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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.
61

Um modelo de simulação baseado em agentes para análise de cadeias de suprimento

Ferreira, Luciano January 2009 (has links)
Uma cadeia de suprimentos é uma rede composta por fornecedores, plantas de manufatura, depósitos, centros de distribuição e varejistas através da qual matériasprimas são adquiridas, transformadas e entregue aos consumidores. A gestão de cadeias de suprimentos (do inglês, Supply Chain Management - SCM) envolve a tomada de decisão nos níveis estratégico, tático e operacional, cujo objetivo é otimizar o desempenho da cadeia . O desenvolvimento de modelos para a avaliação de cadeias de suprimento é uma boa alternativa para estudar a gestão da demanda por produtos, bem como para analisar a efetividade de políticas de gerenciamento. Sistemas multiagentes são apropriados para estudar cadeias de suprimento, pois as diferentes unidades de negócio envolvidas podem ser modeladas como agentes autônomos, assim como suas regras de gerenciamento. Além disso, a modelagem do fluxo de produtos e do fluxo de informações, tais como volume de pedidos e prazos de entrega de um elo da cadeia para outro é facilitada. A análise da literatura especializada da área demonstra que a maior parte dos estudos procura resolver problemas específicos e sem considerar agentes normativos interferindo no comportamento individual de cada ator da cadeia. Este trabalho procura contribuir com o estado da arte da área de gestão de cadeias de suprimento da seguinte forma: (1) propondo um modelo de simulação, composto por agentes genéricos que podem ser facilmente estendidos e utilizados e outros contextos de aplicação, e (2) propondo a utilização dos conceitos de agentes normativos no contexto de cadeias de suprimento. A união dessas áreas (SCM e sistemas multiagentes normativos) aumenta as possibilidades de modelagem de cadeias de suprimento, permitindo a inclusão de entidades externas que normalmente exercem influência na gestão, tais como órgãos do governo, agências reguladoras e instituições eletrônicas. A modelagem da cadeia do biodiesel é apresentada como estudo de caso; os principais resultados obtidos são apresentados e discutidos. / The supply chain is a network of suppliers, factories, warehouses, distribution centers, and retailers through which raw materials are acquired, transformed, and delivered to customers. Supply-chain management (SCM) is the strategic, tactical, and operational decision making that optimizes supply-chain performance. Modeling supply chain is a good way of studying order fulfillments processes and investigating the effectiveness of management policies. Multiagentes models are increasingly being used of this purpose. A multiagent model fits well with the task of simulation supply chain because the businesses involved can be modeled as agents, each with its own inventory rules. It is also easy to model the flow of products down the chain and the flow of information, such as order volumes and lead times, from one organization to another. The analysis of the relevant literature shows that most research works carried out in this area aim to resolve specific problems. Some methodologies and more generic solutions have been proposed, but without considering normative agents which may interfere in the behaviour of actors of the supply chain. This work aims to contribute with the state of the art in the SCM area as follows: (1) building a simulation model to the supply chain context, providing generic agents which may be easily extended and used in other application contexts, and (2) exploiting normative agents in the context of supply chain modeling. The integration of these areas (SCM and normative multi-agent systems) increases the possibilities of supply chain modeling, allowing the inclusion of external entities which normally influence management, such as governmental organizations, regulating agencies and electronic institutions, to give some examples. The modeling of the biodiesel supply chain is presented as a case study; the main results are presented and discussed.
62

Desenvolvimento de sistemas de automação da manufatura usando arquiteturas orientadas a serviço e sistemas multi-agentes

