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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

An HLA-based Simulation Environment for Virtual Reality via Java3D

Hsia, Wen-yang 28 August 2001 (has links)
The enforcement of reusability and shareability of products or components based on new technology standards for simulation and modeling is of paramount importance. In this thesis we first utilize DMSO HLA as the basic fundamental to design a customization environment for Web-based modeling and simulation. The environment is able to offer the interoperability framework between a broad spectrum of simulation paradigms, including both real-time and logical time models and to support a huge number of participants. To fulfill the goal we proposed three main tasks to be done. First, we proposed the mechanism to reduce the communication overhead and to balance the information consistency among large participants by incorporating a three-level control mechanism and Dynamic Filtering Strategy (DFS) within HLA RTI. In the second task, we proposed a load balancing algorithm to efficiently utilize the resource over the network environment. At the last task we use Java 3D to build a virtual reality application on the environment.
2

Pedestrian Leadership and Egress Assistance Simulation Environment (PLEASE)

Feuz, Kyle D. 01 December 2011 (has links)
Over the past decade, researchers have been developing new ways to model pedestrian egress especially in emergency situations. The traditional methods of modeling pedestrian egress, including ow-based modeling and cellular automata, have been shown to be poor models of human behavior at an individual level, as well as failing to capture many important group social behaviors of pedestrians. This has led to the exploration of agent-based modeling for crowd simulations including those involving pedestrian egress. Using this model, we evaluate different heuristic functions for predicting good egress routes for a variety of real building layouts. We also introduce reinforcement learning as a means to represent individualized pedestrian route knowledge. Finally, we implement a group formation technique, which allows pedestrians in a group to share route knowledge and reach a consensus in route selection. Using the group formation technique, we consider the effects such knowledge sharing and consensus mechanisms have on pedestrian egress times.
3

Softwear: A Flexible Design Framework For Electronic Textile Systems

Zeh, Christopher Michael 12 June 2006 (has links)
Because of their ubiquity and low cost fabrication techniques, electronic textiles (e-textiles) are an excellent platform for pervasive computing. Many e-textile applications are already available in the commercial, military, and academic domains, but most are very highly specialized and do not lend themselves easily to reuse or alteration. The purpose of this work is threefold: development of a methodology for building flexible and reusable applications that facilitates their use in the evolution of more complex systems, creation of a resource manager that realizes the methodology and enforces quality of service guarantees on tightly constrained textile resources, and construction of a simulation environment that allows for the rapid development and reconfiguration of systems to circumvent the need for the expensive physical prototyping process. This work discuss the effectiveness and appropriateness of the deployed event-driven hierarchical service model for application development. Additionally, this work explores the results of providing fault tolerance and quality of service guarantees in a textile environment that is particularly susceptible to faults. Further addressed by this work is the success of rapid prototyping and evaluation of applications in the simulation environment. / Master of Science
4

ASDA: um ambiente de simulação distribuída automático / ASDA: an automatic distributed simulation environment

Bruschi, Sarita Mazzini 25 November 2002 (has links)
Esta tese propõe um ambiente automático para desenvolvimento de simulação distribuída ASDA (Ambiente de Simulação Distribuída Automático), que tem como objetivo principal facilitar a utilização e desenvolvimento de simulação distribuída. As funcionalidades definidas no ASDA tornam-o diferente de todos os outros ambientes encontrados na literatura. A especificação do ASDA foi realizada através de um diagrama modular composto por sete módulos e também com o auxílio da ferramenta UML (Unified Modelling Language), através da utilização de três de seus diagramas: de casos de uso, de classes e de atividades. O ASDA permite aos usuários a utilização de simulação distribuída através da definição de uma nova simulação ou da replicação de um programa de simulação já desenvolvido. Se a opção for pelo desenvolvimento de um novo programa de simulação, o usuário deve fornecer o modelo e os parâmetros e o ambiente se encarrega de gerar o código do programa de simulação utilizando a abordagem que proporciona o melhor desempenho, levando em consideração as características do modelo e da plataforma. Além da especificação do ASDA, esta tese definiu um protótipo do ambiente com o objetivo de mostrar sua viabilidade de utilização. Neste protótipo, três módulos foram implementados, destacando-se o módulo Replicador, que utiliza a abordagem MRIP (Multiple Replication in Parallel). Esta tese contribui também com a definição de algumas diretrizes para a utilização da abordagem MRIP. A base para essa definição foram os resultados obtidos com a utilização do módulo Replicador / This thesis proposes an automatic environment for the development of distributed simulation ASDA (Ambiente de Simulação Distribuída Automático (in Portuguese), whose main goal is to make easier the use and development of distributed simulation. The ASDA functionality makes it different from all other environments found in the literature. The ASDA has been specified through a modular diagram, composed of seven modules built with the help of the UML (Unified Modelling Language) tool, using three of its diagrams: use case, class and activity. ASDA users can define the distributed simulation by means of the specification of a new simulation program or the replication of a simulation program already developed. If the user chooses to develop a new simulation program, he must only provide the model and the parameters. The environment will then generate the simulation program code using the approach that provides the best performance considering the model and platform characteristics. Besides the specification, this thesis presents a prototype of the ASDA environment with the goal of showing its viability. Three modules have been implemented for the prototype, highlighting the Replication module, which uses the MRIP (Multiple Replication in Parallel) approach. Another contribution of this thesis is the definition of a set of guidelines to the utilization of the MRIP approach. The basis to define these procedures was the results obtained with the utilization of the Replication module
5

