IME - Instituto de Matemática e Estatística
URI Permanente desta comunidade
Navegar
Navegando IME - Instituto de Matemática e Estatística por Por Área do CNPQ "CNPQ::CIENCIAS EXATAS E DA TERRA::MATEMATICA"
Agora exibindo 1 - 13 de 13
Resultados por página
Opções de Ordenação
Item Convergência do Método do Ponto Proximal para Funções que Satisfazem a Desigualdade de Łojasiewicz(Universidade Federal de Goiás, 2012-06-27) AMARAL, José Henrique Salazar do; BENTO, Glaydston de Carvalho; http://lattes.cnpq.br/1089906772427394This paper presents an analysis of convergence of the proximal point method for functions that satisfy the inequality of Lojasiewicz.Item Derivaçao de uma Equação Diferencial Parcial Não-Linear na Propagação de Frentes de Reação em Química(Universidade Federal de Goiás, 2008-08-29) CARDOSO FILHO, João Lopes; ALARCON, Eduardo Arbieto; http://lattes.cnpq.br/5960048699820842In this dissertação we deducted a nonlinear evolution equations which model vertical propagation of chemical reaction fronts. We establish which the initial value problem ∂tu - ∂²x u - ½(∂xu)² - µ(1-∂²x) - ½u = 0, x Є [-π, π], t > 0 u(.,0) = ø, 2 π - periódica it is a the Cauchy problem locally well-posed.Item Difeomorfismos conformes que preservam o tensor de Ricci em variedades semi-riemannianas(Universidade Federal de Goiás, 2011-01-28) CARVALHO, Fernando Soares de; PINA, Romildo da Silva; http://lattes.cnpq.br/2675728978857991; SILVA, Rosângela Maria da; http://lattes.cnpq.br/0085316338495571NOTE: Because some programs do not copy symbols, formulas, etc... to view the summary and the contents of the file, click on PDF - dissertation on the bottom of the screen.Item Convergência local do método de Newton inexato e suas variações do ponto de vista do princípio majorante de kantorovich(Universidade Federal de Goiás, 2007-12-14) GONAÇALVES, Max Leandro Nobre; FERREIRA, Orizon Pereira; lattes.cnpq.br/0201145506453251The search for solutions of nonlinear equations in the Euclidean spaces is object of interest in some areas of science and engineerings. Due the speed of convergence and computational efficiency, the inexact Newton method and its variations have been suficiently used to obtain solutions of these equations. In this dissertation we present a local analysis of convergence of the inexact Newton method and some of its variations, more specifically the inexact Newton-like method and the inexact modified Newton method. This analysis has the disadvantage to demand the previous knowledge of a zero of the operator in consideration and the hypotheses on the behavior of the operator at this zero, but on the other hand it supplies to information on the convergence rate and convergence radius.Item Superfícies mínimas com curvatura constante nas formas espaciais 4-dimensionais(Universidade Federal de Goiás, 2011-05-13) HIEDA, Lidiane Mayumi; PINA, Romildo da Silva; http://lattes.cnpq.br/2675728978857991This work was based on papers On Compact Minimal Surfaces with non-negative Gaussian Curvature in a Space of Constant Curvature: I and Minimal Surfaces with Constant Curvature in 4-dimensional Space Forms, by Katsuei Kenmotsu, consisting in the classification of minimal surfaces with constant Gaussian curvature K in a 4-dimensional space form without any global assumption. We will show that an isometric minimal immersion x: M2(K) → M4(c), where c is sectional curvature, is either totally geodesic, or locally Clifford Torus, or locally a Veronese surface. As a corollary, we have that there is not isometric minimal immersions with constant negative Gaussian curvature into unit sphere S4(1) even locally.Item Sólitons de Ricci Shrinking em variedades Riemannianas completas(Universidade Federal de Goiás, 2011-09-02) LEANDRO NETO, Benedito; PINA, Romildo da Silva; http://lattes.cnpq.br/2675728978857991In this work, we started with an historical study of Ricci Solitons showing that they, often, arise as a auto-similar solution for the Ricci flow. It was demonstrated, then, some basic concepts of Riemannian Geometry and a formal definition of a Ricci Solitons. To conclude the work, it was presented a study analysis of the [6] article, establishing , among other results, two theorems: the first one, an estimation for the potential function of a Gradient Shrinking Ricci Solitons, complete non-compact, and, the second one, an estimation for the volume of a Gradient Shrinking Ricci Solitons, complete non-compact.Item Sobre Centralizadores de Automorfismos Coprimos em Grupos Profinitos e Álgebras de Lie(Universidade Federal de Goiás, 2011-06-27) LIMA, Márcio Dias de; SILVA, Jhone Caldeira; http://lattes.cnpq.br/6848751340618892; LIMA, Aline de Souza; http://lattes.cnpq.br/1518865173435209A be an elementary abelian group of order q2, where q a prime number. In this paper we will study the influence of centering on the structure of automorphism groups profinitos in this sense if A acting as a coprime group of automorphisms on a group profinito G and CG(a) is periodic for each a 2 A#, then we will show that G is locally finite. It will be demonstrated also the case where A acts as a group of automorphisms of a group pro-p of GItem Movimentos sob atração focal em campos vetoriais planares(Universidade