To see the other types of publications on this topic, follow the link: Dimension theorem.

Dissertations / Theses on the topic 'Dimension theorem'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 dissertations / theses for your research on the topic 'Dimension theorem.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.

1

Montgomery, Martin. "Dimension of certain cleft binomial rings /." view abstract or download file of text, 2006. http://proquest.umi.com/pqdweb?did=1188874501&sid=7&Fmt=2&clientId=11238&RQT=309&VName=PQD.

Full text
Abstract:
Thesis (Ph. D.)--University of Oregon, 2006.
Typescript. Includes vita and abstract. Includes bibliographical references (leaf 77). Also available for download via the World Wide Web; free to University of Oregon users.
APA, Harvard, Vancouver, ISO, and other styles
2

Shi, Ronggang. "Equidistribution of expanding measures with local maximal dimension and Diophantine Approximation." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1242259439.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Min, Aleksey. "Limit theorems for statistical functionals with applications to dimension estimation." Doctoral thesis, [S.l.] : [s.n.], 2004. http://webdoc.sub.gwdg.de/diss/2004/min/min.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Kalajdzievski, Damjan. "Measurability Aspects of the Compactness Theorem for Sample Compression Schemes." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/23133.

Full text
Abstract:
In 1998, it was proved by Ben-David and Litman that a concept space has a sample compression scheme of size $d$ if and only if every finite subspace has a sample compression scheme of size $d$. In the compactness theorem, measurability of the hypotheses of the created sample compression scheme is not guaranteed; at the same time measurability of the hypotheses is a necessary condition for learnability. In this thesis we discuss when a sample compression scheme, created from compression schemes on finite subspaces via the compactness theorem, have measurable hypotheses. We show that if $X$ is a standard Borel space with a $d$-maximum and universally separable concept class $\m{C}$, then $(X,\CC)$ has a sample compression scheme of size $d$ with universally Borel measurable hypotheses. Additionally we introduce a new variant of compression scheme called a copy sample compression scheme.
APA, Harvard, Vancouver, ISO, and other styles
5

Farkas, Ábel. "Dimension and measure theory of self-similar structures with no separation condition." Thesis, University of St Andrews, 2015. http://hdl.handle.net/10023/7854.

Full text
Abstract:
We introduce methods to cope with self-similar sets when we do not assume any separation condition. For a self-similar set K ⊆ ℝᵈ we establish a similarity dimension-like formula for Hausdorff dimension regardless of any separation condition. By the application of this result we deduce that the Hausdorff measure and Hausdorff content of K are equal, which implies that K is Ahlfors regular if and only if Hᵗ (K) > 0 where t = dim[sub]H K. We further show that if t = dim[sub]H K < 1 then Hᵗ (K) > 0 is also equivalent to the weak separation property. Regarding Hausdorff dimension, we give a dimension approximation method that provides a tool to generalise results on non-overlapping self-similar sets to overlapping self-similar sets. We investigate how the Hausdorff dimension and measure of a self-similar set K ⊆ ℝᵈ behave under linear mappings. This depends on the nature of the group T generated by the orthogonal parts of the defining maps of K. We show that if T is finite then every linear image of K is a graph directed attractor and there exists at least one projection of K such that the dimension drops under projection. In general, with no restrictions on T we establish that Hᵗ (L ∘ O(K)) = Hᵗ (L(K)) for every element O of the closure of T , where L is a linear map and t = dim[sub]H K. We also prove that for disjoint subsets A and B of K we have that Hᵗ (L(A) ∩ L(B)) = 0. Hochman and Shmerkin showed that if T is dense in SO(d; ℝ) and the strong separation condition is satisfied then dim[sub]H (g(K)) = min {dim[sub]H K; l} for every continuously differentiable map g of rank l. We deduce the same result without any separation condition and we generalize a result of Eroğlu by obtaining that Hᵗ (g(K)) = 0. We show that for the attractor (K1, … ,Kq) of a graph directed iterated function system, for each 1 ≤ j ≤ q and ε > 0 there exists a self-similar set K ⊆ Kj that satisfies the strong separation condition and dim[sub]H Kj - ε < dim[sub]H K. We show that we can further assume convenient conditions on the orthogonal parts and similarity ratios of the defining similarities of K. Using this property we obtain results on a range of topics including on dimensions of projections, intersections, distance sets and sums and products of sets. We study the situations where the Hausdorff measure and Hausdorff content of a set are equal in the critical dimension. Our main result here shows that this equality holds for any subset of a set corresponding to a nontrivial cylinder of an irreducible subshift of finite type, and thus also for any self-similar or graph directed self-similar set, regardless of separation conditions. The main tool in the proof is an exhaustion lemma for Hausdorff measure based on the Vitali's Covering Theorem. We also give several examples showing that one cannot hope for the equality to hold in general if one moves in a number of the natural directions away from `self-similar'. Finally we consider an analogous version of the problem for packing measure. In this case we need the strong separation condition and can only prove that the packing measure and δ-approximate packing pre-measure coincide for sufficiently small δ > 0.
APA, Harvard, Vancouver, ISO, and other styles
6

Fontes, Nuno Ricardo Moura. "Sistemas dinâmicos, análise numérica de séries temporais e aplicações às finanças." Master's thesis, Instituto Superior de Economia e Gestão, 2013. http://hdl.handle.net/10400.5/6454.

Full text
Abstract:
Mestrado em Matemática Financeira
Taken's theorem (1981) shows how the series of measurements from a given system can be used to reconstruct the original system's underlying dynamic process. In this work we start from this point and build a bridge between theoretical results and its practical application. Several algorithms are presented and then rebuilt in an effort to reach a middle ground between computer resources optimization and output accuracy. Among these algorithms, the biggest emphasis is put on the correlation dimension algorithm by Grassberger and Procaccia which allows for the deduction of the system's embedding dimension. The results derived are then used to build a forecast approach inspired by the analogues method. The purpose of this work is to show there is potential for dynamical systems' modelling tools to be used in financial markets, especially for intra-day purposes where decision and computational times need to be very small.
O teorema de Takens (1981) mostra como uma série de medições obtidas de um dado sistema podem ser usadas para reconstruir o sistema dinâmico original. Neste trabalho, parte-se deste teorema e constrói-se a ponte entre conceitos teóricos e a sua aplicação numérica. Vários algoritmos são apresentados e depois reconstruídos com o objetivo de se atingir um compromisso entre otimização de recursos computacionais e rigor nos resultados. Entre esses algoritmos, a maior ênfase é colocada no do cálculo do integral de correlação de Grassberger-Procaccia que permite a dedução da dimensão de imersão de um dado sistema. Os resultados obtidos são usados na construção de um modelo de previsão inspirado pela abordagem dos pontos análogos, ou método dos análogos. O objetivo deste trabalho é mostrar que existe potencial na aplicação de ferramentas de modelação de sistemas dinâmicos caóticos no mercado financeiro, em especial em transações intra-diárias onde tempos de decisão e computação têm de ser muito reduzidos.
APA, Harvard, Vancouver, ISO, and other styles
7

Joanpere, Salvadó Meritxell. "Fractals and Computer Graphics." Thesis, Linköpings universitet, Matematiska institutionen, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-68876.

Full text
Abstract:
Fractal geometry is a new branch of mathematics. This report presents the tools, methods and theory required to describe this geometry. The power of Iterated Function Systems (IFS) is introduced and applied to produce fractal images or approximate complex estructures found in nature. The focus of this thesis is on how fractal geometry can be used in applications to computer graphics or to model natural objects.
APA, Harvard, Vancouver, ISO, and other styles
8

Pötzelberger, Klaus. "The General Quantization Problem for Distributions with Regular Support." Department of Statistics and Mathematics, WU Vienna University of Economics and Business, 1999. http://epub.wu.ac.at/1508/1/document.pdf.

Full text
Abstract:
We study the asymptotic behavior of the quantization error for general information functions and prove results for distributions P with regular support. We characterize the information functions for which the uniform distribution on the set of prototypes converges weakly to P. (author's abstract)
Series: Forschungsberichte / Institut für Statistik
APA, Harvard, Vancouver, ISO, and other styles
9

Freire, Ageu Barbosa. "Cúbicas Reversas e Redes de Quádricas." Universidade Federal da Paraíba, 2016. http://tede.biblioteca.ufpb.br:8080/handle/tede/9275.

Full text
Abstract:
Submitted by ANA KARLA PEREIRA RODRIGUES (anakarla_@hotmail.com) on 2017-08-17T12:22:57Z No. of bitstreams: 1 arquivototal.pdf: 697305 bytes, checksum: 0b28f8f8c4f8b4509047eb441817be7c (MD5)
Made available in DSpace on 2017-08-17T12:22:57Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 697305 bytes, checksum: 0b28f8f8c4f8b4509047eb441817be7c (MD5) Previous issue date: 2016-03-09
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
In this work, we present an explicit geometric characterization for the space of quadratcs form vanishing precisely on a twisted cubic. We show that the set of degenerate quadrics lying on a net of quadrics containing a twisted cubic is described by a curve whose equation is given by the square of an irreducible conic. Conversely, if is a net of quadrics whosw intersection with the set of degenerate quadrics is a curve given by the square of an irreducible conic, we furnish conditions under which the cammon zero locus of turns out to be a twisted cubic. It is enough to require that does not contain a pair of planes.
Neste trabalho, apresentamos uma caracteriza c~ao geom etrica expl cita para o espa co das formas quadr aticas que se anulam precisamente sobre uma c ubica reversa. Mostramos que o conjunto das qu adricas degeneradas pertencentes a uma rede de qu adricas que cont em a c ubica reversa e descrita por uma curva cuja equa c~ao e dada pelo quadrado de uma c^onica irredut vel. Rec procamente, se e uma rede de qu adricas cuja interse c~ao com o conjunto das qu adricas n~ao degeneradas e uma curva dada pelo quadrado de uma c^onica irredut vel, fornecemos condi c~oes sob as quais o lugar dos zeros comuns de seja uma c ubica reversa. E su ciente que n~ao contenha um par de plano.
APA, Harvard, Vancouver, ISO, and other styles
10

Debin, Clément. "Géométrie des surfaces singulières." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAM078/document.

Full text
Abstract:
La recherche d'une compactification de l'ensemble des métriques Riemanniennes à singularités coniques sur une surface amène naturellement à l'étude des "surfaces à Courbure Intégrale Bornée au sens d'Alexandrov". Il s'agit d'une géométrie singulière, développée par A. Alexandrov et l'école de Leningrad dans les années 1970, et dont la caractéristique principale est de posséder une notion naturelle de courbure, qui est une mesure. Cette large classe géométrique contient toutes les surfaces "raisonnables" que l'on peut imaginer.Le résultat principal de cette thèse est un théorème de compacité pour des métriques d'Alexandrov sur une surface ; un corollaire immédiat concerne les métriques Riemanniennes à singularités coniques. On décrit dans ce manuscrit trois hypothèses adaptées aux surfaces d'Alexandrov, à la manière du théorème de compacité de Cheeger-Gromov qui concerne les variétés Riemanniennes à courbure bornée, rayon d'injectivité minoré et volume majoré. On introduit notamment la notion de rayon de contractibilité, qui joue le rôle du rayon d'injectivité dans ce cadre singulier.On s'est également attachés à étudier l'espace (de module) des métriques d'Alexandrov sur la sphère, à courbure positive le long d'une courbe fermée. Un sous-ensemble intéressant est constitué des convexes compacts du plan, recollés le long de leurs bords. A la manière de W. Thurston, C. Bavard et E. Ghys, qui ont considéré l'espace de module des polyèdres et polygones (convexes) à angles fixés, on montre que l'identification d'un convexe à sa fonction de support fait naturellement apparaître une géométrie hyperbolique de dimension infinie, dont on étudie les premières propriétés
If we look for a compactification of the space of Riemannian metrics with conical singularities on a surface, we are naturally led to study the "surfaces with Bounded Integral Curvature in the Alexandrov sense". It is a singular geometry, developed by A. Alexandrov and the Leningrad's school in the 70's, and whose main feature is to have a natural notion of curvature, which is a measure. This large geometric class contains any "reasonable" surface we may imagine.The main result of this thesis is a compactness theorem for Alexandrov metrics on a surface ; a straightforward corollary concerns Riemannian metrics with conical singularities. We describe here three hypothesis which pair with the Alexandrov surfaces, following Cheeger-Gromov's compactness theorem, which deals with Riemannian manifolds with bounded curvature, injectivity radius bounded by below and volume bounded by above. Among other things, we introduce the new notion of contractibility radius, which plays the role of the injectivity radius in this singular setting.We also study the (moduli) space of Alexandrov metrics on the sphere, with non-negative curvature along a closed curve. An interesting subset is the set of compact convex sets, glued along their boundaries. Following W. Thurston, C. Bavard and E. Ghys, who considered the moduli space of (convex) polyhedra and polygons with fixed angles, we show that the identification between a convex set and its support function give rise to an infinite dimensional hyperbolic geometry, for which we study the first properties
APA, Harvard, Vancouver, ISO, and other styles
11

Spear, Donald W. "Hausdorff, Packing and Capacity Dimensions." Thesis, University of North Texas, 1989. https://digital.library.unt.edu/ark:/67531/metadc330990/.

