In this paper, the study of k-fold branched coverings for which the branch set is a stratified set is considered. First of all, the existence of universal k-fold branched coverings over CW-complexes with stratified branch set is proved using Brown's Representability Theorem. Next, an explicit construction of universal k-fold branched coverings over manifolds is given. Finally, some homotopy and homology groups are computed for some specific examples of Universal k-fold branched coverings.

In this paper, we consider decompositions of the complete graph on v vertices into 4-cycles with a pendant edge. In part, we will consider decompositions which admit automorphisms consisting of: (1) a single cycle of length v, (2) f fixed points and a cycle of length v − f, or (3) two disjoint cycles. The purpose of this thesis is to give necessary and sufficient conditions for the existence of cyclic, f-cyclic, and bicyclic Q-decompositions of Kv.

There are four orientations of cycles on four vertices. Necessary and sufficient conditions are given for covering complete directed digraphs Dv, packing and covering complete bipartite digraphs, Dm,n, and packing and covering the complete digraph on v vertices with hole of size w, D(v,w), with three of the orientations of a 4-cycle, including C4, X, and Y.

The set cover problem is a well studied problem in computer science. The problem cannot be approximated to better than an log n-factor in polynomial time unless P = NP and has an O(log n)-factor approximation algorithm. We consider several special cases of the set cover problem in which geometry plays a key role. With geometric structure introduced to the problem, it may be possible to construct approximation algorithms with approximation ratios asymptotically better than log n. The first problem we consider is the decomposing coverings problem. Here, we consider a combinatorial problem: given a collection of points in the plane and a collection of objects in the plane such that each point is contained in at least k objects, partition the objects into as many sets as possible so that each set covers all of the points. We show that if the objects are translates of a convex polygon, then it is possible to partition the translates into Ω(k) covers. The second problem we consider is the planar sensor cover problem. This problem is a generalization of the decomposing coverings problem. We are given a collection of points in the plane and a collection of objects in the plane. Each of the objects can be thought of as a sensor. The sensors have a duration which can be thought of as the battery life of the sensor. The planar sensor cover problem is to schedule a start time to each of the sensors so that the points are covered by a sensor for as long as possible. We give a constant factor approximation for this problem. The key contribution to this result is a constant factor approximation to a one-dimensional version of the problem called the restricted strip cover (RSC) problem. Our result for RSC improves upon the previous best O(log log log n)-approximation, and our result for the planar sensor cover problem improves upon the previous best O(log n)-approximation. The next problem we consider is the metric clustering to minimize the sum of radii problem. Here, we are given an n-point metric (P,d) and an integer k > 0. We are interested in covering the points in P with at most k balls so that the sum of the radii of the balls is minimized. We give a randomized algorithm which solves the problem exactly in nO(log n log Δ) time, where Δ is the ratio of the maximum interpoint distance to the minimum interpoint distance. We also show that the problem is NP-hard, even in metrics induced by weighted planar graphs and when the metric has constant doubling dimension. The last problem we consider is the minimum dominating set problem for disk graphs. In this problem, we are given a set of disks in the plane, and we want to choose a minimum-cardinality subset of disks such that every disk is either in the set or intersects a disk in the set. For any ε > 0, we show that a simple local search algorithm is a (1+ ε)-approximation for the problem which improves upon the previous best O(log n)-approximation algorithm.

No description available.

Laminate flooring manufacturers have received negative feedback from customers on the sound quality of laminate flooring installations. Customers express a preference for the sound of traditional hardwood floors over that of laminate flooring composites. Consumers notice a difference between the sounds created by a footfall between laminate flooring and hardwood flooring. They perceive the laminate flooring sound of a footfall to be annoying and associate it to the flooring being of a lower quality. No objective test procedure exists to validate the marketing claims of the performance of these products. The objective of the work in this thesis is to develop a test method that evaluates the human perception of the sound quality of footfall noise on laminate flooring composites.