Análise de desempenho de algoritmos de escalonamento de tarefas em grids computacionais usando simuladores. / Performance analysis of task scheduling algorithms in grid computing using simulators.

Rodamilans, Charles Boulhosa 10 February 2009 (has links)
Escalonamento em Grid tem sido vastamente estudado devido à sua grande importância para o desempenho da Grid. Dada a sua complexidade, este é subdividido em escalonamento de recursos e de aplicações. A qualidade do escalonamento está relacionada ao algoritmo de escalonamento de tarefas. O presente trabalho tem como objetivo apresentar a metodologia AGSA (Analysis of Grid Scheduling Algorithms) para a comparação de algoritmos de escalonamento de tarefas em Grid. O intuito desta metodologia é analisar o comportamento e desempenho dos algoritmos em diversos cenários. O ambiente de simulação CEGSE (Characterization oriEnted Grid Scheduling Environment) foi desenvolvido para a criação e simulação destes cenários. Os estudos de caso comprovam a eficácia da metodologia. / Grid Scheduling has been studied because it is very important for Grid performance. Due Grid Scheduling\'s complexity, it is subdivided in resource and application scheduling. The quality of scheduling is related a tasks scheduling algorithm. The dissertation presents the AGSA (Analysis of Grid Scheduling Algorithms) methodology for comparison of Grid Scheduling Algorithms in Grid Computing. The methodology purpose is the behavior and performance analysis of algorithms in various scenarios. The CEGSE (Characterization oriEnted Grid Scheduling Environment) simulation environment is developed for this scenarios create and simulate. The case studies ratify the methodology efficiency.
6

Análise de desempenho de algoritmos de escalonamento de tarefas em grids computacionais usando simuladores. / Performance analysis of task scheduling algorithms in grid computing using simulators.

Charles Boulhosa Rodamilans 10 February 2009 (has links)
Escalonamento em Grid tem sido vastamente estudado devido à sua grande importância para o desempenho da Grid. Dada a sua complexidade, este é subdividido em escalonamento de recursos e de aplicações. A qualidade do escalonamento está relacionada ao algoritmo de escalonamento de tarefas. O presente trabalho tem como objetivo apresentar a metodologia AGSA (Analysis of Grid Scheduling Algorithms) para a comparação de algoritmos de escalonamento de tarefas em Grid. O intuito desta metodologia é analisar o comportamento e desempenho dos algoritmos em diversos cenários. O ambiente de simulação CEGSE (Characterization oriEnted Grid Scheduling Environment) foi desenvolvido para a criação e simulação destes cenários. Os estudos de caso comprovam a eficácia da metodologia. / Grid Scheduling has been studied because it is very important for Grid performance. Due Grid Scheduling\'s complexity, it is subdivided in resource and application scheduling. The quality of scheduling is related a tasks scheduling algorithm. The dissertation presents the AGSA (Analysis of Grid Scheduling Algorithms) methodology for comparison of Grid Scheduling Algorithms in Grid Computing. The methodology purpose is the behavior and performance analysis of algorithms in various scenarios. The CEGSE (Characterization oriEnted Grid Scheduling Environment) simulation environment is developed for this scenarios create and simulate. The case studies ratify the methodology efficiency.
7

