Dissertations / Theses on the topic 'Normality conditions'

Le projet de cette thèse est double. Le premier concerne l’extension des résultats précédents sur les conditions nécessaires d’optimalité pour des problèmes avec contraintes d’état, dans le cadre du contrôle optimal ainsi que dans le cadre de calcul des variations. Le deuxième objectif consiste à travailler sur deux nouveaux aspects de recherche : dériver des résultats de viabilité pour une classe de systèmes de contrôle avec des contraintes d’état dans lesquels les conditions dites ‘standard inward pointing conditions’ sont violées; et établir les conditions nécessaires d’optimalité pour des problèmes de minimisation de coût moyen éventuellement perturbés par des paramètres inconnus.Dans la première partie, nous examinons les conditions nécessaires d’optimalité qui jouent un rôle important dans la recherche de candidats pour être des solutions optimales parmi toutes les solutions admissibles. Cependant, dans les problèmes d’optimisation dynamique avec contraintes d’état, certaines situations pathologiques pourraient survenir. Par exemple, il se peut que le multiplicateur associé à la fonction objective (à minimiser) disparaisse. Dans ce cas, la fonction objective à minimiser n’intervient pas dans les conditions nécessaires de premier ordre: il s’agit du cas dit anormal. Un phénomène pire, appelé le cas dégénéré montre que, dans certaines circonstances, l’ensemble des trajectoires admissibles coïncide avec l’ensemble des candidats minimiseurs. Par conséquent, les conditions nécessaires ne donnent aucune information sur les minimiseurs possibles.Pour surmonter ces difficultés, de nouvelles hypothèses supplémentaires doivent être imposées, appelées les qualifications de la contrainte. Nous étudions ces deux problèmes (normalité et non dégénérescence) pour des problèmes de contrôle optimal impliquant des contraintes dynamiques exprimées en termes d’inclusion différentielle, lorsque le minimiseur a son point de départ dans une région où la contrainte d’état est non lisse. Nous prouvons que sous une information supplémentaire impliquant principalement le cône tangent de Clarke, les conditions nécessaires sous la forme dite ‘Extended Euler-Lagrange condition’ sont satisfaites en forme normale et non dégénérée pour deux classes de problèmes de contrôle optimal avec contrainte d’état. Le résultat sur la normalité est également appliqué pour le problème de calcul des variations avec contrainte d’état.Dans la deuxième partie de la thèse, nous considérons d’abord une classe de systèmes de contrôle avec contrainte d’état pour lesquels les qualifications de la contrainte standard du ‘premier ordre’ ne sont pas satisfaites, mais une qualification de la contrainte d’ordre supérieure (ordre 2) est satisfaite.Nous proposons une nouvelle construction des trajectoires admissibles (dit un résultat de viabilité) et nous étudions des exemples (tels que l’intégrateur non holonomique de Brockett) fournissant en plus un résultat d’estimation non linéaire. L’autre sujet de la deuxième partie de la thèse concerne l’étude d’une classe de problèmes de contrôle optimal dans lesquels des incertitudes apparaissent dans les données en termes de paramètres inconnus. En tenant compte d’un critère de performance sous la forme de coût moyen, une question cruciale est clairement de pouvoir caractériser les contrôles optimaux indépendamment de l’action du paramètre inconnu: cela permet de trouver une sorte de ‘meilleur compromis’ parmi toutes les réalisations possibles du système de contrôle tant que le paramètre varie. Pour ce type de problèmes, nous obtenons des conditions nécessaires d’optimalité sous la forme du Principe du Maximum (éventuellement pour le cas non lisse)<br>The project of this thesis is twofold. The first concerns the extension of previous results on necessary optimality conditions for state constrained problems in optimal control and in calculus of variations. The second aim consists in working along two new research lines: derive viability results for a class of control systems with state constraints in which ‘standard inward pointing conditions’ are violated; and establish necessary optimality conditions for average cost minimization problems possibly perturbed by unknown parameters.In the first part, we examine necessary optimality conditions which play an important role in finding candidates to be optimal solutions among all admissible solutions. However, in dynamic optimization problems with state constraints, some pathological situations might arise. For instance, it might occur that the multiplier associated with the objective function (to minimize) vanishes. In this case, the objective function to minimize does not intervene in first order necessary conditions: this is referred to as the abnormal case. A worse phenomenon, called the degenerate case shows that in some circumstances the set of admissible trajectories coincides with the set of candidates to be minimizers. Therefore the necessary conditions give no information on the possible minimizers.To overcome these difficulties, new additional hypotheses have to be imposed, known as constraint qualifications. We investigate these two issues (normality and non-degeneracy) for optimal control problems involving state constraints and