Os sistemas de manufatura há muito vêm sendo objeto de interesse por profissionais e pesquisadores devido à busca de melhores técnicas visando o aumento da produtividade bem como pelo aumento da competitividade empresarial ao longo dos anos. Dentre seus componentes, o sistema de movimentação de materiais merece atenção especial pois, apesar de não aumentar o valor do produto, é responsável por manter o fluxo de materiais entre máquinas, células de manufatura, centros de custos ou mesmo entre empresas, que é imprescindível para qualquer sistema produtivo. Neste contexto, o presente trabalho propõe uma metodologia para a modelagem de sistemas flexíveis de movimentação de materiais e partes em ambiente fabril, focando-se em sistemas cuja movimentação possa ser realizada por VATs (Veículos Autônomos de Transporte). Considerando-se o sistema de movimentação de materiais como sendo um sistema a eventos discretos (SEDs), pode-se empregar técnicas derivadas das Redes de Petri como o PFS (Production Flow Schema) e o E-MFG (Enhanced Mark Flow Graph) na modelagem de tais sistemas. Para tanto, foram introduzidos conceitos de orientação a objetos ao E-MFG de forma a ampliar sua capacidade de modelagem, possibilitando a migração de um paradigma de modelagem orientada a processos para um de modelagem híbrida orientada a processos e a objetos. Como estudo de caso, apresenta-se a modelagem de uma simplificação do sistema de movimentação de materiais da Mercedes Benz do Brasil, situada em São Bernardo do Campo, São Paulo, para a qual se aplica a metodologia proposta. / Manufacturing systems have been object of interest of many professionals and researchers through the years due to the search of better methods for raising goods productivity and managerial competitiveness. Among its components, the material movement system deserves special attention because even not increasing the product value, it is responsible for keeping the flow of materials between machines, manufacturing cells, cost centers and also between companies, which is indispensable for any productive system. In this context, this work proposes a methodology for modeling flexible systems for materials and parts movement in the industrial environment, focusing on systems whose movement can be performed by AGVs (Autonomous Guided Vehicles). Considering the materials movement system as a Discrete Event System (DES), techniques derived from Petri Nets as PFS (Production Flow Schema) and E-MFG (Enhanced Mark Flow Graph) can be used for modeling those systems. To this purpose, concepts of object orientation are introduced to E-MFG in order to increase its modeling capacity, allowing the migration from the process oriented modeling paradigm to an hybrid object and process oriented modeling. A simplification of the materials movement system of the plant of "Mercedes Benz do Brasil", which is located in São Bernado do Campo, São Paulo, was used as a study case to illustrate the methodology presented.

Os sistemas de manufatura há muito vêm sendo objeto de interesse por profissionais e pesquisadores devido à busca de melhores técnicas visando o aumento da produtividade bem como pelo aumento da competitividade empresarial ao longo dos anos. Dentre seus componentes, o sistema de movimentação de materiais merece atenção especial pois, apesar de não aumentar o valor do produto, é responsável por manter o fluxo de materiais entre máquinas, células de manufatura, centros de custos ou mesmo entre empresas, que é imprescindível para qualquer sistema produtivo. Neste contexto, o presente trabalho propõe uma metodologia para a modelagem de sistemas flexíveis de movimentação de materiais e partes em ambiente fabril, focando-se em sistemas cuja movimentação possa ser realizada por VATs (Veículos Autônomos de Transporte). Considerando-se o sistema de movimentação de materiais como sendo um sistema a eventos discretos (SEDs), pode-se empregar técnicas derivadas das Redes de Petri como o PFS (Production Flow Schema) e o E-MFG (Enhanced Mark Flow Graph) na modelagem de tais sistemas. Para tanto, foram introduzidos conceitos de orientação a objetos ao E-MFG de forma a ampliar sua capacidade de modelagem, possibilitando a migração de um paradigma de modelagem orientada a processos para um de modelagem híbrida orientada a processos e a objetos. Como estudo de caso, apresenta-se a modelagem de uma simplificação do sistema de movimentação de materiais da Mercedes Benz do Brasil, situada em São Bernardo do Campo, São Paulo, para a qual se aplica a metodologia proposta. / Manufacturing systems have been object of interest of many professionals and researchers through the years due to the search of better methods for raising goods productivity and managerial competitiveness. Among its components, the material movement system deserves special attention because even not increasing the product value, it is responsible for keeping the flow of materials between machines, manufacturing cells, cost centers and also between companies, which is indispensable for any productive system. In this context, this work proposes a methodology for modeling flexible systems for materials and parts movement in the industrial environment, focusing on systems whose movement can be performed by AGVs (Autonomous Guided Vehicles). Considering the materials movement system as a Discrete Event System (DES), techniques derived from Petri Nets as PFS (Production Flow Schema) and E-MFG (Enhanced Mark Flow Graph) can be used for modeling those systems. To this purpose, concepts of object orientation are introduced to E-MFG in order to increase its modeling capacity, allowing the migration from the process oriented modeling paradigm to an hybrid object and process oriented modeling. A simplification of the materials movement system of the plant of "Mercedes Benz do Brasil", which is located in São Bernado do Campo, São Paulo, was used as a study case to illustrate the methodology presented.

