Le développement croissant de l’urbanisme et des activités anthropiques fait peser une pression de plus en plus importante sur les zones côtières, touchant particulièrement les régions méditerranéennes. Les processus liés au changement climatique et aux activités humaines impactent en profondeur les écosystèmes marins et tout particulièrement les systèmes planctoniques qui présentent une sensibilité accrue aux perturbations du milieu. Toutefois, les effets de ces processus agissant de concert à long terme sur la structure et le fonctionnement des écosystèmes côtiers sont encore mal compris. Ainsi, les séries temporelles planctoniques représentent des outils précieux pour la compréhension des processus impactant le milieu marin. Les séries temporelles du laboratoire EBMA-PROTEE de Toulon font partie des séries les plus anciennes de Méditerranée et présentent l’intérêt de combiner l’impact des processus naturels et anthropiques sur les communautés phyto- et zooplanctoniques. C’est dans ce contexte que ce travail a pour objectif de préciser le rôle de ces facteurs sur la dynamique et la composition phyto- et zooplanctonique en Méditerranée nord-occidentale (Toulon, France). Une première partie a ainsi consisté à évaluer le rôle des mélanges verticaux se produisant au sein du bassin Ligure, comme moteur de la dynamique printanière du plancton au sein de la Rade de Toulon. Cette étude a permis d’identifier des variations significatives du régime des précipitations associées à des modifications de la salinité au sein du site de la Grande Rade de Toulon (« LaB ») sur la période 2005-2013. Variations retrouvées également sur 2 autres sites côtiers du bassin Ligure (« SOFCOM » and « Point B »). Conformément à l’hypothèse énoncée, les années conditionnées par un automne et un hiver secs ont présenté en moyenne une production phytoplanctonique printanière supérieure au sein des 3 sites, comparées aux années les plus humides. Toutefois, la présence de différences entre les sites a souligné l’impact important de mécanismes locaux sur le conditionnement de la dynamique phytoplanctonique. L’impact des changements de régime des précipitations sur la composition micro-phytoplanctonique et méso-zooplanctonique a été étudié au cours d’une seconde partie. Les résultats ont suggéré un changement profond des communautés phytoplanctoniques lié à l’augmentation des précipitations, impactant également la structure des communautés zooplanctoniques. Ainsi, ces résultats semblent indiquer que les précipitations interviennent au sein de deux processus, impactant différemment les communautés planctoniques : d’une part, une absence de précipitations participerait à la mise en place de mélanges hivernaux et à la fertilisation des eaux de surfaces au sein de bassin Ligure profitant à la rade de Toulon; d’autre part, les changements dans la composition phytoplanctonique ont évoqué la mise en place d’un processus d’eutrophisation durant les périodes pluvieuses, alimenté par les apports des rivières locales. En parallèle de cet aspect temporel, le suivi de la Petite et Grande Rade de Toulon caractérisés par un degré différent de la pression anthropique a permis, au cours d’une troisième partie, de tester le potentiel des compartiments phyto- et zooplanctoniques en tant qu’indicateur de l’augmentation de la pression anthropique. Cette étude a identifié une sensibilité accrue de la composition du zooplancton par rapport au phytoplancton. Enfin, des indicateurs de pression anthropique des zones côtières, basés sur les familles de copépodes, ont été proposés. / The growing development of urbanism and anthropogenic activities is source of increasing environmental pressure on marine coastal area and especially the Mediterranean Sea. Both human activities and climate change deeply impact marine ecosystems and particularly planktonic systems, which were sensitive to environmental change. However, the combined effect of these two processes on coastal systems functioning and structure over time remains poorly understood. Therefore, planktonic time series provide powerful tools for investigating the impacts of these perturbations. The PROTEE-EBMA laboratory planktonic time series from Toulon (France) are among the oldest from the Mediterranean Sea and provide records of effects for both natural and anthropogenic pressures on planktonic communities. In the context of global change, the present work aim to determine the role of these factors on dynamic and composition of phyto- and zooplankton in NW Mediterranean (Toulon, France). The first part focused on the role of vertical mixing in the Ligurian Sea as inter annual variation driver of the spring plankton bloom in Toulon Bay. The results revealed significant shifts in precipitation regime associated with salinity change into the Large Bay (Toulon) over the period 2005-2013. Same changes were observed into 2 Ligurian basin sites (”SOFCOM” and “Point B”). According to previous hypothesis, spring blooms of phytoplankton conditioned by dry autumns and winters were on average more intense than those from wet conditions. However, differences among sites highlighted importance of local drivers affecting phytoplanktonic dynamics. The second part aimed to investigate impact of precipitation and salinity changes on plankton composition. Results showed a dramatic change in phytoplankton community composition triggering by increasing precipitations and consequently lower salinity and subsequently leading to zooplankton community shifts. In addition, these results suggested that precipitation involved in two specific processes, affecting in a different manner the plankton communities: firstly, low precipitation could contribute on the triggering of winter mixing and thus in surface water fertilization of the Ligurian Basin impacting the Toulon Bays. On the other hand, phytoplankton community shifts also suggested a developing eutrophication processes in Toulon Bay during important precipitation periods driven by increasing local river inputs. In the third part, impact of anthropogenic pressure on both phyto- and zooplankton communities was investigated based on monitoring of two neighboring coastal systems characterized by distinct levels of human activities. Zooplankton communities showed higher sensibility to anthropogenic activities than phytoplankton communities. Finally, indicators of anthropogenic pressure based on copepod families were proposed.

