Showing papers on "Modeling and simulation published in 2007"

Modeling and Simulation of Electric and Hybrid Vehicles

Abstract: This paper discusses the need for modeling and simulation of electric and hybrid vehicles. Different modeling methods such as physics-based Resistive Companion Form technique and Bond Graph method are presented with powertrain component and system modeling examples. The modeling and simulation capabilities of existing tools such as Powertrain System Analysis Toolkit (PSAT), ADvanced VehIcle SimulatOR (ADVISOR), PSIM, and Virtual Test Bed are demonstrated through application examples. Since power electronics is indispensable in hybrid vehicles, the issue of numerical oscillations in dynamic simulations involving power electronics is briefly addressed

A Simple, Effective Lead-Acid Battery Modeling Process for Electrical System Component Selection

Abstract: Electrical system capacity determination for conventional vehicles can be expensive due to repetitive empirical vehicle-level testing. Electrical system modeling and simulation have been proposed to reduce the amount of physical testing necessary for component selection [1, 2].

Handbook of Dynamic System Modeling

Abstract: INTRODUCTION The Languages of Dynamic System Modeling by Paul A. Fishwick Introduction Dynamic System Modeling Examples Taxonomic Approaches Language Syntax Semantics Pragmatics Summary The Dynamics of the Computational Modeling of Analogy-Making by Robert M. French Introduction Analogy-Making as Sameness Analogy-Making as a Means of "Bootstrapping" Cognition The Necessity of Malleable Representations The Dynamics of Representation-Building in Analogy-Making Context-Dependent Computational Temperature Interaction between Top-Down and Bottom-Up Processes: An Example Computational Models Implementing This Bottom-Up/Top-Down Interaction Architectural Principles How This Type of Program Works: The Details How Tabletop Finds a Reasonable Solution The Issue of Scaling Up The Potential Long-Term Impact of the Mechanisms Presented Conclusions Impact of the Semantic Web on Modeling and Simulation by John A. Miller, Congzhou He, and Julia I. Couto Introduction Semantic Web: Relevant Issues Conceptual Basis for Discrete-Event Simulation Types of Mathematical Models Adding Semantics to Simulation Models Overview of DeSO Overview of DeMO Summary Systems Engineering by Andrew P. Sage Introduction Systems Engineering The Importance of Technical Direction and Systems Management Other Parts of the Story Summary Basic Elements of Mathematical Modeling by Clive L. Dym Principles of Mathematical Modeling Dimensional Consistency and Dimensional Analysis Abstraction and Scale Conservation and Balance Principles The Role of Linearity Conclusions DEVS Formalism for Modeling of Discrete-Event Systems by Tag Gon Kim Introduction System-Theoretic DES Modeling DEVS Formalism for DES Modeling DES Analysis with DEVS Model Simulation of DEVS Model Conclusion MODELING METHODOLOGIES Domain-Specific Modeling by Jeff Gray, Juha-Pekka Tolvanen, Steven Kelly, Anirudda Gokhale, Sandeep Neema, and Jonathan Sprinkle Introduction Essential Components of a Domain-Specific Modeling Environment Case Studies in DSM Overview of Supporting Tools Conclusion Agent-Oriented Modeling in Simulation: Agents for Modeling and Modeling for Agents by Adelinde M. Uhrmacher and Mathias Rohl Introduction Agents for Modeling in Simulation Modeling and Simulation for Agents Conclusion Distributed Modeling by Simon J.E. Taylor Introduction Modeling with COTS Simulation Packages Distributed Simulation CSP-Based Distributed Simulation A Standards-Based Approach Case Study Conclusion Model Execution by Kalyan S. Perumalla Introduction Time-Stepped Execution Discrete-Event Execution Summary Discrete-Event Simulation of Continuous Systems by James Nutaro Introduction Simulating a Single Ordinary Differential Equation Simulating Coupled Ordinary Differential Equations DEVS Representation of Discrete-Event Integrators The Heat Equation Conservation Laws Two-Point Integration Schemes Conclusions MULTIOBJECT AND SYSTEM Toward a Multimodel Hierarchy to Support Multiscale Simulation by Mark S. Shephard, E. Seegyoung Seol, and Benjamin FrantzDale Introduction Functional and Information Hierarchies in Multiscale Simulation Constructing a Multimodel: Design of Functional Components to Support Multiscale Simulations Example Multimodel Simulation Procedures Closing Remarks Finite Elements by Marc Hoit and Gary Consolazio Finite Element Theory Membrane Elements Flat Plate and Shell Elements Solid Elements Dynamics Summary Multimodeling by Minho Park, Paul A. Fishwick, and Jinho Lee Introduction Scene Construction Multimodeling Exchange Language (MXL) Dynamic Exchange Language (DXL) A Boiling Water Example Conclusion Hybrid Dynamic Systems: Modeling and Execution by Pieter J. Mosterman Introduction Hybrid Dynamic Systems Hybrid Dynamic System Behaviors An Implementation Advanced Topics in Hybrid Dynamic System Simulation Pathological Behavior Classes Conclusions Theory and Practice for Simulation Interconnection: Interoperability and Composability in Defense Simulation by Ernest H. Page Introduction The Practice of Simulation Interconnection-Simulation Interoperability