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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.
11

L’informité du traumatisme : plaidoyer pour une clinique et une topique dynamiques du traumatisme sexuel / Traumatic informity : plea for a dynamic clinical examination and topique of the sexual trauma

Calamote, Éric Pierre 28 June 2011 (has links)
Cette thèse s’attache à dégager les effets spécifiques des expériences traumatiques de nature sexuelle, et plus largement à modéliser le déploiement de tout traumatisme. L’informité traumatique y est particulièrement mise en évidence dans la façon dont l’expérience est atteinte au-delà de son contenu dans sa substance, ses contours et sa forme. Devant cette clinique de l’extrême où le patient se débat dans une économie le plus souvent paradoxale, le clinicien doit faire face à l’enchevêtrement des scènes traumatiques de l’histoire de son patient, d’un sujet n’abandonnant jamais véritablement le projet de configurer son expérience et de la situer topiquement. Pour rendre compte à la fois des effets du traumatisme et de son appel à former l’expérience, il convient de penser une topique au sein de laquelle peuvent se jouer et l’errance des éléments psychiques et la façon dont ils sont attractés pour arriver à configurer l’expérience, la symboliser. Cette topique est représentable par un cylindre développable en rubans de Möbius, cylindre contenant l’identité du sujet et dans lequel des zones de plis figurent les points où la matière psychique se forme et se spatialise. Ce cylindre où se joue l’expérience traumatique organisée en couple d’opposés, où se lisent également les efforts du sujet pour la circonscrire, n’est pensable que dans un modèle intersubjectif. Dans cette optique, et parce que l’économie traumatique impose plus que d’autres une réflexion sur le dispositif de soins et l’implication du thérapeute, on saisit mieux l’intérêt d’une double écoute (par deux psychologues cliniciens). Une part importante de ce travail de recherche concerne l’étude de la congruence de cette « copensée » avec la nouvelle modélisation du traumatisme. Ce travail de recherche laisse une large place à la clinique par l’exposé de longues vignettes retraçant le récit d’expériences traumatiques de patients, en replaçant ce déploiement (parfois sur plus de dix ans) dans l’épaisseur des séances, des échanges et des interactions entre les deux psychologues et leur patient. / The present thesis focuses on finding out the specific effects of a sexually traumatic experience and more generally on modelling the broadening of any trauma. It especially discusses the notion of traumatic informity by which an experience is impacted not simply in terms of its content, but also in terms of its essence, outline, and shape. Faced with these extreme clinical situations where the patient struggles in a most often paradoxical situation, the clinician must deal with the muddle of traumatic scenes characterizing his or her patient’s background, when the latter never completely gives up configurating his or her experience and topically situating it. In order to unearth the effects of the trauma as well as its ability to shape the experience, it is necessary to imagine a topique at the core of which the wandering psychic elements as the way they are attracted to each other - in such a way as to configurate and symbolize the experience - are at stake. This topique can be represented as a cylinder which can be unfolded into Möbius strips, and it contains the patient’s identity. The creases symbolize the places where psychic matter takes shape and broadens out. This cylinder, where the traumatic experience is at stake in opposed pairs and where the patient’s efforts to define it can be read, can only be envisioned as part of an intersubjective model. In this perspective, because traumatic economies necessitate pondering on health care measures and on the therapist’s level of engagement, it is easier for one to see how much more valuable a consultation with two clinical psychologists is. A significant part of this research work involves the study of the congruity of this “co-thought” with the new way of modelling a trauma. This research work leaves much room for clinical practice through long accounts retracing the patients’ history of traumatic experiences, as the two psychologists resituate the patient’s trauma’s broadening (sometimes over the course of ten years) during the intensity of the sessions, exchanges, and interactions.
12

Nanoestruturas de grafeno e o problema do confinamento de partículas de Dirac na descrição do contínuo

