Dans cette thèse, nous nous intéressons à deux modèles de feux de forêts définis sur Z. On étudie le modèle des feux de forêts sur Z avec propagation non instantanée dans le chapitre 2. Dans ce modèle, chaque site a trois états possibles : vide, occupé ou en feu. Un site vide devient occupé avec taux 1. Sur chaque site, des allumettes tombent avec taux λ. Si le site est occupé, il brûle pendant un temps exponentiel de paramètre π avant de se propager à ses deux voisins. S’ils sont eux-mêmes occupés, ils brûlent, sinon le feu s’éteint. On étudie l’asymptotique des feux rares c’est à dire la limite du processus lorsque λ → 0 et π → ∞. On montre qu’il y a trois catégories possibles de limites d’échelles, selon le régime dans lequel λ tend vers 0 et π vers l’infini. On étudie formellement et brièvement dans le chapitre 3 le modèle des feux de forêts sur Z en environnement aléatoire. Dans ce modèle, chaque site n’a que deux états possibles : vide ou occupé. On se donne un paramètre λ > 0, une loi ν sur (0 ,∞) et une suite (κi)i∈Z de variables aléatoires indépendantes identiquement distribuées selon ν. Un site vide i devient occupé avec taux κi. Sur chaque site, des allumettes tombent avec taux λ et détruisent immédiatement la composante de sites occupés correspondante. On étudie l’asymptotique des feux rares. Sous une hypothèse raisonnable sur ν, on espère que le processus converge, avec une renormalisation correcte, vers un modèle limite. On s’attend à distinguer trois processus limites différents / The aim of this work is to study two differents forest-fire processes defined on Z. In Chapter 2, we study the so-called one dimensional forest-fire process with non instantaeous propagation. In this model, each site has three possible states: ’vacant’, ’occupied’ or ’burning’. Vacant sites become occupied at rate 1. At each site, ignition (by lightning) occurs at rate λ. When a site is ignited, a fire starts and propagates to neighbors at rate π. We study the asymptotic behavior of this process as λ → 0 and π → ∞. We show that there are three possible classes of scaling limits, according to the regime in which λ → 0 and π → ∞. In Chapter 3, we study formally and briefly the so-called one dimensional forest-fire processes in random media. Here, each site has only two possible states: ’vacant’ or occupied’. Consider a parameter λ > 0, a probability distribution ν on (0 ,∞) as well as (κi)i∈Z an i.i.d. sequence of random variables with law ν. A vacant site i becomes occupied at rate κi. At each site, ignition (by lightning) occurs at rate λ. When a site is ignited, the fire destroys the corresponding component of occupied sites. We study the asymptotic behavior of this process as λ → 0. Under some quite reasonable assumptions on the law ν, we hope that the process converges, with a correct normalization, to a limit forest fire model. We expect that there are three possible classes of scaling limits

Made available in DSpace on 2014-12-17T14:57:49Z (GMT). No. of bitstreams: 1 IvanMFL.pdf: 663615 bytes, checksum: a9a612a8d366a8eadb51a7b7c58984a5 (MD5) Previous issue date: 2009-02-20 / Due to advances in the manufacturing process of orthopedic prostheses, the need for better quality shape reading techniques (i.e. with less uncertainty) of the residual limb of amputees became a challenge. To overcome these problems means to be able in obtaining accurate geometry information of the limb and, consequently, better manufacturing processes of both transfemural and transtibial prosthetic sockets. The key point for this task is to customize these readings trying to be as faithful as possible to the real profile of each patient. Within this context, firstly two prototype versions (α and β) of a 3D mechanical scanner for reading residual limbs shape based on reverse engineering techniques were designed. Prototype β is an improved version of prototype α, despite remaining working in analogical mode. Both prototypes are capable of producing a CAD representation of the limb via appropriated graphical sheets and were conceived to work purely by mechanical means. The first results were encouraging as they were able to achieve a great