Le travail mené au cours de cette thèse s'est intéressé à l'étude de la propagation des sources d'incertitudes (données nucléaires, paramètres technologiques, biais de calcul) sur les paramètres intégraux, et à la mise au point d'une méthode d'optimisation multi-critères basée sur l'approche de représentativité et de transposition, permettant de réduire cette incertitude a priori sur une grandeur ciblée (keff , distribution de puissance,...) dès la phase de conception d'un nouveau programme expérimental. La première partie de cette thèse s'est intéressée aux schémas de calcul pour la détermination des profils de sensibilité des paramètres intégraux aux données nucléaires pour différentes échelles de modélisation (cellule, assemblage et cœur), et à leur optimisation multi-filière (REL et RNR). Un schéma de calcul simplifié, basé sur les théories des perturbations standard et généralisée, permet dès à présent la propagation de ces incertitudes sur un large type de grandeur intégrale. Ces travaux ont notamment permis de vérifier la bonne représentativité des réseaux UOX et MOX mis en œuvre dans l'expérience EPICURE par rapport aux REP actuels avec chargement mixte, et de mettre en évidence l'importance de certaines données nucléaires dans l'effet de bascule des nappes de puissance dans les grands cœurs de réacteurs. La seconde partie du travail s'est focalisée sur la mise en place d'outils et de méthodes d'aide à la conception des programmes expérimentaux dans les maquettes critiques. Ces méthodes sont basées sur une approche d'optimisation multi-paramétrée de la représentativité en utilisant simultanément différentes grandeurs d'intérêt. Enfin, une étude originale a été réalisée sur la prise en compte des corrélations entre informations intégrales dans le processus de transposition. La prise en compte de ces corrélations, couplée à la méthode de transposition multi-paramétrée permet l'optimisation de nouvelles configurations expérimentales, répondant au mieux aux besoins de qualification complémentaires des outils de calcul.

[pt] Esta tese teve como objetivo o estudo do problema de Desempenho H2 Robusto, com enfase para o caso de perturbações lineares não estruturadas nos fatores coprimos normalizados da função de transferência que representa uma determinada planta nominal. A primeira parte desta tese foi dedicada à determinação de um novo índice de Desempenho H2 Robusto pela utilização de limitantes superiores, levando em conta dois fatores: melhoria destes limitantes com relação aos limitantes propostos na literatura e viabilidade de sua implementação numérica. A parte seguinte da tese foi dedicada à determinação de elementos que influenciam no Desempenho H2 Robusto. Estes elementos serviram de base para a definição de problemas de controle multiobjetivos que, por sua vez, geraram uma classe de controladores sobre a qual foi otimizado o índice de Desempenho H2 Robusto proposto nesta tese. / [en] The objective of this thesis was the study of the Robust H2 Performance problem, with emphasis on the case of linear and unstructured perturbations on the normalized coprime factors of the transfer function that represents the nominal plant. The first was dedicated to the determination of a new Robust H2 Performance index, by the utilization of upper bounds, taking into accunt two factors: better upper bounds, with relation to upper bonds proposed in the literature, and numerical implementation viability. The second part was dedicated to the determination of elements that have influence in the Robust H2 Performance. These elements became a basis for the definition of multiobjetive control problems, that generate a class of controllers, over which the Robust H2 Performance index, proposed in the first part of this thesis, was optimizated.