Coordination and Logistic Aspects in Computer Based Training for Emergency Situations

Nadeem, Hassam, Dastgeer, Usman January 2009 (has links)
<p>This report presents research study conducted at Linkoping University on coordination and logistics training design in simulation based environment.This study is based on C3Fire simulation environment for designing scenarios and simulations to train people for coordination and logistics handling under emergency situations. Related existing literature and theories about decision making, teamwork and situation awareness are studied and consulted to design new scenarios. Several scenarios were developed and initial experiments were conducted on these scenarios to check whether they meet intended behavior or not. Result of experiments proved success of scenario‟ design and these scenarios along their training goals, player and manager instructions are documented in report. It can be used to train and test team‟s ability for coordination and logistics aspects in emergency situations. Exhaustive testing of scenarios on large experiment base is left as future work.</p>
8

Coordination and Logistic Aspects in Computer Based Training for Emergency Situations

Nadeem, Hassam, Dastgeer, Usman January 2009 (has links)
This report presents research study conducted at Linkoping University on coordination and logistics training design in simulation based environment.This study is based on C3Fire simulation environment for designing scenarios and simulations to train people for coordination and logistics handling under emergency situations. Related existing literature and theories about decision making, teamwork and situation awareness are studied and consulted to design new scenarios. Several scenarios were developed and initial experiments were conducted on these scenarios to check whether they meet intended behavior or not. Result of experiments proved success of scenario‟ design and these scenarios along their training goals, player and manager instructions are documented in report. It can be used to train and test team‟s ability for coordination and logistics aspects in emergency situations. Exhaustive testing of scenarios on large experiment base is left as future work.
9

SIMOO : plataforma orientada a objetos para simulação discreta multi-paradigma / SIMOO: object oriented environment for multi-paradigm event discrete simulation