decrease concerning the degree of uncertainty of measurements when compared to traditional methods that are very inaccurate and outdated. For instance, it's not unusual to see these archaic methods in action by making use of ordinary home kind measure-tapes for exploring the limb's shape. Although prototype β improved the readings, it still required someone to input the plotted points (i.e. those marked in disk shape graphical sheets) to an academic CAD software called OrtoCAD. This task is performed by manual typing which is time consuming and carries very limited reliability. Furthermore, the number of coordinates obtained from the purely mechanical system is limited to sub-divisions of the graphical sheet (it records a point every 10 degrees with a resolution of one millimeter). These drawbacks were overcome by designing the second release of prototype β in which it was developed an electronic variation of the reading table components now capable of performing an automatic reading (i.e. no human intervention in digital mode). An interface software (i.e. drive) was built to facilitate data transfer. Much better results were obtained meaning less degree of uncertainty (it records a point every 2 degrees with a resolution of 1/10 mm). Additionally, it was proposed an algorithm to convert the CAD geometry, used by OrtoCAD, to an appropriate format and enabling the use of rapid prototyping equipment aiming future automation of the manufacturing process of prosthetic sockets. / Devido aos avan?os no processo de fabrica??o de pr?teses ortop?dicas, a necessidade de uma melhor qualidade t?cnica na leitura da forma (i.e., com menos incertezas) da parte residual dos amputados tornou-se um desafio. Para superar esses problemas ? necess?rio ser capaz de obter informa??es precisas da geometria do membro e, consequentemente, melhorar os processos de fabrica??o de pr?teses e cartuchos transfemurais e transtibiais. O ponto-chave para esta tarefa ? personalizar essas leituras tentando ser o mais fiel poss?vel ao verdadeiro perfil de cada paciente. Dentro deste contexto, duas vers?es (α e β) de um prot?tipo de um scanner 3D mec?nico para ler forma residual de membros com base em t?cnicas de engenharia reversa foram concebidas. Prot?tipo β ? uma vers?o melhorada do prot?tipo α, apesar de ainda trabalhar em modo anal?gico. Ambos os prot?tipos s?o capazes de produzir uma representa??o CAD do membro atrav?s de apropriada planilha gr?fica e foram concebidos para funcionar exclusivamente atrav?s de meios mec?nicos. Os primeiros resultados foram encorajadores, uma vez que foram capazes de conseguir uma grande redu??o em rela??o ao grau de incerteza das medi??es quando comparadas com as dos m?todos tradicionais, que s?o muito imprecisas e desatualizadas. Por exemplo, n?o ? incomum ver estes m?todos arcaicos sendo usados utilizando fitas m?tricas caseiras para medir a forma da perna do paciente. Embora o prot?tipo β tenha melhorado as leituras, ainda ? necess?rio algu?m para introduzir os pontos plotados (i.e., aqueles marcados na planilha em formato de disco gr?fico) para um software acad?mico CAD chamado OrtoCAD. Esta tarefa ? realizada por digita??o manual, que ? morosa e tem confiabilidade limitada. Al?m disso, o n?mero de coordenadas obtidas a partir do sistema puramente mec?nico ? limitado ?s subdivis?es do disco gr?fico (ele grava um ponto a cada 10 graus com uma resolu??o de um mil?metro). Estes inconvenientes foram resolvidos na concep??o da segunda vers?o do prot?tipo β, na qual foi desenvolvida uma adapta??o eletr?nica, tornando-o capaz de realizar uma leitura autom?tica (i.e., sem interven??o humana no modo digital). Um software de interface (i.e., driver), foi desenvolvido para facilitar a transfer?ncia de dados. Resultados muito melhores foram obtidos significando menor grau de incerteza (ele registra um ponto a cada 2 graus com uma resolu??o de 1/10 mm). Al?m disso, foi proposto um algoritmo para converter a geometria CAD, utilizada pelo OrtoCAD, para um formato adequado e que permita a utiliza??o de equipamento de prototipagem r?pida destinado a uma futura automa??o do processo de fabrica??o dos cartuchos de pr?teses.