Made available in DSpace on 2015-03-04T18:50:47Z (GMT). No. of bitstreams: 1 tese completa.pdf: 1208568 bytes, checksum: c0cd1bce0998cd8116d5ae8f7429ef23 (MD5) Previous issue date: 2006-12-04 / Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / In this work, performance analysis and control synthesis for good performance are studied for systems subject to non-parametric perturbations which satisfy a prescribed norm bound. First, the performance analysis problem is considered for a given controller that ensures robust stability in presence of such perturbations.. The performance index used is the so-called worst-case index. Due to the the character of the correspondent non-convex problem, convex optimization problems in function spaces are formulated whose solutions are upper bounds on the worst-case index. Next, it is shown that when the decision variables are confined to finite dimensional subspaces, these problems can be formulated in terms of linear optimization problems in euclidean spaces with constraints defined by linear matrix inequalities (LMI s). On the basis of the upper bounds obtained, procedures for controller synthesis can be formulated, which consist of a D-K iteration procedure for minimization problems with respect to multipliers and robust satabilizing controllers. Using the Youla parametrization of these controllers, for a given set of multipliers it is shown that when the Youla parameter is confined to finite dimensional subspace, the synthesis formulations are equivalent to linear optimization problems in euclidean spaces with constraints defined by LMIs. In both the cases (analysis and synthesis) heuristics to iterative modify the confining subspaces are suggested. An approach analogous to the one robust problems was applied to robust filtering problems leading to similar results. It is worth noting that in this case, due to the fact that only open-loop systems are involved, the correspondent synthesis procedures do not require D-K itearation.. / Neste trabalho são estudados problemas de controle correspondentes à análise de desempenho e síntese de controladores para bom desempenho no sentido da norma de sistemas sujeitos a perturbações não-paramétricas e limitadas na norma . Inicialmente é considerado o problema de análise de desempenho de um dado controlador que assegure a estabilidade de um sistema sujeito a estas perturbações. O índice de desempenho utilizado é o chamado pior-caso . Dada a dificuldade de resolução do correspondente problema não-convexo , são formulados problemas de otimização convexa em espaços de funções cujas soluções são limitantes superiores para o pior-caso . A seguir, mostra-se que quando as variáveis de decisão são confinadas a subespaços de dimensão finita, estes problemas podem ser formulados em termos de problemas de otimização linear em espaços euclidianos com restrições definidas por desigualdades matriciais lineares (LMI s). Com base nos limitantes obtidos, podem ser formulados procedimentos de síntese de controladores, que consistem essencialmente em procedimentos do tipo D-K iteration para problemas de minimização com respeito a multiplicadores e controladores robustamente estabilizantes. Utilizando a parametrização de Youla destes controladores, mostra-se que, para um dado conjunto de multiplicadores, quando o parâmetro de Youla é confinado a um subespaço de dimensão finita, as formulações para síntese também são equivalentes a problemas de otimização linear em espaços euclidianos, com restrições definidas por LMI s. Em ambos os casos (análise e síntese) são sugeridos heurísticas para a modificação iterativa dos subespaços aos quais as variáveis de decisão serão confinadas. A mesma metodologia utilizada para os problemas de controle robusto aqui considerados, pode ser aplicada a problemas de filtragem robusta. Neste caso, devido ao fato de se tratar de sistemas em malha aberta, não há necessidade de procedimentos do tipo D-K iteration . In this work, performance analysis and control synthesis for good performance are studied for systems subject to non-parametric perturbations which satisfy a prescribed norm bound. First, the performance analysis problem is considered for a given controller that ensures robust stability in presence of such perturbations.. The performance index used is the so-called worst-case index. Due to the the character of the correspondent non-convex problem, convex optimization problems in function spaces are formulated whose solutions are upper bounds on the worst-case index. Next, it is shown that when the decision variables are confined to finite dimensional subspaces, these problems can be formulated in terms of linear optimization problems in euclidean spaces with constraints defined by linear matrix inequalities (LMI s). On the basis of the upper bounds obtained, procedures for controller synthesis can be formulated, which consist of a D-K iteration procedure for minimization problems with respect to multipliers and robust satabilizing controllers. Using the Youla parametrization of these controllers, for a given set of multipliers it is shown that when the Youla parameter is confined to finite dimensional subspace, the synthesis formulations are equivalent to linear optimization problems in euclidean spaces with constraints defined by LMIs. In both the cases (analysis and synthesis) heuristics to iterative modify the confining subspaces are suggested. An approach analogous to the one robust problems was applied to robust filtering problems leading to similar results. It is worth noting that in this case, due to the fact that only open-loop systems are involved, the correspondent synthesis procedures do not require D-K itearation..

