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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

Controle Hierárquico da Equação da Onda

Santiago, Claudemir Rodrigues 22 July 2011 (has links)
Made available in DSpace on 2015-05-15T11:45:59Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 715500 bytes, checksum: d95f1a0101cba7f4f31b21e2b0da1bb3 (MD5) Previous issue date: 2011-07-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The present work has the distributed control v applied to the linear wave's equation. We seek to reach two objective, one of the kind Controllability and another the not system state distance to a state y2 (x; t) predefined. This is an problem of multicriteria optimization, and to solves him, introduce the notion Stackelberg's Optimal Control (classical in economy), in which we divide v into two, tell v1 and v2, and each one will act in the respective part from the Boundary 1;2 with a hierarchy between the same. This way, we take over that v1 is the control leader and v1 will be the follower. To leave of this terminogy, we use the idea of the hierarchical control, that is, admit that given a right v1, optimize the second goal concerning v2 and find a relation such that v2 = F (v1). So, the first goal became function of v1, belonging to the kind approximate controlability that will be proved through a density criterion and a Holmgren's uniqueness theorem. Finally, proved for controlability close, from unicidade of the solution, find Optimality system for the control leader. / O presente trabalho tem o controle distribuído v aplicado á fronteira da Equação da Onda Linear. Buscamos atingir dois objetivos: um do tipo controlabilidade, e outro o não distanciamento do estado do sistema a um estado y2 (x; t) predefinido. Esse é um problema de otimização multicritério, e para solucioná-lo, introduzimos a noção de controle ótimo de Stackelberg (clássico em economia), no qual dividimos v em dois, digamos v1 e v2; e cada um atuará na respectiva parte da fronteira -1; -2, com uma hierarquia entre os mesmos. Assim, assumimos que v1 é o controle líder e v2 será o seguidor. A partir dessa terminologia, usamos a ideia do controle hierárquico, isto é, admitimos que dado um certo v1, otimizamos o segundo objetivo com respeito a v2 e encontramos uma relação tal que v2 = F (v1). Então, o primeiro objetivo tornou-se função de v1; sendo do tipo controlabilidade aproximada que será provado através de um critério de densidade e do teorema de unicidade de Holmgren. Por último, provada a controlabilidade aproximada e a partir da unicidade da solução, encontramos o sistema de otimalidade para o controle líder.
2

Controle hierárquico para a equação do calor via estratégia Stackelberg-Nash

Albuquerque., Islanita Cecília Alcantara de 29 September 2011 (has links)
Made available in DSpace on 2015-05-15T11:46:05Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 674722 bytes, checksum: eb17d5816a0fce98d1def5be593711f1 (MD5) Previous issue date: 2011-09-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / We have as main issue in this work the Hierarchical Control, which consists in a leader-followers system. We studied in special the heat equation approximate controllability under Stackelberg-Nash’s strategy, which is directed in controlling every system from local controls choices with the minimum possible costs. / Temos como principal tema neste trabalho o Controle Hierárquico, que consiste em um sistema de líder e seguidores. Estudamos em especial a controlabilidade aproximada da equação do Calor sob a estratégia de Stackelberg-Nash, estratégia esta direcionada em controlar todo sistema a partir de escolhas de controles locais com o mínimo de custos possíveis.
3

Analyse mathématique et contrôle optimal pour les équations d’advection-diffusion : Application au problème de transfert de nutriments pour les plantes en agroécologie / Mathematical analysis and optimal control of advection-diffusion equations : Application to nutrient transfer for plant in agroecology

Louison, Loïc 02 October 2015 (has links)
Les terres agricoles ont été durablement contaminées à la fois par les pesticides mis à la disposition des agriculteurs pour lutter contre les charançons et autres insectes nuisibles, et par les engrais azotées pour augmenter la productivité chez les plantes.Des recherches récentes concernent des cultures alternatives écologiques utilisant les plantes de service qui fournissent les nutriments aux plantes principales. Ce travail de thèse s'inscrit dans cette perspective, d'un point de vue modélisation.L'accent est mis sur la résolution de problèmes de contrôle du phénomène d'absorption de nutriments, par les racines dans la rhizosphère (partie proche des racines), en considérant les deux cas de sols : sol sain et sol pollué.Ces phénomènes d'absorption sont modélisés par des systèmes d'advection-diffusion de type Nye-Tinker-Barber (NTB). La concentration de nutriments absorbée, solution du problème, est une fonction du temps et de l'espace.On étudie l'existence de solution du système NTB dans les deux cas où la fonction d'absorption de nutriments à la frontière (surface de la racine) appelée fonction de Michealis-Menten, est linéaire et/ou non linéaire, à l’aide des outils d’analyse fonctionnelle. On étudie ensuite les problèmes de contrôle optimal associés au système NTB, en considérant les deux cas linéaire et non linéaire, en application pour les deux cas d’absorption de nutriments en sol non pollué puis en sol pollué. Pour le premier cas, on utilise les techniques classiques de recherche d'un contrôle pour les systèmes distribués, tandis que, pour le second cas, on fait appel aux notions de contrôle sans regret et contrôle à moindres regrets de J.-L. Lions. Les contrôles obtenus pour les différents problèmes sont caractérisés chacun par un système d'optimalité (SO) cas sans pollution, et système d’optimalité singulier (SOS) dans le cas avec pollution.= / Agriculture soils were highly contaminated for a long time by pesticides which were widely used by producers to fight against weevils. Soils where also contaminated by the use of fertilizers to increase the plant development. An ecological alternative using service plants is encouraged following recent research. The aim of this work is to give a mathematical and a modelling point of view as we study the mecha- nisms of nutrient transfer to plants using the mathematical analysis and optimal control theories. The two cases of polluted and non-polluted soils are considered. The nutrient transfer and uptake processes are modeled by an advection-diffusion system derived from the Nye-Tinker-Barber (NTB) model. The absorbed nutrient concentration represented by the Michaelis-Mention function at the root surface of the principal plant, depends on time and space. We study the existence of a solution for the linear and nonlinear NTB systems, then we characterize the opti- mal control which corresponds to the added nutrients from the service plant. For the pollution case, we use the concept of low-regret and no-regret control of J.-L. Lions.

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