Made available in DSpace on 2014-06-11T19:24:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-08-14Bitstream added on 2014-06-13T18:20:18Z : No. of bitstreams: 1 dahrouj_ls_me_bauru.pdf: 1561496 bytes, checksum: 413911b8f75eb43118c41dfe126407d7 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O design de embalagens de produtos de consumo deve atender a vários aspectos como segurança, conforto, eficácia, estética, entre outros. Estes elementos devem contemplar as características e capacidades dos usuários, considerando especialmente a força manual no design ergonômico das embalagens, com o objetivo de disponibilizar produtos confiáveis e seguros, de fácil acesso para usuários com capacidades limitadas (idosos) ou de difícil acesso para aqueles indivíduos que não são usuários e não deveriam acessar o produto (crianças). A falta de parâmetros biomecânicos adequados e confiáveis, de todas as faixas populacionais, incluindo as crianças, parece ser uma das causas que ainda impede os designers e a indústria de embalagens de desenvolver produtos com tampas que não impedem a ocorrência de acidentes e estão relacionados a elevados números de intoxicações envolvendo crianças. Por este motivo, o propósito desta pesquisa foi verificar as forças de manipulação empregadas durante a abertura de embalagens de água sanitária, especificamente a força de torção, ou torque, exercida por crianças (faixa etária de 2 a 5 anos) na abertura de tampas com sistema de rosca, visando apresentar parâmetros mínimos para o projeto de embalagens com tampas seguras. A metodologia empregada nesta pesquisa envolveu a utilização de três embalagens reais, adaptadas para a mensuração de torque. As três tampas analisadas possuíam dimensões diferentes e os resultados indicam uma forte influência desta variável na capacidade de aplicação de torque pelos sujeitos. Neste sentido, as dimensões recomendadas para as tampas de produtos com potencial tóxico devem ser próximas às apresentadas pela tampa de menor diâmetro desta avaliação, cujo design permitiu menor capacidade de aplicação de torque pelas crianças, o que dificultaria o acesso das mesmas, numa situação... / The design of consumption products packs must take care ofsome aspects, as security, comfort, effectiveness, aesthetic, among others. These elements must especially contemplate the characteristics and capacities of hte users, being considered the manual force in ergonomic design of the packs, with the objective of to make available trustworthy and safe products, or still, easy access for those users with limited capacities (aged) or difficult access for those individuals that are not using and they must not have access the product (children). The lack of adequate and trustworthy biomechanic parameters, of all the population bands, including the childre, seems to be one of the causes that still designers hinders and the industry of packs to developed products with really safe covers. Products with high toxic potential, as the sanitary water, are available in packs with covers that do not hinder the occurrence of accidents and, for this and other reasons are related the raised numbers of poisonings involving children. In this way, the intention of this research was to verify the used forces of manipulation during the opening of sanitary water packs, specifically the torsional force, or torque, exerted for children (age band between 2 and 5 year) in the opening of covers with thread system, aiming at to present minimum parameters for the project of packs with safe covers. The methodology used in this research involved the use of three real packs, adapted for the measure of torque. The three analyzed covers had different and the results indicate one strong influence of this variable in the capacity of aplication of torque for the citizens. In this direction, the dimensions recommended for the covers of products with toxic potential must be next to the presented ones for the cover to lesser diameter of this evaluation, whose design allowed to minor capacity of application of torque... (Complete abstract click electronic access below)