Copstein, Bernardo January 1997 (has links)
Analisando-se a literatura de simulação discreta pode-se observar que os autores, em geral, constroem seus modelos de simulação baseados em abordagens tradicionais e aceitas tais como orientação a eventos, orientação a mensagens, orientação a filas, etc. Mais recentemente encontram-se ambientes que afirmam utilizar o chamado paradigma de simulação orientado a objetos. No entanto não existe consenso na definição de tal paradigma e diferentes interpretações podem ser encontradas. Considerando que um modelo de simulação pertence a classe dos sistemas de software, nada mais natural do que aplicar conceitos de orientação a objetos em seu desenvolvimento. Deve ficar claro, entretanto, que existe uma grande diferença entre um paradigma de simulação, isto é, as idéias e recursos usados na construção de um modelo, e um paradigma de projeto e implementação aplicado ao desenvolvimento de sistemas de simulação. Linguagens orientadas a objetos podem ser aplicadas na implementação de sistemas de simulação que utilizam conceitos de modelagem distintos. Ainda que todos possam ser chamados de sistemas orientados a objetos, pode haver confusão quanto ao significado do termo simulação orientada a objetos. Este trabalho apresenta um esquema original de classificação para sistemas de simulação quanto a sua arquitetura de software onde são considerados aspectos tais como a maneira pela qual as entidades do modelo se comunicam e a forma pela qual se descrevem os eventos que alteram seu estado, entre outros. Conceitos fundamentais são identificados de maneira a definir um modelo de referencia onde diferentes paradigmas de simulação possam ser caracterizados e classificados. Especial atenção e dada ao relacionamento entre os paradigmas de simulação e a orientação a objetos, onde esta Ultima e vista como uma estratégia de projeto e implementação. Uma nova forma de caracterizar um paradigma de simulação e proposta. SIMOO e um "framework. ' para simulação discreta orientada a objetos que foi construído de maneira a poder validar os conceitos propostos. Composto por uma biblioteca de classes e de uma ferramenta de edição de modelos, a principal vantagem do use de SIMOO em relação a outras abordagens esta no fato de que SIMOO permite a seleção do paradigma mais adequado a descrição de cada entidade do modelo. Esta característica permite a criação de modelos que incorporam, simultaneamente, mais de um paradigma de simulação. A abstração básica da biblioteca de classes de SIMOO, a partir da qual são derivadas todas as entidades de um modelo, e o elemento autônomo. Este encapsula uma "thread" própria de execução e um sistema de comunicação por mensagens não tipadas que são a base de todos os paradigmas suportados por SIMOO. A ferramenta de edição de modelos de SIMOO e chamada de MET. MET utiliza um diagrama de classes hierárquico enriquecido com recursos adequados para a construção de modelos de simulação. Além do diagrama de classes, descreve-se também um diagrama de instâncias, onde as especificações genéricas do diagrama de classes são particularizadas. A partir da especificação dos diagramas e da descrição do comportamento das entidades, MET gera um modelo executável. Finalmente, SIMOO preocupa-se com a separação de domínios entre a descrição do modelo propriamente dito e os aspectos de visualização de resultados e interação com o usuário. Uma categoria especial de elementos autônomos chamados de monitores e provida para permitir essa separação. Além de apresentar o "framework" SIMOO em termos de especificação e implementação, este trabalho mostra aplicações através de situações exemplo e apresenta uma análise comparativa com outros ambientes descritos na literatura. / When one surveys the literature on discrete simulation. it will be noticed that, in general. authors build their simulation models usin g traditional approaches such as event-oriented. message-oriented, queue-oriented. etc. In more recent texts, frameworks can be found that allegedly use the so called object-oriented simulation paradigm. However, there is no generally accepted definition of such a paradigm. and various interpretations can be found. If we consider that a simulation system is an instance of the more general class of software systems, it is strai ghtforward to apply concepts of object orientation to develop simulation systems. Nonetheless. it is important to emphasize that there is a major difference between a simulation paradigm. i.e.. the principles and resources used to build the model, and a design and implementation paradi gm used to develop the simulation system. Object-oriented languages can be used to implement simulation systems that follow different paradigms. If we refer to all these systems as objectoriented systems, confusion about the exact meanin g of object-oriented simulation may occur. This work presents an original classification of simulation systems according to their software architectures, where different aspects are taken into account, such as the way the entities in the model communicate with each other, the way one describes events that modify the entities' state, and others. In this classification, we identify basic concepts that are used to define a reference model, with which different simulation paradigms may be characterized and classified. In particular, special attention to the relationship between simulation paradigms and object-orientation is given, the latter here being seen as a strategy to design and implement simulation systems. SIMOO is an object-oriented framework for discrete simulation. composed by a Class Library and a Model Editing Tool that has been built in order to validate the proposed concepts. The main advantage of SIMOO with respect to other frameworks is that it allows a selection of the most adequate paradigm to describe each entity in the model. As a consequence, we are able to create models that instantiate, simultaneously, more than one simulation paradigm. The basic element of the SIMOO class library, based on which the framework derives all the entities in the model, is the autonomous element. This autonomous element has its own execution thread and an untyped message-based communication system that constitute the basis of all the paradigms SIMOO supports. The SIMOO Model Editing Tool (MET) uses a hierarchical class diagram extended with resources needed to build simulation models. Along with the classe diagram, MET allows one to describe an instance diagram that details the more generic class diagram. From the diagrams and the description of the behavior of the entities, MET generates an executable model. The SIMOO framework also emphasizes the distinction between model description and aspects of visualization and user interaction. It provides a special category of autonomous elements, the monitors, that implements this separation. Besides presenting the formal specification and the implementation of the framework, in this work several examples of how to use the SIMOO are presented, along with a comparison with other existing frameworks.
10

Integration Paradigms for Ensemble-based Smart Cyber-Physical Systems / Integration Paradigms for Ensemble-based Smart Cyber-Physical Systems

Matěna, Vladimír January 2018 (has links)
Smart Cyber-Physical Systems (sCPS) are complex systems performing smart coordination that often require decentralized and network resilient operation. New development in the fields of the robotic systems, Industry 4.0 and autonomous vehicular system brings challenges that can be tackled with deployment of ensemble based sCPS, but require further refinement in terms of network resilience and data propagation. This thesis maps the use cases of the sCPS in the aforementioned domains, discusses requirements on the ensemble based architecture in terms of network properties, and proposes recommendations and technical means that help to design network aware ensemble based sCPS. The proposed solutions are evaluated by the means of target systems simulation using state of the art realistic network and vehicular simulators.

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