Souza, José Fernando Oliveira de 08 August 2014 (has links)
Submitted by Maike Costa (maiksebas@gmail.com) on 2016-03-15T13:04:40Z No. of bitstreams: 1 arquivototal.pdf: 6077553 bytes, checksum: 3cad3094833d2fdc458897bedccb4917 (MD5) / Made available in DSpace on 2016-03-15T13:04:40Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 6077553 bytes, checksum: 3cad3094833d2fdc458897bedccb4917 (MD5) Previous issue date: 2014-08-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this work, we investigate in parallel physical and mathematical aspects inherent to the problem of confinement of massless Dirac fermions in graphene nanostructures. In a low energy approach, we propose models to describe confining systems in graphene and study how the choice of boundary conditions of the problem - or, equivalently, of domains of the Dirac operator - affects the physical properties of such systems. In this scenario, we concentrate essentially on the study of the physical behavior of graphene nanorings and nanoribbons in response to aspects such as topology, edge and interface geometry and interactions with external fields. At the same time, a rigorous investigation concerning formal aspects of the problem and the way that they manifest themselves physically is also performed. In light of the theory of linear operators on Hilbert spaces, we analyze the role played by the notion of self-adjointness in the problem and establish sets of boundary conditions physically acceptable in graphene, which mathematically corresponds to the definition of self-adjoint extensions of the Dirac Hamiltonian from the continuum description. Sets proposed in the treatment of some studied configurations are approached in this context. In addition, we present a particular study in which we examine the influence of topological defects on the physics of massive fermions in graphene in the presence of Coulomb and uniform magnetic fields. / Neste trabalho, investigamos paralelamente os aspectos físicos e matemáticos inerentes ao problema do confinamento de férmions de Dirac sem massa em nanoestruturas de grafeno. Em uma abordagem no limite de baixas energias, propomos modelos para descrever sistemas confinantes no âmbito da física do grafeno e estudamos de que modo a escolha das condições de contorno do problema - ou, equivalentemente, dos domínios do operador de Dirac - exercem influência sobre as propriedades físicas de tais sistemas. Neste cenário, concentramo-nos essencialmente no estudo do comportamento físico de nanoanéis e nanofitas de grafeno em resposta a aspectos como topologia, geometria de borda e interface e interações com campos externos. Ao mesmo tempo, também é realizada uma rigorosa investigação acerca dos aspectos formais do problema e do modo como eles se refletem fisicamente. À luz da teoria dos operadores lineares em espaços de Hilbert, analisamos o papel desempenhado pela noção de self-adjointness na modelagem do problema e estabelecemos conjuntos de condições de contorno fisicamente aceitáveis relativamente ao grafeno, o que corresponde matematicamente à definição de extensões auto-adjuntas do Hamiltoniano de Dirac da descrição do contínuo. Conjuntos propostos no tratamento de algumas das configurações estudadas são abordados neste contexto. Além disso, apresentamos um estudo à parte em que examinamos a influência de defeitos topológicos na física de férmions com massa no grafeno na presença de interações de Coulomb e de campos magnéticos uniformes.
13

Anéis quânticos em superfícies não-orientáveis

Souza, José Fernando Oliveira de 22 December 2011 (has links)
Made available in DSpace on 2015-05-14T12:13:59Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 798447 bytes, checksum: d94f874d062caea280c4ce462ab3837a (MD5) Previous issue date: 2011-12-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this work, we explore the link between geometry and physical properties in 2D quantum rings. With focus on the non-orientable mesoscopic structures, we solve the quantum Möbius strip problem, a quantum ring whose lockdown surface is a Möbius strip, and investigate how the physical properties of those structures answer to the geometric variation of this particular configuration. More precisely, we investigate how the adoption of boundary conditions associated to this specific geometric configuration, in particular, can change the general properties of the 2D quantum rings. In addition, we still study the generalized version of the problem, where the Möbius strip has a finite number n of torsions. / Neste trabalho, exploramos o elo entre geometria e propriedades físicas no caso de anéis quânticos bidimensionais. Com o foco nas estruturas mesoscópicas não-orientáveis, resolvemos o problema da faixa de Möbius quântica, um anel quântico cuja superfície de confinamento é uma faixa de Möbius, e investigamos de que maneira as propriedades físicas de tais estruturas respondem à variação geométrica característica dessa particular configuração de confinamento. Mais precisamente, investigamos o modo pelo qual a adoção de condições de contorno associadas a essa configuração geométrica específica, em particular, pode interferir nas propriedades gerais dos anéis quânticos bidimensionais. Além disso, ainda estudamos a versão generalizada do problema, em que a faixa de Möbius apresenta um número finito n de torções.
14