Federal de Goiás, 2008-08-29) MARTINS, Tiberio Bittencourt de Oliveira; GARCIA, Ronaldo Alves; http://lattes.cnpq.br/5680428710939826In this work, we develop the article On the motion under focal attraction in a rotating medium , of J. Sotomayor, which deals with a bidimensional differential system that model the following Biological problem: in a shallow recipient with circular section, with liquid in, spinning with angular speed ω, there are platyhelminthes, flatworms organisms, they are attracted by a fix lighting point near of the border of the recipient and they swim with a speed v in the direction of the this point. The problem is to show that there exists an equilibrium point where platyhelminthes go to cluster by the time passing. It s analyzed the dynamic of the model: existence of critical points and stability of the system and bifurcations. We analyzed three modifications of this system too. In the last part, it s discussed a criterium for non existence of periodic orbits of a planar vector fields in a simply connected region.Item Uma melhora das cotas de Feng-Rao e de Miura para a distância mínima de códigos definidos sobre uma variedade afim(Universidade Federal de Goiás, 2007-12-18) MESQUITA, Aline Mota de; RODRIGUES, Paulo Henrique de Azevedo; lattes.cnpq.br/8910130626123426In this work we present some linear codes and we discuss about parameters of cyclic codes families that lead to the characterization of the Goppa codes, which we describe minimum distance bounds when it is given for an affine variety. When this code is defined like this, we say that it is an improved geometric Goppa code. The first bounds mentioned in this work was given by Feng and Rao in [6] (Feng-Rao bound), later improved by Miura in [18],[19] (weakly Feng-Rao bound), that in its turn has been improved by G. Salazar, D. Dunn and S. B. Graham in [22] (advisory bound and strong advisory estimate). This work was based in this last article. We finishing the dissertation showing families of codes for which we verified the veracity of the improvement of bounds.Item Desigualdades universais para autovalores do operador poli-harmônico(Universidade Federal de Goiás, 2012-03-09) PEREIRA, Rosane Gomes; ADRIANO, Levi Rosa; http://lattes.cnpq.br/3206466156270217In this work, we study eigenvalues of polyharmonic operators on compact Riemannian manifolds with boundary (possibly empty). Here, we bring in a universal inequality for the eigenvalues of the polyharmonic operator on compact domains in an Euclidean space Rn. This inequality controls the kth eigenvalue by the lower eigenvalues, independently of the particular geometry of the domain. Besides, a inequality we present covers the important Yang inequality on eigenvalues of the Dirichlet Laplacian. Finally, we introduce universal inequalities for eigenvalues of polyharmonic operator on compact domains in a unit n-sphere Sn. NOTE: Programs do not copy or copy errors with certain symbols, formulas, formatting, etc ..., n of Rn and Sn are overwritten. View all content by clicking pdf - dissertation at the bottom of the screen.Item Superfícies Mínimas em H3 e H2 x R(Universidade Federal de Goiás, 2008-02-20) RUYS, Wesley da Silva; CORRO, Armando Mauro Vasquez; http://lattes.cnpq.br/4498595305431615In this work we study some results from the article of Mercuri, F., Piu, P., Montaldo, S; Weierstrass Representation Formula for Minimal Surfaces in H3 and H2 x R. Therefore, we do a study of the minimal surfaces simply connected in three-dimensional Riemaniann manifold. Furthermore, searching for to determine the necessary conditions to find minimal surfaces in these spaces. Moreover, to give examples of the surfaces in the three-dimensional Heisenberg group and in the product of the hyperbolic with the real line.Item Hipersuperfacies Conformemente Planas no Espaço Euclidiano R4(Universidade Federal de Goiás, 2008-03-28) SOUSA, Marcio Lemes de; PINA, Romildo da Silva; http://lattes.cnpq.br/2675728978857991In this work we develop the article "Conformally Flat Hypersurfaces in Euclidean 4-space II", of Suyama, where is presented the study on conformally °at hypersurfaces in the Euclidean 4-spaces R4. From a surface with constant Gaussian curvature positive or negative in either Euclidean 3-space R3 or the standard 3-sphere S3, we constructed a family of conformally °at hypersurfaces in R4, with three distinct principal curvaturesItem Classificação das superfícies de revolução tipo Delaunay completas(Universidade Federal de Goiás, 2008-05-30) SOUZA, Luiz Gustavo Alves de; PINA, Romildo da Silva; http://lattes.cnpq.br/2675728978857991In this dissertation we have studied the articles The Surfaces of Delaunay, by James Eells, and Classi¯cation des Surfaces de Type Delaunay, by Ricardo Sa Earp and Eric Toubiana. Based on the ¯rst work we have classi¯ed the surfaces of revolution of constant mean curvature known as surfaces of Delaunay. By using the second one we have looked at special surfaces of Weingarten, whose mean and gaussian curvatures satis¯es the relation H = f(H2 ¡ K); where f is an elliptic function of class C1. We have classi¯ed the complete surfaces of revolution, that satis¯es the Weingarten relation. They are known as surfaces of Delaunay Type