Full text
Abstract:
In this thesis, Hausdorff, packing and capacity dimensions are studied by evaluating sets in the Euclidean space R^. Also the lower entropy dimension is calculated for some Cantor sets. By incorporating technics of Munroe and of Saint Raymond and Tricot, outer measures are created. A Vitali covering theorem for packings is proved. Methods (by Taylor and Tricot, Kahane and Salem, and Schweiger) for determining the Hausdorff and capacity dimensions of sets using probability measures are discussed and extended. The packing pre-measure and measure are shown to be scaled after an affine transformation. A Cantor set constructed by L.D. Pitt is shown to be dimensionless using methods developed in this thesis. A Cantor set is constructed for which all four dimensions are different. Graph directed constructions (compositions of similitudes follow a path in a directed graph) used by Mauldin and Willjams are presented. Mauldin and Williams calculate the Hausdorff dimension, or, of the object of a graph directed construction and show that if the graph is strongly connected, then the a—Hausdorff measure is positive and finite. Similar results will be shown for the packing dimension and the packing measure. When the graph is strongly connected, there is a constant so that the constant times the Hausdorff measure is greater than or equal to the packing measure when a subset of the realization is evaluated. Self—affine Sierpinski carpets, which have been analyzed by McMullen with respect to their Hausdorff dimension and capacity dimension, are analyzed with respect to their packing dimension. Conditions under which the Hausdorff measure of the construction object is positive and finite are given.
APA, Harvard, Vancouver, ISO, and other styles
12

Frere, Scot M. (Scot Martin). "Dimension Theory." Thesis, North Texas State University, 1986. https://digital.library.unt.edu/ark:/67531/metadc500690/.

Full text
Abstract:
This paper contains a discussion of topological dimension theory. Original proofs of theorems, as well as a presentation of theorems and proofs selected from Ryszard Engelking's Dimension Theory are contained within the body of this endeavor. Preliminary notation is introduced in Chapter I. Chapter II consists of the definition of and theorems relating to the small inductive dimension function Ind. Large inductive dimension is investigated in Chapter III. Chapter IV comprises the definition of covering dimension and theorems discussing the equivalence of the different dimension functions in certain topological settings. Arguments pertaining to the dimension o f Jn are also contained in Chapter IV.
APA, Harvard, Vancouver, ISO, and other styles
13

Bel, Haj Frej Ghazi. "Estimation et commande décentralisée pour les systèmes de grandes dimensions : application aux réseaux électriques." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0139/document.

Full text
Abstract:
Les travaux de cette thèse portent sur l’estimation et la commande décentralisée des systèmes de grande dimension. L’objectif est de développer des capteurs logiciels pouvant produire une estimation fiable des variables nécessaires pour la stabilisation des systèmes non linéaires interconnectés. Une décomposition d’un tel système de grande dimension en un ensemble de n sous-systèmes interconnectés est primordiale. Ensuite, en tenant compte de la nature du sous-système ainsi que les fonctions d’interconnexions, des lois de commande décentralisées basées observateurs ont été synthétisées. Chaque loi de commande est associée à un sous-système qui permet de le stabiliser localement, ainsi la stabilité du système global est assurée. L’existence d’un observateur et d’un contrôleur stabilisant le système dépend de la faisabilité d’un problème d’optimisation LMI. La formulation LMI, basée sur l’approche de Lyapunov, est élaborée par l’utilisation de principe de DMVT sur la fonction d’interconnexion non linéaire supposée bornée et incertaine. Ainsi des conditions de synthèse non restrictives sont obtenues. Des méthodes de synthèse de loi de commande décentralisée basée observateur ont été proposées pour les systèmes non linéaires interconnectés dans le cas continu et dans le cas discret. Des lois de commande robuste H1 décentralisées sont élaborées pour les systèmes non linéaires interconnectés en présence de perturbations et des incertitudes paramétriques. L’efficacité et la validation des approches présentées sont testées sur un modèle de réseaux électriques composé de trois générateurs interconnectés
This thesis focuses on the decentralized estimation and control for large scale systems. The objective is to develop software sensors that can produce a reliable estimate of the variables necessary for the interconnected nonlinear systems stability analysis. A decomposition of a such large system into a set of n interconnected subsystems is paramount for model simplification. Then, taking into account the nature of the subsystem as well as the interconnected functions, observer-based decentralized control laws have been synthesized. Each control law is associated with a subsystem which allows it to be locally stable, thus the stability of the overall system is ensured. The existence of an observer and a controller gain matrix stabilizing the system depends on the feasibility of an LMI optimization problem. The LMI formulation, based on Lyapunov approach, is elaborated by applying the DMVT technique on the nonlinear interconnection function, assumed to be bounded and uncertain. Thus, non-restrictive synthesis conditions are obtained. Observer-based decentralized control schemes have been proposed for nonlinear interconnected systems in the continuous and discrete time. Robust Hinfini decentralized controllers are provided for interconnected nonlinear systems in the presence of perturbations and parametric uncertainties. Effectiveness of the proposed schemes are verified through simulation results on a power systems with interconnected machines
APA, Harvard, Vancouver, ISO, and other styles
14

Söderberg, Alexander. "Anomalous Dimensions in the WF O(N) Model with a Monodromy Line Defect." Thesis, Uppsala universitet, Teoretisk fysik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-317546.

Full text
Abstract:
General ideas in the conformal bootstrap program are covered. Both numerical and analytical approaches to the bootstrap equation are reviewed to show how it can be manipulated in different ways. Further analytical approaches are studied for theories with defects. We consider the three-dimensional CFT at the corresponding WF fixed point in the O(N) \phi^4 model with a co-dimension two, monodromy defect. Anomalous dimensions for bulk- and defect-local fields as well as one of the OPE coefficients are found to the first loop order. Implications of inserting this defect and constraints that arises from symmetries of the theory are investigated.
APA, Harvard, Vancouver, ISO, and other styles
15

Wissanji, Alisha. "F-theory and M-theory perspectives on N=2 supersymmetric gauge theories in four dimensions." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=114221.

Full text
Abstract:
Deformations of the original F-theory background are proposed. These lead to multiple new dualities and physical phenomena. We concentrate on one model where we let seven-branes wrap a multi-centered Taub-NUT space instead of R4. This configuration provides a successful F-theory embedding of a class of recently proposed four-dimensional N = 2 superconformal (SCFT) à la Gaiotto. Aspects of Argyres- Seiberg duality, of the new Gaiotto duality, as well as of the branes network of Benini- Benvenuti and Tachikawa are captured by our construction. The supergravity theory for the conformal case is also briefly discussed. Extending our construction to the non-conformal case, we find interesting cascading behavior in four-dimensional gauge theories with N = 2 supersymmetry. Since the analysis of this unexpected phenomenon is quite difficult in the language of type IIB/F-theory, we turn to the type IIA/M-theory description where the origin of the N = 2 cascade is clarified. Using the T-dual type IIA brane language, we first start by studying the N = 1 supersymmetric cascading gauge theory found in type IIB string theory on p regular and M fractional D3-branes at the tip of the conifold. We reproduce the supersymmetric vacuum struc- ture of this theory. We also show that the IIA analog of the non-supersymmetric state found by Kachru, Pearson and Verlinde in the IIB description is metastable in string theory, but the barrier for tunneling to the supersymmetric vacuum goes to infinity in the field theory limit. We then use the techniques we have developed to analyze the N = 2 supersymmetric gauge theory corresponding to regular and fractional D3-branes on a near-singular K3, and clarify the origin of the cascade in this theory.
Différentes déformations de la géométrie originale de la théorie F sont proposées. Ces dernières génèrent une multitude de nouvelles dualités ainsi que de nouveaux phénomènes physiques. Nous nous concentrons sur un seul modèle où les membranes en sept dimensions spatiales s'enveloppent autour d'un espace Taub-NUT avec multi-centres au lieux de l'espace R4 original. Cette configuration génère avec succès la réalisation, en théorie F, d'une famille de théories de jauges superconformes en quatres dimensions avec N = 2 supersymétries nouvellement proposées par Gaiotto. Deplus, plusieurs aspects de la dualité d'Argyres-Seiberg, de la nouvelle dualité de Gaiotto ainsi que du réseaux de membranes de Benini-Benvenuti et Tachikawa sont réalisés par notre construction. La théorie de supergravité pour le cas conforme est brièvement discutée. La généralisation de notre construction au cas non-conforme mène à l'observation surprenante de cascade chez les théories de jauges avec N = 2 supersymétries en quatres dimensions. Puisque l'analyse de ce phénomène est difficile dans le language de type IIB/ théorie F, nous nous tournons vers le type IIA/theorie M où l'origine de ce phénomène est élucidée. En utilisant le langage des membranes en type IIA sous la dualité-T, nous débutons par l'étude de cascade chez les théories de jauges avec N = 1 supersymétrie tel que présenté en type IIB avec p membranes D3 régulières et M membranes D3 fractionnaires situées au bout d'un espace conifold. Nous reproduisons avec succès la structure du vide supersymétrique de cette théorie. Aussi, nous démontrons que l'analogue en type IIA des états non-supersymmetriques découverts par Kachru, Pearson et Verlinde en type IIB sont métastables en théorie des cordes alors que la barrière permettant de passer au vide supersymmetrique tant vers l'infinie dans la limite de la théorie des champs. Nous utilisons finalement les techniques que nous avons développées afin d'analyser la théorie de jauge supersymmétrique avec N = 2 correspondante à des membranes D3 régulières et fractionnaires sur un espace K3 presque singulier et clarifions l'origine du mécanisme de cascade dans cette théorie.
APA, Harvard, Vancouver, ISO, and other styles
16

Kozhevnikov, Artem. "Propriétés métriques des ensembles de niveau des applications différentiables sur les groupes de Carnot." Thesis, Paris 11, 2015. http://www.theses.fr/2015PA112073/document.