The Theory of Simulation Interconnection-Simulation Composability Conclusions MODEL TYPES Ordinary Differential Equations by Francisco Esquembre and Wolfgang Christian Introduction Numerical Solution Taylor Methods Runge-Kutta Methods Implementation Adaptive Step Implementation of Adaptive Step Performance and Other Methods State Events The OSP Library Difference Equations as Discrete Dynamical Systems by Hassan Sedaghat Introduction Basic Concepts First-Order Difference Equations Higher Order Difference Equations Process Algebra by J.C.M. Baeten, D.A. van Beek, and J.E. Rooda Introduction Syntax and Informal Semantics of the ? Process Algebra Algebraic Reasoning and Verification Conclusions Temporal Logic by Antony Galton Propositional Logic Introducing Temporal Logic Syntax and Semantics Models of Time Further Extensions to the Formal Language Illustrative Examples Conclusion Further Reading Modeling Dynamic Systems with Cellular Automata by Peter M.A. Sloot and Altons G. Hoekstra Introduction A Bit of History Cellular Automata to Model Dynamical Systems One-Dimensional CAs Lattice Gas Cellular Automata Models of Fluid Dynamics Spatio-Temporal Connectionist Networks by Stefan C. Kremer Introduction Connectionist Networks (CNs) Spatio-Temporal Connectionist Networks Representational Power Learning Applications Conclusion Modeling Causality with Event Relationship Graphs by Lee Schruben Introduction Background and Definitions Enrichments to Event Relations Graphs Relationships to Other Discrete-Event System Modeling Methods Simulation of Event Relationship Graphs Event Relationship Graph Analysis Experimenting with ERGs Petri Nets for Dynamic Event-Driven System Modeling by Jiacun Wang Introduction Petri Net Definition Transition Firing Modeling Power Petri Net Properties Analysis of Petri Nets Colored Petri Nets Timed Petri Nets Concluding Remark Queueing System Models by Christos G. Cassandras Introduction Specification of Queueing System Models Performance of a Queueing System Queueing System Dynamics Little's Law Simple Markovian Queueing Models Markovian Queueing Networks Non-Markovian Queueing Systems Port-Based Modeling of Engineering Systems in Terms of Bond Graphs by Peter Breedveld Introduction Structured Systems: Physical Components and Interaction Bond Graphs Multiport Generalizations Conclusion System Dynamics Modeling of Environmental Systems by Andrew Ford Introductory Examples Comparison of the Flowers and Sales Models Background on Daisy World The Daisy World Model The Daisy World Management Flight Simulator Dynamic Simulation with Energy Systems Language by Clay L. Montague Introduction Reading an Energy Systems Language Diagram Translating a Diagram to Dynamic Equations Calibration of Model Constants Preparation for Simulation Dynamic Output of the Marsh Sector Model A Brief Comparison with Forrester's Systems Dynamics Approach Conclusions Ecological Modeling and Simulation: From Historical Development to Individual-Based Modeling by David R.C. Hill and P. Coquillard Introduction An Old Story? Determinism or Probability? Modeling Techniques The Use of Models in Ecology Models Are Scientific Instruments Levels of Organization and Methodological Choices Individual-Based Models Applications Conclusion Ontology-Based Simulation in Agriculture and Natural Resources by Howard Beck, Rohit Badal, and Yunchul Jung Introduction Ways in Which Ontologies Can Be Applied to Simulation How to Build an Ontology-Based Simulation-Bioprocessing Example Tools for Ontology-Based Simulation Conclusions Modeling Human Interaction in Organizational Systems by Stewart Robinson Introduction Systems and Human Interaction Why Model Human Interaction? Modeling Human Interaction: Research and Practice The KBI Methodology A Case Study: Modeling Human Decision Making at Ford Motor Company Conclusion Military Modeling by Roger Smith Introduction Applications Representation Dynamics Modeling Approach Military Simulation Systems Conclusion Dynamic Modeling in Management Science by Michael Pidd Introduction An Approach to Dynamic Systems Modeling in Management Science Discrete Event Simulation System Dynamics in Management Science Model Validation Chapter Summary Modeling and Analysis of Manufacturing Systems by E. Lefeber and J.E. Rooda Introduction Preliminaries Analytical Models for Steady-State Analysis Discrete-Event Models Effective Process Times Control of Manufacturing Systems: A Framework Standard Fluid Model and Extensions Flow Models Conclusions Sensor Network Component-Based Simulator by Boleslaw K. Szymanski and Gilbert Gang Chen The Need for a New Sensor Network Simulator Component Simulation Toolkit Wireless Sensor Network Simulation Conclusions CASE STUDIES Multidomain Modeling with Modelica by Martin Otter, Hilding Elmqvist, and Sven Erik Mattsson Modelica Overview Modelica Basics Modelica Libraries Symbolic Processing of Modelica Models Outlook Acknowledgments On Simulation of Simulink(R) Models for Model-Based Design by Rohit Shenoy, Brian McKay, and Pieter J. Mosterman Introduction The Case Study Example Designing with Simulation Obtaining Computational Models The Robotic Arm Model Using Computational Models for Control Design Testing with Model-Based Design Conclusions

