Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Ce travail est consacré à l’étude d’estimateurs d'erreur a posteriori de type flux équilibrés et résiduels pour la résolution des équations de Reissner-Mindlin par la méthode des éléments finis. Le mémoire débute par l'introduction du problème aux limites et de son analyse de convergence a priori par la méthode des éléments finis. Nous construisons alors pour une discrétisation conforme un estimateur a posteriori de type flux équilibrés fiable, efficace et robuste en l'épaisseur de la plaque t. Nous obtenons finalement une constante multiplicative égale à 1 pour la fiabilité. Des tests numériques illustrent nos résultats pour différents maillages. Puis nous abordons le cas d’une discrétisation non-conforme, où nous proposons un estimateur a posteriori de type résiduel, utilisant une régularisation de la solution discrète. Des tests numériques illustrent également nos résultats. La suite du travail reprend la discrétisation conforme en construisant un estimateur a posteriori défini à partir de la résolution de problèmes localisés sur les patchs de la triangulation, menant à un choix plus consistant avec le problème aux limites. Le dernier chapitre est consacré à l'estimation a posteriori pour le problème aux valeurs propres de Reissner-Mindlin. L’estimateur obtenu est fiable et efficace pour la norme de l'erreur entre les vecteurs propres, permettant également de majorer l’erreur commise entre les valeurs propres. Des tests numériques illustrent nos résultats. / This work is devoted to the study of equilibrated fluxes and residual a posteriori error estimators for the finite element resolution of the Reissner-Mindlin system. This report begins by the introduction of the boundary value problem and of its a priori convergence analysis in the finite element method context. Then, an equilibrated fluxes a posteriori estimator is built for a conform discretization, which is proven to be reliable, efficient and robust on the plate thickness t. We finally obtain a multiplicative constant equal to 1 for the reliability. Numerical tests illustrate our results on different meshes. Then, we address the non-conforming discretization case, where a residual a posteriori estimator is proposed using a regularisation of the discrete solution. Numerical tests also illustrate our results. Next we come back to the conform discretization by building an a posteriori estimator defined from localised problems resolution on stars, leading to a consistent choice with the boundary value problem. The last chapter is devoted to an a posteriori estimation for the Reissner-Mindlin eigenvalues problem. The obtained estimator is reliable and efficient for the error norm between the eigenvectors, also allowing to evaluate the error between the eigenvalues. Numerical tests illustrate our results.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Cette thèse porte sur l analyse et l'optimisation de l'exploitation de systèmes de production évoluant dans un environnement incertain. Cette incertitude relève en même temps de facteurs liés à la fiabilité et à la maintenabilité de ces systèmes, aux quantités à produire et à stocker, et aux rejets dus à la non-conformité des produits reliée à l état de dégradation des systèmes. De nouvelles stratégies conjointes de maintenance-production-qualité sont proposées. Ces stratégies établissent, selon chacune des situations considérées, les meilleurs compromis concernant simultanément deux ou trois variables de décision telles que¡: la taille des lots à produire, la taille des stocks tampons, la périodicité du contrôle de la qualité, le seuil de taux de non-conformité servant de déclencheur d actions de maintenance à entreprendre sur les systèmes considérés. Pour chacune de ces stratégies intégrées, des approches de modélisation analytique combinées dans certains cas à la simulation sont adoptées. Des algorithmes de calcul des valeurs optimales des variables de décision sont également développés pour chaque stratégie. Enfin, des analyses de sensibilité sont menées pour établir l influence de certains paramètres techniques et économiques sur les solutions optimales obtenues. / We treat in this thesis the integration problem between the various components of the industrial magnagement which are maintenance (preventive maintenance, corrective maintenance, etc...), production (quantities to produce, stockpile size, etc...) And quality (rejection rate, non-compliances, etc...). To develop such integrated models production-maintenance -Quality, two complementary approaches are adopted, the first is based on mathematical modelling and the second one uses simulation. As a first step, we propose to solve malthematically the problem od dimensioning the size to be produced for a production system that can randomly move to an out of control statue and produce non-conforming units. The system is subjected to an age preventive maintenance policy. Once the transistiion to the state out of control is detected , a restouration of the system is planned for L time units later. A mathematical model was developed to determine the quantity Q of economic production and the age T for preventive maintenance. In a second step, we have developed a joint policy of preventive maintenance and quality control for a production system that can generate conforming and nonconforming units. For the modelling of these strategies, we used two different approaches : the first uses only analytical tool and the second uses the analytical tools and simulation. Each of the strategies proposed is based on a predictive maintenance policy. According to the rate of nonconforming units generared by the machine, one decides on the modelling of these strategies, suppose thar after having undergonemaintenance actions ( preventive maintenance or revivsion), the systeme returned to its original condition (AS GOOD AS NEW), In another approach based on simulation, we propose to relax this assumption and assume that the system returned to its original state only after the overhaul actions. After having undergone the preventive maintenance actions, the systems is in a state between i its initial state just before the stop (between AS GOOD AS NEW and AS BAD AS OLD).