Full text
Abstract:
Nous étudions les propriétés métriques locales des ensembles de niveau des applicationshorizontalement différentiables entre des groupes de Carnot, c'est-à-dire différentiable par rapport à la structure sous-riemannienne intrinsèque.Nous considérons des applications dont la différentielle horizontale est surjective,et notre étude peut être vue comme une généralisation du théorème des fonctions implicites pour les groupes de Carnot.Tout d'abord, nous présentons deux notions de tangence dans les groupes de Carnot:la première basée sur la condition de platitude au sens de Reifenberg et la deuxième issue de l'analyse convexe classique.Nous montrons que dans les deux cas, l'espace tangent à un ensemble de niveau coïncide avec le noyau de la différentielle horizontale.Nous montrons que cette condition de tangence caractérise en fait les ensembles de niveaudits ‘co-abéliens', c'est-à-dire ceux pour lesquels l'espace d'arrivée est abélien, et qu'une telle caractérisation n'est pas vraie en général.Ce résultat sur les espaces tangents a plusieurs conséquences remarquables.La plus importante est que la dimension de Hausdorff des ensembles de niveau est celle à laquelle l'on s'attend.Nous montrons également la connectivité locale des ensembles de niveau, et le fait que les ensembles de niveau de dimension 1 sont topologiquement des arcs simples.Pour les ensembles de niveau de dimension 1 nous trouvons une formule de l'aire qui permet d'exprimer la mesure de Hausdorff en termes d'intégrales de Stieltjes généralisées.Ensuite, nous menons une étude approfondie du cas particulier des ensembles de niveau dans les groupes d'Heisenberg.Nous montrons que les ensembles de niveau sont topologiquement équivalents à leurs espaces tangents.Il s'avère que la mesure de Hausdorff des ensembles de niveau de codimension élevée est souvent irrégulière, étant, par exemple, localement nulle ou infinie.Nous présentons une condition simple de régularité supplémentaire pour une application pour assurer la régularité au sens d'Ahlfors des ses ensembles de niveau.Parmi d'autres résultats, nous obtenons une nouvelle caractérisation généraledes graphes Lipschitziens associés à une décomposition en produit semi-direct d'un groupe de Carnot.Nous traitons, en particulier, le cas des groupes de Carnot dont le nombre de stratesest plus grand que $2$.Cette caractérisation nous permet de déduire une nouvelle caractérisation des ensemblesde niveau co-abéliens qui admettent une représentation en tant que graphe
Metric properties of level sets of differentiable maps on Carnot groupsAbstract.We investigate the local metric properties of level sets of mappings defined between Carnot groups that are horizontally differentiable, i.e.with respect to the intrinsic sub-Riemannian structure. We focus on level sets of mapping having a surjective differential,thus, our study can be seen as an extension of implicit function theorem for Carnot groups.First, we present two notions of tangency in Carnot groups: one based on Reifenberg's flatness condition and another coming from classical convex analysis.We show that for both notions, the tangents to level sets coincide with the kernels of horizontal differentials.Furthermore, we show that this kind of tangency characterizes the level sets called ``co-abelian'', i.e.for which the target space is abelian andthat such a characterization may fail in general.This tangency result has several remarkable consequences.The most important one is that the Hausdorff dimension of the level sets is the expected one. We also show the local connectivity of level sets and, the fact that level sets of dimension one are topologically simple arcs.Again for dimension one level set, we find an area formula that enables us to compute the Hausdorff measurein terms of generalized Stieltjes integrals.Next, we study deeply a particular case of level sets in Heisenberg groups. We show that the level sets in this case are topologically equivalent to their tangents.It turns out that the Hausdorff measure of high-codimensional level sets behaves wildly, for instance, it may be zero or infinite.We provide a simple sufficient extra regularity condition on mappings that insures Ahlfors regularity of level sets.Among other results, we obtain a new general characterization of Lipschitz graphs associated witha semi-direct splitting of a Carnot group of arbitrary step.We use this characterization to derive a new characterization of co-ablian level sets that can be represented as graphs
APA, Harvard, Vancouver, ISO, and other styles
17

Sushma, Kumari. "Topics in random matrices and statistical machine learning." Kyoto University, 2018. http://hdl.handle.net/2433/235047.

Full text
APA, Harvard, Vancouver, ISO, and other styles
18

Schmutz, Christina. "La dimensión crítica del teatro de Roger Bernat, René Pollesch y Christina Schmutz/ Frithwin Wagner-Lippok. Uso de texto y reflexión crítica en la conjunción de teoría y práctica. Una aproximación fenomenológica a Numax-Fagor-Plus, Kill Your Darlings! Streets of Berladelphia y els suplicants//conviure a bcn." Doctoral thesis, Universitat Autònoma de Barcelona, 2018. http://hdl.handle.net/10803/650283.

Full text
Abstract:
La dimensión crítica del teatro puede verse, de acuerdo con el concepto de lo crítico de Foucault, en su enfrentamiento a los nuevos retos sociales desde una postura de insumisión. Dicho teatro trata de emanciparse de las expectativas externas y hallar autocríticamente normas propias. Puede describírsele a partir de los aspectos de crisis, crítica y diferenciación (de interpretaciones), inherentes al concepto de lo crítico, y opera con la ampliación de espacios de posibilidades. Ante el panorama teórico e histórico de lo crítico en las estéticas teatrales postdramática (Hans-Thies Lehmann) y postespectacular (André Eiermann), el presente trabajo estudia la función escénica del texto. Dicha función se funde dentro del estudio fenomenológico en el concepto de uso de texto, que contiene a partes iguales la generación y la aparición de texto verbal en la realización escénica, y se reconstruye a partir de la experiencia propia de la realización. Al mismo tiempo, el estudio pretende extraer conclusiones de cómo un uso de texto específico despliega una capacidad crítica. Como recurso adicional se empleará la dimensión de distancia/inmersión, cuyo extremo de distancia está conceptualmente relacionado con un postulado básico de la estética postespectacular: la recuperación de una distancia poéticamente eficaz entre escenario y público; en cambio, su extremo de inmersión se sitúa cercano a un postulado central de la estética postdramática: la fusión y desintegración de límites y la comunicación inmediata entre escenario y público. Así pues, cabe preguntarse en qué medida los fenómenos inmersivos y distanciadores estimulan u obstaculizan lo crítico de una realización escénica o si resultan indiferentes o ambiguos en relación a lo crítico. El trabajo estudia sobre la base de tres paradigmas teatrales seleccionados cómo aparece el texto verbal experimentable en la realización escénica y qué relaciones se generan entre dichos fenómenos y la dimensión crítica de la realización escénica. Las cualidades semánticas de los textos no juegan sino un papel indirecto para el concepto de uso de texto usado aquí. Si bien pueden guardar relación con la aparición del texto, como tal dejan de ser objeto del planteamiento. La definición de uso de texto se limita al texto verbal, entendido como texto formado lingüísticamente en sentido estricto. En cambio, no incluye los signos de lenguaje corporal o el «texto» en el sentido de un concepto semiótico ampliado, en calidad de «textura», de una realización escénica (como en el concepto de «realización escénica como texto»). Como material de estudio de los planteamientos mencionados sirven los siguientes tres paradigmas: Kill your Darlings! Streets of Berladelphia (2012 René Pollesch), Numax-Fagor-Plus (2013 Roger Bernat) y els suplicants//conviure a bcn (2015 Christina Schmutz y Frithwin Wagner-Lippok). Dado que la aparición de texto se sitúa en primer plano, la orientación fenomenológica del estudio parece adecuada para poder extraer conclusiones acerca de cómo se experimenta el texto en una realización escénica de teatro. El método fenomenológico trata de prescindir de todo apriorismo y conocimiento previo («reducción fenomenológica»), tal y como se expresa o se supone en contenidos de texto. Bajo uso de texto se entienden los fenómenos de texto verbal experimentables sensorialmente, tal y como aparecen en el momento de la realización escénica y el recuerdo posterior. Las experiencias procedentes de la perspectiva subjetiva se abstraen en el análisis fenomenológico hacia un contexto comunicable que permite unas respuestas supraindividuales al planteamiento.
The aesthetical and critical dimension of theatre performance consists in getting involved in a challenge with the surrounding world by not only reproducing its features but developing a critical attitude towards it. Under this assumption, the present study examines the function and use of text in theatrical performances, trying to explore possibilities and implications of the use of text with respect to its critical dimension and against the historical background of criticism in postdramatic (Hans-Thies Lehmann) and postspectacular (André Eiermann) aethetics. The study aims to recognize what kinds of usage or appearance of verbal text may display a critical potential. As an additional investigation device, the dimension distance-immersion will be applied as a sort of investigation tool providing a heuristically promising sensor in analyzing paradigmatic performances, the distance pole of which has a conceptual affinity with one core postulate of postspectacular aesthetics while its immersive pole shows some inclination towards a core feature of postdramatic aesthetics. The question then is if and how immersive and distancing fenomena might promote or inhibit critical aspects of the performance, or if they prove to be indifferent or ambivalent in this respect. The project evaluates three selected performance examples with regard to how verbal text in the performance is used, or comes to the fore, and by which contexts these appearances may be connected to the critical aspect of the performance. Internal text qualities such as its semantic substance, even though bound to the appearance of text, anyway, play but an indirect role in the present concept, being not as such an objective of the research question. The concept of text use is in fact limited to verbal text, that is, to text structures in a narrow linguistic sense. Text concepts in the sense of non-verbal signals, as in body language, or of texture, as in the context of performance as text, are not taken into consideration. René Pollesch’s Kill your Darlings. Streets of Berladelphia, premiered 2012 in Berlin, Roger Bernat’s Numax Fagor Plus, Barcelona 2013, and Christina Schmutz’ and Frithwin Wagner-Lippok’s els suplicants//conviure a bcn, Barcelona 2015, will serve as paradigms. As in this investigation, instead of semantic qualities, the appearance of text in the performance is at stake, a phenomenological approach is taken, which seems particularly suitable for the investigation of the „thing itself“, that is, the experience – not the content – of text in performances, which is naturally connected with its appearance. Trying to refrain from any preceding meaning and knowledge („phenomenological reduction“) that might appear or be inferred from the text’s content, the phenomenological method addresses itself to the text’s immediate experience, that is, to its sensual and physical appearance. Phenomena hereby are all emergences of verbal text, manifesting in one’s own experience in the presence of a performance or reminiscence. Arising from the subjective perspective, this experience is phenomenologically analyzed by help of other contexts and correspondences structurally entangled with it.
APA, Harvard, Vancouver, ISO, and other styles
19

Barragán, Ramírez Gabriel Antonio. "On the local metric dimension of graphs." Doctoral thesis, Universitat Rovira i Virgili, 2017. http://hdl.handle.net/10803/442981.