Made available in DSpace on 2014-06-11T19:27:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-11-04Bitstream added on 2014-06-13T19:47:49Z : No. of bitstreams: 1 piccolineto_d_me_rcla.pdf: 4118966 bytes, checksum: 4e646121f3b1e99bbb9d2465931eae5a (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Esta pesquisa visa compreender as relações em rede do setor metal-mecânico nos municípios de Araras e Piracicaba. Estas relações podem ocorrer na escala local, nacional e global, tanto entre as empresas e a sociedade, quanto na forma de aglomerações e seus mercados consumidores, fornecedores e concorrentes. Estas redes podem se configurar em formas associativas mais coesas, originando territórios específicos. Avaliar as conexões e densidades dessas redes em formas organizacionais mais complexas é um dos objetivos principais desta pesquisa, que tem como pano de fundo elementos das Teorias Institucionais e da Teoria dos Sistemas Gerais, com o auxílio da técnica de matrizes-grafo. / This research aims to understand the relationship networking metal-mechanic sector in the municipalities of Araras and Piracicaba. These relationships can occur at local, national and global levels, both between enterprises and society, and in the form of agglomerations and their consumers, suppliers and competitors. These networks can be configured in forms of association more cohesive, resulting in specific territories. Evaluate the density of connections and networks in more complex organizational forms is a major goal of this research, which has the background elements of the Institutional Theory and the Theory of General Systems, with the help of the technique of matrix-graph.

Submitted by RONILSON DE SOUZA SANTOS null (rssantos@ufpa.br) on 2017-09-11T22:31:18Z No. of bitstreams: 1 TESE REVISADA COMPLETA.pdf: 2934350 bytes, checksum: edd9fbae10de2c963217f91009661d87 (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-09-12T17:42:28Z (GMT) No. of bitstreams: 1 santos_rs_dr_bot.pdf: 2934350 bytes, checksum: edd9fbae10de2c963217f91009661d87 (MD5) / Made available in DSpace on 2017-09-12T17:42:29Z (GMT). No. of bitstreams: 1 santos_rs_dr_bot.pdf: 2934350 bytes, checksum: edd9fbae10de2c963217f91009661d87 (MD5) Previous issue date: 2017-07-10 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação Amazônia Paraense de Amparo à Pesquisa (FAPESPA) / A mandioca, Manihot esculenta Crantz, originaria da América do Sul, alimenta aproximadamente 500 milhões de pessoas em todo o mundo. No Brasil, os cultivos têm produtividade média de 14 t ha-1, mas em alguns casos, podendo chegar até 30 t ha-1, sendo a fécula o principal produto obtido, que vem sendo utililizada como matéria prima nas indústrias de alimento, fármacos e química. Entretanto, os plantios ainda são caracterizados por práticas rudimentares de cultivo, principalmente, nas ações que compõem a operação de colheita, que é predominantemente manual, pouco ergonômica e marcada pela intensa demanda de esforço físico, dificultando a contratação de mão-de-obra para realização desta operação. Sobretudo, nos plantios que destinam a produção para indústria. Portanto, o objetivo deste trabalho foi avaliar três sistemas de colheita de mandioca, com análises efetuadas a partir do desempenho operacional, custo demandado, análise energética e qualidade de colheita. Os tratamentos foram caracterizados da seguinte forma: Sistema de colheita manual (S1), composto de poda manual da porção aérea da planta, arranquio das raízes, separação das raízes da cepa e embarque em unidade de transporte; sistema de colheita semi mecanizada (S2), composto de poda mecanizada da porção aérea da planta, desagregação mecanizada do solo, arranquio manual das raízes, separação das raízes da cepa e embarque das mesmas em unidade de transporte e sistema de colheita mecanizada (S3), composto de poda mecanizada da porção aérea da planta, desagregação mecanizada do solo, recolhimento e embarque mecanizado das raízes em unidade móvel de transporte. Destacam-se como principais resultados a capacidade de campo operacional-CCo nas ações de arranquio manual do sistema S1 e embarque mecanizado