• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 700
  • 332
  • 91
  • 70
  • 39
  • 27
  • 18
  • 16
  • 14
  • 13
  • 11
  • 10
  • 10
  • 8
  • 5
  • Tagged with
  • 1588
  • 322
  • 282
  • 272
  • 150
  • 141
  • 121
  • 113
  • 102
  • 96
  • 95
  • 90
  • 89
  • 87
  • 86
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
351

On unicity problems of meromorphic mappings of Cn into PN(C) and the ramification of the Gauss maps of complete minimal surfaces / Problèmes d'unicité pour des applications méromorphes de Cn dans CPN et ramification de l'application de Gauss pour des surfaces minimales complètes

Ha, Pham Hoang 03 May 2013 (has links)
En 1975 H. Fujimoto a généralisé les résultats d’unicité pour des fonctions holomorphes dus à Nevanlinna pour des applications méromorphes de Cn dans CPN. Il a démontré que pour deux applications méromorphes non linéairement dégénérées f et g de Cn dans CPN, si elles ont les mêmes images réciproques, comptées avec leurs multiplicités, par rapport à (3N + 2) hyperplans de CPN en position générale, alors f g. Depuis, ce problème a été étudié d’une manière intensive par H. Fujimoto, W. Stoll, L. Smiley, M. Ru, G. Dethloff-T.V.Tan, D.D.Thai-S.D.Quang, Chen-Yan et d’autres auteurs. En parallèle avec le développement de la théorie de Nevanlinna, la théorie de distribution des valeurs de l’application de Gauss des surfaces minimales dans Rm a été étudiée d’une manière intensive par R.Osserman, S.S. Chern, F. Xavier, H. Fujimoto, S.J. Kao, M. Ru et d’autres auteurs. Dans cette thèse, nous avons continué d’étudier ces problèmes. Nous avons obtenu les résultats principaux suivants: +) Théorèmes d’unicité avec multiplicités tronquées des applications méromorphes de Cn dans CPN ayant les mêmes images réciproques par rapport è (2N + 2) hyperplans de CPN. +) Théorèmes d’unicité avec multiplicités tronquées des applications méromorphes de Cn dans CPN ayant des cibles mobiles et un ensemble d’identité petit. +) Théorèmes d’unicité avec multiplicités tronquées des applications méromorphes de Cn dans CPN ayant des cibles fixes ou mobiles et satisfaisant des conditions sur les dérivées. +) Théorèmes de ramification de l’application de Gauss de certaines classes de surfaces minimales complètes dans Rm (m = 3,4). / In 1975, H. Fujimoto generalized Nevanlinna’s known results for meromorphic fonctions to the case of meromorphic mappings of Cn into PN(C). He proved that for two linearly nondegenerate meromorphic mappings f and g of C into PN(C). if they have the saine inverse images counted with multiplicities for 3N + 2 hyperplanes in general position in PN(C) then f = g. After that, this problem has been studied intensively by a number of mathematicans as H. Fujimoto, W. Stoll, L. Smiley, M. Ru, G. Dethloff - T. V. Tan, D. D. Thai - S. D. Quang, Chen-Yan and so on. Parallel to the development of Nevanlinna theory, the value distribution theory of the Gauss map of minimal surfaces immersed in Rm vas studied by many mathematicans as R. Osserman, S.S. Chern, F. Xavier, H. Fujimoto, S. J. Kao, M. Ru and many other mathematicans. In this thesis, we continuous studing some problems on these directions. The main goals of the thesis are followings. • Unicity theorems with truncated multiplicities of meromorphic mappings of Cn into PN(C) sharing 2N + 2 fixed hyperplanes.• Unicity theorems with truncated multiplicities of meromorphic mappings of Cn into PN(C) for moving targets, and a small set of identity.
352

[en] THE AMBROSETTI-PRODI THEOREM FOR LIPSCHITZ NONLINEARITIES / [pt] O TEOREMA DE AMBROSETTI E PRODI PARA NÃO LINEARIDADES LIPSCHITZ

ANDRE ZACCUR UCHOA CAVALCANTI 06 September 2012 (has links)
[pt] O estudo de equaçõe semi-lineares do tipo Ambrosetti-Prodi frequentemente usa regularidade da não linearidade. Nesse texto, consideramos nãoo linearidades Lipschitz. Os argumentos geométricos baseados em teoremas de função implícita são substituidos pelo uso de contrações adequadas. / [en] The study of semi-linear equations of Ambrosetti-Prodi type frequently makes use of some smoothness of the nonlinearity. In this text, we consider Lipschitz nonlinearities. The geometric arguments based on implicit functions thoerems are replaced by appropriate contractive mappings.
353

Um estudo sobre teoria dos grafos e o teorema das quatro cores / A study on graph theory and the four color theorem

