Thesis (M.S.)--Georgia State University, 2007. / Title from file title page. Xiaolin Hu, committee chair; Rajshekhar Sunderraman, Ying Zhu, committee members. Electronic text (71 p. : ill. (some col.)) : digital, PDF file. Description based on contents viewed Jan. 29, 2008. Includes bibliographical references (p. 70-71).

Thèse doctorat : Génie Civil : INSA LYON : 2002. / Titre provenant de l'écran-titre. Bibliogr. p. 201-206.

Thesis--Ph. D., University of Hong Kong. / Contents: v.1. Text.- v.2. Appendices. Typewritten.

The Department of Defense has always had an interest in simulation systems for training and analysis. Recently, simulation usage in training has been stressed. Simulation systems provide an easy and effective way for trainees to learn military doctrine and small unit tactics. In order to be effective, a simulation must accurately represent the real world. Sensory perception is one important real world influence that should be modeled. Modular Semi-Automated Forces (ModSAF) is a highly advanced computer simulation system that can model the movement, formations, equipment and other aspects of armed forces with precise calculations. In spite of all of the advances in ModSAF and other systems like it, the behaviors of sound and how they affect the warfighter have been scarcely modeled. The goal of this project is to investigate how sound is produced, propagated, and detected (acoustics), the behavioral effects sound has on the human psyche, and model the findings. It includes the development of a computer model of the physical phenomenon relating to sound, to be incorporated within ModSAF or another similar constructive simulation system.

The aim of this thesis is to create simulation model of a conveyor node in the field of sequential stack topcoat paintshop of ŠKODA AUTO a.s. in Mladá Boleslav. Simulation model is create in Plant Simulation. The chapters of this thesis describes the overview of conveying technology used for the transportation of bodies in the solved area, basics of discrete simulation, describe solved area and process of creation a simulation model. Using the simulation model is tested overall throughput of solved area, when changes input parameters. From results of experiments are deducted the conclusions.

This work focuses on simulation of core blowing into the core boxes. Mechanical production of cores is now a normal part of any foundry. But can never predict whether core can make right the first time. This situation can be used as a helper QuikCAST simulation program that is able to handle the issue and deal with and can find the optimal basis.

The goal of the thesis is to develop tools for improving shipbuilding workshops productivity. These tools have been tested on workshops of Aker Yards France shipyard, in Saint-Nazaire. The main chapter concerns the modelling of a workshop with the discrete-event simulation methodology. Production simulation is strongly used in some fields as automobile industry but is less used in shipbuilding. Indeed, the difficulty is that almost each piece to produce is unique. The objective is to show the importance of production simulation for such workshops. The modelled workshop is linked to a genetic algorithm to improve its productivity by optimizing its production sequence. Secondly a tool of creation and optimization of PERT networks has been created. The tool contains a graphical interface to easily handle networks and an optimization algorithm. This last one can minimize total cost of any project for a given total time. The tool has been linked to the modelled workshop. Consequently we get a PERT diagram of the workshop that can highlight critical activities. Finally, the last chapter explains the development of a tool to solve space allocation problems. Indeed space is often a critical point in many shipyards. Thanks to a user-friendly interface, the developed tool facilitates scheduling of these workshops. Furthermore it contains an optimization algorithm based on a heuristic approach to automate the planning process. In conclusion a set of efficient tools has been carried out with concrete applications on real workshops./Lobjectif de la thèse est de développer une série doutils qui permettent doptimiser la production dateliers de construction navale. Ces outils sont testés sur des ateliers du Chantier Naval Aker Yards France à Saint-Nazaire. Le chapitre principal traite de la modélisation dun atelier dit de PréPréFabrication sur le principe de la simulation de production à évènements discrets. La simulation de production est fortement utilisée dans certains domaines industrie automobile par exemple mais encore peu souvent en construction navale. En effet, la difficulté réside dans la diversité des pièces à produire. Lobjectif est de démontrer lintérêt de la simulation de production même dans ces ateliers où pratiquement chaque pièce à construire est unique. Latelier modélisé a été couplé avec un algorithme génétique pour améliorer sa productivité en optimisant la séquence de production. En second lieu, un outil de création et doptimisation des réseaux PERT a été créé. Loutil contient une interface graphique permettant une manipulation aisée des réseaux et un algorithme doptimisation. Ce dernier permet de minimiser le coût de réalisation dun projet pour un temps total fixé. En étant couplé avec le logiciel de simulation développé, une création automatique du diagramme PERT de latelier est créée, permettant de mettre clairement en évidence ses activités critiques. Finalement, le dernier chapitre de la thèse porte sur la création dun logiciel permettant de résoudre les problèmes de gestion de surface et de planification rencontrés dans certains chantiers. En effet, lespace au sol est un élément critique pour beaucoup dateliers de construction navale. Le logiciel développé, grâce à une interface conviviale et pratique, permet de faciliter grandement la planification. De plus, il contient un algorithme doptimisation basé sur des heuristiques afin dautomatiser le processus de planification. En conclusion, un ensemble doutils efficaces a été généré, avec des applications concrètes sur des ateliers réels.