Grupos Discretos no Plano Hiperbólico

Silva, Carlos Antonio Guimarães 23 August 2013 (has links)
Made available in DSpace on 2015-05-15T11:46:15Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1316113 bytes, checksum: fa392778ab5ea3463805913d86fe571f (MD5) Previous issue date: 2013-08-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Set a generalization of Möbius transformation and build a theory of inductive that may be an n-dimensional hyperbolic space. This theory allows for the inductive starting with n = 1, together with the extension notion of the Poincaré build a chain groups GM(n) transformation Möbius and spaces hyperbolic H2 members. We will see explicit formulas for the Poincaré bisectors in size 2. And may on models of hiperbolic space ball these bisectors coincide with the isometric spheres of isometries. We will be using explicit formulas of bissectors, to ge youself an algorithm, the DAFC, to obtain generators for Fuchsianos groups, which will be our study group. / Definir uma generalização do conceito de transformação de Möbius e construir uma teoria indutiva do que venha a ser um espaço hiperbólico de dimensão n. Essa teoria indutiva nos permite que se iniciando com n = 1, juntamente com a noção de extensão de Poincaré, construir uma cadeia de grupos GM(n) de transformação de Möbius e os espaços hiperbólicos H2 associados. Veremos fórmulas explícitas para os bissetores de Poincaré em dimensão 2. E que nos modelos de bola do espaço hiperbólico, esses bissetores coincidem com as esferas isométricas das isometrias. Iremos usar fórmulas explícitas dos bissetores, para obter-se um algoritmo, o DAFC, para obtenção de geradores para grupos Fuchsianos, que será nosso grupo em estudo.
15

Transformação de Möbius

Santos, Marcus Vinicio de Jesus 30 August 2016 (has links)
The aim of this work is the study of arbitrary mobius transformations by means of simple complex transformations, namely: the Translation, the Rotation, the Homotetia (Contraction and Dilatation) and Inversion. The results obtained were applied in circles and straight line. At the end, we give the the alternative of studying mobius transformations via matrices. / O objetivo deste trabalho é estudar transformações de Möbius arbitrárias por meio de transformações complexas mais simples, a saber: a Translação, a Rotação, a Homotetia (Contração e Dilatação) e a Inversão. Os resultados obtidos foram aplicados em círculos e retas. No final, damos a alternativa de estudar transformações de Möbius via matrizes.
16

Rees Products of Posets and Inequalities

Brown, Tricia Muldoon 01 January 2009 (has links)
In this dissertation we will look at properties of two different posets from different perspectives. The first poset is the Rees product of the face lattice of the n-cube with the chain. Specifically we study the Möbius function of this poset. Our proof techniques include straightforward enumeration and a bijection between a set of labeled augmented skew diagrams and barred signed permutations which label the maximal chains of this poset. Because the Rees product of this poset is Cohen-Macaulay, we find a basis for the top homology group and a representation of the top homology group over the symmetric group both indexed by the set of labeled augmented skew diagrams. We also show that the Möbius function of the Rees product of a graded poset with the t-ary tree and the Rees product of its dual with the t-ary tree coincide. We discuss labelings for Rees and Segre products in general, particularly the Rees product of the face lattice of a polytope with the chain. We also look at cases where the Möbius function of a poset is equal to the permanent of a matrix and we consider local h-vectors for the barycentric subdivision of the n-cube. In each section we state open conjectures. The second poset in this dissertation is the Dowling lattice. In particular we look at the k = 1 case, that is, the partition lattice. We study inequalities on the flag vector of the partition lattice via a weighted boustrophedon transform and determine a more generalized version for the Dowling lattice. We generalize a determinantal formula of Niven and conclude with conjectures and avenues of study.
17

Exploration de la valeur de Shapley et des indices d'interaction pour les jeux définis sur des ensembles ordonnés

Lange, Fabien 14 December 2007 (has links) (PDF)
Les fonctions de treillis, apparaissent être des outils essentiels en recherche opérationnelle. Elles ouvrent en effet de nouveaux champs d'application en théorie des jeux coopératifs, et en aide à la décision (les jeux sont dans ce cas des capacités, ou mesures floues). Cette thèse a pour objet l'investigation de concepts de solutions pour les jeux définis sur des structures générales de coalitions. À cette fin, nous proposons plusieurs généralisations et axiomatisations de la valeur de Shapley pour les jeux multi-choix, les jeux à actions combinées, et les jeux réguliers. L'indice d'interaction quantifie la véritable contribution d'une coalition par rapport à toutes ses sous-coalitions. Mathématiquement, il s'agit d'un prolongement de la valeur de Shapley. Nous proposons des axiomatisations de l'indice d'interaction de Shapley pour les jeux bi-coopératifs, ainsi que des procédés calculatoires permettant de déterminer l'opérateur d'interaction et son inverse.
18