Lima, Carlos Laercio Gomes de 04 April 2016 (has links)
Neste trabalho estudamos um pouco de Teoria dos Grafos, abordando diversas definições e teoremas interessantes. Apresentamos o Teorema das Quatro Cores, desde o surgimento do problema com Francis Guthrie. Analisamos a demonstração do teorema realizada por Alfred Bray Kempe e sua refutação através do contraexemplo de Percy John Heawood. Analisamos também a demonstração do Teorema das Cinco Cores de Percy John Heawood. Porém, apresentamos a primeira demonstração válida do Teorema das Quatro Cores, como sua particularidade de ter sido feita com o auxílio de um computador. O trabalho é concluído com uma análise sobre os benefícios que o conhecimento de Teoria dos Grafos pode render aos alunos do Ensino Básico, e como professor o pode trabalhar este assunto em sala de aula, inclusive abordando o problema de coloração de mapas. / In this paper we study Graph Theory, addressing various definitions and interesting theorems. We present the Four Color Theorem, since the origin of the problem with Francis Guthrie. We analyze the proof of the theorem presented by Alfred Bray Kempe, and its refutation by Percy John Heawood counter-example. We also analyze the Percy John Heawood demonstration of the Five Color Theorem. Finally, we present the first valid proof of the Four Colors Theorem, with its peculiarity of having been done with the aid of a computer. We conclude with an analysis of the beneficial that the knowledge of Graph Theory can render students of Basic Education, and how a teacher can work this topic in the classroom, including addressing the problem of map coloring.
354

Additive higher representation theory

Klein, Florian January 2014 (has links)
This thesis is devoted to the study of higher representation theory as introduced in [Rou4]. As this theory is in its early days, it is essential to seek out modules that can rightfully be named building blocks and allow one to express as much of the structure of arbitrary modules as possible in their terms. We contribute towards this undertaking in the case of additive higher representation theory. Inspiration is drawn from Soergel bimodules which categorify the Hecke algebra. We introduce functorially cyclic modules as well as (strongly) universal cell modules. Examples include the minimal categorifications of [Rou4]. Properties of such modules are discussed and universal properties in terms of representable 2-functors are established. This leads to constructions and classifications in terms of split Frobenius objects, using a new variant of the Barr-Beck theorem for additive categories. Furthermore, we encounter a new class of modules so called coinvariant modules which arise from automorphism group actions. We also construct canonical cofiltrations and demonstrate why the Jordan-Hölder theory of [Rou4] does not readily generalise. Throughout, we comment on the succession [MaMi1]-[MaMi5] that tackles the same questions, however arrives at different conclusions. As applications, we first show that the 2-category of singular Soergel bimodules of [Wi2] arises naturally within the additive higher representation theory of Soergel bimodules. Second, we establish (weak) equivalences between certain associated universal cell modules together with a categorification of cell module homomorphisms of the Hecke algebra. Third, we show that singular Soergel bimodules constructed with a faithful representation categorify the Schur algebroid, generalising the main result of [Li]. Fourth given a group and a subgroup, we recover the additive monoidal category of representations of the subgroup from the corresponding category for the group without invoking Tannakian formalism.
355

Introduction to differential geometry of plane curves / IntroduÃÃo à geometria diferencial das curvas planas

Felipe D'Angelo Holanda 24 July 2015 (has links)
CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / A intenÃÃo desse trabalho serà de abordar de forma bÃsica e introdutÃria o estudo da Geometria Diferencial, que por sua vez tem seus estudos iniciados com as Curvas Planas. Serà necessÃrio um conhecimento de CÃlculo Diferencial, Integral e Geometria AnalÃtica para melhor compreensÃo desse trabalho, pois como seu prÃprio nome nos transparece Geometria Diferencial vem de uma junÃÃo do estudo da Geometria envolvendo CÃlculo. Assim abordaremos subtemas como curvas suaves, vetor tangente, comprimento de arco passando por fÃrmulas de Frenet, curvas evolutas e involutas e finalizaremos com alguns teoremas importantes, como o teorema fundamental das curvas planas, teorema de Jordan e o teorema dos quatro vÃrtices. O que, basicamente representa, o capÃtulo 1, 4 e 6 do livro IntroduÃÃo Ãs Curvas Planas de HilÃrio Alencar e Walcy Santos. / The intention of this work is to address in basic form and introductory study of Differential Geometry, which in turn has started his studies with Planas curves. It will require a knowledge of Differential Calculus, Integral and Analytic Geometry for better understanding of this work, because as its name says in Differential Geometry comes from the joint study of geometry involving Calculation. So we discuss sub-themes as smooth curves, tangent vector, arc length through formulas of Frenet, evolutas curves and involute and conclude with some important theorems, as the fundamental theorem of plane curves, Jordan 's theorem and the theorem of four vertices. What basically is, Chapter 1, 4 and 6 of the book Introduction to Plane Curves HilÃrio Alencar and Walcy Santos.
356