dynamics expressed as a differential inclusion, when the minimizer has its left end-point in a region where the state constraint set in nonsmooth. We prove that under an additional information involving mainly the Clarke tangent cone, necessary conditions in the form of the Extended Euler-Lagrange condition are derived in the normal and non-degenerate form for two different classes of state constrained optimal control problems. Application of the normality result is shown also for the calculus of variations problem subject to a state constraint.In the second part of the thesis, we consider first a class of state constrained control systems for which standard ‘first order’ constraint qualifications are not satisfied, but a higher (second) order constraint qualification is satisfied. We propose a new construction for feasible trajectories (a viability result) and we investigate examples (such as the Brockett nonholonomic integrator) providing in addition a non-linear stimate result. The other topic of the second part of the thesis concerns the study of a class of optimal control problems in which uncertainties appear in the data in terms of unknown parameters. Taking into consideration an average cost criterion, a crucial issue is clearly to be able to characterize optimal controls independently of the unknown parameter action: this allows to find a sort of ‘best compromise’ among all the possible realizations of the control system as the parameter varies. For this type of problems, we derive necessary optimality conditions in the form of Maximum Principle (possibly nonsmooth)

The availability of ART has transformed HIV infection from a terminal illness into a disease that is manageable. South Africa bears the greatest burden of the AIDS epidemic, having the highest proportion of adults and young people living with HIV in the world. Studies of the experience of living with HIV have largely been dominated by a medical approach which tends to ignore the subjective experience and meaning of living with HIV. This study uses constructivist grounded theory to explore the subjective experience of living with HIV for young people who live in KwaZulu-Natal, South Africa. Qualitative methods were used to collect data; these consisted of individual interviews and focus group discussions with young people living with HIV, carers of young people and community members. This study presents a multifaceted understanding of the experience for young people of living with HIV. Disclosure, young people‟s interpretation of the meaning of living with HIV and maintaining normality were core categories identified in the young people‟s narratives. Disclosure created a space for young people to negotiate the social and personal meaning of living with HIV. Maintaining normality was an active process whereby young people engaged themselves in tasks which they perceived to be helpful in managing HIV stigma, negative social interpretations associated with living with HIV and the uncertainty of living with HIV. „Normalisation‟ was used in this process, which refers to the combination of strategies that young people employed to survive and maintain a state of wellness; however, it was a negotiated process rather than an outcome, and young people were actively balancing their lives in the midst of uncertainty. Young people‟s active agency and resilience permeated their narratives and the study.

Orientador: Célia Marisa Rizzatti Barbosa<br>Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba<br>Made available in DSpace on 2018-08-23T17:37:19Z (GMT). No. of bitstreams: 1 Martins_AnaPaulaVarelaBrown_D.pdf: 3744881 bytes, checksum: a8970291a17e34c43b5d7149f77a114b (MD5) Previous issue date: 2013<br>Resumo: A disfunção temporomandibular pode afetar músculos mastigatórios, articulação temporomandibular (ATM) ou ambos; possui elevada prevalência nas mulheres e sintoma mais comum é a dor. Foi proposto determinar mínima concentração efetiva da piperina para ativar o Potencial Receptor Transiente Vanilóide da subfamília 1 (TRPV1) na região da ATM direita de ratas Wistar, nas condições: normalidade, inflamação crônica na ATM, estresse crônico e associação destas. Foram desenvolvidos 2 estudos experimentais, randomizados, duplo-cegos (protocolo nº 2633-1). No estudo I, 48 animais foram distribuídos aleatoriamente em seis grupos, e cada grupo recebeu 30 ?l na ATM de uma das soluções: solução padrão (10% de álcool etílico, 10% de Tween 80 e 80% de solução salina estéril) ou 1, 2, 3, 4 e 5 ?g de piperina diluída em 100 ml da solução padrão. No estudo II, 144 ratas foram aleatoriamente distribuídas em grupos: A - inflamação crônica na ATM direita induzida pelo Adjuvante Completo de Freund; B - estresse crônico provocado pelo modelo crônico de estresse; C - associação dessas condições. Esses grupos foram subdivididos (n = 8), e injetados na ATM 30 ?l das mesmas soluções descritas previamente. Nos estudos, as ratas, na fase diestro do ciclo hormonal, após injeção de uma das soluções, foram avaliadas quanto ao comportamento nociceptivo, que consistia em quantificar o número de vezes que as ratas levantaram a cabeça abruptamente e tempo dispendido, em segundos (s), para coçar a região orofacial. Cada levantar da cabeça seguiu padrão uniforme de 1 segundo de duração, assim, os comportamentos