Full text
Abstract:
La dimensió mètrica d'un espai mètric general es va introduir el 1953, però va atreure poca atenció fins que, uns vint anys més tard, es va aplicar a les distàncies entre els vèrtexs d'un graf. Des de llavors s'ha utilitzat amb freqüència en la teoria de grafs, la química, la biologia, la robòtica i moltes altres disciplines. A causa de la multiplicitat de situacions de les que pot sorgir el problema de distingir els vèrtexs d'un graf, diverses variants del concepte original de la dimensió mètrica ha anat apareixent en la literatura especialitzada. En aquesta tesi s'estudia una d'aquestes variants, és a dir, la dimensió mètrica local. En concret, aquesta tesi ens centrem en el problema de calcular la dimensió mètrica local de grafs. En primer lloc, presentem l'estat de l'art de la dimensió mètrica local i obtenim alguns resultats originals en els que caracteritzem tots els grafs que atenyen algunes fites conegudes. En segon lloc, obtenim fórmules tancades i fites tenses per a la dimensió mètrica local de diverses famílies de grafs, incloent grafs producte fort, grafs corona i grafs producte lexicogràfic. Finalment, introduïm l'estudi de la dimensió mètrica local simultània i donem alguns resultats generals en aquesta nova línia d'investigació.
La dimensión métrica de un espacio métrico general fue introducida en 1953, pero atrajo poca atención hasta que, aproximadamente veinte años más tarde, se aplicó a las distancias entre vértices de un gráfico. Desde entonces se ha utilizado con frecuencia en la teoría de los gráficos, la química, la biología, la robótica y muchas otras disciplinas. Debido a la multiplicidad de situaciones desde las que puede surgir el problema de distinguir los vértices de un gráfico, en la literatura especializada han aparecido varias variantes del concepto original de dimensión métrica. En esta tesis estudiamos una de estas variantes, a saber, la dimensión métrica local. En particular, nos centramos en el problema de calcular la dimensión métrica local de grafos. Primero presentamos el estado del arte de la dimensión métrica local y presentamos algunos resultados originales en los que caracterizamos todos los grafos que alcanzan algunas de las cotas conocidas. En segundo lugar, obtenemos fórmulas cerradas y cotas tensas para la dimensión métrica local de varias familias de grafos, entre los que destacamos los grafos producto fuerte, grafos corona y grafos producto lexicográfico. Finalmente, introducimos el estudio de la dimensión métrica local simultánea y damos algunos resultados generales en esta nueva línea de investigación.
The metric dimension of a general metric space was introduced in 1953 but attracted little attention until, about twenty years later, it was applied to the distances between vertices of a graph. Since then it has been frequently used in graph theory, chemistry, biology, robotics and many other disciplines. Due to the variety of situations from which the problem of distinguishing the vertices of a graph can arise, several variants of the original concept of metric dimension have been appearing in specialized literature. In this thesis we study one of these variants, namely, the local metric dimension. Specifically, we focus on the problem of computing the local metric dimension of graphs. We first report on the state of the art on the local metric dimension and present some original results in which we characterize all graphs that reach some known bounds. Secondly, we obtain closed formulas and tight bounds on the local metric dimension of several families of graphs, including strong product graphs, corona product graphs, rooted product graphs and lexicographic product graphs. Finally, we introduce the study of simultaneous local metric dimension and we give some general results on this new research line.
APA, Harvard, Vancouver, ISO, and other styles
20

Šlekys, Deividas. "Military as the Forgotten Dimension of Political Theory." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2012. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2012~D_20120302_090514-90493.

Full text
Abstract:
The dissertation seeks to modify, update and bring back the tradition of political theory which based its understanding of political in the state and the society mainly on the perspective of the military dimension. The dissertation argues this forgetfulness creates serious obstacles when trying to understand contemporary military changes and their wider implications. Historical turn of political science is seen as a way to make this update real. Historical notion of Military revolution is seen as specific conceptual “tool” that will make this turn. Using historiographical analysis development of military revolution, changing character of war, transformation of armed forces and development of American civil-military, military and police relations are discussed. American case is analysed because by being the most militarily advanced Western state this country had to felt first the effect of changes in state and society caused by military transformation.
Disertacijoje siekiama išsiaiškinti, kodėl buvo užmiršta mastymo tradicija, kuri politinius veiksmus valstybėje ir visuomenėje aiškina remdamasi karine perspektyva. Ši mastymo tradicija gali būti „atrasta“ pasitelkus istorinę perspektyvą bei istorikų pasiūlyta Karinės revoliucijos (angl. military revolution) idėja. Darbe apžvelgiama „karingų“ politikos teorijų raida ir priežastys, kodėl jos buvo užmirštos aptarimui. Pasitelkus istoriografinę analizę yra detaliai aptariama Karinės revoliucijos idėjos raida, karo pobūdžio kaita, karinės organizacijos transformacija. Istoriškai valstybės karinėje srityje kopijuodavo dominuojančios, paradigminės valstybės karines (technologines, konceptualines, socialines) praktikas. Todėl darbe yra aptariama JAV kariškių ir civilių santykių bei Amerikos kariuomenės ir policijos institucijų sąveikos būklė, nes manoma, jog būdamos stipriausia karinė galybė pasaulyje JAV anksčiau už kitas Vakarų valstybes patiria pokyčius, aptariamus šioje disertacijoje.
APA, Harvard, Vancouver, ISO, and other styles
21

Ferguson, Andrew J. "Dimension theory and dynamically defined sets." Thesis, University of Warwick, 2011. http://wrap.warwick.ac.uk/55922/.

Full text
Abstract:
The first topic of this thesis is concerned with the application of the continuous perturbation theory of Keller and Liverani to investigate the statistical properties of dynamical systems with holes. The main result of Chapter 3 is a perturbation result for a singularly perturbed transfer operator in the setting of subshifts of finite type. Chapter 4 investigates the consequences of this result for an expanding map of a compact metric space. In this chapter results laws concerning escape rates, extreme value theory, Hausdorff dimension and return time statistics are derived. The second main component of the thesis is the study of the orthogonal projection of dynamically defined sets in the plane. In Chapter 5 we build on the work of Peres and Shmerkin, proving that if an irrationality condition holds for certain classes of dynamically defined planar sets then the exceptional set of directions in Marstrand’s theorem can be computed explicitly.
APA, Harvard, Vancouver, ISO, and other styles
22

Lau, Richard. "SO(N) gauge theories in 2+1 dimensions." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:fa9dae0a-70c2-467a-8aa7-daff5531ff10.

Full text
Abstract:
We calculate the string tensions, mass spectrum, and deconfining temperatures of SO(N) gauge theories in 2+1 dimensions. After a review of lattice field theory, we describe how we simulate the corresponding lattice gauge theories, construct operators to project on to specific states, and extrapolate values to the continuum limit. We discuss how to avoid possible complications such as finite size corrections and the bulk transition. SO(N) gauge theories have become recently topical since they do not have a fermion sign problem, are orbifold equivalent to SU(N) gauge theories, and share a common large-N limit in their common sector of states with SU(N) gauge theories. This motivates us to compare the physical properties of SO(N) and SU(N) gauge theories between 'group equivalences', which includes Lie algebra equivalences such as SO(6) and SU(4), and particularly a large-N equivalence. We discuss the large-N orbifold equivalence between SO(N) and SU(N) gauge theories, which relates the large-N gauge theories perturbatively. Using large-N extrapolations at fixed 't Hooft coupling, we test to see if SO(N) gauge theories and SU(N) gauge theories share non-perturbative properties at the large-N limit. If these group equivalences lead to similar physics in the gauge theories, then we could imagine doing finite chemical potential calculations that are currently intractable in SU(N) gauge theories by calculating equivalent quantities in the corresponding SO(N) gauge theories. We show that the SO(N) and SU(N) values match between group equivalences and at the large-N limit.
APA, Harvard, Vancouver, ISO, and other styles
23

Fraser, Jonathan M. "Dimension theory and fractal constructions based on self-affine carpets." Thesis, University of St Andrews, 2013. http://hdl.handle.net/10023/3869.

Full text
Abstract:
The aim of this thesis is to develop the dimension theory of self-affine carpets in several directions. Self-affine carpets are an important class of planar self-affine sets which have received a great deal of attention in the literature on fractal geometry over the last 30 years. These constructions are important for several reasons. In particular, they provide a bridge between the relatively well-understood world of self-similar sets and the far from understood world of general self-affine sets. These carpets are designed in such a way as to facilitate the computation of their dimensions, and they display many interesting and surprising features which the simpler self-similar constructions do not have. For example, they can have distinct Hausdorff and packing dimensions and the Hausdorff and packing measures are typically infinite in the critical dimensions. Furthermore, they often provide exceptions to the seminal result of Falconer from 1988 which gives the `generic' dimensions of self-affine sets in a natural setting. The work in this thesis will be based on five research papers I wrote during my time as a PhD student. The first contribution of this thesis will be to introduce a new class of self-affine carpets, which we call box-like self-affine sets, and compute their box and packing dimensions via a modified singular value function. This not only generalises current results on self-affine carpets, but also helps to reconcile the `exceptional constructions' with Falconer's singular value function approach in the generic case. This will appear in Chapter 2 and is based on a paper which appeared in 'Nonlinearity' in 2012. In Chapter 3 we continue studying the dimension theory of self-affine sets by computing the Assouad and lower dimensions of certain classes. The Assouad and lower dimensions have not received much attention in the literature on fractals to date and their importance has been more related to quasi-conformal maps and embeddability problems. This appears to be changing, however, and so our results constitute a timely and important contribution to a growing body of literature on the subject. The material in this Chapter will be based on a paper which has been accepted for publication in 'Transactions of the American Mathematical Society'. In Chapters 4-6 we move away from the classical setting of iterated function systems to consider two more exotic constructions, namely, inhomogeneous attractors and random 1-variable attractors, with the aim of developing the dimension theory of self-affine carpets in these directions. In order to put our work into context, in Chapter 4 we consider inhomogeneous self-similar sets and significantly generalise the results on box dimensions obtained by Olsen and Snigireva, answering several questions posed in the literature in the process. We then move to the self-affine setting and, in Chapter 5, investigate the dimensions of inhomogeneous self-affine carpets and prove that new phenomena can occur in this setting which do not occur in the setting of self-similar sets. The material in Chapter 4 will be based on a paper which appeared in 'Studia Mathematica' in 2012, and the material in Chapter 5 is based on a paper, which is in preparation. Finally, in Chapter 6 we consider random self-affine sets. The traditional approach to random iterated function systems is probabilistic, but here we allow the randomness in the construction to be provided by the topological structure of the sample space, employing ideas from Baire category. We are able to obtain very general results in this setting, relaxing the conditions on the maps from `affine' to `bi-Lipschitz'. In order to get precise results on the Hausdorff and packing measures of typical attractors, we need to specialise to the setting of random self-similar sets and we show again that several interesting and new phenomena can occur when we relax to the setting of random self-affine carpets. The material in this Chapter will be based on a paper which has been accepted for publication by 'Ergodic Theory and Dynamical Systems'.
APA, Harvard, Vancouver, ISO, and other styles
24

Laclau, Charlotte. "Hard and fuzzy block clustering algorithms for high dimensional data." Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCB014.