Integrated Hybrid-Simulation of Electric Power and Communications Systems

Abstract: The modern power grid is strongly integrated with its communication network. While a power system primarily consists of elements that are modeled by continuous equations, a communication system has discrete event dynamics. We model the integrated operation of these two systems with a hybrid modeling and simulation technique. Systematically combining continuous and discrete event system models is necessary for correctly simulating critical system behaviors. This paper discusses an approach based on the discrete event system specification (DEVS) that characterizes the interaction of the two systems formally to preserve simulation correctness. We demonstrate the implementation of our integrated hybrid simulation technique with detailed generator and network models in a wide-area cooperative automatic load-control scenario.

Modeling and Simulation of Airship Dynamics

Abstract: This paper proposes a modeling approach for the nonlinear dynamics simulation of airships. The flight mechanics, aerostatics, and aerodynamics are incorporated into the model. A comprehensive estimation method is provided for the aerodynamics, including added-mass terms, viscous effect, forces on the fins, forces on the hull due to the fins, and axial drag. A simulation program is developed from the dynamics model and applied to analyze the control responses of the Skyship-500 airship. A comparison between the simulation and flight test results for different control inputs shows that the dynamics simulation gives a reasonable estimation of the flight behavior. The dynamics model is then linearized using a finite difference approach and the linear model is applied to investigate the stability of longitudinal and lateral motion at various speeds. With the trust gained from validation, the dynamics model and simulation program can be used to evaluate the flight and control performance of other airships.

A framework for system-level modeling and simulation of embedded systems architectures

Abstract: The high complexity of modern embedded systems impels designers of such systems to model and simulate system components and their interactions in the early design stages. It is therefore essential to develop good tools for exploring a wide range of design choices at these early stages, where the design space is very large. This paper provides an overview of our system-level modeling and simulation environment, Sesame, which aims at efficient design space exploration of embedded multimedia system architectures. Taking Sesame as a basis, we discuss many important key concepts in early systems evaluation, such as Y-chart-based systems modeling, design space pruning and exploration, trace-driven cosimulation, and model calibration.

Agent-directed simulation systems engineering

Abstract: This article emphasizes the application of system engineering principles to the development of Modeling and Simulation (M&S) applications. Clear distinction between M&S for system engineering and system engineering (SE) for M&S is presented to clarify the need for simulation system engineering. Furthermore, the characteristics of emergent open, complex, and adaptive M&S applications are overviewed to make the case for agent-directed simulation system engineering. An agent-directed simulation view of developing such applications is presented within the framework of a cognitive system engineering perspective.

