Abstract:
This article presents a procedure for improving the transient
response of a boundary-controlled non-linear flexible elastic beam through
a feed-forward action. It is shown that it is possible to obtain a
formal analytic solution of an infinite-dimensional
linear system, which approximates the non-linear dynamics, under
time-varying boundary conditions in terms of the free vibration modes of
the structure, whose calculation is a relatively easy task. The
feed-forward action is then obtained by inverting the relationship between
input and output variables. A numerical example is presented and some
simulation results are discussed.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 3-18
Issue: 1
Volume: 17
Year: 2010
Month: 4
X-DOI: 10.1080/13873954.2010.537508
File-URL: http://hdl.handle.net/10.1080/13873954.2010.537508
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Handle: RePEc:taf:nmcmxx:v:17:y:2010:i:1:p:3-18
Template-Type: ReDIF-Article 1.0
Author-Name: Thomas Rittenschober
Author-X-Name-First: Thomas
Author-X-Name-Last: Rittenschober
Title: Compensation of harmonic disturbances in piezoelastic structures
Abstract:
The use of self-sensing piezoelectric actuators in smart
structures means collocation of actuator and sensor. The measured electric
current carries contributions from an electrical and mechanical subsystem.
The latter contribution is due to the direct piezoelectric effect that is
used for the purpose of vibration control. This procedure requires the
robust separation of the electric current due to the direct piezoelectric
effect from the measured electric current. Due to the unfavourable ratio
of these two signals, the design of an observer for the electric current
due to the direct piezoelectric effect is proposed. The control design for
the purpose of harmonic disturbance suppression is based on an internal
model approach and is facilitated by the special structure of the
underlying mathematical model. Stability issues with respect to the
distributed parameter system are resolved by applying the concepts of
passivity and
stability in conjunction with the small gain theorem.
The control concept is evaluated by exciting the piezoelastic structure
under investigation at a dominant eigenfrequency.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 31-48
Issue: 1
Volume: 17
Year: 2010
Month: 4
X-DOI: 10.1080/13873954.2010.537514
File-URL: http://hdl.handle.net/10.1080/13873954.2010.537514
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Handle: RePEc:taf:nmcmxx:v:17:y:2010:i:1:p:31-48
Template-Type: ReDIF-Article 1.0
Author-Name: Mathias Bachmayer
Author-X-Name-First: Mathias
Author-X-Name-Last: Bachmayer
Author-Name: Heinz Ulbrich
Author-X-Name-First: Heinz
Author-X-Name-Last: Ulbrich
Author-Name: Joachim Rudolph
Author-X-Name-First: Joachim
Author-X-Name-Last: Rudolph
Title: Flatness-based control of a horizontally moving erected beam with a point mass
Abstract:
A mechanism consisting of a horizontally moving cart that
carries an erected flexible beam with a point mass -- as occurring in
placement machines or stacker cranes -- is considered. An explicitly
parametrized feed-forward control law is designed using a flatness-based
approach. Nominally, this control law allows one to perform fast placement
motions although avoiding residual oscillations at the arrival. The
efficiency of this approach and sensitivity with respect to parametric
uncertainties are investigated numerically using both finite element and
finite difference models. An experimental set-up is presented and some
experimental results demonstrate the usefulness of the approach.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 49-69
Issue: 1
Volume: 17
Year: 2010
Month: 4
X-DOI: 10.1080/13873954.2010.537517
File-URL: http://hdl.handle.net/10.1080/13873954.2010.537517
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Handle: RePEc:taf:nmcmxx:v:17:y:2010:i:1:p:49-69
Template-Type: ReDIF-Article 1.0
Author-Name: Eugenio Fortaleza
Author-X-Name-First: Eugenio
Author-X-Name-Last: Fortaleza
Author-Name: Yann Creff
Author-X-Name-First: Yann
Author-X-Name-Last: Creff
Author-Name: Jean Lévine
Author-X-Name-First: Jean
Author-X-Name-Last: Lévine
Title: Active control of a dynamically positioned vessel for the installation of subsea structures
Abstract:
This article presents an active control dedicated to a
re-entry problem found in the offshore oil industry. The re-entry
operation consists of connecting the bottom end of a very long pipeline to
the wellhead, by dynamically modifying the pipeline top-end position,
which is linked to a dynamically positioned vessel (DPV). Such long
pipelines are usually called risers, because they are used to make the
drilling mud or the hydrocarbons rise from the wellhead to the platform.
Nowadays, the re-entry operation is often done manually. The use of an
active control intends to reduce the operation time and to make it
possible even under bad weather conditions. The considered subsea
structure can be viewed as a cable submerged in a flow and modelled by the
Bernoulli's cable equation, completed with a damping factor, that linearly
depends on the structure speed. After some simplifications that are
justified in our context, the corresponding model turns out to be
differentially flat, a useful property for control design, providing an
extension of previous works.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 71-84
Issue: 1
Volume: 17
Year: 2010
Month: 5
X-DOI: 10.1080/13873954.2010.537519
File-URL: http://hdl.handle.net/10.1080/13873954.2010.537519
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Handle: RePEc:taf:nmcmxx:v:17:y:2010:i:1:p:71-84
Template-Type: ReDIF-Article 1.0
Author-Name: Redha Moulla
Author-X-Name-First: Redha
Author-X-Name-Last: Moulla
Author-Name: Laurent Lefèvre
Author-X-Name-First: Laurent
Author-X-Name-Last: Lefèvre
Author-Name: Bernhard Maschke
Author-X-Name-First: Bernhard
Author-X-Name-Last: Maschke
Title: Geometric pseudospectral method for spatial integration of dynamical systems
Abstract:
A reduction method that preserves geometric structure and
energetic properties of non-linear distributed parameter systems is
presented. It is stated as a general pseudospectral method using
approximation spaces generated by polynomials bases. It applies to
Hamiltonian formulations of distributed parameter systems that may be
derived for hyperbolic systems (wave equation, beam model, shallow water
model) as well as for parabolic ones (heat or diffusion equations,
reaction--diffusion models). It is defined in order to preserve the
geometric symplectic interconnection structure (Stokes--Dirac structure)
of the infinite-dimensional model by performing exact differentiation and
by a suitable choice of port variables. This leads to a reduced
port-controlled Hamiltonian finite-dimensional system of ordinary
differential equations. Moreover, the stored and dissipated power in the
reduced model are approximations of the distributed ones. The method thus
allows the direct use of thermodynamics phenomenological constitutive
equations for the design of passivity-based or energy-shaping control
techniques.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 85-104
Issue: 1
Volume: 17
Year: 2010
Month: 4
X-DOI: 10.1080/13873954.2010.537524
File-URL: http://hdl.handle.net/10.1080/13873954.2010.537524
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Handle: RePEc:taf:nmcmxx:v:17:y:2010:i:1:p:85-104
Template-Type: ReDIF-Article 1.0
Author-Name: Peter Benner
Author-X-Name-First: Peter
Author-X-Name-Last: Benner
Author-Name: Jens Saak
Author-X-Name-First: Jens
Author-X-Name-Last: Saak
Title: Efficient balancing-based MOR for large-scale second-order systems
Abstract:
Large-scale structure dynamics models arise in all areas
where vibrational analysis is performed, ranging from control of machine
tools to microsystems simulation. To reduce computational and resource
demands and be able to compute solutions and controls in acceptable, that
is, applicable, time frames, model order reduction (MOR) is applied.
Classically modal truncation is used for this task. The reduced-order
models (ROMs) generated are often relatively large and often need manual
modification by the addition of certain technically motivated modes. That
means they are at least partially heuristic and cannot be generated fully
automatic. Here, we will consider the application of fully
automatic balancing-based MOR techniques. Our main focus will be on
presenting a way to efficiently compute the ROM exploiting the sparsity
and second-order structure of the finite element method (FEM)
semi-discretization, following a reduction technique originally presented
in [V. Chahlaoui, K.A. Gallivan, A. Vandendorpe, and P. Van Dooren, Model
reduction of second-order system, in Dimension Reduction of Large-Scale
Systems, P. Benner, V. Mehrmann, and D. Sorensen, eds., Lecture Notes in
Computer Science and Engineering, Vol. 45, Springer Verlag, Berlin, 2005,
pp. 149--172], [Y. Chahlaoui, D. Lemonnier, A. Vandendorpe, and P. Van
Dooren, Second-order balanced truncation, Linear Algebra Appl. 415 (2006),
pp. 373--384], [T. Reis and T. Stykel, Balanced truncation model reduction
of second-order systems, Math. Comput. Model. Dyn. Syst. 14 (2008), pp.
391--406] and [J. Fehr, P. Eberhard, and M. Lehner, Improving the
Reduction Process in Flexible Multibody Dynamics by the Use of 2nd Order
Position Gramian Matrices, Proceedings ENOC, St. Petersburg, Russia,
2008]. Large-scale sparse solvers for the underlying matrix equations
solved in the balancing process are adapted to the second-order structure
of the equations and the suitability of our approach is demonstrated for
two practical examples.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 123-143
Issue: 2
Volume: 17
Year: 2010
Month: 11
X-DOI: 10.1080/13873954.2010.540822
File-URL: http://hdl.handle.net/10.1080/13873954.2010.540822
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Handle: RePEc:taf:nmcmxx:v:17:y:2010:i:2:p:123-143
Template-Type: ReDIF-Article 1.0
Author-Name: Bernard Haasdonk
Author-X-Name-First: Bernard
Author-X-Name-Last: Haasdonk
Author-Name: Mario Ohlberger
Author-X-Name-First: Mario
Author-X-Name-Last: Ohlberger
Title: Efficient reduced models and a posteriori error estimation for parametrized dynamical systems by offline/online decomposition
Abstract:
We address the problem of model order reduction (MOR) of
parametrized dynamical systems. Motivated by reduced basis (RB) methods
for partial differential equations, we show that some characteristic
components can be transferred to model reduction of parametrized linear
dynamical systems. We assume an affine parameter dependence of the system
components, which allows an offline/online decomposition and is the basis
for efficient reduced simulation. Additionally, error control is possible
by a posteriori error estimators for the state vector and
output vector, based on residual analysis and primal-dual techniques.
Experiments demonstrate the applicability of the reduced parametrized
systems, the reliability of the error estimators and the runtime gain by
the reduction technique. The a posteriori error
estimation technique can straightforwardly be applied to all traditional
projection-based reduction techniques of non-parametric and parametric
linear systems, such as model reduction, balanced truncation, moment
matching, proper orthogonal decomposition (POD) and so on.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 145-161
Issue: 2
Volume: 17
Year: 2009
Month: 12
X-DOI: 10.1080/13873954.2010.514703
File-URL: http://hdl.handle.net/10.1080/13873954.2010.514703
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Handle: RePEc:taf:nmcmxx:v:17:y:2009:i:2:p:145-161
Template-Type: ReDIF-Article 1.0
Author-Name: Othman M.K. Alsmadi
Author-X-Name-First: Othman M.K.
Author-X-Name-Last: Alsmadi
Author-Name: Zaer S. Abo-Hammour
Author-X-Name-First: Zaer S.
Author-X-Name-Last: Abo-Hammour
Author-Name: Adnan M. Al-Smadi
Author-X-Name-First: Adnan M.
Author-X-Name-Last: Al-Smadi
Author-Name: Dia I. Abu-Al-Nadi
Author-X-Name-First: Dia I.
Author-X-Name-Last: Abu-Al-Nadi
Title: Genetic algorithm approach with frequency selectivity for model order reduction of MIMO systems
Abstract:
A novel genetic algorithm (GA) approach with frequency
selectivity advantage for model order reduction (MOR) of
multi-input--multi-output (MIMO) systems is presented in this article.
Motivated by singular perturbation and other reduction techniques, the new
MOR method is formulated using GAs, which can be applied to
single-input--single-output (SISO)- or MIMO-type systems. The GA procedure
is based on maximizing the fitness function corresponding to the response
deviation between the full-order model and the reduced-order model with
the option of substructure preservation. The proposed GA-MOR method is
compared to the well-known reduction techniques, such as the Schur
decomposition balanced truncation, proper orthogonal decomposition (POD)
and state elimination through balancing-related frequency-weighted
realization in addition to other recent methods. Simulation results
validate the superiority and robustness of the new MOR technique as it can
search the solution space for almost optimal solutions.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 163-181
Issue: 2
Volume: 17
Year: 2010
Month: 11
X-DOI: 10.1080/13873954.2010.540806
File-URL: http://hdl.handle.net/10.1080/13873954.2010.540806
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Handle: RePEc:taf:nmcmxx:v:17:y:2010:i:2:p:163-181
Template-Type: ReDIF-Article 1.0
Author-Name: J.-Emeterio Navarro-Barrientos
Author-X-Name-First: J.-Emeterio
Author-X-Name-Last: Navarro-Barrientos
Author-Name: Daniel E. Rivera
Author-X-Name-First: Daniel E.
Author-X-Name-Last: Rivera
Author-Name: Linda M. Collins
Author-X-Name-First: Linda M.
Author-X-Name-Last: Collins
Title: A dynamical model for describing behavioural interventions for weight loss and body composition change
Abstract:
We present a dynamical model incorporating both physiological
and psychological factors that predict changes in body mass and
composition during the course of a behavioural intervention for weight
loss. The model consists of a three-compartment energy balance integrated
with a mechanistic psychological model inspired by the Theory of Planned
Behaviour. This describes how important variables in a behavioural
intervention can influence healthy eating habits and increased physical
activity over time. The novelty of the approach lies in representing the
behavioural intervention as a dynamical system and the integration of the
psychological and energy balance models. Two simulation scenarios are
presented that illustrate how the model can improve the understanding of
how changes in intervention components and participant differences affect
outcomes. Consequently, the model can be used to inform behavioural
scientists in the design of optimized interventions for weight loss and
body composition change.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 183-203
Issue: 2
Volume: 17
Year: 2010
Month: 8
X-DOI: 10.1080/13873954.2010.520409
File-URL: http://hdl.handle.net/10.1080/13873954.2010.520409
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Handle: RePEc:taf:nmcmxx:v:17:y:2010:i:2:p:183-203
Template-Type: ReDIF-Article 1.0
Author-Name: Yongbo Chen
Author-X-Name-First: Yongbo
Author-X-Name-Last: Chen
Author-Name: Oliver Lenord
Author-X-Name-First: Oliver
Author-X-Name-Last: Lenord
Author-Name: Robert Michel
Author-X-Name-First: Robert
Author-X-Name-Last: Michel
Author-Name: Alexander Schmitt
Author-X-Name-First: Alexander
Author-X-Name-Last: Schmitt
Author-Name: Dieter Schramm
Author-X-Name-First: Dieter
Author-X-Name-Last: Schramm
Title: Modelling of electromechanical systems with switch circuits by using transmission elements
Abstract:
The modelling via transmission elements,
which was originally introduced to model the kinematics and dynamics of
multi-body systems, is applied to modelling electric drive systems with
switch circuits in this article. This approach is implemented in
C++ in the simulation software
Drive&Control D&C
Engine which is designed to model and simulate mechatronic
systems in the drive engineering by the department of advanced engineering
of the Bosch Rexroth AG. The switch elements, used in the
power converters of electric drive systems, are treated as ideal switches
and are described in an efficient, stable way. Discontinuities caused by
the ideal switch models are dealt with an event-handling algorithm. The
application example is a complete permanent-magnet-synchronous-motor
(PMSM) drive system. A benchmark simulation is carried out to demonstrate
this approach's performance in terms of computational time and accuracy.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 205-219
Issue: 2
Volume: 17
Year: 2010
Month: 6
X-DOI: 10.1080/13873954.2010.502029
File-URL: http://hdl.handle.net/10.1080/13873954.2010.502029
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Handle: RePEc:taf:nmcmxx:v:17:y:2010:i:2:p:205-219
Template-Type: ReDIF-Article 1.0
Author-Name: Thomas Schmickl
Author-X-Name-First: Thomas
Author-X-Name-Last: Schmickl
Author-Name: Heiko Hamann
Author-X-Name-First: Heiko
Author-X-Name-Last: Hamann
Author-Name: Karl Crailsheim
Author-X-Name-First: Karl
Author-X-Name-Last: Crailsheim
Title: Modelling a hormone-inspired controller for individual- and multi-modular robotic systems
Abstract:
For all living organisms, the ability to regulate internal
homeostasis is a crucial feature. This ability to control variables around
a set point is found frequently in the physiological networks of single
cells and of higher organisms. Also, nutrient allocation and task
selection in social insect colonies can be interpreted as homeostatic
processes of a super-organism. And finally, behaviour can also represent
such a control scheme. We show how a simple model of hormone regulation,
inspired by simple biological organisms, can be used as a novel method to
control the behaviour of autonomous robots. We demonstrate the formulation
of such an artificial homeostatic hormone system (AHHS) by a set of linked
difference equations and explain how the homeostatic control of behaviour
is achieved by homeostatic control of the internal
‘hormonal’ state of the robot. The first task that we used
to check the quality of our AHHS controllers was a very simple one, which
is often a core functionality in controller programmes that are used in
autonomous robots: obstacle avoidance. We demonstrate two implementations
of such an AHHS controller that performs this task in differing levels of
quality. Both controllers use the concept of homeostatic control of
internal variables (hormones) and they extend this concept to also include
the outside world of the robots into the controlling feedback loops: As
they try to regulate internal hormone levels, they are forced to keep a
homeostatic control of sensor values in a way that the desired goal
‘obstacle avoidance’ is achieved. Thus, the created
behaviour is also a manifestation of the acts of homeostatic control. The
controllers were evaluated using a stock-and-flow model that allowed
sensitivity analysis and stability tests. Afterwards, we have also tested
both controllers in a multi-agent simulation tool, which allowed us to
predict the robots' behaviours in various habitats and group sizes.
Finally, we demonstrate how this novel AHHS controller is suitable to
control a multi-cellular robotic organism in an evolutionary robotics
approach, which is used for self-programming in a gait-learning task.
These examples shown in this article represent the first step in our
research towards autonomous aggregation and coordination of robots to
higher-level modular robotic organisms that consist of several joined
autonomous robotic units. Finally, we plan to achieve such aggregation
patterns and to control complex-shaped robotic organisms using AHHS
controllers, as they are described here.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 221-242
Issue: 3
Volume: 17
Year: 2010
Month: 12
X-DOI: 10.1080/13873954.2011.557862
File-URL: http://hdl.handle.net/10.1080/13873954.2011.557862
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Handle: RePEc:taf:nmcmxx:v:17:y:2010:i:3:p:221-242
Template-Type: ReDIF-Article 1.0
Author-Name: I. Emrah Nikerel
Author-X-Name-First: I. Emrah
Author-X-Name-Last: Nikerel
Author-Name: André B. Canelas
Author-X-Name-First: André B.
Author-X-Name-Last: Canelas
Author-Name: Stefan J. Jol
Author-X-Name-First: Stefan J.
Author-X-Name-Last: Jol
Author-Name: Peter J.T. Verheijen
Author-X-Name-First: Peter J.T.
Author-X-Name-Last: Verheijen
Author-Name: Joseph J. Heijnen
Author-X-Name-First: Joseph J.
Author-X-Name-Last: Heijnen
Title: Construction of kinetic models for metabolic reaction networks: Lessons learned in analysing short-term stimulus response data
Abstract:
Construction of dynamic models of large-scale metabolic
networks is one of the central issues in the engineering of living cells.
However, construction of such models is often hampered by a number of
challenges, for example, data availability, compartmentalization and
parameter identification coupled with design of in vivo
perturbations. As a solution to the latter, short-term perturbation
experiments are proposed and are proven to be a useful experimental method
to obtain insights into the in vivo kinetic properties of
the metabolic pathways. The aim of this work is to construct a
kinetic model using the available experimental data obtained by short-term
perturbation experiments, where the steady state of a glucose-limited
anaerobic chemostat culture of Saccharomyces cerevisiae
was perturbed. In constructing the model, we first determined the
steady-state flux distribution using the data before the glucose pulse and
the known stoichiometry. For the rate expressions, we used approximative
linlog kinetics, which allows the enzyme--metabolite kinetic interactions
to be represented by an elasticity matrix. We performed a
priori model reduction based on timescale analysis and parameter
identifiability analysis allowing the information content of the
experimental data to be assessed. The final values of the elasticities are
estimated by fitting the model to the available short-term kinetic
response data. The final model consists of 16 metabolites and
14 reactions. With 25 parameters, the model adequately describes the
short-term response of the cells to the glucose perturbation, pointing to
the fact that the assumed kinetic interactions in the model are sufficient
to account for the observed response.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 243-260
Issue: 3
Volume: 17
Year: 2010
Month: 12
X-DOI: 10.1080/13873954.2010.548167
File-URL: http://hdl.handle.net/10.1080/13873954.2010.548167
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Handle: RePEc:taf:nmcmxx:v:17:y:2010:i:3:p:243-260
Template-Type: ReDIF-Article 1.0
Author-Name: Fabio Chiara
Author-X-Name-First: Fabio
Author-X-Name-Last: Chiara
Author-Name: Junmin Wang
Author-X-Name-First: Junmin
Author-X-Name-Last: Wang
Author-Name: Chinmaya B. Patil
Author-X-Name-First: Chinmaya B.
Author-X-Name-Last: Patil
Author-Name: Ming-Feng Hsieh
Author-X-Name-First: Ming-Feng
Author-X-Name-Last: Hsieh
Author-Name: Fengjun Yan
Author-X-Name-First: Fengjun
Author-X-Name-Last: Yan
Title: Development and experimental validation of a control-oriented Diesel engine model for fuel consumption and brake torque predictions
Abstract:
This article describes the development and experimental
validation of a control-oriented, real-time capable, Diesel engine
instantaneous fuel consumption and brake torque model under warmed-up
conditions with only two inputs: torque request and the engine speed and
no other measurements. Such a model, with the capability of reliably and
computationally efficiently estimating the aforementioned variables at
both steady-state and transient engine-operating conditions, can be
utilized in the context of real-time control and optimization of hybrid
power train systems. Although Diesel engine dynamics are highly non-linear
and very complex, by considering the Diesel engine and its control system,
that is, engine control unit together as an entity, it becomes possible to
predict the engine instantaneous fuel consumption and torque based on only
those two inputs. A synergy between different modelling methodologies
including physically based grey-box and data-driven black-box approaches
were integrated in the Diesel engine model. The fuelling and torque
predictions have been validated by means of experimental data from a
medium-duty Diesel engine at both steady-state and transient operations,
including engine start-ups and shutdowns.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 261-277
Issue: 3
Volume: 17
Year: 2011
Month: 1
X-DOI: 10.1080/13873954.2011.562902
File-URL: http://hdl.handle.net/10.1080/13873954.2011.562902
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Handle: RePEc:taf:nmcmxx:v:17:y:2011:i:3:p:261-277
Template-Type: ReDIF-Article 1.0
Author-Name: Ortwin Farle
Author-X-Name-First: Ortwin
Author-X-Name-Last: Farle
Author-Name: Stefan Burgard
Author-X-Name-First: Stefan
Author-X-Name-Last: Burgard
Author-Name: Romanus Dyczij-Edlinger
Author-X-Name-First: Romanus
Author-X-Name-Last: Dyczij-Edlinger
Title: Passivity preserving parametric model-order reduction for non-affine parameters
Abstract:
Parametric model-order reduction (pMOR) has become a
well-established technology for analysing large-scale systems with
multiple parameters. However, the treatment of non-affine parameters is
still posing significant challenges, because projection-based
order-reduction methods cannot be applied directly. A common remedy is to
establish affine parameter-dependencies approximately, but present
extraction methods do not take important system properties, such as
passivity, into account. This article proposes a new order-reduction
approach that preserves passivity, reciprocity and causality and applies
to a wide class of linear time-invariant (LTI) systems. We present the
theory of the suggested method and demonstrate its practical usefulness by
numerical examples taken from computational electromagnetics.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 279-294
Issue: 3
Volume: 17
Year: 2010
Month: 12
X-DOI: 10.1080/13873954.2011.562901
File-URL: http://hdl.handle.net/10.1080/13873954.2011.562901
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Handle: RePEc:taf:nmcmxx:v:17:y:2010:i:3:p:279-294
Template-Type: ReDIF-Article 1.0
Author-Name: Bernard Haasdonk
Author-X-Name-First: Bernard
Author-X-Name-Last: Haasdonk
Author-Name: Boris Lohmann
Author-X-Name-First: Boris
Author-X-Name-Last: Lohmann
Title: Special Issue on “Model Order Reduction of Parameterized Problems”
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 295-296
Issue: 4
Volume: 17
Year: 2011
Month: 8
X-DOI: 10.1080/13873954.2011.547661
File-URL: http://hdl.handle.net/10.1080/13873954.2011.547661
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Handle: RePEc:taf:nmcmxx:v:17:y:2011:i:4:p:295-296
Template-Type: ReDIF-Article 1.0
Author-Name: U. Baur
Author-X-Name-First: U.
Author-X-Name-Last: Baur
Author-Name: P. Benner
Author-X-Name-First: P.
Author-X-Name-Last: Benner
Author-Name: A. Greiner
Author-X-Name-First: A.
Author-X-Name-Last: Greiner
Author-Name: J.G. Korvink
Author-X-Name-First: J.G.
Author-X-Name-Last: Korvink
Author-Name: J. Lienemann
Author-X-Name-First: J.
Author-X-Name-Last: Lienemann
Author-Name: C. Moosmann
Author-X-Name-First: C.
Author-X-Name-Last: Moosmann
Title: Parameter preserving model order reduction for MEMS applications
Abstract:
Model order reduction techniques are known to work reliably
for finite element-type simulations of micro-electro-mechanical systems
devices. These techniques can tremendously shorten computational times for
transient and harmonic analyses. However, standard model reduction
techniques cannot be applied if the equation system incorporates
time-varying matrices or parameters that are to be preserved for the
reduced model. However, design cycles often involve parameter
modification, which should remain possible also in the reduced model. In
this article we demonstrate a novel parameterization method to numerically
construct highly accurate parametric ordinary differential equation
systems based on a small number of systems with different parameter
settings. This method is demonstrated to parameterize the geometry of a
model of a micro-gyroscope, where the relative error introduced by the
parameterization lies in the region of
. We also present recent developments on semi-automatic
order reduction methods that can preserve scalar parameters or functions
during the reduction process. The first approach is based on a
multivariate Padé-type expansion. The second approach is a coupling of the
balanced truncation method for model order reduction of (deterministic)
linear, time-invariant systems with interpolation. The approach is quite
flexible in allowing the use of numerous interpolation techniques like
polynomial, Hermite, rational, sinc and spline interpolation. As technical
examples we investigate a micro anemometer as well as the gyroscope.
Speed-up factors of 20--80 could be achieved, while retaining up to six
parameters and keeping typical relative errors below 1%.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 297-317
Issue: 4
Volume: 17
Year: 2010
Month: 8
X-DOI: 10.1080/13873954.2011.547658
File-URL: http://hdl.handle.net/10.1080/13873954.2011.547658
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Handle: RePEc:taf:nmcmxx:v:17:y:2010:i:4:p:297-317
Template-Type: ReDIF-Article 1.0
Author-Name: Rudy Eid
Author-X-Name-First: Rudy
Author-X-Name-Last: Eid
Author-Name: Rosa Castañé-Selga
Author-X-Name-First: Rosa
Author-X-Name-Last: Castañé-Selga
Author-Name: Heiko Panzer
Author-X-Name-First: Heiko
Author-X-Name-Last: Panzer
Author-Name: Thomas Wolf
Author-X-Name-First: Thomas
Author-X-Name-Last: Wolf
Author-Name: Boris Lohmann
Author-X-Name-First: Boris
Author-X-Name-Last: Lohmann
Title: Stability-preserving parametric model reduction by matrix interpolation
Abstract:
In this article, a method to preserve stability in parametric
model reduction by matrix interpolation is presented. Based on the matrix
measure approach, sufficient conditions on the original system matrices
are derived. Once they are fulfilled, the stability of each of the reduced
models is guaranteed as well as that of the parametric model resulting
from interpolation. In addition, it is shown that these sufficient
conditions are met by port-Hamiltonian systems and by a relevant set of
second-order systems obtained by the finite element method. The new
approach is illustrated by two numerical examples.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 319-335
Issue: 4
Volume: 17
Year: 2010
Month: 11
X-DOI: 10.1080/13873954.2011.547671
File-URL: http://hdl.handle.net/10.1080/13873954.2011.547671
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Handle: RePEc:taf:nmcmxx:v:17:y:2010:i:4:p:319-335
Template-Type: ReDIF-Article 1.0
Author-Name: Saifon Chaturantabut
Author-X-Name-First: Saifon
Author-X-Name-Last: Chaturantabut
Author-Name: Danny C. Sorensen
Author-X-Name-First: Danny C.
Author-X-Name-Last: Sorensen
Title: Application of POD and DEIM on dimension reduction of non-linear miscible viscous fingering in porous media
Abstract:
A discrete empirical interpolation method (DEIM) is applied
in conjunction with proper orthogonal decomposition (POD) to construct a
non-linear reduced-order model of a finite difference discretized system
used in the simulation of non-linear miscible viscous fingering in a 2-D
porous medium. POD is first applied to extract a low-dimensional basis
that optimally captures the dominant characteristics of the system
trajectory. This basis is then used in a Galerkin projection scheme to
construct a reduced-order system. DEIM is then applied to greatly improve
the efficiency in computing the projected non-linear terms in the POD
reduced system. DEIM achieves a complexity reduction of the
non-linearities, which is proportional to the number of reduced variables,
whereas POD retains a complexity proportional to the original number of
variables. Numerical results demonstrate that the dynamics of the viscous
fingering in the full-order system of dimension 15,000 can be captured
accurately by the POD--DEIM reduced system of dimension 40 with the
computational time reduced by factor of
.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 337-353
Issue: 4
Volume: 17
Year: 2010
Month: 7
X-DOI: 10.1080/13873954.2011.547660
File-URL: http://hdl.handle.net/10.1080/13873954.2011.547660
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Handle: RePEc:taf:nmcmxx:v:17:y:2010:i:4:p:337-353
Template-Type: ReDIF-Article 1.0
Author-Name: Timo Tonn
Author-X-Name-First: Timo
Author-X-Name-Last: Tonn
Author-Name: K. Urban
Author-X-Name-First: K.
Author-X-Name-Last: Urban
Author-Name: S. Volkwein
Author-X-Name-First: S.
Author-X-Name-Last: Volkwein
Title: Comparison of the reduced-basis and POD a posteriori error estimators for an elliptic linear-quadratic optimal control problem
Abstract:
In this article, a linear-quadratic optimal control problem
governed by the Helmholtz equation is considered. For the computation of
suboptimal solutions, two different model reduction techniques are
compared: the reduced-basis method and proper orthogonal decomposition. By
an a posteriori error estimator for the optimal control
problem, the accuracy of the suboptimal solutions is ensured. The
efficiency of both model reduction approaches is illustrated by a
numerical example for the stationary Helmholtz equation.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 355-369
Issue: 4
Volume: 17
Year: 2010
Month: 7
X-DOI: 10.1080/13873954.2011.547678
File-URL: http://hdl.handle.net/10.1080/13873954.2011.547678
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Handle: RePEc:taf:nmcmxx:v:17:y:2010:i:4:p:355-369
Template-Type: ReDIF-Article 1.0
Author-Name: Fabrizio Gelsomino
Author-X-Name-First: Fabrizio
Author-X-Name-Last: Gelsomino
Author-Name: Gianluigi Rozza
Author-X-Name-First: Gianluigi
Author-X-Name-Last: Rozza
Title: Comparison and combination of reduced-order modelling techniques in 3D parametrized heat transfer problems
Abstract:
Reduced basis method has successfully been used in 2D to
solve heat transfer parametrized problems. In this work, we present some
3D applications in the same field. We consider two problems, the steady
Thermal Fin and the time-dependent Graetz
Flow, we compare two reduced-order modelling techniques:
Reduced basis and Proper orthogonal
decomposition, then we apply a combination of the two strategies
in the time-dependent case.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 371-394
Issue: 4
Volume: 17
Year: 2010
Month: 6
X-DOI: 10.1080/13873954.2011.547672
File-URL: http://hdl.handle.net/10.1080/13873954.2011.547672
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Handle: RePEc:taf:nmcmxx:v:17:y:2010:i:4:p:371-394
Template-Type: ReDIF-Article 1.0
Author-Name: Jens L. Eftang
Author-X-Name-First: Jens L.
Author-X-Name-Last: Eftang
Author-Name: David J. Knezevic
Author-X-Name-First: David J.
Author-X-Name-Last: Knezevic
Author-Name: Anthony T. Patera
Author-X-Name-First: Anthony T.
Author-X-Name-Last: Patera
Title: An hp certified reduced basis method for parametrized parabolic partial differential equations
Abstract:
In this article, we introduce an hp
certified reduced basis (RB) method for parabolic partial differential
equations. We invoke a Proper Orthogonal Decomposition (POD) (in
time)/Greedy (in parameter) sampling procedure first in the initial
partition of the parameter domain (h-refinement) and
subsequently in the construction of RB approximation spaces restricted to
each parameter subdomain (p-refinement). We show that
proper balance between additional POD modes and additional parameter
values in the initial subdivision process guarantees convergence of the
approach. We present numerical results for two model problems: linear
convection--diffusion and quadratically non-linear Boussinesq natural
convection. The new procedure is significantly faster (more costly) in the
RB Online (Offline) stage.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 395-422
Issue: 4
Volume: 17
Year: 2010
Month: 9
X-DOI: 10.1080/13873954.2011.547670
File-URL: http://hdl.handle.net/10.1080/13873954.2011.547670
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Handle: RePEc:taf:nmcmxx:v:17:y:2010:i:4:p:395-422
Template-Type: ReDIF-Article 1.0
Author-Name: Bernard Haasdonk
Author-X-Name-First: Bernard
Author-X-Name-Last: Haasdonk
Author-Name: Markus Dihlmann
Author-X-Name-First: Markus
Author-X-Name-Last: Dihlmann
Author-Name: Mario Ohlberger
Author-X-Name-First: Mario
Author-X-Name-Last: Ohlberger
Title: A training set and multiple bases generation approach for parameterized model reduction based on adaptive grids in parameter space
Abstract:
Modern simulation scenarios require real-time or many-query
responses from a simulation model. This is the driving force for increased
efforts in model order reduction for high-dimensional dynamical systems or
partial differential equations. This demand for fast simulation models is
even more critical for parameterized problems. Several snapshot-based
methods for basis construction exist for parameterized model order
reduction, for example, proper orthogonal decomposition or reduced basis
methods. They require the careful choice of samples for generation of the
reduced model. In this article we address two types of grid-based
adaptivity that can be beneficial in such basis generation procedures.
First, we describe an approach for training set
adaptivity. Second, we introduce an approach for multiple bases
on adaptive parameter domain partitions. Due to the
modularity, both methods also can easily be combined. They result in
efficient reduction schemes with accelerated training times, improved
approximation properties and control on the reduced basis size. We
demonstrate the applicability of the approaches for instationary partial
differential equations and parameterized dynamical systems.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 423-442
Issue: 4
Volume: 17
Year: 2010
Month: 11
X-DOI: 10.1080/13873954.2011.547674
File-URL: http://hdl.handle.net/10.1080/13873954.2011.547674
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Handle: RePEc:taf:nmcmxx:v:17:y:2010:i:4:p:423-442
Template-Type: ReDIF-Article 1.0
Author-Name: David J. Knezevic
Author-X-Name-First: David J.
Author-X-Name-Last: Knezevic
Title: Reduced basis approximation and a posteriori error estimates for a multiscale liquid crystal model
Abstract:
We present a reduced basis framework and associated a
posteriori error estimates for the multiscale Stokes
Fokker--Planck system that governs the flow of a dilute suspension of
rod-like molecules immersed in a Newtonian solvent, relevant in liquid
crystals modelling. The Fokker--Planck equation dictates the microscale
behaviour and must be solved at every quadrature point of the macroscale
finite element mesh -- this is a natural example of a
many-query problem for which the certified reduced basis
method is well suited. We focus on a Poiseuille flow problem to simplify
the presentation of ideas, but we note that the methods developed in this
article generalize directly to more complicated problems. Numerical
results demonstrate that our reduced basis approach leads to significant
computational savings and also that our error estimator performs well for
moderate parameter values.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 443-461
Issue: 4
Volume: 17
Year: 2010
Month: 6
X-DOI: 10.1080/13873954.2011.547676
File-URL: http://hdl.handle.net/10.1080/13873954.2011.547676
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Handle: RePEc:taf:nmcmxx:v:17:y:2010:i:4:p:443-461
Template-Type: ReDIF-Article 1.0
Author-Name: Carsten Hartmann
Author-X-Name-First: Carsten
Author-X-Name-Last: Hartmann
Title: Balanced model reduction of partially observed Langevin equations: an averaging principle
Abstract:
We study balanced model reduction of partially observed
stochastic differential equations of Langevin type. Upon balancing, the
Langevin equation turns into a singularly perturbed system of equations
with slow and fast degrees of freedom. We prove that in the limit of
vanishing small Hankel singular values (i.e. for infinite scale separation
between fast and slow variables), its solution converges to the solution
of a reduced-order Langevin equation. The approach is illustrated with
several numerical examples, and we discuss the relation to model reduction
of deterministic control systems having an underlying Hamiltonian
structure.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 463-490
Issue: 5
Volume: 17
Year: 2011
Month: 3
X-DOI: 10.1080/13873954.2011.576517
File-URL: http://hdl.handle.net/10.1080/13873954.2011.576517
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Handle: RePEc:taf:nmcmxx:v:17:y:2011:i:5:p:463-490
Template-Type: ReDIF-Article 1.0
Author-Name: Astrid M. Cappuyns
Author-X-Name-First: Astrid M.
Author-X-Name-Last: Cappuyns
Author-Name: Linde J. Debor
Author-X-Name-First: Linde J.
Author-X-Name-Last: Debor
Author-Name: Ilse Y. Smets
Author-X-Name-First: Ilse Y.
Author-X-Name-Last: Smets
Author-Name: Dirk Springael
Author-X-Name-First: Dirk
Author-X-Name-Last: Springael
Author-Name: Leen Bastiaens
Author-X-Name-First: Leen
Author-X-Name-Last: Bastiaens
Author-Name: Jan F. Van Impe
Author-X-Name-First: Jan F.
Author-X-Name-Last: Van Impe
Title: Modelling methyl tertiary butyl ether and tertiary butyl alcohol biodegradation by a bacterial consortium
Abstract:
The widespread use of methyl tertiary butyl ether (MTBE) as
an additive in gasoline has resulted in serious soil and groundwater
pollution. To tackle MTBE contamination in groundwater, bioremediation is
considered a cost-effective and energy-efficient option. The design of an
efficient, reliable and reproducible bioremediation strategy requires a
thorough understanding of the (microbial) degradation kinetics of both
MTBE and tertiary butyl alcohol (TBA), that is, the main intermediate
during bioremediation of MTBE. To assist the design procedure, this
research focuses on building a mathematical model to describe MTBE/TBA
degradation kinetics by a bacterial consortium, that is, the VITO
M-consortium. For the presented case study, the information
obtained from experimental data is combined with knowledge regarding the
biodegradation reactions in order to obtain a low-complexity, accurate
mathematical model. The resulting model accurately describes MTBE/TBA
degradation and has successfully been validated on independent
experimental data. Since the model is of the mass balance type, it can
easily be extended to other types of operation by defining the transport
terms of the new system. This makes the model a very useful tool in the
design procedure for large-scale bioremediation strategies. Furthermore,
the model provides insight into the MTBE/TBA degradation kinetics and
biodegradation mechanisms by hypothesis testing.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 491-500
Issue: 5
Volume: 17
Year: 2011
Month: 3
X-DOI: 10.1080/13873954.2011.577077
File-URL: http://hdl.handle.net/10.1080/13873954.2011.577077
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Handle: RePEc:taf:nmcmxx:v:17:y:2011:i:5:p:491-500
Template-Type: ReDIF-Article 1.0
Author-Name: Shu Wang
Author-X-Name-First: Shu
Author-X-Name-Last: Wang
Author-Name: Hisatoshi Sakura
Author-X-Name-First: Hisatoshi
Author-X-Name-Last: Sakura
Author-Name: Aditya Kasarekar
Author-X-Name-First: Aditya
Author-X-Name-Last: Kasarekar
Title: Numerical modelling and analysis of external gear pumps by applying generalized control volumes
Abstract:
Components in gear pumps usually involve complex geometrical
arrangements in order to achieve the desired performance. The use of
lumped parametric models is considered the most accurate and effective
method for investigation of the associated design issues. In this study,
the numerical modelling approach based on the lumped parameters and
control volume concepts is reviewed, especially for gear teeth within the
meshing zone. To apply the approach to the entire gear pump, control
volume concepts are generalized to all gear pockets and flow orifices with
some reasonable assumptions. The assumptions include instantaneous angular
positions, orifice transitions and imagined control volumes with internal
flows. The fluid dynamics and pump performance, which even have the
measurement difficulties, can be estimated to investigate and optimize the
design parameters of gears by the model. A simulation example and its
experimental results of a gear machine are presented to validate the
proposed approach in this article.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 501-513
Issue: 5
Volume: 17
Year: 2011
Month: 3
X-DOI: 10.1080/13873954.2011.577556
File-URL: http://hdl.handle.net/10.1080/13873954.2011.577556
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Handle: RePEc:taf:nmcmxx:v:17:y:2011:i:5:p:501-513
Template-Type: ReDIF-Article 1.0
Author-Name: David J. Murray-Smith
Author-X-Name-First: David J.
Author-X-Name-Last: Murray-Smith
Title: Feedback methods for inverse simulation of dynamic models for engineering systems applications
Abstract:
Inverse simulation is a form of inverse modelling in which
computer simulation methods are used to find the time histories of input
variables that, for a given model, match a set of required output
responses. Conventional inverse simulation methods for dynamic models are
computationally intensive and can present difficulties for high-speed
applications. This article includes a review of established methods of
inverse simulation, giving some emphasis on iterative techniques that were
first developed for aeronautical applications. It goes on to discuss the
application of a different approach that is based on feedback principles.
This feedback method is suitable for a wide range of linear and non-linear
dynamic models and involves two distinct stages. The first stage involves
design of a feedback loop around the given simulation model, and in the
second stage, that closed-loop system is used for inversion of the model.
Issues of robustness within closed-loop systems used in inverse simulation
are not significant as there are no plant uncertainties or external
disturbances. Thus, the process is simpler than that required for the
development of a control system of equivalent complexity. Engineering
applications of this feedback approach to inverse simulation are described
through case studies that put particular emphasis on non-linear and
multi-input multi-output models.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 515-541
Issue: 5
Volume: 17
Year: 2011
Month: 4
X-DOI: 10.1080/13873954.2011.584323
File-URL: http://hdl.handle.net/10.1080/13873954.2011.584323
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Handle: RePEc:taf:nmcmxx:v:17:y:2011:i:5:p:515-541
Template-Type: ReDIF-Article 1.0
Author-Name: Marco Bonvini
Author-X-Name-First: Marco
Author-X-Name-Last: Bonvini
Author-Name: Alberto Leva
Author-X-Name-First: Alberto
Author-X-Name-Last: Leva
Title: Object-oriented sub-zonal modelling for efficient energy-related building simulation
Abstract:
When modelling and simulating a building to evaluate its
energy-related performance, reproducing the behaviour of the contained air
volumes is very important. For that purpose, fully mixed models (i.e. for
instance, a single temperature per room) easily prove inadequate, while
computational fluid dynamics ones do not provide sufficient simulation
speed, and are difficult to formulate and manage in a modular manner. This
manuscript presents a somehow intermediate solution based on the
object-oriented modelling paradigm, and implemented in the Modelica
language. The proposal advantages are illustrated by two significant
examples.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 543-559
Issue: 6
Volume: 17
Year: 2011
Month: 5
X-DOI: 10.1080/13873954.2011.592143
File-URL: http://hdl.handle.net/10.1080/13873954.2011.592143
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Handle: RePEc:taf:nmcmxx:v:17:y:2011:i:6:p:543-559
Template-Type: ReDIF-Article 1.0
Author-Name: Nadine Jung
Author-X-Name-First: Nadine
Author-X-Name-Last: Jung
Author-Name: Anthony T. Patera
Author-X-Name-First: Anthony T.
Author-X-Name-Last: Patera
Author-Name: Bernard Haasdonk
Author-X-Name-First: Bernard
Author-X-Name-Last: Haasdonk
Author-Name: Boris Lohmann
Author-X-Name-First: Boris
Author-X-Name-Last: Lohmann
Title: Model order reduction and error estimation with an application to the parameter-dependent eddy current equation
Abstract:
In product development, engineers simulate the underlying
partial differential equation many times with commercial tools for
different geometries. Since the available computation time is limited, we
look for reduced models with an error estimator that guarantees the
accuracy of the reduced model. Using commercial tools the theoretical
methods proposed by G. Rozza, D.B.P. Huynh and A.T. Patera
[Reduced basis approximation and a posteriori error estimation for
affinely parameterized elliptic coercive partial differential
equations, Arch. Comput. Methods Eng. 15 (2008), pp. 229--275]
lead to technical difficulties. We present how to overcome these
challenges and validate the error estimator by applying it to a simple
model of a solenoid actuator that is a part of a valve.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 561-582
Issue: 6
Volume: 17
Year: 2011
Month: 4
X-DOI: 10.1080/13873954.2011.582120
File-URL: http://hdl.handle.net/10.1080/13873954.2011.582120
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Template-Type: ReDIF-Article 1.0
Author-Name: Houbao Xu
Author-X-Name-First: Houbao
Author-X-Name-Last: Xu
Title: Modelling and well-posed analysis for software system with rejuvenation
Abstract:
Software rejuvenation, as an effective policy to enhance the
performance of software system, has been discussed broadly with the
hypothesis that the software system being well posed. A system being well
posed means that the dynamical solution not only exists and is unique but
also is stable, which means the dynamical solution converges to steady
solution as time tends to infinity. To enrich the theory basis of the
software system, and to simulate the dynamical solution which is also an
instantaneous availability of the software system with rejuvenation, this
article models the behaviour of software system by a group of ordinary and
partial equations. With the theory of strong continuous semigroup, this
article proves that the system is well posed. As a result, the expression
and simulation of instantaneous availability of the system is presented.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 583-600
Issue: 6
Volume: 17
Year: 2011
Month: 5
X-DOI: 10.1080/13873954.2011.588607
File-URL: http://hdl.handle.net/10.1080/13873954.2011.588607
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Handle: RePEc:taf:nmcmxx:v:17:y:2011:i:6:p:583-600
Template-Type: ReDIF-Article 1.0
Author-Name: Hana Baili
Author-X-Name-First: Hana
Author-X-Name-Last: Baili
Title: Optimal filtering of piecewise deterministic processes for source detection and separation in electric load monitoring
Abstract:
We wish to compute in discrete real time the best estimate
for the composition of the total active power recorded at a customer's
house, without any intrusion. A new solution for online characterization
of the electric load is proposed. The solution is based on issues from the
applied stochastic analysis of Markov processes. We specifically suggest
that optimal filtering of a hybrid stochastic differential system covers
entirely the detection and separation subproblems underlying the main
problem.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 601-616
Issue: 6
Volume: 17
Year: 2011
Month: 5
X-DOI: 10.1080/13873954.2011.591174
File-URL: http://hdl.handle.net/10.1080/13873954.2011.591174
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Handle: RePEc:taf:nmcmxx:v:17:y:2011:i:6:p:601-616
Template-Type: ReDIF-Article 1.0
Author-Name: Heiko Hamann
Author-X-Name-First: Heiko
Author-X-Name-Last: Hamann
Author-Name: Thomas Schmickl
Author-X-Name-First: Thomas
Author-X-Name-Last: Schmickl
Title: Modelling the swarm: Analysing biological and engineered swarm systems
Abstract:
In this article, we discuss the current research efforts on
swarm systems and on the motivation of mathematical modelling of such
distributed and self-organizing systems. Obviously, a special emphasis is
given to those articles which were carefully selected for the special
issue at hand. These articles demonstrate how mathematical models of
different kinds -- bottom-up agent models and top-down model approaches --
increase the understanding of natural swarm systems, for example, by
investigating the efficiency in the self-regulation of social insect
colonies. A second group of articles illustrates how mathematical models
are used to generate and optimize artificial swarm systems as engineered
in the field of swarm robotics. We discuss the common problems of such
modelling efforts and highlight the importance of models as generators of
hypotheses that suggest novel empiric experiments as well as the
importance of empiric experimentation that results in meaningful model
parameterizations. In summary, the special issue at hand, which is
introduced by this article, gives a significant overview about the lines
of research that are followed in the research of swarm systems today.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 1-12
Issue: 1
Volume: 18
Year: 2011
Month: 6
X-DOI: 10.1080/13873954.2011.601426
File-URL: http://hdl.handle.net/10.1080/13873954.2011.601426
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:1:p:1-12
Template-Type: ReDIF-Article 1.0
Author-Name: Nicolas Bredeche
Author-X-Name-First: Nicolas
Author-X-Name-Last: Bredeche
Author-Name: Jean-Marc Montanier
Author-X-Name-First: Jean-Marc
Author-X-Name-Last: Montanier
Author-Name: Wenguo Liu
Author-X-Name-First: Wenguo
Author-X-Name-Last: Liu
Author-Name: Alan F.T. Winfield
Author-X-Name-First: Alan F.T.
Author-X-Name-Last: Winfield
Title: Environment-driven distributed evolutionary adaptation in a population of autonomous robotic agents
Abstract:
This article is concerned with a fixed-size population of
autonomous agents facing unknown, possibly changing, environments. The
motivation is to design an embodied evolutionary algorithm that can cope
with the implicit fitness function hidden in the environment so as to
provide adaptation in the long run at the level of population. The
proposed algorithm, termed mEDEA, is shown to be both efficient in unknown
environments and robust to abrupt and unpredicted changes in the
environment. The emergence of consensus towards specific behavioural
strategies is examined, with a particular focus on algorithmic stability.
Finally, a real-world implementation of the algorithm is described with a
population of 20 real-world e-puck robots.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 101-129
Issue: 1
Volume: 18
Year: 2011
Month: 6
X-DOI: 10.1080/13873954.2011.601425
File-URL: http://hdl.handle.net/10.1080/13873954.2011.601425
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:1:p:101-129
Template-Type: ReDIF-Article 1.0
Author-Name: Istvan Karsai
Author-X-Name-First: Istvan
Author-X-Name-Last: Karsai
Author-Name: Andrew Runciman
Author-X-Name-First: Andrew
Author-X-Name-Last: Runciman
Title: The ‘common stomach’ as information source for the regulation of construction behaviour of the swarm
Abstract:
The construction of nests in insect societies requires
building materials, pulp and water foragers, builders and also an
organized workforce for effective construction. The central hypothesis of
this study is that wasp societies developed a social crop, or common
stomach, which stores water and provides a mechanism for worker
connectivity, which in turn regulates construction behaviour. Inspired by
the construction behaviour of social wasps, an agent-based model is
presented to show that via the usage of the common stomach, larger
colonies enjoy the benefit of having highly effective foragers, while most
of the swarm stays on the nest and only a few engage in highly risky
foraging trips. We also demonstrate how colony efficiency changes as a
function of colony size and the constitution of the labour distribution,
as well as how indirect interactions can increase efficiency of labour in
wasp societies.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 13-24
Issue: 1
Volume: 18
Year: 2011
Month: 5
X-DOI: 10.1080/13873954.2011.601423
File-URL: http://hdl.handle.net/10.1080/13873954.2011.601423
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:1:p:13-24
Template-Type: ReDIF-Article 1.0
Author-Name: Serge Kernbach
Author-X-Name-First: Serge
Author-X-Name-Last: Kernbach
Author-Name: Valentin A. Nepomnyashchikh
Author-X-Name-First: Valentin A.
Author-X-Name-Last: Nepomnyashchikh
Author-Name: Tanya Kancheva
Author-X-Name-First: Tanya
Author-X-Name-Last: Kancheva
Author-Name: Olga Kernbach
Author-X-Name-First: Olga
Author-X-Name-Last: Kernbach
Title: Specialization and generalization of robot behaviour in swarm energy foraging
Abstract:
Energy supply is one of the most serious problems for
micro-mechatronic devices. For collective systems, such as sensor networks
or swarms of autonomous micro-robots, collective energy management is
especially hard. This work describes a kinetic model of energy foraging
and an application of bio-inspired harvesting behaviour to a real robot
swarm. The heuristic strategy derived allows proper collective management
of energy resources without using global knowledge and guarantees a good
swarm efficiency. Despite the whole swarm having the same behavioural
rules, some robots specialize in only a few foraging activities, whereas
others are more universal in their behaviour. Such emergence of
‘specialists’ and ‘generalists’ is observed in
animal groups and can indicate common behavioural principles underlying
natural and artificial systems.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 131-152
Issue: 1
Volume: 18
Year: 2011
Month: 5
X-DOI: 10.1080/13873954.2011.601421
File-URL: http://hdl.handle.net/10.1080/13873954.2011.601421
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:1:p:131-152
Template-Type: ReDIF-Article 1.0
Author-Name: Anna Dornhaus
Author-X-Name-First: Anna
Author-X-Name-Last: Dornhaus
Title: Finding optimal collective strategies using individual-based simulations: colony organization in social insects
Abstract:
Social insects like ants and bees live in cooperative
colonies containing up to millions of individuals. These colonies are
sometimes termed ‘superorganisms’ and have evolved tightly
integrated and sophisticated collective behaviours. Different species,
however, often differ in the type and mechanisms of communication and
collective organization employed. I show here how individual-based models
can be used to identify the non-intuitive benefits of different mechanisms
of communication and division of labour and how these benefits may depend
on the external environment as well as traits of the society itself. This
allows us to understand under what ecological conditions particular types
of collective organization may have evolved, and thus can also help to
explain variation among species.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 25-37
Issue: 1
Volume: 18
Year: 2011
Month: 5
X-DOI: 10.1080/13873954.2011.601422
File-URL: http://hdl.handle.net/10.1080/13873954.2011.601422
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:1:p:25-37
Template-Type: ReDIF-Article 1.0
Author-Name: Heiko Hamann
Author-X-Name-First: Heiko
Author-X-Name-Last: Hamann
Author-Name: Thomas Schmickl
Author-X-Name-First: Thomas
Author-X-Name-Last: Schmickl
Author-Name: Karl Crailsheim
Author-X-Name-First: Karl
Author-X-Name-Last: Crailsheim
Title: Self-organized pattern formation in a swarm system as a transient phenomenon of non-linear dynamics
Abstract:
This article presents a microscopic model (agent positions,
directions and interactions are explicitly modelled) of mobile agents (or
self-propelled particles) that is inspired by the ‘complex
transport networks’ reported by Jones (2010; The emergence
and dynamical evolution of complex transport networks from simple
low-level behaviours, International Journal of Unconventional
Computing 6, pp. 125--144). Here, the agents' positions are modelled
continuously. This multi-agent system (or artificial swarm) shows a wide
variety of self-organized pattern formations. The self-organization is
based on the non-linearity of the agents' turns (discrete jumps in the
agents' directions) and the indirect interactions of the agents via a
potential field that determines their motion (high values are attractive)
and which is changed by themselves (agents increase the value of the
potential field at their positions). At least most of the irregular and
complex patterns are transient. The patterns found during the transient
are more complex than those the system converges to. Still, this transient
behaviour is relevant. We empirically investigate the transient times in
dependence of several system parameters and give examples.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 39-50
Issue: 1
Volume: 18
Year: 2011
Month: 5
X-DOI: 10.1080/13873954.2011.601418
File-URL: http://hdl.handle.net/10.1080/13873954.2011.601418
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:1:p:39-50
Template-Type: ReDIF-Article 1.0
Author-Name: Maja Varga
Author-X-Name-First: Maja
Author-X-Name-Last: Varga
Author-Name: Stjepan Bogdan
Author-X-Name-First: Stjepan
Author-X-Name-Last: Bogdan
Author-Name: Marija Dragojević
Author-X-Name-First: Marija
Author-X-Name-Last: Dragojević
Author-Name: Damjan Miklić
Author-X-Name-First: Damjan
Author-X-Name-Last: Miklić
Title: Collective search and decision-making for target localization
Abstract:
In this article we investigate the properties of collective
search and decision-making in robotic swarm, inspired by a phenomena
witnessed in bio-societies. The task of the proposed robotic swarm,
comprising scouts and labourers, is to find the most hazardous target in a
predefined area. Since in the proposed scenario the time interval for
decision-making is predefined, robotic scouts have to detect targets
within a particular amount of time. Hence, in the first part of the
article, we define a model of scout movement that enhances the explored
area. As we want to keep the searching process as simple as possible, and
at the same time to mimic social insect behaviour, a particular type of
correlated random walk is used for exploration. The second part of the
article deals with modelling of the decision-making process in the robotic
swarm. Using random walk theory we determine under which circumstances all
agents (or a particular number of them) would be committed to the most
hazardous target at the moment when the predefined time interval for
decision-making expires.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 51-65
Issue: 1
Volume: 18
Year: 2011
Month: 6
X-DOI: 10.1080/13873954.2011.601424
File-URL: http://hdl.handle.net/10.1080/13873954.2011.601424
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:1:p:51-65
Template-Type: ReDIF-Article 1.0
Author-Name: Mark Read
Author-X-Name-First: Mark
Author-X-Name-Last: Read
Author-Name: Paul S. Andrews
Author-X-Name-First: Paul S.
Author-X-Name-Last: Andrews
Author-Name: Jon Timmis
Author-X-Name-First: Jon
Author-X-Name-Last: Timmis
Author-Name: Vipin Kumar
Author-X-Name-First: Vipin
Author-X-Name-Last: Kumar
Title: Techniques for grounding agent-based simulations in the real domain: a case study in experimental autoimmune encephalomyelitis
Abstract:
For computational agent-based simulation, to become a serious
tool for investigating biological systems requires the implications of
simulation-derived results to be appreciated in terms of the original
system. However, epistemic uncertainty regarding the exact nature of
biological systems can complicate the calibration of models and
simulations that attempt to capture their structure and behaviour, and can
obscure the interpretation of simulation-derived experimental results with
respect to the real domain. We present an approach to the calibration of
an agent-based model of experimental autoimmune encephalomyelitis (EAE), a
mouse proxy for multiple sclerosis (MS), which harnesses interaction
between a modeller and domain expert in mitigating uncertainty in the data
derived from the real domain. A novel uncertainty analysis technique is
presented that, in conjunction with a latin hypercube-based global
sensitivity analysis, can indicate the implications of epistemic
uncertainty in the real domain. These analyses may be considered in the
context of domain-specific knowledge to qualify the certainty placed on
the results of in silico experimentation.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 67-86
Issue: 1
Volume: 18
Year: 2011
Month: 5
X-DOI: 10.1080/13873954.2011.601419
File-URL: http://hdl.handle.net/10.1080/13873954.2011.601419
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:1:p:67-86
Template-Type: ReDIF-Article 1.0
Author-Name: Michael Bodi
Author-X-Name-First: Michael
Author-X-Name-Last: Bodi
Author-Name: Ronald Thenius
Author-X-Name-First: Ronald
Author-X-Name-Last: Thenius
Author-Name: Martina Szopek
Author-X-Name-First: Martina
Author-X-Name-Last: Szopek
Author-Name: Thomas Schmickl
Author-X-Name-First: Thomas
Author-X-Name-Last: Schmickl
Author-Name: Karl Crailsheim
Author-X-Name-First: Karl
Author-X-Name-Last: Crailsheim
Title: Interaction of robot swarms using the honeybee-inspired control algorithm BEECLUST
Abstract:
In this work we investigated how robust a robot swarm acts
against disturbances caused by another robot swarm, both using the
BEECLUST algorithm, which is inspired by honeybee behaviour. For our
investigation we simulated an environment with an ambient illuminance, a
light spot and a shadow spot. In such an environment we tested two
different castes of Jasmine III robots whereas each caste had to perform a
different task. One swarm aggregates at places of high illuminance (light
spot) and the other one at places of low illuminance (shadow spot). We
show that small swarm populations can benefit from the presence of another
robot swarm. Medium populated swarms are affected neither positively nor
negatively. Large swarm populations act robust against disturbances caused
by other robot swarms as long as no jamming effects occur. In this article
we show that the BEECLUST algorithm provides all features for making
collective decisions. Furthermore we show that the robustness of the
BEECLUST algorithm allows us to control a heterogeneous robot swarm in
environments which demand differing controller strategies and swarm
intelligent behaviour.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 87-100
Issue: 1
Volume: 18
Year: 2011
Month: 5
X-DOI: 10.1080/13873954.2011.601420
File-URL: http://hdl.handle.net/10.1080/13873954.2011.601420
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:1:p:87-100
Template-Type: ReDIF-Article 1.0
Author-Name: Tom Arne Pedersen
Author-X-Name-First: Tom Arne
Author-X-Name-Last: Pedersen
Author-Name: Eilif Pedersen
Author-X-Name-First: Eilif
Author-X-Name-Last: Pedersen
Title: Bond graph modelling of marine power systems
Abstract:
The main motivation for writing this article is to develop a
model library for an All-Electric Ship that gives an opportunity to
simulate both existing and new machinery systems without having to remodel
the entire system each time. The model library should support the process
of modelling and reuse, while also emphasizing openness to brace the
modeller during the development and refinement phase. The bond graph
approach is good when it comes to the physical modelling of systems and is
a good tool for combining different energy domains to better help in
understanding the system. In addition, a bond graph is a powerful method
to find dependencies between various components. Using a causal analysis,
any problems in the model, for example, algebraic constrains or dependent
system variables, will be detected, and the necessary remodelling may be
performed to handle such problems. The bond graph approach is therefore
used when developing the component library. The component library consists
of selected power producers such as diesel and gas engines, fuel cell and
synchronous generator and power consumers such as asynchronous motor with
a voltage source converter in addition to a generic load used for hotel
and auxiliary loads. The library also consists of a ship model and
propeller models.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 153-173
Issue: 2
Volume: 18
Year: 2011
Month: 7
X-DOI: 10.1080/13873954.2011.603735
File-URL: http://hdl.handle.net/10.1080/13873954.2011.603735
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:2:p:153-173
Template-Type: ReDIF-Article 1.0
Author-Name: Payam Zarafshan
Author-X-Name-First: Payam
Author-X-Name-Last: Zarafshan
Author-Name: S. Ali A. Moosavian
Author-X-Name-First: S. Ali A.
Author-X-Name-Last: Moosavian
Title: Rigid--flexible interactive dynamics modelling approach
Abstract:
Dynamics modelling of multi-body systems composed of rigid
and flexible elements is elaborated in this article. The control of such
systems is highly complicated due to severe underactuated conditions
caused by flexible elements and an inherent uneven non-linear dynamics.
Therefore, developing a compact dynamics model with the requirement of
limited computations is extremely useful for controller design, simulation
studies for design improvement and also practical implementations. In this
article, the rigid--flexible interactive dynamics modelling (RFIM)
approach is proposed as a combination of Lagrange and Newton--Euler
methods, in which the motion equations of rigid and flexible members are
separately developed in an explicit closed form. These equations are then
assembled and solved simultaneously at each time step by considering the
mutual interaction and constraint forces. The proposed approach yields a
compact model rather than a common accumulation approach that leads to a
massive set of equations in which the dynamics of flexible elements is
united with the dynamics equations of rigid members. The proposed RFIM
approach is first detailed for multi-body systems with flexible joints,
and then with flexible members. Then, to reveal the merits of this new
approach, few case studies are presented. A flexible inverted pendulum is
studied first as a simple template for lucid comparisons, and next a space
free-flying robotic system that contains a rigid main body equipped with
two manipulating arms and two flexible solar panels is considered.
Modelling verification of this complicated system is vigorously performed
using ANSYS and ADAMS programs. The obtained results reveal the outcome
accuracy of the new proposed approach for explicit dynamics modelling of
rigid--flexible multi-body systems such as mobile robotic systems, while
its limited computations provide an efficient tool for controller design,
simulation studies and also practical implementations of model-based
algorithms.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 175-199
Issue: 2
Volume: 18
Year: 2011
Month: 7
X-DOI: 10.1080/13873954.2011.608166
File-URL: http://hdl.handle.net/10.1080/13873954.2011.608166
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:2:p:175-199
Template-Type: ReDIF-Article 1.0
Author-Name: Za'er S. Abo-Hammour
Author-X-Name-First: Za'er S.
Author-X-Name-Last: Abo-Hammour
Author-Name: Othman M.K. Alsmadi
Author-X-Name-First: Othman M.K.
Author-X-Name-Last: Alsmadi
Author-Name: Adnan M. Al-Smadi
Author-X-Name-First: Adnan M.
Author-X-Name-Last: Al-Smadi
Author-Name: Maha I. Zaqout
Author-X-Name-First: Maha I.
Author-X-Name-Last: Zaqout
Author-Name: Mohammad S. Saraireh
Author-X-Name-First: Mohammad S.
Author-X-Name-Last: Saraireh
Title: ARMA model order and parameter estimation using genetic algorithms
Abstract:
A new method for simultaneously determining the order and the
parameters of autoregressive moving average (ARMA) models is presented in
this article. Given an ARMA (p, q) model
in the absence of any information for the order, the correct order of the
model (p, q) as well as the correct
parameters will be simultaneously determined using genetic algorithms
(GAs). These algorithms simply search the order and the parameter spaces
to detect their correct values using the GA operators. The proposed method
works on the principle of maximizing the GA fitness value relying on the
deviation between the actual plant output, with or without an additive
noise, and the estimated plant output. Simulation results show in detail
the efficiency of the proposed approach. In addition to that, a practical
model identification and parameter estimation is conducted in this article
with results obtained as desired. The new method is compared with other
well-known methods for ARMA model order and parameter estimation.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 201-221
Issue: 2
Volume: 18
Year: 2011
Month: 8
X-DOI: 10.1080/13873954.2011.614068
File-URL: http://hdl.handle.net/10.1080/13873954.2011.614068
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:2:p:201-221
Template-Type: ReDIF-Article 1.0
Author-Name: Chun-Yue Chen
Author-X-Name-First: Chun-Yue
Author-X-Name-Last: Chen
Author-Name: Yao-Lin Jiang
Author-X-Name-First: Yao-Lin
Author-X-Name-Last: Jiang
Author-Name: Hai-Bao Chen
Author-X-Name-First: Hai-Bao
Author-X-Name-Last: Chen
Title: An -embedding model-order reduction approach for differential-algebraic equation systems
Abstract:
In this article, we present a model-order reduction (MOR)
approach for a large-scale linear differential-algebraic equation (DAE)
system. This MOR approach is accomplished in two steps: First, by applying
an
-embedding method, we approximate a DAE system with an
ordinary differential equation (ODE) system which has an artificial
parameter
Next, we use the Krylov subspace and balanced truncation
methods to reduce the resulting ODE system. Some important properties for
linear systems, such as stability and passivity, have been analysed. The
effectiveness of our approach is also successfully illustrated through
numerical examples.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 223-241
Issue: 2
Volume: 18
Year: 2011
Month: 8
X-DOI: 10.1080/13873954.2011.614258
File-URL: http://hdl.handle.net/10.1080/13873954.2011.614258
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:2:p:223-241
Template-Type: ReDIF-Article 1.0
Author-Name: Phurich Ngamkong
Author-X-Name-First: Phurich
Author-X-Name-Last: Ngamkong
Author-Name: Pijit Kochcha
Author-X-Name-First: Pijit
Author-X-Name-Last: Kochcha
Author-Name: Kongpan Areerak
Author-X-Name-First: Kongpan
Author-X-Name-Last: Areerak
Author-Name: Sarawut Sujitjorn
Author-X-Name-First: Sarawut
Author-X-Name-Last: Sujitjorn
Author-Name: Kongpol Areerak
Author-X-Name-First: Kongpol
Author-X-Name-Last: Areerak
Title: Applications of the generalized state-space averaging method to modelling of DC--DC power converters
Abstract:
Power converter models are time varying because of the
switching action of power electronic devices. To find time-invariant
models, this tutorial article presents the applications of the generalized
state-space averaging method to the modelling of a zeta converter feeding
a resistive load and paralleled buck converters driving a DC motor.
Simulations using the proposed models with MATLAB coding agree well with
the results of PSIM™ and SimPowerSystem™ of SIMULINK.
Beside, simulations using the proposed model reduce the simulation time by
64% as an average in comparison with the available software packages.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 243-260
Issue: 3
Volume: 18
Year: 2011
Month: 10
X-DOI: 10.1080/13873954.2011.635377
File-URL: http://hdl.handle.net/10.1080/13873954.2011.635377
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:3:p:243-260
Template-Type: ReDIF-Article 1.0
Author-Name: Yifan Zhao
Author-X-Name-First: Yifan
Author-X-Name-Last: Zhao
Author-Name: Daniel Coca
Author-X-Name-First: Daniel
Author-X-Name-Last: Coca
Author-Name: Stephen A. Billings
Author-X-Name-First: Stephen A.
Author-X-Name-Last: Billings
Author-Name: Yuzhu Guo
Author-X-Name-First: Yuzhu
Author-X-Name-Last: Guo
Author-Name: Rile I. Ristic
Author-X-Name-First: Rile I.
Author-X-Name-Last: Ristic
Author-Name: Lucy L. De Matos
Author-X-Name-First: Lucy L.
Author-X-Name-Last: De Matos
Author-Name: Andrew Dougherty
Author-X-Name-First: Andrew
Author-X-Name-Last: Dougherty
Title: Identification of radius-vector functions of interface evolution for star-shaped crystal growth
Abstract:
This article introduces a new method based on a radius-vector
function for identifying the spatio-temporal transition rule of
star-shaped crystal growth directly from experimental crystal growth
imaging data. From the morphology point of view, the growth is decomposed
as initial conditions, uniform growth and directional growth, which is
represented by a static polynomial model based on the Fourier expansion. A
recursive model is also introduced to help understand the dynamic
characteristics of the observed systems. The applicability of the proposed
approach is demonstrated using data from a simulation and from a real
crystal growth experiment.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 261-272
Issue: 3
Volume: 18
Year: 2011
Month: 12
X-DOI: 10.1080/13873954.2011.651475
File-URL: http://hdl.handle.net/10.1080/13873954.2011.651475
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:3:p:261-272
Template-Type: ReDIF-Article 1.0
Author-Name: Ercan Şenyiğit
Author-X-Name-First: Ercan
Author-X-Name-Last: Şenyiğit
Title: The optimization of lot sizing with supplier selection problem in multi-echelon defective supply chain network
Abstract:
A new problem called lot sizing with supplier selection
problem in the multi-product multi-echelon defective supply chain network
(MDSCN) is proposed in this study. We explain the problem by a case study.
We take the multi-product MDSCN of X enterprise into account. Back and
front engine blocks are products of X enterprise. The aim of this study is
to identify how many components will be purchased from which supplier
while meeting the demands of the customers for these two products. The
supply chain (SC) network of X enterprise is formed by mixed-integer
linear programming (MILP). The optimization of current SC network of X
enterprise is carried out by using Linear, INeractive, Discrete Optimizer
(LINDO) program. The customer expectations of X enterprise are met at the
highest level, and it gives the opportunity to have the knowledge, which
reduces the total cost, of purchasing--production--distribution strategy
with this work.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 273-286
Issue: 3
Volume: 18
Year: 2011
Month: 12
X-DOI: 10.1080/13873954.2011.654123
File-URL: http://hdl.handle.net/10.1080/13873954.2011.654123
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:3:p:273-286
Template-Type: ReDIF-Article 1.0
Author-Name: Wei Xia
Author-X-Name-First: Wei
Author-X-Name-Last: Xia
Author-Name: Yiping Yao
Author-X-Name-First: Yiping
Author-X-Name-Last: Yao
Author-Name: Xiaodong Mu
Author-X-Name-First: Xiaodong
Author-X-Name-Last: Mu
Title: An extended event graph-based modelling method for parallel and distributed discrete-event simulation
Abstract:
The developing logical process (LP)-based parallel and
distributed discrete-event simulation (PDES) in the existing PDES
programming environments is a difficult and time-consuming process. Event
graph is a simple and powerful modelling formalism of discrete-event
simulation, whereas this formalism does not support PDES. This article
proposes an extension of the event graph to consider the communication of
LPs via the events sent, which is called ‘extended event graph
(EEG)’, and proposes an EEG-based modelling method for PDES. This
modelling method shifts the focus of PDES development from writing code to
building models, and the system implementation can be automatically and
directly generated from EEG model. The experimental results show that EEG
models can successfully execute in the parallel simulator, and this
framework can effectively improve the PDES modelling activities.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 287-306
Issue: 3
Volume: 18
Year: 2012
Month: 1
X-DOI: 10.1080/13873954.2012.655697
File-URL: http://hdl.handle.net/10.1080/13873954.2012.655697
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Handle: RePEc:taf:nmcmxx:v:18:y:2012:i:3:p:287-306
Template-Type: ReDIF-Article 1.0
Author-Name: Alexander Schuster
Author-X-Name-First: Alexander
Author-X-Name-Last: Schuster
Author-Name: Martin Kozek
Author-X-Name-First: Martin
Author-X-Name-Last: Kozek
Author-Name: Bernhard Voglauer
Author-X-Name-First: Bernhard
Author-X-Name-Last: Voglauer
Author-Name: Andreas Voigt
Author-X-Name-First: Andreas
Author-X-Name-Last: Voigt
Title: Grey-box modelling of a viscose-fibre drying process
Abstract:
A dynamic model of a through-air-drying process for viscose
staple fibres is presented in this article. In this process fibres formed
to a porous web are transported through a convective dryer that consists
of numerous rotating drum sieves. Finally, the fibres pass through two
remoistening drums. The structure of the model is modular and scalable. On
applying spatial discretization the originally partial differential system
equations (conservation of mass and energy) turn into a system of ordinary
differential equations. Drying rates and heat transfer rates are
calculated using phenomenological equations for heat and mass transfer.
Kinetics of drying is separated into three phases, where viscose fibres
are hygroscopic. The process model is able to simulate transient behaviour
of the dryer like changes of the incoming fibre moisture, changes of the
drying air temperature and humidity and changes of the thickness of fibre
layer on the drums. Stationary validation of the longitudinal fibre
moisture distribution along the dryer shows good accordance with
measurement data at different operating points, for example, different
temperature profiles. Dynamic data like temperature transients are
utilized for both model fitting and validation of the dynamic model. For
the remoistening process and disturbance behaviour concerning the
thickness of the fibre web, black box models have been identified. Results
of a successful application of the model in a predictive control algorithm
are shown.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 307-325
Issue: 3
Volume: 18
Year: 2012
Month: 1
X-DOI: 10.1080/13873954.2012.662777
File-URL: http://hdl.handle.net/10.1080/13873954.2012.662777
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Handle: RePEc:taf:nmcmxx:v:18:y:2012:i:3:p:307-325
Template-Type: ReDIF-Article 1.0
Author-Name: Kurt Chudej
Author-X-Name-First: Kurt
Author-X-Name-Last: Chudej
Title: Modelling of fuel cells and chemical engineering applications
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 327-328
Issue: 4
Volume: 18
Year: 2011
Month: 10
X-DOI: 10.1080/13873954.2011.642386
File-URL: http://hdl.handle.net/10.1080/13873954.2011.642386
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:4:p:327-328
Template-Type: ReDIF-Article 1.0
Author-Name: Andreas Rauh
Author-X-Name-First: Andreas
Author-X-Name-Last: Rauh
Author-Name: Harald Aschemann
Author-X-Name-First: Harald
Author-X-Name-Last: Aschemann
Title: Parameter identification and observer-based control for distributed heating systems -- the basis for temperature control of solid oxide fuel cell stacks
Abstract:
The control of high-temperature fuel cell stacks is the
prerequisite to guarantee maximum efficiency and lifetime under both
constant and varying electrical load conditions. Especially, for
time-varying electrical load demands, it is necessary to develop novel
observer-based control approaches that are robust against parameter
uncertainties and disturbances that cannot be modelled a
priori. Since we aim at real-time applicability of these control
procedures, classical high-dimensional models -- which result from a
discretization of mathematical descriptions given by the partial
differential equations for heat and mass transfer -- cannot be applied.
Furthermore, these models have to be linked to the electrochemical
properties of the fuel cell. To reduce the order of these models to a
degree that allows us to use them in real-time, information on both the
temperature distribution in the fuel cell stack and the heat flow into its
interior due to electrochemical reactions is required. However, a direct
temperature measurement is not possible from a practical point of view.
For that reason, it is essential to reliably estimate the temperature
distribution and the heat flow on the basis of easily available measured
data. These data have to be available not only during development stages
but also in future series products. For such products, it is desirable to
reduce the number of sensors to improve the system's reliability and to
decrease the operating costs. The basic strategies that are applicable for
model-based open-loop and closed-loop control of heating systems as well
as for the identification of parameters, operating conditions and
disturbances as well as for state monitoring are summarized in this
article. They are demonstrated for exemplary set-ups in both simulation
and experiment.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 329-353
Issue: 4
Volume: 18
Year: 2011
Month: 10
X-DOI: 10.1080/13873954.2011.642384
File-URL: http://hdl.handle.net/10.1080/13873954.2011.642384
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:4:p:329-353
Template-Type: ReDIF-Article 1.0
Author-Name: Juergen O. Schumacher
Author-X-Name-First: Juergen O.
Author-X-Name-Last: Schumacher
Author-Name: Jens Eller
Author-X-Name-First: Jens
Author-X-Name-Last: Eller
Author-Name: Guido Sartoris
Author-X-Name-First: Guido
Author-X-Name-Last: Sartoris
Author-Name: Thibaut Colinart
Author-X-Name-First: Thibaut
Author-X-Name-Last: Colinart
Author-Name: Bernhard C. Seyfang
Author-X-Name-First: Bernhard C.
Author-X-Name-Last: Seyfang
Title: 2+1D modelling of a polymer electrolyte fuel cell with glassy-carbon microstructures
Abstract:
A computationally efficient model of a polymer electrolyte
fuel cell (PEFC) is presented, based on a 2+1D FEM modelling approach.
This approach is suitable to take the high aspect ratio between the
in-plane and the through-plane dimensions of fuel cells into account, and
to avoid expensive 3D calculations. The anode and cathode are described by
2D transport models. The coupling between the anode and cathode side is
established by a nonlinear point-to-point 1D model representing the
membrane electrode assembly (MEA). This 1D boundary value problem is
formulated using the computer algebra software Mathematica. The approach
is based on the symbolic weak form expressions of a nonlinear system of
PDEs. The integrands of the tangential element stiffness matrix and the
element residual vector of the coupled FEM problem are computed
analytically. These integrands are converted to C code automatically. The
model is applied to simulate a micro PEFC without gas diffusion layers
(GDLs). The simulations reveal an inhomogeneous in-plane electric current
density. Further, neutron radiography data obtained with the micro fuel
cell is compared to the calculated water flux between the 1D MEA model and
the 2D domains. The model is used to explain the locations where water
condensation is found.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 355-377
Issue: 4
Volume: 18
Year: 2011
Month: 11
X-DOI: 10.1080/13873954.2011.642390
File-URL: http://hdl.handle.net/10.1080/13873954.2011.642390
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:4:p:355-377
Template-Type: ReDIF-Article 1.0
Author-Name: Armin Rund
Author-X-Name-First: Armin
Author-X-Name-Last: Rund
Author-Name: Kurt Chudej
Author-X-Name-First: Kurt
Author-X-Name-Last: Chudej
Title: Optimal control for a simplified 1D fuel cell model
Abstract:
Molten carbonate fuel cells are a promising technology for
the operation of future stationary power plants. To enhance service life,
a detailed knowledge of their dynamical behaviour is essential. The
possibility of fast and save load changes is important for daily operation
of these power plants. To predict the dynamical behaviour of fuel cells a
hierachy of mathematical models has been developed in the past. Recently a
systematic model reduction was applied to a 2D crossflow model. We present
here the new 1D counterflow model and discuss a suitable discretization
method. Accordingly we set up a method of optimal control following the
first-discretize-then-optimize approach. Results are shown for simulation
and optimal control in the case of load changes.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 379-396
Issue: 4
Volume: 18
Year: 2011
Month: 10
X-DOI: 10.1080/13873954.2011.642389
File-URL: http://hdl.handle.net/10.1080/13873954.2011.642389
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:4:p:379-396
Template-Type: ReDIF-Article 1.0
Author-Name: Ilknur Disli
Author-X-Name-First: Ilknur
Author-X-Name-Last: Disli
Author-Name: Achim Kienle
Author-X-Name-First: Achim
Author-X-Name-Last: Kienle
Title: Systematic evaluation of models of different complexity for a low-density polyethylene plant
Abstract:
This study deals with the dynamic modelling and simulation of
low-density polyethylene (LDPE) production plant. LDPE is produced in a
complex process which takes place under extreme operating conditions and
may lead to nonlinear dynamics due to highly exothermic reactions and
material recycles around the reactor. In principle, the process is
represented by a distributed parameter system with an external coordinate
(the reactor length) and various internal coordinates (the chain length of
the polymer molecules, short- and long-chain branching and the number of
double bounds) resulting in a large scale model. In this contribution a
detailed reference model is introduced and possible model simplifications
are discussed systematically from on-line optimization and control point
of view.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 397-412
Issue: 4
Volume: 18
Year: 2011
Month: 11
X-DOI: 10.1080/13873954.2011.642383
File-URL: http://hdl.handle.net/10.1080/13873954.2011.642383
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:4:p:397-412
Template-Type: ReDIF-Article 1.0
Author-Name: René Schenkendorf
Author-X-Name-First: René
Author-X-Name-Last: Schenkendorf
Author-Name: Andreas Kremling
Author-X-Name-First: Andreas
Author-X-Name-Last: Kremling
Author-Name: Michael Mangold
Author-X-Name-First: Michael
Author-X-Name-Last: Mangold
Title: Influence of non-linearity to the Optimal Experimental Design demonstrated by a biological system
Abstract:
A precise estimation of parameters is essential to generate
mathematical models with a highly predictive power. A framework that
attempts to reduce parameter uncertainties caused by measurement errors is
known as Optimal Experimental Design (OED). The Fisher Information Matrix
(FIM), which is commonly used to define a cost function for OED, provides
at the best only a lower bound of parameter uncertainties for models that
are non-linear in their parameters. In this work, the Sigma Point method
is used instead, because it enables a more reliable approximation of the
parameter statistics accompanied by a manageable computational effort.
Moreover, it is shown that Sigma Points can also be used to define design
criteria for OED that incorporate the influence of parameter uncertainties
on the simulated model states, i.e. mean square error of prediction. To
reduce the computational effort of OED further, the Kriging Interpolation
approach is applied leading to an easily evaluable surrogate cost
function. The advantages of the Sigma Point method combined with the
Kriging Interpolation in the framework of OED are demonstrated for the
example of a biological two-substrate uptake model.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 413-426
Issue: 4
Volume: 18
Year: 2011
Month: 10
X-DOI: 10.1080/13873954.2011.642385
File-URL: http://hdl.handle.net/10.1080/13873954.2011.642385
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:4:p:413-426
Template-Type: ReDIF-Article 1.0
Author-Name: Mykhaylo Krasnyk
Author-X-Name-First: Mykhaylo
Author-X-Name-Last: Krasnyk
Author-Name: Christian Borchert
Author-X-Name-First: Christian
Author-X-Name-Last: Borchert
Author-Name: Michael Mangold
Author-X-Name-First: Michael
Author-X-Name-Last: Mangold
Title: Model reduction techniques for the simulation of particle populations in fluid flow
Abstract:
Crystallization processes are characterized by a close
interaction between particle formation and fluid flow. A detailed physical
description of these processes leads to complicated high-order models
whose numerical solution is challenging and expensive. For advanced
process control and other model-based online applications, reduced-order
models are required. In this work, a reduced model for a urea crystallizer
is developed using the method of moments for the internal coordinate and
proper orthogonal decomposition for the external coordinate. Simulations
are carried out to compare the reduced model with the detailed reference
model.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 427-438
Issue: 4
Volume: 18
Year: 2011
Month: 10
X-DOI: 10.1080/13873954.2011.642500
File-URL: http://hdl.handle.net/10.1080/13873954.2011.642500
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:4:p:427-438
Template-Type: ReDIF-Article 1.0
Author-Name: Georg Vossen
Author-X-Name-First: Georg
Author-X-Name-Last: Vossen
Author-Name: Jens Schüttler
Author-X-Name-First: Jens
Author-X-Name-Last: Schüttler
Title: Mathematical modelling and stability analysis for laser cutting
Abstract:
Mathematical modelling and stability analysis for the thermal
separation process of laser cutting will be considered. The process can be
modelled as a free boundary problem of non-linear 2D partial differential
equations with two moving boundaries describing the dynamical behaviour of
the arising melt flow. An approximate reduced 1D model will be derived by
asymptotic expansion methods. This model allows for linear stability
analysis of the system, which will be applied for different levels of
approximation qualities. The results are illustrated by numerical
simulation of the free boundary and the reduced problem.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 439-463
Issue: 4
Volume: 18
Year: 2011
Month: 10
X-DOI: 10.1080/13873954.2011.642387
File-URL: http://hdl.handle.net/10.1080/13873954.2011.642387
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:4:p:439-463
Template-Type: ReDIF-Article 1.0
Author-Name: Matthias Knauer
Author-X-Name-First: Matthias
Author-X-Name-Last: Knauer
Title: Fast and save container cranes as bilevel optimal control problems
Abstract:
For the use of container cranes in high rack warehouses,
reference trajectories can be obtained from optimal control problems in
order to control the swinging of the crane system during the fast movement
and in order to reach an equilibrium position at the end of the
trajectory. Safety requirements extend these problems to bilevel optimal
control problems, where the existence of alternative stop trajectories has
to be guaranteed. A method as to how these complex problems can be reduced
to conventional optimal control problems, even under control and state
constraints, is presented together with numerical examples.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 465-486
Issue: 4
Volume: 18
Year: 2011
Month: 10
X-DOI: 10.1080/13873954.2011.642388
File-URL: http://hdl.handle.net/10.1080/13873954.2011.642388
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Handle: RePEc:taf:nmcmxx:v:18:y:2011:i:4:p:465-486
Template-Type: ReDIF-Article 1.0
Author-Name: Cor-Jacques Kat
Author-X-Name-First: Cor-Jacques
Author-X-Name-Last: Kat
Author-Name: Pieter Schalk Els
Author-X-Name-First: Pieter Schalk
Author-X-Name-Last: Els
Title: Validation metric based on relative error
Abstract:
Engineers and scientists are often faced with the problem of
objectively comparing time histories of measured and/or simulated data.
This article presents a reliable and intuitive validation metric for use
in the validation process. The proposed validation metric is able to
quantify the agreement/disagreement between deterministic system response
quantities of interest obtained from measurements on a physical system and
predictions from a mathematical model. The validation metric is based on
the relative error, and the challenges concerning the use of the relative
error on periodic signals are addressed. The validation metric is compared
to similar metrics and their advantages and limitations are discussed. The
results show that the proposed validation metric gives a comprehensive
error that is able to quantify the agreement between two periodic signals
and is easily interpretable.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 487-520
Issue: 5
Volume: 18
Year: 2012
Month: 1
X-DOI: 10.1080/13873954.2012.663392
File-URL: http://hdl.handle.net/10.1080/13873954.2012.663392
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Handle: RePEc:taf:nmcmxx:v:18:y:2012:i:5:p:487-520
Template-Type: ReDIF-Article 1.0
Author-Name: John F. Moxnes
Author-X-Name-First: John F.
Author-X-Name-Last: Moxnes
Author-Name: Kjell Hausken
Author-X-Name-First: Kjell
Author-X-Name-Last: Hausken
Title: Mathematical modelling of acute virus influenza A infections
Abstract:
This article models the immune system and the virus dynamics
of acute influenza infection mathematically. We use the model to study the
virus dynamics of some well-known and severe and mild types of viruses.
Linkages to well-known models in the literature are illustrated.
Simulations are compared with experimental results in
vivo by comparing with results from infected ferrets where
infection closely resembles those in humans. Good agreement is achieved
between the model calculations and the experimental values for influenza A
viruses. For the Spanish flu virus H1N1 peak virus load is high and
virtually all cells are infected in the nostril. In general, the H1N1
viruses show much more prolonged infections than the H3N2 in the nostril.
We suggest that the reason is that unspecific immunity attacks H3N2-budded
viruses but not H1N1 viruses.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 521-538
Issue: 5
Volume: 18
Year: 2012
Month: 2
X-DOI: 10.1080/13873954.2012.669387
File-URL: http://hdl.handle.net/10.1080/13873954.2012.669387
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Handle: RePEc:taf:nmcmxx:v:18:y:2012:i:5:p:521-538
Template-Type: ReDIF-Article 1.0
Author-Name: Subhashis Chatterjee
Author-X-Name-First: Subhashis
Author-X-Name-Last: Chatterjee
Author-Name: Shobhit Nigam
Author-X-Name-First: Shobhit
Author-X-Name-Last: Nigam
Author-Name: Jeetendra Bahadur Singh
Author-X-Name-First: Jeetendra Bahadur
Author-X-Name-Last: Singh
Author-Name: Lakshmi Narayan Upadhyaya
Author-X-Name-First: Lakshmi Narayan
Author-X-Name-Last: Upadhyaya
Title: Effect of change point and imperfect debugging in software reliability and its optimal release policy
Abstract:
This article presents a software reliability growth model
based on non-homogeneous Poisson process. The main focus of this article
is to deliver a method for software reliability modelling incorporating
the concept of time-dependent fault introduction and fault removal rate
with change point. Also in this article, a cost model with change point
has been developed. Based on the cost model optimal release policy with
change point has been discussed. Maximum likelihood technique has been
applied to estimate the parameters of the model. The proposed model has
been validated using some real software failure data. Comparison has been
made with models incorporating change point and without change point. The
application of the proposed cost model has been shown using some numerical
examples.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 539-551
Issue: 5
Volume: 18
Year: 2012
Month: 3
X-DOI: 10.1080/13873954.2012.678011
File-URL: http://hdl.handle.net/10.1080/13873954.2012.678011
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Handle: RePEc:taf:nmcmxx:v:18:y:2012:i:5:p:539-551
Template-Type: ReDIF-Article 1.0
Author-Name: Stanislav Praček
Author-X-Name-First: Stanislav
Author-X-Name-Last: Praček
Author-Name: Klemen Možina
Author-X-Name-First: Klemen
Author-X-Name-Last: Možina
Author-Name: Franci Sluga
Author-X-Name-First: Franci
Author-X-Name-Last: Sluga
Title: Yarn motion during unwinding from packages
Abstract:
We study the motion of yarn modelled as a one-dimensional
inelastic string. In textile production, the yarn is being withdrawn from
cross-wound packages in warping and weft insertion. During unwinding,
there appear forces in the yarn that are approximately proportional to the
square of the unwinding velocity. The yarn tension is not constant, but it
oscillates within some interval. This is especially noticeable in over-end
unwinding from a static cross-wound package. Even when the yarn is not
strongly stressed, so that the tension never exceeds a few percent of the
breaking strength, the yarn can still break sometimes. The production
process requires as large warping and weaving speeds as possible;
therefore, it is necessary to improve our understanding of the cross-wound
package unwinding and to find the necessary modifications of the yarn
unwinding process. In addition to empirical tests, it has proved useful to
study yarn unwinding by mathematical modelling and computer simulations.
We state the equations of motion that describe the yarn unwinding and
develop a mathematical model that permits to simulate the process of
unwinding.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 553-569
Issue: 6
Volume: 18
Year: 2012
Month: 3
X-DOI: 10.1080/13873954.2012.674688
File-URL: http://hdl.handle.net/10.1080/13873954.2012.674688
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Handle: RePEc:taf:nmcmxx:v:18:y:2012:i:6:p:553-569
Template-Type: ReDIF-Article 1.0
Author-Name: Klemens G. Schulmeister
Author-X-Name-First: Klemens G.
Author-X-Name-Last: Schulmeister
Author-Name: Martin Kozek
Author-X-Name-First: Martin
Author-X-Name-Last: Kozek
Title: Modelling of lateral dynamics for an endless metal process belt
Abstract:
The subject of this article is the derivation of a model for
lateral dynamics of an endless metal process belt. The minimal
configuration of a process belt is a conveyor belt around two cylindrical
return drums. In order to ensure a plane surface, the metal belt is
pre-stressed to a high level. The main problem of this configuration is to
guarantee perfect lateral tracking of the belt utilizing swivelling and
tilting drum axes, which should guarantee a constant lateral position of
the belt under all process disturbances and geometric imperfections. A
dynamic process model in linear state space form is derived from simple
geometric parameters of the belt and drums. Measured data from a test rig
are utilized to estimate a parametric grey-box model, and both analytical
and experimental models are validated against experimental results. The
region of validity of the linear models is evaluated and the excellent
performance of the grey-box model is demonstrated. The application of this
model for control design is demonstrated for compensation of a lateral
process force.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 571-586
Issue: 6
Volume: 18
Year: 2012
Month: 3
X-DOI: 10.1080/13873954.2012.678859
File-URL: http://hdl.handle.net/10.1080/13873954.2012.678859
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Handle: RePEc:taf:nmcmxx:v:18:y:2012:i:6:p:571-586
Template-Type: ReDIF-Article 1.0
Author-Name: G. Carofiglio
Author-X-Name-First: G.
Author-X-Name-Last: Carofiglio
Author-Name: R. Gaeta
Author-X-Name-First: R.
Author-X-Name-Last: Gaeta
Author-Name: M. Garetto
Author-X-Name-First: M.
Author-X-Name-Last: Garetto
Author-Name: P. Giaccone
Author-X-Name-First: P.
Author-X-Name-Last: Giaccone
Author-Name: E. Leonardi
Author-X-Name-First: E.
Author-X-Name-Last: Leonardi
Author-Name: M. Sereno
Author-X-Name-First: M.
Author-X-Name-Last: Sereno
Title: Fluid-diffusive modelling for large P2P file-sharing systems
Abstract:
This article presents an application of the basic concepts of
statistical physics to devise an approximate model describing the dynamics
of large peer-to-peer (P2P) file-sharing networks, based on
fluid-diffusive equations. The model we propose is quite general and
highly modular and allows to represent several effects related to resource
distribution among peers, user behaviour, resource localization algorithms
and dynamic structure of the overlay topology. As the complexity of the
model is largely independent of the system size, it provides an effective
method for the analysis of very large P2P systems.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 587-612
Issue: 6
Volume: 18
Year: 2012
Month: 3
X-DOI: 10.1080/13873954.2012.689304
File-URL: http://hdl.handle.net/10.1080/13873954.2012.689304
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Handle: RePEc:taf:nmcmxx:v:18:y:2012:i:6:p:587-612
Template-Type: ReDIF-Article 1.0
Author-Name: Ali Chaibakhsh
Author-X-Name-First: Ali
Author-X-Name-Last: Chaibakhsh
Title: Modelling and long-term simulation of a heat recovery steam generator
Abstract:
Developing accurate non-linear dynamical models for heat recovery steam generator (HRSG) units is presented in this article. The common non-linear autoregressive with exogenous input (NARX) system topology was employed to develop the neuro-fuzzy models based on the experimental data taken during field experiments. In this structure, the non-linear behaviours of the HRSG unit can be characterized through interpolation of local linear models associated with different operating regions via fuzzy inference mechanism. The operating regimes were recognized by applying a genetic algorithm-based fuzzy clustering technique to the prepared data sets. The structures of the fuzzy models are defined with respect to the obtained optimal cluster centres and the corresponding membership functions. The parameters of fuzzy rules were adjusted by recursive least-squares estimation method to fit the model responses to real data. The performances of developed models were evaluated by performing a comparison between the model responses and the responses of the real plant. In addition, the stability of the developed models was assessed by perturbing the model inputs from the nominal values. This guarantees the long-term simulation capabilities of the developed models. A comparison between the responses of the corresponding models and the models obtained from some recent modelling approaches was performed to show the advantages of the developed models. The results show the accuracy and reliability of the developed models at transient and steady-state conditions.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 91-114
Issue: 2
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2012.698623
File-URL: http://hdl.handle.net/10.1080/13873954.2012.698623
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:2:p:91-114
Template-Type: ReDIF-Article 1.0
Author-Name: Attila Egedy
Author-X-Name-First: Attila
Author-X-Name-Last: Egedy
Author-Name: Tamás Varga
Author-X-Name-First: Tamás
Author-X-Name-Last: Varga
Author-Name: Tibor Chován
Author-X-Name-First: Tibor
Author-X-Name-Last: Chován
Title: Compartment model structure identification with qualitative methods for a stirred vessel
Abstract:
Solving process design, process optimization, safety analysis and other problems widely relies on mathematical models of the process. To solve problems related to mixing, detailed models such as compartment models or computational fluid dynamics (CFD) models are required. Compartment modelling generally uses four basic compartments: the mixer (M), the distributor (D), the perfectly mixed reactor and the ideal plug flow reactor (PFR). The main modelling tasks using compartment models are defining the structure of the compartment model and determining the parameters of the connections between the compartments. Hence, a qualitative approach was developed to support this identification process. Qualitative methods can be applied to analyse experimental data and to compress the information content of a time series. The primary goal of this study is to present an algorithm based on qualitative analysis that can be used to identify a compartment model structure based on the hydrodynamic measurement data of a stirred reactor.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 115-132
Issue: 2
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2012.700939
File-URL: http://hdl.handle.net/10.1080/13873954.2012.700939
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:2:p:115-132
Template-Type: ReDIF-Article 1.0
Author-Name: Oğuz Durmaz
Author-X-Name-First: Oğuz
Author-X-Name-Last: Durmaz
Author-Name: H. Karaca
Author-X-Name-First: H.
Author-X-Name-Last: Karaca
Author-Name: G. Özen
Author-X-Name-First: G.
Author-X-Name-Last: Özen
Author-Name: Coşku Kasnakoğlu
Author-X-Name-First: Coşku
Author-X-Name-Last: Kasnakoğlu
Author-Name: D. Funda Kurtuluş
Author-X-Name-First: D.
Author-X-Name-Last: Funda Kurtuluş
Title: Dynamical modelling of the flow over a flapping wing using proper orthogonal decomposition and system identification techniques
Abstract:
A systematic approach for the dynamical modelling of the unsteady flow over a flapping wing is developed, which is based on instantaneous velocity field data of the flow collected using particle image velocimetry (PIV) and computational fluid dynamics (CFD) simulations. The location and orientation of the airfoil is obtained by image processing and the airfoil is filled with proper velocity data. Proper orthogonal decomposition (POD) is applied to these post-processed images to compute POD modes and time coefficients, and a discrete-time state-space dynamical model is fit to the trajectories of the time coefficients using subspace system identification (N4SID). The procedure is verified using PIV and CFD data obtained from a pitching NACA0012 airfoil. The simulation results confirm that the dynamical model obtained from the method proposed can represent the flow dynamics with acceptable accuracy.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 133-158
Issue: 2
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2012.705859
File-URL: http://hdl.handle.net/10.1080/13873954.2012.705859
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:2:p:133-158
Template-Type: ReDIF-Article 1.0
Author-Name: Joydev Chattopadhyay
Author-X-Name-First: Joydev
Author-X-Name-Last: Chattopadhyay
Author-Name: Ezio Venturino
Author-X-Name-First: Ezio
Author-X-Name-Last: Venturino
Author-Name: Samrat Chatterjee
Author-X-Name-First: Samrat
Author-X-Name-Last: Chatterjee
Title: Aggregation of toxin-producing phytoplankton acts as a defence mechanism – a model-based study
Abstract:
We propose a simple model of toxin-producing phytoplankton–zooplankton interactions in which the former is assumed to be able to detect the presence of zooplankton and to counteract it by forming patches and by releasing some toxic chemicals in the surrounding water. We observe that the formation of patch by the toxin-producing phytoplankton decreases the grazing pressure of zooplankton, resulting in stronger coupling between the interacting species determined by the fraction of the phytoplankton population that aggregates to form patches. Finally, the results were validated by comparing them with an alternative spatial model.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 159-174
Issue: 2
Volume: 19
Year: 2013
Month: April
X-DOI: 10.1080/13873954.2012.708876
File-URL: http://hdl.handle.net/10.1080/13873954.2012.708876
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:2:p:159-174
Template-Type: ReDIF-Article 1.0
Author-Name: Y. Valeriano-Medina
Author-X-Name-First: Y.
Author-X-Name-Last: Valeriano-Medina
Author-Name: A. Martínez
Author-X-Name-First: A.
Author-X-Name-Last: Martínez
Author-Name: L. Hernández
Author-X-Name-First: L.
Author-X-Name-Last: Hernández
Author-Name: H. Sahli
Author-X-Name-First: H.
Author-X-Name-Last: Sahli
Author-Name: Y. Rodríguez
Author-X-Name-First: Y.
Author-X-Name-Last: Rodríguez
Author-Name: J.R. Cañizares
Author-X-Name-First: J.R.
Author-X-Name-Last: Cañizares
Title: Dynamic model for an autonomous underwater vehicle based on experimental data
Abstract:
The use of Autonomous Underwater Vehicles (AUV) as robots for exploration and oceanology science has been a field of interest of several universities and research centres around the world. Researchers from the Universidad Central de Las Villas (UCLV) and the Hydrographic Research Center (HRC) have joined forces in the development of the HRC–AUV project. This article is aimed at displaying the calculation of the HRC–AUV dynamic model, based on low-cost sensors and a set at low-cost experiments. The model is developed to synthesize control algorithms, fault tolerance schemes and navigation systems. Dynamic behaviour and validation of the obtained model is evaluated by means of simulation and sea trials experimental data. Based on a simplified versions of the dynamic model, a heading and pitch/depth controls were implemented. Experimental results of heading and pitch/depth controls and a basic path following are presented.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 175-200
Issue: 2
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2012.717226
File-URL: http://hdl.handle.net/10.1080/13873954.2012.717226
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:2:p:175-200
Template-Type: ReDIF-Article 1.0
Author-Name: Olusegun J. Ilegbusi
Author-X-Name-First: Olusegun J.
Author-X-Name-Last: Ilegbusi
Author-Name: Behnaz Seyfi
Author-X-Name-First: Behnaz
Author-X-Name-Last: Seyfi
Author-Name: Rafael Salvin
Author-X-Name-First: Rafael
Author-X-Name-Last: Salvin
Title: Patient-specific model of lung deformation using spatially dependent constitutive parameters
Abstract:
Breathing-induced spatially dependent lung deformation is predicted using patient-specific elastic properties with the contact–impact analysis model. The lung geometry is derived from 4D CT scan data of real patients. The spatially varying Young’s modulus for the patient is obtained from a previous study that used inverse deformation of the lung. The compact–impact analysis is implemented using the finite element method. The predicted lung deformation is compared with the results based on linear elasticity. The results are consistent with physiology, indicating large deformations near the diaphragm and smaller values at remote locations on the lobe. The effect of non-linearity of elastic property is most significant at the remote locations where the diaphragm-induced deformation is significantly attenuated.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 546-556
Issue: 6
Volume: 20
Year: 2014
Month: 11
X-DOI: 10.1080/13873954.2013.842927
File-URL: http://hdl.handle.net/10.1080/13873954.2013.842927
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:6:p:546-556
Template-Type: ReDIF-Article 1.0
Author-Name: Roberto Cervelló
Author-X-Name-First: Roberto
Author-X-Name-Last: Cervelló
Author-Name: Juan- C. Cortés
Author-X-Name-First: Juan- C.
Author-X-Name-Last: Cortés
Author-Name: Francisco- J. Santonja
Author-X-Name-First: Francisco- J.
Author-X-Name-Last: Santonja
Author-Name: Rafael- J. Villanueva
Author-X-Name-First: Rafael- J.
Author-X-Name-Last: Villanueva
Title: The dynamics over the next few years of the Spanish mobile telecommunications market share: a mathematical modelling approach
Abstract:
Taking into account available data from 2002 to 2009 about the market share percentages of the Spanish mobile telecommunications service providers, a dynamic diffusion model to study the evolution of the clients’ change between the different companies during the period 2010–2016 is proposed. The constructed model provides a tool for forecasting short-term trends about the customers’ preferences with respect to mobile network operators taking into account both, autonomous decisions due to direct marketing and advertising strategies, and also decisions adopted through interaction via social influence. The model can provide insights to companies for designing strategies in order to gain market share.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 557-565
Issue: 6
Volume: 20
Year: 2014
Month: 11
X-DOI: 10.1080/13873954.2013.843572
File-URL: http://hdl.handle.net/10.1080/13873954.2013.843572
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:6:p:557-565
Template-Type: ReDIF-Article 1.0
Author-Name: Alexandra Mehlhase
Author-X-Name-First: Alexandra
Author-X-Name-Last: Mehlhase
Title: A Python framework to create and simulate models with variable structure in common simulation environments
Abstract:
In modelling and simulation, model complexity increases with the complexity of real systems, often resulting in unfeasibly long simulation times. Variable-structure models, which can change their equation set during run-time, offer a solution. This article introduces an object-oriented approach that describes such models independent of a simulation environment. The problem of changing equations during run-time is addressed using a Python framework. Three tools are already integrated, namely, Dymola, OpenModelica and Matlab/Simulink. With this framework, existing models can be easily reused, and the advantages of different simulation tools can be leveraged. The framework is illustrated using a simple satellite launch example, along with instructions for how to use the framework. The main aim of the framework is to simulate complex models with a few mode changes and thus save simulation time. With two real-world examples and a scalability analysis, it is shown that the framework fulfils these requirements.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 566-583
Issue: 6
Volume: 20
Year: 2014
Month: 11
X-DOI: 10.1080/13873954.2013.861854
File-URL: http://hdl.handle.net/10.1080/13873954.2013.861854
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:6:p:566-583
Template-Type: ReDIF-Article 1.0
Author-Name: W. Borutzky
Author-X-Name-First: W.
Author-X-Name-Last: Borutzky
Title: Bond graph model-based system mode identification and mode-dependent fault thresholds for hybrid systems
Abstract:
Hybrid system models exploit the modelling abstraction that fast state transitions take place instantaneously so that they encompass discrete events and the continuous time behaviour for the while of a system mode. If a system is in a certain mode, e.g. two rigid bodies stick together, then residuals of analytical redundancy relations (ARRs) within certain small bounds indicate that the system is healthy. An unobserved mode change, however, invalidates the current model for the dynamic behaviour. As a result, ARR residuals may exceed current thresholds indicating faults in system components that have not happened. The paper shows that ARR residuals derived from a bond graph cannot only serve as fault indicators but may also be used for bond graph model-based system mode identification. ARR residuals are numerically computed in an off-line simulation by coupling a bond graph of the faulty system to a non-faulty system bond graph through residual sinks. In real-time simulation, the faulty system model is to be replaced by measurements from the real system. As parameter values are uncertain, it is important to determine adaptive ARR thresholds that, given uncertain parameters, allow to decide whether the dynamic behaviour in a current system mode is the one of the healthy system so that false alarms or overlooking of true faults can be avoided. The paper shows how incremental bond graphs can be used to determine adaptive mode-dependent ARR thresholds for switched linear time-invariant systems with uncertain parameters in order to support robust fault detection. Bond graph-based hybrid system mode identification as well as the determination of adaptive fault thresholds is illustrated by application to a power electronic system easy to survey. Some simulation results have been analytically validated.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 584-615
Issue: 6
Volume: 20
Year: 2014
Month: 11
X-DOI: 10.1080/13873954.2013.874361
File-URL: http://hdl.handle.net/10.1080/13873954.2013.874361
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:6:p:584-615
Template-Type: ReDIF-Article 1.0
Author-Name: T. Pumhössel
Author-X-Name-First: T.
Author-X-Name-Last: Pumhössel
Author-Name: P. Hehenberger
Author-X-Name-First: P.
Author-X-Name-Last: Hehenberger
Author-Name: K. Zeman
Author-X-Name-First: K.
Author-X-Name-Last: Zeman
Title: Reduced-order modelling of self-excited, time-periodic systems using the method of Proper Orthogonal Decomposition and the Floquet theory
Abstract:
The mathematical models of dynamical systems become more and more complex, and hence, numerical investigations are a time-consuming process. This is particularly disadvantageous if a repeated evaluation is needed, as is the case in the field of model-based design, for example, where system parameters are subject of variation. Therefore, there exists a necessity for providing compact models which allow for a fast numerical evaluation. Nonetheless, reduced models should reflect at least the principle of system dynamics of the original model.In this contribution, the reduction of dynamical systems with time-periodic coefficients, termed as parametrically excited systems, subjected to self-excitation is addressed. For certain frequencies of the time-periodic coefficients, referred to as parametric antiresonance frequencies, vibration suppression is achieved, as it is known from the literature. It is shown in this article that by using the method of Proper Orthogonal Decomposition (POD) excitation at a parametric antiresonance frequency results in a concentration of the main system dynamics in a subspace of the original solution space. The POD method allows to identify this subspace accurately and to set up reduced models which approximate the stability behaviour of the original model in the vicinity of the antiresonance frequency in a satisfying manner. For the sake of comparison, modally reduced models are established as well.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 528-545
Issue: 6
Volume: 20
Year: 2014
Month: 11
X-DOI: 10.1080/13873954.2014.880181
File-URL: http://hdl.handle.net/10.1080/13873954.2014.880181
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:6:p:528-545
Template-Type: ReDIF-Article 1.0
Author-Name: The Editors
Title: Statement of Retractions
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 616-617
Issue: 6
Volume: 20
Year: 2014
Month: 11
X-DOI: 10.1080/13873954.2014.934128
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:6:p:616-617
Template-Type: ReDIF-Article 1.0
Author-Name: The Editors
Title: Editorial Board
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: ebi-ebi
Issue: 6
Volume: 20
Year: 2014
Month: 11
X-DOI: 10.1080/13873954.2014.949090
File-URL: http://hdl.handle.net/10.1080/13873954.2014.949090
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:6:p:ebi-ebi
Template-Type: ReDIF-Article 1.0
Author-Name: Adnan Khan
Author-X-Name-First: Adnan
Author-X-Name-Last: Khan
Author-Name: Muhammad Waleed
Author-X-Name-First: Muhammad
Author-X-Name-Last: Waleed
Author-Name: Mudassar Imran
Author-X-Name-First: Mudassar
Author-X-Name-Last: Imran
Title: Mathematical analysis of an influenza epidemic model, formulation of different controlling strategies using optimal control and estimation of basic reproduction number
Abstract:
In this article, a deterministic model is formulated to perform a thorough investigation of the transmission dynamics of influenza. In particular, our model takes into account the effects of medication as well as hospitalization. An in-depth stability analysis of the model is performed, and it is subsequently shown that the model is locally, as well as globally asymptotically stable, when R0 > 1. It is also shown that there exists a unique endemic equilibrium whenever R0 > 1. After estimating the effective contact rate, we estimate the basic reproduction number, using both an ordinary least squares and generalized least squares methodology. We also estimated confidence intervals for the effective contact rate using parametric bootstrapping. Furthermore, we perform uncertainty and sensitivity analysis to recognize the impact of crucial model parameters on R0. In addition, using ideas from the optimal control theory, optimal medication and hospitalization strategies are proposed to eliminate the disease.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 432-459
Issue: 5
Volume: 21
Year: 2015
Month: 9
X-DOI: 10.1080/13873954.2015.1016975
File-URL: http://hdl.handle.net/10.1080/13873954.2015.1016975
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:5:p:432-459
Template-Type: ReDIF-Article 1.0
Author-Name: Hana Baili
Author-X-Name-First: Hana
Author-X-Name-Last: Baili
Author-Name: Mohamad Assaad
Author-X-Name-First: Mohamad
Author-X-Name-Last: Assaad
Title: Optimal scheduling and power allocation in wireless networks with heavy traffic
Abstract:
This paper addresses the problem of joint transmit power allocation and time slot scheduling in a wireless communication system with time varying traffic. The system is handled by a single base station transmitting over time varying channels. This may be the case in practice of a hybrid TDMA-CDMA (Time Division Multiple Access-Code Division Multiple Access) system. The operating time horizon is divided into time slots; a fixed amount of power is available at each time slot. The users share each time slot and the power available at this time slot with the objective of minimizing the expected total queue length. The problem is reformulated, via a heavy traffic approximation, as the optimal control of a reflected diffusion in the positive orthant. We establish a closed form solution for the obtained control problem. The main feature that makes it possible is an astute choice of some auxiliary weighting matrices in the cost rate. The proposed solution relies also on the knowledge of the covariance matrix of the non-standard multi-dimensional Wiener process which is the driving process in the reflected diffusion. We then compute this covariance matrix given the stationary distribution of the multi-dimensional channel process. Further stochastic analysis is provided: the cost variance, and the Fokker–Planck equation for the distribution density of the queue length.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 480-508
Issue: 5
Volume: 21
Year: 2015
Month: 9
X-DOI: 10.1080/13873954.2015.1022191
File-URL: http://hdl.handle.net/10.1080/13873954.2015.1022191
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:5:p:480-508
Template-Type: ReDIF-Article 1.0
Author-Name: Noël Bonneuil
Author-X-Name-First: Noël
Author-X-Name-Last: Bonneuil
Title: Emotions as dynamic systems in viability sets
Abstract:
Emotions are viewed as dynamic systems with potentially varied contingent consequences and under viability constraints, responding to the principle of maintenance or acquisition of desired properties. Most emotions are classified by their memberships of viability sets, which in turn conceal the quantifiers ‘there exists’ (‘$$\exists $$∃
’) and ‘for all’ (‘$$\forall $$∀
’). Describing emotions in this way uses most of the concepts of viability theory, because emotions and viability sets both deal with survival and change. Emotion regulation mirrors mathematical controls, which can be operated in various ways, optimally or not, and that allow for improvement by learning. Application is to Maupassant’s A Woman’s Life, with viability kernels and capture basins succeeding each other in a description of the sequence of emotions felt by the heroine, and to a reappraisal of Laura and Petrarch’s emotional cycle.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 460-479
Issue: 5
Volume: 21
Year: 2015
Month: 9
X-DOI: 10.1080/13873954.2014.961487
File-URL: http://hdl.handle.net/10.1080/13873954.2014.961487
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:5:p:460-479
Template-Type: ReDIF-Article 1.0
Author-Name: S. Leitner
Author-X-Name-First: S.
Author-X-Name-Last: Leitner
Author-Name: D.A. Behrens
Author-X-Name-First: D.A.
Author-X-Name-Last: Behrens
Title: On the efficiency of hurdle rate-based coordination mechanisms
Abstract:
Financial resources are scarce, which is why corporate capital budgeting needs to employ efficient allocation mechanisms. This paper conceptually transforms the idea behind a hurdle rate-based coordination mechanism from an agency model into a computational model of a multi-divisional corporation with both heterogeneous departments and heterogeneous investment opportunities competing for the same source of funding. On the basis of our results, we reason that for heterogeneous investment opportunities a recurrent use of a hurdle rate-based coordination mechanism can work efficiently only if intra-organizational communication is assumed to be absent. We show that, if only a single investment opportunity can be carried into execution due to scarce financial resources, the heterogeneity of the competing investment opportunities positively affects the departments’ pay-offs, while the number of proposed investment projects negatively impacts departmental utilities derived from a residual income. The latter is why our results support the assumption that an emergence of cooperation is to be expected as soon as departments can establish interdepartmental communication, rendering a hurdle rate-based coordination mechanism inefficient.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 413-431
Issue: 5
Volume: 21
Year: 2015
Month: 9
X-DOI: 10.1080/13873954.2014.973885
File-URL: http://hdl.handle.net/10.1080/13873954.2014.973885
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:5:p:413-431
Template-Type: ReDIF-Article 1.0
Author-Name: Atiyah Elsheikh
Author-X-Name-First: Atiyah
Author-X-Name-Last: Elsheikh
Author-Name: Wolfgang Wiechert
Author-X-Name-First: Wolfgang
Author-X-Name-Last: Wiechert
Title: The structural index of sensitivity equation systems
Abstract:
This work presents a new methodology for computing parameter sensitivities of differential algebraic system of equations with higher differential index. This methodology is particularly adequate for performing sensitivity analysis of object-oriented models described by modern universal modelling languages. By employing the same concepts and tools adopted by these languages for structural analysis of systems of equations, it is shown that the computational graphs of a differential algebraic system of equations and its corresponding sensitivity equation are structurally isomorphic. As a consequence, the structural index of both systems of equations are proven to be equal. Based on this result, an efficient strategy for index reduction of sensitivity equations is designed.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 573-592
Issue: 6
Volume: 24
Year: 2018
Month: 11
X-DOI: 10.1080/13873954.2018.1531034
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1531034
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:6:p:573-592
Template-Type: ReDIF-Article 1.0
Author-Name: Jozef Vörös
Author-X-Name-First: Jozef
Author-X-Name-Last: Vörös
Title: Modelling and identification of nonlinear cascade systems with backlash input and static output nonlinearities
Abstract:
A new approach to the parameter identification of nonlinear dynamic systems using cascade models with nonlinear dynamic, linear dynamic and nonlinear static blocks is presented. Application of the key-term separation principle provides special expressions for the corresponding nonlinear model description that are linear in parameters. A least-squares-based iterative technique is proposed allowing estimation of all the model parameters based on measured input/output data. Illustrative examples of nonlinear cascade systems identification with input backlash and nonlinear static output characteristics are included.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 593-609
Issue: 6
Volume: 24
Year: 2018
Month: 11
X-DOI: 10.1080/13873954.2018.1521840
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1521840
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:6:p:593-609
Template-Type: ReDIF-Article 1.0
Author-Name: Wei-Gang Wang
Author-X-Name-First: Wei-Gang
Author-X-Name-Last: Wang
Author-Name: Yao-Lin Jiang
Author-X-Name-First: Yao-Lin
Author-X-Name-Last: Jiang
Title: optimal model order reduction on the Stiefel manifold for the MIMO discrete system by the cross Gramian
Abstract:
In this paper, the H2 optimal model order reduction method for the large-scale multiple-input multiple-output (MIMO) discrete system is investigated. First, the MIMO discrete system is resolved into a number of single-input single-output (SISO) subsystems, and the H2 norm of the original MIMO discrete system is expressed by the cross Gramian of each subsystem. Then, the retraction and the vector transport on the Stiefel manifold are introduced, and the geometric conjugate gradient model order reduction method is proposed. The reduced system of the original MIMO discrete system is generated by using the proposed method. Finally, two numerical examples show the efficiency of the proposed method.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 610-625
Issue: 6
Volume: 24
Year: 2018
Month: 11
X-DOI: 10.1080/13873954.2018.1519835
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1519835
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:6:p:610-625
Template-Type: ReDIF-Article 1.0
Author-Name: Jørgen Bremnes Nielsen
Author-X-Name-First: Jørgen Bremnes
Author-X-Name-Last: Nielsen
Author-Name: Eilif Pedersen
Author-X-Name-First: Eilif
Author-X-Name-Last: Pedersen
Title: On the modelling of heat exchangers and heat exchanger network dynamics using bond graphs
Abstract:
Heat exchanger networks are important systems in most thermal engineering systems and are found in applications ranging from power plants and the process industry to domestic heating. Achieving cost-effective design of heat exchanger networks relies heavily on mathematical modelling and simulation-based design. Today, stationary design calculations are carried out for all new designs, but for some special applications, the transient response of complete networks has been researched. However, simulating large heat exchanger networks poses challenges due to computational speed and stiff initial value problems when flow equations are cast in differential algebraic form. In this article, a systems approach to heat exchanger and heat exchanger network modelling is suggested. The modelling approach aims at reducing the cost of system model development by producing modular and interchangeable models. The approach also aims at improving the capability for large and complex network simulation by suggesting an explicit formulation of the network flow problem.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 626-642
Issue: 6
Volume: 24
Year: 2018
Month: 11
X-DOI: 10.1080/13873954.2018.1533566
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1533566
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:6:p:626-642
Template-Type: ReDIF-Article 1.0
Author-Name: Dariusz Szpica
Author-X-Name-First: Dariusz
Author-X-Name-Last: Szpica
Title: Modelling of the operation of a Dual Mass Flywheel (DMF) for different engine-related distortions
Abstract:
The application of Dual Mass Flywheels (DMF) was inspired by the need to reduce the level of vibrations generated by the drivetrain. The DMF input parameters are a result of the engine operation, in which the cyclicity of the subsequent strokes results in a variation of the engine speed. The fewer the cylinders the greater the engine speed variation and fluctuation of the engine torque. Additionally, the engine speed and torque variations are influenced by distortions, which is why the author attempted to develop a mathematical model of a DMF based on the motion equation. The methodology of calculations was also presented. For simplification, the moment of resistance generated by the drivetrain was assumed as constant. The simulation model checked out as correct and its sensitivity to small changes of the input parameters was confirmed. The mathematical description, despite simplifications, may find application in modelling of drivetrains fitted with DMF.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 643-660
Issue: 6
Volume: 24
Year: 2018
Month: 11
X-DOI: 10.1080/13873954.2018.1521839
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1521839
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:6:p:643-660
Template-Type: ReDIF-Article 1.0
Author-Name: Mohammad T. Freigoun
Author-X-Name-First: Mohammad T.
Author-X-Name-Last: Freigoun
Author-Name: Daniel E. Rivera
Author-X-Name-First: Daniel E.
Author-X-Name-Last: Rivera
Author-Name: Penghong Guo
Author-X-Name-First: Penghong
Author-X-Name-Last: Guo
Author-Name: Emily E. Hohman
Author-X-Name-First: Emily E.
Author-X-Name-Last: Hohman
Author-Name: Alison D. Gernand
Author-X-Name-First: Alison D.
Author-X-Name-Last: Gernand
Author-Name: Danielle Symons Downs
Author-X-Name-First: Danielle
Author-X-Name-Last: Symons Downs
Author-Name: Jennifer S. Savage
Author-X-Name-First: Jennifer S.
Author-X-Name-Last: Savage
Title: A dynamical systems model of intrauterine fetal growth
Abstract:
The underlying mechanisms for how maternal perinatal obesity and intrauterine environment influence foetal development are not well understood and thus require further understanding. In this paper, energy balance concepts are used to develop a comprehensive dynamical systems model for foetal growth that illustrates how maternal factors (energy intake and physical activity) influence foetal weight and related components (fat mass, fat-free mass, and placental volume) over time. The model is estimated from intensive measurements of foetal weight and placental volume obtained as part of Healthy Mom Zone (HMZ), a novel intervention for managing gestational weight gain in obese/overweight women. The overall result of the modelling procedure is a parsimonious system of equations that reliably predicts foetal weight gain and birth weight based on a sensible number of assessments. This model can inform clinical care recommendations as well as how adaptive interventions, such as HMZ, can influence foetal growth and birth outcomes.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 661-687
Issue: 6
Volume: 24
Year: 2018
Month: 11
X-DOI: 10.1080/13873954.2018.1524387
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1524387
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:6:p:661-687
Template-Type: ReDIF-Article 1.0
Author-Name: Andreas Klöckner
Author-X-Name-First: Andreas
Author-X-Name-Last: Klöckner
Author-Name: Andreas Knoblach
Author-X-Name-First: Andreas
Author-X-Name-Last: Knoblach
Author-Name: Andreas Heckmann
Author-X-Name-First: Andreas
Author-X-Name-Last: Heckmann
Title: How to shape noise spectra for continuous system simulation
Abstract:
Noise for continuous-time system simulation is relevant for many applications, whenever time domain results are required. Simulating such noise raises the need to consistently shape the frequency content of the signal. However, the methods for this task are not obvious and form filters are often used as approximate state space implementations. In this article, we address the problem with a new method which relies on directly using the specified power spectral density for a convolution filter. For the example of railway track irregularities, we explain how to derive the required filters, implement them in the open-source AdvancedNoise library, and verify the results. The new method produces correct results, is very simple to use, and enables new features for time simulation of physical systems.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 284-300
Issue: 3
Volume: 23
Year: 2017
Month: 5
X-DOI: 10.1080/13873954.2017.1298622
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1298622
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:3:p:284-300
Template-Type: ReDIF-Article 1.0
Author-Name: Alexander Pollok
Author-X-Name-First: Alexander
Author-X-Name-Last: Pollok
Author-Name: Francesco Casella
Author-X-Name-First: Francesco
Author-X-Name-Last: Casella
Title: Modelling and simulation of self-regulating pneumatic valves
Abstract:
In conventional aircraft energy systems, self-regulating pneumatic valves (SRPVs) are used to control the pressure and mass flow of the bleed air. The dynamic behaviour of these valves is complex and dependent on several physical phenomena. In some cases, limit cycles can occur, deteriorating performance. This article presents a complex multi-physical model of SRPVs implemented in Modelica. First, the working principle is explained, and common challenges in control-system design-problems related to these valves are illustrated. Then, a Modelica-model is presented in detail, taking into account several physical domains. It is shown, how limit cycle oscillations occurring in aircraft energy systems can be reproduced with this model. The sensitivity of the model regarding both solver options and physical parameters is investigated.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 243-261
Issue: 3
Volume: 23
Year: 2017
Month: 5
X-DOI: 10.1080/13873954.2017.1298623
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1298623
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:3:p:243-261
Template-Type: ReDIF-Article 1.0
Author-Name: Christian Schallert
Author-X-Name-First: Christian
Author-X-Name-Last: Schallert
Title: Automated safety analysis by minimal path set detection for multi-domain object-oriented models
Abstract:
A method called DMP for Detection of the Minimal Path set of any fault-tolerant technical system, the system being represented as a multi-domain object-oriented model, is described, exemplified and substantiated in this article. Thus, by use of DMP, a safety analysis of the system is automatically performed. DMP employs simulation of normal behaviour, degradation and failure of a system. In essence, it is a state space simulation. The state space, in this context, denotes the set of combinations of intact and failed components of a system to be examined for detection of its minimal path set. Without any reduction technique, the size of a system’s state space grows exponentially with the number of its components. In order to render the DMP method feasible, the object structure of the system model is represented as a graph. Evaluation of the graph reduces the size of the state space and hence the number of simulations required.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 341-360
Issue: 3
Volume: 23
Year: 2017
Month: 5
X-DOI: 10.1080/13873954.2017.1298624
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1298624
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:3:p:341-360
Template-Type: ReDIF-Article 1.0
Author-Name: Christopher R. Laughman
Author-X-Name-First: Christopher R.
Author-X-Name-Last: Laughman
Author-Name: Hongtao Qiao
Author-X-Name-First: Hongtao
Author-X-Name-Last: Qiao
Title: On the influence of state selection on mass conservation in dynamic vapour compression cycle models
Abstract:
Many dynamic models of vapour compression systems experience nonphysical variations in the total refrigerant mass contained in the system when common modelling approaches are used. Rather than using the traditional state variables of pressure and specific enthalpy, the use of density as a state variable can eliminate these variations. The reasons for these variations are explained, and a set of test models is developed to study the effect of the state variable selection on the overall system charge. Results from both a simplified cycle model and a realistic air-source heat pump model indicate that this alternative approach has significant benefits for maintaining a fixed mass of refrigerant in the cycle.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 262-283
Issue: 3
Volume: 23
Year: 2017
Month: 5
X-DOI: 10.1080/13873954.2017.1298625
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1298625
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:3:p:262-283
Template-Type: ReDIF-Article 1.0
Author-Name: Romain Gillot
Author-X-Name-First: Romain
Author-X-Name-Last: Gillot
Author-Name: Mike Dempsey
Author-X-Name-First: Mike
Author-X-Name-Last: Dempsey
Author-Name: Alessandro Picarelli
Author-X-Name-First: Alessandro
Author-X-Name-Last: Picarelli
Title: Predicting the effect of powertrain preconditioning on vehicle efficiency
Abstract:
Under extreme climatic conditions, the vehicle fuel consumption can be far from the certified value. Given the growing concern for polluting emissions, it is necessary to investigate a way to improve the overall vehicle efficiency and thus reduce the emissions and fuel consumption gap. One solution is to pre-warm the gearbox and the engine in order to make it work at an optimal temperature to achieve the best efficiency possible. Indeed, low lubricant temperature is a source of reduced vehicle efficiency due to the lubricant viscosity rising exponentially at very low temperature. Using the Powertrain Dynamics library, a vehicle model with a detailed equation-based gearbox model taking into account the temperature-dependent losses and a map-based engine including temperature-dependent emission models (CO, NOx, HC and particulates) is developed.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 301-318
Issue: 3
Volume: 23
Year: 2017
Month: 5
X-DOI: 10.1080/13873954.2017.1298626
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1298626
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:3:p:301-318
Template-Type: ReDIF-Article 1.0
Author-Name: Matthias J. Reiner
Author-X-Name-First: Matthias J.
Author-X-Name-Last: Reiner
Author-Name: Dirk Zimmer
Author-X-Name-First: Dirk
Author-X-Name-Last: Zimmer
Title: Object-oriented modelling of wind turbines and its application for control design based on nonlinear dynamic inversion
Abstract:
This article presents the object-oriented modelling of wind turbine aero-elastics. The article details the undertaken modelling approach and demonstrates its validity by comparing the results to a domain-specific simulation tool. The resulting object-oriented models can be generically adapted to meet different tasks or combined with models from other domains. Also the combination object-oriented Modelica and functional mock-up interface technology enable a rapid design of nonlinear controllers. As one possible application example, the article presents the model-based design of a corresponding controller. Its goal is to extend the turbine lifetime by reducing the structural loads. To this end, a modern control scheme is proposed that takes full advantage of the underlying object-oriented modelling approach. The controller is based on nonlinear dynamic inversion control methods combined with pseudo control hedging. The controller uses wind speed measurement information to adjust to wind gust load. Simulation-based comparisons to conventional control designs show a large potential reduction of the gust load on the wind turbine using the proposed controller.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 319-340
Issue: 3
Volume: 23
Year: 2017
Month: 5
X-DOI: 10.1080/13873954.2017.1298627
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1298627
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:3:p:319-340
Template-Type: ReDIF-Article 1.0
Author-Name: Gianni Ferretti
Author-X-Name-First: Gianni
Author-X-Name-Last: Ferretti
Author-Name: Peter Fritzson
Author-X-Name-First: Peter
Author-X-Name-Last: Fritzson
Title: Special issue on object-oriented modelling and simulation
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 240-242
Issue: 3
Volume: 23
Year: 2017
Month: 5
X-DOI: 10.1080/13873954.2017.1302965
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1302965
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:3:p:240-242
Template-Type: ReDIF-Article 1.0
Author-Name: The Editors
Title: Corrigendum
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: i-i
Issue: 3
Volume: 23
Year: 2017
Month: 5
X-DOI: 10.1080/13873954.2017.1316022
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1316022
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:3:p:i-i
Template-Type: ReDIF-Article 1.0
Author-Name: Wanyang Dai
Author-X-Name-First: Wanyang
Author-X-Name-Last: Dai
Title: Quantum-computing with AI & blockchain: modelling, fault tolerance and capacity scheduling
Abstract:
We model the hardware and software architecture for generalized Internet of Things (IoT) by quantum cloud-computing and blockchain. To reduce the measurement error and increase the efficiency of quantum entanglement (i.e. the capability of fault tolerance) in the current quantum computers and communications, we design a quantum-computing chip by modelling it as a multi-input multi-output (MIMO) quantum channel and obtain its channel capacity via our recently derived mutual information formula. To capture the internal qubit data flow dynamics of the channel, we model it via a deep convolutional neural network (DCNN) with generalized stochastic pooling in terms of resource-competition among different quantum eigenmodes or users. The pooling is corresponding to a resource allocation policy with two levels of competitions as in cognitive radio: the first one is on users’ selection in a ‘win–lose’ manner; the second one is on resourcesharing among selected users in a ‘win–win’ manner. To wit, our scheduling policy is the one by mixing a saddle point to a zero-sum game problem and a Pareto optimal Nash equilibrium point to a nonzero- sum game problem. The effectiveness of our policy is proved by diffusion modelling with theory and numerical examples.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 523-559
Issue: 6
Volume: 25
Year: 2019
Month: 11
X-DOI: 10.1080/13873954.2019.1677725
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1677725
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:6:p:523-559
Template-Type: ReDIF-Article 1.0
Author-Name: K. Flaßkamp
Author-X-Name-First: K.
Author-X-Name-Last: Flaßkamp
Author-Name: K. Worthmann
Author-X-Name-First: K.
Author-X-Name-Last: Worthmann
Author-Name: J. Mühlenhoff
Author-X-Name-First: J.
Author-X-Name-Last: Mühlenhoff
Author-Name: C. Greiner-Petter
Author-X-Name-First: C.
Author-X-Name-Last: Greiner-Petter
Author-Name: C. Büskens
Author-X-Name-First: C.
Author-X-Name-Last: Büskens
Author-Name: J. Oertel
Author-X-Name-First: J.
Author-X-Name-Last: Oertel
Author-Name: D. Keiner
Author-X-Name-First: D.
Author-X-Name-Last: Keiner
Author-Name: T. Sattel
Author-X-Name-First: T.
Author-X-Name-Last: Sattel
Title: Towards optimal control of concentric tube robots in stereotactic neurosurgery
Abstract:
We consider the design and control problem of concentric tubes used in stereotactic neurosurgery. The goal is to optimally reach a configuration of the cannula linking an entry point on the skullcap to a pre-specified region inside the brain. Key issues related to this task are the mechanical behaviour of the cannula and the topography of the brain. We formulate an optimal control problem in order to determine a feasible path while minimizing brain damage caused by missing follow-the-leader behaviour. Numerical results show the potential of the proposed approach.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 560-574
Issue: 6
Volume: 25
Year: 2019
Month: 11
X-DOI: 10.1080/13873954.2019.1690004
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1690004
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:6:p:560-574
Template-Type: ReDIF-Article 1.0
Author-Name: Puspita Mahata
Author-X-Name-First: Puspita
Author-X-Name-Last: Mahata
Author-Name: Gour Chandra Mahata
Author-X-Name-First: Gour Chandra
Author-X-Name-Last: Mahata
Author-Name: Avik Mukherjee
Author-X-Name-First: Avik
Author-X-Name-Last: Mukherjee
Title: An ordering policy for deteriorating items with price-dependent iso-elastic demand under permissible delay in payments and price inflation
Abstract:
This paper considers the problem of dynamic decision-making for an inventory model for deteriorating items under price inflation and permissible delay in payment. In this paper, we adopt an iso-elastic and selling price dependent demand function to model the finite time horizon inventory for deteriorating items. The stocks deteriorate physically at a constant fraction of the on-hand inventory. The objective of this paper is to determine the optimal retail price, number of replenishments, and the cycle time under two different credit periods so that the net profit is maximized. We discuss the optimization properties and develop an algorithm for solving the problem based on dynamic programming techniques. Numerical examples are presented to illustrate the validity of the optimal control policy, and sensitivity analysis on major parameters is performed to provide more managerial insights into deteriorating items.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 575-601
Issue: 6
Volume: 25
Year: 2019
Month: 11
X-DOI: 10.1080/13873954.2019.1677724
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1677724
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:6:p:575-601
Template-Type: ReDIF-Article 1.0
Author-Name: Rajan Mondal
Author-X-Name-First: Rajan
Author-X-Name-Last: Mondal
Author-Name: Ali Akbar Shaikh
Author-X-Name-First: Ali Akbar
Author-X-Name-Last: Shaikh
Author-Name: Asoke Kumar Bhunia
Author-X-Name-First: Asoke Kumar
Author-X-Name-Last: Bhunia
Title: Crisp and interval inventory models for ameliorating item with Weibull distributed amelioration and deterioration via different variants of quantum behaved particle swarm optimization-based techniques
Abstract:
This paper presents two inventory models for ameliorating items under crisp and interval environments. In these models, three-parameter Weibull distribution is considered to represent both the amelioration and deterioration rates. In crisp, an inventory model is formulated for ameliorating item with fixed values of different inventory parameters. Due to uncertainty, these parameters may not be fixed. In this context, another inventory model with interval valued parameters is developed. Also, demand is dependent on the selling price and advertisement frequency of the product. The corresponding profit maximization problem has been developed. For solving the problem, different variants of quantum behaved particle swarm optimization technique (QPSO) are applied. To validate the proposed models, two numerical examples are considered and solved. The results are compared for different variants of QPSO techniques. Finally, graphical sensitivity analyses are presented to study the impact of several system parameters on cycle length, initial stock level along with average profit for both the models.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 602-626
Issue: 6
Volume: 25
Year: 2019
Month: 11
X-DOI: 10.1080/13873954.2019.1692226
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1692226
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:6:p:602-626
Template-Type: ReDIF-Article 1.0
Author-Name: S.M. Ahmad
Author-X-Name-First: S.M.
Author-X-Name-Last: Ahmad
Title: Flight dynamics, parametric modelling and real-time control of a 1-DOF Tailplane
Abstract:
This article presents aerodynamic modelling and real-time control of a 1-degree-of-freedom free to pitch Tailplane. The system is designed to serve as an experimental test facility for investigating flight dynamics principles, model validation and different feedback control paradigms. A high-fidelity plant model is an important first step in many flight-related applications such as control system design, analyses and pilot training. To achieve these objectives, a detailed study is conducted employing analytical as well as system identification (SI) techniques. Analytical approach although less accurate complements SI process. This synergy is exploited along with statistical and time domain tests to arrive at a high-fidelity model. It is demonstrated that such an integrated approach is suitable for modelling a class of unmanned air vehicles. The SI model is then employed for controller synthesis. Finally, real-time pitch control under stick command is demonstrated utilizing classical proportional integrator control law.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 220-237
Issue: 3
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2012.724427
File-URL: http://hdl.handle.net/10.1080/13873954.2012.724427
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:3:p:220-237
Template-Type: ReDIF-Article 1.0
Author-Name: Mohamad Bakhshali
Author-X-Name-First: Mohamad
Author-X-Name-Last: Bakhshali
Author-Name: Mahsa Mafi
Author-X-Name-First: Mahsa
Author-X-Name-Last: Mafi
Author-Name: Sabalan Daneshvar
Author-X-Name-First: Sabalan
Author-X-Name-Last: Daneshvar
Title: Mathematical modelling of the patent ductus arteriosus (PDA)
Abstract:
The heart is one of the most important and vital body organs, which is responsible for pumping blood to different body tissues. Abnormalities in each part of heart can lead to lack of proper blood circulation. The arterial duct is one of the most important parts of embryonic cycles which may provide the possibility of a relationship between the aorta and the pulmonary artery. The failure of this duct to close after birth causes the abnormality called patent ductus arteriosus (PDA). In this article, we propose a novel model for accurate simulation of PDA abnormality in the human heart. The model is obtained by exploiting the mathematical relation between hemodynamic parameters of heart, including pressure, blood, volume and flow. The proposed model is verified using clinical data.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 238-249
Issue: 3
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2012.727187
File-URL: http://hdl.handle.net/10.1080/13873954.2012.727187
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:3:p:238-249
Template-Type: ReDIF-Article 1.0
Author-Name: M. Hosseinpour
Author-X-Name-First: M.
Author-X-Name-Last: Hosseinpour
Author-Name: P. Nikdel
Author-X-Name-First: P.
Author-X-Name-Last: Nikdel
Author-Name: M.A. Badamchizadeh
Author-X-Name-First: M.A.
Author-X-Name-Last: Badamchizadeh
Author-Name: M.A. Akbari
Author-X-Name-First: M.A.
Author-X-Name-Last: Akbari
Title: Modelling and control of flexible joint robot based on Takagi–Sugeno fuzzy approach and its stability analysis via sum of squares
Abstract:
This article proposes a Takagi–Sugeno (T-S) fuzzy model of single-link rotary flexible joint robot. The proposed control method is based on parallel distributed control. The parameters of T-S controller are improved by distributed population genetic algorithm (GA) with chaos GA. Using Hermite–Biehler theorem in distributed population, GA is made to have a fast convergence. Dividing search space into several sub-spaces causes a better response, and chaos disturbance helps the whole algorithm to reach a best answer. The stability of the controller is analysed via the sum of squares programming, and finally, it is implemented on the plant.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 250-262
Issue: 3
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2012.731653
File-URL: http://hdl.handle.net/10.1080/13873954.2012.731653
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:3:p:250-262
Template-Type: ReDIF-Article 1.0
Author-Name: Adriana Pereira
Author-X-Name-First: Adriana
Author-X-Name-Last: Pereira
Author-Name: Sebastião Gomes
Author-X-Name-First: Sebastião
Author-X-Name-Last: Gomes
Author-Name: Álvaro De Bortoli
Author-X-Name-First: Álvaro
Author-X-Name-Last: De Bortoli
Title: A new formalism for the dynamic modelling of cables
Abstract:
This article proposes a new formalism for the dynamic modelling of cables that can even be applied when they are submitted to cross flow of water or air. An important application is the case of umbilical cables used in remotely operated vehicles. The primary basis for the formulation is to assume that the continuous flexibility is represented by a discrete approach, consisting of rigid links connected by elastic joints, allowing movement in three dimensions. Each elastic joint allows three independent movements, called elevation, azimuth and torsion (twist). A significant contribution of the proposed formalism is the development of a compact equation that allows obtaining the Lagrangian of the system directly and automatically, regardless of the number of links chosen to form a chain of rigid bodies connected by flexible joints to represent the continuous flexibility of the cable. This formulation allows the construction of an algorithm for obtaining the equations of the dynamic model of flexible cables.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 263-276
Issue: 3
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2012.736867
File-URL: http://hdl.handle.net/10.1080/13873954.2012.736867
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:3:p:263-276
Template-Type: ReDIF-Article 1.0
Author-Name: Guido Maione
Author-X-Name-First: Guido
Author-X-Name-Last: Maione
Author-Name: Antonio Punzi
Author-X-Name-First: Antonio
Author-X-Name-Last: Punzi
Title: Combining differential evolution and particle swarm optimization to tune and realize fractional-order controllers
Abstract:
In recent years, several research works proposed fractional-order controllers as means to improve the performances of common proportional, integral and derivative controllers. However, the design and tuning methods for these new controllers are still at their infancy. As a contribute for filling this gap, this article proposes a two-step design approach. First, differential evolution determines the fractional integral and derivative actions satisfying the required time-domain performance specifications. Second, particle swarm optimization determines rational approximations of the irrational fractional operators as low-order, stable, minimum-phase transfer functions with poles interlacing zeros. Extensive time- and frequency-domain simulations validate the efficiency of the proposed approach.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 277-299
Issue: 3
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2012.745006
File-URL: http://hdl.handle.net/10.1080/13873954.2012.745006
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:3:p:277-299
Template-Type: ReDIF-Article 1.0
Author-Name: Trong Phu Do
Author-X-Name-First: Trong Phu
Author-X-Name-Last: Do
Author-Name: Pascal Ziegler
Author-X-Name-First: Pascal
Author-X-Name-Last: Ziegler
Author-Name: Peter Eberhard
Author-X-Name-First: Peter
Author-X-Name-Last: Eberhard
Title: Review on contact simulation of beveloid and cycloid gears and application of a modern approach to treat deformations
Abstract:
Gear drives are key components for all kinds of machines as well as of industrial equipment. Therein, beveloid gears and cycloid gears are increasingly used in industry. Gaining a more comprehensive understanding of those types of gears is essential. However, the measurement of the dynamic response of these gears is not an option due to the high cost of the required experiments. Along with the development of computer technology, several numerical tools and methods to study gears with standard and non-standard flank profiles have been introduced. Various works related to standard gears or beveloid and cycloid gears have been published. In this study, a contemporary review about the modelling and contact simulation of beveloid and cycloid gear drives will be given. Some studies will also be introduced to present an efficient approach to simulate contact forces and contact characteristics of gear wheels with standard and non-standard tooth profiles considering deformations too.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 359-388
Issue: 4
Volume: 21
Year: 2015
Month: 7
X-DOI: 10.1080/13873954.2015.1012838
File-URL: http://hdl.handle.net/10.1080/13873954.2015.1012838
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:4:p:359-388
Template-Type: ReDIF-Article 1.0
Author-Name: Behrooz Mashadi
Author-X-Name-First: Behrooz
Author-X-Name-Last: Mashadi
Author-Name: S.M. Mansourian
Author-X-Name-First: S.M.
Author-X-Name-Last: Mansourian
Author-Name: Amir H. Kakaee
Author-X-Name-First: Amir H.
Author-X-Name-Last: Kakaee
Author-Name: Ali Nassiri Toosi
Author-X-Name-First: Ali Nassiri
Author-X-Name-Last: Toosi
Title: Control of a twin clutch transmission for smooth gearshifts
Abstract:
The flow of torque in a twin clutch transmission is investigated and the different phases of torque transfer between the two clutches are studied. In order to prevent torque backlash and intense wear in dry clutch plates, a proper clamp force regulation is used. A full vehicle simulation that includes vehicle and powertrain components is set up. A Fuzzy logic control system is found suitable for clamp force and engine throttle controls. For upshift and downshift cases, the design of controllers for the gearshift process is carried out by defining proper membership functions and Fuzzy rules using Matlab/SimulinkTM software. The effectiveness of the control system is investigated by simulating two upshift and downshift cases. Results indicate that the control system is successful in regulating the clutch clamp forces and the engine throttle in such a way that a smooth torque flow in the transmission is achieved in all cases.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 389-409
Issue: 4
Volume: 21
Year: 2015
Month: 7
X-DOI: 10.1080/13873954.2015.1033430
File-URL: http://hdl.handle.net/10.1080/13873954.2015.1033430
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:4:p:389-409
Template-Type: ReDIF-Article 1.0
Author-Name: Johannes Henikl
Author-X-Name-First: Johannes
Author-X-Name-Last: Henikl
Title: Corrigendum
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 410-411
Issue: 4
Volume: 21
Year: 2015
Month: 7
X-DOI: 10.1080/13873954.2014.946344
File-URL: http://hdl.handle.net/10.1080/13873954.2014.946344
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:4:p:410-411
Template-Type: ReDIF-Article 1.0
Author-Name: Katharina Prinz
Author-X-Name-First: Katharina
Author-X-Name-Last: Prinz
Author-Name: Wolfgang Kemmetmüller
Author-X-Name-First: Wolfgang
Author-X-Name-Last: Kemmetmüller
Author-Name: Andreas Kugi
Author-X-Name-First: Andreas
Author-X-Name-Last: Kugi
Title: Mathematical modelling of a diesel common-rail system
Abstract:
In diesel common-rail systems, the exact knowledge of the injection pressure is important to accurately control the injected diesel mass and thus the combustion process. This paper focuses on the mathematical modelling of the hydraulic and mechanical components of a common-rail system in order to describe the dynamics of the diesel rail pressure. Based on this model, an average model is derived to reduce the model complexity and to allow for a fast calculation of the mass flow into the rail for different crank shaft revolution speeds and openings of the fuel metering unit. The main purpose of this average model is to serve as a basis for a model-based (non-linear) controller design. The stationary accuracy of the models is validated by means of measurement data.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 311-335
Issue: 4
Volume: 21
Year: 2015
Month: 7
X-DOI: 10.1080/13873954.2014.968590
File-URL: http://hdl.handle.net/10.1080/13873954.2014.968590
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:4:p:311-335
Template-Type: ReDIF-Article 1.0
Author-Name: Fateme Medhat Bojnourd
Author-X-Name-First: Fateme
Author-X-Name-Last: Medhat Bojnourd
Author-Name: Mohammad Ali Fanaei
Author-X-Name-First: Mohammad Ali
Author-X-Name-Last: Fanaei
Author-Name: Hadi Zohreie
Author-X-Name-First: Hadi
Author-X-Name-Last: Zohreie
Title: Mathematical modelling and dynamic simulation of multi-effect falling-film evaporator for milk powder production
Abstract:
Multiple-effect evaporators are widely used in dairies and food industries because they are appropriately suited for concentrating food solutions. Some mathematical models for multi-effect evaporators are reported in previous studies. But most of them are steady-state models, and there are no extensive studies on the dynamic behaviour of these evaporators. In this paper, two types of dynamic model, lumped and distributed, are developed for an industrial four-effect falling-film evaporator which is used to concentrate whole milk. These models are validated with data from an industrial unit. The results show that the distributed model has slightly better predictions than the lumped model, but the lumped model has comparable performance because its structure is simple and the needed simulation time is short in comparison with the distributed model.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 336-358
Issue: 4
Volume: 21
Year: 2015
Month: 7
X-DOI: 10.1080/13873954.2014.980276
File-URL: http://hdl.handle.net/10.1080/13873954.2014.980276
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:4:p:336-358
Template-Type: ReDIF-Article 1.0
Author-Name: Stefan Jakubek
Author-X-Name-First: Stefan
Author-X-Name-Last: Jakubek
Author-Name: Elisabeth Luchini
Author-X-Name-First: Elisabeth
Author-X-Name-Last: Luchini
Author-Name: Alexander Oberhummer
Author-X-Name-First: Alexander
Author-X-Name-Last: Oberhummer
Author-Name: Felix Pfister
Author-X-Name-First: Felix
Author-X-Name-Last: Pfister
Title: A model-based interfacing concept for accurate power hardware-in-the-loop systems
Abstract:
This article introduces a novel concept for the interface of power hardware-in-the-loop (PHiL) test systems. In a PHiL system, a real device under test is connected to dynamic simulation models that emulate high power flows running to and from the device under test. The states of these dynamic models are thus used to physically actuate the real hardware component and likewise the states of the latter serve as an external excitation of the dynamic model. Thus, a PHiL system constitutes a complex interaction of dynamic mathematical models and real hardware components. The purpose of PHiL systems is to operate and test the hardware component as closely to its future designated environment as possible. A crucial factor for a highly accurate PHiL system lies in the interface between virtual dynamic simulation and the physical hardware. Accuracy and performance is often impaired by signal communication delays, sensor noise and insufficient performance of test bed control systems. The approach presented in this article reduces unwanted oscillations based on an online receding optimization of specific state variables in the dynamic simulation environment. In addition, the adherence to physical conservation laws is assured. The interface algorithm makes use of an online model which incorporates knowledge about the dynamics in the underlying simulation. The performance of the proposed methodology is demonstrated and discussed by means of a highly dynamic automotive powertrain PHiL test bed in combination with a complex multibody real-time vehicle simulation.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 1-20
Issue: 1
Volume: 22
Year: 2016
Month: 1
X-DOI: 10.1080/13873954.2015.1069748
File-URL: http://hdl.handle.net/10.1080/13873954.2015.1069748
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:1:p:1-20
Template-Type: ReDIF-Article 1.0
Author-Name: Anders Eriksson
Author-X-Name-First: Anders
Author-X-Name-Last: Eriksson
Author-Name: Hans-Christer Holmberg
Author-X-Name-First: Hans-Christer
Author-X-Name-Last: Holmberg
Author-Name: Håkan Westerblad
Author-X-Name-First: Håkan
Author-X-Name-Last: Westerblad
Title: A numerical model for fatigue effects in whole-body human exercise
Abstract:
A physiology-based fatigue model was developed and tested, with the long-term objective to study optimal pacing strategies in cross-country skiing. The model considers both aerobic and anaerobic power contributions, with different demands for carbohydrate fuel. The fatigue model accumulates traces from anaerobic efforts, and dissipates fatigue exponentially. The current fatigue value affects the effective work rate output. A limited reservoir of fuel is considered. This paper discusses the numerical formulations. Examples show the relevance of the model for basic regimes of power output, and give qualitatively relevant results, but demonstrate the need for individual physiological parameters. Further examples study the model’s predictions with respect to interval training strategies, with conclusions on work rates and interval lengths.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 21-38
Issue: 1
Volume: 22
Year: 2016
Month: 1
X-DOI: 10.1080/13873954.2015.1083592
File-URL: http://hdl.handle.net/10.1080/13873954.2015.1083592
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:1:p:21-38
Template-Type: ReDIF-Article 1.0
Author-Name: Joydeep Banerjee
Author-X-Name-First: Joydeep
Author-X-Name-Last: Banerjee
Author-Name: John McPhee
Author-X-Name-First: John
Author-X-Name-Last: McPhee
Title: System dynamic modelling and simulation of hydrodynamic machines
Abstract:
A graph-theoretic framework for the dynamic simulation of hydrodynamic (both axial and radial flow) machines is presented in this article. The physics based analytical models are developed by considering the dynamics of the hydraulic fluid flow and its interaction with the mechanical components. A linear graph is used to capture the topology of the system and the interconnection of the constituent components. Using the graph-theoretic framework, a dynamic model of an automotive hydrodynamic torque converter is developed to simulate its behaviour under different flow conditions. The ability of the model to capture different features of the torque converter will also be demonstrated by simulation. The simulation results are compared with and validated by experimental results in the literature.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 54-86
Issue: 1
Volume: 22
Year: 2016
Month: 1
X-DOI: 10.1080/13873954.2015.1084518
File-URL: http://hdl.handle.net/10.1080/13873954.2015.1084518
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:1:p:54-86
Template-Type: ReDIF-Article 1.0
Author-Name: Ahmad A. Kardan
Author-X-Name-First: Ahmad A.
Author-X-Name-Last: Kardan
Author-Name: Hamid Sadeghi
Author-X-Name-First: Hamid
Author-X-Name-Last: Sadeghi
Title: An efficacious dynamic mathematical modelling approach for creation of best collaborative groups
Abstract:
In many disciplines, including business, publishing, management, health, sports, arts and education, there is a population of people which should be optimally divided into multiple groups based on certain attributes to collaboratively perform a particular task. The problem becomes more complex when some other requirements are also added. They might be importance degrees of grouping criteria, homogeneity, heterogeneity or a mixture of teams, amount of consideration to the preferences of individuals, variability or invariability of group size, having moderators, aggregation or distribution of persons, overlapping level of teams, and so forth. Several researchers have addressed the problem, but they suffered from failure to satisfy all the requirements and/or developed inexact solutions and/or had very long process times. This work reveals how these problems can be mathematically formulated through a binary integer programming approach to construct an effective model which is solvable by exact methods in an acceptable time. The suggested model was validated through data obtained from collaboration of a set of learners in an online learning discussion forum grouped by means of the provided method. The achieved outcomes confirmed that the new approach is satisfactory and promising.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 39-53
Issue: 1
Volume: 22
Year: 2016
Month: 1
X-DOI: 10.1080/13873954.2015.1086382
File-URL: http://hdl.handle.net/10.1080/13873954.2015.1086382
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:1:p:39-53
Template-Type: ReDIF-Article 1.0
Author-Name: Yandong Wang
Author-X-Name-First: Yandong
Author-X-Name-Last: Wang
Author-Name: Guohua Cao
Author-X-Name-First: Guohua
Author-X-Name-Last: Cao
Author-Name: Naige Wang
Author-X-Name-First: Naige
Author-X-Name-Last: Wang
Author-Name: Weihong Peng
Author-X-Name-First: Weihong
Author-X-Name-Last: Peng
Title: Dynamic responses of cable-driven parallel sinking platform
Abstract:
The dynamic responses of cable-driven parallel sinking platform are investigated considering the longitudinal–torsional coupled characteristics of the cable. The dynamic equations of the system are derived through the Lagrange equations, and the geometric matching conditions and the constraint forces at the interfaces between the cables and the platform have also been considered in the equations through Lagrangian multipliers. By neglecting the slack state of the cable, the numerical results of the mathematical model are obtained through Newmark-beta method after transforming the derived differential algebraic equations (DAEs) to a system of ordinary differential equations (ODEs). An ADAMS simulation is carried out, and the ADAMS simulation results agree well with the results obtained through Newmark-beta method. The results have shown that the lateral characteristics of the cables have a great effect on the torsional vibration of the platform, and by arranging the cables correctly will help to reduce the rotation of the platform.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 104-115
Issue: 2
Volume: 23
Year: 2017
Month: 3
X-DOI: 10.1080/13873954.2016.1231119
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1231119
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:2:p:104-115
Template-Type: ReDIF-Article 1.0
Author-Name: M. Bicher
Author-X-Name-First: M.
Author-X-Name-Last: Bicher
Author-Name: N. Popper
Author-X-Name-First: N.
Author-X-Name-Last: Popper
Author-Name: G. Schneckenreither
Author-X-Name-First: G.
Author-X-Name-Last: Schneckenreither
Title: Comparison of a microscopic and a macroscopic age-dependent SIR model
Abstract:
In this work, we compare two structurally different modelling approaches for the simulation of an age-dependent SIR (susceptible, infected, recovered)-type epidemic spread: a microscopic agent-based model and a macroscopic integro-partial differential equation model. Doing so, we put a newly derived mean-field theorem for mixed state-spaces (continuous and discrete) to the test, analytically proving the asymptotic equivalence of the results of both simulations on the aggregate level. Afterwards, both models are executed and compared for abstract scenarios to affirm the derived equivalence. As both models are hereby proven to deliver (asymptotically) the same results, they can be used to supplement each other in terms of structural knowledge of the model, identification and determination of parameters and their values, as well as finally verification and validation.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 177-195
Issue: 2
Volume: 23
Year: 2017
Month: 3
X-DOI: 10.1080/13873954.2016.1232279
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1232279
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:2:p:177-195
Template-Type: ReDIF-Article 1.0
Author-Name: Robert Baždarić
Author-X-Name-First: Robert
Author-X-Name-Last: Baždarić
Author-Name: Drago Matko
Author-X-Name-First: Drago
Author-X-Name-Last: Matko
Author-Name: Aleš Leban
Author-X-Name-First: Aleš
Author-X-Name-Last: Leban
Author-Name: Danjel Vončina
Author-X-Name-First: Danjel
Author-X-Name-Last: Vončina
Author-Name: Igor Škrjanc
Author-X-Name-First: Igor
Author-X-Name-Last: Škrjanc
Title: Fuzzy model predictive control of a DC-DC boost converter based on non-linear model identification
Abstract:
We present a novel method for the fuzzy control of a DC-DC boost converter based on a new approach to modelling the converter using Takagi–Sugeno (T-S) fuzzy identification. Two grades of identification result in a global model of a non-linear dynamical system and its finite impulse response model (FIRM) expression, which is therefore applicable in various model predictive control (MPC) standard methods with constraints. The successful simulation and experimental results shown in this study indicate the robustness and demonstrate stable operation of the DC-DC converter, even in the dynamic exchange of the discontinuous conduction mode (DCM) and the continuous conduction mode (CCM) with the preservation of a similar transient time. Although the study was primarily conducted on a hybrid simulation model of the DC-DC boost converter, the presented method is insensitive to the complexity of the physical process, as it suggests identified model-based control and emphasizes a new, general approach to pulse energy converter (PEC) controls. The statement is pursued with the subsequent application to the physical system of the converter. Furthermore, it underlines the method’s consideration of real-time processing and its final online simplicity.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 116-134
Issue: 2
Volume: 23
Year: 2017
Month: 3
X-DOI: 10.1080/13873954.2016.1232283
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1232283
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:2:p:116-134
Template-Type: ReDIF-Article 1.0
Author-Name: N. Ha Hoang
Author-X-Name-First: N. Ha
Author-X-Name-Last: Hoang
Author-Name: Denis Dochain
Author-X-Name-First: Denis
Author-X-Name-Last: Dochain
Author-Name: Françoise Couenne
Author-X-Name-First: Françoise
Author-X-Name-Last: Couenne
Author-Name: Yann Le Gorrec
Author-X-Name-First: Yann
Author-X-Name-Last: Le Gorrec
Title: Dissipative pseudo-Hamiltonian realization of chemical systems using irreversible thermodynamics
Abstract:
As motivated by the use of physical variables as Hamiltonian storage functions, this article focuses on dissipative pseudo-Hamiltonian realizations of chemical reaction systems, but with a particular emphasis on the continuous stirred tank reactor (CSTR) in order to further explore the structural differences. More precisely, two different dissipative pseudo-Hamiltonian representations are proposed to a given non-isothermal CSTR dynamics thanks to a unified potential function that verifies a thermodynamic evolution criterion. The first one with the singularity of the structure matrix F (where $$F = J - R$$F=J−R
) resulting from thermodynamically inherent properties of the process, is obtained on the basis of functional separability. Even though the amount of dissipation is explicitly derived and exactly exhibits the process irreversibility, the main disadvantage of such a result is that the derivation of alternative pseudo-Hamiltonian models is impossible. One way to circumvent this inherent difficulty is to consider the Brayton–Moser form of the original dynamics. On this basis, a solution required for the Brayton–Moser formulation is first proposed. Interestingly, the proposed solution is based on thermodynamic information only.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 135-155
Issue: 2
Volume: 23
Year: 2017
Month: 3
X-DOI: 10.1080/13873954.2016.1237973
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1237973
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:2:p:135-155
Template-Type: ReDIF-Article 1.0
Author-Name: Salvador Juárez-López
Author-X-Name-First: Salvador
Author-X-Name-Last: Juárez-López
Author-Name: Oscar Camacho
Author-X-Name-First: Oscar
Author-X-Name-Last: Camacho
Author-Name: Isaac Chairez
Author-X-Name-First: Isaac
Author-X-Name-Last: Chairez
Title: Super-twisting-based continuous neural networks modelling of second-order interconnected systems
Abstract:
The aim of this work was to design a non-parametric model of interconnected systems represented by uncertain second-order systems with incomplete information (only the generalized position vector is measurable). Artificial neural networks appeared to be a plausible alternative to get a non-parametric representation of the aforementioned interconnected systems. The modelling strategy used a set of spatial distributed second-order continuous neural networks (CNN). Each node in the interconnected system was represented as a second-order continuous neural network added by the super-twisting discontinuous sliding mode algorithm. The non-parametric modelling problem was reduced to design a feasible expression for the CNN weights in order to reproduce the states (including the generalized derivative of position vector) of all the nodes dynamics together and simultaneously. The adaptive laws for the CNN weights ensured the convergence of the CNN trajectories to the states of the uncertain interconnected system. To investigate the qualitative behaviour of the suggested methodology, two numerical examples were proposed. The first one represents the interconnection of three mass–spring–damper mechanical systems. The second example considers the problem of the non-parametric modelling problem for a wave partial differential equation. A set of three-dimensional graphic representations were used to demonstrate the identification abilities achieved by the CNN designed in this study for the second case.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 156-176
Issue: 2
Volume: 23
Year: 2017
Month: 3
X-DOI: 10.1080/13873954.2016.1238395
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1238395
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:2:p:156-176
Template-Type: ReDIF-Article 1.0
Author-Name: Ling Li
Author-X-Name-First: Ling
Author-X-Name-Last: Li
Author-Name: Min Liu
Author-X-Name-First: Min
Author-X-Name-Last: Liu
Author-Name: Weiming Shen
Author-X-Name-First: Weiming
Author-X-Name-Last: Shen
Author-Name: Guoqing Cheng
Author-X-Name-First: Guoqing
Author-X-Name-Last: Cheng
Title: A dynamic spare parts ordering and pricing policy based on stochastic programming with multi-choice parameters
Abstract:
This paper studies the uncertain and random factors in real-life spare parts supply networks which are abstract and complex dynamical systems, then quantifies these factors in a mathematical model. To seek a dynamic spare parts ordering and pricing policy from a distributor’s viewpoint, stochastic programming with multi-choice parameters is applied to formulate this objective optimization problem. In our model, the optimal objective is to maximize the total expected profit of the members of the spare parts supply network, and the decision variables are distributor’s selling price and ordering quantity in different periods. By using the methods of expectation operator of the fuzzy variable, Lagrange interpolating polynomial and global criteria, the model is solved, and the optimal ordering and pricing policy is obtained. The results of the numerical example and contrast experiments validate the feasibility and efficiency of the proposed model. Some significant conclusions drawn from the results of parameter sensitivity analysis can be referred by management practitioners. This general model can be applied in other fields of supply chain management, where random and uncertain factors need to be considered.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 196-221
Issue: 2
Volume: 23
Year: 2017
Month: 3
X-DOI: 10.1080/13873954.2016.1242140
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1242140
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:2:p:196-221
Template-Type: ReDIF-Article 1.0
Author-Name: Asma Atitallah
Author-X-Name-First: Asma
Author-X-Name-Last: Atitallah
Author-Name: Saïda Bedoui
Author-X-Name-First: Saïda
Author-X-Name-Last: Bedoui
Author-Name: Kamel Abderrahim
Author-X-Name-First: Kamel
Author-X-Name-Last: Abderrahim
Title: Multistage for identification of Wiener time delay systems based on hierarchical gradient approach
Abstract:
This paper deals with the problem of identification of Wiener systems with unknown integer time delay. This problem presents several difficulties, since it consists in estimating simultaneously the integer time delay, the parameters of the linear dynamic subsystem and the parameters of the non-linear static block. To overcome these difficulties, we propose a new approach to identify the Wiener time delay systems based on the Hierarchical gradient identification principle. This proposed method consists, first, in decoupling the original optimization problem into three simple separate criteria jointly optimized and second, in using the gradient algorithm to minimize each function. The analysis gives us insight into the properties of this algorithm and develops condition that must be satisfied to ensure the convergence and to guarantee the use of rounding property. Simulation results are presented to illustrate the performance of the proposed method.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 222-239
Issue: 2
Volume: 23
Year: 2017
Month: 3
X-DOI: 10.1080/13873954.2016.1242143
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1242143
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:2:p:222-239
Template-Type: ReDIF-Article 1.0
Author-Name: Yousef Al-Sweiti
Author-X-Name-First: Yousef
Author-X-Name-Last: Al-Sweiti
Author-Name: Dirk Söffker
Author-X-Name-First: Dirk
Author-X-Name-Last: Söffker
Title: RETRACTED ARTICLE: Cargo pendulation suppression of ship cranes with elastic booms
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 503-529
Issue: 6
Volume: 13
Year: 2007
X-DOI: 10.1080/13873950701214424
File-URL: http://hdl.handle.net/10.1080/13873950701214424
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:6:p:503-529
Template-Type: ReDIF-Article 1.0
Author-Name: Mebarek Hocine
Author-X-Name-First: Mebarek
Author-X-Name-Last: Hocine
Author-Name: Bachir Bel Abbes
Author-X-Name-First: Bachir
Author-X-Name-Last: Bel Abbes
Author-Name: Hadjoui Abdelhamid
Author-X-Name-First: Hadjoui
Author-X-Name-Last: Abdelhamid
Title: Finite element for free vibration analysis of the orthotropic triangular and rectangular plates
Abstract: The hp-version of the finite element method based on a triangular p-element is applied to free vibration of the orthotropic triangular and rectangular plates. The element's hierarchical shape functions, expressed in terms of shifted Legendre orthogonal polynomials, is developed for orthotropic plate analysis by taking into account shear deformation, rotary inertia, and other kinematics effects. Numerical results of frequency calculations are found for the free vibration of the orthotropic triangular and rectangular plates with the effect of the fiber orientation and plate boundary conditions. The results are very well compared to those presented in the literature.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 573-597
Issue: 6
Volume: 13
Year: 2007
X-DOI: 10.1080/13873950701374905
File-URL: http://hdl.handle.net/10.1080/13873950701374905
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:6:p:573-597
Template-Type: ReDIF-Article 1.0
Author-Name: M. Prochaska
Author-X-Name-First: M.
Author-X-Name-Last: Prochaska
Author-Name: F. Probst
Author-X-Name-First: F.
Author-X-Name-Last: Probst
Author-Name: W. Mathis
Author-X-Name-First: W.
Author-X-Name-Last: Mathis
Title: Analysis of emitter-coupled multivibrators by singularly perturbed systems
Abstract: Emitter-coupled multivibrators play a decisive role in electrical engineering, especially for phase locked loops which are key-building blocks of analogue RF front-ends. Since multivibrators correspond to relaxation oscillators, in the following the modelling and analysis by the theory of singularly perturbed systems is presented. Models for fast and slow phenomena are derived, and the fast transients of emitter-coupled multivibrators are analysed for the first time. The results of our analysis lead to significant advantages for the design of electrical multivibrators.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 531-543
Issue: 6
Volume: 13
Year: 2007
X-DOI: 10.1080/13873950701379888
File-URL: http://hdl.handle.net/10.1080/13873950701379888
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:6:p:531-543
Template-Type: ReDIF-Article 1.0
Author-Name: Yingzhe Li
Author-X-Name-First: Yingzhe
Author-X-Name-Last: Li
Author-Name: Zhongqin Lin
Author-X-Name-First: Zhongqin
Author-X-Name-Last: Lin
Author-Name: Hao Wang
Author-X-Name-First: Hao
Author-X-Name-Last: Wang
Author-Name: Yong Chen
Author-X-Name-First: Yong
Author-X-Name-Last: Chen
Title: An automated modelling approach for dynamic performance evaluation of mechatronic multibody systems
Abstract: An automated modelling approach of mechatronic multibody systems is presented in this paper. The proposed approach uses some object-oriented GUI modules to automatically generate the dynamic equations for different domains, solve them with numerical methods to obtain approximate solutions, and then evaluate the dynamic performances of the systems. By systematically defining an elementary linear graph and its general rules, the modules of mechanical parts and kinematic pairs can be modelled independently of special systems by the extensible elementary linear graph (EELG) method, and the member's dynamic equations can be derived by topology matrices operation. Some major advantages of this procedure are as follows: the combinations of mechanical components could be dealt with as an integrated member and directly assembled with other modules, the topology structure of individual members are described by elementary cutset and circuit matrices derived from the elementary linear graph, rotation vector is used to express angular variables for analysing rotation and translation with same linear graph; the function vertices, opening edges, and self-closed edges are first introduced to elementary linear graph of kinematic pairs modelling, multiport for special mechanical members and different ports for various energy domains are defined, and relation equations linking the ports are given for interdisciplinary domains, so that the modules could have the characteristics of reapplication and extensibility. For two typical cases, the approach carried out on a Modelica/Dymola software platform is proved feasible by comparing the results using the EELG method with those of the conventional approach.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 545-572
Issue: 6
Volume: 13
Year: 2007
X-DOI: 10.1080/13873950701381728
File-URL: http://hdl.handle.net/10.1080/13873950701381728
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Handle: RePEc:taf:nmcmxx:v:13:y:2007:i:6:p:545-572
Template-Type: ReDIF-Article 1.0
Author-Name: Hanif Heidari
Author-X-Name-First: Hanif
Author-X-Name-Last: Heidari
Author-Name: H. Zwart
Author-X-Name-First: H.
Author-X-Name-Last: Zwart
Title: Port-Hamiltonian modelling of nonlocal longitudinal vibrations in a viscoelastic nanorod
Abstract:
Analysis of nonlocal axial vibration in a nanorod is a crucial subject in science and engineering because of its wide applications in nanoelectromechanical systems. The aim of this paper is to show how these vibrations can be modelled within the framework of port-Hamiltonian systems. It turns out that two port-Hamiltonian descriptions in physical variables are possible. The first one is in descriptor form, whereas the second one has a non-local Hamiltonian density. In addition, it is shown that under appropriate boundary conditions these models possess a unique solution which is non-increasing in the corresponding ‘energy’, i.e., the associated infinitesimal generator generates a contraction semigroup on a Hilbert space, whose norm is directly linked to the Hamiltonian.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 447-462
Issue: 5
Volume: 25
Year: 2019
Month: 9
X-DOI: 10.1080/13873954.2019.1659374
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1659374
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:5:p:447-462
Template-Type: ReDIF-Article 1.0
Author-Name: Dong-Yuh Yang
Author-X-Name-First: Dong-Yuh
Author-X-Name-Last: Yang
Author-Name: Chia-Huang Wu
Author-X-Name-First: Chia-Huang
Author-X-Name-Last: Wu
Title: Performance analysis and optimization of a retrial queue with working vacations and starting failures
Abstract:
This paper presents a steady-state analysis of an M/M/1 retrial queue with working vacations, in which the server is subject to starting failures. The proposed queueing model is described in terms of the quasi-birth-death (QBD) process. We first derive the system stability condition. We then use the matrix-geometric method to compute the stationary probability distribution of the orbit size. Some performance measures for the system are developed. We construct a cost model, and our objective is to determine the optimal service rates during normal and vacation periods that minimize the expected cost per unit time. The canonical particle swarm optimization (CPSO) algorithm is employed to deal with the cost optimization problem. Numerical results are provided to illustrate the effects of system parameters on the performance measures and the optimal service rates. These results depict the system behaviour and show how the CPSO algorithm can be used to find numerical solutions for optimal service rates.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 463-481
Issue: 5
Volume: 25
Year: 2019
Month: 9
X-DOI: 10.1080/13873954.2019.1660378
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1660378
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:5:p:463-481
Template-Type: ReDIF-Article 1.0
Author-Name: Maria Letizia Bertotti
Author-X-Name-First: Maria Letizia
Author-X-Name-Last: Bertotti
Author-Name: Giovanni Modanese
Author-X-Name-First: Giovanni
Author-X-Name-Last: Modanese
Title: On the evaluation of the takeoff time and of the peak time for innovation diffusion on assortative networks
Abstract:
This paper deals with a generalization of the Bass model for the description of the diffusion of innovations. The generalization keeps into account heterogeneity of the interactions of the consumers and is expressed by a system of several nonlinear differential equations on complex networks. The following contributions can be singled out: first, explicit algorithms are provided for the construction of various families of assortative scale-free networks; second, a method is provided for the identification of the takeoff time and of the peak time, which represent important turning points in the life cycle of an innovation/product; third, the emergence of specific patterns in connection with networks of the same family is observed, whose tentative interpretation is then given. Also, a comparison with an alternative approach is given, within which adoption times of different communities are evaluated of a network describing firm cooperations in South Tyrol.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 482-498
Issue: 5
Volume: 25
Year: 2019
Month: 9
X-DOI: 10.1080/13873954.2019.1660997
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1660997
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:5:p:482-498
Template-Type: ReDIF-Article 1.0
Author-Name: Sajjad Aslani Khiavi
Author-X-Name-First: Sajjad
Author-X-Name-Last: Aslani Khiavi
Author-Name: Hamid Khaloozadeh
Author-X-Name-First: Hamid
Author-X-Name-Last: Khaloozadeh
Author-Name: Fahimeh Soltanian
Author-X-Name-First: Fahimeh
Author-X-Name-Last: Soltanian
Title: Nonlinear modeling and performance analysis of a closed-loop supply chain in the presence of stochastic noise
Abstract:
We study four-echelon supply chains consisting of manufacturer, wholesaler, retailer and customer with recovery center as hybrid recycling channels. In order to gain a larger market share, the retailer often takes the sales as a decision-making variable. For this purpose, in this supply chain, the retailer limits the forecast of market demand in future periods with expected logic. It also manages demand by leveraging prices and choosing market. In this paper, first, we investigate the state-space model of this supply chain system and examine the effect of complex dynamic and stochastic noise on the bullwhip effect. We analytically prove that this factor leads to the bullwhip effect. So, first, we filtered the information between nodes with extended Kalman filter after which we regulated the destructive effects of the bullwhip phenomenon by designing a non-linear quadratic Gaussian optimal controller. Eventually, the simulation results indicate the efficiency of the proposed method.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 499-521
Issue: 5
Volume: 25
Year: 2019
Month: 9
X-DOI: 10.1080/13873954.2019.1663876
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1663876
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:5:p:499-521
Template-Type: ReDIF-Article 1.0
Author-Name: Ngoc Minh Trang Vu
Author-X-Name-First: Ngoc Minh Trang
Author-X-Name-Last: Vu
Author-Name: Laurent Lefèvre
Author-X-Name-First: Laurent
Author-X-Name-Last: Lefèvre
Author-Name: Rémy Nouailletas
Author-X-Name-First: Rémy
Author-X-Name-Last: Nouailletas
Title: Distributed and backstepping boundary controls for port-Hamiltonian systems with symmetries
Abstract:
A geometric spatial reduction for the port-Hamiltonian models is presented in this paper. It is based on the projection which makes use of the symmetries and on the preservation of the ‘natural’ power pairing for the considered system. Thanks to this reduction, an Interconnection and Damping Assignment Passivity Based Control (IDA-PBC-like) synthesis for infinite dimensional port-Hamiltonian systems is investigated. As for the finite dimensional case, a feedback control transforms the original model into a closed-loop target Hamiltonian model. Both distributed control and boundary control are used. The finite rank distributed control is determined to solve an average IDA-PBC matching equation. A backstepping boundary control is used to stabilize the matching error. The control model chosen to illustrate the approach is the so-called resistive diffusion equation for the radial diffusion of the poloidal magnetic flux.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 55-76
Issue: 1
Volume: 23
Year: 2017
Month: 1
X-DOI: 10.1080/13873954.2016.1232280
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1232280
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:1:p:55-76
Template-Type: ReDIF-Article 1.0
Author-Name: Yu. Vetyukov
Author-X-Name-First: Yu.
Author-X-Name-Last: Vetyukov
Author-Name: E. Oborin
Author-X-Name-First: E.
Author-X-Name-Last: Oborin
Author-Name: M. Krommer
Author-X-Name-First: M.
Author-X-Name-Last: Krommer
Author-Name: V. Eliseev
Author-X-Name-First: V.
Author-X-Name-Last: Eliseev
Title: Transient modelling of flexible belt drive dynamics using the equations of a deformable string with discontinuities
Abstract:
Dynamics of a belt drive is analysed using a non-linear model of an extensible string at contour motion, in which the trajectories of particles of the belt are predetermined. The equations of string dynamics at the tight and slack spans are considered in a fixed domain by transforming into a spatial frame. Assuming the absence of slip of the belt on the surface of the pulleys, we arrive at a new model with a discontinuous velocity field and concentrated contact forces. Finite difference discretization allows numerical analysis of the resulting system of partial differential equations with delays. Example solution for the acceleration of a belt drive and an investigation of its frequency response depending on the velocity are presented and discussed.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 40-54
Issue: 1
Volume: 23
Year: 2017
Month: 1
X-DOI: 10.1080/13873954.2016.1232281
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1232281
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:1:p:40-54
Template-Type: ReDIF-Article 1.0
Author-Name: Alessandro Macchelli
Author-X-Name-First: Alessandro
Author-X-Name-Last: Macchelli
Author-Name: Yann Le Gorrec
Author-X-Name-First: Yann
Author-X-Name-Last: Le Gorrec
Author-Name: Héctor Ramírez
Author-X-Name-First: Héctor
Author-X-Name-Last: Ramírez
Title: Boundary energy-shaping control of an isothermal tubular reactor
Abstract:
This paper illustrates a general synthesis methodology of asymptotic stabilizing, energy-based, boundary control laws that are applicable to a large class of distributed port-Hamiltonian systems. The methodological results are applied on a simplified model of an isothermal tubular reactor. Due to the presence of diffusion and convection, such example, even if relatively easy from a computational point of view, is not trivial. The idea here is to design a state feedback law able to perform the energy-shaping task, i.e. able to render the closed-loop system a port-Hamiltonian system with the same structure, but characterized by a new Hamiltonian with a unique and isolated minimum at the equilibrium. Asymptotic stability is then obtained via damping injection on the boundary and is a consequence of the LaSalle’s Invariance Principle in infinite dimensions.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 77-88
Issue: 1
Volume: 23
Year: 2017
Month: 1
X-DOI: 10.1080/13873954.2016.1232282
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1232282
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:1:p:77-88
Template-Type: ReDIF-Article 1.0
Author-Name: Markus Schöberl
Author-X-Name-First: Markus
Author-X-Name-Last: Schöberl
Author-Name: Kurt Schlacher
Author-X-Name-First: Kurt
Author-X-Name-Last: Schlacher
Title: Distributed parameter systems - new methods for modelling and control
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 1-2
Issue: 1
Volume: 23
Year: 2017
Month: 1
X-DOI: 10.1080/13873954.2016.1232291
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1232291
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:1:p:1-2
Template-Type: ReDIF-Article 1.0
Author-Name: Markus Schöberl
Author-X-Name-First: Markus
Author-X-Name-Last: Schöberl
Author-Name: Kurt Schlacher
Author-X-Name-First: Kurt
Author-X-Name-Last: Schlacher
Title: Lagrangian and Hamiltonian formulation for infinite-dimensional systems – a variational point of view
Abstract:
In this article we use the Lagrange multiplier method, which is well-known in constrained optimization theory, to derive several different Hamiltonian counterparts to Lagrangian systems described by partial differential equations in a variational setting. The main observation is the fact that unconstrained, infinite-dimensional systems can be formulated as constrained variational problems, where the constraints are used to hide some or all derivative variables appearing in the Lagrangian. Depending on the chosen derivative variables that are affected by this approach, different representations of the same dynamical system can be achieved. These theoretical investigations will be applied to a demonstrative example from mechanics.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 89-103
Issue: 1
Volume: 23
Year: 2017
Month: 1
X-DOI: 10.1080/13873954.2016.1237968
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1237968
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:1:p:89-103
Template-Type: ReDIF-Article 1.0
Author-Name: Lukas Jadachowski
Author-X-Name-First: Lukas
Author-X-Name-Last: Jadachowski
Author-Name: Andreas Steinboeck
Author-X-Name-First: Andreas
Author-X-Name-Last: Steinboeck
Author-Name: Andreas Kugi
Author-X-Name-First: Andreas
Author-X-Name-Last: Kugi
Title: Two-dimensional thermal modelling with specular reflections in an experimental annealing furnace
Abstract:
A distributed-parameter model of the temperature in an experimental annealing device is developed. In particular, the two-dimensional spatial-temporal temperature evolution in a thin steel strip along its length and width is modelled during the heat-up process assuming temperature uniformity along the thickness. The model captures heat flows caused by thermal radiation in the considered partially specular enclosure, thermal conduction, internal forced convection, boundary heat flows, and in-domain heat sinks. Parameter identification is carried out based on the step response of the system measured by thermocouples and a temporarily installed infrared camera. For model verification, the simulated evolution of the temperature field in the specimen is compared with measurements. The relative accuracy of the proposed model is better than 4.4% of the maximum measured temperature.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 23-39
Issue: 1
Volume: 23
Year: 2017
Month: 1
X-DOI: 10.1080/13873954.2016.1237969
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1237969
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:1:p:23-39
Template-Type: ReDIF-Article 1.0
Author-Name: W. Zhou
Author-X-Name-First: W.
Author-X-Name-Last: Zhou
Author-Name: B. Hamroun
Author-X-Name-First: B.
Author-X-Name-Last: Hamroun
Author-Name: F. Couenne
Author-X-Name-First: F.
Author-X-Name-Last: Couenne
Author-Name: Y. Le Gorrec
Author-X-Name-First: Y.
Author-X-Name-Last: Le Gorrec
Title: Distributed port-Hamiltonian modelling for irreversible processes
Abstract:
Infinite-dimensional port-Hamiltonian representation of irreversible processes accounting for the thermal energy domain is presented. Two examples are studied: the transmission line and a non-isothermal reaction diffusion process. The proposed approach uses thermodynamic variables in order to define the infinite-dimensional interconnection structure linking the different phenomena. A presentation is given for one-dimensional spatial domain. For the transmission line, the Hamiltonian is the total energy and for the reaction diffusion process it is the enthalpy or the opposite of entropy.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 3-22
Issue: 1
Volume: 23
Year: 2017
Month: 1
X-DOI: 10.1080/13873954.2016.1237970
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1237970
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:1:p:3-22
Template-Type: ReDIF-Article 1.0
Author-Name: D. Lebiedz
Author-X-Name-First: D.
Author-X-Name-Last: Lebiedz
Author-Name: J. Unger
Author-X-Name-First: J.
Author-X-Name-Last: Unger
Title: On unifying concepts for trajectory-based slow invariant attracting manifold computation in kinetic multiscale models
Abstract:
(Chemical) kinetic models in terms of ordinary differential equations correspond to finite-dimensional dissipative dynamical systems involving a multiple time scale structure. Most dimension reduction approaches aimed at a slow mode description of the full system compute approximations of low-dimensional attracting slow invariant manifolds and parameterize these manifolds in terms of a subset of chosen chemical species, the so called reaction progress variables. The invariance property suggests a slow invariant manifold to be constructed as (a bundle of) solution trajectories of suitable ordinary differential equation initial or boundary value problems. The focus of this work is on a discussion and exploitation for deeper insight of unifying geometric and analytical issues of various approaches to trajectory-based numerical approximation techniques of slow invariant manifolds that are in practical use for model reduction in chemical kinetics. Two basic concepts are pointed out reducing various model reduction approaches to a common denominator. In particular, we discuss our recent trajectory optimization approach in the light of these two concepts. We newly relate both of them within our variational boundary value viewpoint, propose a Hamiltonian formulation and conjecture its relation to conservation laws, (partial) integrability and symmetry issues as novel viewpoints on dimension reduction approaches that might open up new deep perspectives and approaches to the problem from dynamical systems theory.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 87-112
Issue: 2
Volume: 22
Year: 2016
Month: 3
X-DOI: 10.1080/13873954.2016.1141219
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1141219
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:2:p:87-112
Template-Type: ReDIF-Article 1.0
Author-Name: Xuehai Wang
Author-X-Name-First: Xuehai
Author-X-Name-Last: Wang
Author-Name: Feng Ding
Author-X-Name-First: Feng
Author-X-Name-Last: Ding
Title: Modelling and multi-innovation parameter identification for Hammerstein nonlinear state space systems using the filtering technique
Abstract:
This article focuses the problem of the modelling and identification for Hammerstein state space systems with coloured noise. In order to jointly estimate the system parameters and states, a filtering-based multi-innovation stochastic gradient algorithm is developed by combining the filtering technique with the multi-innovation identification theory. The key is that the estimation of the system parameters uses the estimated states, and the estimation of the states uses the preceding parameter estimates. The given examples confirm that the proposed algorithm can provide more accurate parameter estimates than the hierarchical multi-innovation stochastic gradient algorithm.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 113-140
Issue: 2
Volume: 22
Year: 2016
Month: 3
X-DOI: 10.1080/13873954.2016.1142455
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1142455
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:2:p:113-140
Template-Type: ReDIF-Article 1.0
Author-Name: Jianhua Tang
Author-X-Name-First: Jianhua
Author-X-Name-Last: Tang
Author-Name: Linfang Qian
Author-X-Name-First: Linfang
Author-X-Name-Last: Qian
Title: Numerical study of forebody wake effect on axisymmetric parachute opening shock and drag reduction
Abstract:
Parachute–forebody distance is a parameter which is amongst the most critical factors to be considered in forebody wake effect. In this study, a new axisymmetric parachute–forebody coupling model is developed. Axisymmetric wrinkling membrane element is built to assess the dynamic response of the parachute canopy membrane under fluid pressure. Besides, fluid model and its further implementation on the fluid structure analysis are discussed. With the proposed method, the wake effect on both the opening shock during inflation state and the drag reduction during steady state can be obtained efficiently. Finally, numerical model is validated with published experimental result and further employed to investigate the influence of distance parameters on fluid–parachute coupling behaviour. On the basis of numerical results, failure distance during the inflation process and critical forebody–parachute distance are determined. The results show that forebody–parachute distance has a strong influence on flow behaviour around the parachute in both inflation state and steady descent state.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 141-159
Issue: 2
Volume: 22
Year: 2016
Month: 3
X-DOI: 10.1080/13873954.2016.1149492
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1149492
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:2:p:141-159
Template-Type: ReDIF-Article 1.0
Author-Name: Asoke Kumar Bhunia
Author-X-Name-First: Asoke Kumar
Author-X-Name-Last: Bhunia
Author-Name: Ali Akbar Shaikh
Author-X-Name-First: Ali Akbar
Author-X-Name-Last: Shaikh
Title: Investigation of two-warehouse inventory problems in interval environment under inflation via particle swarm optimization
Abstract:
In this paper, a two-warehouse inventory problem has been investigated under inflation with different deterioration effects in two separate warehouses (rented warehouse, RW, and owned warehouse, OW). The objective of this investigation is to determine the lot-size of the cycle of the two-warehouse inventory system by minimizing the average cost of the system. Considering different inventory policies, the corresponding models have been formulated for linear trend in demand and interval valued cost parameters. In OW, shortages, if any, are allowed and partially backlogged with a variable rate dependent on the duration of the waiting time up to the arrival of the next lot. The corresponding optimization problems have been formulated as non-linear constrained optimization problems with interval parameters. These problems have been solved by an efficient soft computing method, viz. practical swarm optimization. To illustrate the model, a numerical example has been solved with different partially backlogging rates. Then to study the effect of changes of different system parameters on the optimal policy, sensitivity analyses have been carried out graphically by changing one parameter at a time and keeping the others at their original values. Finally, a fruitful conclusion has been reached regarding the selection of an appropriate inventory policy of the two-warehouse system.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 160-179
Issue: 2
Volume: 22
Year: 2016
Month: 3
X-DOI: 10.1080/13873954.2016.1150860
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1150860
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:2:p:160-179
Template-Type: ReDIF-Article 1.0
Author-Name: G. Alì
Author-X-Name-First: G.
Author-X-Name-Last: Alì
Author-Name: N. Banagaaya
Author-X-Name-First: N.
Author-X-Name-Last: Banagaaya
Author-Name: W.H.A. Schilders
Author-X-Name-First: W.H.A.
Author-X-Name-Last: Schilders
Author-Name: C. Tischendorf
Author-X-Name-First: C.
Author-X-Name-Last: Tischendorf
Title: Index-aware model order reduction for differential-algebraic equations
Abstract:
We introduce a model order reduction (MOR) procedure for differential-algebraic equations, which is based on the intrinsic differential equation contained in the starting system and on the remaining algebraic constraints. The decoupling procedure in differential and algebraic part is based on the projector and matrix chain which leads to the definition of tractability index. The differential part can be reduced by using any MOR method, we use Krylov-based projection methods to illustrate our approach. The reduction on the differential part induces a reduction on the algebraic part. In this paper, we present the method for index-1 differential-algebraic equations. We implement numerically this procedure and show numerical evidence of its validity.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 345-373
Issue: 4
Volume: 20
Year: 2014
Month: 7
X-DOI: 10.1080/13873954.2013.829501
File-URL: http://hdl.handle.net/10.1080/13873954.2013.829501
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:4:p:345-373
Template-Type: ReDIF-Article 1.0
Author-Name: J. Deutscher
Author-X-Name-First: J.
Author-X-Name-Last: Deutscher
Author-Name: Ch. Harkort
Author-X-Name-First: Ch.
Author-X-Name-Last: Harkort
Title: Structure-preserving approximation of distributed-parameter second-order systems using Krylov subspaces
Abstract:
In this article, the approximation of linear second-order distributed-parameter systems (DPS) is considered using a Galerkin approach. The resulting finite-dimensional approximation model also has a second-order structure and preserves the stability as well as the passivity. Furthermore, by extending the Krylov subspace methods for finite-dimensional systems of second order to DPS, the basis vectors of the Galerkin projection are determined such that the transfer behaviour of the DPS can be approximated by using moment matching. The structure-preserving approximation of an Euler–Bernoulli beam with Kelvin–Voigt damping demonstrates the results of the article.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 395-413
Issue: 4
Volume: 20
Year: 2014
Month: 7
X-DOI: 10.1080/13873954.2013.833524
File-URL: http://hdl.handle.net/10.1080/13873954.2013.833524
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:4:p:395-413
Template-Type: ReDIF-Article 1.0
Author-Name: Nikolaus Euler-Rolle
Author-X-Name-First: Nikolaus
Author-X-Name-Last: Euler-Rolle
Author-Name: Stefan Jakubek
Author-X-Name-First: Stefan
Author-X-Name-Last: Jakubek
Author-Name: Günter Offner
Author-X-Name-First: Günter
Author-X-Name-Last: Offner
Title: Model order reduction by projection applied to the universal Reynolds equation
Abstract:
The approach presented in this paper yields a reduced order solution to the universal Reynolds equation for incompressible fluids, which is valid in lubrication as well as in cavitation regions, applied to oil-film lubricated journal bearings in internal combustion engines. The extent of cavitation region poses a free boundary condition to the problem and is determined by an iterative spatial evaluation of a superposed modal solution. Using a Condensed Galerkin and Petrov–Galerkin method, the number of degrees of freedom of the original grid is reduced to obtain a fast but still accurate short-term prediction of the solution. Based on the assumption that a detailed solution of a previous combustion cycle is available, a basis and an optimal test space for the Galerkin method is generated. The resulting reduced order model is efficiently exploited in a time-saving evaluation of the Jacobian matrix describing the elastohydrodynamic coupling in a multi-body dynamics simulation using flexible components. Finally, numerical results are presented for a single crankshaft main bearing of typical dimensions.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 374-394
Issue: 4
Volume: 20
Year: 2014
Month: 7
X-DOI: 10.1080/13873954.2013.838587
File-URL: http://hdl.handle.net/10.1080/13873954.2013.838587
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:4:p:374-394
Template-Type: ReDIF-Article 1.0
Author-Name: Jürgen Geiser
Author-X-Name-First: Jürgen
Author-X-Name-Last: Geiser
Title: Model order reduction for numerical simulation of particle transport based on numerical integration approaches
Abstract:
In this article, we present a non-linear model order reduction (MOR) method based on a linearization technique for a model of particle transport. Historically, non-linear differential equations have been applied to model particle transport. Such non-linear differential equations are expensive and time-consuming to solve. This is a motivation for reducing such a model, based on molecular collisions for heavy particle transport in plasma reactors. Here, we reduce the order by linearization with numerical integration approaches and obtain a controllable and calculable transport–reaction model.We linearize the transport model of the heavy particles with numerical fixed point schemes to a general linear control systems (GLCSs); see M.A. Lieberman and A.J. Lichtenberg [Principle of Plasma Discharges and Materials Processing, 2nd ed., Wiley-Interscience, 2005]. Such linearization allows modelling the collision of the plasma reactor by a system of ordinary differential equations; see the models in M. Ohring [Materials Science of Thin Films, 2nd ed., Academic Press, San Diego, CA, 2002]. Because of their non-linearity, we extend the linear splitting methods with linearization techniques to solve these non-linear equations. Numerical simulations are used to validate this modelling and linearization approach.The contribution is to reuse linear reaction models without neglecting the delicate extension to non-linear reaction models. With the help of higher-order quadrature rules, e.g. Simpson’s rule, we obtain sufficient accuracy and replace the non-linear models by a simpler lower-order linear model.Numerical simulations are presented to validate the coupling ideas of the linearized model.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 317-344
Issue: 4
Volume: 20
Year: 2014
Month: 7
X-DOI: 10.1080/13873954.2013.859159
File-URL: http://hdl.handle.net/10.1080/13873954.2013.859159
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:4:p:317-344
Template-Type: ReDIF-Article 1.0
Author-Name: Zhi-Hua Xiao
Author-X-Name-First: Zhi-Hua
Author-X-Name-Last: Xiao
Author-Name: Yao-Lin Jiang
Author-X-Name-First: Yao-Lin
Author-X-Name-Last: Jiang
Title: Dimension reduction for second-order systems by general orthogonal polynomials
Abstract:
In this article, we discuss the time-domain dimension reduction methods for second-order systems by general orthogonal polynomials, and present a structure-preserving dimension reduction method for second-order systems. The resulting reduced systems not only preserve the second-order structure but also guarantee the stability under certain conditions. The error estimate of the reduced models is also given. The effectiveness of the proposed methods is demonstrated by three test examples.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 414-432
Issue: 4
Volume: 20
Year: 2014
Month: 7
X-DOI: 10.1080/13873954.2013.867274
File-URL: http://hdl.handle.net/10.1080/13873954.2013.867274
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:4:p:414-432
Template-Type: ReDIF-Article 1.0
Author-Name: Jürgen Schmiegel
Author-X-Name-First: Jürgen
Author-X-Name-Last: Schmiegel
Title: Ambit fields: a stochastic modelling approach
Abstract:
This paper reviews some recent developments in the field of ambit stochastics with focus on modelling applications. The great flexibility and mathematical tractability of ambit fields is illustrated by a wide range of applications, covering such diverse areas as turbulence, tumour growth and finance.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 372-386
Issue: 4
Volume: 24
Year: 2018
Month: 7
X-DOI: 10.1080/13873954.2018.1488738
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1488738
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:4:p:372-386
Template-Type: ReDIF-Article 1.0
Author-Name: Markus Schörgenhumer
Author-X-Name-First: Markus
Author-X-Name-Last: Schörgenhumer
Author-Name: Alexander Humer
Author-X-Name-First: Alexander
Author-X-Name-Last: Humer
Title: Smoothed particle hydrodynamics and modal reduction for efficient fluid–structure interaction
Abstract:
From wind turbines to capillary blood flow, problems of fluid–structure interaction occur across different scales of length and time. Owed to the multiple scales involved, the inherent complexity of coupled fluid and structural dynamics requires advanced numerical methods for the computational analysis. The proposed method relies on the coupling of modally reduced flexible multibody systems with fluids represented by the smoothed particle hydrodynamics method. A reduced-order basis is employed to describe small flexible deformation of a structural component relative to its large rigid body motion that is represented by a body-fixed frame. An efficient evaluation of the surface deformation of the bodies involved is a vital ingredient for the coupling. Conventional approaches suffer from the drawback of flexible deformation being represented in a body-fixed local frame. The generalized component mode synthesis, in which the total displacement is interpolated, mitigates this computational limitation. The linear relation between generalized coordinates and the total displacement allows the coupling forces to be evaluated within the parallel fluid framework. Only the reduced set of equations of motion is solved on the solid side using an implicit time integration scheme with possibly large time-steps, whereas the particle-based fluid simulation relies on a fast explicit scheme.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 387-408
Issue: 4
Volume: 24
Year: 2018
Month: 7
X-DOI: 10.1080/13873954.2018.1488739
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1488739
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:4:p:387-408
Template-Type: ReDIF-Article 1.0
Author-Name: Pavol Bauer
Author-X-Name-First: Pavol
Author-X-Name-Last: Bauer
Author-Name: Stefan Engblom
Author-X-Name-First: Stefan
Author-X-Name-Last: Engblom
Author-Name: Sanja Mikulovic
Author-X-Name-First: Sanja
Author-X-Name-Last: Mikulovic
Author-Name: Aleksandar Senek
Author-X-Name-First: Aleksandar
Author-X-Name-Last: Senek
Title: Multiscale modelling via split-step methods in neural firing
Abstract:
Neuronal models based on the Hodgkin–Huxley equation form a fundamental framework in the field of computational neuroscience. While the neuronal state is often modelled deterministically, experimental recordings show stochastic fluctuations, presumably driven by molecular noise from the underlying microphysical conditions. In turn, the firing of individual neurons gives rise to an electric field in extracellular space, also thought to affect the firing pattern of nearby neurons.We develop a multiscale model which combines a stochastic ion channel gating process taking place on the neuronal membrane, together with the propagation of an action potential along the neuronal structure. We also devise a numerical method relying on a split-step strategy which effectively couples these two processes and we experimentally test the feasibility of this approach. We finally also explain how the approach can be extended with Maxwell’s equations to allow the potential to be propagated in extracellular space.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 409-425
Issue: 4
Volume: 24
Year: 2018
Month: 7
X-DOI: 10.1080/13873954.2018.1488740
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1488740
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:4:p:409-425
Template-Type: ReDIF-Article 1.0
Author-Name: Jürgen Geiser
Author-X-Name-First: Jürgen
Author-X-Name-Last: Geiser
Title: Multiscale modelling and splitting approaches for fluids composed of Coulomb-interacting particles
Abstract:
We consider fluids composed of Coulomb-interacting particles, which aremodelled by the Fokker--Planck equation with a collision operator.Based on modelling the transport and collision of the particles,we propose new, computationally efficient, algorithms based on splitting the equations of motion into a global Newtonian transport equation, where the effects of an external electric field are considered, and a local Coulomb interaction stochastic differential equation, which determinesthe new velocities of the particle. Two different numerical schemes, one deterministic and the other stochastic, as well as an Hamiltonian splitting approach, are proposed for coupling the interactionand transport equations. Results are presented for two- and multi-particle systems with different approximations for the Coulomb interaction.Methodologically, the transport part is modelled by thekinetic equations and the collision part is modelled bythe Langevin equations with Coulomb collisions.Such splitting approaches allow concentrating on different solver methodsfor each different part. Further, we solve multiscale problems involving an external electrostatic field.We apply a multiscale approach so that we can decompose the different time-scales of the transport and the collision parts.We discuss the benefits of the different splitting approaches and theirnumerical analysis.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 318-371
Issue: 4
Volume: 24
Year: 2018
Month: 7
X-DOI: 10.1080/13873954.2018.1488741
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1488741
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:4:p:318-371
Template-Type: ReDIF-Article 1.0
Author-Name: Jürgen Geiser
Author-X-Name-First: Jürgen
Author-X-Name-Last: Geiser
Title: Modelling and analysis of multiscale systems related to fluid dynamical problems
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 315-317
Issue: 4
Volume: 24
Year: 2018
Month: 7
X-DOI: 10.1080/13873954.2018.1488743
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1488743
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:4:p:315-317
Template-Type: ReDIF-Article 1.0
Author-Name: James R. Phillips
Author-X-Name-First: James R.
Author-X-Name-Last: Phillips
Author-Name: Farid Amirouche
Author-X-Name-First: Farid
Author-X-Name-Last: Amirouche
Title: Corrigendum: a momentum form of Kane’s equations for scleronomic systems
Abstract:
In the authors’ previously published paper, ‘A Momentum form of Kane’s equations for scleronomic systems’ (https://doi.org/10.1080/13873954.2017.1385638), the discussion defining the procedure for calculating nonworking constraint forces is flawed. In this corrigendum, we supply a corrected discussion and procedure, illustrated with an example.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 426-429
Issue: 4
Volume: 24
Year: 2018
Month: 7
X-DOI: 10.1080/13873954.2018.1496460
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1496460
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:4:p:426-429
Template-Type: ReDIF-Article 1.0
Author-Name: Jingjing Du
Author-X-Name-First: Jingjing
Author-X-Name-Last: Du
Author-Name: Lei Zhang
Author-X-Name-First: Lei
Author-X-Name-Last: Zhang
Author-Name: Junfeng Chen
Author-X-Name-First: Junfeng
Author-X-Name-Last: Chen
Author-Name: Jian Li
Author-X-Name-First: Jian
Author-X-Name-Last: Li
Author-Name: Changping Zhu
Author-X-Name-First: Changping
Author-X-Name-Last: Zhu
Title: Multi-model predictive control of Hammerstein-Wiener systems based on balanced multi-model partition
Abstract:
Model analysis of Hammerstein-Wiener systems has been made, and it is found that the included angle is applicable to such systems to measure the non-linearity. Then, a dichotomy gridding algorithm is proposed based on the included angle. Supporting by the gridding algorithm, a balanced multi-model partition method is put forward to partition a Hammerstein-Wiener system into a set of local linear models. For each linear model, a linear model predictive controller (MPC) is designed. After that, a multi-MPC is composed of the linear MPCs via soft switching. Thus, a complex non-linear control problem is transformed into a set of linear control problems, which simplifies the original control problem and improves the control performance. Two non-linear systems are built into Hammerstein-Wiener models and investigated using the proposed methods. Simulations demonstrate that the proposed gridding and partition methods are effective, and the resulted multi-MPC controller has satisfactory performance in both set-point tracking and disturbance rejection control.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 333-353
Issue: 4
Volume: 25
Year: 2019
Month: 7
X-DOI: 10.1080/13873954.2019.1624580
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1624580
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:4:p:333-353
Template-Type: ReDIF-Article 1.0
Author-Name: P. Madhavasarma
Author-X-Name-First: P.
Author-X-Name-Last: Madhavasarma
Author-Name: M. Sridevi
Author-X-Name-First: M.
Author-X-Name-Last: Sridevi
Author-Name: S. Kumaravel
Author-X-Name-First: S.
Author-X-Name-Last: Kumaravel
Author-Name: P. Veeraragavan
Author-X-Name-First: P.
Author-X-Name-Last: Veeraragavan
Title: An electrical stimulation data based model to predict the healing period of fractured limb
Abstract:
In this work, diagnosing of reunion of human tibia fracture across limbs using a simple mathematical model is demonstrated. At present in practice, the fracture reunion is predicted using repeated radiographs. Frequent exposure to such radiation causes harmful health effects in patients. Hence, as an alternative, modelling technique using electrical data recorded across patients stimulated with DC electric voltage of range 0.1–1V is proposed. Various model structures, namely P1D and P1DZ models were tried. An error analysis was performed and it was observed that the measured data fitted P1DZ model with an error less than 5%. Model parameters namely process gain and time constant were observed. When the model parameter process gain becomes constant, the time constant reduces significantly indicating the healing of fracture. Reunion was also confirmed with simultaneously taken radiographs. The fact that human bone is a biological semi-conductor therefore exhibits electrical properties and bone does behave like a capacitor is proved by empirical methods in our study is the novelty of the work.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 354-375
Issue: 4
Volume: 25
Year: 2019
Month: 7
X-DOI: 10.1080/13873954.2019.1651341
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1651341
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:4:p:354-375
Template-Type: ReDIF-Article 1.0
Author-Name: Qi Wang
Author-X-Name-First: Qi
Author-X-Name-Last: Wang
Author-Name: Yinsheng Luo
Author-X-Name-First: Yinsheng
Author-X-Name-Last: Luo
Author-Name: Xiaoxin Han
Author-X-Name-First: Xiaoxin
Author-X-Name-Last: Han
Title: Research on estimation model of the battery state of charge in a hybrid electric vehicle based on the classification and regression tree
Abstract:
In order to achieve the accurate estimation of state of charge (SOC) of the battery in a hybrid electric vehicle (HEV), this paper proposed a new estimation model based on the classification and regression tree (CART) which belongs to a kind of decision tree. The basic principle and modelling process of the CART decision tree were introduced in detail in this paper, and we used the voltage, current, and temperature of the battery in an HEV to estimate the value of SOC under the driving cycle. Meanwhile, we took the energy feedback of the HEV under the regenerative braking into consideration. The simulation data and experimental data were used to test the effectiveness of the estimation model of CART, and the results indicate that the proposed estimation model has high accuracy, the relative error of simulation is within 0.035, while the relative error of experiment is less than 0.05.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 376-396
Issue: 4
Volume: 25
Year: 2019
Month: 7
X-DOI: 10.1080/13873954.2019.1655654
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1655654
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:4:p:376-396
Template-Type: ReDIF-Article 1.0
Author-Name: Anna I. Pózna
Author-X-Name-First: Anna I.
Author-X-Name-Last: Pózna
Author-Name: Attila Fodor
Author-X-Name-First: Attila
Author-X-Name-Last: Fodor
Author-Name: Katalin M. Hangos
Author-X-Name-First: Katalin M.
Author-X-Name-Last: Hangos
Title: Model-based fault detection and isolation of non-technical losses in electrical networks
Abstract:
A model-based diagnostic method is proposed for detecting and isolating non-technical losses (illegal loads) in low voltage electrical grids of one transformer area. The proposed method uses a simple static linear model of the network and it is based on analysing the differences between the measured and model-predicted voltages. As a preliminary off-line step of the diagnosis, a powerful electrical decomposition method is proposed, which breaks down the overall network to subsystems with one feeder layout enabling to make the computation efficient. The uncertainty in the model parameters together with the measurement uncertainties are also taken into account to make the approach applicable in real-world cases. The proposed method is able to detect and localize multiple illegal loads, and the amount of the illegal consumption can also be estimated. The operation and the diagnostic capabilities of the method are illustrated on a case study using the IEEE 2015 European Low Voltage Test Feeder.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 397-428
Issue: 4
Volume: 25
Year: 2019
Month: 7
X-DOI: 10.1080/13873954.2019.1655066
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1655066
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:4:p:397-428
Template-Type: ReDIF-Article 1.0
Author-Name: M. Mohammadpour
Author-X-Name-First: M.
Author-X-Name-Last: Mohammadpour
Author-Name: Hassan S. Bakouch
Author-X-Name-First: Hassan S.
Author-X-Name-Last: Bakouch
Author-Name: S. Ramzani
Author-X-Name-First: S.
Author-X-Name-Last: Ramzani
Title: An integer-valued bilinear time series model via two random operators
Abstract:
This paper presents a new stationary integer-valued bilinear time series model of the first order by mixing the thinning and Pegram operators. Some statistical properties of the model are obtained, involving the conditional moments, autocovariance and spectral density function. Estimation of the model parameters is discussed using the Yule-Walker and conditional least squares methods with a simulation study for evaluating the performance of those estimators. Applicability of the process is investigated using a practical count data set with comparing the model to a competitive bilinear model using some marginal distributions of innovations. Issue of forecasting data is discussed under the proposed model.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 429-446
Issue: 4
Volume: 25
Year: 2019
Month: 7
X-DOI: 10.1080/13873954.2019.1652655
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1652655
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:4:p:429-446
Template-Type: ReDIF-Article 1.0
Author-Name: Cijun Shuai
Author-X-Name-First: Cijun
Author-X-Name-Last: Shuai
Author-Name: Pei Feng
Author-X-Name-First: Pei
Author-X-Name-Last: Feng
Author-Name: Chengde Gao
Author-X-Name-First: Chengde
Author-X-Name-Last: Gao
Author-Name: Ying Zhou
Author-X-Name-First: Ying
Author-X-Name-Last: Zhou
Author-Name: Shuping Peng
Author-X-Name-First: Shuping
Author-X-Name-Last: Peng
Title: Simulation of dynamic temperature field during selective laser sintering of ceramic powder
Abstract:
It is difficult to obtain the dynamic temperature field and the variation pattern with the experimental method as the temperature field changes very fast in the laser sintering process. In this study, a mathematical model for the dynamic temperature field was established during selective laser sintering (SLS) with nano-hydroxyapatite (HAP) ceramic powder. The dynamic loading of a moving laser heat source with a Gaussian distribution was realized with ANSYS Parameter Design Language. The variation pattern of a three-dimensional transient temperature field at different speeds of the moving laser heat source was analysed as the change of thermal physical parameters with temperature was taken into account in the developed model. The results show that the maximum temperature point on the sintered layer surface is slightly lagged from the laser spot centre with the moving laser heat source when the offset distance is 0.4 mm, laser power is 10 W, laser spot diameter is 2 mm and laser speed is 200 mm/min. The temperature decreases rapidly with the increase of sintering depth. The temperature field that the characteristic microstructure of the sintered parts represents coincides with that by the analysis with finite element calculation. This study may provide useful guidance for selecting the reasonable processing parameters during SLS.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 1-11
Issue: 1
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2012.689769
File-URL: http://hdl.handle.net/10.1080/13873954.2012.689769
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:1:p:1-11
Template-Type: ReDIF-Article 1.0
Author-Name: Yun Zeng
Author-X-Name-First: Yun
Author-X-Name-Last: Zeng
Author-Name: Yakun Guo
Author-X-Name-First: Yakun
Author-X-Name-Last: Guo
Author-Name: Lixiang Zhang
Author-X-Name-First: Lixiang
Author-X-Name-Last: Zhang
Author-Name: Tianmao Xu
Author-X-Name-First: Tianmao
Author-X-Name-Last: Xu
Author-Name: Hongkui Dong
Author-X-Name-First: Hongkui
Author-X-Name-Last: Dong
Title: Nonlinear hydro turbine model having a surge tank
Abstract:
This article models a hydro turbine based on the dynamic description of the hydraulic system having a surge tank and elastic water hammer. The dynamic of the hydraulic system is transformed from transfer function form into the differential equation model in relative value. This model is then combined with the motion equation of the main servomotor to form the nonlinear model of the hydro turbine, in which the power of the hydro turbine is calculated using algebraic equation. A new control model is thus proposed in which the dynamic of the surge tank is taken as an additional input of control items. As such, the complex hydraulic system is decomposed into a classical one penstock and one machine model with an additional input control. Therefore, the order of the system is descended. As a result, the feasibility of the system is largely improved. The simulated results show that the additional input of the surge tank is effective and the proposed method is realizable.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 12-28
Issue: 1
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2012.689770
File-URL: http://hdl.handle.net/10.1080/13873954.2012.689770
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:1:p:12-28
Template-Type: ReDIF-Article 1.0
Author-Name: Maysam Safe
Author-X-Name-First: Maysam
Author-X-Name-Last: Safe
Author-Name: Seyed Khazraee
Author-X-Name-First: Seyed
Author-X-Name-Last: Khazraee
Author-Name: Payam Setoodeh
Author-X-Name-First: Payam
Author-X-Name-Last: Setoodeh
Author-Name: Abdolhosein Jahanmiri
Author-X-Name-First: Abdolhosein
Author-X-Name-Last: Jahanmiri
Title: Model reduction and optimization of a reactive dividing wall batch distillation column inspired by response surface methodology and differential evolution
Abstract:
Carrying out reaction and separation simultaneously in a reactive dividing wall batch distillation column batch RDWC in the case of ethyl acetate synthesis provides the possibility of separating both products and increasing the equilibrium reaction conversion. Overcoming the known azeotrope conditions, high purity for ethyl acetate and decreasing the batch time compared to simple reactive batch distillation are the advantages of this configuration. The corresponding dynamic simulation is carried out by simultaneously solving the model-associated system of differential and algebraic equations. In this study, the optimal values of the vapour and liquid split ratios are considered as the decision variables in order to maximize the amount of ethyl acetate accumulated during batch time. The optimization strategy is implemented inspired by response surface methodology in which an optimal surface is fitted to the collected data set using differential evolution (DE). The optimal surface relevant algebraic equation is then considered as the reduced form of the complex model and the optimal values are obtained using the DE method.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 29-50
Issue: 1
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2012.691521
File-URL: http://hdl.handle.net/10.1080/13873954.2012.691521
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:1:p:29-50
Template-Type: ReDIF-Article 1.0
Author-Name: Jalal Nazarzadeh
Author-X-Name-First: Jalal
Author-X-Name-Last: Nazarzadeh
Author-Name: Vahid Naeini
Author-X-Name-First: Vahid
Author-X-Name-Last: Naeini
Title: A generalized dynamical model for transformers with saturation and hysteresis effects
Abstract:
This article presents a new generalized non-linear dynamical model of a transformer with saturation and hysteresis effects. The structure of this new model is based on a magnetic equivalent circuit with non-linear reluctance elements. Using this method, accurate models of three- and five-legged transformers with magnetic saturation and hysteresis phenomena of iron core are introduced and inrush current in normal and sequential phase energization techniques are evaluated. Moreover, the effects of neutral resistance, magnetic structure and winding connections on inrush current are determined. In addition, for validation of the proposed model, some numerical simulations are made and compared with other techniques. Simulation results illustrate that the proposed model has high accuracy and efficiency for non-linear dynamical modelling of a transformer.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 51-66
Issue: 1
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2012.695740
File-URL: http://hdl.handle.net/10.1080/13873954.2012.695740
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:1:p:51-66
Template-Type: ReDIF-Article 1.0
Author-Name: David Murray-Smith
Author-X-Name-First: David
Author-X-Name-Last: Murray-Smith
Title: The application of parameter sensitivity analysis methods to inverse simulation models
Abstract:
Knowledge of the sensitivity of inverse solutions to variation of parameters of a model can be very useful in making engineering design decisions. This article describes how parameter sensitivity analysis can be carried out for inverse simulations generated through approximate transfer function inversion methods and also through the use of feedback principles. Emphasis is placed on the use of sensitivity models and the article includes examples and a case study involving a model of an underwater vehicle. It is shown that the use of sensitivity models can provide physical understanding of inverse simulation solutions that is not directly available using parameter sensitivity analysis methods that involve parameter perturbations and response differencing.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 67-90
Issue: 1
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2012.696271
File-URL: http://hdl.handle.net/10.1080/13873954.2012.696271
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:1:p:67-90
Template-Type: ReDIF-Article 1.0
Author-Name: Ngoc Minh Trang Vu
Author-X-Name-First: Ngoc Minh Trang
Author-X-Name-Last: Vu
Author-Name: Laurent Lefèvre
Author-X-Name-First: Laurent
Author-X-Name-Last: Lefèvre
Author-Name: Bernhard Maschke
Author-X-Name-First: Bernhard
Author-X-Name-Last: Maschke
Title: A structured control model for the thermo-magneto-hydrodynamics of plasmas in tokamaks
Abstract:
A thermo-magneto-hydrodynamics port-Hamiltonian model is derived for the plasmas in tokamaks. Electromagnetic field and material domain balance equations are expressed in covariant forms, together with the magneto-hydrodynamics interconnection structure connecting them together. The balance equations for the entropy, mass and momentum, as well as closure equations in the material domain, are derived from the Boltzmann equation (kinetic theory). The Gibbs–Duhem equation is used to compute the irreversible entropy source term and to define the interdomain ℜ-field of the model. All derived interdomain couplings in the material domain are represented using Dirac and Stokes–Dirac structures and the resistivity ℜ-field structure. The complete model is summarized in a Bond Graph.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 181-206
Issue: 3
Volume: 22
Year: 2016
Month: 5
X-DOI: 10.1080/13873954.2016.1154874
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1154874
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:3:p:181-206
Template-Type: ReDIF-Article 1.0
Author-Name: F. Hammami
Author-X-Name-First: F.
Author-X-Name-Last: Hammami
Author-Name: S. Ben Mabrouk
Author-X-Name-First: S.
Author-X-Name-Last: Ben Mabrouk
Author-Name: A. Mami
Author-X-Name-First: A.
Author-X-Name-Last: Mami
Title: Modelling and simulation of heat exchange and moisture content in a cereal storage silo
Abstract:
In this paper, a mathematical model is developed based on the heat transfer of stored grains aerated in a cylindrical silo. This work is a part of study that aims to model the whole process of cereal storage system including a dehumidifier. The use of dehumidifier is intended to remove excess moisture from the airflow injected by the ventilator system in the silo filled with wheat, and to keep hygroscopic properties of grain in safe level during the storage period. Temperature and humidity are the two important variables coupled to control the process and to preserve grain quality. The laboratory device permitted us to achieve several tests for different conditions of grain stored in silo without aeration. A simulation of the airflow through the thermal space of the silo and grain parameters has been carried out. The results are reasonably in agreement with experiments and other published data. The system performance is evaluated at critical conditions of storage boundaries.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 207-220
Issue: 3
Volume: 22
Year: 2016
Month: 5
X-DOI: 10.1080/13873954.2016.1157823
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1157823
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:3:p:207-220
Template-Type: ReDIF-Article 1.0
Author-Name: Victorino Sanz
Author-X-Name-First: Victorino
Author-X-Name-Last: Sanz
Author-Name: Alfonso Urquia
Author-X-Name-First: Alfonso
Author-X-Name-Last: Urquia
Author-Name: Alberto Leva
Author-X-Name-First: Alberto
Author-X-Name-Last: Leva
Title: : improving the support for cellular automata modelling in Modelica
Abstract:
CellularAutomataLib is a library developed by the authors to facilitate the description of Cellular Automata (CA) models in Modelica. It supports the description of 1D and 2D CA and their combination with other Modelica models. Modelling versatility and scalability are the main focus in the design. The internal behaviour of CA models is programmed in C, that is consequently hidden to the modelling tool and not considered in the causalization and manipulation of the model. A new version, named CellularAutomataLib2, is presented in this manuscript. The library has been extended to improve the simulation performance, by only evaluating active cells, and to support Lattice Gas Cellular Automata (LGCA) models. The library design and use are discussed. Two models, forest fire spread and the ARGESIM C17 ‘SIR-type Epidemic Spread’, are used to illustrate the functionality of the library. CellularAutomataLib2 is freely available at http://www.euclides.dia.uned.es (under the Modelica License 2).
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 244-264
Issue: 3
Volume: 22
Year: 2016
Month: 5
X-DOI: 10.1080/13873954.2016.1163269
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1163269
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:3:p:244-264
Template-Type: ReDIF-Article 1.0
Author-Name: Jürgen Geiser
Author-X-Name-First: Jürgen
Author-X-Name-Last: Geiser
Title: Multiscale modelling of solute transport through porous media using homogenization and splitting methods
Abstract:
The aim of this paper is to treat multiscale modelling approaches for solute transport through porous media. This involves coupled systems of convection–diffusion–reaction equations that can be homogenized and solved by splitting methods. The topic is very challenging in the case of multiscale model systems, for example, those arising when the evolution of several chemical species involves time-dependent or non-linear mechanisms. Our proposed modelling approach is based on the idea of homogenization of the diffusion, convection and reaction of chemical species in a porous medium to derive macroscopic equations. Based on the existence of multiple timescales, we introduce multiscale methods to model the evolution and obtain solutions. A more detailed analysis shows that such multiscale methods can be treated via the so-called iterative splitting approach. To solve the multiscale model, we propose exact solutions of some submodels, which can be then be taken into account and play an important role in accelerating the numerical computations of the large coupled model. In the first part, we introduce the model and its application. In the second part, we discuss the analytical solutions of the submodels related to fast and analytically solvable convection–reaction equations. The iterative splitting approaches are then discussed for solving the multiple timescale part. Finally, the last part presents some numerical experiments involving real-life test problems in transport–reaction processes.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 221-243
Issue: 3
Volume: 22
Year: 2016
Month: 5
X-DOI: 10.1080/13873954.2016.1163270
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1163270
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:3:p:221-243
Template-Type: ReDIF-Article 1.0
Author-Name: Christoph Froehlich
Author-X-Name-First: Christoph
Author-X-Name-Last: Froehlich
Author-Name: Wolfgang Kemmetmüller
Author-X-Name-First: Wolfgang
Author-X-Name-Last: Kemmetmüller
Author-Name: Andreas Kugi
Author-X-Name-First: Andreas
Author-X-Name-Last: Kugi
Title: Control-oriented modeling of servo-pump driven injection molding machines in the filling and packing phase
Abstract:
Servo-valves or variable displacement pumps are typically used to control conventional hydraulic injection molding machines (IMMs). Recent developments in electrical drive technology allow to utilize servo-motor driven pumps instead, which is beneficial due to their higher energy efficiency. Their dynamic behavior, however, is significantly different compared to the conventional setup. Thus, currently used mathematical models and control concepts cannot be directly applied. This paper presents a computationally efficient and scalable mathematical model of the injection process for these servo-pump driven IMMs. A first-principles model of the injection machine is combined with a phenomenological model describing the injection process, i.e. the compression of the melt and the polymer flow into the mold. The proposed model is tailored to real-time applications and serves as an ideal basis for the design of model-based control strategies. The feasibility of the proposed model is demonstrated by a number of different experiments. They confirm a high model accuracy over the whole operating range for different mold geometries.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 451-474
Issue: 5
Volume: 24
Year: 2018
Month: 9
X-DOI: 10.1080/13873954.2018.1481870
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1481870
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:5:p:451-474
Template-Type: ReDIF-Article 1.0
Author-Name: Manuela Hund
Author-X-Name-First: Manuela
Author-X-Name-Last: Hund
Author-Name: Jens Saak
Author-X-Name-First: Jens
Author-X-Name-Last: Saak
Title: A connection between time domain model order reduction and moment matching for LTI systems
Abstract:
We investigate the time domain model order reduction (MOR) framework using general orthogonal polynomials by Jiang and Chen [1] and extend their idea by exploiting the structure of the corresponding linear system of equations. Identifying an equivalent Sylvester equation, we show a connection to a rational Krylov subspace, and thus to moment matching. This theoretical link between the MOR techniques is illustrated by three numerical examples. For linear time-invariant systems, the link also motivates that the time-domain approach can be at best as accurate as moment matching, since the expansion points are fixed by the choice of the polynomial basis, while in moment matching they can be adapted to the system.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 475-504
Issue: 5
Volume: 24
Year: 2018
Month: 9
X-DOI: 10.1080/13873954.2018.1488742
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1488742
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:5:p:475-504
Template-Type: ReDIF-Article 1.0
Author-Name: Poulami Dalapati
Author-X-Name-First: Poulami
Author-X-Name-Last: Dalapati
Author-Name: Piyush Agarwal
Author-X-Name-First: Piyush
Author-X-Name-Last: Agarwal
Author-Name: Animesh Dutta
Author-X-Name-First: Animesh
Author-X-Name-Last: Dutta
Author-Name: Swapan Bhattacharya
Author-X-Name-First: Swapan
Author-X-Name-Last: Bhattacharya
Title: Dynamic process scheduling and resource allocation in distributed environment: an agent-based modelling and simulation
Abstract:
This paper addresses the issues concerning resource allocation and process scheduling in a dynamic environment, where resources are distributed and availability of them is uncertain. In this context, we introduce a new multi-agent-based resource allocation and process scheduling approach, where agents communicate and cooperate among themselves to produce an optimal schedule. A distributed constraint optimization problem-based model in accordance with Markov Decision Process is proposed in this regard. We overcome the hardship of existing centralized approach and our technique optimizes not only the process completion delay but also the number of resources being idle, which is much more beneficial. Apart from the theoretical approach, we take a case study in its practical application domain to validate our claim. Analysis and experimental results show that this proposed method outperforms the state-of-the-art methods and bridges the gap between theory and its applications.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 505-525
Issue: 5
Volume: 24
Year: 2018
Month: 9
X-DOI: 10.1080/13873954.2018.1512504
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1512504
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:5:p:505-525
Template-Type: ReDIF-Article 1.0
Author-Name: Wanyang Dai
Author-X-Name-First: Wanyang
Author-X-Name-Last: Dai
Title: Platform modelling and scheduling game with multiple intelligent cloud-computing pools for big data
Abstract:
We develop a generic game platform that can be used to model various real-world systems with multiple intelligent cloud-computing pools and parallel-queues for resources-competing users. Inside the platform, the software structure is modelled as Blockchain. All the users are associated with Big Data arrival streams whose random dynamics is modelled by triply stochastic renewal reward processes (TSRRPs). Each user may be served simultaneously by multiple pools while each pool with parallel-servers may also serve multi-users at the same time via smart policies in the Blockchain, e.g. a Nash equilibrium point myopically at each fixed time to a game-theoretic scheduling problem. To illustrate the effectiveness of our game platform, we model the performance measures of its internal data flow dynamics (queue length and workload processes) as reflecting diffusion with regime-switchings (RDRSs) under our scheduling policies. By RDRS models, we can prove our myopic game-theoretic policy to be an asymptotic Pareto minimal-dual-cost Nash equilibrium one globally over the whole time horizon to a randomly evolving dynamic game problem. Iterative schemes for simulating our multi-dimensional RDRS models are also developed with the support of numerical comparisons.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 526-572
Issue: 5
Volume: 24
Year: 2018
Month: 9
X-DOI: 10.1080/13873954.2018.1516677
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1516677
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:5:p:526-572
Template-Type: ReDIF-Article 1.0
Author-Name: Thomas Specker
Author-X-Name-First: Thomas
Author-X-Name-Last: Specker
Author-Name: Michael Buchholz
Author-X-Name-First: Michael
Author-X-Name-Last: Buchholz
Author-Name: Klaus Dietmayer
Author-X-Name-First: Klaus
Author-X-Name-Last: Dietmayer
Title: Modelling of unilateral constraints using power-based restriction functions within Lagrangian mechanics
Abstract:
The consideration of unilateral contacts within multi-body systems is a common but also difficult task. Established modelling approaches such as the rigid body theory or the Hertzian contact are suitable for single-body systems but show serious problems with increasing system complexity. Indeed, there are different approaches to extend the existing models to multi-body systems, but with a growing number of contacts and the consideration of tangential friction, those enhancements are hardly applicable, showing numeric problems or becoming unmanageable. Thus, to overcome these limitations, a new modelling approach for unilateral contacts defined by power-based restriction functions is proposed in this contribution. The proposed contact model is based on continuous functions, making it numerically robust as well as applicable within Lagrangian mechanics. The approach is easily applicable and even remains manageable for multiple contacts since each constraint can be independently adapted by four physical parameters. The simple applicability and generalizability of the approach is demonstrated by several examples.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 509-534
Issue: 6
Volume: 21
Year: 2015
Month: 11
X-DOI: 10.1080/13873954.2015.1016976
File-URL: http://hdl.handle.net/10.1080/13873954.2015.1016976
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:6:p:509-534
Template-Type: ReDIF-Article 1.0
Author-Name: Christina Kossow
Author-X-Name-First: Christina
Author-X-Name-Last: Kossow
Author-Name: Stefan Rybacki
Author-X-Name-First: Stefan
Author-X-Name-Last: Rybacki
Author-Name: Thomas Millat
Author-X-Name-First: Thomas
Author-X-Name-Last: Millat
Author-Name: Katja Rateitschak
Author-X-Name-First: Katja
Author-X-Name-Last: Rateitschak
Author-Name: Robert Jaster
Author-X-Name-First: Robert
Author-X-Name-Last: Jaster
Author-Name: Adelinde M. Uhrmacher
Author-X-Name-First: Adelinde M.
Author-X-Name-Last: Uhrmacher
Author-Name: Olaf Wolkenhauer
Author-X-Name-First: Olaf
Author-X-Name-Last: Wolkenhauer
Title: An explicit numerical scheme to efficiently simulate molecular diffusion in environments with dynamically changing barriers
Abstract:
Despite temporal changes in the quantities of molecules, the functioning of cells also depends on their distribution within cells and in their extracellular environment. The dynamics of molecules are often governed by diffusion in heterogeneous environments consisting of dynamically changing impenetrable barriers (excluded volumes). This provides a challenge for efficient simulations of cellular processes with large numbers of molecules. To model the diffusion of molecular mass in consideration of excluded volumes, we here present an explicit numerical scheme that approximates the diffusion equation by using cellular automata. Because this approach represents molecular diffusion at the macroscopic scale, it is more amenable for efficient simulations than comparable microscopic approaches that treat diffusing molecules individually. In contrast to implicit numerical schemes (macroscopic approach), our approach is capable of accounting for excluded volumes, even if those exhibit a dynamic of their own, without increasing computational costs. The presented approach can easily be integrated into certain types of spatio-temporal multiscale models, as demonstrated by an existing model investigating cancer progression. Thereby, it allows to take the spatial effects of a heterogeneous environment on diffusing molecules into account.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 535-559
Issue: 6
Volume: 21
Year: 2015
Month: 11
X-DOI: 10.1080/13873954.2015.1033823
File-URL: http://hdl.handle.net/10.1080/13873954.2015.1033823
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:6:p:535-559
Template-Type: ReDIF-Article 1.0
Author-Name: Zaid Ahsan
Author-X-Name-First: Zaid
Author-X-Name-Last: Ahsan
Author-Name: Thomas Uchida
Author-X-Name-First: Thomas
Author-X-Name-Last: Uchida
Author-Name: C. P. Vyasarayani
Author-X-Name-First: C. P.
Author-X-Name-Last: Vyasarayani
Title: Galerkin approximations with embedded boundary conditions for retarded delay differential equations
Abstract:
Finite-dimensional approximations are developed for retarded delay differential equations (DDEs). The DDE system is equivalently posed as an initial-boundary value problem consisting of hyperbolic partial differential equations (PDEs). By exploiting the equivalence of partial derivatives in space and time, we develop a new PDE representation for the DDEs that is devoid of boundary conditions. The resulting boundary condition-free PDEs are discretized using the Galerkin method with Legendre polynomials as the basis functions, whereupon we obtain a system of ordinary differential equations (ODEs) that is a finite-dimensional approximation of the original DDE system. We present several numerical examples comparing the solution obtained using the approximate ODEs to the direct numerical simulation of the original non-linear DDEs. Stability charts developed using our method are compared to existing results for linear DDEs. The presented results clearly demonstrate that the equivalent boundary condition-free PDE formulation accurately captures the dynamic behaviour of the original DDE system and facilitates the application of control theory developed for systems governed by ODEs.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 560-572
Issue: 6
Volume: 21
Year: 2015
Month: 11
X-DOI: 10.1080/13873954.2015.1043741
File-URL: http://hdl.handle.net/10.1080/13873954.2015.1043741
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:6:p:560-572
Template-Type: ReDIF-Article 1.0
Author-Name: Alexander Zuyev
Author-X-Name-First: Alexander
Author-X-Name-Last: Zuyev
Author-Name: Oliver Sawodny
Author-X-Name-First: Oliver
Author-X-Name-Last: Sawodny
Title: Modelling and control of a shell structure based on a finite dimensional variational formulation
Abstract:
A mathematical model of a controlled shell structure based on Hamilton’s principle and the generalized Ritz–Galerkin method is proposed in this paper. The problem of minimizing the stress energy is solved explicitly for a static version of this model. For the dynamical system under consideration, a procedure for estimating external disturbances and the state vector is derived. We also propose an observer design scheme and solve the stabilization problem for an arbitrary dimension of the linearized model. This approach allows us to perform control design for double-curved shells of complex geometry by combining analytical computation of the controller parameters with numerical data that represent the reference configuration and modal displacements of the shell. As an example, the parameters of our model are validated by results of a finite element analysis for the Stuttgart SmartShell structure.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 591-612
Issue: 6
Volume: 21
Year: 2015
Month: 11
X-DOI: 10.1080/13873954.2015.1065278
File-URL: http://hdl.handle.net/10.1080/13873954.2015.1065278
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:6:p:591-612
Template-Type: ReDIF-Article 1.0
Author-Name: Zhen-Zhong Qi
Author-X-Name-First: Zhen-Zhong
Author-X-Name-Last: Qi
Author-Name: Yao-Lin Jiang
Author-X-Name-First: Yao-Lin
Author-X-Name-Last: Jiang
Author-Name: Zhi-Hua Xiao
Author-X-Name-First: Zhi-Hua
Author-X-Name-Last: Xiao
Title: Structure-preserving model order reduction based on Laguerre–SVD for coupled systems
Abstract:
In this paper, we present a model order reduction (MOR) method based on Laguerre polynomials and singular value decomposition (SVD) for coupled systems in the frequency domain. By constructing projection matrices from the global perspective and then blockdiagonalizing them, the reduced system is produced, which not only retains the structure of the original system, but also matches the first several Laguerre coefficients. In addition, the connection between our algorithm and the moment matching approximation is also discussed. The error estimation of our method is given as well. Besides, the stability of the reduced system is also studied. Finally, two numerical examples are provided to verify the effectiveness of our algorithm.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 573-590
Issue: 6
Volume: 21
Year: 2015
Month: 11
X-DOI: 10.1080/13873954.2015.1065279
File-URL: http://hdl.handle.net/10.1080/13873954.2015.1065279
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:6:p:573-590
Template-Type: ReDIF-Article 1.0
Author-Name: D.D. Riley
Author-X-Name-First: D.D.
Author-X-Name-Last: Riley
Author-Name: X. Koutsoukos
Author-X-Name-First: X.
Author-X-Name-Last: Koutsoukos
Title: Probabilistic verification of a biodiesel production system using statistical model checking
Abstract:
Biochemical system designers are increasingly using formal modelling, simulation, and verification methods to improve the understanding of complex systems. Probabilistic models can incorporate realistic stochastic dynamics, but creating and analysing probabilistic models in a formal way is challenging. In this work, we present a stochastic model of biodiesel production that incorporates an inexpensive test of fuel quality, and we validate the model using statistical model checking, which can be used to evaluate simple or complex temporal properties efficiently. We also describe probabilistic simulation and analysis techniques for stochastic hybrid system (SHS) models to demonstrate the properties of our model. We introduce a variety of properties for various configurations of the reactor as well as results of testing our model against the properties.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 452-469
Issue: 5
Volume: 20
Year: 2014
Month: 9
X-DOI: 10.1080/13873954.2013.832333
File-URL: http://hdl.handle.net/10.1080/13873954.2013.832333
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:5:p:452-469
Template-Type: ReDIF-Article 1.0
Author-Name: Florian Loos
Author-X-Name-First: Florian
Author-X-Name-Last: Loos
Author-Name: Karl Dvorsky
Author-X-Name-First: Karl
Author-X-Name-Last: Dvorsky
Author-Name: Hans-Dieter Liess
Author-X-Name-First: Hans-Dieter
Author-X-Name-Last: Liess
Title: Determination of temperature in automotive high-voltage cables of finite length with dynamic current profiles
Abstract:
To avoid overheating of essential components and generation of hot spots in modern vehicles, especially hybrid and electrical cars, cables have to be dimensioned correctly. Dynamic current profiles with high peak currents make an adequate dimensioning difficult. We present a new approach to calculate the temperature distribution in current carrying shielded cables under non-constant current loads. The influence of attached materials is respected as well as different environment conditions. The specific modelling equations entail a distinction of cases, depending on the magnitude of current loads. Moreover, simulation and measurement results are compared and show good accordance. Further advantages concerning calculation times and industrial practicability are presented.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 433-451
Issue: 5
Volume: 20
Year: 2014
Month: 9
X-DOI: 10.1080/13873954.2013.833120
File-URL: http://hdl.handle.net/10.1080/13873954.2013.833120
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:5:p:433-451
Template-Type: ReDIF-Article 1.0
Author-Name: Giuseppe Pontrelli
Author-X-Name-First: Giuseppe
Author-X-Name-Last: Pontrelli
Author-Name: Ian Halliday
Author-X-Name-First: Ian
Author-X-Name-Last: Halliday
Author-Name: Simone Melchionna
Author-X-Name-First: Simone
Author-X-Name-Last: Melchionna
Author-Name: Tim J. Spencer
Author-X-Name-First: Tim J.
Author-X-Name-Last: Spencer
Author-Name: Sauro Succi
Author-X-Name-First: Sauro
Author-X-Name-Last: Succi
Title: Lattice Boltzmann method as a computational framework for multiscale haemodynamics
Abstract:
Recent developments of the lattice Boltzmann method for large-scale haemodynamic applications are presented, with special focus on multiscale aspects, including the self-consistent dynamics of suspended biological bodies and their coupling to surface structures, such as the glycocalyx, in the proximity of endothelium using unstructured grids. The description of such multiscale phenomena, each one treated with a suitable variation of the lattice Boltzmann method, opens up new perspectives for a fundamental understanding of the physical mechanisms underlying cardiovascular pathologies, such as plaque growth and the subsequent development of atherosclerotic diseases.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 470-490
Issue: 5
Volume: 20
Year: 2014
Month: 9
X-DOI: 10.1080/13873954.2013.833523
File-URL: http://hdl.handle.net/10.1080/13873954.2013.833523
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:5:p:470-490
Template-Type: ReDIF-Article 1.0
Author-Name: Georgy Kostin
Author-X-Name-First: Georgy
Author-X-Name-Last: Kostin
Author-Name: Vasily Saurin
Author-X-Name-First: Vasily
Author-X-Name-Last: Saurin
Author-Name: Harald Aschemann
Author-X-Name-First: Harald
Author-X-Name-Last: Aschemann
Author-Name: Andreas Rauh
Author-X-Name-First: Andreas
Author-X-Name-Last: Rauh
Title: Integrodifferential approaches to frequency analysis and control design for compressible fluid flow in a pipeline element
Abstract:
In this study, modelling, frequency analysis, and optimization of control processes are considered for the fluid flow in pipeline systems. A mathematical model of controlled pipeline elements with distributed parameters is proposed to describe the dynamical behaviour of compressible fluid which is transported in a long rigid tube. By exploiting specific functions representing cross-sectional forces and effective displacements as well as linear approximations of fluidic resistances, the original problem with non-uniform parameters is reduced to a partial differential equation (PDE) system with constant coefficients and homogeneous initial and boundary conditions. Three numerical approaches are applied to an efficient analysis of natural vibrations and reliable control-oriented modelling of pipeline elements. The conventional Galerkin method is compared with the method of integrodifferential relations based on a weak formulation of the constitutive laws. In the latter approach, the original initial-boundary value problem is reduced to the minimization of an error functional which provides explicit energy estimates of the solution quality. A novel projection approach is implemented on the basis of the Petrov–Galerkin method combined with the method of integrodifferential relations. This technique benefits from the advantages of the above-mentioned projection and variational approaches, namely sufficient numerical stability, a lower differential order, and an explicit quality estimation. Numerical optimization procedures, making use of a modified finite element technique, are proposed to obtain a feedforward control strategy for changing the pressure and mass flow inside the pipeline system to a desired operating state. At this given finite point of time, residual elastic oscillations inside the pipeline are minimized. Numerical results, obtained for ideal as well as viscous fluid models, are analysed and discussed.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 504-527
Issue: 5
Volume: 20
Year: 2014
Month: 9
X-DOI: 10.1080/13873954.2013.842595
File-URL: http://hdl.handle.net/10.1080/13873954.2013.842595
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:5:p:504-527
Template-Type: ReDIF-Article 1.0
Author-Name: A. Sanei
Author-X-Name-First: A.
Author-X-Name-Last: Sanei
Author-Name: A.B. Novinzadeh
Author-X-Name-First: A.B.
Author-X-Name-Last: Novinzadeh
Author-Name: M. Habibi
Author-X-Name-First: M.
Author-X-Name-Last: Habibi
Title: Addition of momentum and kinetic energy effects in supersonic compressible flow using pseudo bond graph approach
Abstract:
In most of the papers published on compressible fluid using pseudo the bond graph approach, momentum and kinetic energy effects have been neglected due to low speed. However, in convergent–divergent nozzles that the flow is supersonic, these models will lose their validation. For the purpose of considering kinetic energy in compressible fluid flow, this paper introduces a new field (KE-field) to pseudo bond graph. This field can also be used to extract the momentum equation on the gaseous models. Furthermore, Karnopp’s suggested relation for an isentropic nozzle is developed to a convergent–divergent nozzle. The simulation results show that the thrust force obtained from the simulations has a very good agreement to analytical relationships. Therefore, it suggests that the KE-field can be used for modelling the thrust force. As bond graph method has been implemented in many software applications such as MS1, SYMBOLS2000 and 20SIM®, the new field can also be used in these software.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 491-503
Issue: 5
Volume: 20
Year: 2014
Month: 9
X-DOI: 10.1080/13873954.2014.885055
File-URL: http://hdl.handle.net/10.1080/13873954.2014.885055
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:5:p:491-503
Template-Type: ReDIF-Article 1.0
Author-Name: G. Stadler
Author-X-Name-First: G.
Author-X-Name-Last: Stadler
Author-Name: A. Steinboeck
Author-X-Name-First: A.
Author-X-Name-Last: Steinboeck
Author-Name: M. Baumgart
Author-X-Name-First: M.
Author-X-Name-Last: Baumgart
Author-Name: A. Ettl
Author-X-Name-First: A.
Author-X-Name-Last: Ettl
Author-Name: A. Kugi
Author-X-Name-First: A.
Author-X-Name-Last: Kugi
Title: Model-based estimation of the stress-strain curve of metal strips
Abstract:
The identification of the stress-strain curve of metal strips is a common task in the metals industry. As an alternative to commonly used tensile test machines, an inexpensive, model-based optical measurement method is presented. Particular importance was placed on the cost and usability of the method. The indirect approach computes the stress-strain curve based on a measured strip bending line. For the measurement, a metal strip is bent over a solid roll. A defined weight can be mounted at the end of the strip to control the local bending moment in the strip. The bending line of the strip is optically measured by a camera. The identification is carried out based on an optimization problem, where the quadratic error between the measured and the modelled strip bending line is minimized. Experimental results and measurements from a tensile test machine show a good agreement and thus verify the proposed identification method.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 224-241
Issue: 3
Volume: 25
Year: 2019
Month: 5
X-DOI: 10.1080/13873954.2019.1604553
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1604553
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:3:p:224-241
Template-Type: ReDIF-Article 1.0
Author-Name: D. Büchl
Author-X-Name-First: D.
Author-X-Name-Last: Büchl
Author-Name: W. Kemmetmüller
Author-X-Name-First: W.
Author-X-Name-Last: Kemmetmüller
Author-Name: T. Glück
Author-X-Name-First: T.
Author-X-Name-Last: Glück
Author-Name: B. Deutschmann
Author-X-Name-First: B.
Author-X-Name-Last: Deutschmann
Author-Name: A. Kugi
Author-X-Name-First: A.
Author-X-Name-Last: Kugi
Title: A dynamic model of power metal-oxide-semiconductor field-effect transistor half-bridges for the fast simulation of switching induced electromagnetic emissions
Abstract:
Hard switching of semiconductors is the main source of conducted electromagnetic emissions (EME) in pulse-width modulation (PWM) driven power inverters. The requirements on the electromagnetic compatibility grow with the increasing number of installed electric motor drives and inductive power converters. An accurate prediction of the conducted EME requires a model which considers the switching transition of the power semiconductors and the parasitic elements. This typically leads to complex SPICE models, which are hardly suitable for fast dynamic simulations and model-based controller design. This paper presents a compact mathematical model of a low voltage half-bridge inverter, which is based on large-signal models for the individual components and allows for the fast simulation of the conducted EME and switching losses. The high accuracy of the proposed mathematical model is demonstrated by measurement results. In particular, it is shown that the model is able to accurately predict the conducted electromagnetic emissions up to 100 MHz.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 242-260
Issue: 3
Volume: 25
Year: 2019
Month: 5
X-DOI: 10.1080/13873954.2019.1610899
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1610899
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:3:p:242-260
Template-Type: ReDIF-Article 1.0
Author-Name: Nabil Vaeli
Author-X-Name-First: Nabil
Author-X-Name-Last: Vaeli
Author-Name: Bizhan Honarvar
Author-X-Name-First: Bizhan
Author-X-Name-Last: Honarvar
Author-Name: Nadia Esfandiari
Author-X-Name-First: Nadia
Author-X-Name-Last: Esfandiari
Author-Name: Zahra Arab Aboosadi
Author-X-Name-First: Zahra
Author-X-Name-Last: Arab Aboosadi
Title: A mathematical modelling to extract active ingredients from Oliveria decumbens by supercritical fluid extraction through using ultrasonic process
Abstract:
The experimental feasibility of extracting carvacrol or cymophenol from local and medicinal Oliveria decumbens by supercritical carbon dioxide through using ultrasound waves was investigated in this study. The extraction modelling was carried out in two forms: Internal and external. The internal model was adopted to simulate the concentration distribution of the phytochemicals in the plant particles. In this model, the extracted cell was assumed to be a filled substrate and two mechanisms of molecular permeability and mass transfer had the greatest effect. The comparison of the experimental data obtained from modelling revealed that both the internal and external models are compatible with the experimental data as much as 80%, indicating an acceptable accuracy. Furthermore, the empirical data is completely in line with the model at the final time (40 min), which is the time to reach the equilibrium.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 261-283
Issue: 3
Volume: 25
Year: 2019
Month: 5
X-DOI: 10.1080/13873954.2019.1620292
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1620292
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:3:p:261-283
Template-Type: ReDIF-Article 1.0
Author-Name: Gilberto Gonzalez Avalos
Author-X-Name-First: Gilberto
Author-X-Name-Last: Gonzalez Avalos
Author-Name: Gerardo Ayala
Author-X-Name-First: Gerardo
Author-X-Name-Last: Ayala
Author-Name: Noe Barrera Gallegos
Author-X-Name-First: Noe
Author-X-Name-Last: Barrera Gallegos
Author-Name: Aaron Padilla Jose
Author-X-Name-First: Aaron Padilla
Author-X-Name-Last: Jose
Title: Linearization of a class of non-linear systems modelled by multibond graphs
Abstract:
Based on non-linear systems described by multibond graphs, a procedure designed to present symbolic linearization of these multibond graphs, is presented in this paper. Firstly, a junction structure of a multibond graph with multiport gyrators that represent Eulerian junction structures is proposed. In addition, non-linear multiport resistors are considered. By knowing the non-linear causal paths and loops of the non-linear multibond graph, the linearization is obtained by two steps: (1) The original multibond graph on the nominal operating point is evaluated; (2) New and additional paths based on the non-linear causal paths and loops are included. The state space representation of the linearized multibond graph using the corresponding junction structure is presented. An advantage of this methodology is its ability to allow the user to define a nominal operating point in which the linearization will be carried out.In order to apply the proposed methodology, two physical systems are modelled and linearized by multibond graphs: a synchronous generator and a two degrees of freedom PUMA. Simulation results of these non-linear and linearized systems are shown.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 284-332
Issue: 3
Volume: 25
Year: 2019
Month: 5
X-DOI: 10.1080/13873954.2019.1621905
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1621905
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:3:p:284-332
Template-Type: ReDIF-Article 1.0
Author-Name: Peter Benner
Author-X-Name-First: Peter
Author-X-Name-Last: Benner
Author-Name: Patrick Kürschner
Author-X-Name-First: Patrick
Author-X-Name-Last: Kürschner
Author-Name: Jens Saak
Author-X-Name-First: Jens
Author-X-Name-Last: Saak
Title: An improved numerical method for balanced truncation for symmetric second-order systems
Abstract:
We consider balanced truncation model order reduction for symmetric second-order systems. The occurring large-scale generalized and structured Lyapunov equations are solved with a specially adapted low-rank alternating directions implicit (ADI) type method. Stopping criteria for this iteration are investigated, and a new result concerning the Lyapunov residual within the low-rank ADI method is established. We also propose a goal-oriented stopping criterion which tries to incorporate the balanced truncation approach already during the ADI iteration. The model reduction approach using the ADI method with different stopping criteria is evaluated on several test systems.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 593-615
Issue: 6
Volume: 19
Year: 2013
Month: 12
X-DOI: 10.1080/13873954.2013.794363
File-URL: http://hdl.handle.net/10.1080/13873954.2013.794363
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:6:p:593-615
Template-Type: ReDIF-Article 1.0
Author-Name: Christoph Hametner
Author-X-Name-First: Christoph
Author-X-Name-Last: Hametner
Author-Name: Markus Stadlbauer
Author-X-Name-First: Markus
Author-X-Name-Last: Stadlbauer
Author-Name: Maxime Deregnaucourt
Author-X-Name-First: Maxime
Author-X-Name-Last: Deregnaucourt
Author-Name: Stefan Jakubek
Author-X-Name-First: Stefan
Author-X-Name-Last: Jakubek
Title: Incremental optimal process excitation for online system identification based on evolving local model networks
Abstract:
In this paper, a methodology for the generation of optimal input signals for incremental data-based modelling of nonlinear static and dynamic systems is presented. For this purpose, an online strategy consisting of an evolving model and an iterative finite horizon input optimization in parallel to the ongoing experiment is pursued. Such an integrated methodology is methodically very efficient since the experiment is only conducted until the desired model quality is obtained. For the process excitation, the compliance with system input and output limits is of great importance. Especially for nonlinear dynamic systems, the compliance with output constraints is challenging since the current input has an impact on all forthcoming outputs. The generation of optimal inputs is based on the iterative optimization of the Fisher information matrix of the current process model subject to input and output constraints. For the identification, an evolving local model network is used that can cope with a growing amount of data. To this end, the parameter adaptation and the automated structure evolution are characteristic of the evolving local model network. The effectiveness of the proposed method is demonstrated on two typical automotive application examples. First, a stationary smoke model of a diesel engine and second, a dynamic exhaust temperature model are identified by use of optimal process excitation.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 505-525
Issue: 6
Volume: 19
Year: 2013
Month: 12
X-DOI: 10.1080/13873954.2013.800122
File-URL: http://hdl.handle.net/10.1080/13873954.2013.800122
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:6:p:505-525
Template-Type: ReDIF-Article 1.0
Author-Name: Jia Wang
Author-X-Name-First: Jia
Author-X-Name-Last: Wang
Author-Name: Hong-Wei Wang
Author-X-Name-First: Hong-Wei
Author-X-Name-Last: Wang
Author-Name: Hong Gu
Author-X-Name-First: Hong
Author-X-Name-Last: Gu
Title: A novel recursive subspace identification approach of closed-loop systems
Abstract:
In this paper, a subspace model identification method under closed-loop experimental condition is presented which can be implemented to recursively identify and update the system model. The projected matrices play an important role in this identification scheme which can be obtained by the projection of the input and output data onto the space of exogenous inputs and recursively updated through sliding window technique. The propagator type method in array signal processing is then applied to calculate the subspace spanned by the column vectors of the extended observability matrix without singular value decomposition. The speed of convergence of the proposed method is mainly dependent on the number of block Hankel matrix rows and the initialization accuracy of the projected data matrices. The proposed method is feasible for the closed-loop system contaminated with coloured noises. Two numerical examples show the effectiveness of the proposed algorithm.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 526-539
Issue: 6
Volume: 19
Year: 2013
Month: 12
X-DOI: 10.1080/13873954.2013.801355
File-URL: http://hdl.handle.net/10.1080/13873954.2013.801355
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:6:p:526-539
Template-Type: ReDIF-Article 1.0
Author-Name: Conceição Rocha
Author-X-Name-First: Conceição
Author-X-Name-Last: Rocha
Author-Name: Teresa Mendonça
Author-X-Name-First: Teresa
Author-X-Name-Last: Mendonça
Author-Name: Maria Eduarda Silva
Author-X-Name-First: Maria
Author-X-Name-Last: Eduarda Silva
Title: Modelling neuromuscular blockade: a stochastic approach based on clinical data
Abstract:
During surgical interventions, a muscle relaxant drug is frequently administered with the objective of inducing muscle paralysis. Clinical environment and patient safety issues lead to a huge variety of situations that must be taken into account requiring intensive simulation studies. Hence, population models are crucial for research and development in this field.This work develops a stochastic population model for the neuromuscular blockade (NMB) (muscle paralysis) level induced by atracurium based on a deterministic individual model already proposed in the literature. To achieve this goal, a joint Lognormal distribution is considered for the patient-dependent parameters. This study is based on clinical data collected during general anaesthesia. The procedure developed enables to construct a reliable reference bank of parametrized models that not only reproduces the overall features of the NMB, but also the inter-individual variability characteristic of physiological signals. It turns out that this bank constitutes a fundamental tool to support research on identification and control algorithms and is suitable to be integrated in clinical decision support systems.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 540-556
Issue: 6
Volume: 19
Year: 2013
Month: 12
X-DOI: 10.1080/13873954.2013.801865
File-URL: http://hdl.handle.net/10.1080/13873954.2013.801865
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:6:p:540-556
Template-Type: ReDIF-Article 1.0
Author-Name: Kelly Spendlove
Author-X-Name-First: Kelly
Author-X-Name-Last: Spendlove
Author-Name: Jesse Berwald
Author-X-Name-First: Jesse
Author-X-Name-Last: Berwald
Author-Name: Tomáš Gedeon
Author-X-Name-First: Tomáš
Author-X-Name-Last: Gedeon
Title: Predicting high-codimension critical transitions in dynamical systems using active learning
Abstract:
Complex dynamical systems, from those appearing in physiology and ecology to Earth system modelling, often experience critical transitions in their behaviour due to potentially minute changes in their parameters. While the focus of much recent work, predicting such bifurcations is still notoriously difficult. We propose an active learning approach to the classification of parameter space of dynamical systems for which the codimension of bifurcations is high. Using elementary notions regarding the dynamics, in combination with the nearest-neighbour algorithm and Conley index theory to classify the dynamics at a predefined scale, we are able to predict with high accuracy the boundaries between regions in parameter space that produce critical transitions.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 557-574
Issue: 6
Volume: 19
Year: 2013
Month: 12
X-DOI: 10.1080/13873954.2013.801866
File-URL: http://hdl.handle.net/10.1080/13873954.2013.801866
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:6:p:557-574
Template-Type: ReDIF-Article 1.0
Author-Name: Xiao-Long Wang
Author-X-Name-First: Xiao-Long
Author-X-Name-Last: Wang
Author-Name: Yao-Lin Jiang
Author-X-Name-First: Yao-Lin
Author-X-Name-Last: Jiang
Title: Two-sided projection methods for model reduction of MIMO bilinear systems
Abstract:
Two-sided projection methods are presented for model reduction of large scale multi-input multi-output bilinear systems. By properly choosing projection matrices, the reduced model possesses a superior moment matching property and we prove it from a new perspective by means of linear equations. The preservation of stability for reduced models is also considered. In contrast to the most existing approaches, we construct the reduced model directly instead of using an iterative procedure, thereby saving much computational cost. As two-sided methods are more likely to produce badly ill-conditioned system matrices, a mixed algorithm having the benefits of one-sided and two-sided methods is proposed at the cost of roughly doubling the dimension of reduced models. Theoretical analysis and numerical experiments show the efficiency of our approach.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 575-592
Issue: 6
Volume: 19
Year: 2013
Month: 12
X-DOI: 10.1080/13873954.2013.805145
File-URL: http://hdl.handle.net/10.1080/13873954.2013.805145
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:6:p:575-592
Template-Type: ReDIF-Article 1.0
Author-Name: The Editors
Title: Editorial Board
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: ebi-ebi
Issue: 6
Volume: 19
Year: 2013
Month: 12
X-DOI: 10.1080/13873954.2013.872821
File-URL: http://hdl.handle.net/10.1080/13873954.2013.872821
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:6:p:ebi-ebi
Template-Type: ReDIF-Article 1.0
Author-Name: C. C. Magruder
Author-X-Name-First: C. C.
Author-X-Name-Last: Magruder
Author-Name: S. Gugercin
Author-X-Name-First: S.
Author-X-Name-Last: Gugercin
Author-Name: C. A. Beattie
Author-X-Name-First: C. A.
Author-X-Name-Last: Beattie
Title: Linear time-periodic dynamical systems: an H2 analysis and a model reduction framework
Abstract:
Linear time-periodic (LTP) dynamical systems frequently appear in the modelling of phenomena related to fluid dynamics, electronic circuits and structural mechanics via linearization centred around known periodic orbits of nonlinear models. Such LTP systems can reach orders that make repeated simulation or other necessary analysis prohibitive, motivating the need for model reduction. We develop here an algorithmic framework for constructing reduced models that retains the LTP structure of the original LTP system. Our approach generalizes optimal approaches that have been established previously for linear time-invariant (LTI) model reduction problems. We employ an extension of the usual H2 Hardy space defined for the LTI setting to time-periodic systems and within this broader framework develop an a posteriori error bound expressible in terms of related LTI systems. Optimization of this bound motivates our algorithm. We illustrate the success of our method on three numerical examples.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 119-142
Issue: 2
Volume: 24
Year: 2018
Month: 3
X-DOI: 10.1080/13873954.2017.1382538
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1382538
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:2:p:119-142
Template-Type: ReDIF-Article 1.0
Author-Name: James R. Phillips
Author-X-Name-First: James R.
Author-X-Name-Last: Phillips
Author-Name: Farid Amirouche
Author-X-Name-First: Farid
Author-X-Name-Last: Amirouche
Title: A momentum form of Kane’s equations for scleronomic systems
Abstract:
Kane’s dynamical equations are an efficient and widely used method for deriving the equations of motion for multibody systems. Despite their popularity, no publication has appeared which adapts them for use with port-based modelling tools such as bond graphs, linear graphs or port-Hamiltonian theory. In this paper, we present – for scleronomic systems – a momentum form of Kane’s equations, fully compatible with port-based modelling methods. When applied to holonomic systems using coordinate derivatives, the momentum form of Kane’s equations is an efficient alternative to Lagrange’s equations, providing a momentum formulation without the need to assemble and differentiate the system kinetic co-energy function. When applied to holonomic or nonholonomic systems using generalized speeds, a rotational decomposition of the generalized forces leads to a convenient set of matrix equations of motion, for which a system-level multibond graph interpretation is given. Heuristics are provided for selection of generalized speeds which, for systems with open-chain kinematics, produce a block-diagonal mass matrix and reduce the complexity of the equations from order-$${N^3}$$N3
to order-$$N$$N
. For scleronomic systems, the momentum formulation retains all analysis capabilities offered by the original acceleration formulation. Two example problems are solved with the momentum formulation, including the nonholonomic rolling thin disk.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 143-169
Issue: 2
Volume: 24
Year: 2018
Month: 3
X-DOI: 10.1080/13873954.2017.1385638
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1385638
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:2:p:143-169
Template-Type: ReDIF-Article 1.0
Author-Name: Wenyou Jia
Author-X-Name-First: Wenyou
Author-X-Name-Last: Jia
Author-Name: Hao Chen
Author-X-Name-First: Hao
Author-X-Name-Last: Chen
Author-Name: Li Liu
Author-X-Name-First: Li
Author-X-Name-Last: Liu
Author-Name: You Li
Author-X-Name-First: You
Author-X-Name-Last: Li
Title: Minimizing total earliness and tardiness on re-entrant batch processing machine with time windows
Abstract:
The time window (TW) generalizes the concept of due date. The semiconductor wafer fabrication system is currently one of the most complex production processes, which has typical re-entrant batch processing machine (RBPM). RBPM is a bottleneck. This paper addresses a scheduling of RBPM with job-dependent TWs. According to a general modelling, an improved and new job-family-oriented modelling of the decomposition method that is based on the slack mixed integer linear programming is proposed. First, the complicated scheduling problem of RBPM is divided into sub-problems, which are executed circularly. Then, each one consists of updating, sequencing and dispatching. The objective is to minimize the total earliness and tardiness for job-dependent TWs. In order to evaluate the proposed modelling, the experiments are implemented on the real-time scheduling simulation platform and optimization toolkit ILOG CPLEX. The results show that the improved modelling obtains better solutions in less computation time.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 170-181
Issue: 2
Volume: 24
Year: 2018
Month: 3
X-DOI: 10.1080/13873954.2017.1394327
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1394327
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:2:p:170-181
Template-Type: ReDIF-Article 1.0
Author-Name: S.-J. Kimmerle
Author-X-Name-First: S.-J.
Author-X-Name-Last: Kimmerle
Author-Name: M. Gerdts
Author-X-Name-First: M.
Author-X-Name-Last: Gerdts
Author-Name: R. Herzog
Author-X-Name-First: R.
Author-X-Name-Last: Herzog
Title: Optimal control of an elastic crane-trolley-load system - a case study for optimal control of coupled ODE-PDE systems
Abstract:
We present a mathematical model of a crane-trolley-load model, where the crane beam is subject to the partial differential equation (PDE) of static linear elasticity and the motion of the load is described by the dynamics of a pendulum that is fixed to a trolley moving along the crane beam. The resulting problem serves as a case study for optimal control of fully coupled partial and ordinary differential equations (ODEs). This particular type of coupled systems arises from many applications involving mechanical multi-body systems. We motivate the coupled ODE-PDE model, show its analytical well-posedness locally in time and examine the corresponding optimal control problem numerically by means of a projected gradient method with Broyden-Fletcher-Goldfarb-Shanno (BFGS) update.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 182-206
Issue: 2
Volume: 24
Year: 2018
Month: 3
X-DOI: 10.1080/13873954.2017.1405046
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1405046
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:2:p:182-206
Template-Type: ReDIF-Article 1.0
Author-Name: A. C. Antoulas
Author-X-Name-First: A. C.
Author-X-Name-Last: Antoulas
Author-Name: Peter Benner
Author-X-Name-First: Peter
Author-X-Name-Last: Benner
Author-Name: Lihong Feng
Author-X-Name-First: Lihong
Author-X-Name-Last: Feng
Title: Model reduction by iterative error system approximation
Abstract:
The analysis of a posteriori error estimates used in reduced basis methods leads to a model reduction scheme for linear time-invariant systems involving the iterative approximation of the associated error systems. The scheme can be used to improve reduced-order models (ROMs) with initial poor approximation quality at a computational cost proportional to that for computing the original ROM. We also show that the iterative approximation scheme is applicable to parametric systems and demonstrate its performance using illustrative examples.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 103-118
Issue: 2
Volume: 24
Year: 2018
Month: 3
X-DOI: 10.1080/13873954.2018.1427116
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1427116
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:2:p:103-118
Template-Type: ReDIF-Article 1.0
Author-Name: Carlo Bianca
Author-X-Name-First: Carlo
Author-X-Name-Last: Bianca
Author-Name: Caterina Mogno
Author-X-Name-First: Caterina
Author-X-Name-Last: Mogno
Title: Modelling pedestrian dynamics into a metro station by thermostatted kinetic theory methods
Abstract:
This paper deals with the modelling of pedestrian dynamics at the entry of a metro station by means of the thermostatted kinetic theory framework. Specifically, the model depicts the time evolution of the pedestrian dynamics at the turnstiles under no panic conditions. The modelling of the microscopic interactions is based on the stochastic game theory and reflects the decision dynamics of the turnstiles pursued by pedestrians. A qualitative analysis is addressed to the equilibrium solutions by means of the classical stability theory of perturbations. Numerical simulations aim at showing the emerging behaviours captured by the model. In particular the model validation is obtained by performing a sensitivity analysis on the parameters and on the initial conditions. Further refinements and research perspective, including the modelling under panic conditions, are discussed in the last section of the paper.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 207-235
Issue: 2
Volume: 24
Year: 2018
Month: 3
X-DOI: 10.1080/13873954.2018.1432664
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1432664
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:2:p:207-235
Template-Type: ReDIF-Article 1.0
Author-Name: Wojciech Sochacki
Author-X-Name-First: Wojciech
Author-X-Name-Last: Sochacki
Title: Modelling and analysis of damped vibration in hydraulic cylinder
Abstract:
The study presents a formulation on the basis of Hamilton’s principle and solution for the problem of damped vibration in hydraulic cylinders. The physical model took into consideration the energy dissipation in a vibrating cylinder as a result of external viscous damping and internal damping of viscoelastic material in beams used to construct a model of a cylinder (rheological model by Kelvin–Voigt). Constructional damping in the points of the cylinder connection with the components of the basic structure was also considered. The example computation was made for a cylinder used in a mining prop. The results of the computations concern the determination of the relationships between the first eigenvalue of transverse vibration in the cylinder and its extension length with two values of load and determination of the amplitude decay factor for the first and the second eigenvalue versus the extension length. Furthermore, the study also focused on determination of the relationships between the amplitude decay factor of the first and second mode of vibration for a particular length of the cylinder.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 23-37
Issue: 1
Volume: 21
Year: 2015
Month: 1
X-DOI: 10.1080/13873954.2013.871564
File-URL: http://hdl.handle.net/10.1080/13873954.2013.871564
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:1:p:23-37
Template-Type: ReDIF-Article 1.0
Author-Name: Gilberto Gonzalez Avalos
Author-X-Name-First: Gilberto
Author-X-Name-Last: Gonzalez Avalos
Author-Name: Rene Galindo Orozco
Author-X-Name-First: Rene
Author-X-Name-Last: Galindo Orozco
Title: A procedure to linearize a class of non-linear systems modelled by bond graphs
Abstract:
A procedure is proposed to obtain the linearization of a class of non-linear physical systems using bond graphs. Also, a junction structure of a non-linear bond graph considering linearly dependent and independent state variables is described. From the junction structure of the non-linear bond graph a procedure to build a linearized bond graph is presented. Finally, an example of a Programmable Universal Manipulation Arm (PUMA) manipulator is given.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 38-57
Issue: 1
Volume: 21
Year: 2015
Month: 1
X-DOI: 10.1080/13873954.2013.874360
File-URL: http://hdl.handle.net/10.1080/13873954.2013.874360
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:1:p:38-57
Template-Type: ReDIF-Article 1.0
Author-Name: Maxime Deregnaucourt
Author-X-Name-First: Maxime
Author-X-Name-Last: Deregnaucourt
Author-Name: Markus Stadlbauer
Author-X-Name-First: Markus
Author-X-Name-Last: Stadlbauer
Author-Name: Christoph Hametner
Author-X-Name-First: Christoph
Author-X-Name-Last: Hametner
Author-Name: Stefan Jakubek
Author-X-Name-First: Stefan
Author-X-Name-Last: Jakubek
Author-Name: Hans-Michael Koegeler
Author-X-Name-First: Hans-Michael
Author-X-Name-Last: Koegeler
Title: Evolving model architecture for custom output range exploration
Abstract:
In this paper, a methodology for combined online design of experiments and system identification is presented. More specifically, the paper addresses the problem of creating a model automatically that describes an unknown process accurately in a predefined range of its output. Such a model is typically needed for the calibration of combustion engines where only a relatively small emission range is of interest. The presented solution approach consists of two interacting components: first, an evolving local model network is used for creating, refining and extending a data-driven model, based on the incoming measurements; second, model-based approaches are proposed for designing new experiments so that the data-driven model has a high degree of accuracy in a predefined range of its output. The method uses, besides the models, a space-filling to explore untrained areas. The proposed concepts are illustrated and discussed by means of an academic and two real-world examples.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 1-22
Issue: 1
Volume: 21
Year: 2015
Month: 1
X-DOI: 10.1080/13873954.2014.885056
File-URL: http://hdl.handle.net/10.1080/13873954.2014.885056
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:1:p:1-22
Template-Type: ReDIF-Article 1.0
Author-Name: Murat Emre Kartal
Author-X-Name-First: Murat Emre
Author-X-Name-Last: Kartal
Author-Name: Alemdar Bayraktar
Author-X-Name-First: Alemdar
Author-X-Name-Last: Bayraktar
Title: Non-linear response of the rockfill in a concrete-faced rockfill dam under seismic excitation
Abstract:
This study investigates the non-linear response of the rockfill in a concrete-faced rockfill dam under seismic excitation for various concrete slab thicknesses from 30 to 100 cm thick. The effect of the friction in the concrete slab rockfill interface on the non-linear response of the rockfill is also considered in the numerical solutions. The friction contact in the concrete slab joints is provided with contact elements based on the Coulomb’s friction law. The hydrodynamic pressure of the reservoir water is considered by the fluid finite elements based on the Lagrangian approach. Geometrical and material non-linear behaviours of the dam-foundation-reservoir interaction system are considered together in the finite element analyses. The Drucker–Prager model is used to obtain materially non-linear behaviour of the concrete slab. The multi linear kinematic hardening model is used for rockfill and foundation rock in the material non-linear analyses. Therefore, the uniaxial stress–strain relations of the rockfill and foundation rock are determined from the shear stress–shear strain relations of the gravel and rock, respectively. The principle compressive and tensile stresses of the rockfill are investigated along the horizontal section of the rockfill. According to numerical analyses, the most critical stresses occur in the upstream and downstream faces of the dam for the concrete slab thickness of 30 cm, while the optimum thickness for seismic performance is 58 cm.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 77-101
Issue: 1
Volume: 21
Year: 2015
Month: 1
X-DOI: 10.1080/13873954.2014.898157
File-URL: http://hdl.handle.net/10.1080/13873954.2014.898157
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:1:p:77-101
Template-Type: ReDIF-Article 1.0
Author-Name: Fusheng Wang
Author-X-Name-First: Fusheng
Author-X-Name-Last: Wang
Author-Name: Shihui Huo
Author-X-Name-First: Shihui
Author-X-Name-Last: Huo
Author-Name: Shengjun Qiao
Author-X-Name-First: Shengjun
Author-X-Name-Last: Qiao
Author-Name: Junran Zhang
Author-X-Name-First: Junran
Author-X-Name-Last: Zhang
Author-Name: Zhufeng Yue
Author-X-Name-First: Zhufeng
Author-X-Name-Last: Yue
Title: An effective computer modelling approach to the study of aeroelastic characteristics of an aircraft composite wing with high aspect ratio
Abstract:
Static aeroelastic and flutter characteristics of an aircraft composite wing with high aspect ratio were analysed by an effective Computational Fluid Dynamics and Computational Structure Dynamics coupled method. Effects of stiffness distribution on aeroelastic characteristics were considered. Honeycomb core sandwich composite was considered to be equivalent to an orthotropic material by stiffness and inertance equivalent method to allow highly efficient numerical simulation, which was used for analysis of bending and torsional stiffness distribution. The results showed that the redistributed aerodynamic load leads to a decrease of pressure difference between the upper and lower airfoils. The flutter speed of the composite wing is near 0.64 Ma. Both bending and torsional stiffness increases with a small increase of beam size. Stiffness of the wing root has a major influence generally on the static aeroelastic characteristics. Both the lift coefficient and the loss percent decrease with a small increase of beam size. Effects of stiffness distribution on frequency are not obvious. Flutter speed remains close to the initial value when the beam size is changed.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 58-76
Issue: 1
Volume: 21
Year: 2015
Month: 1
X-DOI: 10.1080/13873954.2014.903283
File-URL: http://hdl.handle.net/10.1080/13873954.2014.903283
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:1:p:58-76
Template-Type: ReDIF-Article 1.0
Author-Name: Dominik Schindele
Author-X-Name-First: Dominik
Author-X-Name-Last: Schindele
Author-Name: Harald Aschemann
Author-X-Name-First: Harald
Author-X-Name-Last: Aschemann
Author-Name: Robert Prabel
Author-X-Name-First: Robert
Author-X-Name-Last: Prabel
Title: Nonlinear model-predictive control with hysteresis compensation of an electro-pneumatic clutch for truck applications
Abstract:
This contribution presents two real-time capable nonlinear model-predictive control (NMPC) approaches for an electro-pneumatic clutch for heavy trucks: a centralized control approach and a cascaded one. A clutch is necessary at start-up or during gear shifts to connect or disconnect the combustion engine and the gear box. This automated actuator disburdens the driver and provides the necessary actuation force according to the large torque typically transmitted through the drive train. The force characteristic of the clutch, however, is subject to hysteresis, which is described by a generalized Bouc–Wen model and used for a feedforward hysteresis compensation in the control algorithm. The proposed NMPC-algorithm involves (i) a minimization of the difference between the desired and predicted state vector at the end of the prediction horizon and (ii) flatness-based techniques to compute desired trajectories for the complete state vector as well as the control input. The optimal control is given by an additional, minimum-norm control input that minimizes the difference between the predicted state vector and the desired one at the end of the prediction horizon. Thereby, the computation effort of the NMPC approaches can be kept relatively small, and a real-time evaluation becomes possible. A reduced-order observer estimates an effective pressure in the clutch that also accounts for an uncertain disturbance force. Thereby, a disturbance compensation and a high tracking accuracy is achievable for the piston position as controlled variable. The efficiency of the two proposed control structures is emphasized by experimental results from a dedicated test rig.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 105-129
Issue: 2
Volume: 20
Year: 2014
Month: 3
X-DOI: 10.1080/13873954.2013.812970
File-URL: http://hdl.handle.net/10.1080/13873954.2013.812970
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:2:p:105-129
Template-Type: ReDIF-Article 1.0
Author-Name: Tina Sentočnik
Author-X-Name-First: Tina
Author-X-Name-Last: Sentočnik
Author-Name: Maja Atanasijević-Kunc
Author-X-Name-First: Maja
Author-X-Name-Last: Atanasijević-Kunc
Author-Name: Jože Drinovec
Author-X-Name-First: Jože
Author-X-Name-Last: Drinovec
Author-Name: Marija Pfeifer
Author-X-Name-First: Marija
Author-X-Name-Last: Pfeifer
Title: Efficacy analysis of a body-mass-reduction treatment using mathematical modelling
Abstract:
Obesity was categorized as a chronic disease by the World Health Organization (WHO) in 1997 because the problem had reached at pandemic level and presented a serious risk factor with respect to people who have been developing type-2 diabetes, hyperdyslipidaemia and hypertension. These four risk factors tend to accelerate the development of cardiovascular diseases. As a result, obesity has also become a significant social and economic burden. An important observation with regard to the population exhibiting increased body mass is the fact that they would like to decrease their weight, although they are frequently not successful. In this paper, a modelling-and-simulation approach is used for the presentation, analysis and explanation of the reasons that have an important influence on the treatment’s efficacy. The presented modelling results are based on the observation and treatment experiences of patients in a specialized institution over a period of 15 years, where each year around 100 new patients enter the treatment programme. The introduction of the motivation principle in the model structure allows strong support for the actions of the therapeutic team in a closed-loop manner, as the checking of different scenarios for the individual patient is easily realized. The efficacy of the treatment can, in this way, be significantly improved. In the past 6 years, which mainly involved open-loop treatments, the dropout rate was 70%. After the introduction of proposed closed-loop approach, this was reduced to 27% in the past year. As a consequence, the effect on body-mass control was significantly improved.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 146-169
Issue: 2
Volume: 20
Year: 2014
Month: 3
X-DOI: 10.1080/13873954.2013.814680
File-URL: http://hdl.handle.net/10.1080/13873954.2013.814680
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:2:p:146-169
Template-Type: ReDIF-Article 1.0
Author-Name: Oscar Acuña
Author-X-Name-First: Oscar
Author-X-Name-Last: Acuña
Author-Name: Carla Martin-Villalba
Author-X-Name-First: Carla
Author-X-Name-Last: Martin-Villalba
Author-Name: Alfonso Urquia
Author-X-Name-First: Alfonso
Author-X-Name-Last: Urquia
Title: Virtual lab in Modelica of a cement clinker cooler for operator training
Abstract:
Plant operator training plays a fundamental role in improving the energy efficiency of the cement manufacturing process and in reducing the CO2 emission. A virtual lab of a clinker grate cooler, intended for the training of cement plant operators, has been developed. The grate cooler model has been derived from first principles, and has been validated by consulting cement industry experts, and comparing the simulated results with published data and available information from the cement industry. The model has been described in the Modelica language. The Interactive Modelica library has been used to develop the interactive user-to-model interface, and the communication between this interface and the model. The virtual lab, which is completely described in Modelica, has been simulated using the Dymola 6.1 modelling environment. The Interactive Modelica library can be freely downloaded from the website http://www.euclides.dia.uned.es/
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 170-193
Issue: 2
Volume: 20
Year: 2014
Month: 3
X-DOI: 10.1080/13873954.2013.819019
File-URL: http://hdl.handle.net/10.1080/13873954.2013.819019
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:2:p:170-193
Template-Type: ReDIF-Article 1.0
Author-Name: Hatem Oueslati
Author-X-Name-First: Hatem
Author-X-Name-Last: Oueslati
Author-Name: Salah Ben Mabrouk
Author-X-Name-First: Salah Ben
Author-X-Name-Last: Mabrouk
Author-Name: Abdelkader Mami
Author-X-Name-First: Abdelkader
Author-X-Name-Last: Mami
Title: Dynamic modelling and performance study of solar gas tunnel dryer
Abstract:
The work presented in this article focuses on the analysis and modelling of heat and mass transfers in the tunnel dryer during the drying of agricultural products. The main objective of this work is to establish a global modelling of the studied system based on the bond graph methodology. The pseudo-bond graph methodology was used in modelling the system. Such methodology was very suitable for this thermal process since it allows good management of the nonlinearity present in the system.The thermal performance of the proposed dryer is analysed by solving the various energy balance equations. An application of drying tomatoes was achieved and a fair agreement was observed between predicted and experimental results.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 130-145
Issue: 2
Volume: 20
Year: 2014
Month: 3
X-DOI: 10.1080/13873954.2013.819020
File-URL: http://hdl.handle.net/10.1080/13873954.2013.819020
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:2:p:130-145
Template-Type: ReDIF-Article 1.0
Author-Name: S. Grosswindhager
Author-X-Name-First: S.
Author-X-Name-Last: Grosswindhager
Author-Name: L. Haffner
Author-X-Name-First: L.
Author-X-Name-Last: Haffner
Author-Name: A. Voigt
Author-X-Name-First: A.
Author-X-Name-Last: Voigt
Author-Name: M. Kozek
Author-X-Name-First: M.
Author-X-Name-Last: Kozek
Title: Fuzzy modelling of a moving grate biomass furnace for simulation and control purposes
Abstract:
Takagi–Sugeno (TS) fuzzy models are developed for a moving grate biomass furnace for the purpose of simulating and predicting the main process output variables, which are heat output, oxygen concentration of flue gas, and temperature of flue gas. Numerous approaches to modelling biomass furnaces have been proposed in the literature. Usually their objective is to simulate the furnace as accurately as possible. Hence, very complex model architectures are utilized which are not suited for applications like model predictive control. TS fuzzy models are able to approximate the global non-linear behaviour of a moving grate biomass furnace by interpolating between local linear, time-invariant models. The fuzzy partitions of the individual TS fuzzy models are constructed by an axis-orthogonal, incremental partitioning scheme. Validation results with measured process data demonstrate the excellent performance of the developed fuzzy models.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 194-208
Issue: 2
Volume: 20
Year: 2014
Month: 3
X-DOI: 10.1080/13873954.2013.821495
File-URL: http://hdl.handle.net/10.1080/13873954.2013.821495
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:2:p:194-208
Template-Type: ReDIF-Article 1.0
Author-Name: M. Geuss
Author-X-Name-First: M.
Author-X-Name-Last: Geuss
Author-Name: B. Lohmann
Author-X-Name-First: B.
Author-X-Name-Last: Lohmann
Title: STABLE – a stability algorithm for parametric model reduction by matrix interpolation
Abstract:
In this article, an algorithm guaranteeing asymptotic stability for parametric model order reduction by matrix interpolation is proposed for the general class of high-dimensional linear time-invariant systems. In the first step, the system matrices of the high-dimensional parameter-dependent system are computed for a set of parameter vectors. The local high-order systems are reduced by a projection-based reduction method and stabilized, if necessary. Secondly, the low-order systems are transformed into a consistent set of generalized coordinates. Thirdly, a new procedure using semidefinite programming is applied to the low-order systems, converting them into strictly dissipative form. Finally, an asymptotically stable reduced order model can be calculated for any new parameter vector of interest by interpolating the system matrices of the local low-order models. We show that this approach works without any limiting conditions concerning the structure of the large-scale model and is suitable for real-time applications. The method is illustrated by two numerical examples.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 307-322
Issue: 4
Volume: 22
Year: 2016
Month: 7
X-DOI: 10.1080/13873954.2016.1198383
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1198383
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:4:p:307-322
Template-Type: ReDIF-Article 1.0
Author-Name: M. Redeker
Author-X-Name-First: M.
Author-X-Name-Last: Redeker
Author-Name: B. Haasdonk
Author-X-Name-First: B.
Author-X-Name-Last: Haasdonk
Title: A POD–EIM reduced two-scale model for precipitation in porous media
Abstract:
A time-dependent two-scale multiphase model for precipitation in porous media is considered, which has recently been proposed and investigated numerically. For numerical treatment, the microscale model needs to be finely resolved due to moving discontinuities modelled by several phase-field functions. This results in high computational demands due to the need of resolving many such highly resolved cell problems in course of the two-scale simulation. In this article, we present a model order reduction technique for this model, which combines different ingredients such as proper orthogonal decomposition for construction of the approximating spaces, the empirical interpolation method for parameter dependency and multiple basis sets for treating the high solution variability. The resulting reduced model experimentally demonstrates considerable acceleration and good accuracy both in reproduction as well as generalization experiments.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 323-344
Issue: 4
Volume: 22
Year: 2016
Month: 7
X-DOI: 10.1080/13873954.2016.1198384
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1198384
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:4:p:323-344
Template-Type: ReDIF-Article 1.0
Author-Name: Jörg Fehr
Author-X-Name-First: Jörg
Author-X-Name-Last: Fehr
Author-Name: Philip Holzwarth
Author-X-Name-First: Philip
Author-X-Name-Last: Holzwarth
Author-Name: Peter Eberhard
Author-X-Name-First: Peter
Author-X-Name-Last: Eberhard
Title: Interface and model reduction for efficient explicit simulations - a case study with nonlinear vehicle crash models
Abstract:
This work presents an approach to save simulation time in explicit crash simulations of vehicles by applying model order reduction (MOR). The model of a kart frame is split into linear and nonlinear parts. The linear part is reduced with linear MOR techniques in MatMorembs. Optimal substructuring methods are used to calculate suitable reduced models which are exported to LS-DYNA. Afterwards, the model consisting of a linear reduced part and a nonlinear part is simulated in the online step. The plastic deformation of the kart frame as well as the accelerations of the driver calculated with various reduction and parameter settings are compared with the accelerations measured when the original, unreduced nonlinear model is simulated. For optimal simulation results, the large interface between the models needs to be approximated by suitable interface-reduction approaches. The novel contribution is the application of advanced interface-reduction techniques in nonlinear explicit crash simulations. Craig–Bampton and Gramian matrix-based-like techniques with global, local and no interface reduction are compared to find optimally reduced substructures in terms of approximation quality of the assembled system and computational effort. For the kart frame, the applicability of the method is proven by gaining a small simulation speed up which cannot be achieved with the standard reduction methods provided by LS-DYNA.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 380-396
Issue: 4
Volume: 22
Year: 2016
Month: 7
X-DOI: 10.1080/13873954.2016.1198385
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1198385
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:4:p:380-396
Template-Type: ReDIF-Article 1.0
Author-Name: N. Lang
Author-X-Name-First: N.
Author-X-Name-Last: Lang
Author-Name: J. Saak
Author-X-Name-First: J.
Author-X-Name-Last: Saak
Author-Name: T. Stykel
Author-X-Name-First: T.
Author-X-Name-Last: Stykel
Title: Balanced truncation model reduction for linear time-varying systems
Abstract:
A practical procedure based on implicit time integration methods applied to the differential Lyapunov equations arising in the square root balanced truncation method is presented. The application of high-order time integrators results in indefinite right-hand sides of the algebraic Lyapunov equations that have to be solved within every time step. Therefore, classical methods exploiting the inherent low-rank structure often observed for practical applications end up in complex data and arithmetic. Avoiding the additional effort in treating complex quantities, a symmetric indefinite factorization of both the right-hand side and the solution of the differential Lyapunov equations is applied.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 267-281
Issue: 4
Volume: 22
Year: 2016
Month: 7
X-DOI: 10.1080/13873954.2016.1198386
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1198386
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:4:p:267-281
Template-Type: ReDIF-Article 1.0
Author-Name: L. Iapichino
Author-X-Name-First: L.
Author-X-Name-Last: Iapichino
Author-Name: S. Volkwein
Author-X-Name-First: S.
Author-X-Name-Last: Volkwein
Author-Name: A. Wesche
Author-X-Name-First: A.
Author-X-Name-Last: Wesche
Title: A-posteriori error analysis for lithium-ion concentrations in batteries utilizing the reduced-basis method
Abstract:
In this paper, the authors consider a parametrized non-linear parabolic differential equation, which is motivated by lithium-ion battery models. A standard finite volume discretization leads to a high-dimensional discrete non-linear problem so that simulation of the parametrized problem for various different parameters is very costly. Therefore, the reduced-basis method is applied, so that the number of degrees of freedom is reduced significantly and a fast numerical simulation of the model is possible. To control the error, an a-posteriori error estimator is derived. Numerical experiments show the efficiency of the approach.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 362-379
Issue: 4
Volume: 22
Year: 2016
Month: 7
X-DOI: 10.1080/13873954.2016.1198387
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1198387
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:4:p:362-379
Template-Type: ReDIF-Article 1.0
Author-Name: E. Bader
Author-X-Name-First: E.
Author-X-Name-Last: Bader
Author-Name: Z. Zhang
Author-X-Name-First: Z.
Author-X-Name-Last: Zhang
Author-Name: K. Veroy
Author-X-Name-First: K.
Author-X-Name-Last: Veroy
Title: An empirical interpolation approach to reduced basis approximations for variational inequalities
Abstract:
Variational inequalities (VIs) are pervasive in mathematical modelling of equilibrium and optimization problems in engineering and science. Examples of applications include traffic network equilibrium problems, financial equilibrium, obstacle problems, lubrication phenomena and many others. Since these problems are computationally expensive to solve, we focus here on the development of model order reduction techniques, in particular the reduced basis technique. Reduced basis techniques for the approximation of solutions to elliptic VIs have been developed in the last few years. These methods apply to VIs of the so-called first kind, i.e. problems that can be equivalently described by a minimization of a functional over a convex set. However, these recent approaches are inapplicable to VIs of the so-called second kind, i.e. problems that involve minimization of a functional containing non-differentiable terms. In this article, we evaluate the feasibility of using the reduced basis method (RBM) combined with the empirical interpolation method (EIM) to treat VIs. In the proposed approach, the problem is approximated using a penalty or barrier method, and EIM is then applied to the penalty or barrier term. Numerical examples are presented to assess the performance of the proposed method, in particular the accuracy and computational efficiency of the approximation. Although the numerical examples involve only VIs of the first kind, we also evaluate the feasibility of using the RBM combined with the EIM to treat VIs of the second kind.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 345-361
Issue: 4
Volume: 22
Year: 2016
Month: 7
X-DOI: 10.1080/13873954.2016.1198388
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1198388
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:4:p:345-361
Template-Type: ReDIF-Article 1.0
Author-Name: B. Kramer
Author-X-Name-First: B.
Author-X-Name-Last: Kramer
Author-Name: S. Gugercin
Author-X-Name-First: S.
Author-X-Name-Last: Gugercin
Title: Tangential interpolation-based eigensystem realization algorithm for MIMO systems
Abstract:
The eigensystem realization algorithm (ERA) is a commonly used data-driven method for system identification and reduced-order modelling of dynamical systems. The main computational difficulty in ERA arises when the system under consideration has a large number of inputs and outputs, requiring to compute a singular value decomposition (SVD) of a large-scale dense Hankel matrix. In this work, we present an algorithm that aims to resolve this computational bottleneck via tangential interpolation. This involves projecting the original impulse response sequence onto suitably chosen directions. The resulting data-driven reduced model preserves stability and is endowed with an a priori error bound. Numerical examples demonstrate that the modified ERA algorithm with tangentially interpolated data produces accurate reduced models while, at the same time, reducing the computational cost and memory requirements significantly compared to the standard ERA. We also give an example to demonstrate the limitations of the proposed method.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 282-306
Issue: 4
Volume: 22
Year: 2016
Month: 7
X-DOI: 10.1080/13873954.2016.1198389
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1198389
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:4:p:282-306
Template-Type: ReDIF-Article 1.0
Author-Name: Martin Grepl
Author-X-Name-First: Martin
Author-X-Name-Last: Grepl
Author-Name: Boris Lohmann
Author-X-Name-First: Boris
Author-X-Name-Last: Lohmann
Author-Name: Jens Saak
Author-X-Name-First: Jens
Author-X-Name-Last: Saak
Title: Introduction
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 265-266
Issue: 4
Volume: 22
Year: 2016
Month: 7
X-DOI: 10.1080/13873954.2016.1198390
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1198390
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:4:p:265-266
Template-Type: ReDIF-Article 1.0
Author-Name: Alexander Pollok
Author-X-Name-First: Alexander
Author-X-Name-Last: Pollok
Author-Name: Andreas Klöckner
Author-X-Name-First: Andreas
Author-X-Name-Last: Klöckner
Author-Name: Dirk Zimmer
Author-X-Name-First: Dirk
Author-X-Name-Last: Zimmer
Title: Psychological aspects of equation-based modelling
Abstract:
Psychological aspects of equation-based modelling languages like Modelica are under-represented in literature. This does not reflect the growth of the corresponding userbase. In this paper we try to close this gap by tackling the problem from three sides: we conduct expert interviews, we conduct an experiment based on self-reported timings to analyse the effects of inheritance on understandability, and we conduct an online experiment to analyse the effects of model representations on the performance at modelling tasks. The expert interviews suggest that experienced modelling experts tend to develop their models from the top-down, while novices do the opposite. Results from the second experiment indicate that the effect of inheritance on the time to understand a model is both significant and large. The results of the last experiment imply that graphical representations outperform block-diagrams for several metrics. These results open a broad research field on the theory of good modelling practice.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 115-138
Issue: 2
Volume: 25
Year: 2019
Month: 3
X-DOI: 10.1080/13873954.2019.1594310
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1594310
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:2:p:115-138
Template-Type: ReDIF-Article 1.0
Author-Name: Thilo Moshagen
Author-X-Name-First: Thilo
Author-X-Name-Last: Moshagen
Title: On Meeting Energy Balance Errors in Co-Simulations
Abstract:
The term co-simulation denotes the coupling of some simulation tools for dynamical systems into one big system by having them exchange data at points of a fixed time grid and extrapolating the received data into the interval, while none of the steps is repeated for iteration. From the global perspective, the simulation thus has a strong explicit component. Frequently, among the data passed across subsystem boundaries there are flows of conserved quantities, and as there is no iteration of steps, system-wide balances may not be fulfilled: the system is not solved as one monolithic equation system. If these balance errors accumulate, simulation results become inaccurate. Balance correction methods which compensate these errors by adding corrections for the balances to the signal in the next coupling time step have been considered in past research. But establishing the balance of one quantity a posteriori due to the time delay in general cannot establish the balances of quantities that depend on the exchanged quantities, usually energy. In most applications from physics, the balance of energy is equivalent to stability. In this paper, a method is presented which allows users to choose the quantity that should be balanced to be that energy, and to accurately balance it. This establishes also numerical stability for many classes of stable problems.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 139-166
Issue: 2
Volume: 25
Year: 2019
Month: 3
X-DOI: 10.1080/13873954.2019.1595667
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1595667
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:2:p:139-166
Template-Type: ReDIF-Article 1.0
Author-Name: Elaheh Neshat
Author-X-Name-First: Elaheh
Author-X-Name-Last: Neshat
Author-Name: Rahim Khoshbakhti Saray
Author-X-Name-First: Rahim
Author-X-Name-Last: Khoshbakhti Saray
Title: Mathematical modeling and validation of mass transfer phenomenon in homogeneous charge compression ignition engines based on a thermodynamic multi zone model
Abstract:
The main purpose of the current study is mathematical modelling and validation of mass transfer phenomenon in homogeneous charge compression ignition engines. A validated multi-zone model coupled to a semi-detailed chemical kinetics is used to predict homogeneous charge compression ignition combustion and emissions. Heat and Mass transfer submodels are linked to the multi-zone model. Bulk flow and diffusion mass transfer between zones are considered. The results indicate that the diffusion mass transfer is negligible in homogeneous charge compression ignition engines. Bulk flow mass transfer plays a critical role in homogeneous charge compression ignition simulation and applying it in the multi-zone model leads to accurate prediction of the start of combustion, peak pressure and exhaust emissions. The results show that the maximum error changes from 90% to 5% in carbon monoxide prediction and from 98% to 14% in unburned hydrocarbons prediction, using the mass transfer submodel.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 167-194
Issue: 2
Volume: 25
Year: 2019
Month: 3
X-DOI: 10.1080/13873954.2019.1596957
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1596957
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:2:p:167-194
Template-Type: ReDIF-Article 1.0
Author-Name: Z. Nili Ahmadabadi
Author-X-Name-First: Z.
Author-X-Name-Last: Nili Ahmadabadi
Author-Name: Raynald Guilbault
Author-X-Name-First: Raynald
Author-X-Name-Last: Guilbault
Author-Name: Frédéric Laville
Author-X-Name-First: Frédéric
Author-X-Name-Last: Laville
Title: Nonlinear dynamic modeling of pneumatic nailing devices
Abstract:
This paper develops a mathematical modeling procedure for pneumatic nailing devices. The representation integrates all the operation phases composing the nailing process. The model accounts for the dynamics of the chamber pressures, the moving parts, the nonlinear interactions and impacts between the fixed and moving components, and includes the nail gun body and workpiece. All the system parameters integrated into the proposed model were established from experimental measurements. This model also integrates a nonlinear empirical formulation to predict the nail penetration resistance force. The final representation is validated through a comparison of the predicted piston motion and air pressures to experimental measurements made on a specific nail gun. The average of the percent error established at important time positions is lower than 7%.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 195-223
Issue: 2
Volume: 25
Year: 2019
Month: 3
X-DOI: 10.1080/13873954.2019.1601111
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1601111
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:2:p:195-223
Template-Type: ReDIF-Article 1.0
Author-Name: Christoph Hametner
Author-X-Name-First: Christoph
Author-X-Name-Last: Hametner
Author-Name: Christian H. Mayr
Author-X-Name-First: Christian H.
Author-X-Name-Last: Mayr
Author-Name: Martin Kozek
Author-X-Name-First: Martin
Author-X-Name-Last: Kozek
Author-Name: Stefan Jakubek
Author-X-Name-First: Stefan
Author-X-Name-Last: Jakubek
Title: Stability analysis of data-driven local model networks
Abstract:
This article discusses stability analysis of data-driven dynamic local model networks. In contrast to traditional fuzzy modelling, the structure and complexity of such model architectures is not unique when only observed input- and output data are available for their parametrization. The present article complements the well-known trade-off between accuracy and complexity by the notion of stability. For this purpose, existing Lyapunov stability criteria for local model networks are extended by a decay rate which represents a scalar and quantitative stability measure. It allows to compare models with different degrees of complexity also in view of their stability. For some of the commonly available Lyapunov stability criteria, the individual local model transitions are crucial. Therefore, in this article, an approach is introduced to determine the actually occurring model transitions by means of the identification data. The methods presented in the article are illustrated and discussed by means of a simulation example. It is shown how model complexity and the related approximation quality can have an adverse impact on the stability and how the outcome of different Lyapunov criteria is affected by the proper determination of local model transitions.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 224-247
Issue: 3
Volume: 20
Year: 2014
Month: 5
X-DOI: 10.1080/13873954.2013.821494
File-URL: http://hdl.handle.net/10.1080/13873954.2013.821494
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:3:p:224-247
Template-Type: ReDIF-Article 1.0
Author-Name: Diego Domínguez
Author-X-Name-First: Diego
Author-X-Name-Last: Domínguez
Author-Name: Jesús Gonzalo
Author-X-Name-First: Jesús
Author-X-Name-Last: Gonzalo
Author-Name: Deibi López
Author-X-Name-First: Deibi
Author-X-Name-Last: López
Title: Numerical modelling of a wind profiler system based on bubble tracking
Abstract:
Measuring atmospheric wind profiles is a difficult task which requires advanced, and normally expensive, technologies. The goal of this work is to provide the mathematical basis for a new and affordable system aiming at measuring local wind speed profiles by remotely tracking lighter-than-air bubbles. First of all, a detailed description of the system elements and the general configuration is included, followed by the mathematical tools involved in the measuring and filtering process. The capability of the proposed system to properly describe the horizontal wind in real time along the ascending path of the targets is modelled and verified with simulated scenarios. These simulations allowed to assess the accuracy and numerical stability of the measuring process as well as the relevance of different involved parameters. Results of simulated and field tests show the feasibility of the whole system and provide valuable data about optimal configuration. The success achieved in this preliminary work encourages us to move forward in the development of a prototype. It is expected that the operational version of the system could be a low-cost alternative to other wind profilers in certain conditions and applications, especially those related to air traffic management.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 209-223
Issue: 3
Volume: 20
Year: 2014
Month: 5
X-DOI: 10.1080/13873954.2013.823097
File-URL: http://hdl.handle.net/10.1080/13873954.2013.823097
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:3:p:209-223
Template-Type: ReDIF-Article 1.0
Author-Name: Zhiqin Qiao
Author-X-Name-First: Zhiqin
Author-X-Name-Last: Qiao
Author-Name: Xianyi Li
Author-X-Name-First: Xianyi
Author-X-Name-Last: Li
Title: Dynamical analysis and numerical simulation of a new Lorenz-type chaotic system
Abstract:
In this paper, a new 3D autonomous Lorenz-type chaotic system is modelled based on the condition that the system may generate chaos whereas it has only stable or non-hyperbolic equilibrium points. This system also includes some well-known Lorenz-like systems as its special cases, such as the diffusionless Lorenz system, the Burke-Shaw system and some other systems found. Although the new chaotic system is similar to other Lorenz-type systems in algebraic structure, they are topologically non-equivalent. This interesting fact motivates one to further investigate its dynamical behaviours, such as the number and the stability of equilibrium points, Hopf bifurcation and its direction, Poincaré maps, Lyapunov exponents and dissipativity, etc. Given numerical simulations not only verify the corresponding theoretically analytical results, but also demonstrate that this system possesses abundant and complex dynamical properties, which need further attention.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 264-283
Issue: 3
Volume: 20
Year: 2014
Month: 5
X-DOI: 10.1080/13873954.2013.824902
File-URL: http://hdl.handle.net/10.1080/13873954.2013.824902
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:3:p:264-283
Template-Type: ReDIF-Article 1.0
Author-Name: Xuefei Li
Author-X-Name-First: Xuefei
Author-X-Name-Last: Li
Author-Name: Guoqiang Wang
Author-X-Name-First: Guoqiang
Author-X-Name-Last: Wang
Author-Name: Zongwei Yao
Author-X-Name-First: Zongwei
Author-X-Name-Last: Yao
Author-Name: Yonghai Yang
Author-X-Name-First: Yonghai
Author-X-Name-Last: Yang
Title: Research on lateral stability and rollover mechanism of articulated wheel loader
Abstract:
A seven-degrees-of-freedom (DOF) dynamic model was established based on the Lagrange equation to analyse the lateral stability and instability mechanism of an articulated wheel loader. A scale wheel loader was designed and manufactured to validate the dynamic model in two conditions, namely turning on slopes and passing over obstacles. Experimental data and simulated data fitted well on the whole, so the developed dynamic model was proved to be useful and could serve as an important tool to analyse the stability of wheel loaders. At last, the lateral stability of one ZL50 wheel loader was analysed by using this dynamic model. The results showed that there is a phenomenon of sudden stability losing during the wheel loader cornering due to the relative rotation between the subframe and the rear axle. The subframe can enhance the stability when the wheel loader is passing over obstacles but reduces the stability when it is turning.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 248-263
Issue: 3
Volume: 20
Year: 2014
Month: 5
X-DOI: 10.1080/13873954.2013.825871
File-URL: http://hdl.handle.net/10.1080/13873954.2013.825871
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:3:p:248-263
Template-Type: ReDIF-Article 1.0
Author-Name: Wanyang Dai
Author-X-Name-First: Wanyang
Author-X-Name-Last: Dai
Title: Optimal control with monotonicity constraints for a parallel-server loss channel serving multi-class jobs
Abstract:
We study a parallel-server loss channel serving multi-class jobs, which appears in many real-world systems, e.g., cloud computing, multi-input multi-output (MIMO) orthogonal frequency division multiplexing (OFDM), and call centre. An $$\alpha $$α
-discounted optimal control with monotonicity constraints (OCMC) model over infinite time horizon is established by using the physical queueing model with linear revenue function. Existence of a solution to the OCMC model is proved, whose optimal value provides an upper bound of the corresponding values of the physical queueing model under Markovian decision rules. Algorithms with lower complexity in solving the OCMC model are proposed, which are further used to design an admission control policy for the loss channel. Furthermore, a simulation algorithm is proposed to implement the designed policy. Performance comparisons through numerical examples are conducted among our newly designed policy, the first-in first-out (FIFO) policy, an arbitrarily selected (AS) policy, and the Markov decision process (MDP) based threshold policy. Advantages and disadvantages of these policies are identified under different channel parameters and channel (e.g., Markovian and non-Markovian) conditions. Particularly, we find out that our designed policy outperforms the other three policies when the traffic intensity is relatively large, and the differences of the revenues per unit of time and the penalty costs among different classes of jobs are large.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 284-315
Issue: 3
Volume: 20
Year: 2014
Month: 5
X-DOI: 10.1080/13873954.2013.831359
File-URL: http://hdl.handle.net/10.1080/13873954.2013.831359
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:3:p:284-315
Template-Type: ReDIF-Article 1.0
Author-Name: Yan Kuang
Author-X-Name-First: Yan
Author-X-Name-Last: Kuang
Author-Name: David Ben-Arieh
Author-X-Name-First: David
Author-X-Name-Last: Ben-Arieh
Author-Name: Chih-Hang Wu
Author-X-Name-First: Chih-Hang
Author-X-Name-Last: Wu
Author-Name: Songnian Zhao
Author-X-Name-First: Songnian
Author-X-Name-Last: Zhao
Title: Using spatial games to model dynamic evolutionary systems
Abstract:
Modelling the dynamics of evolutionary competing species on a physical grid is a challenging modelling problem. This paper presents a novel modelling approach for synthesizing evolutionary dynamics of competing species using a spatial game perspective. This modelling approach describes the movement of players (‘species’ in our context) across a lattice. The model is based on a payoff function which controls the move likelihood and direction of the players (‘predators’ and ‘preys’). Using simulated results, the paper provides a comparison between the spatial game model and an existing predator-prey dynamic model. Finally, a case study is performed to illustrate the application of this formalism and validate the model.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 296-313
Issue: 3
Volume: 24
Year: 2018
Month: 5
X-DOI: 10.1080/13873954.2018.1437548
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1437548
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:3:p:296-313
Template-Type: ReDIF-Article 1.0
Author-Name: Noé Villa-Villaseñor
Author-X-Name-First: Noé
Author-X-Name-Last: Villa-Villaseñor
Author-Name: René Galindo-Orozco
Author-X-Name-First: René
Author-X-Name-Last: Galindo-Orozco
Title: Bond graph modelling of a 4-parameter photovoltaic array
Abstract:
A new model for simulating photovoltaic (PV) systems is presented. Bond Graph modelling is used as a basis technique. The proposed model allows prediction of generated energy under nonstandard conditions of temperature and irradiance. The proposed model is based on a 4-parameters model of the equivalent circuit of one diode. The proposed model has the property of being able to simulate the behaviour of a given PV module based only on information provided in the manufacturer datasheet. The proposed model also allows studying the effect of partial shading. As an advantage over other existing models of PV systems, the proposed model presents an extensive interconnection capacity. This feature allows simultaneous simulation with other subsystems to study the overall operation. For purposes of experimental validation of the proposed model, the construction of a $$V - I$$V−I
tracer based on MOSFET that acts as a variable load is performed. The hardware control and reading of the curves are made using a data acquisition board.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 275-295
Issue: 3
Volume: 24
Year: 2018
Month: 5
X-DOI: 10.1080/13873954.2018.1445649
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1445649
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:3:p:275-295
Template-Type: ReDIF-Article 1.0
Author-Name: Mian Jiang
Author-X-Name-First: Mian
Author-X-Name-Last: Jiang
Author-Name: Jigang Wu
Author-X-Name-First: Jigang
Author-X-Name-Last: Wu
Author-Name: Wenan Zhang
Author-X-Name-First: Wenan
Author-X-Name-Last: Zhang
Author-Name: Xuejun Li
Author-X-Name-First: Xuejun
Author-X-Name-Last: Li
Title: Empirical Gramian-based spatial basis functions for model reduction of nonlinear distributed parameter systems
Abstract:
Correct selection of spatial basis functions is crucial for model reduction for nonlinear distributed parameter systems in engineering applications. To construct appropriate reduced models, modelling accuracy and computational costs must be balanced. In this paper, empirical Gramian-based spatial basis functions were proposed for model reduction of nonlinear distributed parameter systems. Empirical Gramians can be computed by generalizing linear Gramians onto nonlinear systems, which results in calculations that only require standard matrix operations. Associated model reduction is described under the framework of Galerkin projection. In this study, two numerical examples were used to evaluate the efficacy of the proposed approach. Lower-order reduced models were achieved with the required modelling accuracy compared to linear Gramian-based combined spatial basis function- and spectral eigenfunction-based methods.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 258-274
Issue: 3
Volume: 24
Year: 2018
Month: 5
X-DOI: 10.1080/13873954.2018.1446448
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1446448
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:3:p:258-274
Template-Type: ReDIF-Article 1.0
Author-Name: Alessandro Castagnotto
Author-X-Name-First: Alessandro
Author-X-Name-Last: Castagnotto
Author-Name: Boris Lohmann
Author-X-Name-First: Boris
Author-X-Name-Last: Lohmann
Title: A new framework for $${\mathcal{H}}_2$$H2
-optimal model reduction
Abstract:
In this contribution, a new framework for $${{\mathcal H}_2}$$H2
-optimal reduction is presented, motivated by the local nature of both (tangential) interpolation and $${{\mathcal H}_2}$$H2
-optimal approximations. The main advantage is given by a decoupling of the cost of reduction from the cost of optimization, resulting in a significant speedup in $${{\mathcal H}_2}$$H2
-optimal reduction. In addition, a middle-sized surrogate model is produced at no additional cost and can be used e.g. for error estimation. Numerical examples illustrate the new framework, showing its effectiveness in producing $${{\mathcal H}_2}$$H2
-optimal reduced models at a far lower cost than conventional algorithms. Detailed discussions and optimality proofs are presented for applying this framework to the reduction of multiple-input, multiple-output linear dynamical systems. The paper ends with a brief discussion on how this framework could be extended to other system classes, thus indicating how this truly is a general framework for interpolatory $${{\mathcal H}_2}$$H2
reduction.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 236-257
Issue: 3
Volume: 24
Year: 2018
Month: 5
X-DOI: 10.1080/13873954.2018.1464030
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1464030
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:3:p:236-257
Template-Type: ReDIF-Article 1.0
Author-Name: The Editors
Title: Erratum
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: i-i
Issue: 3
Volume: 24
Year: 2018
Month: 5
X-DOI: 10.1080/13873954.2018.1475953
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1475953
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:3:p:i-i
Template-Type: ReDIF-Article 1.0
Author-Name: Valentín Valero
Author-X-Name-First: Valentín
Author-X-Name-Last: Valero
Author-Name: María-Emilia Cambronero
Author-X-Name-First: María-Emilia
Author-X-Name-Last: Cambronero
Title: Using unified modelling language to model the publish/subscribe paradigm in the context of timed Web services with distributed resources
Abstract:
In this paper, we present a unified modelling language (UML) framework to model timed Web services with distributed resources. We provide a graphical model of timed Web services that integrates the publish/subscribe paradigm in the context of distributed resources, with the goal that users have a formal framework to design this kind of systems. A formalization is then provided by using UML sequence diagrams with Combined Fragments (CFs) to represent the interactions between the roles involved and Web Services Resource Framework as a standard for the management of distributed resources. The formalization is based on a two-level process algebra. At the top level we have the CF description, and at the bottom the interactions inside them. An operational semantics is then defined for this model, and two case studies are presented to illustrate the applicability of this formalism.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 570-594
Issue: 6
Volume: 23
Year: 2017
Month: 11
X-DOI: 10.1080/13873954.2016.1277360
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1277360
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:6:p:570-594
Template-Type: ReDIF-Article 1.0
Author-Name: Ranran Liu
Author-X-Name-First: Ranran
Author-X-Name-Last: Liu
Author-Name: Tianhong Pan
Author-X-Name-First: Tianhong
Author-X-Name-Last: Pan
Author-Name: Shan Chen
Author-X-Name-First: Shan
Author-X-Name-Last: Chen
Author-Name: Zhengming Li
Author-X-Name-First: Zhengming
Author-X-Name-Last: Li
Title: Identification of non-uniformly sampled Wiener systems with dead-zone non-linearities
Abstract:
In multi-rate systems, identifying non-uniformly sampled data (NUSD) models is a challenge. This study proposes an iteratively recursive least-squares identification algorithm for non-uniformly sampled Wiener systems with dead-zone non-linearities. First, an extended information vector is designed, in which both unknown parameters and inner variables exist. Then, based on the auxiliary model and iterative method, an auxiliary model-based iteratively recursive least-squares algorithm is developed to estimate the system parameters directly. Furthermore, to improve the convergence rate and disturbance rejection, a new modified forgetting factor function is presented. Compared with no or fixed forgetting factor algorithms, the proposed algorithm has a higher convergence speed and is more robust to white noise with different variances. The numerical simulation shows the effectiveness of the proposed algorithm, and it can be extended to other NUSD non-linear systems.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 595-612
Issue: 6
Volume: 23
Year: 2017
Month: 11
X-DOI: 10.1080/13873954.2016.1278392
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1278392
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:6:p:595-612
Template-Type: ReDIF-Article 1.0
Author-Name: Mojahid Saeed Osman
Author-X-Name-First: Mojahid
Author-X-Name-Last: Saeed Osman
Author-Name: Bala Ram
Author-X-Name-First: Bala
Author-X-Name-Last: Ram
Title: Distributed scheduling approach for dynamic evacuation networks
Abstract:
The aim of this paper is to propose a novel distributed scheduling model for evacuation route scheduling from buildings and out of an affected area. The model is based on a hybrid approach that is spatio-temporal algorithm with optimization models as subproblems. The proposed distributed scheduling approach is an iterative process optimizing the one-step arrival of objects to each intermediate destination nodes at a time. To illustrate such an approach, we consider the problem of finding and scheduling evacuation paths from an urban building and out of a predetermined neighbourhood of the building on foot; the evacuation route involves pathways such as corridors, and stairs in buildings and road networks and sidewalks outside the building, there is a predefined set of exit points out of the target building and out of the road network serving the building. A well-known efficient heuristic algorithm is selected as a reference for comparative analysis and to illustrate the outperformance of the proposed approach in large-scale scenarios. The key results are the step-based optimal route schedules and the competitive evacuation time provided by the proposed distributed scheduling approach.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 554-569
Issue: 6
Volume: 23
Year: 2017
Month: 11
X-DOI: 10.1080/13873954.2017.1282879
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1282879
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:6:p:554-569
Template-Type: ReDIF-Article 1.0
Author-Name: A. Pfeffer
Author-X-Name-First: A.
Author-X-Name-Last: Pfeffer
Author-Name: T. Glück
Author-X-Name-First: T.
Author-X-Name-Last: Glück
Author-Name: W. Kemmetmüller
Author-X-Name-First: W.
Author-X-Name-Last: Kemmetmüller
Author-Name: A. Kugi
Author-X-Name-First: A.
Author-X-Name-Last: Kugi
Title: Mathematical modelling of a hydraulic accumulator for hydraulic hybrid drives
Abstract:
Hydraulic accumulators are used as energy storages in a wide area of applications. In particular, in automotive hybrid drive-trains, this type of energy storage is an interesting alternative to today’s common strategies like chemical batteries or flywheels. This article deals with the mathematical modelling of a hydraulic accumulator for passenger vehicles, which comprises a carbon fibre reinforced plastic (CFRP) body and aluminium piston. The thermodynamical behaviour of the oil and gas as well as the interaction with the CFRP body is investigated in detail. Starting from a complex model, two models of reduced complexity are derived. The validation of these models with measurement data from a test drive with a prototype series hydraulic hybrid drive-train proves their high accuracy.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 397-411
Issue: 5
Volume: 22
Year: 2016
Month: 9
X-DOI: 10.1080/13873954.2016.1174716
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1174716
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:5:p:397-411
Template-Type: ReDIF-Article 1.0
Author-Name: Gilberto Gonzalez
Author-X-Name-First: Gilberto
Author-X-Name-Last: Gonzalez
Author-Name: Aaron Padilla
Author-X-Name-First: Aaron
Author-X-Name-Last: Padilla
Title: Approximate bond graph models for linear singularly perturbed systems
Abstract:
A method for obtaining approximate bond graph models for linear time invariant (LTI) Multi-Input Multi-Output (MIMO) systems with singular perturbations is presented. The basic idea of using time-scale analysis in obtaining low-order models is to decouple the slow and fast models. This is achieved by using two-stage linear transformations. Hence, a procedure to construct decoupled bond graph models based on $$R$$R
-fields representing each dynamic of the singularly perturbed system is proposed.When the linear transformations are applied to the system with singular perturbations, non-linear and linear equations have to be solved for separating the subsystems. In many cases, the exact solutions of these equations are complicated, but approximate solutions can be determined and approximate models can be obtained.Thus, zeroth- and first-order solutions in a bond graph approach are proposed. The key to finding the approximate solutions is to obtain the relations of the original bond graph with a predefined integral causality of the system and another bond graph called the Singularly Perturbed Bond Graph whose storage elements of the fast dynamics have derivative causality and for the slow dynamics they maintain an integral causality assignment.Finally, the proposed method is applied to an illustrative example where the simulation results show the exact solutions and zeroth- and first-order approximations.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 412-443
Issue: 5
Volume: 22
Year: 2016
Month: 9
X-DOI: 10.1080/13873954.2016.1186100
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1186100
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:5:p:412-443
Template-Type: ReDIF-Article 1.0
Author-Name: Hongguang Li
Author-X-Name-First: Hongguang
Author-X-Name-Last: Li
Author-Name: Ming Li
Author-X-Name-First: Ming
Author-X-Name-Last: Li
Author-Name: Shengtong Zhou
Author-X-Name-First: Shengtong
Author-X-Name-Last: Zhou
Author-Name: Xiaohu Wang
Author-X-Name-First: Xiaohu
Author-X-Name-Last: Wang
Author-Name: Rui Zhu
Author-X-Name-First: Rui
Author-X-Name-Last: Zhu
Author-Name: Huiyu Bai
Author-X-Name-First: Huiyu
Author-X-Name-Last: Bai
Author-Name: Fucai Li
Author-X-Name-First: Fucai
Author-X-Name-Last: Li
Author-Name: Guang Meng
Author-X-Name-First: Guang
Author-X-Name-Last: Meng
Title: Rotor dynamics behavior of turbo-expander involving droplet impact
Abstract:
This paper dedicates on the rotor dynamics behaviour research on the turbo-expander rotor system involving droplet impact. A stochastic model based on Beta distribution and Bernoulli distribution of droplet generation is established and the formulations of droplet impact forces are deduced, which is applied on the rotor dynamics equations of the tilting pad bearing supported turbo-expander considering the temperature gradient for a further analysis. A time domain research is carried out and a conclusion that continuously droplet impact will perturb the steady vibration of the turbo-expander rotor system is obtained. Monte Carlo method is implemented for a statistics dynamics research and the results suggests that in the design of expander impellers, in order to decrease the uncertainty brought by droplet impact, the number of channels should be as few as possible, the droplet impact should be controlled to occur uniformly, and the collision, entrainment of the primary droplets and the stripping of the liquid film on the blade should be strictly restrained.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 444-462
Issue: 5
Volume: 22
Year: 2016
Month: 9
X-DOI: 10.1080/13873954.2016.1188830
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1188830
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:5:p:444-462
Template-Type: ReDIF-Article 1.0
Author-Name: M. Oumri
Author-X-Name-First: M.
Author-X-Name-Last: Oumri
Author-Name: A. Rachid
Author-X-Name-First: A.
Author-X-Name-Last: Rachid
Title: A mathematical model for pantograph-catenary interaction
Abstract:
Modelling the interaction between the pantograph and the catenary is an active field due to the development of high-speed trains. In this article, a 3D mathematical model based on finite element method is proposed to study the dynamic behaviour of the pantograph–catenary system. The equations of motion for a beam element have been discretized to obtain the weak form associated to each element of the catenary. The pantograph–catenary dynamic interaction model is implemented as a numerical simulation tool. The proposed model is compared to the performance of a commercial 3D simulator and it is faced to the requirements of the European Standard EN50318.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 463-474
Issue: 5
Volume: 22
Year: 2016
Month: 9
X-DOI: 10.1080/13873954.2016.1195412
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1195412
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:5:p:463-474
Template-Type: ReDIF-Article 1.0
Author-Name: Megha V. Trivedi
Author-X-Name-First: Megha V.
Author-X-Name-Last: Trivedi
Author-Name: Ravi N. Banavar
Author-X-Name-First: Ravi N.
Author-X-Name-Last: Banavar
Author-Name: Paul Kotyczka
Author-X-Name-First: Paul
Author-X-Name-Last: Kotyczka
Title: Hamiltonian modelling and buckling analysis of a nonlinear flexible beam with actuation at the bottom
Abstract:
The use of beams and similar structural elements is finding increasing application in many areas including micro and nanotechnology devices. For the purpose of buckling analysis and control, it is essential to account for nonlinear terms in the strains while modelling these flexible structures. Further, the Poisson’s effect can be accounted in modelling by the use of a two-dimensional stress–strain relationship. This paper studies the buckling effect for a slender, vertical beam (in the clamped-free configuration) with horizontal actuation at the fixed end and a tip-mass at the free end. Including also the inextensibility constraint of the beam, the equations of motion are derived. A preliminary modal analysis of the system has been carried out to describe candidate post-buckling configurations and study the stability properties of these equilibria. The vertical configuration of the beam under the action of gravity is without loss of generality, since the objective is to model a potential field that determines the equilibria. Neglecting the inextensibility constraint, the equations of motion are then casted in port-Hamiltonian form with appropriately defined flows and efforts as a basis for structure-preserving discretization and simulation. Finally, the finite-dimensional model is simulated to obtain the time response of the tip-mass for different loading conditions.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 475-492
Issue: 5
Volume: 22
Year: 2016
Month: 9
X-DOI: 10.1080/13873954.2016.1201517
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1201517
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:5:p:475-492
Template-Type: ReDIF-Article 1.0
Author-Name: O. Jellouli
Author-X-Name-First: O.
Author-X-Name-Last: Jellouli
Author-Name: A. Bernoussi
Author-X-Name-First: A.
Author-X-Name-Last: Bernoussi
Author-Name: M. Mâatouk
Author-X-Name-First: M.
Author-X-Name-Last: Mâatouk
Author-Name: M. Amharref
Author-X-Name-First: M.
Author-X-Name-Last: Amharref
Title: Forest fire modelling using cellular automata: application to the watershed Oued Laou (Morocco)
Abstract:
In this work, we consider the problem of modelling the phenomenon of forest fires using the cellular automata approach. The proposed model takes into account the main parameters that affect this phenomenon like nature and density of vegetation, humidity, wind, and altitude. We developed a decision-aided tool with JAVA which allows to analyse and format several hybrid collected data (satellite images, Digital Terrain Model) relatively to each studied area. The generated scenarios of forest fire spread in the study area will be considered as a guide for strategies in control and prevention of forest fires. As an application, we consider the watershed Oued Laou (Morocco).
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 493-507
Issue: 5
Volume: 22
Year: 2016
Month: 9
X-DOI: 10.1080/13873954.2016.1204321
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1204321
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:5:p:493-507
Template-Type: ReDIF-Article 1.0
Author-Name: Zhifu Chen
Author-X-Name-First: Zhifu
Author-X-Name-Last: Chen
Author-Name: Tianguang Chu
Author-X-Name-First: Tianguang
Author-X-Name-Last: Chu
Title: Multi-agent system model with mixed coupling topologies for pattern formation and formation splitting
Abstract:
In this article, a new type of multi-agent system model with mixed coupling topologies is proposed for realizing pattern formations with specific geometric shapes and formation splitting. The interactions among individual agents are assumed to be universally repulsive and selectively attractive. By designing the form of attractive coupling matrix, one can obtain a variety of formations with specific shapes in the system through self-assembly of agents. Both symmetric coupling case and asymmetric coupling case are considered. Analysis and simulation results show symmetric ones result in convergent dynamics to steady-state formations, whereas, for asymmetric case, the system exhibits complex dynamic behaviours, including collective rotation and chaotic motion. By breaking the graph defined by attractive couplings into disjoint subgraphs, one can make the formation of agents to split into small sizes. The results are relevant for the design of coordination and cooperative control for multi-agent systems.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 388-400
Issue: 4
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2012.750614
File-URL: http://hdl.handle.net/10.1080/13873954.2012.750614
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:4:p:388-400
Template-Type: ReDIF-Article 1.0
Author-Name: Ronald Thenius
Author-X-Name-First: Ronald
Author-X-Name-Last: Thenius
Author-Name: Michael Bodi
Author-X-Name-First: Michael
Author-X-Name-Last: Bodi
Author-Name: Thomas Schmickl
Author-X-Name-First: Thomas
Author-X-Name-Last: Schmickl
Author-Name: Karl Crailsheim
Author-X-Name-First: Karl
Author-X-Name-Last: Crailsheim
Title: Novel method of virtual embryogenesis for structuring Artificial Neural Network controllers
Abstract:
The organization of an Artificial Neural Network (ANN; e.g. the organization in layers, the number of cells per layer and the degree of connectivity between the cells) has a big influence on its abilities (e.g. learning ability). In this article, we present a novel method to organize the nodes and links of an ANN in a biologically motivated manner using virtual embryogenesis (VE). The VE mimics processes observable in biology, like interaction of cells via chemical substances or tissue differentiation. In our system, a virtual embryo consists of individual cells controlled by a genome. These cells can develop to nodes in the ANN during the embryogenetic process. The embryo is implemented as a spatially and temporally discrete multi-agent model. The cells in our model interact with each other via virtual physics and virtual chemistry. With the work at hand, we show that patterns developing in VE are comparable to patterns found during natural embryogenesis. We plan to combine VE with Evolutionary Algorithms to optimize the genome of the embryo. We expect the described model of VE (in combination with Evolutionary Algorithms) to lead to novel, evolutionary shaped net structures of ANNs.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 375-387
Issue: 4
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2012.756527
File-URL: http://hdl.handle.net/10.1080/13873954.2012.756527
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:4:p:375-387
Template-Type: ReDIF-Article 1.0
Author-Name: Murat Emre Kartal
Author-X-Name-First: Murat Emre
Author-X-Name-Last: Kartal
Author-Name: Alemdar Bayraktar
Author-X-Name-First: Alemdar
Author-X-Name-Last: Bayraktar
Title: Non-linear earthquake response of CFR DAM–reservoir–foundation systems
Abstract:
The aim of this article is to clearly show linear and non-linear earthquake behaviour of a concrete-faced rockfill (CFR) dam. For this purpose, a typical CFR dam model is considered with its reservoir water. Reservoir water is modelled by using fluid finite elements based on the Lagrangian approach. Free-field surface motions recorded during earthquakes are deconvolved to the base of the foundation from the soil layers for earthquake analysis. Geometrically and materially non-linear behaviours of the dam are considered in the finite element analysis. The Drucker–Prager model is used for concrete slab, and the multi-linear kinematic hardening model is used for rockfill and foundation rock in the materially non-linear analysis. Non-linear behaviour of the rockfill is obtained by the uniaxial stress–strain relation. Stress–strain curve of the rockfill is obtained using the shear modulus–shear strain relation produced for the gravels. Various joints in the CFR dam are modelled considering welded and friction contacts. In this study, one-dimensional surface-to-surface contact–target element pair based on the Coulomb's friction law provides friction. According to this study, maximum displacements appear when the friction is considered in the joints. In addition, hydrodynamic pressure increases the horizontal displacements of the dam. The horizontal displacements also increase by the effect of the non-linear behaviour of the rockfill and concrete slab.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 353-374
Issue: 4
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2012.759595
File-URL: http://hdl.handle.net/10.1080/13873954.2012.759595
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:4:p:353-374
Template-Type: ReDIF-Article 1.0
Author-Name: Gabriel Wurzer
Author-X-Name-First: Gabriel
Author-X-Name-Last: Wurzer
Title: In-process agent simulation for early stages of hospital planning
Abstract:
In the early stages of hospital planning, work processes are typically modelled in a static manner by using flow charts or business process modelling notation as means. Diagrams of this kind are easily simulated; however, employed process engines lack possibilities for dealing with dynamic aspects of the process which depend on the building layout (e.g. elevators, behaviour of automatic delivery carts). If one could give planners the opportunity to employ dynamic entities without having to change their usual workflow, one of the benefits would be that they are not being forced to resort to naive assumptions (e.g. 15 seconds per floor) that are still commonplace in today's planning practice. As another contribution, we show how agent-based simulation can be used as an analysis tool by using the state of the process simulation to generate arrivals.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 331-343
Issue: 4
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2012.761638
File-URL: http://hdl.handle.net/10.1080/13873954.2012.761638
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:4:p:331-343
Template-Type: ReDIF-Article 1.0
Author-Name: Singa Wang Chiu
Author-X-Name-First: Singa Wang
Author-X-Name-Last: Chiu
Author-Name: Chien-Hua Lee
Author-X-Name-First: Chien-Hua
Author-X-Name-Last: Lee
Author-Name: Feng-Tsung Cheng
Author-X-Name-First: Feng-Tsung
Author-X-Name-Last: Cheng
Author-Name: Chia-Kuan Ting
Author-X-Name-First: Chia-Kuan
Author-X-Name-Last: Ting
Title: Production–shipment policy for EPQ model with quality assurance and an improved delivery schedule
Abstract:
This article is concerned with determining the production–shipment policy for an economic production quantity model with quality assurance and an improved delivery schedule. We extend a recent work by Chiu et al. [Y.-S.P. Chiu, C.-A.K. Lin, H.-H. Chang, and V. Chiu, Mathematical modeling for determining economic batch size and optimal number of deliveries for EPQ model with quality assurance, Math. Comput. Model. Dyn. Sys. 16 (4) (2010), pp. 373–388] by incorporating an alternative delivery plan that aims at lowering the inventory holding cost for both supplier and buyer in such an integrated inventory system. Mathematical modelling along with Hessian matrix equations is used, and as a result the optimal production batch size and optimal number of deliveries are derived. A numerical example is provided to demonstrate the practical use of the results and the significant savings in stock holding costs for both vendor and buyer.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 344-352
Issue: 4
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2013.763282
File-URL: http://hdl.handle.net/10.1080/13873954.2013.763282
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:4:p:344-352
Template-Type: ReDIF-Article 1.0
Author-Name: B. Hametner
Author-X-Name-First: B.
Author-X-Name-Last: Hametner
Author-Name: T. Weber
Author-X-Name-First: T.
Author-X-Name-Last: Weber
Author-Name: C. Mayer
Author-X-Name-First: C.
Author-X-Name-Last: Mayer
Author-Name: J. Kropf
Author-X-Name-First: J.
Author-X-Name-Last: Kropf
Author-Name: S. Wassertheurer
Author-X-Name-First: S.
Author-X-Name-Last: Wassertheurer
Title: Calculation of arterial characteristic impedance: a comparison using different blood flow models
Abstract:
Within the concept of pulse wave analysis, arterial pressure and flow curves over a whole cardiac cycle are analysed. Characteristic impedance is obtained as ratio of pressure to flow when waves are not influenced by reflections. The aim of this work is to evaluate the effects of different blood flow models on the determination of the characteristic impedance compared to flow curves gained from ultrasound measurements. Beside a simple triangular and an averaged flow, a new blood flow model based on Windkessel theory is used. In a study population of 148 patients for the evaluation of the different models, the characteristic impedance is calculated in the frequency domain. The results indicate that the characteristic impedance strongly depends on the accuracy of the used flow model. While the averaged and the ARCSolver flow provide good estimates for impedance, the triangular flow curve seems to be too simplistic for getting accurate values.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 319-330
Issue: 4
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2013.763831
File-URL: http://hdl.handle.net/10.1080/13873954.2013.763831
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:4:p:319-330
Template-Type: ReDIF-Article 1.0
Author-Name: Johan Mailier
Author-X-Name-First: Johan
Author-X-Name-Last: Mailier
Author-Name: Andres Donoso-Bravo
Author-X-Name-First: Andres
Author-X-Name-Last: Donoso-Bravo
Author-Name: Alain Vande Wouwer
Author-X-Name-First: Alain Vande
Author-X-Name-Last: Wouwer
Title: On the derivation of simple dynamic models of anaerobic digestion using macroscopic bioreaction schemes
Abstract:
In this study, the problem of developing simple dynamic models of an anaerobic digestion process is tackled using an identification procedure which proceeds in several consecutive steps. Starting from sets of experimental data describing the time evolution of several key component concentrations, i.e. biomass(es), substrates and products, the minimal number of macroscopic bioreactions required to represent the data at hand, as well as the parameters of the associated stoichiometry matrix, are determined using maximum likelihood principal component analysis. Then, the structure of the kinetic laws, together with their parameters, are identified using likelihood ratio tests to navigate through the branches of decision trees made of various kinetic structures. The effectiveness of the modelling procedure is illustrated with a simulated example of anaerobic digestion. As usual sensors only provide aggregate measurements of the component concentration, a deeper investigation of practical identifiability is achieved in relation with the influence of measurement errors.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 301-318
Issue: 4
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2013.764535
File-URL: http://hdl.handle.net/10.1080/13873954.2013.764535
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:4:p:301-318
Template-Type: ReDIF-Article 1.0
Author-Name: S. Kartal
Author-X-Name-First: S.
Author-X-Name-Last: Kartal
Author-Name: M. Kar
Author-X-Name-First: M.
Author-X-Name-Last: Kar
Author-Name: N. Kartal
Author-X-Name-First: N.
Author-X-Name-Last: Kartal
Author-Name: F. Gurcan
Author-X-Name-First: F.
Author-X-Name-Last: Gurcan
Title: Modelling and analysis of a phytoplankton–zooplankton system with continuous and discrete time
Abstract:
In this study, a phytoplankton–zooplankton system has been modelled using a system of differential equations with piecewise constant arguments, which represents a new approach to modelling phytoplankton–zooplankton interaction. To analyse the dynamic behaviour of the model, we consider the solution of the system in a certain subinterval, which yields a system of difference equations. Some theoretical results on the boundedness character and local stability properties for the discrete dynamical system are obtained. In addition, we explain the biological dynamics of the bloom in the plankton model through Neimark–Sacker bifurcation and obtain the threshold values for different parameters that govern the periodic nature of the bloom. We conclude that, while other studies explained that the bloom depended on only one parameter, this study explains that the bloom depended on three different parameters, namely $$\theta $$θ
(rate of toxin production per phytoplankton), $$\beta $$β
(zooplankton growth efficiency) and $$K$$K
(environmental carrying capacity of phytoplankton).
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 539-554
Issue: 6
Volume: 22
Year: 2016
Month: 11
X-DOI: 10.1080/13873954.2016.1204323
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1204323
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:6:p:539-554
Template-Type: ReDIF-Article 1.0
Author-Name: K. K. Yum
Author-X-Name-First: K. K.
Author-X-Name-Last: Yum
Author-Name: E. Pedersen
Author-X-Name-First: E.
Author-X-Name-Last: Pedersen
Title: Architecture of model libraries for modelling turbocharged diesel engines
Abstract:
Turbocharged diesel engines are complex engineering systems, which have a wide range of applications. Numerical simulations of the engine system for its performance, fuel economy and emissions offer affordable possibilities to improve the engine system itself and, furthermore, to optimize a larger system, such as a power plant and a marine propulsion system. As the simulation models of the diesel engines are used in a wide range of contexts, a library-based modelling approach provides benefits of making a modelling process and maintenance of the existing models easier. The model library should not be just a catalogue of the models but has to provide a solid model structure on different levels of abstraction and, therefore, guide the modeller to make appropriate decisions in a step-by-step manner at each level. Such a model structure consists of a technical component level, a physical concept level and a mathematical level. In this paper, application of the model structure to build a library for modelling turbocharged diesel engines is presented. For each level, a general framework is explained with practical examples. Finally, a procedure for building an engine system simulation model is demonstrated using a specific diesel engine model.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 584-612
Issue: 6
Volume: 22
Year: 2016
Month: 11
X-DOI: 10.1080/13873954.2016.1204324
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1204324
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:6:p:584-612
Template-Type: ReDIF-Article 1.0
Author-Name: Lei Wen
Author-X-Name-First: Lei
Author-X-Name-Last: Wen
Author-Name: Lu Bai
Author-X-Name-First: Lu
Author-X-Name-Last: Bai
Author-Name: Ernv Zhang
Author-X-Name-First: Ernv
Author-X-Name-Last: Zhang
Author-Name: Jianfeng Weng
Author-X-Name-First: Jianfeng
Author-X-Name-Last: Weng
Title: A system dynamics model for industrial carbon emissions in Baoding
Abstract:
Baoding, as one of the first batch of low-carbon pilot cities and heavily industrial energy consumers, faces more responsibilities to adjust industrial structure and mitigate carbon emissions. The purpose of this study is aimed at predicting and comparing industrial carbon emissions of Baoding in 11 scenarios under different policy focus, and then providing emission-cutting recommendations. In view of various scenarios issues, system dynamics has been applied to predict and simulate. To begin with, the model has been established following the step of causal loop diagram and stock flow diagram. Moreover, before we employ the model to predict and simulate, historical test is adopted via the comparison of simulated data and historical data in 2005–2013. Besides, this paper decomposes scenarios factors into energy structure, high-energy-consumption enterprises and growth rate of industrial output. The simulation results show that the prospect of carbon-emission issues in Baoding is not cheerful. Hence, some recommendations about low-carbon mode in Baoding’s industrial carbon emissions have been proposed according to simulation results.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 555-568
Issue: 6
Volume: 22
Year: 2016
Month: 11
X-DOI: 10.1080/13873954.2016.1206025
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1206025
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:6:p:555-568
Template-Type: ReDIF-Article 1.0
Author-Name: A. Ostermann
Author-X-Name-First: A.
Author-X-Name-Last: Ostermann
Author-Name: G. Spielberger
Author-X-Name-First: G.
Author-X-Name-Last: Spielberger
Author-Name: A. Tributsch
Author-X-Name-First: A.
Author-X-Name-Last: Tributsch
Title: Detecting structural changes with ARMA processes
Abstract:
In this paper, we discuss the application of autoregressive moving average (ARMA) processes in structural health monitoring. For this aim, we consider a linear system of differential equations driven by white noise, which could be seen as a continuous time model of an engineering structure under ambient excitation. A single component of the solution of such a system reflects the position or velocity of a fixed point of the observed structure. We first show that every such component behaves like an ARMA process. These considerations are illustrated by an example, where we show how the natural frequencies can be calculated from the process coefficients. However, the main focus of the paper lies in the detection of structural changes with ARMA processes. For this purpose, we propose a new distance measure that relies on the one-step prediction errors and some sampling strategies. Two case studies are included, which serve to demonstrate the performance of the proposed method. The first one is an off-duty steel truss railway bridge, followed by an in-depth study of an aluminium shear frame construction. In the latter case scenario, we show that the distance measure increases with increasing damage extent.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 524-538
Issue: 6
Volume: 22
Year: 2016
Month: 11
X-DOI: 10.1080/13873954.2016.1213752
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1213752
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:6:p:524-538
Template-Type: ReDIF-Article 1.0
Author-Name: Peter Benner
Author-X-Name-First: Peter
Author-X-Name-Last: Benner
Author-Name: Jens Saak
Author-X-Name-First: Jens
Author-X-Name-Last: Saak
Author-Name: M. Monir Uddin
Author-X-Name-First: M. Monir
Author-X-Name-Last: Uddin
Title: Structure preserving model order reduction of large sparse second-order index-1 systems and application to a mechatronics model
Abstract:
Nowadays, mechanical engineers heavily depend on mathematical models for simulation, optimization and controller design. In either of these tasks, reduced dimensional formulations are obligatory in order to achieve fast and accurate results. Usually, the structural mechanical systems of machine tools are described by systems of second-order differential equations. However, they become descriptor systems when extra constraints are imposed on the systems. This article discusses efficient techniques of Gramian-based model-order reduction for second-order index-1 descriptor systems. Unlike, our previous work, here we mainly focus on a second-order to second-order reduction technique for such systems, where the stability of the system is guaranteed to be preserved in contrast to the previous approaches. We show that a special choice of the first-order reformulation of the system allows us to solve only one Lyapuov equation instead of two. We also discuss improvements of the technique to solve the Lyapunov equation using low-rank alternating direction implicit methods, which further reduces the computational cost as well as memory requirement. The proposed technique is applied to a structural finite element method model of a micro-mechanical piezo-actuators-based adaptive spindle support. Numerical results illustrate the increased efficiency of the adapted method.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 509-523
Issue: 6
Volume: 22
Year: 2016
Month: 11
X-DOI: 10.1080/13873954.2016.1218347
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1218347
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:6:p:509-523
Template-Type: ReDIF-Article 1.0
Author-Name: Olusegun J. Ilegbusi
Author-X-Name-First: Olusegun J.
Author-X-Name-Last: Ilegbusi
Author-Name: Nadun Kuruppumullage
Author-X-Name-First: Nadun
Author-X-Name-Last: Kuruppumullage
Author-Name: Erin Silverman
Author-X-Name-First: Erin
Author-X-Name-Last: Silverman
Author-Name: Vicki Lewis
Author-X-Name-First: Vicki
Author-X-Name-Last: Lewis
Author-Name: Jeffrey Lehman
Author-X-Name-First: Jeffrey
Author-X-Name-Last: Lehman
Author-Name: Bari Hoffman Ruddy
Author-X-Name-First: Bari Hoffman
Author-X-Name-Last: Ruddy
Title: Mathematical modelling of tongue deformation during swallow in patients with head and neck cancer
Abstract:
Cancer localized to the tongue is often characterized by increased stiffness in the affected region. This stiffness affects swallow in a manner that is difficult to quantify in patients. A biomechanical model was developed to simulate the spatio-temporal deformation of the tongue during the pharyngeal phase of swallow in patients with cancer of the tongue base. The model involves finite element analysis (FEA) of a three-dimensional (3D) model of the tongue reconstructed from magnetic resonance images (MRI). The tongue tissue is assumed to be hyper-elastic. In order to examine the effects of tissue change (increased stiffness) due to the presence of cancer localized to the tongue base, various sections of the 3D geometry are modified to exhibit different elastic properties. Three cases are considered, representing the normal tongue, a tongue with early-stage cancer, and tongue with late-stage cancer. Early- and late-stage cancers are differentiated by the degree of stiffness within the base of tongue tissue. Analysis of the model suggests that healthy tongue has a maximum deformation of 9.38 mm, whereas tongues having mild cancer and severe cancer have a maximum deformation of 8.65 and 6.17 mm, respectively. Biomechanical modelling is a useful tool to explain and estimate swallowing abnormalities associated with tongue cancer and post-treatment characteristics.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 569-583
Issue: 6
Volume: 22
Year: 2016
Month: 11
X-DOI: 10.1080/13873954.2016.1220015
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1220015
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Handle: RePEc:taf:nmcmxx:v:22:y:2016:i:6:p:569-583
Template-Type: ReDIF-Article 1.0
Author-Name: Chinh Ngo
Author-X-Name-First: Chinh
Author-X-Name-Last: Ngo
Author-Name: Jeehyun Jung
Author-X-Name-First: Jeehyun
Author-X-Name-Last: Jung
Author-Name: Chuong Nguyen
Author-X-Name-First: Chuong
Author-X-Name-Last: Nguyen
Author-Name: Jongwon Seok
Author-X-Name-First: Jongwon
Author-X-Name-Last: Seok
Title: An accurate regenerative chatter model in the ball-end milling process that considers high feed rate and shallow axial immersion conditions
Abstract:
This paper proposes an accurate model of a ball-end milling process that considers high feed rate and shallow axial immersion conditions with multiple varying time delays (VTDs) to determine the stability of the system. The criteria that the time delay must satisfy are derived. The effect of the feed motion on the entry and exit cutting angles is discussed herein for the first time to the authors’ knowledge in the ball-end milling process. The system dynamics are described by a set of delay differential equations (DDEs) with periodic coefficients and multiple VTDs. In this paper, an improved semi-discretization method (ISDM) is also proposed to determine the stability of the VTD system, which greatly extends the computational efficiency. Then, a discrete dynamical map is deduced to establish the state transition matrix over one time period to predict the stability via the Floquet theory. The improvement of the proposed ISDM is validated by comparing the results with those in other studies.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 453-475
Issue: 5
Volume: 23
Year: 2017
Month: 9
X-DOI: 10.1080/13873954.2016.1258423
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1258423
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:5:p:453-475
Template-Type: ReDIF-Article 1.0
Author-Name: M. Kebdani
Author-X-Name-First: M.
Author-X-Name-Last: Kebdani
Author-Name: G. Dauphin-Tanguy
Author-X-Name-First: G.
Author-X-Name-Last: Dauphin-Tanguy
Author-Name: A. Dazin
Author-X-Name-First: A.
Author-X-Name-Last: Dazin
Author-Name: R. Albach
Author-X-Name-First: R.
Author-X-Name-Last: Albach
Author-Name: P. Dupont
Author-X-Name-First: P.
Author-X-Name-Last: Dupont
Title: Two-phase reservoir: development of a transient thermo-hydraulic model based on bond graph approach with experimental validation
Abstract:
The main purpose of the project FUI THERMOFLUID is to study the feasibility of a new electronic cooling system embedded on flying objects (missile, satellite, and airplane). The technology chosen consists of a pumped two-phase flow cooling loop (PTPFL). It is an innovative technology with a transport capacity of the thermal power up to 10 MW.m, exceeding in this way the performance of all other technologies. A PTPFL is a cooling loop based on the exploitation of the latent heat properties of the fluid trapped inside the loop, and moved by a pump. The components constituting a PTPFL are: a two-phase reservoir (TP-R), a mini-channels evaporator, a brazed plate condenser, a pump, and pipes. The global research work is devoted to propose a dynamic model and experimental validation of the PTPFL. The present article is exclusively dedicated to the TP-R. Indeed, this element plays a key role in the functioning of PTPFL. Historically, the TP-R did not equip the first cooling loop. However, due to its advantages, its introduction was essential. The developed dynamic model will be used in another work to predict the thermal hydraulic efficiency of the PTPFL from its mechanical and fluidic parameters, to conduct the study of transitional regimes and instability problems, and provides an original tool dedicated to design the TP-R in function of the thermal power levels to be evacuated and the selected refrigerant. The bond graph methodology is adopted for modelling works because of its energetic approach and multi-physics character of the studied system. The new model proposed in this article has many originalities: First, it is based on bond graph approach. Nowadays, the open literature shows that no bond graph model has been developed for such thermo-fluid system. Second, the dynamic model of TP-R pays great attention to phenomena that have never been taken into account in works cited in the present article, such as evaporation and condensation. Third, different conducto-convective heat exchanges are modelled without any experimental recalibration of the thermal exchange coefficients, unlike models proposed in the literature. In fact, all coefficients are systematically calculated using adequate correlations.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 476-503
Issue: 5
Volume: 23
Year: 2017
Month: 9
X-DOI: 10.1080/13873954.2016.1259635
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1259635
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:5:p:476-503
Template-Type: ReDIF-Article 1.0
Author-Name: Raphael N. Hofstädter
Author-X-Name-First: Raphael N.
Author-X-Name-Last: Hofstädter
Author-Name: Thomas Zero
Author-X-Name-First: Thomas
Author-X-Name-Last: Zero
Author-Name: Christian Dullinger
Author-X-Name-First: Christian
Author-X-Name-Last: Dullinger
Author-Name: Gregor Richter
Author-X-Name-First: Gregor
Author-X-Name-Last: Richter
Author-Name: Martin Kozek
Author-X-Name-First: Martin
Author-X-Name-Last: Kozek
Title: Heat capacity and heat transfer coefficient estimation for a dynamic thermal model of rail vehicles
Abstract:
This paper provides a method for estimating the parameters of a dynamic thermal rail vehicle model and reference values of these parameters. A linear dynamic discrete time system is used to model the thermal behaviour of the vehicle relevant for thermal comfort and air conditioning. The heat capacities and the heat transfer coefficients are stated for various vehicle classes. While dynamic thermal models are state of the art in buildings, cars and rail vehicles, no reference values can be found for these parameters. This paper shows how to estimate the heat capacity and the heat transfer coefficient from measured data for a given thermal model structure. Two different measurement data sources are used: special experiments and existing measurements. While specially designed experiments are only possible for new measurements, it is shown that satisfying results can be obtained with existing measurements. Measurement data from 13 vehicles are used to provide reference values for all passenger vehicles classes: tram, metro, regional and main-line. If all assumptions are satisfied, simulation results of the indoor air temperature agree well with measurements. Reference values for parameters of a dynamic thermal model are the basis for a wide application of such models in the rail vehicle industry.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 439-452
Issue: 5
Volume: 23
Year: 2017
Month: 9
X-DOI: 10.1080/13873954.2016.1263670
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1263670
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:5:p:439-452
Template-Type: ReDIF-Article 1.0
Author-Name: F. Lotero
Author-X-Name-First: F.
Author-X-Name-Last: Lotero
Author-Name: F. Couenne
Author-X-Name-First: F.
Author-X-Name-Last: Couenne
Author-Name: B. Maschke
Author-X-Name-First: B.
Author-X-Name-Last: Maschke
Author-Name: D. Sbarbaro
Author-X-Name-First: D.
Author-X-Name-Last: Sbarbaro
Title: Distributed parameter bi-zone model with moving interface of an extrusion process and experimental validation
Abstract:
In this work, a distributed parameter bi-zone dynamic model with moving interface of an extrusion process is presented. In this case, a variable viscosity is assumed along the extruder. A finite volume method is proposed for discretizing the dynamic model. The steady-state values of the variables were calculated by using an efficient optimization algorithm. Experimental tests performed with an industrial type twin screw extruder are compared against simulations for the case of variable screw speed and constant feed rate. The comparison shows good qualitative agreement between experimental and simulation results. This model can be used to design observers for estimating non-measurable variables as well as advanced control strategies.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 504-522
Issue: 5
Volume: 23
Year: 2017
Month: 9
X-DOI: 10.1080/13873954.2016.1278393
File-URL: http://hdl.handle.net/10.1080/13873954.2016.1278393
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:5:p:504-522
Template-Type: ReDIF-Article 1.0
Author-Name: Zbigniew Kamiński
Author-X-Name-First: Zbigniew
Author-X-Name-Last: Kamiński
Title: A simplified lumped parameter model for pneumatic tubes
Abstract:
Tubes are commonly used in pneumatic systems for transferring energy and control signals. Using the control volume method, a mathematical tube model has been developed, which takes into account the effect of resistance, capacitance and inertance on the dynamic properties of control and supply circuits of pneumatic systems. The adequacy of the computer model developed in Matlab/Simulink was verified by comparing the results of simulation studies with the results of experimental tests of airflow through tubes of varying diameter and length. The advantage of the computer model is the capability to model pneumatic systems under varying conditions of heat exchange with the environment by changing the coefficient of the polytropic process coefficient.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 523-535
Issue: 5
Volume: 23
Year: 2017
Month: 9
X-DOI: 10.1080/13873954.2017.1280512
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1280512
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:5:p:523-535
Template-Type: ReDIF-Article 1.0
Author-Name: Richard Kern
Author-X-Name-First: Richard
Author-X-Name-Last: Kern
Title: Physical modelling of a long pneumatic transmission line: models of successively decreasing complexity and their experimental validation
Abstract:
There exist a significant number of models, which describe the dynamics of pneumatic transmission lines. The models are based on different assumptions and, thereby, vary in the physical phenomena they incorporate. These assumptions made are not always stated clearly and the models are rarely validated with measurement data. The aim of this article is to present multiple distributed parameter models that, starting from a physical system description, successively decrease in complexity and finally result in a rather simple system representation. Data, both from simulation studies as well as from a pneumatic test bench, serve as a quantitative validation of these assumptions. Based on a detailed discussion of the different models, this article aims at facilitating the choice of an appropriate model for a given task where the effect of long pneumatic transmission lines cannot be neglected and a trade-off between accuracy and complexity is required.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 536-553
Issue: 5
Volume: 23
Year: 2017
Month: 9
X-DOI: 10.1080/13873954.2017.1282880
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1282880
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:5:p:536-553
Template-Type: ReDIF-Article 1.0
Author-Name: M. Gokhan Habiboglu
Author-X-Name-First: M. Gokhan
Author-X-Name-Last: Habiboglu
Author-Name: Yagmur Denizhan
Author-X-Name-First: Yagmur
Author-X-Name-Last: Denizhan
Title: Development of a macro-scale model from a meso-scale model for cell culture population dynamics
Abstract:
In this paper, we present a novel macro-scale analytical model that allows the prediction of how the population size will change in a cell culture starting from an arbitrary initial value. General biological knowledge and some empirical observations are used to design an agent-based discrete-time model at the meso-scale, which then serves as a simulation environment and provides the necessary insights for the development of the continuous-time, differential equation-based, compact macro-scale model. This model can be parameter-tuned and employed for predicting how the population size changes. The paper gives a procedure for the estimation of parameter values of the macro-scale model via some simple tests to be conducted on the cell culture at hand. The performance of the macro-scale model is validated via simulation results that show how well the macro-scale model captures the population dynamics as obtained from the meso-scale model, while the biological plausibility of the meso-scale model is taken for granted.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 228-250
Issue: 3
Volume: 21
Year: 2015
Month: 5
X-DOI: 10.1080/13873954.2014.929151
File-URL: http://hdl.handle.net/10.1080/13873954.2014.929151
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:3:p:228-250
Template-Type: ReDIF-Article 1.0
Author-Name: Michael Baumgart
Author-X-Name-First: Michael
Author-X-Name-Last: Baumgart
Author-Name: Andreas Steinboeck
Author-X-Name-First: Andreas
Author-X-Name-Last: Steinboeck
Author-Name: Thomas Kiefer
Author-X-Name-First: Thomas
Author-X-Name-Last: Kiefer
Author-Name: Andreas Kugi
Author-X-Name-First: Andreas
Author-X-Name-Last: Kugi
Title: Modelling and experimental validation of the deflection of a leveller for hot heavy plates
Abstract:
In order to successfully automate levelling processes, in particular for heavy plates, the deflection of the leveller has to be compensated based on a deflection model. In this work, a detailed mathematical deflection model of a hot leveller with bending mechanism and its experimental validation are presented. The roll intermesh profiles are calculated based on the deflection of the work rolls that are elastically supported by support rolls, frames, posts and adjustment screws. The deflection model is suited to compensate the effect of deflection on the roll intermesh and the plate flatness as well as to assess the loads of critical parts, for example the support rolls. A new experimental design to measure the deflection of a leveller is presented and successfully applied for model validation. The work roll deflection is measured directly by means of displacement sensors that are inserted in cut-outs of test plates. These test plates are modelled as linear elastic stripes. For normal load levels, the relative accuracy (repeatability) of the roll intermesh prediction of the model is better than 0.08 mm.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 202-227
Issue: 3
Volume: 21
Year: 2015
Month: 5
X-DOI: 10.1080/13873954.2014.941881
File-URL: http://hdl.handle.net/10.1080/13873954.2014.941881
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:3:p:202-227
Template-Type: ReDIF-Article 1.0
Author-Name: Alessandro Vittorio Papadopoulos
Author-X-Name-First: Alessandro Vittorio
Author-X-Name-Last: Papadopoulos
Author-Name: Martina Maggio
Author-X-Name-First: Martina
Author-X-Name-Last: Maggio
Author-Name: Federico Terraneo
Author-X-Name-First: Federico
Author-X-Name-Last: Terraneo
Author-Name: Alberto Leva
Author-X-Name-First: Alberto
Author-X-Name-Last: Leva
Title: A dynamic modelling framework for control-based computing system design
Abstract:
This manuscript proposes a novel viewpoint on computing systems’ modelling. The classical approach is to consider fully functional systems and model them, aiming at closing some external loops to optimize their behaviour. On the contrary, we only model strictly physical phenomena, and realize the rest of the system as a set of controllers. Such an approach permits rigorous assessment of the obtained behaviour in mathematical terms, which is hardly possible with the heuristic design techniques, that were mainly adopted to date. The proposed approach is shown at work with three relevant case studies, so that a significant generality can be inferred from it.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 251-271
Issue: 3
Volume: 21
Year: 2015
Month: 5
X-DOI: 10.1080/13873954.2014.942785
File-URL: http://hdl.handle.net/10.1080/13873954.2014.942785
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:3:p:251-271
Template-Type: ReDIF-Article 1.0
Author-Name: R. González
Author-X-Name-First: R.
Author-X-Name-Last: González
Author-Name: J.I. Giribet
Author-X-Name-First: J.I.
Author-X-Name-Last: Giribet
Author-Name: H.D. Patiño
Author-X-Name-First: H.D.
Author-X-Name-Last: Patiño
Title: An approach to benchmarking of loosely coupled low-cost navigation systems
Abstract:
New solutions to the navigation problem related to low-cost integrated navigation systems (INS) are often published. Since these new solutions are generally compared with ad hoc mathematical models that are not fully exposed, one cannot be sure of the relative improvements. In this work, complete mathematical model for a low-cost INS is suggested to be used as a benchmarking. As far as the authors’ knowledge, a benchmarking for low-cost INS has not been previously reported. Shown INS comprises a strapdown inertial navigation system, loosely coupled to a GPS receiver. The INS mathematical model is based upon classical navigation equations and classical sensor models, both from recognized authors. The algorithm that details the INS operation is also presented. The benchmarking is provided as an open-source toolbox for MATLAB. Additionally, this work can be taken as a starting point for new practitioners in the INS field. To validate the INS mathematical model, real-world data sets from three different Micro Electro-Mechanical Systems (MEMS) inertial measurement units (IMU) and a GPS receiver are processed. It is observed that obtained RMS errors from the three INS are coherent with the quality of corresponding MEMS IMU. This confirms that the proposed benchmarking is a suitable tool to evaluate objectively new solutions to low-cost INS.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 272-287
Issue: 3
Volume: 21
Year: 2015
Month: 5
X-DOI: 10.1080/13873954.2014.952642
File-URL: http://hdl.handle.net/10.1080/13873954.2014.952642
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:3:p:272-287
Template-Type: ReDIF-Article 1.0
Author-Name: B.P. Minaker
Author-X-Name-First: B.P.
Author-X-Name-Last: Minaker
Title: The tangent stiffness matrix in rigid multibody vehicle dynamics
Abstract:
In the development of the equations of motion of a rigid multibody system, particularly vehicles, it is quite common to linearize the equations after they are derived, or even to ignore the non-linear terms from the outset. When doing so, the tangent stiffness matrix, i.e., the stiffness term that results from preload of the system rather than physical flexibility, is often ignored. The motion analysis of preloaded mechanical systems, e.g., the ride quality analysis of vehicle suspensions, may be significantly altered by this omission. Explicit expressions for the tangent stiffness matrix for a few of the common constraint types, including the revolute joint and the rolling wheel, are derived in this article. These expressions are coded into software and included in an open-source linear equation of motion generator for rigid multibody systems. A sample automotive suspension system is analysed, comparing the results with and without the tangent stiffness matrix effects; additionally, a benchmark solution is developed using a commercial multibody dynamics code. The results provide confirmation of the significance of the tangent stiffness effect on motion analysis and correlate well with non-linear transient solutions.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 288-310
Issue: 3
Volume: 21
Year: 2015
Month: 5
X-DOI: 10.1080/13873954.2014.953549
File-URL: http://hdl.handle.net/10.1080/13873954.2014.953549
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:3:p:288-310
Template-Type: ReDIF-Article 1.0
Author-Name: Gilberto Gonzalez Avalos
Author-X-Name-First: Gilberto
Author-X-Name-Last: Gonzalez Avalos
Author-Name: Noe Barrera Gallegos
Author-X-Name-First: Noe
Author-X-Name-Last: Barrera Gallegos
Title: Quasi-steady state model determination for systems with singular perturbations modelled by bond graphs
Abstract:
A bond graph model for a singularly perturbed system is presented. This system is characterized by fast and slow dynamics. In addition, the bond graph can have storage elements with derivative and integral causality assignments for both dynamics. When the singular perturbation method is applied, the fast dynamic differential equation degenerates to an algebraic equation; the real roots of this equation can be determined by using another bond graph called singularly perturbed bond graph (SPBG). This SPBG has the characteristic that storage elements of the fast state and slow state have a derivative and integral causality assignment, respectively. Thus, a quasi-steady state model by using SPBG is obtained. A Lemma to get the junction structure from SPBG is proposed. Finally, the proposed methodology is applied to two examples.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 483-503
Issue: 5
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2013.766214
File-URL: http://hdl.handle.net/10.1080/13873954.2013.766214
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:5:p:483-503
Template-Type: ReDIF-Article 1.0
Author-Name: J. Sabatier
Author-X-Name-First: J.
Author-X-Name-Last: Sabatier
Author-Name: H. Nguyen
Author-X-Name-First: H.
Author-X-Name-Last: Nguyen
Author-Name: X. Moreau
Author-X-Name-First: X.
Author-X-Name-Last: Moreau
Author-Name: A. Oustaloup
Author-X-Name-First: A.
Author-X-Name-Last: Oustaloup
Title: Fractional behaviour of partial differential equations whose coefficients are exponential functions of the space variable
Abstract:
There exists a close link between fractional systems and infinite dimensional systems described by diffusion equations. This link can be demonstrated analytically and is reminded in this article. This fractional behaviour results in fact in the system infinite dimension along with constant geometric characteristics. This article demonstrates that several other classes of differential equations also exhibit, on a frequency band, a fractional behaviour. The fractional behaviour is obtained with these equations on a space of finite dimension but with particular geometric characteristics.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 434-450
Issue: 5
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2013.766805
File-URL: http://hdl.handle.net/10.1080/13873954.2013.766805
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:5:p:434-450
Template-Type: ReDIF-Article 1.0
Author-Name: Yu-Chung Tsao
Author-X-Name-First: Yu-Chung
Author-X-Name-Last: Tsao
Author-Name: Lu-Wen Liao
Author-X-Name-First: Lu-Wen
Author-X-Name-Last: Liao
Author-Name: Pi-Chuan Sun
Author-X-Name-First: Pi-Chuan
Author-X-Name-Last: Sun
Title: Dynamic decision-making for an inventory system with time-varying demand
Abstract:
This article considers the problem of dynamic decision-making for time-varying demand products under trade credit. The article adopts a price, warranty length and time-dependent demand function to model the finite time horizon inventory. The objective of this study is to determine the optimal periodic selling price, warranty length and ordering quantity so that the total profit is maximized. We discuss the optimization properties and develop solution procedures based on dynamic programming techniques for solving the problem described. The numerical analyses show that dynamic decision-making is superior to fixed decision-making and an appropriate warranty policy can benefit the company. This study also discusses the effects of interest earned, interest charged and credit period on company's decisions and profits.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 401-416
Issue: 5
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2013.777747
File-URL: http://hdl.handle.net/10.1080/13873954.2013.777747
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:5:p:401-416
Template-Type: ReDIF-Article 1.0
Author-Name: Tina Schuetz
Author-X-Name-First: Tina
Author-X-Name-Last: Schuetz
Author-Name: Stefan Becker
Author-X-Name-First: Stefan
Author-X-Name-Last: Becker
Author-Name: Andreas Mang
Author-X-Name-First: Andreas
Author-X-Name-Last: Mang
Author-Name: Alina Toma
Author-X-Name-First: Alina
Author-X-Name-Last: Toma
Author-Name: Thorsten Buzug
Author-X-Name-First: Thorsten
Author-X-Name-Last: Buzug
Title: Modelling of glioblastoma growth by linking a molecular interaction network with an agent-based model
Abstract:
In this work, a mathematical model of malignant brain tumour growth is presented. In particular, the growth of glioblastoma is investigated on the intracellular and intercellular scale.The Go or Grow principle of tumour cells states that tumour cells either migrate or proliferate. For glioblastoma, microRNA-451 has been shown to be an energy dependent key regulator of the LKB1 (liver kinase B1) and AMPK (AMP-activated protein kinase) pathway that influences the signalling for migration or cell division.We introduce a mathematical model that reproduces these biological processes. The intracellular molecular interaction network is represented by a system of nine ordinary differential equations. This is put into a multiscale context by applying an agent-based approach: each cell is equipped with this interaction network and additional rules to determine its new phenotype as either migrating, proliferating or quiescent.The evaluation of the proposed model by comparison of the results with in vitro experiments indicates its validity.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 417-433
Issue: 5
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2013.777748
File-URL: http://hdl.handle.net/10.1080/13873954.2013.777748
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:5:p:417-433
Template-Type: ReDIF-Article 1.0
Author-Name: Martin Benedikt
Author-X-Name-First: Martin
Author-X-Name-Last: Benedikt
Author-Name: Daniel Watzenig
Author-X-Name-First: Daniel
Author-X-Name-Last: Watzenig
Author-Name: Anton Hofer
Author-X-Name-First: Anton
Author-X-Name-Last: Hofer
Title: Modelling and analysis of the non-iterative coupling process for co-simulation
Abstract:
Concerning non-iterative co-simulation, stepwise extrapolation of coupling signals is required to solve an overall system of interconnected subsystems. Each extrapolation is some kind of estimation and is directly associated with an estimation error. The introduced disturbance depends significantly on the macro-step size, i.e. the coupling step size, and influences the entire system behaviour. In addition, for synchronization purposes, sampling of the coupling signals can cause aliasing. Instead of analysing the coupling effects in the time domain, as it is commonly practised, we concentrate on a model-based approach to gain more insight into the coupling process. In this work, we consider commonly used polynomial extrapolation techniques and analyse them in the frequency domain. Based on this system-oriented point of view of the coupling process, a relation between the coupling signals and the macro-step size is available. In accordance to the dynamics of the interconnected subsystems, the model-based relation is used to select the most critical parameter, i.e. the macro-step size. Besides a ‘rule of thumb’ for meaningful step-size selection, a co-simulation benchmark example describing a two degree of freedom (2-DOF) mechanical system is used to demonstrate the advantages of modelling and the efficiency of the proposed method.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 451-470
Issue: 5
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2013.784340
File-URL: http://hdl.handle.net/10.1080/13873954.2013.784340
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:5:p:451-470
Template-Type: ReDIF-Article 1.0
Author-Name: K. Dedecius
Author-X-Name-First: K.
Author-X-Name-Last: Dedecius
Author-Name: V. Sečkárová
Author-X-Name-First: V.
Author-X-Name-Last: Sečkárová
Title: Centralized Bayesian reliability modelling with sensor networks
Abstract:
The article concerns reliability estimation in modern dynamic systems. It introduces a novel approach, exploiting a network of several independent spatially distributed sensors, actively probing the monitored system. A dedicated network element – the fusion centre – is then responsible for processing the information provided by sensors and evaluation of final reliability estimate. On the base of computational abilities of sensors, we propose two conceptually different reliability estimation scenarios: (1) the computationally cheaper dummy sensors scenario, in which the sensors send raw data to the fusion centre; and (2) the smart sensors scenario, when the data are processed locally by sensors, and the fusion centre subsequently merges their resulting information. The local processing allows to obtain ‘low-level’ reliability estimate from a particular sensor, which is of interest in large networks with communication constraints. In both cases, the emphasis is put on recursiveness, adaptivity and robustness of solutions. The Bayesian paradigm was adopted for consistent information representation, its adaptive dynamic processing and fusion.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 471-482
Issue: 5
Volume: 19
Year: 2013
X-DOI: 10.1080/13873954.2013.789064
File-URL: http://hdl.handle.net/10.1080/13873954.2013.789064
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Handle: RePEc:taf:nmcmxx:v:19:y:2013:i:5:p:471-482
Template-Type: ReDIF-Article 1.0
Author-Name: H. Penasso
Author-X-Name-First: H.
Author-X-Name-Last: Penasso
Author-Name: S. Thaller
Author-X-Name-First: S.
Author-X-Name-Last: Thaller
Title: Determination of individual knee-extensor properties from leg extensions and parameter identification
Abstract:
Neural commands control skeletal muscles that act on passive structures and regulate voluntary movements. Mathematical models can simulate such movements and therefore require the knowledge of neuromuscular properties. In contrast to scaling these properties to the individual, we present a non-linear parameter identification method to determine them non-invasively and in vivo. The classic model A describes an excitable contractile element (CE) embedded in a geometrical representation of the leg. Its extension model B is used to study the effects of the force–length relationship and the serial elastic element (SEE). We show the validation of model B and discuss the quality of neuromuscular properties identified from simulations and experiments. The main finding is that identifications that consider CE–SEE dynamics result in increased and more realistic curvatures of the force–velocity relations. This shows that CE and SEE work interdependently and we recommend to co-ordinate the parameter values of muscle–tendon units.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 416-438
Issue: 4
Volume: 23
Year: 2017
Month: 7
X-DOI: 10.1080/13873954.2017.1336633
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1336633
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:4:p:416-438
Template-Type: ReDIF-Article 1.0
Author-Name: T. Hoch
Author-X-Name-First: T.
Author-X-Name-Last: Hoch
Author-Name: X. Tan
Author-X-Name-First: X.
Author-X-Name-Last: Tan
Author-Name: R. Leser
Author-X-Name-First: R.
Author-X-Name-Last: Leser
Author-Name: A. Baca
Author-X-Name-First: A.
Author-X-Name-Last: Baca
Author-Name: B. A. Moser
Author-X-Name-First: B. A.
Author-X-Name-Last: Moser
Title: A knowledge discovery framework for the assessment of tactical behaviour in soccer based on spatiotemporal data
Abstract:
This paper addresses the problem of designing an explanatory computational model for the assessment of individual tactic skills in team sports. The modelling approach tackles the complexity and difficulty of this problem by fusing fuzzy human-like knowledge related to tactical behaviour with time-continuous position data from a tracking system. For this purpose, a hierarchical architecture is proposed. The bottom layer is represented by physically meaningful variables derived from time-continuous position data at specific time instances. Based thereupon, we introduce a temporal segmentation layer that relates the physical variables to game-situation-specific temporal phases. We show how the vague and imprecisely defined linguistic description of the task at hand can be transferred to fuzzy rules in order to get a meaningful temporal segmentation of the time-continuous position data. Finally, the resulting clusters are interpreted in terms of performance indicators in the top layer in order to provide a meaningful explanatory model for the assessment. We show the usefulness of our approach for the task of player evaluation. We do not only provide the coach with a single number to describe the players’ performance but also relate this number to the measurement variables, presenting a more holistic and sophisticated view of the players’ performance.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 384-398
Issue: 4
Volume: 23
Year: 2017
Month: 7
X-DOI: 10.1080/13873954.2017.1336634
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1336634
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:4:p:384-398
Template-Type: ReDIF-Article 1.0
Author-Name: Michael Stöckl
Author-X-Name-First: Michael
Author-X-Name-Last: Stöckl
Author-Name: Denise Plück
Author-X-Name-First: Denise
Author-X-Name-Last: Plück
Author-Name: Martin Lames
Author-X-Name-First: Martin
Author-X-Name-Last: Lames
Title: Modelling game sports as complex systems – application of recurrence analysis to golf and soccer
Abstract:
Analyses of game sports or of performances shown in them require appropriate models. Many game sports can be modelled as complex, dynamic systems. This study investigated how recurrence plots (RPs) – a method to analyse complex systems – and the analyses of RPs can be applied to the game sports golf and soccer. A golfer is treated as a complex system with many unknown components. The scalar variable Shots Saved can describe his/her behaviour. Phase space reconstruction is needed to unfold hidden facets of a golfer’s behaviour. Results indicate that golfers’ performances do not approach a stable state, but seem rather unpredictable. A soccer match can also be treated as a complex system. Some components – the players – and their respective behaviour represented by movement trajectories are known and can be used to describe the system’s behaviour. We propose that no embedding is needed for the RP construction in this case. Results indicate that the more goal shots there are in a game, the more unstructured it is. Furthermore, if several golfers or soccer matches are investigated, we recommend using the same RP parameters to achieve comparable results.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 399-415
Issue: 4
Volume: 23
Year: 2017
Month: 7
X-DOI: 10.1080/13873954.2017.1336635
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1336635
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:4:p:399-415
Template-Type: ReDIF-Article 1.0
Author-Name: Arnold Baca
Author-X-Name-First: Arnold
Author-X-Name-Last: Baca
Title: Mathematical modelling in sport and human movement science
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 361-362
Issue: 4
Volume: 23
Year: 2017
Month: 7
X-DOI: 10.1080/13873954.2017.1336636
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1336636
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:4:p:361-362
Template-Type: ReDIF-Article 1.0
Author-Name: Bartholomew Spencer
Author-X-Name-First: Bartholomew
Author-X-Name-Last: Spencer
Author-Name: Sam Robertson
Author-X-Name-First: Sam
Author-X-Name-Last: Robertson
Author-Name: Stuart Morgan
Author-X-Name-First: Stuart
Author-X-Name-Last: Morgan
Title: Modelling within-team relative phase couplings using position derivatives in Australian rules football
Abstract:
Several approaches to the modelling of interpersonal movement coordination in sports, inspired by dynamical systems, have leveraged relative proximity to fixed ground points, such as the court midline to represent the phasic characteristics of movement in competition. While these approaches are useful in highly constrained sports such as tennis and squash, Australian football (AF) is played on a much larger playing area (approximately 150 m × 100 m) and is characterized by a ‘rolling scrum’ of interpersonal contests. Consequently, a different approach to modelling pairwise movement coordination is required. We propose a method that encodes interpersonal movement coordination using relative phase properties derived from angular velocity and acceleration. We demonstrate that these properties encode the level of temporal alignment of changes in running speed and direction between player pairs. This approach is illustrated using exemplar data from AF and explores net pairwise movement coordination within and between teams, and as a function of match duration.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 372-383
Issue: 4
Volume: 23
Year: 2017
Month: 7
X-DOI: 10.1080/13873954.2017.1336732
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1336732
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:4:p:372-383
Template-Type: ReDIF-Article 1.0
Author-Name: Norbert Schrapf
Author-X-Name-First: Norbert
Author-X-Name-Last: Schrapf
Author-Name: Shaimaa Alsaied
Author-X-Name-First: Shaimaa
Author-X-Name-Last: Alsaied
Author-Name: Markus Tilp
Author-X-Name-First: Markus
Author-X-Name-Last: Tilp
Title: Tactical interaction of offensive and defensive teams in team handball analysed by artificial neural networks
Abstract:
The interaction between teams behaviour is from high relevance for success in sports games. Since the analysis of this interaction is not well established, the present study attempts to model the interaction between opposing teams in team handball. Offensive and defensive playing patterns were determined by means of artificial neural networks from position data of 723 offensive action sequences and the corresponding defensive players, respectively. The most common combinations of these patterns were then analysed statistically. Pattern efficiency was assessed by scoring rate, distance between shooting position and nearest defensive player and distance to goal. No statistically significant relation between pattern combinations and efficiency was found. However, results revealed tendencies to higher efficiency of some tactical patterns. Furthermore, odds ratio analysis revealed advantageous defensive tactics against specific offensive behaviour. Summarizing, results indicate that artificial neural networks are appropriate to model the interaction between teams based on players’ positions.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 363-371
Issue: 4
Volume: 23
Year: 2017
Month: 7
X-DOI: 10.1080/13873954.2017.1336733
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1336733
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Handle: RePEc:taf:nmcmxx:v:23:y:2017:i:4:p:363-371
Template-Type: ReDIF-Article 1.0
Author-Name: David J. Murray-Smith
Author-X-Name-First: David J.
Author-X-Name-Last: Murray-Smith
Title: Inverse simulation and analysis of underwater vehicle dynamics using feedback principles
Abstract:
Inverse simulation is a technique used in the modelling of dynamic systems that allows time histories of input variables to be found that generate required model output responses and provide inverse solutions in cases where analytical approaches to model inversion can present difficulties. This paper describes the application of inverse simulation to a nonlinear dynamic model of an unmanned underwater vehicle (UUV) and the determination of vehicle control inputs for specified manoeuvres. The approach to inverse simulation used in this application is based on the principles of feedback. Design issues relating to the UUV control surfaces and propeller thrust are highlighted through this procedure. The paper includes an outline of the nonlinear model of the UUV and typical sets of experimental conditions. Feedback loops are designed around the model for selected output variables and the inverse solutions are generated through simulation of this multi-input multi-output closed-loop system. It is shown that the feedback approach can provide inverse solutions for an appropriate choice of loop-gain factors and integration time step using a fixed-step integration algorithm. Inverse solutions generated in this way are shown to provide insight concerning issues of vehicle handling and manoeuvrability in a more direct fashion than is possible using conventional simulation methods.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 45-65
Issue: 1
Volume: 20
Year: 2014
Month: 1
X-DOI: 10.1080/13873954.2013.805146
File-URL: http://hdl.handle.net/10.1080/13873954.2013.805146
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:1:p:45-65
Template-Type: ReDIF-Article 1.0
Author-Name: Gianni Ferretti
Author-X-Name-First: Gianni
Author-X-Name-Last: Ferretti
Author-Name: Alberto Leva
Author-X-Name-First: Alberto
Author-X-Name-Last: Leva
Author-Name: Bruno Scaglioni
Author-X-Name-First: Bruno
Author-X-Name-Last: Scaglioni
Title: Object-oriented modelling of general flexible multibody systems
Abstract:
This paper presents a general approach to object-oriented modelling of flexible multibody systems, based on the floating frame of reference (FFR) formulation. The data describing a flexible body can be computed analytically, having defined its shape functions matrices, or calculated by several finite element method (FEM) packages as a result of a modal analysis. By the proposed approach, a modular model is then obtained in an object-oriented language, namely Modelica. This allows to integrate very realistic descriptions of distributed flexibility in multidomain models, with significant advantages for a variety of simulation studies. After describing the general methodology, the paper presents some simulation results, to validate the approach with respect to benchmark cases considered in the literature.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 1-22
Issue: 1
Volume: 20
Year: 2014
Month: 1
X-DOI: 10.1080/13873954.2013.807433
File-URL: http://hdl.handle.net/10.1080/13873954.2013.807433
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:1:p:1-22
Template-Type: ReDIF-Article 1.0
Author-Name: Katrin Speicher
Author-X-Name-First: Katrin
Author-X-Name-Last: Speicher
Author-Name: Andreas Steinboeck
Author-X-Name-First: Andreas
Author-X-Name-Last: Steinboeck
Author-Name: Daniel Wild
Author-X-Name-First: Daniel
Author-X-Name-Last: Wild
Author-Name: Thomas Kiefer
Author-X-Name-First: Thomas
Author-X-Name-Last: Kiefer
Author-Name: Andreas Kugi
Author-X-Name-First: Andreas
Author-X-Name-Last: Kugi
Title: An integrated thermal model of hot rolling
Abstract:
During the heavy plate rolling process, different production steps, i.e., roll passes, descaling passes, and air cooling periods, influence the temperature evolution of the plate. All these relevant aspects are covered by a one-dimensional thermal model proposed in this paper. Experiments were conducted in a rolling mill under realistic rolling conditions to parametrise and validate the model. Using pyrometer measurements, a simple model adaption strategy is developed, which can cope with uncertainties in the initial temperature profile. The model provides accurate predictions of the temperature evolution of the plate during the whole rolling process from the plate’s exit of the furnace to the last pass. Thus, it can be used for scheduling the production process. Based on the model, an observer can be designed.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 66-86
Issue: 1
Volume: 20
Year: 2014
Month: 1
X-DOI: 10.1080/13873954.2013.809364
File-URL: http://hdl.handle.net/10.1080/13873954.2013.809364
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:1:p:66-86
Template-Type: ReDIF-Article 1.0
Author-Name: Susanne V. Krichel
Author-X-Name-First: Susanne V.
Author-X-Name-Last: Krichel
Author-Name: Oliver Sawodny
Author-X-Name-First: Oliver
Author-X-Name-Last: Sawodny
Title: Non-linear friction modelling and simulation of long pneumatic transmission lines
Abstract:
Dynamic modelling and numerical implementation strategies for fluid transmission lines have been studied thoroughly, mainly for the application in hydraulic pipeline networks. Recent interest in energy efficiency has seen a resurgence of this field for compressed air networks, with impact on manufacturing processes, simulation of pneumatic drive components, and other theoretical analysis applications. The effects of long tubes connecting system components are often neglected to increase computational speed and reduce model size. This document highlights existing modelling approaches from practice as well as from fluid dynamic theory. Existing approaches for hydraulic transmission lines are adapted to their use for pneumatic tubes. A low-order model is derived capable to predict the transient behaviour of pressure and mass flow rate distribution within the tube. The model accounts for non-linear turbulent flow conditions, and is designed to be compatible with signal-flow simulation programmes, increasing its usability in large-scale industrial settings. It is numerically well conditioned, and all parameters are determined by physical or empirical relationships. Both its transient and quasi-stationary behaviour are validated against experimental results.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 23-44
Issue: 1
Volume: 20
Year: 2014
Month: 1
X-DOI: 10.1080/13873954.2013.811268
File-URL: http://hdl.handle.net/10.1080/13873954.2013.811268
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:1:p:23-44
Template-Type: ReDIF-Article 1.0
Author-Name: M. Sbarciog
Author-X-Name-First: M.
Author-X-Name-Last: Sbarciog
Author-Name: A. Vande Wouwer
Author-X-Name-First: A.
Author-X-Name-Last: Vande Wouwer
Title: Start-up of multi-species anaerobic digestion systems: extrapolation of the single species approach
Abstract:
This paper presents a brief evaluation of a start-up strategy for multi-species anaerobic digestion systems modelled as two-step reaction systems, where acidogenesis is described by Monod kinetics while the methanogenesis is described by Haldane kinetics. The start-up policy has been developed originally for single species systems with the aim of maximizing the biogas outflow rate. It consists of switching the dilution rate from minimum to maximum and then to the optimal value (bang-bang control) in order to bring the system from an arbitrary initial condition to the optimal set-point. This start-up strategy is applied to the multi-species system using an averaged model, which is usually the only model that can be identified for a multi-species system, as measuring individual biomasses is almost impossible in practice. Even the development of an accurate averaged model, fully characterizing the system dynamics based on the variation of the species proportions is difficult. The averaged models used in this study are built based on a more or less accurate knowledge of the species proportions and their kinetics at the start-up instant and used as such in the application of the start-up policy. It is shown that the start-up policy leads to an efficient ecosystem, characterized by high outflow rate of biogas, which is very close to the maximum even in the case of an inaccurate averaged model. The influence of the model accuracy on the system stability and its productivity is discussed. This study can also be viewed as a robustness evaluation with respect to model inaccuracy of the single species start-up strategy, as the process changes from the averaged kinetics to the kinetics of the winning species during species selection.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 87-104
Issue: 1
Volume: 20
Year: 2014
Month: 1
X-DOI: 10.1080/13873954.2013.817443
File-URL: http://hdl.handle.net/10.1080/13873954.2013.817443
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Handle: RePEc:taf:nmcmxx:v:20:y:2014:i:1:p:87-104
Template-Type: ReDIF-Article 1.0
Author-Name: H. Ghafarirad
Author-X-Name-First: H.
Author-X-Name-Last: Ghafarirad
Author-Name: S.M. Rezaei
Author-X-Name-First: S.M.
Author-X-Name-Last: Rezaei
Author-Name: Ahmed A.D. Sarhan
Author-X-Name-First: Ahmed A.D.
Author-X-Name-Last: Sarhan
Author-Name: M. Zareinejad
Author-X-Name-First: M.
Author-X-Name-Last: Zareinejad
Title: Continuous dynamic modelling of bimorph piezoelectric cantilevered actuators considering hysteresis effect and dynamic behaviour analysis
Abstract:
Bimorph Piezoelectric Cantilevered (BPC) actuators have been of increasing interest in micro-manipulation processes during recent years. Due to properties such as transverse vibration, the performance and manoeuvrability have considerably improved, compared with conventional longitudinal piezoelectric actuators. Therefore, dynamic modelling of such actuators has been the centre of attraction. For this purpose, a target point on the actuator, e.g. the cantilever end tip, is usually considered as the actuator output. One degree of freedom lumped and continuous type dynamic models have been considered in prior research works. These types of modelling lead to two significant issues. First, the effect of higher vibrational modes in the actuator output is disregarded. Second, a minimum phase dynamic system is achievable for all target points regardless of position. In this paper, these two issues will be analytically and experimentally investigated. To this end, a linear continuous dynamic model for a general BPC actuator is derived and discretized by attaining exact mode shapes. The Prandtl–Ishlinskii (PI) model is utilized to model and identify the non-linear hysteresis behaviour. In contrast to previous works, dynamic behaviour analysis elaborates on the effect of higher modes in the actuator output response. In addition, the possibility of non-minimum phase behaviour based on the location of the target point is investigated. Simulation studies and experimental results confirm the validity of the proposed dynamic model and its behaviour analysis.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 130-152
Issue: 2
Volume: 21
Year: 2015
Month: 3
X-DOI: 10.1080/13873954.2014.906472
File-URL: http://hdl.handle.net/10.1080/13873954.2014.906472
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:2:p:130-152
Template-Type: ReDIF-Article 1.0
Author-Name: Bing Wang
Author-X-Name-First: Bing
Author-X-Name-Last: Wang
Author-Name: Bo Deng
Author-X-Name-First: Bo
Author-X-Name-Last: Deng
Author-Name: Fei Xing
Author-X-Name-First: Fei
Author-X-Name-Last: Xing
Author-Name: Dongxia Wang
Author-X-Name-First: Dongxia
Author-X-Name-Last: Wang
Author-Name: Yiping Yao
Author-X-Name-First: Yiping
Author-X-Name-Last: Yao
Title: Partitioned event graph: formalizing LP-based modelling of parallel discrete-event simulation
Abstract:
Logical process (LP) is a modelling paradigm widely used in parallel discrete-event simulation (PDES). However, effective methods for formalizing LP-based modelling of PDES are lacking. This prevents an unambiguous, platform-independent description of LP-based models. We present a formalism named partitioned event graph (PEG) as a solution. PEG extends classical event graph formalism towards a formal specification for LP-based PDES models. We map between PEG and LP-based models, define the structural operational semantics (SOS) in a timed-labelled transition system, and discuss the Wallclock time-based execution. We propose a PEG-based model transformation framework for PDES, which has three model representation phases and distinguishes amongst four kinds of personnel roles. Finally, we present a domain-specific language (DSL) for the PDES of a Lotka–Volterra system and obtain preliminary parallel simulation results using YinHe Simulation Utilities for Parallel Environment (YHSUPE). The case study shows that the PEG-based framework not only effectively transforms a DSL into the LP paradigm, but will also result in efficient parallel simulation on a specific platform. In summary, by setting out specific characteristics for event scheduling and state space partition in the LP paradigm, PEG provides a formal method for model behaviour analysis and cross-platform model transformation.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 153-179
Issue: 2
Volume: 21
Year: 2015
Month: 3
X-DOI: 10.1080/13873954.2014.911750
File-URL: http://hdl.handle.net/10.1080/13873954.2014.911750
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:2:p:153-179
Template-Type: ReDIF-Article 1.0
Author-Name: Angelika Bruns
Author-X-Name-First: Angelika
Author-X-Name-Last: Bruns
Author-Name: Peter Benner
Author-X-Name-First: Peter
Author-X-Name-Last: Benner
Title: Parametric model order reduction of thermal models using the bilinear interpolatory rational Krylov algorithm
Abstract:
The Bilinear Interpolatory Rational Krylov Algorithm (BIRKA; P. Benner and T. Breiten, Interpolation-based H2-model reduction of bilinear control systems, SIAM J. Matrix Anal. Appl. 33 (2012), pp. 859–885. doi:10.1137/110836742) is a recently developed method for Model Order Reduction (MOR) of bilinear systems. Here, it is used and further developed for a certain class of parametric systems. As BIRKA does not preserve stability, two different approaches generating stable reduced models are presented. In addition, the convergence for a modified version of BIRKA for large systems is analysed and a method for detecting divergence possibly resulting from this modification is proposed. The behaviour of the algorithm is analysed using a finite element model for the thermal analysis of an electrical motor. The reduction of two different motor models, incorporating seven and thirteen different physical parameters, is performed.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 103-129
Issue: 2
Volume: 21
Year: 2015
Month: 3
X-DOI: 10.1080/13873954.2014.924534
File-URL: http://hdl.handle.net/10.1080/13873954.2014.924534
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:2:p:103-129
Template-Type: ReDIF-Article 1.0
Author-Name: J. Henikl
Author-X-Name-First: J.
Author-X-Name-Last: Henikl
Author-Name: W. Kemmetmüller
Author-X-Name-First: W.
Author-X-Name-Last: Kemmetmüller
Author-Name: M. Bader
Author-X-Name-First: M.
Author-X-Name-Last: Bader
Author-Name: A. Kugi
Author-X-Name-First: A.
Author-X-Name-Last: Kugi
Title: Modelling, simulation and identification of a mobile concrete pump
Abstract:
Due to the light-weight construction of modern large-scale manipulators used, e.g., in mobile concrete pumps, the elasticity of the construction elements plays a significant role in the dynamic behaviour of the system. Therefore, current research is concerned with control strategies for active damping of elastic vibrations and trajectory planning. For this purpose, tailored mathematical models are required. Apart from the mathematical modelling, the identification of the model parameters constitutes a challenging task. This is mainly due to the large number of parameters to be identified and, considering the large scale, due to the fact that the boom movement cannot be measured by means of standard sensors. This paper presents a systematic approach for the mathematical modelling and identification of hydraulically actuated large-scale manipulators. The feasibility of the overall approach is demonstrated by means of measurement results of a mobile concrete pump.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 180-201
Issue: 2
Volume: 21
Year: 2015
Month: 3
X-DOI: 10.1080/13873954.2014.926277
File-URL: http://hdl.handle.net/10.1080/13873954.2014.926277
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Handle: RePEc:taf:nmcmxx:v:21:y:2015:i:2:p:180-201
Template-Type: ReDIF-Article 1.0
Author-Name: Nita H. Shah
Author-X-Name-First: Nita H.
Author-X-Name-Last: Shah
Author-Name: Mrudul Y. Jani
Author-X-Name-First: Mrudul Y.
Author-X-Name-Last: Jani
Author-Name: Urmila Chaudhari
Author-X-Name-First: Urmila
Author-X-Name-Last: Chaudhari
Title: Optimal replenishment time for retailer under partial upstream prepayment and partial downstream overdue payment for quadratic demand
Abstract:
In competitive edge, the proffer of delay payment is of great consequence tool to boost the market demand by exerting influence of more customers. In opposition to, merchandiser may be asked to pay some per cent of purchasing cost before receiving products to reduce the risk of cancellation of order. In this article, optimal replenishment time for merchandiser under partial upstream prepayment and partial downstream overdue payment is presented under quadratic demand with three different models: (1) without deterioration, (2) with constant deterioration and (3) maximum fixed-lifetime deterioration as loss of utility is the real situation of products like fruits, vegetables, juices, etc., and to reduce deterioration of the product, merchandiser spends capital on preservation technology to preserve the item. Quadratic demand is suitable for the products for which demand increases initially and afterward it starts to decrease. The decision policies are analysed for the merchandiser. The objective is to minimize merchandiser’s total cost with respect to decision variables. The models are supported with numerical examples. Sensitivity analysis is carried out to derive insights for decision maker.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 1-11
Issue: 1
Volume: 24
Year: 2018
Month: 1
X-DOI: 10.1080/13873954.2017.1324882
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1324882
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:1:p:1-11
Template-Type: ReDIF-Article 1.0
Author-Name: Konstantin Belyaev
Author-X-Name-First: Konstantin
Author-X-Name-Last: Belyaev
Author-Name: Andrey Kuleshov
Author-X-Name-First: Andrey
Author-X-Name-Last: Kuleshov
Author-Name: Natalia Tuchkova
Author-X-Name-First: Natalia
Author-X-Name-Last: Tuchkova
Author-Name: Clemente A.S. Tanajura
Author-X-Name-First: Clemente A.S.
Author-X-Name-Last: Tanajura
Title: An optimal data assimilation method and its application to the numerical simulation of the ocean dynamics
Abstract:
An original data assimilation (DA) scheme with a general dynamics model is considered. It is shown that this scheme can be approximated by the stochastic diffusion process. The sufficient conditions to provide this approximation are formulated. Based on this algorithm a new DA method is developed. The method combines variational and statistical approaches commonly used in DA theory and minimizes the variance of the trajectory of a diffusion process in conjunction with a dynamics numerical model. In this sense the method is optimal in contrast to other DA approaches. The proposed scheme takes the model dynamics into account and in this way it differs from the well-known Kalman filter. Furthermore, the derived DA method can be applied to a very wide field of dynamical systems, for example, gas dynamics, fluid dynamics and other disciplines. However, the current study deals with oceanography and DA in oceanography specifically. Then the method is applied to the HYbrid Coordinate Ocean Model and assimilates satellite sea level anomaly data from the Archiving, Validating and Interpolating Satellite Oceanography Data over the Atlantic Ocean to correct the model state. Several numerical experiments have been performed. The experiments show that the method substantially changes the synoptic and mesoscale structure of ocean dynamics. Also, the distribution of the obtained result is estimated through the solution of the Fokker–Planck–Kolmogorov equation.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 12-25
Issue: 1
Volume: 24
Year: 2018
Month: 1
X-DOI: 10.1080/13873954.2017.1338300
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1338300
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:1:p:12-25
Template-Type: ReDIF-Article 1.0
Author-Name: John F. Moxnes
Author-X-Name-First: John F.
Author-X-Name-Last: Moxnes
Author-Name: Øyvind Sandbakk
Author-X-Name-First: Øyvind
Author-X-Name-Last: Sandbakk
Title: Mathematical modelling of the oxygen uptake kinetics during whole-body endurance exercise and recovery
Abstract:
In this study, we elucidate four different mathematical models of the kinetics of oxygen uptake during whole-body endurance exercise at different intensities and throughout the subsequent recovery periods. We employ the hypothetical inductive–deductive method and forecast four different models for the oxygen kinetic. The VO2 development using these models compared with experimental results where an elite cross-country skier performed laboratory tests while running with poles on a treadmill, in which the rate of oxygen uptake and blood lactate concentration as a function of time were measured. The most developed model accounted for the delayed superimposed slow component of oxygen uptake and the influence of lactic power production on the oxygen kinetics. The rate of change in oxygen with this model is consistent with the accumulated oxygen deficit model and matched the data well, even for intensities above the lactate threshold and during recovery.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 76-86
Issue: 1
Volume: 24
Year: 2018
Month: 1
X-DOI: 10.1080/13873954.2017.1348364
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1348364
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:1:p:76-86
Template-Type: ReDIF-Article 1.0
Author-Name: Samah Ben Atia
Author-X-Name-First: Samah
Author-X-Name-Last: Ben Atia
Author-Name: Anis Messaoud
Author-X-Name-First: Anis
Author-X-Name-Last: Messaoud
Author-Name: Ridha Ben Abdennour
Author-X-Name-First: Ridha
Author-X-Name-Last: Ben Abdennour
Title: An online identification algorithm of unknown time-varying delay and internal multimodel control for discrete non-linear systems
Abstract:
In this paper, an online algorithm is proposed for the identification of unknown time-varying input delay in the case of discrete non-linear systems described by decoupled multimodel. This method relies on the minimization of a performance index based on the error between the real system and the partial internal models outputs. In addition, a decoupled internal multimodel control is proposed for the compensation of discrete non-linear systems with time-varying delay. This control scheme incorporates partial internal model controls. Each partial controller is associated to a specified operating zone of the non-linear system. The switching between these controllers is ensured by a supervisor that contains a set of local predictors. A simulation example is carried out to illustrate the significance of the proposed time-varying delay identification algorithm and the proposed internal multimodel control scheme.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 26-43
Issue: 1
Volume: 24
Year: 2018
Month: 1
X-DOI: 10.1080/13873954.2017.1352607
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1352607
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:1:p:26-43
Template-Type: ReDIF-Article 1.0
Author-Name: E.M. Navarro-López
Author-X-Name-First: E.M.
Author-X-Name-Last: Navarro-López
Author-Name: M.D. O’Toole
Author-X-Name-First: M.D.
Author-X-Name-Last: O’Toole
Title: Automated generation of hybrid automata for multi-rigid-body mechanical systems and its application to the falsification of safety properties
Abstract:
What if we designed a tool to automatically generate a dynamical transition system for the formal specification of mechanical systems subject to multiple impacts, contacts and discontinuous friction? Such a tool would represent an advance in the description and simulation of these complex systems. This is precisely what this paper offers: Dyverse Rigid Body Toolbox (DyverseRBT). This tool requires a sufficiently expressive computational model that can accurately describe the behaviour of the system as it evolves over time. For this purpose, we propose an alternative abstraction of multi-rigid-body (MRB) mechanical systems with multiple contacts as an extended version of the classical hybrid automaton, which we call MRB hybrid automaton. One of the chief characteristics of the MRB hybrid automaton is the inclusion of computation nodes to encode algorithms to calculate the contact forces. The computation nodes consist of a set of non-dynamical discrete locations, discrete transitions and guards between these locations, and resets on transitions. They can account for the energy transfer not explicitly considered within the rigid-body formalism. The proposed modelling framework is well suited for the automated verification of dynamical properties of realistic mechanical systems. We show this by the falsification of safety properties over the transition system generated by DyverseRBT.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 44-75
Issue: 1
Volume: 24
Year: 2018
Month: 1
X-DOI: 10.1080/13873954.2017.1369437
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1369437
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:1:p:44-75
Template-Type: ReDIF-Article 1.0
Author-Name: Behnaz Seyfi Noferest
Author-X-Name-First: Behnaz
Author-X-Name-Last: Seyfi Noferest
Author-Name: Anand P. Santhanam
Author-X-Name-First: Anand P.
Author-X-Name-Last: Santhanam
Author-Name: Olusegun J. Ilegbusi
Author-X-Name-First: Olusegun J.
Author-X-Name-Last: Ilegbusi
Title: Effect of gravity on subject-specific human lung deformation
Abstract:
A biomechanical model of human lung is developed and used to investigate the effect of gravity on lung deformation. The lung is assumed to behave as a poro-elastic medium with spatially dependent elastic property. Finite element analysis is performed on a three-dimensional (3D) lung geometry reconstructed from a four-dimensional Computed Tomography (4DCT) scan dataset of human patient. The spatially dependent Young’s modulus (YM) values are estimated using inverse analysis from a linear elastic deformation model. The predicted deformation of selected landmarks is monitored with and without gravity, and compared with data obtained from 4DCT registration. The results show that gravity indeed significantly affects the magnitude and distribution of lung deformation with the maximum displacement enhanced by 54% in the direction of gravity, for the conditions investigated. In summary, the accuracy of predicted deformation is improved through incorporation of gravity in the biomechanical model of lung.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 87-101
Issue: 1
Volume: 24
Year: 2018
Month: 1
X-DOI: 10.1080/13873954.2017.1382537
File-URL: http://hdl.handle.net/10.1080/13873954.2017.1382537
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Handle: RePEc:taf:nmcmxx:v:24:y:2018:i:1:p:87-101
Template-Type: ReDIF-Article 1.0
Author-Name: S. H. Sabzpoushan
Author-X-Name-First: S. H.
Author-X-Name-Last: Sabzpoushan
Author-Name: A. Ghajarjazy
Author-X-Name-First: A.
Author-X-Name-Last: Ghajarjazy
Title: A method for reduction of human ventricular action potential model
Abstract:
Mathematical modelling and computer simulations are important tools in the field of cardiac electrophysiology. High computational costs of complex models make them difficult to apply in large-scale simulations like tissue. Therefore, model reduction are of particular importance in heart studies. In this paper, we introduce a technique for simplification of ventricular cell(VC) complex models. By using this technique, starting with a complex model of human VC including 17state variables, we reduce the number of state variables to two. Our simplified model is compared with the original one via several electrophysiological features and computational efficiency. Results show that the reduced model has acceptable behaviours in single cell and one-dimensional simulation, moreover, is 55 times faster than the original one. As the presented method does not depend on the reference model, it may be applied to every cardiac cell models or each complex excitable dynamical systems with the same dynamics as VC.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 1-30
Issue: 1
Volume: 26
Year: 2020
Month: 1
X-DOI: 10.1080/13873954.2019.1701039
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1701039
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:1:p:1-30
Template-Type: ReDIF-Article 1.0
Author-Name: Naige Wang
Author-X-Name-First: Naige
Author-X-Name-Last: Wang
Author-Name: Guohua Cao
Author-X-Name-First: Guohua
Author-X-Name-Last: Cao
Author-Name: Lu Yan
Author-X-Name-First: Lu
Author-X-Name-Last: Yan
Author-Name: Lei Wang
Author-X-Name-First: Lei
Author-X-Name-Last: Wang
Title: Modelling and passive control of flexible guiding hoisting system with time-varying length
Abstract:
A coupled dynamic modelling of the flexible guiding hoisting system is established, which includes the transverse-longitudinal-coupled vibration and the rotational vibration. Substituting vibrational energy of the system into Hamilton principle and applying the dynamic constraint, a distributed parameter mathematical model of the multi-rope system is derived. It is governed by coupled partial differential equations and ordinary differential equations (PDEs-ODEs), where the dynamic constraint in the form of an unknown moving force is the only connection between the hoisting conveyance and the guiding ropes. Based on Galerkin method, the dynamic response of the system is validated by numerical calculation and ADAMS simulation. Besides, an absorber with artificial intelligence optimization is proposed to reduce system vibration. The simulation result has demonstrated that a hoisting conveyance resonance can be observed when the external disturbance frequency is close to the system natural frequencies. Moreover, a vibration absorber can effectively diminish the resonant peaks of the first three orders of the guiding rope.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 31-54
Issue: 1
Volume: 26
Year: 2020
Month: 1
X-DOI: 10.1080/13873954.2019.1699121
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1699121
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:1:p:31-54
Template-Type: ReDIF-Article 1.0
Author-Name: Amirali Sadeqi
Author-X-Name-First: Amirali
Author-X-Name-Last: Sadeqi
Author-Name: Shapour Moradi
Author-X-Name-First: Shapour
Author-X-Name-Last: Moradi
Author-Name: Kourosh Heidari Shirazi
Author-X-Name-First: Kourosh Heidari
Author-X-Name-Last: Shirazi
Title: Detectability conditions for output-only subspace identification
Abstract:
The scope of output-only/blind identification is restricted to stochastic/statistical processes, but for the first time in this study, the detectability conditions for general output-only subspace identification are investigated. This aids the range of input sources to be extended in a much realistic manner, beyond the only stochastic inputs. For this purpose, the subspace framework is assigned to make a connection between the output signal contents and the LTI system order. A few substantial hypotheses and algebraic statements are propounded affirming the sufficiency of the genuine output sequences for the identification purpose. This can be perceived as the cornerstone of state-space model reconstruction. In order to consolidate the notions according to reality, several examples are studied and examined for different input classes with stochastic disturbance.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 55-79
Issue: 1
Volume: 26
Year: 2020
Month: 1
X-DOI: 10.1080/13873954.2019.1701038
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1701038
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:1:p:55-79
Template-Type: ReDIF-Article 1.0
Author-Name: Tusan Derya
Author-X-Name-First: Tusan
Author-X-Name-Last: Derya
Author-Name: Esra Dinler
Author-X-Name-First: Esra
Author-X-Name-Last: Dinler
Author-Name: Barış Keçeci
Author-X-Name-First: Barış
Author-X-Name-Last: Keçeci
Title: Selective generalized travelling salesman problem
Abstract:
This paper introduces the Selective Generalized Traveling Salesman Problem (SGTSP). In SGTSP, the goal is to determine the maximum profitable tour within the given threshold of the tour’s duration, which consists of a subset of clusters and a subset of nodes in each cluster visited on the tour. This problem is a combination of cluster and node selection and determining the shortest path between the selected nodes. We propose eight mixed integer programming (MIP) formulations for SGTSP. All of the given MIP formulations are completely new, which is one of the major novelties of the study. The performance of the proposed formulations is evaluated on a set of test instances by conducting 4608 experimental runs. Overall, 4138 out of 4608 (~90%) test instances were solved optimally by using all formulations.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 80-118
Issue: 1
Volume: 26
Year: 2020
Month: 1
X-DOI: 10.1080/13873954.2019.1705496
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1705496
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:1:p:80-118
Template-Type: ReDIF-Article 1.0
Author-Name: Sabah Ahmed Abdul-Wahab
Author-X-Name-First: Sabah Ahmed
Author-X-Name-Last: Abdul-Wahab
Author-Name: Abubaker Sayed Mohamed Omer
Author-X-Name-First: Abubaker Sayed Mohamed
Author-X-Name-Last: Omer
Author-Name: Kaan Yetilmezsoy
Author-X-Name-First: Kaan
Author-X-Name-Last: Yetilmezsoy
Author-Name: Majid Bahramian
Author-X-Name-First: Majid
Author-X-Name-Last: Bahramian
Title: Modelling the clogging of gas turbine filter houses in heavy-duty power generation systems
Abstract:
A prognostic approach based on a MISO (multiple inputs and single output) fuzzy logic model was introduced to estimate the pressure difference across a gas turbine (GT) filter house in a heavy-duty power generation system. For modelling and simulation of clogging of the GT filter house, nine real-time process variables (ambient temperature, humidity, ambient pressure, GT produced load, inlet guide vane position, airflow rate, wind speed, wind direction and PM10 dust concentration) were fuzzified using a graphical user interface within the framework of an artificial intelligence-based methodology. The results revealed that the proposed fuzzy logic model produced very small deviations and showed a superior predictive performance than the conventional multiple regression methodology, with a very high determination coefficient of 0.974. A complicated dynamic process, such as clogging phenomenonin heavy-duty GT system, was successfully modelled due to high capability of the fuzzy logic-based prognostic approach in capturing the nonlinear interactions.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 119-143
Issue: 2
Volume: 26
Year: 2020
Month: 3
X-DOI: 10.1080/13873954.2020.1713821
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1713821
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:2:p:119-143
Template-Type: ReDIF-Article 1.0
Author-Name: A. Errachdi
Author-X-Name-First: A.
Author-X-Name-Last: Errachdi
Author-Name: S. Slama
Author-X-Name-First: S.
Author-X-Name-Last: Slama
Author-Name: M. Benrejeb
Author-X-Name-First: M.
Author-X-Name-Last: Benrejeb
Title: On the combination of kernel principal component analysis and neural networks for process indirect control
Abstract:
A new adaptive kernel principal component analysis (KPCA) for non-linear discrete system control is proposed. The proposed approach can be treated as a new proposition for data pre-processing techniques. Indeed, the input vector of neural network controller is pre-processed by the KPCA method. Then, the obtained reduced neural network controller is applied in the indirect adaptive control. The influence of the input data pre-processing on the accuracy of neural network controller results is discussed by using numerical examples of the cases of time-varying parameters of single-input single-output non-linear discrete system and multi-input multi-output system. It is concluded that, using the KPCA method, a significant reduction in the control error and the identification error is obtained. The lowest mean squared error and mean absolute error are shown that the KPCA neural network with the sigmoid kernel function is the best.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 144-168
Issue: 2
Volume: 26
Year: 2020
Month: 3
X-DOI: 10.1080/13873954.2019.1710715
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1710715
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:2:p:144-168
Template-Type: ReDIF-Article 1.0
Author-Name: M. Bicher
Author-X-Name-First: M.
Author-X-Name-Last: Bicher
Author-Name: S. Winkler
Author-X-Name-First: S.
Author-X-Name-Last: Winkler
Author-Name: A. Körner
Author-X-Name-First: A.
Author-X-Name-Last: Körner
Title: Modelling a Viennese ballroom: agent-based simulation to investigate complex behaviour
Abstract:
Dancing Viennese Waltz in one of the great historic ballrooms is an important and indispensable part of Austrian culture. This dance, while being tradition, is quite difficult to perform, especially if the dance-floor is crowded. There, it is additionally challenging to avoid collisions with other dancers, as they pace through the ballroom at a high velocity. Dependent on the dancer’s skill level, spinning speed can be adjusted to succeed. This paper presents an agent-based waltz model which makes it possible to investigate the influence of heterogeneously skilled dancers on the movement smoothness of the dancing crowd. Herein, each agent represents one dancing couple in reality and it moves on the dance-floor by a rotatory motion with periodically switching rotation axes. Interaction between agents occurs via inelastic collisions. By performing a couple of case studies, we analyse and quantify the widespread rumour that the presence of only a few unskilled dancers disturbs the flow of the dancing crowd.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 169-192
Issue: 2
Volume: 26
Year: 2020
Month: 3
X-DOI: 10.1080/13873954.2020.1727930
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1727930
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:2:p:169-192
Template-Type: ReDIF-Article 1.0
Author-Name: Mahdi Sohrabi-Haghighat
Author-X-Name-First: Mahdi
Author-X-Name-Last: Sohrabi-Haghighat
Author-Name: Atefeh Deris
Author-X-Name-First: Atefeh
Author-X-Name-Last: Deris
Title: Growth rate, growth curve and growth prediction of tumour in the competitive model
Abstract:
The growth of cancer is still the focus of many research works in the scientific community. So far, various models have been introduced to analyse the behaviour of cancers, including the mathematical growth models such as Logistic, Gompertz and Bertalany. Despite the advances in the analysis of the cancer behaviour, the lack of definitive treatment of cancer disease indicates the need for new perspectives which are supported by more biological background. Recently, a model has been proposed, in which, the tumour growth is interpreted as the outcome of the competition of healthy and cancer cells over the available oxygen, nutrients and space. We have modified this model in order to provide the necessary preparations for wider use of the model in growth rate, growth curve and growth prediction of tumours. Meanwhile, the model is performed on some experimental data to show its capabilities.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 193-203
Issue: 2
Volume: 26
Year: 2020
Month: 3
X-DOI: 10.1080/13873954.2020.1738498
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1738498
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:2:p:193-203
Template-Type: ReDIF-Article 1.0
Author-Name: Dirk Zimmer
Author-X-Name-First: Dirk
Author-X-Name-Last: Zimmer
Title: Robust object-oriented formulation of directed thermofluid stream networks
Abstract:
Object-oriented formulation of thermal fluid streams often yields large non-linear equation systems whose numerical solution is difficult to achieve. This paper revisits the fundamental equations for thermal fluid streams and introduces a new term: the steady mass flow pressure $$\hat p$$pˆ. Using this term, the equations can be brought into a form where all non-linear computations are explicit. This enables a robust and object-oriented formulation of even complex architectures. The modelling of aircraft environmental control systems is presented as one possible application example.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 204-233
Issue: 3
Volume: 26
Year: 2020
Month: 6
X-DOI: 10.1080/13873954.2020.1757726
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1757726
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:3:p:204-233
Template-Type: ReDIF-Article 1.0
Author-Name: Shidi Miao
Author-X-Name-First: Shidi
Author-X-Name-Last: Miao
Author-Name: Di Liu
Author-X-Name-First: Di
Author-X-Name-Last: Liu
Author-Name: Junfeng Ma
Author-X-Name-First: Junfeng
Author-X-Name-Last: Ma
Author-Name: Feng Tian
Author-X-Name-First: Feng
Author-X-Name-Last: Tian
Title: System dynamics modelling of mixed recycling mode based on contract: a case study of online and offline recycling of E-waste in China
Abstract:
As the pace of global sustainable economic development accelerates, increasing attention has been brought to the reutilization of waste electronic resources (E-waste). As the leading manufacturer and consumer of electronic products, China has now become the largest producer of E-waste around the world. Considering the current state of recycling mode in China, Huawei Technologies Co. Ltd. (Huawei) took the lead in implementing a blended operation model of manufacturer-led recycling model (offline recycling, OffR) and retailer-led recycling model (online recycling, OnR). In order for the improvement of recycling efficiency for Huawei and other telecommunication companies, this paper constructs a closed-loop network model of mixed recycling (MR) between manufacturers and retailers based on contract, where manufacturers and retailers jointly recycle E-waste for the provision of E-waste to manufacturers for remanufacturing. In this paper, the MR model is compared against the OffR model and OnR model to evaluate the recycling allocation mechanism run by both manufacturer and retailer and then a contract-based, closed-loop network model of mixed recycling between manufacturers and retailers is developed on the basis of obtaining the optimal MR model. By means of simulation analysis, the optimal recycling allocation ratio between manufacturer and retailer is determined. The results obtained from this study are expected to help manufacturers and retailers with effective negotiation and cooperation, so as to improve the efficiency of E-waste recycling while promoting sustainable development and reducing the economic losses caused by price competition to the minimum. This research contributes to not only the waste management studies but also the recycling of E-waste in China and other countries.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 234-252
Issue: 3
Volume: 26
Year: 2020
Month: 6
X-DOI: 10.1080/13873954.2020.1762096
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1762096
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:3:p:234-252
Template-Type: ReDIF-Article 1.0
Author-Name: Yandong Wang
Author-X-Name-First: Yandong
Author-X-Name-Last: Wang
Author-Name: Ziming Kou
Author-X-Name-First: Ziming
Author-X-Name-Last: Kou
Author-Name: Guohua Cao
Author-X-Name-First: Guohua
Author-X-Name-Last: Cao
Title: Dynamic modelling of a multi-cable driven parallel platform with guiding devices
Abstract:
In this paper, a mathematical model is presented to numerically simulate the dynamical responses in a multi-cable suspension platform taking into account the slack cables and guiding devices. The state change of the cable (slack versus tensioned) is considered and is described mathematically by a complementary condition equation, and the interactions between the guiding wheels and the shaft wall are described by the Heaviside step function. The Lagrange’s equation with constraints is used to derive the dynamic equations of the system, and a non-smooth generalized-α algorithm for non-smooth phenomena of multibody dynamics is applied to numerically solve the equations. The simulation results have shown the dynamic responses of the platform and the cable tension characters when different cables are excited by different longitudinal excitations. Moreover, the results have illustrated how the cable tension differences may affect the pressure on the shaft wall applied by the guiding devices.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 253-267
Issue: 3
Volume: 26
Year: 2020
Month: 6
X-DOI: 10.1080/13873954.2020.1759653
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1759653
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:3:p:253-267
Template-Type: ReDIF-Article 1.0
Author-Name: Zafer Mahmoud
Author-X-Name-First: Zafer
Author-X-Name-Last: Mahmoud
Author-Name: Mohammad Reza Arvan
Author-X-Name-First: Mohammad Reza
Author-X-Name-Last: Arvan
Author-Name: Vahab Nekoukar
Author-X-Name-First: Vahab
Author-X-Name-Last: Nekoukar
Author-Name: Mohammad Rezaei
Author-X-Name-First: Mohammad
Author-X-Name-Last: Rezaei
Title: Trajectory-tracking of 6-RSS Stewart-Gough manipulator by feedback-linearization control using a novel inverse dynamic model based on the force distribution algorithm
Abstract:
6-RSS Stewart-Gough parallel manipulator contains six crank-rod limbs connecting the base and moving platforms to each other, forming a 6DOF manipulator. In this paper, we introduce a novel decoupled inverse dynamic model for this manipulator based on the Force Distribution Algorithm. The performance of the proposed model was evaluated in tracking a complex trajectory (of multiple segments with simultaneous translational and rotational motions) using feedback-linearization control in the joint space and compared with that of the Lagrangian inverse dynamic model. Results showed that this model leads to a better performance in feedback-linearization control, especially when the reference trajectory is quantized, and with less calculation burden in comparison with the Lagrangian model. The control system employing both models showed robustness against payload uncertainty on the moving platform (150% of the moving platform’s mass). The performance assessment and the robustness approval were performed in simulation using a Simscape model specifically built for this purpose in the Simulink environment.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 268-299
Issue: 3
Volume: 26
Year: 2020
Month: 6
X-DOI: 10.1080/13873954.2020.1754861
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1754861
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:3:p:268-299
Template-Type: ReDIF-Article 1.0
Author-Name: M. Abbes
Author-X-Name-First: M.
Author-X-Name-Last: Abbes
Author-Name: A. Farhat
Author-X-Name-First: A.
Author-X-Name-Last: Farhat
Author-Name: A. Mami
Author-X-Name-First: A.
Author-X-Name-Last: Mami
Title: Pseudo bond graph tunnel greenhouse model with accurate longwave/shortwave radiations model
Abstract:
This research work is focused on the construction of an accurate longwave/shortwave radiation model on a tunnel greenhouse pseudo-bond graph model, widely used in Tunisia. This model includes sun position, useful incoming solar radiation model, sky longwave radiation model, inside longwave and shortwave radiation model. The key idea is to use bond graphs allowing a lumped modelling approach which is suitable for control applications. Furthermore, an evaluation of some longwave radiative model components was made, noting that these components are particularly sensitive regarding to the thermal behaviour of the model.Experimental tunnel greenhouse data are used as validation elements for the present model with globally good results. A comparative study was also performed between the present model and a previous bond graph model containing a simplistic radiative model. Practical simulation results show a clear improvement compared with the previous model.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 90-114
Issue: 1
Volume: 25
Year: 2019
Month: 1
X-DOI: 10.1080/13873954.2018.1555172
File-URL: http://hdl.handle.net/10.1080/13873954.2018.1555172
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:1:p:90-114
Template-Type: ReDIF-Article 1.0
Author-Name: Mohamed Atia
Author-X-Name-First: Mohamed
Author-X-Name-Last: Atia
Title: Design and simulation of sensor fusion using symbolic engines
Abstract:
Sensor fusion is the art of estimating accurate information from noisy multi-sensor data. Due to the complexity of stochastic sensor errors, design and testing of sensor fusion algorithms have been always challenging. Existing design approaches are mainly mission specific with fixed system models that do not verify if the filter can estimate hidden errors. To address these challenges, this paper presents a flexible design and simulation environment for sensor fusion. The environment utilizes symbolic engine as a flexible representation of system models to enable flexible and accurate generation of linearized error models. Inverse kinematic is used to generate pseudo-error-free inertial data to test the ability of the filte to estimate sensor errors. The developed environment is demonstrated on an Attitude and Heading Reference System using Extended Kalman Filter. The demonstration includes both simulation and experimental tests. The designed filter supports both loosely and tightly coupled filtering approaches.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 40-62
Issue: 1
Volume: 25
Year: 2019
Month: 1
X-DOI: 10.1080/13873954.2019.1566266
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1566266
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:1:p:40-62
Template-Type: ReDIF-Article 1.0
Author-Name: Fateme Pourhasanzade
Author-X-Name-First: Fateme
Author-X-Name-Last: Pourhasanzade
Author-Name: S. H. Sabzpoushan
Author-X-Name-First: S. H.
Author-X-Name-Last: Sabzpoushan
Title: A cellular automata model of chemotherapy effects on tumour growth: targeting cancer and immune cells
Abstract:
The effects of therapy on avascular cancer development based on a stochastic cellular automata model are considered. Making the model more compatible with the biology of cancer, the following features are implemented: intrinsic resistance of cancerous cells along with drug-induced resistance, drug-sensitive cells, immune system. Results are reported for no treatment, discontinued treatment after only one cycle of chemotherapy, and periodic drug administration therapy modes. Growth fraction, necrotic fraction, and tumour volume are used as output parameters beside a 2-D graphical growth presentation. Periodic drug administration is more effective to inhibit the growth of tumours. The model has been validated by the verification of the simulation results using in vivo literature data. Considering immune cells makes the model more compatible with the biological realities. Beside targeting cancer cells, the model can also simulate the activation of the immune system to fight against cancer.Abbreviations CA: cellular automata; DSC: drug sensitive cell; DRC: drug resistant cell; GF: growth fraction; NF: necrotic fraction; ODE: ordinary differential equation; PDE: partial differential equation; SCAM: The proposed stochastic cellular automata model
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 63-89
Issue: 1
Volume: 25
Year: 2019
Month: 1
X-DOI: 10.1080/13873954.2019.1571515
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1571515
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:1:p:63-89
Template-Type: ReDIF-Article 1.0
Author-Name: Inge Troch
Author-X-Name-First: Inge
Author-X-Name-Last: Troch
Title: Adieu and welcome
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 301-303
Issue: 4
Volume: 26
Year: 2020
Month: 7
X-DOI: 10.1080/13873954.2020.1788809
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1788809
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:4:p:301-303
Template-Type: ReDIF-Article 1.0
Author-Name: Wolfgang Kemmetmüller
Author-X-Name-First: Wolfgang
Author-X-Name-Last: Kemmetmüller
Title: Editor’s note
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 304-305
Issue: 4
Volume: 26
Year: 2020
Month: 7
X-DOI: 10.1080/13873954.2020.1788808
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1788808
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:4:p:304-305
Template-Type: ReDIF-Article 1.0
Author-Name: Yanhong Liu
Author-X-Name-First: Yanhong
Author-X-Name-Last: Liu
Author-Name: Hui Lv
Author-X-Name-First: Hui
Author-X-Name-Last: Lv
Author-Name: Bin Wang
Author-X-Name-First: Bin
Author-X-Name-Last: Wang
Author-Name: Deyun Yang
Author-X-Name-First: Deyun
Author-X-Name-Last: Yang
Author-Name: Qiang Zhang
Author-X-Name-First: Qiang
Author-X-Name-Last: Zhang
Title: Modelling and analysis of haemoglobin catalytic reaction kinetic system
Abstract:
In order to study whether haemoglobin (Hb) can replace peroxidase and has good catalytic properties. The key to exploring the characteristics of Hb peroxidase is to establish a suitable kinetic model, which is studied in this paper. First, according to the Hb catalytic reaction, a nonlinear system is established and improved. It is proved that the established system is in line with the practical significance. The stability of the original system is judged by analysing the stability of the simplified system. Then, considering the effect of time delay on Hb catalytic reaction, a nonlinear time-delay catalytic reaction system is obtained. For convenient application, the system is linearized using Taylor’s formula, and the dynamic characteristics of Hopf bifurcation are analysed. The response diagrams of three system are plotted by setting perturbation parameters, and their variations are observed to analyse the differences among them. The results show that the nonlinear time-delay system can better describe the characteristics of the catalytic reaction.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 306-321
Issue: 4
Volume: 26
Year: 2020
Month: 7
X-DOI: 10.1080/13873954.2020.1771379
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1771379
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:4:p:306-321
Template-Type: ReDIF-Article 1.0
Author-Name: F. Cigarini
Author-X-Name-First: F.
Author-X-Name-Last: Cigarini
Author-Name: E. Csencsics
Author-X-Name-First: E.
Author-X-Name-Last: Csencsics
Author-Name: J. Schlarp
Author-X-Name-First: J.
Author-X-Name-Last: Schlarp
Author-Name: S. Ito
Author-X-Name-First: S.
Author-X-Name-Last: Ito
Author-Name: G. Schitter
Author-X-Name-First: G.
Author-X-Name-Last: Schitter
Title: Multiphysics finite element model for the computation of the electro-mechanical dynamics of a hybrid reluctance actuator
Abstract:
In hybrid reluctance actuators, the achievable closed-loop system bandwidth is affected by the eddy currents and hysteresis in the ferromagnetic components and the mechanical resonance modes. Such effects must be accurately predicted to achieve high performance via feedback control. Therefore, a multiphysics electro-mechanical finite element model is proposed in this paper to compute the dynamics of a 2-DoF hybrid reluctance actuator. An electromagnetic simulation is adopted to compute the electromagnetic dynamics and the actuation torque, which is employed as input for a structural dynamic simulation computing the electro-mechanical frequency response function. For model validation, the simulated and measured frequency response plots are compared for two actuators with solid and laminated outer yoke, respectively. In both cases, the model accurately predicts the measurement results, with a maximum relative phase error of 1.7% between the first resonance frequency and 1 kHz and a relative error of 1.5% for the second resonance frequency..
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 322-343
Issue: 4
Volume: 26
Year: 2020
Month: 7
X-DOI: 10.1080/13873954.2020.1766509
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1766509
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:4:p:322-343
Template-Type: ReDIF-Article 1.0
Author-Name: Sehrish Malik
Author-X-Name-First: Sehrish
Author-X-Name-Last: Malik
Author-Name: M. Bilal Ashraf
Author-X-Name-First: M. Bilal
Author-X-Name-Last: Ashraf
Author-Name: Adnan Jahangir
Author-X-Name-First: Adnan
Author-X-Name-Last: Jahangir
Title: Cattaneo–Christov heat flux model for three-dimensional flow of a viscoelastic fluid on an exponentially stretching surface
Abstract:
In this article, we explore the three-dimensional boundary-layer flow over an exponentially stretching surface in two parallel ways. Constitutive equations of a second-grade fluid are used. Instead of classical Fourier’s law, Cattaneo–Christov heat flux model is employed for the formulation of the energy equation. This model can predict the effects of thermal relaxation time on the boundary layer. The resulting partial differential equations are reduced into ordinary differential equations by similarity transformations. Homotopy Analysis Method (HAM) is employed to solve the non-linear problem. Physical impact of emerging parameters on the momentum and thermal boundary-layer thickness are studied.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 344-356
Issue: 4
Volume: 26
Year: 2020
Month: 7
X-DOI: 10.1080/13873954.2020.1777566
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1777566
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:4:p:344-356
Template-Type: ReDIF-Article 1.0
Author-Name: Jun Zhou
Author-X-Name-First: Jun
Author-X-Name-Last: Zhou
Author-Name: Dongbing Tong
Author-X-Name-First: Dongbing
Author-X-Name-Last: Tong
Author-Name: Qiaoyu Chen
Author-X-Name-First: Qiaoyu
Author-X-Name-Last: Chen
Author-Name: Wuneng Zhou
Author-X-Name-First: Wuneng
Author-X-Name-Last: Zhou
Title: Master-slave synchronization of neural networks with time-varying delays via the event-triggered control
Abstract:
This paper investigates the problem of master-slave synchronization of neural networks with time-varying delays via the event-triggered control (ETC). First, the proposed ETC can effectively reduce the total amount of data transmitted to the controller in the synchronization process and avoid communication channel congestion. Second, a master-slave synchronization of neural networks with time-varying delays is constructed, where delays within neural networks and the ETC are simultaneous existence. The controller is updated by the ETC. By the Lyapunov stability theory, some sufficient criteria are obtained to ensure master-slave synchronization of neural networks. Finally, a numerical example and a tunnel diode circuit example are used to verify the validity of results obtained.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 357-373
Issue: 4
Volume: 26
Year: 2020
Month: 7
X-DOI: 10.1080/13873954.2020.1777567
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1777567
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:4:p:357-373
Template-Type: ReDIF-Article 1.0
Author-Name: Puspita Mahata
Author-X-Name-First: Puspita
Author-X-Name-Last: Mahata
Author-Name: Gour Chandra Mahata
Author-X-Name-First: Gour Chandra
Author-X-Name-Last: Mahata
Title: Production and payment policies for an imperfect manufacturing system with discount cash flows analysis in fuzzy random environments
Abstract:
This paper considers an imperfect manufacturing system with credit policies in fuzzy random environments. The supplier simultaneously offers the retailer either a permissible delay in payments or a cash discount and retailer in turn provides its customer a permissible delay period. We used an alternate approach – discount cash flow analysis to establish an inventory problem. It is assumed that the elapsed time until the machine shifts from ‘in-control’ state to ‘out-of-control’ state is characterized as a fuzzy random variable. As a function of this parameter, the profit function is also a random fuzzy variable. Based on the credibility measure of fuzzy event, the model with fuzzy random elapsed time can be transformed into a crisp model . We establish several theoretical results to obtain the solution that provides the largest present value of all future cash flows. Finally, numerical example is given to illustrate the results and obtain some managerial insights.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 374-408
Issue: 4
Volume: 26
Year: 2020
Month: 7
X-DOI: 10.1080/13873954.2020.1771380
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1771380
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:4:p:374-408
Template-Type: ReDIF-Article 1.0
Author-Name: Luis A. Mora
Author-X-Name-First: Luis A.
Author-X-Name-Last: Mora
Author-Name: Le Gorrec Yann
Author-X-Name-First: Le Gorrec
Author-X-Name-Last: Yann
Author-Name: Hector Ramirez
Author-X-Name-First: Hector
Author-X-Name-Last: Ramirez
Author-Name: Juan Yuz
Author-X-Name-First: Juan
Author-X-Name-Last: Yuz
Title: Fluid-Structure Port-Hamiltonian Model for Incompressible Flows in Tubes with Time Varying Geometries
Abstract:
A simple and scalable finite-dimensional model based on the port-Hamiltonian framework is proposed to describe the fluid–structure interaction in tubes with time-varying geometries. For this purpose, the moving tube wall is described by a set of mass-spring-damper systems while the fluid is considered as a one-dimensional incompressible flow described by the average momentum dynamics in a set of incompressible flow sections. To couple these flow sections small compressible volumes are defined to describe the pressure between two adjacent fluid sections. The fluid-structure coupling is done through a power-preserving interconnection between velocities and forces. The resultant model includes external inputs for the fluid and inputs for external forces over the mechanical part that can be used for control or interconnection purposes. Numerical examples show the accordance of this simplified model with finite-element models reported in the literature.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 409-433
Issue: 5
Volume: 26
Year: 2020
Month: 09
X-DOI: 10.1080/13873954.2020.1786841
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1786841
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:5:p:409-433
Template-Type: ReDIF-Article 1.0
Author-Name: Hairui Zhang
Author-X-Name-First: Hairui
Author-X-Name-Last: Zhang
Author-Name: Yongxin Yuan
Author-X-Name-First: Yongxin
Author-X-Name-Last: Yuan
Title: Model updating for undamped gyroscopic systems with connectivity constraints
Abstract:
An important and difficult aspect for the finite element model updating problem is to make the updated model have physical meaning, that is, the connectivity of the original model should be preserved in the updated model. In many practical applications, the system matrices generated by discretization of a distributed parameter system with the finite element techniques are often very large and sparse and are of some special structures, such as symmetric and band structure (diagonal, tridiagonal, pentadiagonal, seven-diagonal, etc.). In this paper, the model updating problem for undamped gyroscopic systems with connectivity constraints is considered. The method proposed not only preserves the connectivity of the original model, but also can update the analytical matrices with different bandwidths, which can meet the needs of different structural dynamic model updating problems. Numerical results illustrate the efficiency of the proposed method.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 434-452
Issue: 5
Volume: 26
Year: 2020
Month: 09
X-DOI: 10.1080/13873954.2020.1787459
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1787459
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:5:p:434-452
Template-Type: ReDIF-Article 1.0
Author-Name: Ali Bagheri
Author-X-Name-First: Ali
Author-X-Name-Last: Bagheri
Author-Name: Nadia Esfandiari
Author-X-Name-First: Nadia
Author-X-Name-Last: Esfandiari
Author-Name: Bizhan Honarvar
Author-X-Name-First: Bizhan
Author-X-Name-Last: Honarvar
Author-Name: Amin Azdarpour
Author-X-Name-First: Amin
Author-X-Name-Last: Azdarpour
Title: First principles versus artificial neural network modelling of a solar desalination system with experimental validation
Abstract:
The present study mainly focuses on enhancing the performance of solar still unit using solar energy through cylindrical parabolic collector and solar panels. A 300 W solar panel is used to heat saline water by thermal elements outside the solar still unit. Solar panels are cooled during the hot hours of the day; thus, reducing their temperature may lead to an increase in solar panel efficiency followed by an increase in the efficiency of the solar still unit. The maximum amount of freshwater used in the experiment was 2.132 kg/day. The experiments were modelled using ANNs. Based on neural network simulation results, there is a significant correlation between experimental data and neural network modelling. This paper compares experimental data with data obtained from mathematical modelling and ANNs. As a conclusion, the artificial neural network prediction has been more accurate than the simplified first principles model presented.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 453-480
Issue: 5
Volume: 26
Year: 2020
Month: 09
X-DOI: 10.1080/13873954.2020.1788609
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1788609
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:5:p:453-480
Template-Type: ReDIF-Article 1.0
Author-Name: Yao Li
Author-X-Name-First: Yao
Author-X-Name-Last: Li
Title: Dynamic system optimal performances of shared autonomous and human vehicle system for heterogeneous travellers
Abstract:
Autonomous vehicles (AV) can solve vehicle relocation problems faced by traditional one-way vehicle-sharing systems. This paper explores the deterministic time-dependent system optimum of mixed shared AVs (SAV) and human vehicles (SHV) system to provide the benchmark for the situation of mixed vehicle flows. In such a system, the system planner determines vehicle-traveller assignment and optimal vehicle routing in transportation networks to serve predetermined travel demand of heterogeneous travellers. Due to large number of vehicles involved, travel time is considered endogenous with congestion. Using link transmission model (LTM) as a traffic flow model, the deterministic time-dependent system optimum is formulated as linear programming (LP) model to minimize the comprehensive cost including travellers’ travel time cost, waiting time cost and empty vehicle repositioning time cost. Numerical examples are conducted to show system performances and model effectiveness.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 481-499
Issue: 5
Volume: 26
Year: 2020
Month: 09
X-DOI: 10.1080/13873954.2020.1792509
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1792509
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:5:p:481-499
Template-Type: ReDIF-Article 1.0
Author-Name: L. Cveticanin
Author-X-Name-First: L.
Author-X-Name-Last: Cveticanin
Author-Name: M. Zukovic
Author-X-Name-First: M.
Author-X-Name-Last: Zukovic
Author-Name: Z. Rakaric
Author-X-Name-First: Z.
Author-X-Name-Last: Rakaric
Author-Name: D. Cveticanin
Author-X-Name-First: D.
Author-X-Name-Last: Cveticanin
Title: Modelling and analysis of the nonlinear string-mass structure of the vibration absorber
Abstract:
In this paper a nonlinear string-mass structure of the vibration absorber is analyzed. This structure is convenient to be installed in vibration damping systems of high buildings for their protection in the case of earthquake. The considered string-mass structure contains a translator movable mass connected with two strings. Due to nonlinear geometric properties of the system the motion of the mass is described with a strong nonlinear second order differential equation. In the paper the approximate procedure for solving of the nonlinear equation of motion is developed. Based on the solution the influence of the string preloading force, slider mass and friction force on the vibration property of the string-mass system is investigated. It is concluded that variation of the preloading string force may be applied as a control parameter for vibration absorption and as the regulator of vibration decay time.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 500-519
Issue: 5
Volume: 26
Year: 2020
Month: 09
X-DOI: 10.1080/13873954.2020.1792510
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1792510
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:5:p:500-519
Template-Type: ReDIF-Article 1.0
Author-Name: Xiao-Qiong Huang
Author-X-Name-First: Xiao-Qiong
Author-X-Name-Last: Huang
Author-Name: Yun-Xiang Han
Author-X-Name-First: Yun-Xiang
Author-X-Name-Last: Han
Title: System model building and dynamic online control of traffic flow
Abstract:
The Underground transportation system plays a vital role in public transportation and exhibits complicated dynamics. The model predictive control approach for underground train dispatching is proposed in this paper. The system modelling technique spatially aggregates trains to generate the traffic flow model in a network of interconnected control units. The state-space model for the underground train traffic of a metro line is investigated. Simulation results are reported to demonstrate the effectiveness of the optimization control model.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 521-533
Issue: 6
Volume: 26
Year: 2020
Month: 11
X-DOI: 10.1080/13873954.2020.1810076
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1810076
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:6:p:521-533
Template-Type: ReDIF-Article 1.0
Author-Name: Wenbin Gu
Author-X-Name-First: Wenbin
Author-X-Name-Last: Gu
Author-Name: Zhuo Li
Author-X-Name-First: Zhuo
Author-X-Name-Last: Li
Author-Name: Zeyu Chen
Author-X-Name-First: Zeyu
Author-X-Name-Last: Chen
Author-Name: Yuxin Li
Author-X-Name-First: Yuxin
Author-X-Name-Last: Li
Title: An energy-consumption model for establishing an integrated energy-consumption process in a machining system
Abstract:
Manufacturing industry accounts for a significant part of world’s energy consumption and environmental pollutions. Machining process is a major process of manufacturing industries, plays an important role in energy saving and emission reduction. This paper established an energy-consumption model for machining processes considering the full states of machining processes. Firstly, machining processes are decomposed into activities and activity transitions according to the different characteristics of energy demand. Secondly, based on the decomposition of activities and activity transitions, the energy-consumption models of activities and activity transitions are established, respectively. Thirdly, combining with the established energy-consumption models of activities and activity transitions, this paper proposes an energy-consumption model for the entire machining processes that systematically reflects different machining states. Finally, the simulation results show that the proposed model can accurately calculate the energy consumption of machining processes and provide guidance for machine tool energy saving.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 534-561
Issue: 6
Volume: 26
Year: 2020
Month: 11
X-DOI: 10.1080/13873954.2020.1833045
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1833045
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:6:p:534-561
Template-Type: ReDIF-Article 1.0
Author-Name: S. A Matveev
Author-X-Name-First: S. A
Author-X-Name-Last: Matveev
Author-Name: A. A Sorokin
Author-X-Name-First: A. A
Author-X-Name-Last: Sorokin
Author-Name: A. P Smirnov
Author-X-Name-First: A. P
Author-X-Name-Last: Smirnov
Author-Name: E.E. Tyrtyshnikov
Author-X-Name-First: E.E.
Author-X-Name-Last: Tyrtyshnikov
Title: Oscillating stationary distributions of nanoclusters in an open system
Abstract:
Steady-state oscillations of nanoparticle populations in the system of colliding monomers and seed-clusters are observed for the range of the seed-cluster source with diffusion and ballistic collision kernels. The dynamics of nanoparticles in this system is driven by monomer-cluster and cluster-cluster irreversible aggregation and described in terms of the number of primary monomers per nanoparticle based on solving the population balance equations as described by the classical system of Smoluchowski equations. The oscillations of particles’ concentrations arise with growing power of the source of seed-clusters and can remain visible for several orders of magnitute of particle sizes $$k$$k. For the case of constant kinetic coefficients the novel semi-analytial solution of the utilized aggregation model is found and results of numerical simulations with use of up to $${2^{20}}$$220 non-linear kinetic equations agree excellently with proposed theory.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 562-575
Issue: 6
Volume: 26
Year: 2020
Month: 11
X-DOI: 10.1080/13873954.2020.1793786
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1793786
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Handle: RePEc:taf:nmcmxx:v:26:y:2020:i:6:p:562-575
Template-Type: ReDIF-Article 1.0
Author-Name: T. W. Stegink
Author-X-Name-First: T. W.
Author-X-Name-Last: Stegink
Author-Name: C. De Persis
Author-X-Name-First: C.
Author-X-Name-Last: De Persis
Author-Name: A. J. Van Der Schaft
Author-X-Name-First: A. J.
Author-X-Name-Last: Van Der Schaft
Title: An energy-based analysis of reduced-order models of (networked) synchronous machines
Abstract:
Stability of power networks is an increasingly important topic because of the high penetration of renewable distributed generation units. This requires the development of advanced techniques for the analysis and controller design of power networks. Although there are widely accepted reduced-order models to describe the power network dynamics, they are commonly presented without details about the reduction procedure. The present article aims to provide a modular model derivation of multi-machine power networks. Starting from first-principle fundamental physics, we present detailed dynamical models of synchronous machines and clearly state the underlying assumptions which lead to some of the standard reduced-order multi-machine models. In addition, the energy functions for these models are derived, which allows to represent the multi-machine systems as port-Hamiltonian systems. Moreover, the systems are proven to be shifted passive, which permits for a power-preserving interconnection with other passive components.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 1-39
Issue: 1
Volume: 25
Year: 2019
Month: 01
X-DOI: 10.1080/13873954.2019.1566265
File-URL: http://hdl.handle.net/10.1080/13873954.2019.1566265
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Handle: RePEc:taf:nmcmxx:v:25:y:2019:i:1:p:1-39
Template-Type: ReDIF-Article 1.0
Author-Name: The Editors
Title: Correction
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 405-410
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2021.1932572
File-URL: http://hdl.handle.net/10.1080/13873954.2021.1932572
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:405-410
Template-Type: ReDIF-Article 1.0
Author-Name: Miao Chen
Author-X-Name-First: Miao
Author-X-Name-Last: Chen
Author-Name: Qing Zhang
Author-X-Name-First: Qing
Author-X-Name-Last: Zhang
Author-Name: Yunfei Ge
Author-X-Name-First: Yunfei
Author-X-Name-Last: Ge
Author-Name: Xianrong Qin
Author-X-Name-First: Xianrong
Author-X-Name-Last: Qin
Author-Name: Yuantao Sun
Author-X-Name-First: Yuantao
Author-X-Name-Last: Sun
Title: Dynamic analysis of an over-constrained parallel mechanism with the principle of virtual work
Abstract:
This research presents the mathematical modelling of kinematic and complete dynamic analysis of a novel over-constrained parallel mechanism, which consists of two universal-prismatic-revolute joint limbs and one revolute-revolute-universal joint limb. The kinematic model is constructed based on the closed-loop vector method and the velocity Jacobian matrix is deduced, velocity-mapping relationships between all moving components and moving platform are also performed. Afterwards, inertia and applied forces are analysed, the complete dynamic equations with the classical Stribeck friction model of the proposed structure is established based on the principle of virtual work. A theoretical numerical example is given to solve kinematics and dynamics solutions, and theoretical forces from developed dynamic formulation are verified by the physic model simulation in Simscape and the rigid-flexible coupling model simulation in Adams. A good agreement between the theoretical results and multi-body software simulation is found.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 347-372
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2021.1920618
File-URL: http://hdl.handle.net/10.1080/13873954.2021.1920618
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:347-372
Template-Type: ReDIF-Article 1.0
Author-Name: S.M. Dsouza
Author-X-Name-First: S.M.
Author-X-Name-Last: Dsouza
Author-Name: T. Khajah
Author-X-Name-First: T.
Author-X-Name-Last: Khajah
Author-Name: X Antoine
Author-X-Name-First: X
Author-X-Name-Last: Antoine
Author-Name: S.P.A. Bordas
Author-X-Name-First: S.P.A.
Author-X-Name-Last: Bordas
Author-Name: S. Natarajan
Author-X-Name-First: S.
Author-X-Name-Last: Natarajan
Title: Non Uniform Rational B-Splines and Lagrange approximations for time-harmonic acoustic scattering: accuracy and absorbing boundary conditions
Abstract:
The paper aims to evaluate the performance of the Lagrange-based finite element method and the non-uniform rational B-splines isogeometric analysis of time-harmonic acoustic exterior scattering problems using high-order local absorbing boundary conditions, in particular based on the Karp’s and Wilcox’s far-field expansions. The analysis of accuracy and convergence of both methods is achieved by observing the effect of the order of the approximating polynomial, the number of degrees of freedom, the wave number, and the absorbing boundary conditions tuning parameters. It is concluded that, regardless of the polynomial order, IGA provides a higher accuracy per degree of freedom compared to the traditional Lagrange-based finite element method.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 263-294
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2021.1902355
File-URL: http://hdl.handle.net/10.1080/13873954.2021.1902355
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:263-294
Template-Type: ReDIF-Article 1.0
Author-Name: Yasin Ucakan
Author-X-Name-First: Yasin
Author-X-Name-Last: Ucakan
Author-Name: Seda Gulen
Author-X-Name-First: Seda
Author-X-Name-Last: Gulen
Author-Name: Kevser Koklu
Author-X-Name-First: Kevser
Author-X-Name-Last: Koklu
Title: Analysing of Tuberculosis in Turkey through SIR, SEIR and BSEIR Mathematical Models
Abstract:
Since mathematical models play a key role in investigating the dynamics of infectious diseases, many mathematical models for these diseases are developed. In this paper, it is aimed to determine the dynamics of Tuberculosis (TB) in Turkey, how much it will affect the future and the impact of vaccine therapy on the disease. For this purpose, three mathematical models (SIR, SEIR and BSEIR) in the literature are considered for the case of Turkey. The model parameters are obtained with TB reported data from 2005 to 2015 by using the least square method. The obtained results revealed that the basic reproduction ratio for all three models is less than 1. Moreover, the stability analysis of the models and sensitivity analysis of the model parameters are presented and discussed. Finally, the accuracy of results for all three models is compared and the effect of the vaccination rate is discussed.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 179-202
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2021.1881560
File-URL: http://hdl.handle.net/10.1080/13873954.2021.1881560
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:179-202
Template-Type: ReDIF-Article 1.0
Author-Name: Huixia Huo
Author-X-Name-First: Huixia
Author-X-Name-Last: Huo
Author-Name: Houbao Xu
Author-X-Name-First: Houbao
Author-X-Name-Last: Xu
Author-Name: Zhuoqian Chen
Author-X-Name-First: Zhuoqian
Author-X-Name-Last: Chen
Title: Modelling and dynamic behaviour analysis of the software rejuvenation system with periodic impulse
Abstract:
Software rejuvenation is a policy to counter the phenomenon of software ageing. However, how to implement software rejuvenation is still an important issue. In this paper, periodic impulse control is proposed as an effective tool to perform software rejuvenation and improve the availability of software system. First, we formulate the software rejuvenation system with periodic impulse by a group of coupled differential equations with impulsive action. Then the well-posedness of the system is demonstrated by using operator semigroup theory. At the end of the paper, numerical examples are shown to illustrate the dynamic behaviour of the system and the relationship between the system instantaneous availability and the impulsive indexes, including impulse interval and impulse strength, which yields that the system availability can be improved by adjusting the impulsive indexes.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 522-542
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2021.1986074
File-URL: http://hdl.handle.net/10.1080/13873954.2021.1986074
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:522-542
Template-Type: ReDIF-Article 1.0
Author-Name: Teron Nguyen
Author-X-Name-First: Teron
Author-X-Name-Last: Nguyen
Author-Name: Patrick Swolana
Author-X-Name-First: Patrick
Author-X-Name-Last: Swolana
Author-Name: Bernhard Lechner
Author-X-Name-First: Bernhard
Author-X-Name-Last: Lechner
Author-Name: Wong Y.D.
Author-X-Name-First: Wong
Author-X-Name-Last: Y.D.
Title: An experimental comparison of mathematical heavy-duty city bus models to evaluate passenger ride comfort induced by road roughness
Abstract:
Mathematical models have been used widely to investigate the vehicle-passenger-infrastructure dynamical interaction; however, the responses of various heavy-duty city bus models to estimate ride comfort induced by road roughness are still unknown. In this study, the comparison of dynamical response of buses used in city transport is investigated based on multi-degrees-of-freedom (DOF) bus models developed in MATLAB/Simulink and correlated against passenger ride comfort criteria. The results showed that 9-DOF full bus model is the best option to estimate passenger ride comfort within an error of 2%, as compared to 5-DOF half and 3-DOF quarter bus models with 7% and 20% errors using one wheel-track, and 24% and 36% errors using two wheel-tracks, respectively. The error was calculated as the difference between simulated results from three bus models and the measured data. These mathematical bus models can be customized for estimating passenger ride comfort and surface roughness of dedicated bus/bus-rapid-transit lanes.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 203-221
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2021.1887276
File-URL: http://hdl.handle.net/10.1080/13873954.2021.1887276
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:203-221
Template-Type: ReDIF-Article 1.0
Author-Name: Liang Zeng
Author-X-Name-First: Liang
Author-X-Name-Last: Zeng
Title: Forecasting the primary energy consumption using a time delay grey model with fractional order accumulation
Abstract:
Energy consumption prediction is a hot issue, which is of great significance to regional energy security. In the existing prediction research with small samples, the time delay characteristic of an energy consumption system in itself is often ignored. To reflect the time delay characteristic of an energy consumption system and accurately grasp its development trend, a novel nonlinear time delay grey model with fractional order accumulation is presented. The new model is utilized to forecast and analyze Guangdong’s primary energy consumption, in which the time delay parameter is ascertained by the grey correlation analysis method, and the other parameters are determined via particle swarm optimization. The results show the simulation accuracy of the new model is higher than those of the other 3 grey models, and the predicted results in the next three years can provide decision-making and theoretical reference for the relevant departments of Guangdong province.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 31-49
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2020.1859547
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1859547
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:31-49
Template-Type: ReDIF-Article 1.0
Author-Name: Philip L. Neureuther
Author-X-Name-First: Philip L.
Author-X-Name-Last: Neureuther
Author-Name: Kevin Schmidt
Author-X-Name-First: Kevin
Author-X-Name-Last: Schmidt
Author-Name: Thomas Bertram
Author-X-Name-First: Thomas
Author-X-Name-Last: Bertram
Author-Name: Oliver Sawodny
Author-X-Name-First: Oliver
Author-X-Name-Last: Sawodny
Title: Control oriented modelling and modal analysis of the deformable mirror M4 of the extremely large telescope
Abstract:
In this article, we derive a mechanical distributed parameter model for the annular sector plate segments of the Extremely Large Telescope’s deformable mirror M4. Additionally, we modally analyse the derived model via analytical and numerical approaches. The deformable mirror M4 is used to reject wavefront disturbances and enhance the optical imaging quality. We present a control oriented annular sector Kirchhoff–Love plate model featuring an elastic boundary condition and its modal analysis for one of the six identical M4 segments. Subsequently, we show that the well-known method of separation of variables is incompatible with the modal analysis of the presented distributed parameter model in cylindrical coordinates. Moreover, we successfully modally analyse the model using a finite difference approximation and a realistic construction of an M4 segment via a finite element approximation to compare the results. The modal analyses provide consistent results and therefore, both models underlying the analyses are consistent.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 295-321
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2020.1850480
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1850480
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:295-321
Template-Type: ReDIF-Article 1.0
Author-Name: Georg Jäger
Author-X-Name-First: Georg
Author-X-Name-Last: Jäger
Title: Using Neural Networks for a Universal Framework for Agent-based Models
Abstract:
Traditional agent-based modelling is mostly rule-based. For many systems, this approach is extremely successful, since the rules are well understood. However, for a large class of systems it is difficult to find rules that adequately describe the behaviour of the agents. A simple example would be two agents playing chess: Here, it is impossible to find simple rules. To solve this problem, we introduce a framework for agent-based modelling that incorporates machine learning. In a process closely related to reinforcement learning, the agents learn rules. As a trade-off, a utility function needs to be defined, which is much simpler in most cases. We test this framework to replicate the results of the prominent Sugarscape model as a proof of principle. Furthermore, we investigate a more complicated version of the Sugarscape model, that exceeds the scope of the original framework. By expanding the framework we also find satisfying results there.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 162-178
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2021.1889609
File-URL: http://hdl.handle.net/10.1080/13873954.2021.1889609
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:162-178
Template-Type: ReDIF-Article 1.0
Author-Name: S. Ali A. Moosavian
Author-X-Name-First: S. Ali A.
Author-X-Name-Last: Moosavian
Author-Name: Mahdi Nabipour
Author-X-Name-First: Mahdi
Author-X-Name-Last: Nabipour
Author-Name: Farshid Absalan
Author-X-Name-First: Farshid
Author-X-Name-Last: Absalan
Author-Name: Vahid Akbari
Author-X-Name-First: Vahid
Author-X-Name-Last: Akbari
Title: RoboWalk: augmented human-robot mathematical modelling for design optimization
Abstract:
Utilizing exoskeleton devices to help elderly or empower workers is a growing field of research in robotics. The structure of an exoskeleton can vary depending on user’s physical dimensions, joints or muscles targeted for assistance, and maximum achievable actuator torque. In this research, a Human-Model-In-the-Loop (HMIL) constrained optimization technique is proposed to design the RoboWalk lower-limb exoskeleton. RoboWalk is an under-actuated non-anthropomorphic assistive robot, that besides applying the desired assistive force, exerts an undesirable disturbing force leading to the user’s fall. The HMIL method uses the augmented human-robot 2D model to take RoboWalk and human body’s joint torques into account during optimization. The superiority of HMIL method is proven by comparing the results with other strategies in the literature. Obtained results reveal elimination of the disturbing forces, 2 N.m. reduction in average human knee-joint torque, and significant decrease in the actuator required torque.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 373-404
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2021.1879874
File-URL: http://hdl.handle.net/10.1080/13873954.2021.1879874
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:373-404
Template-Type: ReDIF-Article 1.0
Author-Name: R. Altmann
Author-X-Name-First: R.
Author-X-Name-Last: Altmann
Author-Name: V. Mehrmann
Author-X-Name-First: V.
Author-X-Name-Last: Mehrmann
Author-Name: B. Unger
Author-X-Name-First: B.
Author-X-Name-Last: Unger
Title: Port-Hamiltonian formulations of poroelastic network models
Abstract:
We investigate an energy-based formulation of the two-field poroelasticity model and the related multiple-network model as they appear in geosciences or medical applications. We propose a port-Hamiltonian formulation of the system equations, which is beneficial for preserving important system properties after discretization or model-order reduction. For this, we include the commonly omitted second-order term and consider the corresponding first-order formulation. The port-Hamiltonian formulation of the quasi-static case is then obtained by (formally) setting the second-order term zero. Further, we interpret the poroelastic equations as an interconnection of a network of submodels with internal energies, adding a control-theoretic understanding of the poroelastic equations.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 429-452
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2021.1975137
File-URL: http://hdl.handle.net/10.1080/13873954.2021.1975137
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:429-452
Template-Type: ReDIF-Article 1.0
Author-Name: J. Fernandez de Canete
Author-X-Name-First: J.
Author-X-Name-Last: Fernandez de Canete
Author-Name: D. Cuesta
Author-X-Name-First: D.
Author-X-Name-Last: Cuesta
Author-Name: A. Luque
Author-X-Name-First: A.
Author-X-Name-Last: Luque
Author-Name: J. Barbancho
Author-X-Name-First: J.
Author-X-Name-Last: Barbancho
Title: Physical modelling and computer simulation of the cardiorespiratory system based on the use of a combined electrical analogy
Abstract:
Modelling the human cardiorespiratory system using computer simulation tools can serve to help physicians to comprehend the causes and development of cardiorespiratory diseases. The objective of this paper is to develop an integrated model of the cardiovascular and respiratory systems, along with their intrinsic control mechanisms, by combining analogous hydraulic-electric and diffusion-electric circuits, respectively. This modelling task is performed in object-oriented language in SIMSCAPE using the physical interconnected components to define the underlying dynamic equations. Simulation steady state results under rest and under variable physical exercise conditions, as well as under limiting conditions show a high qualitative agreement with clinical observations reported in literature. This object-oriented modelling approach, based on the combined use of electrical analogies, proves to be avaluable tool as a test bench for different strategies aimed to qualitative prediction of the effects of cardiorespiratory interactions during exercise, thus avoiding the formulation of complex mathematical models.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 453-488
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2021.1977335
File-URL: http://hdl.handle.net/10.1080/13873954.2021.1977335
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:453-488
Template-Type: ReDIF-Article 1.0
Author-Name: Andreas Rauh
Author-X-Name-First: Andreas
Author-X-Name-Last: Rauh
Author-Name: Julia Kersten
Author-X-Name-First: Julia
Author-X-Name-Last: Kersten
Author-Name: Wiebke Frenkel
Author-X-Name-First: Wiebke
Author-X-Name-Last: Frenkel
Author-Name: Niklas Kruse
Author-X-Name-First: Niklas
Author-X-Name-Last: Kruse
Author-Name: Tom Schmidt
Author-X-Name-First: Tom
Author-X-Name-Last: Schmidt
Title: Physically motivated structuring and optimization of neural networks for multi-physics modelling of solid oxide fuel cells
Abstract:
Neural network models for complex dynamical systems typically do not explicitly account for structural engineering insight and mutual interrelations of various subprocesses that are related to the multi-physics nature of such systems. For that reason, they are commonly interpreted as a kind of data-driven, black box modelling option that is in opposition to a physically inspired equation-based system representation for which suitable parameters are subsequently identified in a grey box sense. To bridge the gap between data-driven and equation-based modelling paradigms, this paper proposes a novel approach for a physics-inspired structuring of neural networks. The derivation of this kind of structuring, an optimal choice of network inputs and numbers of neurons in a hidden layer as well as the achievable modelling accuracy are demonstrated for the thermal and electrochemical behaviour of high-temperature fuel cells. Finally, different network structures are compared against experimental data.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 586-614
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2021.1990966
File-URL: http://hdl.handle.net/10.1080/13873954.2021.1990966
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:586-614
Template-Type: ReDIF-Article 1.0
Author-Name: B. Talebjedi
Author-X-Name-First: B.
Author-X-Name-Last: Talebjedi
Author-Name: T. Laukkanen
Author-X-Name-First: T.
Author-X-Name-Last: Laukkanen
Author-Name: H. Holmberg
Author-X-Name-First: H.
Author-X-Name-Last: Holmberg
Author-Name: E. Vakkilainen
Author-X-Name-First: E.
Author-X-Name-Last: Vakkilainen
Author-Name: S. Syri
Author-X-Name-First: S.
Author-X-Name-Last: Syri
Title: Energy simulation and variable analysis of refining process in thermo-mechanical pulp mill using machine learning approach
Abstract:
Data from two thermo-mechanical pulp mills are collected to simulate the refining process using deep learning. A multilayer perceptron neural network is utilized for pattern recognition of the refining variables. Results show the impressive capability of artificial intelligence methods in refining energy simulation so that the correlation coefficient of 98% is accessible. A comprehensive parametric study has been made to investigate the effect of refining disturbance variables, plate gap and dilution water on refining energy simulation. The generated model reveals the non-linear hidden pattern between refining variables, which can be used for optimal refining control strategy. Considering the disturbance variables’ effect in refining energy simulation, model accuracy could increase by 15%. Removing the plate gape from predictive variables reduces the simulation determination coefficient by up to 25% in both mills, while the mentioned value for removing dilution water is 9–17% in mill 1 and about 35% in mill 2.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 562-585
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2021.1990967
File-URL: http://hdl.handle.net/10.1080/13873954.2021.1990967
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:562-585
Template-Type: ReDIF-Article 1.0
Author-Name: A. Suruliandi
Author-X-Name-First: A.
Author-X-Name-Last: Suruliandi
Author-Name: G. Mariammal
Author-X-Name-First: G.
Author-X-Name-Last: Mariammal
Author-Name: S.P. Raja
Author-X-Name-First: S.P.
Author-X-Name-Last: Raja
Title: Crop prediction based on soil and environmental characteristics using feature selection techniques
Abstract:
Earlier, crop cultivation was undertaken on the basis of farmers’ hands-on expertise. However, climate change has begun to affect crop yields badly. Consequently, farmers are unable to choose the right crop/s based on soil and environmental factors, and the process of manually predicting the choice of the right crop/s of land has, more often than not, resulted in failure. Accurate crop prediction results in increased crop production. This is where machine learning playing a crucial role in the area of crop prediction. Crop prediction depends on the soil, geographic and climatic attributes. Selecting appropriate attributes for the right crop/s is an intrinsic part of the prediction undertaken by feature selection techniques. In this work, a comparative study of various wrapper feature selection methods are carried out for crop prediction using classification techniques that suggest the suitable crop/s for land. The experimental results show the Recursive Feature Elimination technique with the Adaptive Bagging classifier outperforms the others.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 117-140
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2021.1882505
File-URL: http://hdl.handle.net/10.1080/13873954.2021.1882505
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:117-140
Template-Type: ReDIF-Article 1.0
Author-Name: Sherif M. Sharroush
Author-X-Name-First: Sherif M.
Author-X-Name-Last: Sharroush
Author-Name: Yasser S. Abdalla
Author-X-Name-First: Yasser S.
Author-X-Name-Last: Abdalla
Title: Parameter extraction and modelling of the MOS transistor by an equivalent resistance
Abstract:
During the analysis of multi-transistor circuits, the need arises to evaluate the time delay or the power consumption of the circuit. Due to the complexity of the transistor model, several complicated equations arise from which a compact-form solution cannot be obtained and a suitable physical insight cannot be drawn. With this regard, two contributions are presented in this paper. The first one is a fully analytical parameter extraction approach to be applied on the MOS transistors. The second one is a quantitative method for simplifying the analysis of MOS circuits by modelling the MOS transistor by a suitable equivalent resistance adopting the time-delay or the power-consumption equivalence criteria. The parameter-extraction method is verified by using the extracted parameters in the derived expressions according to the second contribution. Compared to other representations, the agreement of the proposed model with the simulation results is very good.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 50-86
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2020.1857790
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1857790
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:50-86
Template-Type: ReDIF-Article 1.0
Author-Name: Frank Müller
Author-X-Name-First: Frank
Author-X-Name-Last: Müller
Title: Approximating the solution of the discharging process in a domestic hot water storage tank
Abstract:
In this article a new approximation procedure for the temperature during the discharging process in a domestic hot water storage tank is developed. The main idea of this procedure is the mathematical description of the dynamic behaviour of a boundary layer that appears inside the storage tank. This leads to an approximate solution of a simple structure but a high accuracy throughout the whole discharging process for the temperature distribution inside the storage tank. For validation the approximate solution is compared with the exact solution that is constructed with help of generalized Fourier coefficients and a numerical solution that is obtained by a semi-discretization method. Adapting the method leads also to an approximation procedure for charging processes.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 141-161
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2021.1887277
File-URL: http://hdl.handle.net/10.1080/13873954.2021.1887277
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:141-161
Template-Type: ReDIF-Article 1.0
Author-Name: Sukhwinder Kaur
Author-X-Name-First: Sukhwinder
Author-X-Name-Last: Kaur
Author-Name: Prashant Kumar
Author-X-Name-First: Prashant
Author-X-Name-Last: Kumar
Author-Name: Rajni
Author-X-Name-First:
Author-X-Name-Last: Rajni
Title: Mathematical Modelling of Non-Linear Transient Long Waves by using Finite Element Method in an Irregular Shaped Harbour
Abstract:
Extreme waves significantly affect the coastal structures, activities, and population. Therefore, investigation of extreme wave impact on coastal regions is essential. In this study, a mathematical model is presented to analyse the impact of transient long waves on coastal structures. The mathematical model is constructed based on the Boussinesq equation (BE) with variable water depth including dispersion properties. The numerical solution of BE is constructed by using FEM. The present numerical model is validated through the existing study of Lepelletier (1981) and convergence analysis is also conducted to determine the convergence rate. The present FEM model is implemented on realistic Paradip port, Odisha, India to determine the wave amplitude at various record stations. In addition, the impact of incident waves with angular variation is analysed in the Paradip port. The causes and countermeasures have been proposed based on the simulation results to improve the resonance in the port.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 411-428
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2021.1973510
File-URL: http://hdl.handle.net/10.1080/13873954.2021.1973510
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:411-428
Template-Type: ReDIF-Article 1.0
Author-Name: Marko Milojković
Author-X-Name-First: Marko
Author-X-Name-Last: Milojković
Author-Name: Miroslav Milovanović
Author-X-Name-First: Miroslav
Author-X-Name-Last: Milovanović
Author-Name: Saša S. Nikolić
Author-X-Name-First: Saša S.
Author-X-Name-Last: Nikolić
Author-Name: Miodrag Spasić
Author-X-Name-First: Miodrag
Author-X-Name-Last: Spasić
Author-Name: Andjela Antić
Author-X-Name-First: Andjela
Author-X-Name-Last: Antić
Title: Designing optimal models of nonlinear MIMO systems based on orthogonal polynomial neural networks
Abstract:
This paper presents a new method for modelling of dynamic systems by using specially designed orthogonal polynomial neural networks. These networks utilize the feature that the basis made of orthogonal functions can be used for approximation of arbitrary function, while their property of orthogonality enables optimal performances in the sense of both convergence time and approximation error. In this regard, generalized quasi-orthogonal polynomials, specifically tailored for the application in the modelling of complex dynamic systems with time-varying behaviour, are considered. Adaptivity of the designed model is achieved by using variable factors inside the orthogonal basis. The designed orthogonal neural network is applied in modelling of laboratory twin-rotor aero-dynamic system as a representative of nonlinear multiple input-multiple output systems. Detailed comparative analysis is performed for a different number of polynomials in expansion with the purpose of finding the optimal model in the sense of trade-off between model accuracy and complexity.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 246-262
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2021.1909069
File-URL: http://hdl.handle.net/10.1080/13873954.2021.1909069
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:246-262
Template-Type: ReDIF-Article 1.0
Author-Name: Olusegun J. Ilegbusi
Author-X-Name-First: Olusegun J.
Author-X-Name-Last: Ilegbusi
Author-Name: Don Nadun S Kuruppumullage
Author-X-Name-First: Don Nadun S
Author-X-Name-Last: Kuruppumullage
Author-Name: Bari Hoffman
Author-X-Name-First: Bari
Author-X-Name-Last: Hoffman
Title: Dynamics of cough and particulate behaviour in the human airway
Abstract:
Computational Fluid Dynamics is used to model airflow and penetrant behaviour under cough reflex in human airway. The airway geometry segment from the oral cavity to the primary bronchi is reconstructed from CT scan images of a human subject in the standing posture. The inlet flow condition is derived from dynamic cough profiles obtained from two subjects. The mathematical model allows the laryngopharyngeal wall of the airway to remodel. A k-ω turbulence model is used to represent the transitional flow. A Lagrangian approach is used to track solid penetrants in the flow field as a function of penetrant size and density. High velocities are predicted at peak expiratory cough phase. The penetrant size significantly influences the particle residence time and drag force is largely responsible for changes in the penetrant momentum. The smaller penetrants act like tracers in the flow and can escape the airway faster than larger penetrants.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 222-245
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2021.1889608
File-URL: http://hdl.handle.net/10.1080/13873954.2021.1889608
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:222-245
Template-Type: ReDIF-Article 1.0
Author-Name: Kaede Iinuma
Author-X-Name-First: Kaede
Author-X-Name-Last: Iinuma
Author-Name: Kiminao Kogiso
Author-X-Name-First: Kiminao
Author-X-Name-Last: Kogiso
Title: Emotion-involved human decision-making model
Abstract:
This study proposes a computational human decision-making model that handles emotion-induced behaviour. The proposed model can determine a rational or irrational action according to a probability distribution obtained by mixing an optimal policy of a partially observable Markov decision process and an evolved probability distribution by novel dynamics of emotions. Emotion dynamics with consecutive negative observations cause emotion-induced irrational behaviours. We clarify the conditions, via two theorems, that the proposed model computes rational and irrational actions in terms of some model parameters. A numerical example based on Japanese court records is used to confirm that the proposed model imitates the human decision-making process. Moreover, we discuss the possibility of preventive measures for avoiding the murder case scenario. This study shows that if the traits of a decision maker can be modelled, the proposed model can support human interactions to avoid an emotion-driven murder case scenario.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 543-561
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2021.1986846
File-URL: http://hdl.handle.net/10.1080/13873954.2021.1986846
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:543-561
Template-Type: ReDIF-Article 1.0
Author-Name: Markus Lohmayer
Author-X-Name-First: Markus
Author-X-Name-Last: Lohmayer
Author-Name: Paul Kotyczka
Author-X-Name-First: Paul
Author-X-Name-Last: Kotyczka
Author-Name: Sigrid Leyendecker
Author-X-Name-First: Sigrid
Author-X-Name-Last: Leyendecker
Title: Exergetic port-Hamiltonian systems: modelling basics
Abstract:
Port-Hamiltonian systems theory provides a structured approach to modelling, optimization and control of multiphysical systems. Yet, its relationship to thermodynamics seems to be unclear. The Hamiltonian is traditionally thought of as energy, although its meaning is exergy. This insight yields benefits: 1. Links to the GENERIC structure are identified, making it relatively easy to borrow ideas from a popular nonequilibrium thermodynamics framework. 2. The port-Hamiltonian structure combined with a bond-graph syntax is expected to become a main ingredient in thermodynamic optimization methods akin to exergy analysis and beyond. The intuitive nature of exergy and diagrammatic language facilitates interdisciplinary communication that is necessary for implementing sustainable energy systems and processes. Port-Hamiltonian systems are cyclo-passive, meaning that a power-balance equation immediately follows from their definition. For exergetic port-Hamiltonian systems, cyclo-passivity is synonymous with degradation of energy and follows from the first and the second law of thermodynamics being encoded as structural properties.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 489-521
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2021.1979592
File-URL: http://hdl.handle.net/10.1080/13873954.2021.1979592
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:489-521
Template-Type: ReDIF-Article 1.0
Author-Name: Ricardo Campa
Author-X-Name-First: Ricardo
Author-X-Name-Last: Campa
Author-Name: Israel Soto
Author-X-Name-First: Israel
Author-X-Name-Last: Soto
Author-Name: Omar Martínez
Author-X-Name-First: Omar
Author-X-Name-Last: Martínez
Title: Modelling and control of a spherical pendulum via a non–minimal state representation
Abstract:
A spherical pendulum is a 2 degree-of-freedom mechanism consisting on a rod whose tip moves on the surface of a sphere. It is common to use two angular coordinates to describe such a system. This paper proposes the use of a non-minimal set of coordinates for modelling and controlling a fully-actuated torque-driven spherical pendulum. These coordinates is merely for the purpose of showing the application of unit quaternions as a useful tool for dealing with the orientation of rigid bodies. First, we recall the properties of unit quaternions, and explain how they can be employed for the definition of such non-minimal pendulum coordinates. Later, the control objective for orientation regulation is established and an inverse-dynamics controller, which uses joint displacement and velocity measurements but also some non-minimal states for the orientation error, is proposed. The stability analysis shows the fulfilment of the control objective and is validated through simulations.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 3-30
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2020.1853175
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1853175
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:3-30
Template-Type: ReDIF-Article 1.0
Author-Name: Mohammad Hadi Jalali
Author-X-Name-First: Mohammad Hadi
Author-X-Name-Last: Jalali
Author-Name: Geoff Rideout
Author-X-Name-First: Geoff
Author-X-Name-Last: Rideout
Title: Three-Dimensional Dynamic Modelling and Validation for Vibration of a Beam-Cable System
Abstract:
In order to understand and to predict cable effects on structures, three-dimensional numerical models for a stranded cable and a beam–cable system consisting of a cantilever beam and two connected cables are presented. The multibond graph formalism is used to model the coupled cable–beam system, with the cable and beam substructures using 3D rigid lumped segments. The stranded cables are modelled considering the bending stiffness, tension and sag due to self-weight. The generally applicable cable-structure modelling approach in this paper is applied to vibration-based non-destructive evaluation of electrical utility poles, where simulated modal testing of the pole-conductor system is required. Experimental parametrization of a stranded cable is carried out using specially designed apparatus to accurately measure the bending stiffness at different tensions, and to measure the axial stiffness and axial damping. A reduced-scale lab set-up and finite element models are developed for verification of the numerical models. Experimental free and forced vibration testing is performed on individual cantilever beam and stranded cable subsystems, and on the coupled cable–beam system to verify the numerical models in the frequency and time domains. It is concluded that the 3D bond graph models can be used to understand the interaction between cable and structure, allowing prediction of the in-plane and out-of-plane natural frequencies and time response of the connected pole. It is also concluded that by adding the cable to the pole structure, some modes emerge in the eigenvalue solution of the system which may be categorized as cable-dominated modes, pole-dominated or hybrid modes.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 87-116
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2020.1871372
File-URL: http://hdl.handle.net/10.1080/13873954.2020.1871372
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:87-116
Template-Type: ReDIF-Article 1.0
Author-Name: Simon Densborn
Author-X-Name-First: Simon
Author-X-Name-Last: Densborn
Author-Name: Oliver Sawodny
Author-X-Name-First: Oliver
Author-X-Name-Last: Sawodny
Title: Flexible multibody system modelling of an aerial rescue ladder using Lagrange’s equations
Abstract:
Due to limited weight and stiffness, large-scale robots are susceptible to structural oscillations during operation. In this publication, a model for the vertical dynamics of an aerial rescue ladder as an application example for large scale flexible robots is derived based on the Lagrange formalism. The model consists of five flexible segments, each using an arbitrary number of flexible modes. Kinematic loops occurring due to the type of interconnection between the telescopic elements are implicitly solved by the chosen assumed modes. Linearized system matrices are extracted from the model directly and very efficiently. In the resulting modelling process, the manipulator is solely described by its position and orientation kinematics and thus an adaption to different kinds of manipulators is straightforward. A validation against real world measurement data confirms the high accuracy of the derived model.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 322-346
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2021.1918175
File-URL: http://hdl.handle.net/10.1080/13873954.2021.1918175
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:322-346
Template-Type: ReDIF-Article 1.0
Author-Name: The Editors
Title: Editorial
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 1-2
Issue: 1
Volume: 27
Year: 2021
Month: 01
X-DOI: 10.1080/13873954.2021.1872922
File-URL: http://hdl.handle.net/10.1080/13873954.2021.1872922
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Handle: RePEc:taf:nmcmxx:v:27:y:2021:i:1:p:1-2
Template-Type: ReDIF-Article 1.0
# input file: NMCM_A_2080718_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949
Author-Name: Paul Treml
Author-X-Name-First: Paul
Author-X-Name-Last: Treml
Author-Name: Gudrun Mikota
Author-X-Name-First: Gudrun
Author-X-Name-Last: Mikota
Author-Name: Bernhard Manhartsgruber
Author-X-Name-First: Bernhard
Author-X-Name-Last: Manhartsgruber
Author-Name: Andreas Brandl
Author-X-Name-First: Andreas
Author-X-Name-Last: Brandl
Title: Modelling of a hydraulic system coupled with lumped masses
Abstract:
A coupled hydraulic-mechanical system with a lumped parametric mechanical part has been set up, measured and mathematically modelled in the frequency domain. The main focus of this article is the identification of unknown system parameters, which depends on the models of coupling and dissipation. The set-up under investigation can be excited hydraulically, by flow rate, or mechanically, by force. The responding pressures of the hydraulic subsystem and the accelerations of the mechanical subsystem are measured, from which transfer functions between excitation and system states can be calculated. The property of reciprocity is used for the processing of measurement data. With a suitable two-step strategy and non-linear optimization unknown system parameters can be identified from measurements. Additionally, the agreement of model and measurement and the physical meaningfulness of these parameters are examined. The proposed model succeeds in predicting measured transfer functions, whose data weren't used for the identification of model parameters.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 142-196
Issue: 1
Volume: 28
Year: 2022
Month: 12
X-DOI: 10.1080/13873954.2022.2080718
File-URL: http://hdl.handle.net/10.1080/13873954.2022.2080718
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Handle: RePEc:taf:nmcmxx:v:28:y:2022:i:1:p:142-196
Template-Type: ReDIF-Article 1.0
# input file: NMCM_A_2038637_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949
Author-Name: Jens Jäschke
Author-X-Name-First: Jens
Author-X-Name-Last: Jäschke
Author-Name: Matthias Ehrhardt
Author-X-Name-First: Matthias
Author-X-Name-Last: Ehrhardt
Author-Name: Michael Günther
Author-X-Name-First: Michael
Author-X-Name-Last: Günther
Author-Name: Birgit Jacob
Author-X-Name-First: Birgit
Author-X-Name-Last: Jacob
Title: A port-Hamiltonian formulation of coupled heat transfer
Abstract:
Heat transfer and cooling solutions play an important role in the design of gas turbine blades. However, the underlying mathematical coupling structures have not been thoroughly investigated. In this work, the port-Hamiltonian formalism is applied to the conjugate heat transfer problem in gas turbine blades. A mathematical model based on common engineering simplifications is constructed and further simplified to reduce complexity and focus on the coupling structures of interest. The model is then cast as a port-Hamiltonian system and examined for stability and well posedness.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 78-94
Issue: 1
Volume: 28
Year: 2022
Month: 12
X-DOI: 10.1080/13873954.2022.2038637
File-URL: http://hdl.handle.net/10.1080/13873954.2022.2038637
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Handle: RePEc:taf:nmcmxx:v:28:y:2022:i:1:p:78-94
Template-Type: ReDIF-Article 1.0
# input file: NMCM_A_2052111_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949
Author-Name: Thomas Makowicki
Author-X-Name-First: Thomas
Author-X-Name-Last: Makowicki
Author-Name: Matthias Bitzer
Author-X-Name-First: Matthias
Author-X-Name-Last: Bitzer
Author-Name: Knut Graichen
Author-X-Name-First: Knut
Author-X-Name-Last: Graichen
Title: Cycle-by-Cycle Combustion Optimisation: Calibration of Data-based Models and Improvements of Computational Efficiency
Abstract:
Modern combustion engines require an efficient cycle-by-cycle fuel injection control scheme to optimise the single combustion events during transient operation. The online optimisation of the respective control inputs typically needs accurate while sufficiently simple models of the combustion quantities. Based on a recently presented cycle-by-cycle optimisation scheme with a hybrid model, this paper focuses on two aspects to enhance the accuracy as well as computational efficiency for an online computation. Firstly, the proper calibration of Gaussian processes nested in a combined physics-/data-based model structure is addressed. Respective test bench measurements and a tailored two-step training procedure are presented. Secondly, the computational efficiency of the online cycle-by-cycle optimisation is increased by mapping computationally intensive calculations into the data-based models through offline preprocessing. In addition, a data-driven approximation of the complete optimisation scheme is proposed to further minimise the computational demand. Simulation studies are used to evaluate the performance of these approaches.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 110-141
Issue: 1
Volume: 28
Year: 2022
Month: 12
X-DOI: 10.1080/13873954.2022.2052111
File-URL: http://hdl.handle.net/10.1080/13873954.2022.2052111
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Handle: RePEc:taf:nmcmxx:v:28:y:2022:i:1:p:110-141
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# input file: NMCM_A_2143531_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949
Author-Name: Mihiran Galagedarage Don
Author-X-Name-First: Mihiran
Author-X-Name-Last: Galagedarage Don
Author-Name: Geoff Rideout
Author-X-Name-First: Geoff
Author-X-Name-Last: Rideout
Title: An experimentally-verified approach for enhancing fluid drag force simulation in vertical oilwell drill strings
Abstract:
The oilwell drilling fluid flows cause viscous and hydrodynamic forces on drill strings. This effect is ignored or treated as a constant in most drill string models. The present study introduces mathematical models for lateral vibration damping and axial drag forces that are employable in lumped segment drill string models. First, the variables to which drilling fluid-generated forces are most sensitive were identified and the Response Surface Method was applied to design the experiment matrix. The lateral vibration-damping experiments, which were validated using a scaled-down physical model, and the axial drag experiments were done using Fluid-Structure Interaction simulations. The results were statistically analysed to acquire the models and were implemented in a 3D lumped segment bond graph developed using the Newton-Euler formulation and body-fixed coordinates. The results indicate a considerable effect of the extended treatment of damping and axial drag on bending moment fluctuation, wellbore interactions, and weight on bit.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 197-228
Issue: 1
Volume: 28
Year: 2022
Month: 12
X-DOI: 10.1080/13873954.2022.2143531
File-URL: http://hdl.handle.net/10.1080/13873954.2022.2143531
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Handle: RePEc:taf:nmcmxx:v:28:y:2022:i:1:p:197-228
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# input file: NMCM_A_2033274_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949
Author-Name: Memduh Karalar
Author-X-Name-First: Memduh
Author-X-Name-Last: Karalar
Author-Name: Murat Cavuslu
Author-X-Name-First: Murat
Author-X-Name-Last: Cavuslu
Title: Determination of 3D near fault seismic behaviour of Oroville earth fill dam using burger material model and free field-quiet boundary conditions
Abstract:
In this study, the three-dimensional (3D) near-fault earthquake performance of the Oroville dam is examined considering a special material model and various seismic boundary conditions. The 3D finite-difference model of the Oroville EF dam is modeled using the finite difference method. Burger Creep (BC) material model is utilized for the foundation and dam body materials. Special interface elements are taken into account between the dam body and foundation. Fix, free field, and quiet seismic boundary conditions are considered for 3D nonlinear earthquake analyses. Total six various strong near-fault earthquakes are used in the 3D analyses. According to the non-linear earthquake analyses, principal stresses, horizontal and vertical displacements for three nodal points are assessed in detail and numerical results are compared for reflecting and non-reflecting seismic boundary conditions. It is clearly understood that seismic boundary conditions should not be utilized randomly for 3D modeling and analysis of EF dams.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 55-77
Issue: 1
Volume: 28
Year: 2022
Month: 12
X-DOI: 10.1080/13873954.2022.2033274
File-URL: http://hdl.handle.net/10.1080/13873954.2022.2033274
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Handle: RePEc:taf:nmcmxx:v:28:y:2022:i:1:p:55-77
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# input file: NMCM_A_2007138_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949
Author-Name: Luis Lüttgens
Author-X-Name-First: Luis
Author-X-Name-Last: Lüttgens
Author-Name: Benjamin Jurgelucks
Author-X-Name-First: Benjamin
Author-X-Name-Last: Jurgelucks
Author-Name: Heinrich Wernsing
Author-X-Name-First: Heinrich
Author-X-Name-Last: Wernsing
Author-Name: Sylvain Roy
Author-X-Name-First: Sylvain
Author-X-Name-Last: Roy
Author-Name: Christof Büskens
Author-X-Name-First: Christof
Author-X-Name-Last: Büskens
Author-Name: Kathrin Flaßkamp
Author-X-Name-First: Kathrin
Author-X-Name-Last: Flaßkamp
Title: Autonomous navigation of ships by combining optimal trajectory planning with informed graph search
Abstract:
Autonomous trajectory generation plays an essential role in the navigation of vehicles in space as well as in terrestrial scenarios, i.e. in the air, on solid ground, or water. For the latter, the navigation of ships in ports has specific challenges since ship dynamics are highly nonlinear with limited agility, while the manoeuvre space in ports is limited. Nevertheless, for providing support to humanly designed control strategies, autonomously generated trajectories have not only to be feasible, i.e. collision-free but shall also be optimal with respect to manoeuvre time and control effort. This article presents a novel approach to autonomous trajectory planning on the basis of precomputed and connectable trajectory segments, the so-called motion primitives, and an A*-search algorithm. Sequences of motion primitives provide an initial guess for a subsequent optimization by which optimal trajectories are found even in terrains with many obstacles. We illustrate the approach with different navigation scenarios.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 1-27
Issue: 1
Volume: 28
Year: 2022
Month: 12
X-DOI: 10.1080/13873954.2021.2007138
File-URL: http://hdl.handle.net/10.1080/13873954.2021.2007138
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Handle: RePEc:taf:nmcmxx:v:28:y:2022:i:1:p:1-27
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# input file: NMCM_A_2020296_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949
Author-Name: Cordula Reisch
Author-X-Name-First: Cordula
Author-X-Name-Last: Reisch
Title: Modelling health impacts of hepatitis – model selection and treatment plans
Abstract:
Hepatitis B and C are viruses causing liver infections and resulting in grave secondary diseases. While there are different treatments for chronic liver infections, the process of evolving chronic diseases is still not fully understood. This paper presents an economic-inspired model for the overall health of an infected organism. The health model is based on the results of a reaction diffusion model for describing the space-dependent dynamics of virus and T cells during a liver infection. The different treatments affect the parameters of the reaction diffusion model and influence therefore the well-being of the infected person during an infection. The health model is selected in a detailed process out of a class of possible models. The presented work provides a foundation for an optimal control problem for finding the best treatment strategy.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 28-54
Issue: 1
Volume: 28
Year: 2022
Month: 12
X-DOI: 10.1080/13873954.2021.2020296
File-URL: http://hdl.handle.net/10.1080/13873954.2021.2020296
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Handle: RePEc:taf:nmcmxx:v:28:y:2022:i:1:p:28-54
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# input file: NMCM_A_2039717_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949
Author-Name: Georg Jäger
Author-X-Name-First: Georg
Author-X-Name-Last: Jäger
Author-Name: Daniel Reisinger
Author-X-Name-First: Daniel
Author-X-Name-Last: Reisinger
Title: Can we replicate real human behaviour using artificial neural networks?
Abstract:
Agent-based modelling is a powerful tool when simulating human systems, yet when human behaviour cannot be described by simple rules or maximizing one’s own profit, we quickly reach the limits of this methodology. Machine learning has the potential to bridge this gap by providing a link between what people observe and how they act in order to reach their goal. In this paper we use a framework for agent-based modelling that utilizes human values like fairness, conformity and altruism. Using this framework we simulate a public goods game and compare to experimental results. We can report good agreement between simulation and experiment and furthermore find that the presented framework outperforms strict reinforcement learning. Both the framework and the utility function are generic enough that they can be used for arbitrary systems, which makes this method a promising candidate for a foundation of a universal agent-based model.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 95-109
Issue: 1
Volume: 28
Year: 2022
Month: 12
X-DOI: 10.1080/13873954.2022.2039717
File-URL: http://hdl.handle.net/10.1080/13873954.2022.2039717
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Handle: RePEc:taf:nmcmxx:v:28:y:2022:i:1:p:95-109
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# input file: NMCM_A_2209798_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231203T183118 git hash: be90730853
Author-Name: Tim Moser
Author-X-Name-First: Tim
Author-X-Name-Last: Moser
Author-Name: Boris Lohmann
Author-X-Name-First: Boris
Author-X-Name-Last: Lohmann
Title: A Rosenbrock framework for tangential interpolation of port-Hamiltonian descriptor systems
Abstract:
We present a new structure-preserving model order reduction (MOR) framework for large-scale port-Hamiltonian descriptor systems (pH-DAEs). Our method exploits the structural properties of the Rosenbrock system matrix for this system class and utilizes condensed forms which often arise in applications and reveal the solution behaviour of a system. Provided that the original system has such a form, our method produces reduced-order models (ROMs) of minimal dimension, which tangentially interpolate the original model’s transfer function and are guaranteed to be again in pH-DAE form. This allows the ROM to be safely coupled with other dynamical systems when modelling large system networks, which is useful, for instance, in electric circuit simulation.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 210-235
Issue: 1
Volume: 29
Year: 2023
Month: 12
X-DOI: 10.1080/13873954.2023.2209798
File-URL: http://hdl.handle.net/10.1080/13873954.2023.2209798
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Handle: RePEc:taf:nmcmxx:v:29:y:2023:i:1:p:210-235
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# input file: NMCM_A_2243685_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231203T183118 git hash: be90730853
Author-Name: Serkan Araci
Author-X-Name-First: Serkan
Author-X-Name-Last: Araci
Author-Name: Wolfgang Kemmetmüller
Author-X-Name-First: Wolfgang
Author-X-Name-Last: Kemmetmüller
Title: Updated Editorial Team and Thanks to Retiring Board Members
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 208-209
Issue: 1
Volume: 29
Year: 2023
Month: 12
X-DOI: 10.1080/13873954.2023.2243685
File-URL: http://hdl.handle.net/10.1080/13873954.2023.2243685
File-Format: text/html
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Handle: RePEc:taf:nmcmxx:v:29:y:2023:i:1:p:208-209
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# input file: NMCM_A_2178466_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231203T183118 git hash: be90730853
Author-Name: Julian Landauer
Author-X-Name-First: Julian
Author-X-Name-Last: Landauer
Author-Name: Andreas Kugi
Author-X-Name-First: Andreas
Author-X-Name-Last: Kugi
Author-Name: Andreas Steinböck
Author-X-Name-First: Andreas
Author-X-Name-Last: Steinböck
Title: Mathematical modelling of an electrostatic oiling machine for steel strips
Abstract:
This paper deals with the mathematical modelling of the electrostatic spraying process in an industrial electrostatic oiling machine (EOM) for steel strips. Measurements from an industrial EOM show that the thickness and inhomogeneity of the oil film on the strips frequently exceed specified tolerance limits whereby the reasons were previously unknown. A numerical model of the spraying process is developed in ANSYS Fluent, which serves as the basis for a root-cause analysis of the erroneous oil film thickness. In contrast to other works in this area, a droplet break-up model, which describes the break-up of the oil droplets due to the charge they carry, is included to get more accurate results. The model is validated based on measurement data from an industrial oiling machine. It is demonstrated that the model yields a better understanding of the spraying process and it is successfully used to improve the oiling process.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 69-94
Issue: 1
Volume: 29
Year: 2023
Month: 12
X-DOI: 10.1080/13873954.2023.2178466
File-URL: http://hdl.handle.net/10.1080/13873954.2023.2178466
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Handle: RePEc:taf:nmcmxx:v:29:y:2023:i:1:p:69-94
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# input file: NMCM_A_2173238_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231203T183118 git hash: be90730853
Author-Name: Johannes Rettberg
Author-X-Name-First: Johannes
Author-X-Name-Last: Rettberg
Author-Name: Dominik Wittwar
Author-X-Name-First: Dominik
Author-X-Name-Last: Wittwar
Author-Name: Patrick Buchfink
Author-X-Name-First: Patrick
Author-X-Name-Last: Buchfink
Author-Name: Alexander Brauchler
Author-X-Name-First: Alexander
Author-X-Name-Last: Brauchler
Author-Name: Pascal Ziegler
Author-X-Name-First: Pascal
Author-X-Name-Last: Ziegler
Author-Name: Jörg Fehr
Author-X-Name-First: Jörg
Author-X-Name-Last: Fehr
Author-Name: Bernard Haasdonk
Author-X-Name-First: Bernard
Author-X-Name-Last: Haasdonk
Title: Port-Hamiltonian fluid–structure interaction modelling and structure-preserving model order reduction of a classical guitar
Abstract:
A fluid–structure interaction model in a port-Hamiltonian representation is derived for a classical guitar. After discretization, we combine the laws of continuum mechanics for solids and fluids within a unified port-Hamiltonian (pH) modelling approach by adapting the equations through an appropriate coordinate transformation on the second-order level. The high-dimensionality of the resulting system is reduced by model order reduction. The article focuses on pH-systems in different state transformations, a variety of basis generation techniques as well as structure-preserving model order reduction approaches that are independent from the projection basis. As main contribution, a thorough comparison of these method combinations is conducted. In contrast to typical frequency-based simulations in acoustics, transient time simulations of the system are presented. The approach is embedded into a straightforward workflow of sophisticated commercial software modelling and flexible in-house software for multi-physics coupling and model order reduction.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 116-148
Issue: 1
Volume: 29
Year: 2023
Month: 12
X-DOI: 10.1080/13873954.2023.2173238
File-URL: http://hdl.handle.net/10.1080/13873954.2023.2173238
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Handle: RePEc:taf:nmcmxx:v:29:y:2023:i:1:p:116-148
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# input file: NMCM_A_2244175_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231203T183118 git hash: be90730853
Author-Name: Bhawna Malik
Author-X-Name-First: Bhawna
Author-X-Name-Last: Malik
Author-Name: Samit Bhattacharyya
Author-X-Name-First: Samit
Author-X-Name-Last: Bhattacharyya
Title: A stochastic model of antibiotic misuse, economy, and drug resistance: relating mutant extinction probability to socioeconomic and epidemiological factors
Abstract:
Controlling antibiotic drug resistance requires understanding extinction and emergence mechanisms of emerging bacteria. Selective pressure from prolonged antibiotic misuse may cause high-level antimicrobial resistance. Self-medication and other socioeconomic factors reduce antibiotic use, accelerating the emergence and extinction of resistant pathogens through stochastic fluctuation. This continuous antibiotic self-medication exposes individuals and communities to antibiotic resistance, especially in low- and lower-middle-income countries, according to current literature. We developed a stochastic drug-resistance model that integrates socio-economic growth and antibiotic use to study extinction and strain establishment in this paper. We analytically derived the extinction threshold using the multi-type branching process and obtained pathogen extinction conditions that match numerical experiments. The model's sensitivity analysis identifies extinction dynamics' key parameters. Our results show that higher income, awareness, and lower antibiotic use may increase the chance of extinction by reducing antibiotic misuse, along with strain transmission potential. These analyses may help public health policymakers combat drug resistance.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 236-264
Issue: 1
Volume: 29
Year: 2023
Month: 12
X-DOI: 10.1080/13873954.2023.2244175
File-URL: http://hdl.handle.net/10.1080/13873954.2023.2244175
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Handle: RePEc:taf:nmcmxx:v:29:y:2023:i:1:p:236-264
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# input file: NMCM_A_2177311_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231203T183118 git hash: be90730853
Author-Name: M. Meiringer
Author-X-Name-First: M.
Author-X-Name-Last: Meiringer
Author-Name: A. Kugi
Author-X-Name-First: A.
Author-X-Name-Last: Kugi
Author-Name: W. Kemmetmüller
Author-X-Name-First: W.
Author-X-Name-Last: Kemmetmüller
Title: Modelling and calibration of a five link elastic boom of a mobile concrete pump
Abstract:
Large-scale manipulators, such as the boom of a mobile concrete pump, typically rely on lightweight construction to maximize their operational range. As a result, significant elastic deformations occur during operation. Various automation and control applications require computationally fast and accurate mathematical models of the manipulator’s motion. In this work, a mathematical model for the boom of a mobile concrete pump with 5 individual joints is presented. This model takes into account the elastic bending in two directions and the torsion of the boom. To reach a high model accuracy, calibration is required. This is challenging due to the large dimension and the outdoor operation, which makes the accurate measurement of the boom position difficult. A camera-based measurement setup is proposed in this work that is tailored for the considered problem. It is shown by measurements that the model is able to achieve a high accuracy with rather small computational costs.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 41-68
Issue: 1
Volume: 29
Year: 2023
Month: 12
X-DOI: 10.1080/13873954.2023.2177311
File-URL: http://hdl.handle.net/10.1080/13873954.2023.2177311
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Handle: RePEc:taf:nmcmxx:v:29:y:2023:i:1:p:41-68
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# input file: NMCM_A_2158875_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231203T183118 git hash: be90730853
Author-Name: Athanasios Martsopoulos
Author-X-Name-First: Athanasios
Author-X-Name-Last: Martsopoulos
Author-Name: Thomas L. Hill
Author-X-Name-First: Thomas L.
Author-X-Name-Last: Hill
Author-Name: Rajendra Persad
Author-X-Name-First: Rajendra
Author-X-Name-Last: Persad
Author-Name: Stefanos Bolomytis
Author-X-Name-First: Stefanos
Author-X-Name-Last: Bolomytis
Author-Name: Antonia Tzemanaki
Author-X-Name-First: Antonia
Author-X-Name-Last: Tzemanaki
Title: Modelling and real-time dynamic simulation of flexible needles for prostate biopsy and brachytherapy
Abstract:
Percutaneous needle insertion constitutes a widely adopted technique for performing minimally invasive operations. Robot-assisted needle placement and virtual surgical training platforms have the potential to significantly improve the accuracy of these operations. For this, the development of mathematical models that provide a complete characterization of the underlying dynamics of medical needles is considered of paramount importance. In this paper, we develop two three-dimensional nonlinear rigid/flexible dynamic models of brachytherapy and local anaesthetic transperineal biopsy (LATP) needles. The proposed models relax the assumptions of previous investigations, quantify the vibrational behaviour and the rigid-body dynamics of medical needles and allow for real-time haptic and visual feedback information. Their accuracy and computational efficiency are assessed and validated using commercial software. The results show that, among the examined methods, the Rigid Finite Element Method provides the most accurate and numerically efficient solution for capturing the dynamics of flexible medical needles.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 1-40
Issue: 1
Volume: 29
Year: 2023
Month: 12
X-DOI: 10.1080/13873954.2022.2158875
File-URL: http://hdl.handle.net/10.1080/13873954.2022.2158875
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Handle: RePEc:taf:nmcmxx:v:29:y:2023:i:1:p:1-40
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# input file: NMCM_A_2284360_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231203T183118 git hash: be90730853
Author-Name: Taekyun Kim
Author-X-Name-First: Taekyun
Author-X-Name-Last: Kim
Author-Name: Dae San Kim
Author-X-Name-First: Dae San
Author-X-Name-Last: Kim
Author-Name: Jongkyum Kwon
Author-X-Name-First: Jongkyum
Author-X-Name-Last: Kwon
Author-Name: Hyunseok Lee
Author-X-Name-First: Hyunseok
Author-X-Name-Last: Lee
Title: Lerch-harmonic numbers related to Lerch transcendent
Abstract:
Harmonic numbers and generalized harmonic numbers have been studied in connection with combinatorial problems, many expressions involving special functions in analytic number theory and analysis of algorithms. We introduce Lerch-harmonic numbers which generalize the harmonic numbers and the generalized harmonic numbers. The aim of this note is to derive some identities expressing certain finite sums as the infinite sums involving the Lerch-harmonic numbers. Then, by taking limits of such identities we obtain the corresponding infinite sums of the finite sums as the infinite sums involving the Lerch transcendents.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 315-323
Issue: 1
Volume: 29
Year: 2023
Month: 12
X-DOI: 10.1080/13873954.2023.2284360
File-URL: http://hdl.handle.net/10.1080/13873954.2023.2284360
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Handle: RePEc:taf:nmcmxx:v:29:y:2023:i:1:p:315-323
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# input file: NMCM_A_2276440_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231203T183118 git hash: be90730853
Author-Name: Mubashir Qayyum
Author-X-Name-First: Mubashir
Author-X-Name-Last: Qayyum
Author-Name: Aneeza Tahir
Author-X-Name-First: Aneeza
Author-X-Name-Last: Tahir
Author-Name: Abdul Bariq
Author-X-Name-First: Abdul
Author-X-Name-Last: Bariq
Author-Name: Ali Akgül
Author-X-Name-First: Ali
Author-X-Name-Last: Akgül
Author-Name: Syed Tauseef Saeed
Author-X-Name-First: Syed Tauseef
Author-X-Name-Last: Saeed
Title: Modeling and analysis of thin film flow of Fuzzified Johnson Segalman nanofluid using fuzzy extension of He-Laplace scheme
Abstract:
The concept of fuzzy calculus in fluid modelling offers a feasible approach to address ambiguity and uncertainty in physical phenomena. This study aims to model and analyse thin film flow of Johnson Segalman nonofluid (JSNF) on a vertical belt in fuzzy environment for lifting and drainage settings. By incorporating Triangular fuzzy numbers (TFNs), a more accurate representation of the uncertain nature of JSNF flow is obtained which leads to a better understanding of fluid behaviour and its potential applications. The fluid problems are modelled with uncertainties and numerically solved through fuzzy extension of He-Laplace algorithm. The validity and convergence of the proposed methodology is checked by computing residual errors in each case. The obtained solutions provide fuzzy velocity profiles and volumetric flow rates in lift and drain cases. As the parameter $r - cut$r−cut approaches 1, the velocity profiles at the upper and lower bounds merge, indicating solution consistency.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 286-314
Issue: 1
Volume: 29
Year: 2023
Month: 12
X-DOI: 10.1080/13873954.2023.2276440
File-URL: http://hdl.handle.net/10.1080/13873954.2023.2276440
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Handle: RePEc:taf:nmcmxx:v:29:y:2023:i:1:p:286-314
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# input file: NMCM_A_2222170_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231203T183118 git hash: be90730853
Author-Name: Gang Yu
Author-X-Name-First: Gang
Author-X-Name-Last: Yu
Author-Name: Dong Li
Author-X-Name-First: Dong
Author-X-Name-Last: Li
Author-Name: Yuling Duan
Author-X-Name-First: Yuling
Author-X-Name-Last: Duan
Title: Numerical investigation for influence of powered effect on aerodynamic performance of BWB takeoff configuration
Abstract:
The influence of the powered effect on the aerodynamic performance of the blended-wing-body (BWB) takeoff configuration is analysed in this study by solving the three-dimensional Reynolds-averaged Navier–Stokes equation on a multiblock structured grid. The powered effect on the aerodynamic performance of the BWB300 configuration was investigated with through-flow nacelle (TFN) and powered nacelle (PN) using this method. The results showed that although the influence of the powered effect caused a slight change in the aerodynamic performance of the BWB takeoff configuration, it did not change the development trend of the aerodynamic performance of the BWB takeoff configuration. Therefore, the TFN model can be used to obtain the general development trend of the aerodynamic performance of the BWB takeoff configuration in the early stages of the BWB design. However, when more accurate aerodynamic values are required, the powered effect should be considered.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 149-168
Issue: 1
Volume: 29
Year: 2023
Month: 12
X-DOI: 10.1080/13873954.2023.2222170
File-URL: http://hdl.handle.net/10.1080/13873954.2023.2222170
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Handle: RePEc:taf:nmcmxx:v:29:y:2023:i:1:p:149-168
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# input file: NMCM_A_2282974_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231203T183118 git hash: be90730853
Author-Name: Minilik Ayalew
Author-X-Name-First: Minilik
Author-X-Name-Last: Ayalew
Author-Name: Mulualem Aychluh
Author-X-Name-First: Mulualem
Author-X-Name-Last: Aychluh
Author-Name: Daya Lal Suthar
Author-X-Name-First: Daya Lal
Author-X-Name-Last: Suthar
Author-Name: Sunil Dutt Purohit
Author-X-Name-First: Sunil Dutt
Author-X-Name-Last: Purohit
Title: Quadratic upwind differencing scheme in the finite volume method for solving the convection-diffusion equation
Abstract:
Due to the high importance of the convection-diffusion equation, we aim to develop a quadratic upwind differencing scheme in the finite volume approach for solving this equation. Our newly developed numerical approach is conditionally stable. The strategy employs a quadratic upwind differencing scheme in the finite volume technique for spatial approximation with third-order accuracy. The temporal integration is approximated using the explicit theta method of first-order accuracy. Some numerical examples are given to support our theoretical procedures. The findings are plotted using MATLAB R2016a mathematical software.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 265-285
Issue: 1
Volume: 29
Year: 2023
Month: 12
X-DOI: 10.1080/13873954.2023.2282974
File-URL: http://hdl.handle.net/10.1080/13873954.2023.2282974
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Handle: RePEc:taf:nmcmxx:v:29:y:2023:i:1:p:265-285
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# input file: NMCM_A_2236681_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231203T183118 git hash: be90730853
Author-Name: Anna Lo Grasso
Author-X-Name-First: Anna
Author-X-Name-Last: Lo Grasso
Author-Name: Ada Fort
Author-X-Name-First: Ada
Author-X-Name-Last: Fort
Author-Name: Fariba Fahmideh Mahdizadeh
Author-X-Name-First: Fariba Fahmideh
Author-X-Name-Last: Mahdizadeh
Author-Name: Agnese Magnani
Author-X-Name-First: Agnese
Author-X-Name-Last: Magnani
Author-Name: Chiara Mocenni
Author-X-Name-First: Chiara
Author-X-Name-Last: Mocenni
Title: Generalized logistic model of bacterial growth
Abstract:
This work proposes a new mathematical model describing the dynamics of growing bacterial cultures. The model, described by a first order non-linear differential equation, as a generalization of the logistic equation, was compared with the most studied mathematical models. All models were numerically implemented and fitted to the experimental data, collected from the incubation of a bacterial strain of Pseudomonas fluorescens, to obtain the growth parameters. The experimental data showed the lowest fit error for both the Baranyi–Roberts and new models, which turned out to be equivalent. Simulations of the fitting algorithm were also implemented and repeated for a large number of initial guesses of the parameters, chosen in order to test the fitting and convergence performances. The innovative feature that makes the new model easier to use than Baranyi–Roberts model is definitely its simple and manageable analytical form and its good performance in terms of convergence time.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 169-185
Issue: 1
Volume: 29
Year: 2023
Month: 12
X-DOI: 10.1080/13873954.2023.2236681
File-URL: http://hdl.handle.net/10.1080/13873954.2023.2236681
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Handle: RePEc:taf:nmcmxx:v:29:y:2023:i:1:p:169-185
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# input file: NMCM_A_2184835_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231203T183118 git hash: be90730853
Author-Name: Qinghe Yao
Author-X-Name-First: Qinghe
Author-X-Name-Last: Yao
Author-Name: Zhuolin Wang
Author-X-Name-First: Zhuolin
Author-X-Name-Last: Wang
Author-Name: Yi Zhang
Author-X-Name-First: Yi
Author-X-Name-Last: Zhang
Author-Name: Zijie Li
Author-X-Name-First: Zijie
Author-X-Name-Last: Li
Author-Name: Junyang Jiang
Author-X-Name-First: Junyang
Author-X-Name-Last: Jiang
Title: Towards real-time fluid dynamics simulation: a data-driven NN-MPS method and its implementation
Abstract:
In this work, we construct a data-driven model to address the computing performance problem of the moving particle semi-implicit method by combining the physics intuition of the method with a machine-learning algorithm. A fully connected artificial neural network is implemented to solve the pressure Poisson equation, which is reformulated as a regression problem. We design context-based feature vectors for particle-based on the Poisson equation. The neural network maintains the original particle method’s accuracy and stability, while drastically accelerates the pressure calculation. It is very suitable for GPU parallelization, edge computing scenarios and real-time simulations.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 95-115
Issue: 1
Volume: 29
Year: 2023
Month: 12
X-DOI: 10.1080/13873954.2023.2184835
File-URL: http://hdl.handle.net/10.1080/13873954.2023.2184835
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Handle: RePEc:taf:nmcmxx:v:29:y:2023:i:1:p:95-115
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# input file: NMCM_A_2243087_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231203T183118 git hash: be90730853
Author-Name: Olusegun J. Ilegbusi
Author-X-Name-First: Olusegun J.
Author-X-Name-Last: Ilegbusi
Author-Name: Adnan Islam
Author-X-Name-First: Adnan
Author-X-Name-Last: Islam
Author-Name: Anand P. Santhanam
Author-X-Name-First: Anand P.
Author-X-Name-Last: Santhanam
Title: Computational modelling of airflow in distal airways using hybrid lung model
Abstract:
A major challenge in computational fluid dynamics (CFD) modelling of the human respiratory system is allowing for the variation of geometric scale. A methodology is proposed that enables CFD analysis from the middle through the distal airways to the alveolar level. The methodology relies on a hybrid lung geometry integrating a primary tracheobronchial tree (TBT) up to the fifth generation (section 1) and distal airway (section 2). Section 1 comprises of the middle airways reconstructed from patient CT scans. Section 2 comprises of the distal airway branching tree generated based on deterministic algorithm. The hybrid model allows the application of physiologically relevant boundary conditions in lieu of simplistic approximations used in previous studies. Two different breathing conditions are considered adapted from previous studies, representing resting and exercise activity. The predicted flow variables are assessed for numerical accuracy and validated by comparison with published experimental and numerical data.
Journal: Mathematical and Computer Modelling of Dynamical Systems
Pages: 186-207
Issue: 1
Volume: 29
Year: 2023
Month: 12
X-DOI: 10.1080/13873954.2023.2243087
File-URL: http://hdl.handle.net/10.1080/13873954.2023.2243087
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Handle: RePEc:taf:nmcmxx:v:29:y:2023:i:1:p:186-207