Peixoto, João Alvarez January 2012 (has links)
Os requisitos de manufatura industrial apontam uma necessidade de reconfiguração e reprogramação do fluxo de processo, a fim de atender modificações no produto com as mudanças dos requisitos de mercado. Estas mudanças implicam em alterações no processo de fabricação, o que, em muitos casos, significa alterar o leiaute, reprogramar controladores, modificar acoplamentos e interfaceamentos, etc. Os tamanhos dos lotes de produção estão ficando menores e a variedade de produtos em uma mesma linha tem aumentado. Isto torna o tempo de preparação dos dispositivos de manufatura fator crucial na formação do custo final. Dispositivos com mais autonomia, capazes de se autogerenciar e que permitam uma troca rápida de funcionalidades passam a serem desejados em um ambiente de manufatura, onde os sistemas convencionais com programação centralizada, sequência definida no controlador central e arranjo de funcionalidades fixas deixam a desejar. Orientação a serviços é um conceito que propõe a descentralização do controle e a disposição de componentes de forma a se agruparem virtualmente e formar novos dispositivos, com novas funcionalidades, otimizando investimento, recurso e tempo de produção. Nesta abordagem os equipamentos passam a se comportar como agentes de manufatura, em um universo de multi-agentes, que negociam entre si o processo requerido, propiciando o atendimento à variação de produto e dispondo de um número maior de funcionalidades, o que reduz o tempo de troca de processos. Um estudo de caso de um sistema orientado a serviços, sob uma plataforma multi-agentes, é proposto neste trabalho, buscando fornecer subsídios para a análise de desempenho e potencialidades deste conceito. / The industrial manufacturing requirements indicate a need for reconfiguration and reprogramming of process flow in order to meet changes in the product with the changing market requirements. These changes imply changes in the manufacturing process, which in many cases, means changing the layout, reprogram controllers, modify interfaces and couplings etc. The production lot sizes are getting smaller and the variety of products in the same line has increased. This makes the preparation time of manufacturing devices crucial factor in the formation of the final cost. Devices with more autonomy, able to manage themselves and allow a rapid exchange of features are to be desired in a manufacturing environment, where conventional systems with centralized scheduling, sequence defined in the central controller and array of features still fall short. Service orientation is a concept that proposes to decentralize the control and disposition of components in order to regroup virtually and form new devices with new features, optimizing investment, resource and production time. In this approach the devices start to act as agents of manufacturing, in a universe of multi-agents, who negotiate among themselves the process required, providing care for the product variation and having a greater number of features, which reduces the switching time processes. A case study of system-oriented services, under a multi-agent platform is proposed in this work, aiming to provide tools for performance analysis and potential of the concept.
63

Modélisation et simulation informatique de l'innovation en médecine : Conception d'un outil d'aide à l'évaluation médico-économique des centres de radiothérapie / Modeling and computer simulation of medical innovation : Design of a aid to medico-economic evaluation of radiotherapy centers tool

Shtiliyanova, Anastasiya 26 November 2012 (has links)
La thèse porte sur la conception d'un prototype logiciel ayant pour but l'évaluation de l'offre et de la demande pour les centres utilisant des traitements innovants en radiothérapie (hadronthérapie, tomothérapie, stéréotaxie, Cyberknife . . .). Le domaine applicatif visé est le domaine médical. L'étude menée porte également sur la modélisation du comportement du patient face à ces nouvelles technologies, sur leur mise en place et leur utilisation au sein des établissements de santé. Dans notre étude, nous modélisons des facteurs très importants tels que la qualité de vie du patient et sa prise en charge au niveau hospitalier. Nous nous intéressons au coût d'installation et d'entretien des nouvelles technologies. Nous comparons les nouvelles techniques utilisées en radiothérapie avec celles déjà existantes et bien évaluées. La comparaison est effectuée sur plusieurs critères, comprenant les critères médicaux et les critères financiers, dont le remboursement par la sécurité sociale enFrance. L'outil logiciel correspondant est construit en utilisant des techniques de modélisation multi-agents, en intégrant les techniques et le savoir-faire médicaux, ainsi que des modèles épidémiologiques pour caractériser les patients concernés et les thérapies correspondantes dans les centres de radiothérapie. Des méthodes économiques sont implémentées pour évaluer les coûts correspondants. / The main subject of the thesis is the modelling and the implementation of a software prototype for evaluating the supply and the demand for radiotherapy centers using innovative therapies (such as hadrontherapy, tomotherapy, stereotaxy, Cyberknife, . . .). The prototype should be used in the medical domain. The patient behaviour with respect to those new technologies is studied as well as their utilization in health institutions. The study takes into account important factors such as the quality of life of the patient and its treatment in a hospital. The costs of installation and maintainance are included in the tool. The new innovative radiotherapy techniques are compared with the existing ones. The comparison is based on medical and financial criteria, including refunding by the French public health insurance system. The software is based on multi-agent systems, and integrates medical knowledge as well as epidemiologic models for characterizing patients and relevant radio-therapies. Economical methods are also implemented for evaluating the associated costs.
64

Desenvolvimento de sistemas de automação da manufatura usando arquiteturas orientadas a serviço e sistemas multi-agentes