Integrated heat air and moisture modeling and simulation

Abstract: An overall objective of our work is to improve building and systems performances in terms of durability, comfort and economics. In order to predict, improve and meet a certain set of performance requirements related to the indoor climate of buildings, the associated energy demand, the heating, venting and air conditioning systems and the durability of the building and its interior, simulation tools are indispensable. In the field of heat, air and moisture transport in building and systems, much progress on the modeling and simulation tools has been established. However, the use of these tools in an integrated building simulation environment is still limited. Also a lot of modeling work has been done for energy related building systems, such as solar systems, heat pump systems and heat storage systems. Often, these models focus on the systems and not on the coupled problem of building and systems. This thesis presents the development and evaluation of an integrated heat, air and moisture simulation environment for modeling and simulating dynamic heat, air and moisture processes in buildings and systems. All models are implemented in the computational software package MatLab with the use of SimuLink and Comsol. The main advantages of this approach are: First, the simulation environment is promising in solving both time and spatial related multi-scale problems. Second, the simulation environment facilitates flexible linking of models. Third, the environment is transparent, so the implementation of models is relatively easy. It offers a way to further improve the usage and exchange of already developed models of involved parties. More than 25 different heat, air and moisture related models are included in this work. Most of the models are successfully verified (by analytical solutions or by comparison with other simulation results) and/or validated (by experimental data). The use of the simulation environment regarding design problems is demonstrated with case studies. Overall is concluded that the simulation environment is capable of solving a large range of integrated heat, air and moisture problems. Furthermore, it is promising in solving current modeling problems caused by either the difference in time constants between heating venting and air conditioning components and the building response or problems caused by the lack of building simulation tools that include 2D and 3D detail simulation capabilities. The case studies presented in this thesis show that the simulation environment can be a very useful tool for solving performance-based design problems.

Real-Time Digital Time-Varying Harmonic Modeling and Simulation Techniques IEEE Task Force on Harmonics Modeling and Simulation

Abstract: With the growing importance of power quality problems to electric utilities and customers, there is an increased focus on the search for new tools and techniques for accurate analysis and resolution of such problems. This paper reviews currently available techniques for the modeling and simulation of time-varying harmonics in real-time. Following a brief summary of the currently used off-line harmonics modeling and simulation methods, the principles and system element representations using wave digital filter (WDF) and discrete wavelet transform (DWT) methods are discussed. Hardware and software architectures of real-time network simulator (RTNS), HYPERSIM, and PC-cluster based real-time simulator are presented. Towards the end, two case studies are given to demonstrate the real-time analysis of time-varying harmonics generated by a three-phase arc furnace using the PC-cluster based real-time simulator, and a real-time hardware-in-the-loop (HIL) equipment testing using the real-time digital simulator (RTDS)

Stochastic Modeling and Simulation of Frequency-Correlated Wideband Fading Channels

Abstract: For the simulation of practical frequency-diversity wireless communication systems, such as frequency-hopping systems, multicarrier code-division multiple-access systems, and orthogonal frequency-division multiplexing systems, it is often desirable to produce multiple Rayleigh fading processes with given frequency correlation properties. In this paper, a novel stochastic wide-sense stationary sum-of-sinusoids channel simulator is proposed to emulate frequency-correlated wideband fading channels, where the frequency correlation properties are controlled by only adjusting the constant phases. Closed-form expressions are provided for all the parameters of the simulation model. This enables us to investigate analytically the overall correlation properties (not only the correlation coefficients) of the simulated processes with respect to both time separation and frequency separation. It is shown that the wideband channel simulator will be reduced to a narrowband Rayleigh fading-channel simulator by removing the frequency selectivity. Furthermore, the COST 207 typical-urban and rural-area channels are applied to evaluate the performance of the resulting wideband and narrowband channel simulators, respectively. The correlation properties of the simulation models approach the desired ones of the underlying reference models as the number of exponential functions tends to infinity, while very good approximations are achieved with the chosen limited number of exponential functions

Stochastic modeling and simulation of gene networks - A review of the state-of-the-art research on stochastic simulations