do sistema S3, os quais obtiveram 0,62 t h-1 a 12,4 t h-1, respectivamente. O recolhimento mecanizado das raízes que usou uma máquina capaz de realizar, simultaneamente, três ações da operação de colheita, obteve CCo de 10,24 t h-1, podendo representar a redução da dependência que a cultura tem com a mão-de-obra manual. Exceto o embarque mecanizado, as demais ações obtiveram Eficiência Operacional- EfO acima de 70%. Os custos operacionais totais variaram de R$ 21,84 t-1 a R$ 40,01 t-1, sistemas S2 e S3, respectivamente, com destaque para o S2 que contabilizou o menor custo, constituindo-se como a melhor opção para colheita de mandioca. A demanda de energia nos sistemas avaliados foi de 2,35 MJ t-1, 62, 61 MJ t-1 e 79,44 MJ t-1, sistemas S1, S2 e S3, respectivamente, com esses dois últimos sistemas obtendo balanço e eficiência energética positivos, mas com alta dependência de energia fóssil. Na avaliação da qualidade da colheita, a soma das impurezas orgânica e mineral variaram de 1,44% a 4,29%. Os níveis de dano físico ao produto colhido variaram de 7,5% a 11,5% e os percentuais de raízes não colhidas variaram de 2,3% a 4,1%, sendo que estes resultados podem ser considerados satisfatórios, quando comparados a qualidade de colheita mecanizada de sistema já consolidados. / The Manihot esculenta Crantz, originally from South America, feeds about 500 million people worldwide. In Brazil, this crop has an average yield of 14 t ha-1, but in some cases, this yield can be to 30 t ha-1, starch is the main product obtained, which has been used as raw material for food, drus and chemical industries. However, fields crops are still characterized by rudimentary management practices, mainly in the actions that make up the harvest operation, which is predominantly manual, no ergonomic and characterized by the intense demand of physical effort, situation that became difficult to hire people to labor this kind of operation, mainly if this crop for industry production. Therefore, the objective this work was to evaluate three cassava harvest system, with analysis performed based at the operational performance, demanded cost, energy analysis and harvest quality. The treatments were characterized as follows: Manual harvest system (S1) manual aerial pruning plants, manual pulling roots, manual separation roots, manual heaps roots and manual boarding roots into mobile transport unit; Semi-mechanized harvest system (S2) mechanized aerial pruning plants, soil detachment manual aerial pruning plants, manual pulling roots, manual separation roots, manual heaps roots and manual boarding roots into mobile transport unit and Mechanized harvest system (S3) mechanized aerial pruning plants, soil detachment, mechanized picking and mechanized boarding roots into mobile transport unit. The main results were the operational field capacity-CCo, of manual pruning from S1 system that obtened 0.62 t h-1 and mechanized picking from S3 system, which obtained at 12.4 t h-1. The mechanized harvest roots using a harvester machine was able to make, simultaneously, three actions harvesting operation, obtained CCo of 10.24 t h -1, this result can represent the reduction of dependence that the crop has with availability people to work. Except for the mechanized boarding, the other actions obtained Operational Efficiency - EfO above 70%. Total operating costs ranged from R$ 21.84 t-1 to R$ 40.01 t-1, systems S2 and S3, respectively, with S2 accounting for the lowest cost, being the best option for cassava harvest. The energy demand in systems evaluated was 2.35 MJ t-1, 62.61 MJ t-1 and 79.44 MJ t-1, S1, S2 and S3 systems, respectively, with this latter two systems obtaining balance and positive energy efficiency, but highly dependent of fossil energy. About harvest quality, the quantity of the organic and mineral impurities added ranged from 1.44% to 4.29%. The physical levels damage percentage of harvested roots ranged from 7.5% to 11.5% and the percentage of unharvested roots ranged from 2.3% to 4.1%, and these results can be considered satisfactory when compared to mechanized harvest quality of the system already consolidated.