Dimensional Reduction for Identical Kuramoto Oscillators: A Geometric Perspective

Chen, Bolun January 2017 (has links)
Thesis advisor: Jan R. Engelbrecht / Thesis advisor: Renato E. Mirollo / Many phenomena in nature that involve ordering in time can be understood as collective behavior of coupled oscillators. One paradigm for studying a population of self-sustained oscillators is the Kuramoto model, where each oscillator is described by a phase variable, and interacts with other oscillators through trigonometric functions of phase differences. This dissertation studies $N$ identical Kuramoto oscillators in a general form \[ \dot{\theta}_{j}=A+B\cos\theta_{j}+C\sin\theta_{j}\qquad j=1,\dots,N, \] where coefficients $A$, $B$, and $C$ are symmetric functions of all oscillators $(\theta_{1},\dots,\theta_{N})$. Dynamics of this model live in group orbits of M\"obius transformations, which are low-dimensional manifolds in the full state space. When the system is a phase model (invariant under a global phase shift), trajectories in a group orbit can be identified as flows in the unit disk with an intrinsic hyperbolic metric. A simple criterion for such system to be a gradient flow is found, which leads to new classes of models that can be described by potential or Hamiltonian functions while exhibiting a large number of constants of motions. A generalization to extended phase models with non-identical couplings gives rise to richer structures of fixed points and bifurcations. When the coupling weights sum to zero, the system is simultaneously gradient and Hamiltonian. The flows mimic field lines of a two-dimensional electrostatic system consisting of equal amounts of positive and negative charges. Bifurcations on a partially synchronized subspace are discussed as well. / Thesis (PhD) — Boston College, 2017. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Physics.
19

Feature extraction based on a tensor image description

Westin, Carl-Fredrik January 1991 (has links)
<p>Feature extraction from a tensor based local image representation introduced by Knutsson in [37] is discussed. The tensor representation keeps statements of structure, certainty of statement and energy separate. Further processing for obtaining new features also having these three entities separate is achieved by the use of a new concept, tensor field filtering. Tensor filters for smoothing and for extraction of circular symmetries are presented and discussed in particular. These methods are used for corner detection and extraction of more global features such as lines in images. A novel method for grouping local orientation estimates into global line parameters is introduced. The method is based on a new parameter space, the Möbius Strip parameter space, which has similarities to the Hough transform. A local centroid clustering algorithm is used for classification in this space. The procedure automatically divides curves into line segments with appropriate lengths depending on the curvature. A linked list structure is built up for storing data in an efficient way.</p> / Ogiltigt nummer / annan version: I publ. nr 290:s ISBN: 91-7870-815-X.
20

Invariantes de Tutte-Grothendieck em Grafos. / Invariants of Tutte-Grothendieck in Graphs.

SILVA JÚNIOR, Aluizio Freire da. 09 July 2018 (has links)
Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-07-09T18:31:20Z No. of bitstreams: 1 ALUIZIO FREIRE DA SILVA JÚNIOR - DISSERTAÇÃO PPGMAT 2006..pdf: 980989 bytes, checksum: f1926c139600c32faa072dcabfe92429 (MD5) / Made available in DSpace on 2018-07-09T18:31:20Z (GMT). No. of bitstreams: 1 ALUIZIO FREIRE DA SILVA JÚNIOR - DISSERTAÇÃO PPGMAT 2006..pdf: 980989 bytes, checksum: f1926c139600c32faa072dcabfe92429 (MD5) Previous issue date: 2006-03 / Capes / Este trabalho tem como objetivo estabelecer algumas técnicas de T-G aplicadas a alguns problemas da teoria dos grafos, como: o problema da existência de um 6-fluxo não-nulo, problemas relacionados a orientações acíclicas, coloração a duas variáveis, e percolação. Para isto, estaremos apresentando uma pequena introdução ao polinômio de Tutte para matróides com seus principais resultados. / This work has as objective to establish some T-G techniques applied to some problems of the graph theory, as: the problem of existence of a nowhere-zero 6-flow, problems concern to acyclic orientations, two-variable coloring, and percolation. To do this, we shall present a little introduction to Tutte polynomials to matroids with its main results.

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