Full text
Abstract:
Notre capacité grandissante à collecter et stocker des données a fait de l'apprentissage non supervisé un outil indispensable qui permet la découverte de structures et de modèles sous-jacents aux données, sans avoir à \étiqueter les individus manuellement. Parmi les différentes approches proposées pour aborder ce type de problème, le clustering est très certainement le plus répandu. Le clustering suppose que chaque groupe, également appelé cluster, est distribué autour d'un centre défini en fonction des valeurs qu'il prend pour l'ensemble des variables. Cependant, dans certaines applications du monde réel, et notamment dans le cas de données de dimension importante, cette hypothèse peut être invalidée. Aussi, les algorithmes de co-clustering ont-ils été proposés: ils décrivent les groupes d'individus par un ou plusieurs sous-ensembles de variables au regard de leur pertinence. La structure des données finalement obtenue est composée de blocs communément appelés co-clusters. Dans les deux premiers chapitres de cette thèse, nous présentons deux approches de co-clustering permettant de différencier les variables pertinentes du bruit en fonction de leur capacité \`a révéler la structure latente des données, dans un cadre probabiliste d'une part et basée sur la notion de métrique, d'autre part. L'approche probabiliste utilise le principe des modèles de mélanges, et suppose que les variables non pertinentes sont distribuées selon une loi de probabilité dont les paramètres sont indépendants de la partition des données en cluster. L'approche métrique est fondée sur l'utilisation d'une distance adaptative permettant d'affecter à chaque variable un poids définissant sa contribution au co-clustering. D'un point de vue théorique, nous démontrons la convergence des algorithmes proposés en nous appuyant sur le théorème de convergence de Zangwill. Dans les deux chapitres suivants, nous considérons un cas particulier de structure en co-clustering, qui suppose que chaque sous-ensemble d'individus et décrit par un unique sous-ensemble de variables. La réorganisation de la matrice originale selon les partitions obtenues sous cette hypothèse révèle alors une structure de blocks homogènes diagonaux. Comme pour les deux contributions précédentes, nous nous plaçons dans le cadre probabiliste et métrique. L'idée principale des méthodes proposées est d'imposer deux types de contraintes : (1) nous fixons le même nombre de cluster pour les individus et les variables; (2) nous cherchons une structure de la matrice de données d'origine qui possède les valeurs maximales sur sa diagonale (par exemple pour le cas des données binaires, on cherche des blocs diagonaux majoritairement composés de valeurs 1, et de 0 à l’extérieur de la diagonale). Les approches proposées bénéficient des garanties de convergence issues des résultats des chapitres précédents. Enfin, pour chaque chapitre, nous dérivons des algorithmes permettant d'obtenir des partitions dures et floues. Nous évaluons nos contributions sur un large éventail de données simulées et liées a des applications réelles telles que le text mining, dont les données peuvent être binaires ou continues. Ces expérimentations nous permettent également de mettre en avant les avantages et les inconvénients des différentes approches proposées. Pour conclure, nous pensons que cette thèse couvre explicitement une grande majorité des scénarios possibles découlant du co-clustering flou et dur, et peut être vu comme une généralisation de certaines approches de biclustering populaires
With the increasing number of data available, unsupervised learning has become an important tool used to discover underlying patterns without the need to label instances manually. Among different approaches proposed to tackle this problem, clustering is arguably the most popular one. Clustering is usually based on the assumption that each group, also called cluster, is distributed around a center defined in terms of all features while in some real-world applications dealing with high-dimensional data, this assumption may be false. To this end, co-clustering algorithms were proposed to describe clusters by subsets of features that are the most relevant to them. The obtained latent structure of data is composed of blocks usually called co-clusters. In first two chapters, we describe two co-clustering methods that proceed by differentiating the relevance of features calculated with respect to their capability of revealing the latent structure of the data in both probabilistic and distance-based framework. The probabilistic approach uses the mixture model framework where the irrelevant features are assumed to have a different probability distribution that is independent of the co-clustering structure. On the other hand, the distance-based (also called metric-based) approach relied on the adaptive metric where each variable is assigned with its weight that defines its contribution in the resulting co-clustering. From the theoretical point of view, we show the global convergence of the proposed algorithms using Zangwill convergence theorem. In the last two chapters, we consider a special case of co-clustering where contrary to the original setting, each subset of instances is described by a unique subset of features resulting in a diagonal structure of the initial data matrix. Same as for the two first contributions, we consider both probabilistic and metric-based approaches. The main idea of the proposed contributions is to impose two different kinds of constraints: (1) we fix the number of row clusters to the number of column clusters; (2) we seek a structure of the original data matrix that has the maximum values on its diagonal (for instance for binary data, we look for diagonal blocks composed of ones with zeros outside the main diagonal). The proposed approaches enjoy the convergence guarantees derived from the results of the previous chapters. Finally, we present both hard and fuzzy versions of the proposed algorithms. We evaluate our contributions on a wide variety of synthetic and real-world benchmark binary and continuous data sets related to text mining applications and analyze advantages and inconvenients of each approach. To conclude, we believe that this thesis covers explicitly a vast majority of possible scenarios arising in hard and fuzzy co-clustering and can be seen as a generalization of some popular biclustering approaches
APA, Harvard, Vancouver, ISO, and other styles
25

Caby, Théophile. "Extreme value theory for dynamical systems, with applications in climate and neuroscience." Thesis, Toulon, 2019. http://www.theses.fr/2019TOUL0017.

Full text
Abstract:
Tout au long de la thèse, nous discuterons, améliorerons et fournirons un cadre conceptuel dans lequel des méthodes basées sur les propriétés de récurrence de dynamiques chaotiques peuvent être comprises. Nous fournirons également de nouvelles méthodes basées sur l'EVT pour calculer les quantités d'intérêt et présenteronsr de nouveaux indicateurs utiles associés à la dynamique. Nos résultats auront une rigueur mathématique totale, même si l'accent sera mis sur les applications physiques et les calculs numériques, car l'utilisation de telles méthodes se développe rapidement. Nous commencerons par un chapitre introductif à la théorie dynamique des événements extrêmes, dans lequel nous décrirons les principaux résultats de la théorie qui seront utilisés tout au long de la thèse. Après un petit chapitre dans lequel nous introduisons certains objets caractéristiques de la mesure invariante du système, à savoir les dimensions locales et les dimensions généralisées, nous consacrons les chapitres suivants à l'utilisation de EVT pour calculer de telles quantités dimensionnelles. L'une de ces méthodes définit naturellement un nouvel indicateur global sur les propriétés hyperboliques du système. Dans ces chapitres, nous présenterons plusieurs applications numériques des méthodes, à la fois dans des systèmes réels et idéalisés, et étudierons l'influence de différents types de bruit sur ces indicateurs. Nous examinerons ensuite une question d'importance physique liée à l'EVT : les statistiques de visites dans certains sous-ensembles cibles spécifiques de l'espace de phase, en particulier pour les systèmes partiellement aléatoires et bruyants. Les résultats présentés dans cette section sont principalement numériques et hypothétiques, mais révèlent un comportement universel des statistiques de visites. Le huitième chapitre établit la connexion entre plusieurs quantités locales associées à la dynamique et calculées à l'aide d'une quantité finie de données (dimensions locales, temps de frappe, temps de retour) et les dimensions généralisées du système, calculables par les méthodes EVT. Ces relations, énoncées dans le langage de la théorie des grandes déviations (que nous exposerons brièvement), ont de profondes implications physiques et constituent un cadre conceptuel dans lequel la distribution de ces quantités locales calculées peut être comprise. Nous tirons ensuite parti de ces connexions pour concevoir d'autres méthodes permettant de calculer les dimensions généralisées d'un système. Enfin, dans la dernière partie de la thèse, qui est plus expérimentale, nous étendons la théorie dynamique des événements extrêmes à des observables
Throughout the thesis, we will discuss, improve and provide a conceptual framework in which methods based on recurrence properties of chaotic dynamics can be understood. We will also provide new EVT-based methods to compute quantities of interest and introduce new useful indicators associated to the dynamics. Our results will have full mathematical rigor, although emphasis will be placed on physical applications and numerical computations, as the use of such methods is developing rapidly. We will start by an introductory chapter to the dynamical theory of extreme events, in which we will describe the principal results of the theory that will be used throughout the thesis. After a small chapter where we introduce some abjects that are characteristic of the invariant measure of the system, namely local dimensions and generalized dimensions, w1 devote the following chapters to the use of EVT to compute such dimensional quantities. One of these method defines naturally a navel global indicator on the hyperbolic properties of the system. ln these chapters, we will present several numerical applications of the methods, bath in real world and idealized systems, and study the influence of different kinds of noise on these indicators. We will then investigate a matter of physical importanc related to EVT: the statistics of visits in some particular small target subsets of the phase-space, in particular for partly random, noisy systems. The results presented in this section are mostly numerical and conjectural, but reveal some universal behavior of the statistics of visits. The eighth chapter makes the connection betweer several local quantities associated to the dynamics and computed using a finite amount of data (local dimensions, hitting times, return times) and the generalized dimensions of the system, that are computable by EVT methods. These relations, stated in the language of large deviation theory (that we will briefly present), have profound physical implications, and constitute a conceptual framework in which the distribution of such computed local quantities can be understood. We then take advantage of these connections to design further methods to compute the generalized dimensions of a system. Finally, in the last part of the thesis, which is more experimental, we extend the dynamical theory of extreme events to more complex observables, which will allow us to study phenomena evolving over long temporal scales. We will consider the example of firing cascades in a model of neural network. Through this example, we will introduce a navel approach to study such complex systems
APA, Harvard, Vancouver, ISO, and other styles
26

Snigireva, Nina. "Inhomogeneous self-similar sets and measures." Thesis, St Andrews, 2008. http://hdl.handle.net/10023/X682.

Full text
APA, Harvard, Vancouver, ISO, and other styles
27

Atanasov, Risto. "Groups of geometric dimension 2." Diss., Online access via UMI:, 2007.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
28

Wong, Vivian Lola. "MACMAHON'S MASTER THEOREM AND INFINITE DIMENSIONAL MATRIX INVERSION." Master's thesis, University of Central Florida, 2004. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4443.

Full text
Abstract:
MacMahon's Master Theorem is an important result in the theory of algebraic combinatorics. It gives a precise connection between coefficients of certain power series defined by linear relations. We give a complete proof of MacMahon's Master Theorem based on MacMahon's original 1960 proof. We also study a specific infinite dimensional matrix inverse due to C. Krattenthaler.
M.S.
Department of Mathematics
Arts and Sciences
Mathematics
APA, Harvard, Vancouver, ISO, and other styles
29

Jasper, John 1981. "Infinite dimensional versions of the Schur-Horn theorem." Thesis, University of Oregon, 2011. http://hdl.handle.net/1794/11575.

Full text
Abstract:
ix, 99 p.
We characterize the diagonals of four classes of self-adjoint operators on infinite dimensional Hilbert spaces. These results are motivated by the classical Schur-Horn theorem, which characterizes the diagonals of self-adjoint matrices on finite dimensional Hilbert spaces. In Chapters II and III we present some known results. First, we generalize the Schur-Horn theorem to finite rank operators. Next, we state Kadison's theorem, which gives a simple necessary and sufficient condition for a sequence to be the diagonal of a projection. We present a new constructive proof of the sufficiency direction of Kadison's theorem, which is referred to as the Carpenter's Theorem. Our first original Schur-Horn type theorem is presented in Chapter IV. We look at operators with three points in the spectrum and obtain a characterization of the diagonals analogous to Kadison's result. In the final two chapters we investigate a Schur-Horn type problem motivated by a problem in frame theory. In Chapter V we look at the connection between frames and diagonals of locally invertible operators. Finally, in Chapter VI we give a characterization of the diagonals of locally invertible operators, which in turn gives a characterization of the sequences which arise as the norms of frames with specified frame bounds. This dissertation includes previously published co-authored material.
Committee in charge: Marcin Bownik, Chair; N. Christopher Phillips, Member; Yuan Xu, Member; David Levin, Member; Dietrich Belitz, Outside Member
APA, Harvard, Vancouver, ISO, and other styles
30

Gustavsson, Bim. "Representations of Finite-Dimensional Algebras and Gabriel’s Theorem." Thesis, Uppsala universitet, Algebra och geometri, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-395660.

Full text
APA, Harvard, Vancouver, ISO, and other styles
31

Papaioannou, Theodoros. "The moral dimension of Hayek's political theory." Thesis, University of Sussex, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390829.

Full text
Abstract:
This thesis provides an 'immanent' critique of the moral dimension of Hayek's political theory. The concept of morality that Hayek advances is epistemologically founded. That concept is concerned with the recognition and respect of the natural limits of human knowledge and is incompatible with the idea of objective value judgement. The moral dimension of Hayek's theory is based on the methodological implications of his epistemologically founded concept of morality. That dimension consists of the ideas of social spontaneity and cultural evolution and is incompatible with any concept of objective liberal values. The moral dimension of Hayek's theory excludes but also requires substantive politics. The moral exclusion of substantive politics' undermines freedom and equality in catallaxy while, at the same time, it relativises commutative justice and legitimates the minimal state only from the point of view of its legality. Substantive politics is morally required for preserving and promoting institutions such as catallaxy and commutative justice in terms of liberalism. It is argued that the moral exclusion of substantive politics is due to the epistemological premises of Hayek's theory. Those premises form the praxeological presuppositions of social spontaneity and cultural evolution. In terms of them, substantive politics cannot be morally explained. Substantive politics is grounded on a normative/evaluative conception of a social good. That conception depends on critical reason in terms of which objective liberal values can be "recognised and respected. The moral requirement of substantive politics is due to the fact that the process of social spontaneity and cultural evolution cannot by itself be safeguarded against coercion, inequality and injustice.
APA, Harvard, Vancouver, ISO, and other styles
32

Connell, Matt F. "The psychoanalytic dimension of Adorno's critical theory." Thesis, Nottingham Trent University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387533.