Orientador: Kamal A.R. Ismail / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Campinas / Made available in DSpace on 2018-07-15T09:00:08Z (GMT). No. of bitstreams: 1 Milanez_LuizFernando_D.pdf: 3020643 bytes, checksum: 35cd766c2d68256097760484d0cf0733 (MD5) Previous issue date: 1982 / Resumo: O objetivo deste trabalho é a análise teórica e experimental do processo de solidificação em geometria esférica, em termos da posição da interface no tempo, da velocidade de avanço da frente de fusão, do perfil de temperatura e da taxa de transferência de calor na superfície da esfera. Inicialmente foi feita uma revisão bibliográfica detalhada dos trabalhos existentes sobre solidificação em esferas. Este trabalho foi desenvolvido em duas etapas distintas: tratamento teórico e verificação experimental. Na parte teórica foi dedicada atenção especial ao método simplificado de London e Seban por fornecer uma solução fechada, e ao método numérico de Tao para geometrias circulares. Um método numérico que utiliza malhas móveis, originalmente desenvolvido por Murray e Landis para o plano, foi aplicado para a esfera. O método integral para a solução de problemas de mudança de fase foi analisado e aplicado à geometria esférica. A partir de uma solução exata para o processo de mudança de fase no plano foi considerado um fator de correção geométrico para á obtenção de uma solução aproximada bastante simples para a esfera. Na parte experimental, foi projetada e construída uma montagem para permitir a verificação experimental do processo de solidificação em esferas e a validade dos modelos teóricos desenvolvidos. / Abstract: The objective of the present study is to investigate theoretically and experimentally the solidification process in spherical geometry and its major parameters such as the instantaneous position of solid liquid interface, temperature profile and heat transfer rate. A detailed literature investigation on the matter was conducted. The study is divided into two main parts; theoretical and numerical investigation and experimental verification. In the theoretical part, London e Seban's simplified model and the numerical model due to Tao were analised, numerical model due to Murray e Landis and the integral method were applied to spherical geometry, and finally a corrected method. These models were analised and compared one to other. Experimental testing rig was designed, installed and instrumented. Extensive testing programme was done to verify the models, establish their validity and to obtain a good insight in the problem. / Doutorado / Doutor em Engenharia Mecânica

Ce mémoire est consacré à mes travaux sur la dynamique conforme dans les espaces métriques. Il est constitué de deux parties, la première concernant les groupes hyperboliques, et la seconde l'itération de revêtements ramifiés dans des espaces topologiques. Ces deux parties sont reliées par le dictionnaire de D. Sullivan. On a choisi d'orienter l'exposition en prenant la conjecture de J.W. Cannon comme fil d'Ariane.

Made available in DSpace on 2014-06-11T19:27:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-03-18Bitstream added on 2014-06-13T18:07:05Z : No. of bitstreams: 1 duran_f_me_rcla.pdf: 816337 bytes, checksum: 421602866b9c43011151d36014b6623e (MD5) / O objetivo deste trabalho é estudar Transformações de Möbius arbitrárias por meio de transformações mais simples. Um estudo detalhado de inversão geométrica é realizado com o objetivo de estudar a inversão complexa. Apresentamos o comportamento das Transformações de Möbius no in nito e as classi camos em elíptica, hiperbólica, loxodrômica e parabólica / The aim of this work is the study of arbitrary Möbius transformations by use of simpler ones. A detailed study of geometric inversions is done to well understand complex inversions. We present the behavior of Möbius transformations at in nity and classify them as elliptic, hyperbolic, loxodromic, and parabolic

Submitted by Marcos Samuel (msamjunior@gmail.com) on 2016-06-07T14:17:43Z No. of bitstreams: 1 DissertacaoDanilo3.pdf: 314088 bytes, checksum: 95c05bfb4a38feadfbb8cb46d411403a (MD5) / Approved for entry into archive by Alda Lima da Silva (sivalda@ufba.br) on 2016-06-13T16:48:10Z (GMT) No. of bitstreams: 1 DissertacaoDanilo3.pdf: 314088 bytes, checksum: 95c05bfb4a38feadfbb8cb46d411403a (MD5) / Made available in DSpace on 2016-06-13T16:48:10Z (GMT). No. of bitstreams: 1 DissertacaoDanilo3.pdf: 314088 bytes, checksum: 95c05bfb4a38feadfbb8cb46d411403a (MD5) / Neste trabalho, estudamos medidas definidas no bordo de uma árvore enraizada, associadas a um grupoíde de homeomorfismos parciais e uma função potencial. Por aplicação do método de Patterson, obtemos uma construção geral para essa tal medida conforme. Fizemos uma associação ao odômetro e obtemos os seguintes resultados: Se o odômetro for de distorção limitada, a medida é ergódica. Sob variações somáveis, a medida é equivalente à única probabilidade invariante. Alémdisso, indentificamos essa classe de medidas com a classe das medidas G introduzido por Brown e Dooley.

Orientador: Thiago de Melo / Banca: Valderlei Marcos do Nascimento / Banca: Márcio de Jesus Soares / Resumo: O objetivo deste trabalho é estudar Transformações de Möbius arbitrárias por meio de transformações mais simples. Um estudo detalhado de inversão geométrica é realizado com o objetivo de estudar a inversão complexa. Apresentamos o comportamento das Transformações de Möbius no in nito e as classi camos em elíptica, hiperbólica, loxodrômica e parabólica / Abstract: The aim of this work is the study of arbitrary Möbius transformations by use of simpler ones. A detailed study of geometric inversions is done to well understand complex inversions. We present the behavior of Möbius transformations at in nity and classify them as elliptic, hyperbolic, loxodromic, and parabolic / Mestre

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.