In this work we study rate of convergence of attractors for parabolic equations. We consider various types of problems where the diffusion coefficient has varied profiles: large diffusion, localized large diffusion and large diffusion except in the neighborhood of a point where it becomes small. In all cases we obtain a singular perturbation where a rate of convergence of attractors is obtained. / Neste trabalho estudamos taxa de convergência de atratores para equações parabólicas. Consideramos vários tipos de problemas onde o coeficiente de difusão apresenta perfís variados: difusão grande, difusão grande localizada e difusão grande exceto na vizinhança de um ponto onde ela torna-se pequena. Em todos os casos consideramos perturbações singulares e uma taxa de convergência para os atratores é obtida.

In this work we study rate of convergence of attractors for parabolic equations. We consider various types of problems where the diffusion coefficient has varied profiles: large diffusion, localized large diffusion and large diffusion except in the neighborhood of a point where it becomes small. In all cases we obtain a singular perturbation where a rate of convergence of attractors is obtained. / Neste trabalho estudamos taxa de convergência de atratores para equações parabólicas. Consideramos vários tipos de problemas onde o coeficiente de difusão apresenta perfís variados: difusão grande, difusão grande localizada e difusão grande exceto na vizinhança de um ponto onde ela torna-se pequena. Em todos os casos consideramos perturbações singulares e uma taxa de convergência para os atratores é obtida.

Neste trabalho são estudados problemas de controle correspondentes à análise de desempenho e síntese de controladores para bom desempenho no sentido da norma de sistemas sujeitos a perturbações não-paramétricas e limitadas na norma . Inicialmente é considerado o problema de análise de desempenho de um dado controlador que assegure a estabilidade de um sistema sujeito a estas perturbações. O índice de desempenho utilizado é o chamado pior-caso . Dada a dificuldade de resolução do correspondente problema não-convexo , são formulados problemas de otimização convexa em espaços de funções cujas soluções são limitantes superiores para o pior-caso . A seguir, mostra-se que quando as variáveis de decisão são confinadas a subespaços de dimensão finita, estes problemas podem ser formulados em termos de problemas de otimização linear em espaços euclidianos com restrições definidas por desigualdades matriciais lineares (LMIs). Com base nos limitantes obtidos, podem ser formulados procedimentos de síntese de controladores, que consistem essencialmente em procedimentos do tipo D-K iteration para problemas de minimização com respeito a multiplicadores e controladores robustamente estabilizantes. Utilizando a parametrização de Youla destes controladores, mostra-se que, para um dado conjunto de multiplicadores, quando o parâmetro de Youla é confinado a um subespaço de dimensão finita, as formulações para síntese também são equivalentes a problemas de otimização linear em espaços euclidianos, com restrições definidas por LMIs. Em ambos os casos (análise e síntese) são sugeridos heurísticas para a modificação iterativa dos subespaços aos quais as variáveis de decisão serão confinadas. A mesma metodologia utilizada para os problemas de controle robusto aqui considerados, pode ser aplicada a problemas de filtragem robusta. Neste caso, devido ao fato de se tratar de sistemas em malha aberta, não há necessidade de procedimentos do tipo D-K iteration. In this work, performance analysis and control synthesis for good performance are studied for systems subject to non-parametric perturbations which satisfy a prescribed norm bound. First, the performance analysis problem is considered for a given controller that ensures robust stability in presence of such perturbations.. The performance index used is the so-called worst-case index. Due to the the character of the correspondent non-convex problem, convex optimization problems in function spaces are formulated whose solutions are upper bounds on the worst-case index. Next, it is shown that when the decision variables are confined to finite dimensional subspaces, these problems can be formulated in terms of linear optimization problems in euclidean spaces with constraints defined by linear matrix inequalities (LMIs). On the basis of the upper bounds obtained, procedures for controller synthesis can be formulated, which consist of a D-K iteration procedure for minimization problems with respect to multipliers and robust satabilizing controllers. Using the Youla parametrization of these controllers, for a given set of multipliers it is shown that when the Youla parameter is confined to finite dimensional subspace, the synthesis formulations are equivalent to linear optimization problems in euclidean spaces with constraints defined by LMIs. In both the cases (analysis and synthesis) heuristics to iterative modify the confining subspaces are suggested. An approach analogous to the one robust problems was applied to robust filtering problems leading to similar results. It is worth noting that in this case, due to the fact that only open-loop systems are involved, the correspondent synthesis procedures do not require D-K itearation.. / In this work, performance analysis and control synthesis for good performance are studied for systems subject to non-parametric perturbations which satisfy a prescribed norm bound. First, the performance analysis problem is considered for a given controller that ensures robust stability in presence of such perturbations.. The performance index used is the so-called worst-case index. Due to the the character of the correspondent non-convex problem, convex optimization problems in function spaces are formulated whose solutions are upper bounds on the worst-case index. Next, it is shown that when the decision variables are confined to finite dimensional subspaces, these problems can be formulated in terms of linear optimization problems in euclidean spaces with constraints defined by linear matrix inequalities (LMIs). On the basis of the upper bounds obtained, procedures for controller synthesis can be formulated, which consist of a D-K iteration procedure for minimization problems with respect to multipliers and robust satabilizing controllers. Using the Youla parametrization of these controllers, for a given set of multipliers it is shown that when the Youla parameter is confined to finite dimensional subspace, the synthesis formulations are equivalent to linear optimization problems in euclidean spaces with constraints defined by LMIs. In both the cases (analysis and synthesis) heuristics to iterative modify the confining subspaces are suggested. An approach analogous to the one robust problems was applied to robust filtering problems leading to similar results. It is worth noting that in this case, due to the fact that only open-loop systems are involved, the correspondent synthesis procedures do not require D-K itearation..