Abstract: This paper provides a comprehensive review of the state-of-the-art research on stochastic simulations. It stimulates the interest of tackling the problem of stochastic simulation using statistical signal processing methods, as well as innovative thinking of stochastic modeling of gene networks from the viewpoint of signal processing

A review of current issues in air pollution modeling and simulation

Abstract: Air pollution modeling is now a mature field, and comprehensive numerical models (the chemistry-transport models) are used in many applications. This article aims at reviewing the main issues from the point of view of applied mathematics and computational physics (as viewed by the author). We address topics such as subgrid parameterization, numerical algorithms with a focus on aerosol simulation, data assimilation and inverse modeling, reduction of high-dimensional models and propagation of uncertainties. Even if this article is strictly related to air pollution modeling, many issues and methods can be extended to dispersion of tracers in other media (for instance, water).

Modeling and simulation of individual user behavior for building performance predictions

Abstract: User behavior is a key to the correct prediction of building performance. Performance is meant here not only in relation to energy consumption, but more importantly to user satisfaction and, in commercial buildings, job performance. The contributions of this paper are static and dynamic models of individual users and user activities in an office environment in relation to building control systems. The models are based on a well structured general model of five different domains of building entities, including user activities. Models for specific simulation projects are refinements of this general model. It is shown how multi-agent based simulations can be automatically derived from such models. A case study of an university office with irregular occupancy is introduced as an example.

Multi-Accuracy Power and Performance Transaction-Level Modeling

Abstract: This paper introduces a modeling and simulation technique that extends transaction-level modeling (TLM) to support multi-accuracy models and power estimation. This approach provides different combinations of power and performance models, and the switching of model accuracy during simulation, allowing the designer to trade off between simulation accuracy and speed at runtime. This is particularly useful during the exploration phase of a design, when the designer changes the features or the parameters of the design, trying to satisfy its constraints. Usually, only limited portions of a system are affected by a single parameter change, and therefore, it is possible to fast-simulate uninteresting sections of the application. In particular, we show how to extend the TLM and modify the SystemC kernel to support multi-accuracy features. The proposed methodology has been tested on several benchmarks, among which is an MPEG4 encoder, showing that simulation speed can be increased of one order of magnitude. On the same benchmarks, we also show how it is possible to choose the optimal performance simulation accuracy for a given power model, maximizing simulation speed for the desired accuracy.

Modeling and simulation of the pressing section of a paper machine

Abstract: We are concerned with modeling and simulation of the pressing section of a paper machine. We state a two-dimensional model of a press nip which takes into account elasticity and flow phenomena. Nonlinear filtration laws are incorporated into the flow model. We present a numerical solution algorithm and a numerical investigation of the model with special focus on inertia effects.

Modeling and simulation of piezoelectric mems energy harvesting device

Abstract: Piezoelectric MEMS power generator is used to harvest energy from the ambient vibrations in the environment. This paper proposes a structure design of MEMS power generator for low-frequency applications, which is based on bulk MEMS technology and (110) Si wafer. The structure consists of a silicon cantilever with a piezoelectric layer attached. The cantilever is modeled as an Euler-Bernoulli beam with a lumped mass beneath the tip of the cantilever, and then analytical modeling and simulations are carried out using MATLAB. Simulation results show that a tradeoff between the geometric parameters and the proof mass should be made for a high output power of the device. To increase the output power, the length of piezoelectric layer can be optimized, which is not necessarily equal to that of cantilever. Simulation results point out ways to perform the optimization of MEMS power generator. The analytical modeling and simulations are also helpful for the design of macro-scale power generator.

Reactive Flows, Diffusion and Transport

Abstract: The articles in this volume summarize the research results obtained in the former SFB 359 "Reactive Flow, Diffusion and Transport" which has been supported by the DFG over the period 1993-2004. The main subjects are physical-chemical processes sharing the difficulty of interacting diffusion, transport and reaction which cannot be considered separately. Typical examples are the chemical processes in flow reactors and in the catalytic combustion at surfaces. Further examples are models of star formation including diffusive mass transport, energy radiation and dust formation and the polluting transport in soil and waters. For these complex processes mathematical models are established and numerically simulated. The modeling uses multiscale techniques for nonlinear differential equations while for the numerical simulation and optimization goal-oriented mesh and model adaptivity, multigrid techniques and advanced Newton-type methods are developed combined with parallelization. This modeling and simulation is accompanied