Orientador: Elson Luciano Silva Pires / Banca: Silvia Selingardi Sampaio / Banca: Marcos Aurelio Saquet / Resumo: Esta pesquisa visa compreender as relações em rede do setor metal-mecânico nos municípios de Araras e Piracicaba. Estas relações podem ocorrer na escala local, nacional e global, tanto entre as empresas e a sociedade, quanto na forma de aglomerações e seus mercados consumidores, fornecedores e concorrentes. Estas redes podem se configurar em formas associativas mais coesas, originando territórios específicos. Avaliar as conexões e densidades dessas redes em formas organizacionais mais complexas é um dos objetivos principais desta pesquisa, que tem como pano de fundo elementos das Teorias Institucionais e da Teoria dos Sistemas Gerais, com o auxílio da técnica de matrizes-grafo. / Abstract: This research aims to understand the relationship networking metal-mechanic sector in the municipalities of Araras and Piracicaba. These relationships can occur at local, national and global levels, both between enterprises and society, and in the form of agglomerations and their consumers, suppliers and competitors. These networks can be configured in forms of association more cohesive, resulting in specific territories. Evaluate the density of connections and networks in more complex organizational forms is a major goal of this research, which has the background elements of the Institutional Theory and the Theory of General Systems, with the help of the technique of matrix-graph. / Mestre

Cette thèse est une contribution à la modélisation du comportement d'une suspension de bulles dans un fluide non newtonien du type fluide à seuil. Elle comprend trois parties. La première partie est une étude bibliographique recensant les travaux théoriques et expérimentaux pour des bulles cisaillées dans un matériau newtonien. La seconde partie est consacrée à l'étude expérimentale de cisaillement simple d'une bulle suspendue dans un fluide à seuil. La dernière partie présente une approche par changement d'échelle du comportement macroscopique d'une suspension de bulles dans un fluide à seuil. Pour le travail expérimental, nous avons développé un premier prototype de dispositif permettant de cisailler d'une bulle suspendue dans un fluide à seuil. Pour cela, une bulle d'air est injectée au sein d'un grand volume de Carbopol cisaillé loin de la bulle par un dispositif à bandes parallèles. Une première série d'essais a permis de montrer l'efficacité du dispositif et d'obtenir quelques résultats sur la déformabilité d'une bulle cisaillée par un fluide à seuil. Pour le travail théorique, d'abord nous avons proposé des estimations du comportement de la suspension dans le cas des schémas dilué, Mori-Tanaka, autocohérent et motifs morphologiques. Ces modèles nous ont permis de trouver que dans le régime élastique le module élastique macroscopique de la suspension dépend du nombre capillaire Caelast défini comme le rapport entre le module de cisaillement du fluide porteur et la pression capillaire de la bulle. Ensuite en utilisant une méthode d'homogénéisation sécante modifiée (Suquet 1997), nous avons estimé des caractéristiques non linéaires globales de la suspension. Le modèle prédit que le seuil d'écoulement de la suspension est égal au seuil d'écoulement du fluide porteur quelle que soit la taille des bulles. La validation de ces modèles micromécanique a été réalisée par comparaison aux résultats expérimentaux obtenus au laboratoire (Ducloué 2014).Mots clés : suspension de bulles, fluide à seuil, rhéologie, nombre capillaire, approche par changement d'échelle / This thesis contributes to characterizing the behavior of a suspension of bubbles dispersed in a non-Newtonian fluid (yield stress fluid type).It consists of three parts. The first part is a literature review identifying the theoretical and experimental works for bubbles sheared in a Newtonian material. The second part is dedicated to the experimental study of the simple shear of a bubble suspended in a yield stress fluid. The last part consists in developing an upscaling approach to study the macroscopic behavior of a suspension of bubbles in a yield stress fluid. For experimental work, we developped a first prototype of device for the study of the shearing of a bubble in a yield stress fluid. For that purpose, an air bubble is injected in a big volume of Carbopol sheared far from the bubble by a system in two parallel bands. A fist series of tests allowed to show the efficiency of the device and to obtain some results on the deformability of a sheared bubble in a yield stress fluid. For theoretical work, first we proposed estimates of the behavior of the suspension in the case of diluted scheme, Mori-Tanaka, autocoherent and morphological patterns. These models have allowed us to find that in the elastic regime the macroscopic elastic modulus of the suspension depends on the capillary number Caelast defined as the ratio of the shear modulus of the fluid suspended over the capillary pressure of the bubble. Then using a modified secant homogenization method (Suquet 1997), we estimated the overall nonlinear properties of the suspension. The model predicts that the overall yield stress of the suspension is that of the suspending fluid regardless of the size of bubbles. The validation of these micromechanical models was achieved thanks to the experimental results obtained in the laboratory (Ducloué 2014).Keywords: bubbles suspensions, yield stress fluid, rheology, capillary number, upscaling approach