Ce projet se place dans le cadre du développement des nouvelles technologies de l'énergie respectueuses de l'environnement. Les piles à combustibles à oxydes solides (SOFC) permettent, pour les applications stationnaires, la génération de puissance de 1kW à 2MW avec un rendement électrique pouvant atteindre 70%. Elles fonctionnent à très hautes températures, typiquement entre 700-1000°C. La cellule d'une SOFC est constituée d'un électrolyte dense pris en sandwich entre deux électrodes poreuses (anode et cathode). Les électrodes poreuses, élaborées à partir de poudres céramiques, représentent un élément critique de l'assemblage. En effet, elles doivent être suffisamment poreuses pour optimiser à la fois la diffusion des gaz et les réactions électrochimiques. Cette nécessité est en contradiction avec l'exigence d'une bonne tenue mécanique. Cette contradiction doit pouvoir être résolue en proposant des microstructures d'électrodes poreuses hiérarchisées ou anisotropes. L'objectif de cette thèse est de montrer différentes voies possibles pour optimiser l'électrode en s'appuyant en particulier sur des simulations numériques et sur des caractérisations tomographiques. Les électrodes sont élaborées en utilisant deux protocoles différents conduisant à des porosités isotropes et anisotropes. Les échantillons anisotropes sont préparés en utilisant la méthode de moulage par congélation à partir de poudres YSZ/LSM, typiques de matériaux d'électrode. Cette méthode de fabrication conduit à une porosité hiérarchisée. La porosité totale est définie par le taux de chargement dans la barbotine initiale. La microporosité diminue avec la température de frittage et la taille des macropores est fonction de la vitesse de solidification. Les échantillons isotropes sont préparés en utilisant des agents porogènes avec des caractéristiques identiques aux échantillons anisotropes. Ces électrodes sont caractérisées par la technique d'Archimède pour déterminer les taux de porosités (macro et micro) et par microscopie à balayage pour connaître la taille des macroporosités. Des images tridimensionnelles des microstructures sont obtenues par FIB-SEM (Focused Ion Beam, 15µm³) et par nanotomographie-X (75µm³), avec des résolutions de 10nm et 75nm, respectivement. Le rendement énergétique d'une électrode dépend de différents paramètres : composition YSZ/LSM, taux de porosité, taille des particules, conductivités électronique/ionique et résistance électrochimique. Ces paramètres sont étudiés en utilisant des microstructures numériques associées à un réseau de résistance. Les simulations permettent de déterminer les facteurs qui contrôlent la conductivité effective. Ces microstructures numériques sont élaborées à l'échelle de la taille des particules en utilisant le code dp3D basé sur la méthode des éléments discrets (DEM) et développé au sein du laboratoire SIMaP. Nous montrons par exemple qu'en dessous d'une certaine épaisseur, la composition YSZ/LSM a très peu d'influence sur la conductivité effective. Une méthode a également été développée pour calculer cette conductivité effective à partir d'une image de FIB prenant en compte la résistance électrochimique aux points triples (gaz, YSZ, LSM). La tenue mécanique des différentes microstructures est testée en compression jusqu'à la rupture. En parallèle, des calculs sur image, couplés à la DEM sont effectués pour simuler les propriétés mécaniques. Nous comparons le comportement des microstructures homogènes (obtenues avec des agents porogènes) et celui des microstructures anisotropes. Les modules et les contraintes à rupture sont surestimés par les simulations. Qualitativement, les