Poliedros e o Teorema de Euler / Polyhedron and Euler's Theorem

Parreira, José Roberto Penachia 21 March 2014 (has links)
Submitted by Erika Demachki (erikademachki@gmail.com) on 2014-08-29T20:47:14Z No. of bitstreams: 2 Poliedros_E_Teorema_de_Euler.pdf: 4810573 bytes, checksum: f1f57ad45cfd7dc575fe3c3e963b24c6 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-08-29T20:47:14Z (GMT). No. of bitstreams: 2 Poliedros_E_Teorema_de_Euler.pdf: 4810573 bytes, checksum: f1f57ad45cfd7dc575fe3c3e963b24c6 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-03-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This work aims is to demonstrate the Euler's Theorem for polyhedra, given by the equation V 􀀀 A + F = 2, where V; A and F are the numbers of vertices, edges and faces, respectively, the polyhedron. A historical survey of the main characters who contributed to the theme was elaborated. De nitions and properties of polygons and polyhedra were given. The statements were constructed in three distinct ways. The rst by Cauchy, commented by Professor Elon Lages Lima. This statement is valid for any polyhedron homeomorphic to a sphere and has the path planning of the polyhedron withdrawing one of its faces. The second statement was prepared by the professor Zoroastro Azambuja Filho, valid for any convex polyhedron, and its path projection of the polyhedron on a plane and comparison of the internal angles of polygons with projection angles of the polygon faces. The third statements was presented by Legendre, also valid for any convex polyhedron, and its path in the projection of a spherical polyhedron surface. We use the Girard's Formula, the sum of the interior angles of a spherical triangle, to complete the demonstration. This work also suggests methods of applying the proof of Euler's Theorem in the classroom for high school students, and resolution of vestibular exercises involving the subject. / Este trabalho tem por objetivo a demonstra c~ao do Teorema de Euler para poliedros, dado pela equa ção V 􀀀 A + F = 2, onde V; A e F são os n úmeros de v értices, arestas e faces, respectivamente, do poliedro. Foi elaborada uma pesquisa hist orica dos principais personagens que contribuiram para o tema. Foram dadas de ni ções e propriedades de pol ígonos e poliedros. As demonstra ções foram constru ídas em três caminhos distintos. A primeira por Cauchy, comentada pelo professor Elon Lages Lima. Esta demonstra ção é v álida para qualquer poliedro homeomorfo a uma esfera e tem como caminho a plani fica ção do poliedro retirando-se uma de suas faces. A segunda demonstra c~ao foi elaborada pelo professor Zoroastro Azambuja Filho, v álida para qualquer poliedro convexo e tem como caminho a proje ção do poliedro num plano e a compara c~ao dos ângulos internos dos pol ígonos da proje ção com os ângulos dos pol gonos das faces. A terceira demonstra c~ao foi apresentada por Legendre, tamb ém v álida para qualquer poliedro convexo e tem como caminho a projeção do poliedro em uma superf ície esf érica. Utiliza-se a F ormula de Girard, da soma dos ângulos internos de um tri^angulo esf érico, para concluir a demonstra ção. Este trabalho tamb ém sugere metodologias de aplica ção da demonstração do Teorema de Euler em sala de aula, para alunos do Ensino M édio, e resolu ção de exercí cios de vestibulares envolvendo o tema.
357

Baire category theorem

Bergman, Ivar January 2009 (has links)
<p>In this thesis we give an exposition of the notion of <em>category </em>and the <em>Baire category theorem </em>as a set theoretical method for proving existence. The category method was introduced by René Baire to describe the functions that can be represented by a limit of a sequence of continuous real functions. Baire used the term <em>functions of the first class </em>to denote these functions.</p><p>The usage of the Baire category theorem and the category method will be illustrated by some of its numerous applications in real and functional analysis. Since the usefulness, and generality, of the category method becomes fully apparent in Banach spaces, the applications provided have been restricted to these spaces.</p><p>To some extent, basic concepts of metric topology will be revised, as the Baire category theorem is formulated and proved by these concepts. In addition to the Baire category theorem, we will give proof of equivalence between different versions of the theorem.</p><p>Explicit examples, of first class functions will be presented, and we shall state a theorem, due to Baire, providing a necessary condition on the set of points of continuity for any function of the first class.</p><p> </p>
358

Algebraic certificates for Budan's theorem

Bembé, Daniel 02 August 2011 (has links) (PDF)
In this work we present two algebraic certificates for Budan's theorem. Budan's theorem claims the following. Let R be an ordered field, f in R[X] of degree n and a,b in R with a
359

A-optimal designs for weighted polynomial regression

Su, Yang-Chan 05 July 2005 (has links)
This paper is concerned with the problem of constructing A-optimal design for polynomial regression with analytic weight function on the interval [m-a,m+a]. It is shown that the structure of the optimal design depends on a and weight function only, as a close to 0. Moreover, if the weight function is an analytic function a, then a scaled version of optimal support points and weights is analytic functions of a at $a=0$. We make use of a Taylor expansion which coefficients can be determined recursively, for calculating the A-optimal designs.
360

Ds-optimal designs for weighted polynomial regression

Mao, Chiang-Yuan 21 June 2007 (has links)
This paper is devoted to studying the problem of constructing Ds-optimal design for d-th degree polynomial regression with analytic weight function on the interval [m-a,m+a],m,a in R. It is demonstrated that the structure of the optimal design depends on d, a and weight function only, as a close to 0. Moreover, the Taylor polynomials of the scaled versions of the optimal support points and weights can be computed via a recursive formula.

Page generated in 0.038 seconds