Peixoto, João Alvarez January 2012 (has links)
Os requisitos de manufatura industrial apontam uma necessidade de reconfiguração e reprogramação do fluxo de processo, a fim de atender modificações no produto com as mudanças dos requisitos de mercado. Estas mudanças implicam em alterações no processo de fabricação, o que, em muitos casos, significa alterar o leiaute, reprogramar controladores, modificar acoplamentos e interfaceamentos, etc. Os tamanhos dos lotes de produção estão ficando menores e a variedade de produtos em uma mesma linha tem aumentado. Isto torna o tempo de preparação dos dispositivos de manufatura fator crucial na formação do custo final. Dispositivos com mais autonomia, capazes de se autogerenciar e que permitam uma troca rápida de funcionalidades passam a serem desejados em um ambiente de manufatura, onde os sistemas convencionais com programação centralizada, sequência definida no controlador central e arranjo de funcionalidades fixas deixam a desejar. Orientação a serviços é um conceito que propõe a descentralização do controle e a disposição de componentes de forma a se agruparem virtualmente e formar novos dispositivos, com novas funcionalidades, otimizando investimento, recurso e tempo de produção. Nesta abordagem os equipamentos passam a se comportar como agentes de manufatura, em um universo de multi-agentes, que negociam entre si o processo requerido, propiciando o atendimento à variação de produto e dispondo de um número maior de funcionalidades, o que reduz o tempo de troca de processos. Um estudo de caso de um sistema orientado a serviços, sob uma plataforma multi-agentes, é proposto neste trabalho, buscando fornecer subsídios para a análise de desempenho e potencialidades deste conceito. / The industrial manufacturing requirements indicate a need for reconfiguration and reprogramming of process flow in order to meet changes in the product with the changing market requirements. These changes imply changes in the manufacturing process, which in many cases, means changing the layout, reprogram controllers, modify interfaces and couplings etc. The production lot sizes are getting smaller and the variety of products in the same line has increased. This makes the preparation time of manufacturing devices crucial factor in the formation of the final cost. Devices with more autonomy, able to manage themselves and allow a rapid exchange of features are to be desired in a manufacturing environment, where conventional systems with centralized scheduling, sequence defined in the central controller and array of features still fall short. Service orientation is a concept that proposes to decentralize the control and disposition of components in order to regroup virtually and form new devices with new features, optimizing investment, resource and production time. In this approach the devices start to act as agents of manufacturing, in a universe of multi-agents, who negotiate among themselves the process required, providing care for the product variation and having a greater number of features, which reduces the switching time processes. A case study of system-oriented services, under a multi-agent platform is proposed in this work, aiming to provide tools for performance analysis and potential of the concept.
65

Simulação de uso de solo urbano utilizando uma abordagem baseada em sistemas multiagentes reativos / Land use simulation based in Multi-Agents Reactive Systems

Bastos, André Dias January 2007 (has links)
O planejamento urbano é muito importante para garantir o desenvolvimento sustentável das cidades modernas. Para isso, muitos aspectos devem ser considerados, tais como o crescimento urbano das mesmas, uma vez que, o entendimento das dinâmicas desse fenômeno é um pré-requisito para modelar e prever tendências futuras de mudanças de uso do solo/cobertura da terra (LUCC) e seus impactos ecológicos. Como as cidades são sistemas complexos, que envolvem vários atores com diferentes padrões de comportamento, uma das mais promissoras classes de modelos urbanos designados para simular e analisar mudanças de uso do solo são as baseadas em Sistemas Multiagentes (SMA). Sendo assim, este trabalho descreve uma proposta de abordagem baseada em agentes reativos aplicados na tarefa de simulação de crescimento urbano para a cidade de Bauru/SP, utilizando dados geográficos, extraídos de imagens de satélite, da ocupação e utilização efetiva do uso do solo dessa cidade em um período de aproximadamente trinta e cinco anos, para calibrar e validar o simulador. / Urban planning is a very important issue to guarantee the sustainable development of modern cities. For this, many aspects must be considered such as the urban growth. Understanding the dynamics of this phenomenon is a prerequisite for modelling and forecasting future trends of urban land use/cover change (LUCC) and its ecological impacts. Cities being complex systems, which involve various actors with different patterns of behaviour, one of the most promising class of urban models designed to simulate and analyze LUCC are based in Multi-Agent System (MAS). Hence, this work describes a proposal based in reactive agents applied in the simulation of urban growth of the city of Bauru/SP, using geographic data, extracted from satellite images, of the occupation and land use in this city in a time span of approximately thirty five years, to calibrate and validate the simulator developed.
66