résultats expérimentaux et de simulation montrent des mécanismes de rupture cohérents entre eux. Par ailleurs, les modules et les contraintes à rupture sont différents entre les deux types d'échantillon (anisotrope et isotrope). Cette anisotropie peut être utilisée pour optimiser les propriétés mécaniques suivant une direction. / This project is involved in the development of new green power sources. Solid Oxide Fuel Cells (SOFCs) can achieve an output power of 1kW to 2MW and an energy conversion of up to 70%. Temperatures between 700 and 1000°C are required. A typical cell is made of an electrolyte sandwiched between two porous electrodes (anode and cathode). Porous electrodes are elaborated from ceramic powders and are critical components of the whole structure. These electrodes need to be porous enough to optimize gaz diffusion and electrochemical reactions. This requirement is antagonist to the need of a good mechanical strength. This conflict could be solved using hierarchical or anisotropic electrode microstructures. The aim of this thesis is to investigate possible ways to optimize an electrode. Numerical simulations and nanotomography characterizations are used for this purpose. Electrodes are elaborated using two different protocoles leading to anisotropic and isotropic porosities. Anisotropic samples are prepared by freeze-casting from a slurry of YSZ and LSM, which are typical materials for SOFCs. Freze-casting leads to a hierarchical porosity. The overall porosity is controlled by the loading of the slurry. The microporosity decreases with sintering temperature and the macropore size is function of the freezing rate. Isotropic samples are processed using pore formers. The size and the amount of pore formers are selected to match the characteristics of the anisotropic samples. These electrodes are characterized with Archimedes technique to determine the porosity, and with scanning electron microscope (SEM) to obtain the size of macropores. Three dimensional images of the microstructures are captured using focused ion beam (FIB-SEM tomography) technique (10nm} resolution) and using X-ray nanotomography (75nm} resolution). The overpotentials in an electrode depend on different parameters: composition of YSZ/LSM, porosity, particle sizes, electronic/ionic conductivities and electrochemical resistance. These parameters are studied on numerical microstructures coupled with a resistor network. These numerical microstructures have been generated at th scale of particles, using a numerical code based on the discrete element method (DEM). Simulations can be used to determine the limiting factor on the effective conductivity. For example, we show that the composition of YSZ/LSM in a sample matters little for electrodes below a certain thickness. A new method has also been developed to compute the effective conductivity from a FIB-SEM image taking into account the electrochemical resistance at the triple point boundaries between gaz, YSZ and LSM. The mechanical response of the elaborated microstructures are tested in compression up to the fracture. In parallel, DEM simulations are performed to simulate mechanical properties based on 3D images. The mechanical behaviours of homogeneous samples (with pore formers) and anisotropic samples are compared. The yield strength and stiffness are overestimated by simulations. Qualitatively, experimental results and simulations show consistent failure mecanisms. Moreover, the yield strength and stiffness are different in the two types of sample (anisotropic and isotropic). Such an anisotropy could be used to optimize mechanical properties in one direction.