Orientador: Luis Carlos Paschoarelli / Banca: Maria Lucia Leite Ribeiro Okimoto / Banca: José Carlos Plácido da Silva / Resumo: O design de embalagens de produtos de consumo deve atender a vários aspectos como segurança, conforto, eficácia, estética, entre outros. Estes elementos devem contemplar as características e capacidades dos usuários, considerando especialmente a força manual no design ergonômico das embalagens, com o objetivo de disponibilizar produtos confiáveis e seguros, de fácil acesso para usuários com capacidades limitadas (idosos) ou de difícil acesso para aqueles indivíduos que não são usuários e não deveriam acessar o produto (crianças). A falta de parâmetros biomecânicos adequados e confiáveis, de todas as faixas populacionais, incluindo as crianças, parece ser uma das causas que ainda impede os designers e a indústria de embalagens de desenvolver produtos com tampas que não impedem a ocorrência de acidentes e estão relacionados a elevados números de intoxicações envolvendo crianças. Por este motivo, o propósito desta pesquisa foi verificar as forças de manipulação empregadas durante a abertura de embalagens de água sanitária, especificamente a força de torção, ou torque, exercida por crianças (faixa etária de 2 a 5 anos) na abertura de tampas com sistema de rosca, visando apresentar parâmetros mínimos para o projeto de embalagens com tampas seguras. A metodologia empregada nesta pesquisa envolveu a utilização de três embalagens reais, adaptadas para a mensuração de torque. As três tampas analisadas possuíam dimensões diferentes e os resultados indicam uma forte influência desta variável na capacidade de aplicação de torque pelos sujeitos. Neste sentido, as dimensões recomendadas para as tampas de produtos com potencial tóxico devem ser próximas às apresentadas pela tampa de menor diâmetro desta avaliação, cujo design permitiu menor capacidade de aplicação de torque pelas crianças, o que dificultaria o acesso das mesmas, numa situação... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The design of consumption products packs must take care ofsome aspects, as security, comfort, effectiveness, aesthetic, among others. These elements must especially contemplate the characteristics and capacities of hte users, being considered the manual force in ergonomic design of the packs, with the objective of to make available trustworthy and safe products, or still, easy access for those users with limited capacities (aged) or difficult access for those individuals that are not using and they must not have access the product (children). The lack of adequate and trustworthy biomechanic parameters, of all the population bands, including the childre, seems to be one of the causes that still designers hinders and the industry of packs to developed products with really safe covers. Products with high toxic potential, as the sanitary water, are available in packs with covers that do not hinder the occurrence of accidents and, for this and other reasons are related the raised numbers of poisonings involving children. In this way, the intention of this research was to verify the used forces of manipulation during the opening of sanitary water packs, specifically the torsional force, or torque, exerted for children (age band between 2 and 5 year) in the opening of covers with thread system, aiming at to present minimum parameters for the project of packs with safe covers. The methodology used in this research involved the use of three real packs, adapted for the measure of torque. The three analyzed covers had different and the results indicate one strong influence of this variable in the capacity of aplication of torque for the citizens. In this direction, the dimensions recommended for the covers of products with toxic potential must be next to the presented ones for the cover to lesser diameter of this evaluation, whose design allowed to minor capacity of application of torque... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2015-05-15T11:46:09Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1473576 bytes, checksum: 7ed82fab94ed8434b60fff26580cd11e (MD5) Previous issue date: 2013-08-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this work we discuss the concepts and definitions that construct Clifford algebras focusing on a introduction the theory Spin Geometry. That s because the connection this two subject, enabling such algebras know the measure that helps to understand the definition of spin manifold, concept introductory the this special topic in Riemannian Geometry. We begin with the construction of Clifford algebras associated to infinite dimensional vector spaces, over any field, passing to associated with finite dimensional. we see the spinores groups, Pin and Spin, which characterize and show the relation with the twisted adjoint representation, homomorphism that, when restricted to these groups, has an important role in defining of a spin structure. As this definition works with representations of real Clifford algebras, restricted to spinors groups such algebras, we introduced them for soon afterwards consider such representations. We concluded approaching the necessary theory for us to show that those groups are also Lie groups (where we urged an intersection with the analysis) and double covering, to complete the concepts algebraic present in the definition of spin manifold. / No presente trabalho abordamos os conceitos e definições que constroem as álgebras de Clifford com foco em uma linha de estudo de quem se inicia na teoria de Geometria Spin. Isso devido a intima ligação desses dois assunto, permitindo conhecer tais álgebras à medida que se auxilia a compreensão da definição de variedade spin, conceito introdutório desse tópico especial em Geometria Riemanniana. Iniciamos com a construção das álgebras de Clifford associadas a espaços vetoriais de dimensão infinita, sobre um corpo qualquer, passando àquelas associadas aos de dimensão finita. Fazemos o mesmo com os grupos Pin e Spin, os quais caracterizamos e mostramos a relação com a representação adjunta torcida, aplicação que, quando restrita a esses grupos, tem papel importante na definição de uma estrutura spin. Como tal definição trabalha com representações das álgebras de Clifford reais, restritas aos grupos spinores dessas Cliffords, as apresentamos para em seguida conceituarmos tais representações. Finalizamos, para completar os conceitos algébricos presente na definição de variedade spin, abordando a teoria necessária para mostrarmos que esses grupos são também grupos de Lie (onde instigamos uma interseção com a análise, destacando os enlaces com outras teorias) e recobrimentos duplos.

Orientador: Marcos Benevenuto Jardim / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Matemática, Estatística e Computação Científica / Made available in DSpace on 2018-08-24T02:07:51Z (GMT). No. of bitstreams: 1 Castilho_TiagoNunes_D.pdf: 20018125 bytes, checksum: 181cd44948098969af37059c2215917a (MD5) Previous issue date: 2013 / Resumo: Esta tese trata de variedades de Prym e de semigrupos de Weierstrass, ambos no contexto de recobrimentos duplos de curvas ramificados. A partir da descrição da variedade de Prym em termos de um conjunto de fibrações lineares do recobrimento, estuda-se a dualidade entre o lugar onde a aplicação de Gauss sobre o divisor Prym-Theta se degenera e o divisor de ramos do recobrimento duplo, em que provarse uma relação entre as fibras da aplicação de Gauss e os semigrupos de Weierstrass das ramificações do recobrimento / Abstract: ln this thesis we present results about Prym varieties and Weierstrass semigroups, both in the context of ramified double covers of curves. From the description of the Prym variety by a set of linear fibrations, we study the duality between the place where the Gauss map on the Prym-Theta divisor degenerates and the branch divisor of the double covering, in which we prove a relation between the fibers of the Gauss map and the Weierstrass semigroups of branched points of the double covering / Doutorado / Matematica / Doutor em Matemática