Full text
APA, Harvard, Vancouver, ISO, and other styles
33

Fazzi, Marco. "Higher-dimensional field theories from type II supergravity: Théories des champs à haute dimension résultant de la supergravité de type II." Doctoral thesis, Universite Libre de Bruxelles, 2016. https://dipot.ulb.ac.be/dspace/bitstream/2013/232901/4/main.pdf.

Full text
Abstract:
Dans cette thèse, nous présentons des constructions explicites de la correspondance AdS/CFT dans le contexte de la théorie des cordes de type II. Ces constructions sont visées à mieux comprendre aspects de la physique nonperturbative de théories des champs superconformes à d = 6,5,4 dimensions. Dans la première partie de la thèse nous introduisons les systèmes de NS5-Dp-D(p+2)-branes de Hanany-Witten, au moyen desquels on peut construire théories des champs avec 8 supercharges. Quand p = 6, le système de NS5-D6-D8-branes permet de construire théories des champs superconformes à 6 dimensions, caractérisées par des multiplets tenseur, vecteur et hypermultiplets de la superalgèbre chirale N = (1,0). Ces théories sont décrites par des «quivers» linéaires; nous analysons en détails leurs propriétés. Dans le cadre de la correspondance AdS/CFT, une théorie superconforme à (d - 1) dimensions décrit la même physique qu’un vide de la théorie des cordes de type II compactifiée sur un espace-temps Anti-de Sitter à d dimensions (AdSd). Par le biais de la géométrie complexe généralisée nous reformulons les équations qui doivent être résolues pour trouver ces vides AdS. La seconde partie contient les contributions originales. Nous présentons une classification exhaustive des vides de la théorie des cordes de type II compactifiée sur AdS7. En type IIB, il n’y a aucun vide; en type IIA massif, nous construisons une nouvelle classe infinie (et analytique) de vides. L’espace interne est topologiquement une 3-sphere, déformée par la présence de D6 et D8-branes. Les isométries de cet espace réalisent la symétrie R des théories superconformes N = (1,0) à 6 dimensions. Nos vides AdS7 sont les duaux holographiques de ces dernières, et peuvent être obtenus par une limite près de l’horizon des systèmes de NS5-D6-D8-branes. Le second résultat est la construction d’une classe infinie de vides analytiques AdS5 en type IIA massif. L’espace interne est le produit d’une 3-sphere par une surface de Riemann. Les isométries de cet espace réalisent la symétrie R des théories superconformes N = 1 à 4 dimensions, dont nos vides AdS5 sont les duaux holographiques. Nous décrivons une bijection entre ces derniers et les vides AdS7 susmentionnés. L’interprétation holographique indique que les théories N = 1 à 4 dimensions sont obtenues en compactifiant celles N = (1,0) à 6 dimensions sur la même surface de Riemann. Troisièmement, nous réduisons à deux equations différentielles le problème de classification des vides AdS6 en type IIB duaux à théories superconformes N = 1 à 5 dimensions. L’espace interne de ces vides contient une 2-sphere, réalisant la symétrie R des ces dernières.
In this thesis we present explicit constructions of the AdS/CFT correspondence obtained from type II string theory. These constructions are aimed at studying aspects of the nonperturbative physics of 6d, 5d, 4d SCFTs. In the first part we introduce NS5-Dp-D(p+2) Hanany--Witten brane systems, capable of engineering field theories with 8 Q supercharges. In particular, when p=6, the NS5-D6-D8 brane systems are known to engineer 6d SCFT featuring tensor, vector and hypermultiplets of the chiral N=(1,0) superalgebra. These theories can be described by linear quivers. We analyze in detail their properties. In AdS/CFT, the same physics can be equivalently described by a (d-1)-dimensional SCFT and by type II string theory compactified on a d-dimensional AdS space (AdSd), giving rise to a so-called AdSd vacuum. By using techniques derived from generalized complex geometry we reformulate the equations that need to be satisfied in order to find these AdS vacua. The second part of the thesis contains the original contributions. We present a full classification of vacua of type II string theory compactified on AdS7. In type IIB there are no such vacua; in massive type IIA, we construct a new infinite class of (analytic) vacua. The internal space is topologically a three-sphere, deformed by the presence of D6 and D8-branes. The isometries of this space realize the R-symmetry of the 6d (1,0) SCFTs. Our AdS7 vacua are the holographic duals of the latter, and can be obtained via a near-horizon limit of the NS5-D6-D8 brane systems. The second result is the construction of an infinite class of analytic AdS5 vacua of massive IIA. The internal space is a fibration of a (distorted) three-sphere over a Riemann surface. Its isometries realize the R-symmetry of putative 4d N=1 SCFTs, holographically dual to our AdS5 vacua. We describe a universal one-to-one map between the latter and the aforementioned AdS7 vacua. The natural interpretation of this is that the 4d N=1 SCFTs can be obtained by compactifying (in a twisted way) the 6d (1,0) ones on the same Riemann surface. In the third and last part, we reduce to two PDEs the classification problem of AdS6 vacua of type IIB supergravity, which should be the holographic duals to 5d N=1 SCFTs. The latter can be engineered by webs of (p,q)-fivebranes in type IIB string theory. The internal space of the AdS6 vacua is given by a fibration of a round two-sphere over a two-dimensional surface; the isometries of the fibers should realize the R-symmetry of the dual field theories.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished
APA, Harvard, Vancouver, ISO, and other styles
34

Degiovanni, Pascal. "Theories des champs en dimension deux et trois." Paris 6, 1992. http://www.theses.fr/1992PA066115.

Full text
Abstract:
Cette these presente quelques aspects caracteristiques des theories quantiques des champs en dimension 2 et 3. L'axiomatique categorique de la theorie des champs en constitue le langage naturel. Les theories conformes sont analysees et on montre sur l'exemple des theories associees a un groupe fini cyclique comment reconstruire (partiellement) les donnees de moore et seiberg du modele a partir des regles de fusion. En particulier, la determination complete des fonctions de partition invariantes modulaires sur le tore est effectuee. Ensuite, nous montrons que toute theorie topologique rationnelle projective en dimension trois, verifiant deux hypotheses simplificatrices definit une solution des equations de moore et seiberg. Reciproquement, nous montrons que toute solution de ces equations definit une theorie topologique projective rationnelle en dimension trois. Puis nous definissons une classe d'equivalence de theories topologiques bidimensionnelles a partir de chacune de ces theories tridimensionnelles. Cette construction donne une solution complete du modele de wess-zumino-witten jauge. La relation avec la theorie de yang-mills et la theorie de higgs (qui sont egalement resolues dans cette these) est discutee. Finalement, nous replacons tous ces travaux dans une meme perspective autour de la notion de tour modulaire et de ses representations qui sont definies selon les idees de grothendieck
APA, Harvard, Vancouver, ISO, and other styles
35

Schenk, Stefan. "Density functional theory on a lattice." kostenfrei, 2009. http://d-nb.info/998385956/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
36

Zou, Hao. "Low Dimensional Supersymmetric Gauge Theories and Mathematical Applications." Diss., Virginia Tech, 2021. http://hdl.handle.net/10919/103441.

Full text
Abstract:
This thesis studies N=(2,2) gauged linear sigma models (GLSMs) and three-dimensional N=2 Chern-Simons-matter theories and their mathematical applications. After a brief review of GLSMs, we systematically study nonabelian GLSMs for symplectic and orthogonal Grassmannians, following up a proposal in the math community. As consistency checks, we have compared global symmetries, Witten indices, and Calabi-Yau conditions to geometric expectations. We also compute their nonabelian mirrors following the recently developed nonabelian mirror symmetry. In addition, for symplectic Grassmannians, we use the effective twisted superpotential on the Coulomb branch of the GLSM to calculate the ordinary and equivariant quantum cohomology of the space, matching results in the math literature. Then we discuss 3d gauge theories with Chern-Simons terms. We propose a complementary method to derive the quantum K-theory relations of projective spaces and Grassmannians from the corresponding 3d gauge theory with a suitable choice of the Chern-Simons levels. In the derivation, we compare to standard presentations in terms of Schubert cycles, and also propose a new description in terms of shifted Wilson lines, which can be generalized to symplectic Grassmannians. Using this method, we are able to obtain quantum K-theory relations, which match known math results, as well as make predictions.
Doctor of Philosophy
In this thesis, we study two specific models of supersymmetric gauge theories, namely two-dimensional N=(2,2) gauged linear sigma models (GLSMs) and three-dimensional N=2 Chern-Simons-matter theories. These models have played an important role in quantum field theory and string theory for decades, and generated many fruitful results, improving our understanding of Nature by drawing on many branches in mathematics, such as complex differential geometry, intersection theory, quantum cohomology/quantum K-theory, enumerative geometry, and many others. Specifically, this thesis is devoted to studying their applications in quantum cohomology and quantum K-theory. In the first part of this thesis, we systematically study two-dimensional GLSMs for symplectic and orthogonal Grassmannians, generalizing the study for ordinary Grassmannians. By analyzing the Coulomb vacua structure of the GLSMs for symplectic Grassmannians, we are able to obtain the ordinary and equivariant quantum cohomology for these spaces. A similar methodology applies to 3d Chern-Simons-matter theories and quantum K-theory, for which we propose a new description in terms of shifted Wilson lines.
APA, Harvard, Vancouver, ISO, and other styles
37

Hart, Derrick N. "Finite Field Models of Roth's Theorem in One and Two Dimensions." Thesis, Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/11516.

Full text
Abstract:
Recent work on many problems in additive combinatorics, such as Roth's Theorem, has shown the usefulness of first studying the problem in a finite field environment. Using the techniques of Bourgain to give a result in other settings such as general abelian groups, the author gives a walk through, including proof, of Roth's theorem in both the one dimensional and two dimensional cases (it would be more accurate to refer to the two dimensional case as Shkredov's Theorem). In the one dimensional case the argument is at its base Meshulam's but the structure will be essentially Green's. Let Ϝⁿ [subscript p], p ≠ 2 be the finite field of cardinality N = pⁿ. For large N, any subset A ⊂ Ϝⁿ [subscript p] of cardinality ∣A ∣≳ N ∕ log N must contain a triple of the form {x, x + d, x + 2d} for x, d ∈ Ϝⁿ [subscript p], d ≠ 0. In the two dimensional case the argument is Lacey and McClain who made considerable refinements to this argument of Green who was bringing the argument to the finite field case from a paper of Shkredov. Let Ϝ ⁿ ₂ be the finite field of cardinality N = 2ⁿ. For all large N, any subset A⊂ Ϝⁿ ₂ × Ϝⁿ ₂ of cardinality ∣A ∣≳ N ² (log n) − [superscript epsilon], ε <, 1, must contain a corner {(x, y), (x + d, y), (x, y + d)} for x, y, d ∈ Ϝⁿ₂ and d ≠ 0.
APA, Harvard, Vancouver, ISO, and other styles
38

Lancien, Cécilia. "High dimension and symmetries in quantum information theory." Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/386501.