This thesis is focused on microsimulation of city traffic, specifically a small city circuit in Brno. The thesis describes approaches for solving the problem of road network representation and presents basic methods and models needed for traffic simulation on the level of individual vehicles control as well as on the level of simulator control. In the case of more possible solutions to the given problem, the features and suitability of these solutions are compared. In the practical part of the thesis, the structure of the proposed simulator is presented with all the dependencies among individual submodels, along with the description of implementation details related to the individual parts.

This master thesis deals with the price prediction on financial markets. It describes automated trading systems based on technical analysis and discusses a soft computing approach to construction of such systems. Also, this thesis combines conventional trading strategies with the fuzzy logic. The practical part of this thesis contains also a framework for composing, simulation and analysis of the automated trading strategies. The simulator contained in this framework is implemented in the Java language and based on DEVS formalism. Because of this, there is a possibility to embed real-time components into the trading model. This work contains also a database of historical financial data and tools for their automatic actualization.

Submitted by Livia Mello (liviacmello@yahoo.com.br) on 2016-09-28T18:01:55Z No. of bitstreams: 1 DissGCM.pdf: 2068084 bytes, checksum: 4d89da9569508f8b5d13a8b899ad055a (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-04T19:00:31Z (GMT) No. of bitstreams: 1 DissGCM.pdf: 2068084 bytes, checksum: 4d89da9569508f8b5d13a8b899ad055a (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-04T19:00:38Z (GMT) No. of bitstreams: 1 DissGCM.pdf: 2068084 bytes, checksum: 4d89da9569508f8b5d13a8b899ad055a (MD5) / Made available in DSpace on 2016-10-04T19:00:49Z (GMT). No. of bitstreams: 1 DissGCM.pdf: 2068084 bytes, checksum: 4d89da9569508f8b5d13a8b899ad055a (MD5) Previous issue date: 2015-12-14 / Não recebi financiamento / The quest for increased productivity has become a mantra repeated ad nauseam in many companies immersed in a globalized market. In this context, many computational techniques have becoming more popular, gaining followers, aiding and refining the process of decision-making. Among the various techniques available, the discrete event simulation stands out, as it allows studying the behavior of systems, real or not, in various conditions, allowing hypotheses to be tested without physical and financial resources are used. In the case of the animal feed industry, this technique becomes a very important tool, especially in the short term planning which involves the management of the floor operations. The animal feed industry is part of the agribusiness chain, and as such, has its inputs internationally listed, commodities, thus effectively managing its installed capacity is a strategic advantage for differentiation before the market needs in terms of cost, time and quality. In this sense, the objective of this study was to develop a discrete simulation model to assist the decision-making process on increasing the rate of bagging an animal feed industry, located in the state of São Paulo. For this study it has been used the Arena® software, Rockwell Software, and as a method of research modeling and simulation, and the simulation model development stages followed the methodology proposed by Law and Kelton (2000) and Banks (2010). Data were always collected with the same operator at the same time. As a result of simulation of the proposed model was possible to analyze different scenarios, assessing the dynamics of the system and with the performance indicators the equipment utilization rate, the amount of products produced and the consumption of electricity and natural gas per ton of product produced. Whereas the use of discrete simulation in animal feed industry belonging to the process industry and with hybrid production process, could be used due to the approach proposed by Spieckmann and Stobbe (2012). / A busca pelo aumento de produtividade tornou-se um mantra repetido à exaustão em muitas empresas imersas em um mercado globalizado. Neste contexto, muitas técnicas computacionais vêm ganhando espaço, conquistando adeptos, auxiliando e refinando o processo de tomada de decisão. Dentre as várias técnicas disponíveis, a simulação discreta se destaca, pois permite estudar o comportamento de sistemas, reais ou não, sob diversas condições, possibilitando que hipóteses sejam testadas sem que recursos físicos e financeiros sejam utilizados. No caso da indústria de nutrição animal, essa técnica se torna uma ferramenta muito relevante, principalmente no planejamento de curto prazo que envolve a gestão das operações do chão de fábrica. A indústria de nutrição animal está inserida na cadeia do agronegócio, e como tal, tem seus insumos cotados internacionalmente, commodities, assim uma gestão eficaz de sua capacidade instalada representa uma vantagem estratégica de diferenciação perante as necessidades do mercado em relação a custo, prazo e qualidade. Neste sentido, o objetivo deste trabalho foi desenvolver um modelo de simulação discreta para auxiliar o processo de tomada de decisão sobre o aumento da taxa de ensaque de uma indústria de nutrição animal, localizada no interior do estado de São Paulo. Para a realização deste estudo foi utilizado o software Arena®, da Rockwell Softwares, e como método de pesquisa a modelagem e simulação, sendo que as etapas de desenvolvimento do modelo de simulação seguiram a metodologia proposta por Law e Kelton (2000) e Banks (2010). Os dados foram coletados sempre com os mesmos operadores no mesmo horário. Como resultado da simulação do modelo proposto foi possível analisar diferentes cenários, avaliando a dinâmica do sistema e tendo como indicadores de desempenho a taxa de utilização dos equipamentos, a quantidade de produtos produzidos e o consumo de energia elétrica e gás natural por tonelada de produto produzido. Sendo que a utilização da simulação discreta na indústria de nutrição animal, pertencente à indústria de processo e com processo produtivo híbrido, foi possível devido à abordagem utilizada, proposta por Spieckmann e Stobbe (2012).

This work aims to design process of integrated circuits on the transistor level, specially using evolutionary algorithm. For this purpose it is necessary to choose reasonable level of abstraction during simulation, which is used for evaluation candidate solutions by fitness function. This simulation has to be fast enough to evaluate thousands of candidate solutions within seconds. This work discusses already used techniques for transistor level circuit design and it chooses useful parts for new design of faster and more reliable automated design process, which would be able to design complex logic circuits. The thesis also discusses implementation of this system and used approach with regard to encountered problems in transistor-level circuit design and optimization by evolution.

This masters thesis describes simulation of network using Network Simulator. Model of network and description of simulation is extracted from the analysis of configuration files of active network devices, and translated by a parser. Concept and implementation of the parser is described here. Because IPv4 addressing is not supported in Network Simulator, it was added as a new module. The Network Simulator is also extended by filtering properties of packets using access control lists. Practical usage of the implemented modules is demonstrated on a simulation of real network.