In this study, hypnotic analgesia in obstetrics is explained in terms of ecosystemic thinking, as opposed to traditional conceptualisations of hypnosis. Five case studies were used. Each case is described in detail, as well as the therapeutic rationale behind each case, in order to present the reader with an understanding for the thinking behind the doing of ecosystemic hypnotherapy. The study utilises a new paradigm approach to research which is explained and is in keeping with ecosystemic epistemology. / Psychology / M.A. (Clinical Psychology)

Cette thése traite du contrôle de la formation et du confinement variant dans le temps pour les systèmes multi-agents linéaires invariants avec hétérogénéité en tenant compte des délais d’entrée / sortie constants / variables dans le temps et des perturbations adaptées / incompatibles sous topologie de communication dirigée et fixe. De nouveaux formats de formes de formation variables dans le temps pour des systèmes homogènes et hétérogènes sont proposés. Les contrôleurs, conçus sur la base de techniques prédictives et adaptatives avec une technique d’observation, sont entièrement distribués et peuvent être appliqués à des systèmes à grande échelle. L’application sur les systèmes robotisés multi hétérogènes linéarisés est vérifiée. / This thesis deals with the time-varying formation and containment control for linear time-invariant multi-agent systems with heterogeneity considering constant / time-varying input / output delays and matched / mismatched disturbances under directed and fixed communication topology. New formats of time-varying formation shapes for homogeneous and heterogeneous systems are proposed. The controllers, which are designed based on predictive and adaptive techniques with observer technique, are fully distributed and can be applied to large-scale systems. The application on linearized heterogeneous multi mobile robot systems is verified.

In this study, hypnotic analgesia in obstetrics is explained in terms of ecosystemic thinking, as opposed to traditional conceptualisations of hypnosis. Five case studies were used. Each case is described in detail, as well as the therapeutic rationale behind each case, in order to present the reader with an understanding for the thinking behind the doing of ecosystemic hypnotherapy. The study utilises a new paradigm approach to research which is explained and is in keeping with ecosystemic epistemology. / Psychology / M.A. (Clinical Psychology)