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Made available in DSpace on 2015-05-15T11:46:17Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2216718 bytes, checksum: 2b03ed1c154fa751c5c18afd31a144ad (MD5) Previous issue date: 2014-04-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This work addresses a class of Trudinger-Moser type inequalities in weighted Sobolev spaces in R2. As an application of these inequalities and by using variational methods, we establish sufficient conditions for the existence, multiplicity and nonexistence of solutions for some classes of nonlinear Schrödinger elliptic equations (and systems of equations) with unbounded, singular or decaying radial potentials and involving nonlinearities with exponential critical growth of Trudinger-Moser type. / Este trabalho aborda uma classe de desigualdades do tipo Trudinger-Moser em espaços de Sobolev com peso em R2. Como aplicação destas desigualdades e usando métodos variacionais, estabeleceremos condições suficientes para a existência, multiplicidade e não-existência de soluções para algumas classes de equações (e sistemas de equações) de Schrödinger elípticas não-lineares com potenciais radiais ilimitados, singulares na origem ou decaindo a zero no infinito e envolvendo não-linearidades com crescimento crítico exponencial do tipo Trudinger-Moser.

Ce travail est dédié à l’étude des inégalités de type Landau-Kolmogorov en normes L2. Les mesures utilisées sont celles d’Hermite, de Laguerre-Sonin et de Jacobi. Ces inégalités sont obtenues en utilisant une méthode variationnelle. Elles font intervenir la norme d’un polynômes p et celles de ces dérivées. Dans un premier temps, on s'intéresse aux inégalités en une variable réelle qui font intervenir un nombre quelconque de normes. Les constantes correspondantes sont prises dans le domaine où une certaine forme bilinéaire est définie positive. Ensuite, on généralise ces résultats aux polynômes à plusieurs variables réelles en utilisant le produit tensoriel dans L2 et en faisant intervenir au plus les dérivées partielles secondes. Pour les mesures d'Hermite et de Laguerre-Sonin, ces inégalités sont étendues à toutes les fonctions d'un espace de Sobolev. Pour la mesure de Jacobi on donne des inégalités uniquement pour les polynômes d'un degré fixé par rapport à chaque variable. / This thesis is devoted to Landau-Kolmogorov type inequalities in L2 norm. The measures which are used, are the Hermite, the Laguerre-Sonin and the Jacobi ones. These inequalities are obtained by using a variational method and the involved the square norms of a polynomial p and some of its derivatives. Initially, we focused on inequalities in one real variable that involve any number of norms. The corresponding constants are taken in the domain where a certain biblinear form is positive definite. Then we generalize these results to polynomials in several real variables using the tensor product in L2 and involving at most the second partial derivatives. For the Hermite and Laguerrre-Sonin cases, these inequalities are extended to all functions of a Sobolev space. For the Jacobi case inequalities are given only for polynomials of degree fixed with respect to each variable.

We study the optimal conditions on a homeomorphism f : Ω → Rn which guarantee that the composition u◦f is weakly differentiable and its weak derivative belongs to the some function space. We show that if f has finite distortion and q-distortion Kq = |Df|q /Jf is integrable enough, then the composition operator Tf (u) = u ◦ f maps functions from W1,q loc into space W1,p loc and the well-known chain rule holds. To prove it we characterize when the inverse mapping f−1 maps sets of measure zero onto sets of measure zero (satisfies the Luzin (N−1 ) con- dition). We also fully characterize conditions for Sobolev-Lorentz space WLn,q for arbitrary q and for Sobolev Orlicz space WLq log L for q ≥ n and α > 0 or 1 < q ≤ n and α < 0. We find a necessary condition on f for Sobolev rearrangement invariant function space WX close to WLq , i.e. X has q-scaling property. 1

Dans cette thèse, nous nous proposons d'étudier et de traiter conjointement plusieurs problèmes phares en traitement d'images incluant le recalage d'images qui vise à apparier deux images via une transformation, la segmentation d'images dont le but est de délimiter les contours des objets présents au sein d'une image, et la décomposition d'images intimement liée au débruitage, partitionnant une image en une version plus régulière de celle-ci et sa partie complémentaire oscillante appelée texture, par des approches variationnelles locales et non locales. Les relations étroites existant entre ces différents problèmes motivent l'introduction de modèles conjoints dans lesquels chaque tâche aide les autres, surmontant ainsi certaines difficultés inhérentes au problème isolé. Le premier modèle proposé aborde la problématique de recalage d'images guidé par des résultats intermédiaires de segmentation préservant la topologie, dans un cadre variationnel. Un second modèle de segmentation et de recalage conjoint est introduit, étudié théoriquement et numériquement puis mis à l'épreuve à travers plusieurs simulations numériques. Le dernier modèle présenté tente de répondre à un besoin précis du CEREMA (Centre d'Études et d'Expertise sur les Risques, l'Environnement, la Mobilité et l'Aménagement) à savoir la détection automatique de fissures sur des images d'enrobés bitumineux. De part la complexité des images à traiter, une méthode conjointe de décomposition et de segmentation de structures fines est mise en place, puis justifiée théoriquement et numériquement, et enfin validée sur les images fournies. / In this thesis, we study and jointly address several important image processing problems including registration that aims at aligning images through a deformation, image segmentation whose goal consists in finding the edges delineating the objects inside an image, and image decomposition closely related to image denoising, and attempting to partition an image into a smoother version of it named cartoon and its complementary oscillatory part called texture, with both local and nonlocal variational approaches. The first proposed model addresses the topology-preserving segmentation-guided registration problem in a variational framework. A second joint segmentation and registration model is introduced, theoretically and numerically studied, then tested on various numerical simulations. The last model presented in this work tries to answer a more specific need expressed by the CEREMA (Centre of analysis and expertise on risks, environment, mobility and planning), namely automatic crack recovery detection on bituminous surface images. Due to the image complexity, a joint fine structure decomposition and segmentation model is proposed to deal with this problem. It is then theoretically and numerically justified and validated on the provided images.

<p>Doktorska disertacija je posvećena raznim klasama uop&scaron;tenih stohastičkih procesa i njihovim primenama na re&scaron;avanje singularnih stohastičkih parcijalnih diferencijalnih jednačina. U osnovi, disertacija se može podeliti na dva dela. Prvi deo disertacije (Glava 2) je posvećen strukturnoj karakterizaciji uop&scaron;tenih stohastičkih procesa u vidu haos ekspanzije i integralne reprezentacije. Drugi deo disertacije (Glava 3) čini primena dobijenih rezultata na re&middot;savanje stohastičkog Dirihleovog problema u kojem se množenje modelira Vikovim proizvodom, a koefcijenti eliptičnog diferencijalnog operatora su Kolomboovi uop&scaron;teni stohastički procesi.</p> / <p>Subject of the dissertation are various classes of generalized<br />stochastic processes and their applications to solving singular stochastic<br />partial di&reg;erential equations. Basically, the dissertation can be divided into<br />two parts. The &macr;rst part (Chapter 2) is devoted to structural characteri-<br />zations of generalized random processes in terms of chaos expansions and<br />integral representations. The second part of the dissertation (Chapter 3)<br />involves applications of the obtained results to solving a stochastic Dirichlet<br />problem, where multiplication is modeled by the Wick product, and the<br />coe&plusmn;cients of the elliptic di&reg;erential operator are Colombeau generalized<br />random processes.</p>