Um modelo de simulação baseado em agentes para análise de cadeias de suprimento

Ferreira, Luciano January 2009 (has links)
Uma cadeia de suprimentos é uma rede composta por fornecedores, plantas de manufatura, depósitos, centros de distribuição e varejistas através da qual matériasprimas são adquiridas, transformadas e entregue aos consumidores. A gestão de cadeias de suprimentos (do inglês, Supply Chain Management - SCM) envolve a tomada de decisão nos níveis estratégico, tático e operacional, cujo objetivo é otimizar o desempenho da cadeia . O desenvolvimento de modelos para a avaliação de cadeias de suprimento é uma boa alternativa para estudar a gestão da demanda por produtos, bem como para analisar a efetividade de políticas de gerenciamento. Sistemas multiagentes são apropriados para estudar cadeias de suprimento, pois as diferentes unidades de negócio envolvidas podem ser modeladas como agentes autônomos, assim como suas regras de gerenciamento. Além disso, a modelagem do fluxo de produtos e do fluxo de informações, tais como volume de pedidos e prazos de entrega de um elo da cadeia para outro é facilitada. A análise da literatura especializada da área demonstra que a maior parte dos estudos procura resolver problemas específicos e sem considerar agentes normativos interferindo no comportamento individual de cada ator da cadeia. Este trabalho procura contribuir com o estado da arte da área de gestão de cadeias de suprimento da seguinte forma: (1) propondo um modelo de simulação, composto por agentes genéricos que podem ser facilmente estendidos e utilizados e outros contextos de aplicação, e (2) propondo a utilização dos conceitos de agentes normativos no contexto de cadeias de suprimento. A união dessas áreas (SCM e sistemas multiagentes normativos) aumenta as possibilidades de modelagem de cadeias de suprimento, permitindo a inclusão de entidades externas que normalmente exercem influência na gestão, tais como órgãos do governo, agências reguladoras e instituições eletrônicas. A modelagem da cadeia do biodiesel é apresentada como estudo de caso; os principais resultados obtidos são apresentados e discutidos. / The supply chain is a network of suppliers, factories, warehouses, distribution centers, and retailers through which raw materials are acquired, transformed, and delivered to customers. Supply-chain management (SCM) is the strategic, tactical, and operational decision making that optimizes supply-chain performance. Modeling supply chain is a good way of studying order fulfillments processes and investigating the effectiveness of management policies. Multiagentes models are increasingly being used of this purpose. A multiagent model fits well with the task of simulation supply chain because the businesses involved can be modeled as agents, each with its own inventory rules. It is also easy to model the flow of products down the chain and the flow of information, such as order volumes and lead times, from one organization to another. The analysis of the relevant literature shows that most research works carried out in this area aim to resolve specific problems. Some methodologies and more generic solutions have been proposed, but without considering normative agents which may interfere in the behaviour of actors of the supply chain. This work aims to contribute with the state of the art in the SCM area as follows: (1) building a simulation model to the supply chain context, providing generic agents which may be easily extended and used in other application contexts, and (2) exploiting normative agents in the context of supply chain modeling. The integration of these areas (SCM and normative multi-agent systems) increases the possibilities of supply chain modeling, allowing the inclusion of external entities which normally influence management, such as governmental organizations, regulating agencies and electronic institutions, to give some examples. The modeling of the biodiesel supply chain is presented as a case study; the main results are presented and discussed.
67

A Study Of Travel Agent System in Mobile Devices Using Travel Agent System and Semantic Web Technologies

Japala, Pradeep January 2009 (has links)
The thesis work intends to provide the cost implementation method for the travel products from the travel agency to the mobile devices. Mobile devices are now capable of accessing the internet services as their considerable advancements are achieved in the wireless devices. The mobile devices are capable of searching through the web content for extracting the required data. But as the search engines face the problems due to their searching strategies such as keyword based search, semantic web has come into picture. This thesis work explains how semantic web technologies are integrated in the mobile devices for getting the desired products for optimal price. Semantic web is the suitable for the travel agent system as there is exchange of information. The data from the mobile devices is carried through the agents between the travel agency and the devices. This work intends to provide how the semantic web and the multi-agent systems are helpful for searching the desired products of the user (using mobile devices). The agents in the multi-agent system communicate with each other in the travel agent system through the ontologies which are written in the OWL ontology language
68

Using multi-agent system for code and data propagation

Lupa, Aleksander January 2008 (has links)
This work presents the concept of code and data propagation in a multi-agent system. First, the concepts of agent and multi-agent system are defined and examples are presented. Also arguments for using agent approach are given and potential benefits are listed. Afterwards the idea of code and data propagation is defined and explained. Then some examples of real solutions are given along with propagation algorithms, which depict the way of introducing the concept into real system solutions. Afterwards the code and data propagation in a multi-agent system is described, which is in many cases based on the object migration. Discussion about this concept ends with describing the types of agent migration and giving some examples of systems with agent migration. Then three multi-agent environments are described and one is chosen to be the basis of the implemented application. Second part of work starts with description of systems principal objective, which is the distributed calculating of prime numbers. At the beginning, agents of the system are presented, and then the main system processes are depicted in detail. All algorithms are shown in sequence diagrams, which point all asynchronisms in the system. Afterwards migration phase is described with all migration types and algorithms. The experiments are conducted in two environments: home and university. The main aim is to find optimal configurations for both environments. The conclusion from this work is that introducing code and data propagation to a multiagent system in a form of agent migration in a heterogeneous network could considerably decrease the execution time. Moreover based on the efficiency vector of computers participating in the experiment there is a possibility to set a task distribution, which is close to optimal, without searching for optimal configuration every time when running the experiment.
69

A Multi-Agent System for playing the board game Risk / Ett Multi-Agent System som spelar brädspelet Risk

Olsson, Fredrik January 2005 (has links)
Risk is a game in which traditional Artificial-Intelligence methods such as for example iterative deepening and Alpha-Beta pruning can not successfully be applied due to the size of the search space. Distributed problem solving in the form of a multi-agent system might be the solution. This needs to be tested before it is possible to tell if a multi-agent system will be successful at playing Risk or not. In this thesis the development of a multi-agent system that plays Risk is explained. The system places an agent in every country on the board and uses a central agent for organizing communication. An auction mechanism is used for negotiation. The experiments show that a multi-agent solution indeed is a prosperous approach when developing a computer based player for the board game Risk. / I brädspelet Risk är det svårt att använda traditionella Artificiell-Intelligens-metoder eftersom sökrymden är extremt stor. Lösningen till detta kan vara att använda distribuerad problemlösning i form av ett multi-agent system. Detta måste testas innan man kan säga om ett multi-agent system är framgångsrikt, eller ej, i att spela Risk. Denna uppsats går igenom utvecklingen av ett multi-agent system som spelar Risk. Systemet placerar en agent i varje land på brädet och använder en central agent för att organisera kommunikationen. En auktionsmekanism används vid förhandlingar. Experimenten visar att ett multi-agent system är en framgångsrik infallsvinkel vid utveckling av en datorbaserad spelare för brädspelet Risk.
70

A Multi-Agent System for playing the board game Risk / Ett Multi-Agent System som spelar brädspelet Risk

Olsson, Fredrik January 2005 (has links)
Risk is a game in which traditional Artificial-Intelligence methods such as for example iterative deepening and Alpha-Beta pruning can not successfully be applied due to the size of the search space. Distributed problem solving in the form of a multi-agent system might be the solution. This needs to be tested before it is possible to tell if a multi-agent system will be successful at playing Risk or not. In this thesis the development of a multi-agent system that plays Risk is explained. The system places an agent in every country on the board and uses a central agent for organizing communication. An auction mechanism is used for negotiation. The experiments show that a multi-agent solution indeed is a prosperous approach when developing a computer based player for the board game Risk. / I brädspelet Risk är det svårt att använda traditionella Artificiell-Intelligens-metoder eftersom sökrymden är extremt stor. Lösningen till detta kan vara att använda distribuerad problemlösning i form av ett multi-agent system. Detta måste testas innan man kan säga om ett multi-agent system är framgångsrikt, eller ej, i att spela Risk. Denna uppsats går igenom utvecklingen av ett multi-agent system som spelar Risk. Systemet placerar en agent i varje land på brädet och använder en central agent för att organisera kommunikationen. En auktionsmekanism används vid förhandlingar. Experimenten visar att ett multi-agent system är en framgångsrik infallsvinkel vid utveckling av en datorbaserad spelare för brädspelet Risk.

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