Healthcare problems are complex; they exhibit both detail and dynamic complexity. It has been argued that Discrete Event Simulation (DES), with its ability to capture detail, is ideal for problems exhibiting this type of complexity. On the other hand, System Dynamics (SD) with its focus on feedback and nonlinear relationships lends itself naturally to comprehend dynamic complexity. Although these modelling paradigms provide valuable insights, neither of them are proficient in capturing both detail and dynamic complexity to the same extent. It has been argued in literature that a hybrid approach, wherein SD and DES are integrated symbiotically, will provide more realistic picture of complex systems with fewer assumptions and less complexity. In spite of wide recognition of healthcare as a complex multi- dimensional system, there has not been any reported study which utilises hybrid simulation. This could be attributed to the fact that due to fundamental differences, the mixing of methodologies is quite challenging. In order to overcome these challenges a generic theoretical framework for hybrid simulation is required. However, there is presently no such generic framework which provides guidance about integration of SD and DES to form hybrid models. This research has attempted to provide such a framework for hybrid simulation which can be utilised in healthcare domain. On the basis of knowledge induced from literature, three requirements for the generic framework have been established. It is argued that the framework for hybrid simulation should be able to provide answers to Why (why hybrid simulation is required), What (what information is exchanged between SD and DES models) and How (how SD and DES models are going to interact with each other over the time to exchange information) within the context of implementation of hybrid simulation to different problem scenarios. In order to meet these requirements, a three-phase generic framework for hybrid simulation has been proposed. Each phase of the framework is mapped to an established requirement and provides guidelines for addressing that requirement. The proposed framework is then evaluated theoretically based on its ability to meet these requirements by using multiple cases, and accordingly modified. It is further evaluated empirically with a single case study comprising of Accident and Emergency department of a London district general hospital. The purpose of this empirical evaluation is to identify the limitations of the framework with regard to the implementation of hybrid models. It is realised during implementation that the modified framework has certain limitations pertaining to the exchange of information between SD and DES models. These limitations are reflected upon and addressed in the final framework. The main contribution of this thesis is the generic framework for hybrid simulation which has been applied within healthcare context. Through an extensive review of existing literature in hybrid simulation, the thesis has also contributed to knowledge in multi-method approaches. A further contribution is that this research has attempted to quantify the impact of intangible benefits of information systems into tangible business process improvements. It is expected that this work will encourage those engaged in simulation (e.g., researchers, practitioners, decision makers) to realise the potential of cross-fertilisation of the two simulation paradigms.

Literature on the modeling and simulation of complex adaptive systems (cas) has primarily advanced vertically in different scientific domains with scientists developing a variety of domain-specific approaches and applications. However, while cas researchers are inherently interested in an interdisciplinary comparison of models, to the best of our knowledge, there is currently no single unified framework for facilitating the development, comparison, communication and validation of models across different scientific domains. In this thesis, we propose first steps towards such a unified framework using a combination of agent-based and complex network-based modeling approaches and guidelines formulated in the form of a set of four levels of usage, which allow multidisciplinary researchers to adopt a suitable framework level on the basis of available data types, their research study objectives and expected outcomes, thus allowing them to better plan and conduct their respective research case studies. Firstly, the complex network modeling level of the proposed framework entails the development of appropriate complex network models for the case where interaction data of cas components is available, with the aim of detecting emergent patterns in the cas under study. The exploratory agent-based modeling level of the proposed framework allows for the development of proof-of-concept models for the cas system, primarily for purposes of exploring feasibility of further research. Descriptive agent-based modeling level of the proposed framework allows for the use of a formal step-by-step approach for developing agent-based models coupled with a quantitative complex network and pseudocode-based specification of the model, which will, in turn, facilitate interdisciplinary cas model comparison and knowledge transfer. Finally, the validated agent-based modeling level of the proposed framework is concerned with the building of in-simulation verification and validation of agent-based models using a proposed Virtual Overlay Multiagent System approach for use in a systematic team-oriented approach to developing models. The proposed framework is evaluated and validated using seven detailed case study examples selected from various scientific domains including ecology, social sciences and a range of complex adaptive communication networks. The successful case studies demonstrate the potential of the framework in appealing to multidisciplinary researchers as a methodological approach to the modeling and simulation of cas by facilitating effective communication and knowledge transfer across scientific disciplines without the requirement of extensive learning curves.

This project presents an investigation into the viability of alternative knowl- edge acquisition strategies in knowledge management systems. The goal of this project is to illustrate that alternative means of knowledge acquisition can have a significant effect on the quality of the knowledge base. To accomplish this a modification of a wiki system, dubbed Prometheus, is proposed that uses a threshold based user vote acquisition mechanism. A simulation approach is used to compare a model of the Prometheus system against a model of a standard wiki system. A simulation framework is described that facilitates comparison between models of knowledge systems. The simu- lation framework is used to compare the knowledge systems in three different scenarios in an attempt to determine the conditions in which the Prometheus system may produce a higher quality knowledge base. The results of these ex- periments are presented along with some discussion and areas for future work.