Full text
Abstract:
En unas palabras, el tema de esta tesis se podría resumir como: fenómenos varios en alta (pero finita) dimensión en teoría cuántica de la información. Dicho esto, sin embargo podemos dar algunos detalles de más. Empezando con la observación que la física cuántica ineludiblemente tiene que tratar con objetos de alta dimensión, se pueden seguir esencialmente dos caminos: o intentar reducir su estudio al de otros que tienen dimensión más baja, o intentar comprender qué tipo de comportamiento universal surge precisamente en este régimen. Aquí no elegimos cuál de estas dos posturas hay que adoptar, sino que oscilamos constantemente entre una y la otra. En la primera parte de este manuscrito (Capítulos 5 y 6), nuestro objetivo es reducir al mínimo posible la complejidad de ciertos procesos cuánticos, preservando sus características esenciales. Los dos tipos de procesos que nos interesan son canales cuánticos y medidas cuánticas. En ambos casos, la complejidad de una transformaci ón se cuantifica con el número de operadores necesarios para describir su acción, y la proximidad entre la transformación de origen y su aproximación se define por el hecho de que, cualquiera que sea el estado de entrada, los respectivos estados de salida deben ser suficientemente similares. Proponemos maneras universales de alcanzar nuestras metas de compresión de canales cuánticos y rarefacción de medidas cuánticas (basadas en construcciones aleatorias) y demostramos su optimalidad. En contrapartida, la segunda parte de este manuscrito (Capítulos 7, 8 y 9) se dedica específicamente al análisis de sistemos cuánticos de alta dimensión y sus rasgos típicos. El énfasis se pone sobre sistemos multipartidos y sus propiedades de entrelazamiento. En resumen, establecemos principalmente lo siguiente: cuando las dimensiones de los espacios subyacentes aumentan, es genérico para estados cuánticos multipartidos ser prácticamente indistinguible mediante observaciones locales, y es genérico para relajaciones de la noción de separabilidad ser burdas aproximaciones de ella. Desde un punto de vista técnico, estos resultados se derivan de estimaciones de promedio para supremosa de procesos gaussianos, combinadas con el fenómeno de concentración de la medida. En la tercera parte de este manuscrito (Capítulos 10 y 11), finalmente volvemos a una filosofía de reducción de dimensionalidad. Pero esta vez, nuestra estrategia es utilizar las simetrías inherentes a cada situación particular que consideramos para derivar una simplificación adecuada. Vinculamos de manera cuantitativa simetría por permutación y independencia, lo que nos permite establecer el comportamiento multiplicativo de varias cuantidades que ocurren en teoría cuántica de la información (funciones de soporte de conjuntos de estados, probabilidad de éxito en juegos multi-jugadores no locales etc.). La principal herramienta técnica que desarrollamos con este fin es un resultado de tipo de Finetti muy adaptable.
S'il fallait résumer le sujet de cette thèse en une expression, cela pourrait être quelque chose comme: phénomènes de grande dimension (mais néanmoins finie) en théorie quantique de l'information. Cela étant dit, essayons toutefois de développer brièvement. La physique quantique a inéluctablement afiaire à des objets de grande dimension. Partant de cette observation, il y a, en gros, deux stratégies qui peuvent être adoptées: ou bien essayer de ramener leur étude à celle de situations de plus petite dimension, ou bien essayer de comprendre quels sont les comportements universels précisément susceptibles d'émerger dans ce régime. Nous ne donnons ici notre préférence à aucune de ces deux attitudes, mais au contraire oscillons constamment entre l'une et l'autre. Notre but dans la première partie de ce manuscrit (Chapitres 5 et 6) est de réduire autant que possible la complexité de certains processus quantiques, tout en préservant, évidemment, leurs caractéristiques essentielles. Les deux types de processus auxquels nous nous intéressons sont les canaux quantiques et les mesures quantiques. Dans les deux cas, la complexité d'une transformation est mesurée par le nombre d'opérateurs nécessaires pour décrire son action, tandis que la proximité entre la transformation d'origine et son approximation est définie par le fait que, quel que soit l'état d'entrée, les deux états de sortie doivent être proches l'un de l'autre. Nous proposons des solutions universelles (basées sur des constructions aléatoires) à ces problèmes de compression de canaux quantiques et d'amenuisement de mesures quantiques, et nous prouvons leur optimalité. La deuxième partie de ce manuscrit (Chapitres 7, 8 et 9) est, au contraire, spécifiquement dédiée à l'analyse de systèmes quantiques de grande dimension et certains de leurs traits typiques. L'accent est mis sur les systèmes multi-partites et leurs propriétés ayant un lien avec l'intrication. Les principaux résultats auxquels nous aboutissons peuvent se résumer de la façon suivante: lorsque les dimensions des espaces sous-jacents augmentent, il est générique pour les états quantiques multi-partites d'être à peine distinguables par des observateurs locaux, et il est générique pour les relaxations de la notion de séparabilité d'en être des approximations très grossières. Sur le plan technique, ces assertions sont établies grâce à des estimations moyennes de suprema de processus gaussiens, combinées avec le phénomène de concentration de la mesure. Dans la troisième partie de ce manuscrit (Chapitres 10 et 11), nous revenons pour finir à notre état d'esprit de réduction de dimensionnalité. Cette fois pourtant, la stratégie est plutôt: pour chaque situation donnée, tenter d'utiliser au maximum les symétries qui lui sont inhérentes afin d'obtenir une simplification qui lui soit propre. En reliant de manière quantitative symétrie par permutation et indépendance, nous nous retrouvons en mesure de montrer le comportement multiplicatif de plusieurs quantités apparaissant en théorie quantique de l'information (fonctions de support d'ensembles d'états, probabilités de succès dans des jeux multi-joueurs non locaux etc.). L'outil principal que nous développons dans cette optique est un résultat de type de Finetti particulièrement malléable.
If a one-phrase summary of the subject of this thesis were required, it would be something like: miscellaneous large (but finite) dimensional phenomena in quantum information theory. That said, it could nonetheless be helpful to briefly elaborate. Starting from the observation that quantum physics unavoidably has to deal with high dimensional objects, basically two routes can be taken: either try and reduce their study to that of lower dimensional ones, or try and understand what kind of universal properties might precisely emerge in this regime. We actually do not choose which of these two attitudes to follow here, and rather oscillate between one and the other. In the first part of this manuscript, our aim is to reduce as much as possible the complexity of certain quantum processes, while of course still preserving their essential characteristics. The two types of processes we are interested in are quantum channels and quantum measurements. In both cases, complexity of a transformation is measured by the number of operators needed to describe its action, and proximity of the approximating transformation towards the original one is defined in terms of closeness between the two outputs, whatever the input. We propose universal ways of achieving our quantum channel compression and quantum measurement sparsification goals (based on random constructions) and prove their optimality. Oppositely, the second part of this manuscript is specifically dedicated to the analysis of high dimensional quantum systems and some of their typical features. Stress is put on multipartite systems and on entanglement-related properties of theirs. We essentially establish the following: as the dimensions of the underlying spaces grow, being barely distinguishable by local observers is a generic trait of multipartite quantum states, and being very rough approximations of separability itself is a generic trait of separability relaxations. On the technical side, these statements stem mainly from average estimates for suprema of Gaussian processes, combined with the concentration of measure phenomenon. In the third part of this manuscript, we eventually come back to a more dimensionality reduction state of mind. This time though, the strategy is to make use of the symmetries inherent to each particular situation we are looking at in order to derive a problem-dependent simplification. By quantitatively relating permutation-symmetry and independence, we are able to show the multiplicative behaviour of several quantities showing up in quantum information theory (such as support functions of sets of states, winning probabilities in multi-player non-local games etc.). The main tool we develop for that purpose is an adaptable de Finetti type result.
APA, Harvard, Vancouver, ISO, and other styles
39

Lancien, Cécilia. "High dimension and symmetries in quantum information theory." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1077/document.

Full text
Abstract:
S'il fallait résumer le sujet de cette thèse en une expression, cela pourrait être quelque chose comme: phénomènes de grande dimension (mais néanmoins finie) en théorie quantique de l'information. Cela étant dit, essayons toutefois de développer brièvement. La physique quantique a inéluctablement affaire à des objets de grande dimension. Partant de cette observation, il y a, en gros, deux stratégies qui peuvent être adoptées: ou bien essayer de ramener leur étude à celle de situations de plus petite dimension, ou bien essayer de comprendre quels sont les comportements universels précisément susceptibles d'émerger dans ce régime. Nous ne donnons ici notre préférence à aucune de ces deux attitudes, mais au contraire oscillons constamment entre l'une et l'autre. Notre but dans la première partie de ce manuscrit (Chapitres 5 et 6) est de réduire autant que possible la complexité de certains processus quantiques, tout en préservant, évidemment, leurs caractéristiques essentielles. Les deux types de processus auxquels nous nous intéressons sont les canaux quantiques et les mesures quantiques. Dans les deux cas, la complexité d'une transformation est mesurée par le nombre d'opérateurs nécessaires pour décrire son action, tandis que la proximité entre la transformation d'origine et son approximation est définie par le fait que, quel que soit l'état d'entrée, les deux états de sortie doivent être proches l'un de l'autre. Nous proposons des solutions universelles (basées sur des constructions aléatoires) à ces problèmes de compression de canaux quantiques et d'amenuisement de mesures quantiques, et nous prouvons leur optimalité. La deuxième partie de ce manuscrit (Chapitres 7, 8 et 9) est, au contraire, spécifiquement dédiée à l'analyse de systèmes quantiques de grande dimension et certains de leurs traits typiques. L'accent est mis sur les systèmes multi-partites et leurs propriétés ayant un lien avec l'intrication. Les principaux résultats auxquels nous aboutissons peuvent se résumer de la façon suivante: lorsque les dimensions des espaces sous-jacents augmentent, il est générique pour les états quantiques multi-partites d'être à peine distinguables par des observateurs locaux, et il est générique pour les relaxations de la notion de séparabilité d'en être des approximations très grossières. Sur le plan technique, ces assertions sont établies grâce à des estimations moyennes de suprema de processus gaussiens, combinées avec le phénomène de concentration de la mesure. Dans la troisième partie de ce manuscrit (Chapitres 10 et 11), nous revenons pour finir à notre état d'esprit de réduction de dimensionnalité. Cette fois pourtant, la stratégie est plutôt: pour chaque situation donnée, tenter d'utiliser au maximum les symétries qui lui sont inhérentes afin d'obtenir une simplification qui lui soit propre. En reliant de manière quantitative symétrie par permutation et indépendance, nous nous retrouvons en mesure de montrer le comportement multiplicatif de plusieurs quantités apparaissant en théorie quantique de l'information (fonctions de support d'ensembles d'états, probabilités de succès dans des jeux multi-joueurs non locaux etc.). L'outil principal que nous développons dans cette optique est un résultat de type de Finetti particulièrement malléable
If a one-phrase summary of the subject of this thesis were required, it would be something like: miscellaneous large (but finite) dimensional phenomena in quantum information theory. That said, it could nonetheless be helpful to briefly elaborate. Starting from the observation that quantum physics unavoidably has to deal with high dimensional objects, basically two routes can be taken: either try and reduce their study to that of lower dimensional ones, or try and understand what kind of universal properties might precisely emerge in this regime. We actually do not choose which of these two attitudes to follow here, and rather oscillate between one and the other. In the first part of this manuscript (Chapters 5 and 6), our aim is to reduce as much as possible the complexity of certain quantum processes, while of course still preserving their essential characteristics. The two types of processes we are interested in are quantum channels and quantum measurements. In both cases, complexity of a transformation is measured by the number of operators needed to describe its action, and proximity of the approximating transformation towards the original one is defined in terms of closeness between the two outputs, whatever the input. We propose universal ways of achieving our quantum channel compression and quantum measurement sparsification goals (based on random constructions) and prove their optimality. Oppositely, the second part of this manuscript (Chapters 7, 8 and 9) is specifically dedicated to the analysis of high dimensional quantum systems and some of their typical features. Stress is put on multipartite systems and on entanglement-related properties of theirs. We essentially establish the following: as the dimensions of the underlying spaces grow, being barely distinguishable by local observers is a generic trait of multipartite quantum states, and being very rough approximations of separability itself is a generic trait of separability relaxations. On the technical side, these statements stem mainly from average estimates for suprema of Gaussian processes, combined with the concentration of measure phenomenon. In the third part of this manuscript (Chapters 10 and 11), we eventually come back to a more dimensionality reduction state of mind. This time though, the strategy is to make use of the symmetries inherent to each particular situation we are looking at in order to derive a problem-dependent simplification. By quantitatively relating permutation symmetry and independence, we are able to show the multiplicative behavior of several quantities showing up in quantum information theory (such as support functions of sets of states, winning probabilities in multi-player non-local games etc.). The main tool we develop for that purpose is an adaptable de Finetti type result
APA, Harvard, Vancouver, ISO, and other styles
40

Kagiso, Dintle Nelson. "Dimension theory and multifractal analysis via thermodynamic formalism." Thesis, University of Warwick, 2015. http://wrap.warwick.ac.uk/77523/.