Les modèles numériques présents dans les salles de chirurgie requièrent simultanément une précision millimétrique, une vitesse de résolution importante, tout en prenant en compte la variabilité inter-patient. Dans l’étude proposée, nous développons un modèle numérique du foie, intégrant des lois de comportement hyper-élastiques ainsi que l’impact mécanique de la vascularisation. Une fois constitué, le modèle est traité par des outils mathématiques de réduction de modèles et d’apprentissage afin de fournir une réponse en temps réel. Pour cela, des données mécaniques sont extraites d’indentations numériques puis homogénéisées, pour construire un modèle numérique intégrant l’impact de la vascularisation. Une fois validé sur un échantillon réel les déformations simulées sont utilisées par une méthode d’apprentissage pour construire une réponse fonctionnelle. Une fois intégrée dans un outil chirurgical, ce dernier permet de fournir une réponse en temps réel des déformations du foie. / Numerical models used for surgical application require simultaneously a precision close to the millimeter, high speed resolution and to account for the patient variabilities. In the present study, we develop a numerical model of the liver, which relies on hyper-elastic mechanical behavior completed with the vascularization impact on the macroscopic level. Once completed and implemented, the model is treated with model reduction and learning tools in order to provide a real-time response. Mechanical properties are extracted from numerical indentations and homogeneised to build a model accounting for the impact of the vascularization. Once validated on a real sample, simulated deformations are used as input to a learning solution to build a functional solution. Finally, the function is integrated in a surgical tool, to provide a quick and precise representation of the liver deformations.

Le but du travail est de montrer la faisabilité du tissage de filament de très faible diamètre (de l'ordre de 10 à 25 -tm) et de matières différentes (cuivre, or, polyester...). Les essais du comportement mécanique (traction, fatigue) du micro filament de cuivre ont montré la possibilité du tissage de ce type du filament à cette échelle. A partir de ces résultats, il est possible d'entrevoir des solutions techniques de tissage pour réaliser des tissus à partir de ces filaments. Ce travail a permis donc de concevoir les différentes parties de la machine de micro tissage : système d'alimentation des fils de chame, système de formation de la foule, système d'insertion du fil de trame, système de mouvement du peigne, système d'appel et de stockage du tissu. Le système de formation de la foule de type Jacquard représente le cœur de la machine à tisser. Il lève un verrou technologique persistant depuis de très nombreuses années. Les résultats prometteurs des micros actionneurs fluidiques ont permis de montrer la faisabilité du micro tissage. Ils ont permis également de valider le procédé de la fabrication d'un bloc des plusieurs actionneurs capable de séparer les filaments de chaîne pour former la foule. Le logiciel de contrôle et de dessin conçu permet à la fois de réaliser des armures et de les compiler en format convenable pour pouvoir les transmettre à la carte de contrôle. Cette dernière permet de contrôler les différentes parties de la machine à tisser. / The aim of this work is to demonstrate the feasibility ofweaving filaments of very small diameter (about 10 to 25 -tm) made ofvarious materials (copper, gold, polyester, etc...). The possibility of weaving copper micro filaments at this scale has been proved via the fatigue and traction mechanical tests. According to these results, it was possible to foresee weaving technical solutions to produce fabrics from these micro filaments. This work has permitted the design of the different parts of the micro weaving machine: warp let-off system, warp shedding system, filling insertion system, beat-up system and take-up system. Warp shedding system of Jacquard type represents the heart of the weaving machine. It solved the complicated technical problem ofweaving materials that persists since many years. The positive results of micro fluidic actuators have demonstrated the feasibility of micro weaving. They have also validated the process of manufacturing a block of severa! actuators capable of separating the warp filament's to form the shed. The created software of control and design allows to make weaves and to compile them into a convenient format to be transmitted to the control card. This card controls the different parts of the weaving machine.