Modeling and Simulation for Material Selection and Mechanical Design

Abstract: This reference describes advanced computer modeling and simulation procedures to predict material properties and component design including mechanical properties, microstructural evolution, and materials behavior and performance. The book illustrates the most effective modeling and simulation technologies relating to surface-engineered compounds, fastener design, quenching and tempering during heat treatment, and residual stresses and distortion during forging, casting, and heat treatment. Written by internationally recognized experts in the field, it enables researchers to enhance engineering processes and reduce production costs in materials and component development.

An Introduction to Modeling and Simulation of Particulate Flows (Computational Science and Engineering)

Abstract: Preface 1. Fundamentals 2. Modeling of particulate flows 3. Iterative solution schemes 4. Representative numerical simulations 5. Inverse problems/parameter identification 6. Extensions to 'swarm-like' systems 7. Advanced particulate flow models 8. Coupled particle/fluid interaction 9. Simple optical scattering methods for particulate media 10. Closing remarks Appendix A. Basic (continuum) fluid mechanics Appendix B. Scattering Bibliography Index.

Modelling and Simulation of Dynamic and Partially Reconfigurable Systems using SystemC

Abstract: An innovative technique to model and simulate partial and dynamic reconfiguration is presented in this paper Developed from modifications of the SystemC kernel, this technique can either be used at transaction level (TLM) or at register transfer level (RTL). At TLM it allows the modeling and simulation of higher-level hardware and embedded software, while at RTL the dynamic system behavior can be observed at signals level. The provided set of instructions promises a reduction in the design cycle. Compared with traditional strategies, information about dynamic and adaptive behavior will be available in an earlier stage,. An established application from the automotive domain is analyzed and illustrates the potential of the technique at TLM. The acquired results will assist in the choice of the best cost/benefit tradeoff regarding FPGA chip area.

Modeling and simulation of photovoltaic panel based on artificial neural networks and VHDL-language

Abstract: The number of electronic applications using artificial neural network-based (ANN) solutions has increased considerably in the last few years. However, the ANN- application in photovoltaic systems is very limited. This paper introduces the preliminary result of the modeling and simulation of photovoltaic panel based on ANN and VHDL-language. In fact, an experimental database of meteorological data (irradiation, temperature) and output electrical generation signals of the PV-panel (current and voltage) has been used in this study. The inputs of the ANN-PV-panel are the daily total irradiation and mean average temperature while the outputs are the current and voltage generated from the panel. Firstly, a dataset of 4 x 364 have been used for training the network and then one year is used for testing the ANN model. Subsequently, the neural network (MLP) corresponding to PV-panel is implemented using VHDL language based on the saved weights and bias of the network. Simulation results of the trained MLP-PV panel based on Matlab and VHDL are presented. The proposed PV-panel model based ANN and VHDL permit to evaluate the performance PV-panel using only the environmental factors and involves less computational efforts, and it can be used for predicting the output electrical energy from the PV-panel.

Real-Time and Off-Line Simulation of a Detailed Wind Farm Model Connected to a Multi-Bus Network

Abstract: This paper describes the detailed modeling and simulation of a wind farm composed of eight doubly-fed induction generators (DFIG) connected to a 24-bus electrical network Once built, the model was brought to real-time using the eMEGAsim, a Simulink-based, distributed real-time simulator of electrical power systems Then, analysis of the steady-state and transient response of the system is made Finally, the paper concludes with a discussion on the off-line performance and the real-time performance on the eMEGAsim simulator

Agent-based modeling of interdependencies in critical infrastructures through UML

Abstract: In this paper, we investigate the adoption of agent-based modeling and simulation to study the interdependencies in critical infrastructures. We propose an approach to model critical infrastructures through agents as well as some guidelines to simulate such complex systems. We adopt UML as modeling language, thus proposing a new way to represent the interdependencies that occur in a complex system composed by different critical infrastructures. Through an example that regards an information system for civic emergency management, we describe our modeling methodology, discuss about the measurements and results that can be gained from the simulation of the complex system, and present the most relevant issues regarding the simulator design and implementation.