Full text
Abstract:
The thesis deals with dimension theory and ergodic theory. We are interested in applying thermodynamic formalism to give explicit values. Mainly we study dimension of sets with different ergodic averages. An extension to the case of level sets for Gibbs measures of hyperbolic dynamical system are investigated. This leads to very accurate numerical averages.
APA, Harvard, Vancouver, ISO, and other styles
41

Williams, Jeremy M. "Lyapunov Exponents, Entropy and Dimension." Thesis, University of North Texas, 2004. https://digital.library.unt.edu/ark:/67531/metadc4559/.

Full text
Abstract:
We consider diffeomorphisms of a compact Riemann Surface. A development of Oseledec's Multiplicative Ergodic Theorem is given, along with a development of measure theoretic entropy and dimension. The main result, due to L.S. Young, is that for certain diffeomorphisms of a surface, there is a beautiful relationship between these three concepts; namely that the entropy equals dimension times expansion.
APA, Harvard, Vancouver, ISO, and other styles
42

King, James F. "Dimension characteristics for invariant measures." Diss., Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/28788.

Full text
APA, Harvard, Vancouver, ISO, and other styles
43

Shaban, Neil Tamim. "Dimensional regularisation and gauge theories." Thesis, Durham University, 1994. http://etheses.dur.ac.uk/5103/.

Full text
Abstract:
Dimensional regularisation is formulated without using the assumption that f d(^D)k(k(^2))(^n) = 0. Alternative definitions of ϵ(_kλµv) and γ(^5) are also considered. In the reformulated scheme, quadratic divergences are present, in general, in the scalar and gauge boson self-energies, and remain unregularised. The possible cancellation of such divergences is investigated. Phenomenological aspects of unified gauge theories are studied.
APA, Harvard, Vancouver, ISO, and other styles
44

Karat, Edwin Richard 1972. "Topics in field theories in lower dimensions." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/85330.

Full text
APA, Harvard, Vancouver, ISO, and other styles
45

Bonnet, Anna. "Heritability Estimation in High-dimensional Mixed Models : Theory and Applications." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS498/document.

Full text
Abstract:
Nous nous intéressons à desméthodes statistiques pour estimer l'héritabilitéd'un caractère biologique, qui correspond à lapart des variations de ce caractère qui peut êtreattribuée à des facteurs génétiques. Nousproposons dans un premier temps d'étudierl'héritabilité de traits biologiques continus àl'aide de modèles linéaires mixtes parcimonieuxen grande dimension. Nous avons recherché lespropriétés théoriques de l'estimateur du maximumde vraisemblance de l'héritabilité : nousavons montré que cet estimateur était consistantet vérifiait un théorème central limite avec unevariance asymptotique que nous avons calculéeexplicitement. Ce résultat, appuyé par des simulationsnumériques sur des échantillons finis,nous a permis de constater que la variance denotre estimateur était très fortement influencéepar le ratio entre le nombre d'observations et lataille des effets génétiques. Plus précisément,quand le nombre d’observations est faiblecomparé à la taille des effets génétiques (ce quiest très souvent le cas dans les étudesgénétiques), la variance de l’estimateur était trèsgrande. Ce constat a motivé le développementd'une méthode de sélection de variables afin dene garder que les variants génétiques les plusimpliqués dans les variations phénotypiques etd’améliorer la précision des estimations del’héritabilité.La dernière partie de cette thèse est consacrée àl'estimation d'héritabilité de données binaires,dans le but d'étudier la part de facteursgénétiques impliqués dans des maladies complexes.Nous proposons d'étudier les propriétésthéoriques de la méthode développée par Golanet al. (2014) pour des données de cas-contrôleset très efficace en pratique. Nous montronsnotamment la consistance de l’estimateur del’héritabilité proposé par Golan et al. (2014)
We study statistical methods toestimate the heritability of a biological trait,which is the proportion of variations of thistrait that can be explained by genetic factors.First, we propose to study the heritability ofquantitative traits using high-dimensionalsparse linear mixed models. We investigate thetheoretical properties of the maximumlikelihood estimator for the heritability and weshow that it is a consistent estimator and that itsatisfies a central limit theorem with a closedformexpression for the asymptotic variance.This result, supported by an extendednumerical study, shows that the variance of ourestimator is strongly affected by the ratiobetween the number of observations and thesize of the random genetic effects. Moreprecisely, when the number of observations issmall compared to the size of the geneticeffects (which is often the case in geneticstudies), the variance of our estimator is verylarge. This motivated the development of avariable selection method in order to capturethe genetic variants which are involved themost in the phenotypic variations and providemore accurate heritability estimations. Wepropose then a variable selection methodadapted to high dimensional settings and weshow that, depending on the number of geneticvariants actually involved in the phenotypicvariations, called causal variants, it was a goodidea to include or not a variable selection stepbefore estimating heritability.The last part of this thesis is dedicated toheritability estimation for binary data, in orderto study the proportion of genetic factorsinvolved in complex diseases. We propose tostudy the theoretical properties of the methoddeveloped by Golan et al. (2014) for casecontroldata, which is very efficient in practice.Our main result is the proof of the consistencyof their heritability estimator
APA, Harvard, Vancouver, ISO, and other styles
46

Phan, Quang. "Weak factor model in large dimension." Thesis, University of Warwick, 2015. http://wrap.warwick.ac.uk/69442/.

Full text
Abstract:
This thesis presents some extensions to the current literature in high-dimensional static factor models. When the cross-section dimension (represented by N hence-forth) is very large, the standard assumption for each common factor is to have the number of non-zero loadings grow linearly with N . On the other hand, an idiosyncratic error for each component can only be correlated with a finite number of other components in the cross-section. These two assumptions are crucial in standard high-dimensional factor analysis, as they allow us to obtain consistent estimators for the factors, the loadings and the number of factors. However, together they rule out the possibility that we may have some factors that have strictly less than N but still non-negligible number of non-zero loadings, e.g. N for some 0 < < 1 . The existence of these weak factors will decrease the signal-to-noise ratio as now the gap between the systematic and idiosyncratic eigenvalues is more narrow. As the consequence, in such model it is harder to establish the consistency of the factors estimated by sample principle components. Furthermore, the number of factors is even more challenging to identify because most existing methods rely on the large signal-to-noise ratio. In this thesis, I consider a factor model that allows general strength for each factor, i.e. both strong and weak factors can exist. Chapter 1 gives more discussions about the current literature on this and the motivation for my contribution. In Chapter 2, I show that the sample principle components are still the consistent estimators for the factors (up to the spanning space), provided that the factors are not too weak. In addition, I derive the lower bound that the strength of the weakest factor needs to achieve for being consistently estimated. More precisely, what I mean by strength is the order of the number of non-zero loadings of the factor. Chapter 3 presents a novel method to determine the number of factors, which is asymptotically consistent even when the factors are weak. I run extensive Monte Carlo simulations to compare the performance of this method to the two well-known ones, i.e. the class of criteria proposed in Bai and Ng (2002) and the eigenvalue ratio method in Ahn and Horenstein (2013). In Chapter 4 and 5, I show some applications that are based on the work of this thesis. I mainly focus on two issues: selecting the factor models in practice and using factor analysis to compute the large static covariance matrix.
APA, Harvard, Vancouver, ISO, and other styles
47

Yoon, Seok Ho. "Explicit class field theory : one dimensional and higher dimensional." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/50367/.

Full text
Abstract:
This thesis investigates class field theory for one dimensional fields and higher dimensional fields. For one dimensional fields we cover the cases of local fields and global fields of positive characteristic. For higher dimensional fields we study the case of higher local fields of positive characteristic. The main content of the thesis is divided into two parts. The first part solves several problems directly related to Neukirch's axiomatic class field theory method. We first prove the famous Hilbert 90 Theorem in the case of tamely ramified extensions of local fields in an explicit way. This approach can be of use in understanding the role of the ring structure as opposed to the role of multiplication only in local class field theory. Next, we prove that for every local field, its `class field theory' is unique. Lastly, we establish the Neukirch axiom for global fields of positive characteristic, which leads to a new approach to class field theory for such fields, an approach that has not appeared in the previous literature. There are two main successful directions in higher local class field theory, one by Kato and another by Fesenko. While Kato used a technical cohomological method, Fesenko generalised the Neukirch method and gave the first proof of the existence theorem. In the second part of the thesis we deal with the third method in class field theory that works in positive characteristic only, the Kawada-Satake method. We generalise the classical Kawada-Satake method to higher local fields of positive characteristic. We correct substantial mistakes in a paper of Parshin on such class field theory. We develop the first complete presentation of the theory based on the generalised Kawada-Satake method using advanced properties of topological Milnor K-groups. These advanced properties include Fesenko's theorem about relations of topological and algebraic properties of Milnor K-groups.
APA, Harvard, Vancouver, ISO, and other styles
48

Ohki, Hiroshi. "Chiral four dimensional field theory from superstring and higher dimensional super Yang-Mills theory." 京都大学 (Kyoto University), 2010. http://hdl.handle.net/2433/120647.

Full text
APA, Harvard, Vancouver, ISO, and other styles
49

Hurth, Tobias. "Limit theorems for a one-dimensional system with random switchings." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37201.

Full text
Abstract:
We consider a simple one-dimensional random dynamical system with two driving vector fields and random switchings between them. We show that this system satisfies a one force - one solution principle and compute its unique invariant density explicitly. We study the limiting behavior of the invariant density as the switching rate approaches zero and infinity and derive analogues of classical probabilistic results such as the central limit theorem and large deviations principle.
APA, Harvard, Vancouver, ISO, and other styles
50

Gao, Yuan. "Dimension Identification in Data Warehouse Based on Activity Theory." Thesis, Växjö University, School of Mathematics and Systems Engineering, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:vxu:diva-898.

Full text
Abstract:

Nowadays, business intelligence techniques are applied more and more often in different settings including corporations and organizations both in the private and public sector. It is really a broad field which can assist business people to realize the state of their organization and make profitable decisions.

In this thesis, I will focus on one of its components, data warehouse, by proposing activity theory as the method to solve the dimension identification problem in data warehouse. Under the background of project IMIS and the involved personnel, who determine the dimension, firstly I study how to use the ER method, “bottom up” method, and activity theory method to identify the dimension in data warehouse, and some relevant knowledge about the three methods. Then, we apply the three methods to identify the dimension. After that, I evaluate the dimension identification results of the three methods according to the feedback from the healthcare organization to get their veracity and integrality. Finally, based on the results of my efforts, I arrive to the conclusion that the activity theory method can be applied to identify the dimension in data warehouse, and with the comparison to the other two traditional methods (ER model and “bottom up”), the activity theory method is more easy and natural to identify the dimension of a dimensional model.

APA, Harvard, Vancouver, ISO, and other styles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography