Thesis (MSc (Computer science))--University of Pretoria, 2008. / Includes bibliographical references (p. 143-147)

Thesis (M.S. in Modeling, Virtual Environments and Simulation (MOVES))--Naval Postgraduate School, Sept. 2004. / Thesis Advisor(s): Christian J. Darken. Includes bibliographical references (p. 93-95). Also available online.

Thesis (M.S. in Information Technology Management and M.S. in Computer Science)--Naval Postgraduate School, March 2005. / Thesis Advisor(s): Alexander Bordetsky, Gilbert M. Lundy. Includes bibliographical references (p. 69-75). Also available online.

The continuing trends of miniaturisation, mass customisation, globalisation and wide use of the Internet have great impacts upon manufacturing in the 21st century. Micro manufacturing will play an increasingly important role in bridging the gap between the traditional precision manufacturing and the emerging technologies like MEMS/NEMS. The key requirements for micro manufacturing in this context are hybrid manufacturing capability, modularity, reconfigurability, adaptability and energy/resource efficiency. The existing design approaches tend to have narrow scope and are largely limited to individual manufacturing processes and applications. The above requirements demand a fundamentally new approach to the future applications of micro manufacturing so as to obtain producibility, predictability and productivity covering the full process chains and value chains. A novel generic modular reconfigurable platform (GMRP) is proposed in such a context. The proposed GMRP is able to offer hybrid manufacturing capabilities, modularity, reconfigurablity and adaptivity as both an individual machine tool and a micro manufacturing system, and provides a cost effective solution to high value micro manufacturing in an agile, responsive and mass customisation manner. An integrated framework has been developed to assist the design of GMRPs due to their complexity. The framework incorporates theoretical GMRP model, design support system and extension interfaces. The GMRP model covers various relevant micro manufacturing processes and machine tool elements. The design support system includes a user-friendly interface, a design engine for design process and design evaluation, together with scalable design knowledge base and database. The functionalities of the framework can also be extended through the design support system interface, the GMRP interface and the application interface, i.e. linking to external hardware and/or software modules. The design support system provides a number of tools for the analysis and evaluation of the design solutions. The kinematic simulation of machine tools can be performed using the Virtual Reality toolbox in Matlab. A module has also been developed for the multiscale modelling, simulation and results analysis in Matlab. A number of different cutting parameters can be studied and the machining performance can be subsequently evaluated using this module. The mathematical models for a non-traditional micro manufacturing process, micro EDM, have been developed with the simulation performed using FEA. Various design theories and methodologies have been studied, and the axiomatic design theory has been selected because of its great power and simplicity. It has been applied in the conceptual design of GMRP and its design support system. The implementation of the design support system is carried out using Matlab, Java and XML technologies. The proposed GMRP and framework have been evaluated through case studies and experimental results.

Cette thèse présente Multichronia, un cadre conceptuel de simulation interactive fournissant une représentation visuelle du cheminement d'un utilisateur dans l'exploration des simulations d'un système complexe. En complément aux méthodes formelles d'analyse, Multichronia vise à aider ses utilisateurs à comprendre un système sous étude en fournissant quatre boucles interactives. La boucle d'exploration de l'espace des paramètres permet à un utilisateur de modifier des paramètres de simulation afin de tester des hypothèses. La boucle d'exploration de l'espace des simulations lui permet de manipuler les données correspondant à des instances de simulation. Notamment, elle rend disponible des opérations de sélection et d'alignement via une interface graphique. La boucle d'exploration de l'espace des données lui permet de transformer les flots de données. Finalement, la boucle d'exploration de l'espace visuel lui permet d'afficher des données et de manipuler leur aspect visuel. Afin de représenter le cheminement d'un utilisateur dans son exploration de l'espace des paramètres, une interface graphique a été développée. Il s'agit de Varbre multichro-nique, une vue formelle donnant une représentation informative de l'état de l'analyse d'un problème ainsi que la possibilité d'exécuter une foule d'opérations interactives. D'autre part, le cadre conceptuel Multichronia forme un pipeline de données générique allant d'un simulateur jusqu'à un logiciel d'analyse. Un modèle conceptuel peut être extrait de ce pipeline de même que le flux de données correspondant. Dans cette thèse, il a été spécialisé avec la technologie XML. Cette dernière permet entre autres de définir une méthodologie de conception du modèle de données associé à un simulateur. La mise en oeuvre de Multichronia a permis de vérifier la validité des concepts proposés. L'architecture logicielle adoptée est un cadre d'application, de sorte que de nouveaux simulateurs puissent être facilement exploités. Deux applications concrètes ont été implantées, soit la simulation tactique et stratégique de l'attaque de convois militaires. Des modifications mineures aux simulateurs ont été nécessaires afin qu'ils rencontrent certains critères établis dans cette thèse. Somme toute, ces applications ont montré que Multichronia peut être déployé pour des applications quelconques.

This diploma thesis deals with the question of simulation models. It is divided into the theoretical and practical part. The aim of the opening part, in which the fundamental theory is defined, is to familiarize the readers with the ideas and advantages which simulation models can offer. In its practical part the work already focuses on the particular simulation project which should point out the possibilities of utilization of these models in practice. The subject of this project is the simulation of the course of the cultural event in the O2 Arena stadium. The main goal of this project is creation of the authentic simulation model which would on the basis of the later analysis enable the elimination or optimalization of the predefined major problems that are connected with organizing big cultural events in this arena.

In this research, we developed an ontology based reuse infrastructure for trajectory simulation and investigated the use of ontologies and domain engineering practices to develop a formalized methodology to make use of the experience and knowledge leveraged from the past trajectory simulation projects. Trajectory simulation in this context is a computational tool to calculate the flight path and other parameters of munition such as its orientation or angular rates during its operation In this thesis, engineering knowledge to simulate the trajectory of a munition is captured in an ontology called Trajectory Simulation ONTology (TSONT). Concepts of trajectory simulation and the relation among these concepts are captured by using Web Ontology Language and presented as a domain model that is available for reuse. Using the formalized domain knowledge, reuse infrastructure specifications are constructed to enable the reuse of software artifacts for two main programming paradigms, which are object oriented programming and function oriented programming. UML and application frameworks are used when constructing for object oriented paradigm. And data flow diagrams are used to formalize the design of the function oriented simulations to compute the trajectory of munition. Object oriented and function oriented platform independent designs are constructed to specify the infrastructure using the knowledge captured in TSONT and made available for reuse. With constructing two different designs for two different paradigms by using the same domain model, evidence of knowledge reuse were produced. Three different case studies were carried out as infrastructure implementation. In the first case study, an object oriented application framework was developed in MATLAB for six degrees of freedom trajectory simulation using platform independent object oriented design. This framework is reused to develop two different simulations. Using the developed framework for two applications produced evidence of code reuse. In the second case, a point mass trajectory simulation framework is designed to be implemented in C# reusing the same platform independent object oriented design. This case produced the evidence of design reuse. In the last case study, a MATLAB Simulink Blockset is developed for point mass unguided trajectory simulations and two different simulations are built using the Blockset. By this case, we collected the evidence of code reuse also in function oriented paradigm.

This monograph contributes to the methodology of Agent-based Computational Economics. First, we introduce a generic simulation framework suitable for agent-based simulations featuring the support of heterogeneous agents, hierarchical scheduling, and flexible specification of design parameters. For the latter, we use an XML-based format enabling the design of flexible models, with the possibility of varying both agent population and parameterization. Further, the tool allows the definition of communication channels to single agents, or groups thereof, and handles the information exchange. Both agents and communication channels can be added and removed at runtime. To handle the heterogeneity arising from both the agents' implementations and the underlying platforms, we introduce an XML-based wrapper technique for mapping the functionality of agents living in an interpreter-based environment to a standardized JAVA interface. Second, we present a collection of artificial economic actors to be used with this framework. Their interplay is demonstrated in two fields of management science: marketing and technological choice. In the field of marketing, the question of choosing the optimal segmentation techniques for market segmentation is investigated, comparing the performance of firm agents with diverse segmentation strategies in a highly customizable artificial consumer market. In the second application, we study the influence of technological efficiency and organizational inertia on the emergence of competition when firms decide myopically. We observe the competitive reaction of a former monopolist to the advent of a new competitor to assess when new, "disruptive" technologies cause the failure of incumbent firms and investigate simple defensive strategies. (author's abstract)

The content of this diploma thesis is to create a simulation model of the logistics chain of the production area of an industrial plant in order to design the logic control of material flow. Plant Simulation software from the company Siemens PLM Software is used to create the simulation model. The diploma thesis consists of system analysis of the researched area of the production plant. With the help of the simulation model, simulation experiments and evaluation of the obtained results are made. According to the results, the conclusions are drawn.

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