foram expressos em função do tempo, possibilitando somatória. Para comparação estatística, foi empregado análise da variância e teste de Tukey-Kramer (P< 0,05). No estudo I, existiu diferença significante para comportamento de coçar a região orofacial entre os grupos de 2 ?g e 5 ?g (100,37 ± 63,81 s; 100,0 ± 60,5 s, respectivamente) e o controle (33.37 ± 18,48 s), e somatória dos comportamentos entre 2?g (130,87 ± 257,88 s) e o controle (62.75 ± 14,81 s). No estudo II, no grupo A, houve diferenças estatísticas significativas para os comportamentos de levantar a cabeça no grupo de 5?g (69,5 ± 16,44 s) e o controle (41,13 ± 15,06 s); coçar a região orofacial entre 4?g (51,5 ± 28,73 s) e o controle (14,71 ± 7,54 s), e na somatória entre 4 e 5?g (105,37 ± 22,64 s; 115,50 ± 35,14 s, respectivamente) e o controle (52,86 ± 17,46 s). No grupo B, nos comportamentos de levantar a cabeça entre 4 ?g (85,87 ± 19,21 s) e o controle (49,87 ± 10,70 s); coçar a região orofacial entre 5 ?g (48,25 ± 27,25 s) e o controle (35,75 ± 12,69 s). No grupo C, não houve diferença significante nos subgrupos. Assim, 0,02 ?g/ml de piperina mostrou-se a concentração mínima eficiente para provocar estímulo nociceptivo na condição de normalidade; a solução de 0,04 ?g/ml de piperina, para os grupos de inflamação crônica articular e de estresse crônico e para o grupo de associação das condições não foi evidenciado diferença estatística significante<br>Abstract: Temporomandibular Dysfunction may affect the masticatory muscles, temporomandibular joint (TMJ) or both, has high prevalence in women and most common symptoms is pain. It was proposed to determine minimal effective concentration of piperine to activate the transient receptor potential vanilloid subfamily 1 (TRPV1) in the right TMJ in Wistar female rats under the conditions: normal, chronic inflammation in the TMJ, chronic stress and inflammation and stress combination. It was developed two randomized double-blind experimental studies (n. 2633-1). In study I, 48 animals were randomly divides into six groups, each group received 30 ?l into the TMJ one of this solutions: standard solution (80% sterile saline, 10% Tween 80 and 10% ethyl alcohol) or 1, 2, 3, 4 and 5 ?g of piperine diluted in 100 ml of standard solution. In study II, 144 rats were randomly divided into groups: A - chronic inflammation in the right TMJ induced by Freund's Complete Adjuvant; B - chronic stress caused by chronic stress model; C - association of these conditions. These groups were divided (n = 8), and it was injected into the TMJ 30 ?l of the same solutions as previously describe. In both studies, rats in diestrous phase of the hormonal cycle, after injection of the solution, were assessed for nociceptive behavior, which consisted in quantify how many times the rats flinched its head and the time spent, in seconds (s), to rub the orofacial region. Each head flinch followed uniform pattern of 1 second duration, and the behaviors were expressed as time function, allowing the sum. For statistical comparison, it was used variance analysis and Tukey-Kramer (P<0.05). In study I, there was a significant difference for rubbing orofacial region between groups of 2 ?g and 5 ?g (100,37 ± 63,81 s, 100 ± 60,5 s, respectively) and control (33,37 ± 18,48 s), and the sum of the behaviors between 2?g (130,87 ± 257,88 s) and control (62,75 ± 14,81 s). In study II, in group A, there were statistical differences for head flinch behavior between 5?g (69,5 ± 16,44 s) and control (41,13 ± 15,06 s) groups; for rubbing orofacial region between 4?g (51,5 ± 28,73 s) and control (14,71 ± 7,54 s), and for the sum, among 4 and 5?g (105,37 ± 22,64 s, 115,50 ± 35,14 s, respectively) and controls (52,86 ± 17,46 s). In group B, for head flinching behavior there was significant difference between 4 ?g (85,87 ± 19,21 s) and control (49,87 ± 10,7 s); rubbing orofacial region, between 5 ?g (48,25 ± 27,25 s) and control (3,.75 ± 12,69 s). In group C, there was no significant difference in the subgroups. Thus, 0,02 ?g/ml of piperine showed the lowest concentration effective to cause noxious stimulation in normal condition, the solution of 0,04 ?g/ml of piperine, for groups of chronic joint inflammation and chronic stress and for association conditions group there was not statistical significant difference<br>Doutorado<br>Protese Dental<br>Doutora em Clínica Odontológica

We present a theoretical approach to the statistical analysis of the dependence of the gap time length between consecutive recurrent events, on a set of explanatory random variables and in the presence of right censoring. The dependence is expressed through regression-like and overdispersion parameters, estimated via estimating functions and equations. The mean and variance of the length of each gap time, conditioned on the observed history of prior events and other covariates, are known functions of parameters and covariates, and are part of the estimating functions. Under certain conditions on censoring, we construct normalized estimating functions that are asymptotically unbiased and contain only observed data. We then use modern mathematical techniques to prove the existence, consistency and asymptotic normality of a sequence of estimators of the parameters. Simulations support our theoretical results.