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published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy

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Submitted by LUIZ FERNANDO GIOLO ALVES null (luizimgiolo@gmail.com) on 2016-09-29T21:43:31Z No. of bitstreams: 1 tmp_12169-dissertacao-1032011706.pdf: 3377970 bytes, checksum: 5530be5b26b39526c11f2e04d66a486f (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-10-05T12:38:39Z (GMT) No. of bitstreams: 1 alves_lfg_me_rcla.pdf: 3377970 bytes, checksum: 5530be5b26b39526c11f2e04d66a486f (MD5) / Made available in DSpace on 2016-10-05T12:38:39Z (GMT). No. of bitstreams: 1 alves_lfg_me_rcla.pdf: 3377970 bytes, checksum: 5530be5b26b39526c11f2e04d66a486f (MD5) Previous issue date: 2016-08-31 / O texto que segue aborda um estudo de cônicas e quádricas com o objetivo de auxiliar professores e estudantes a ter uma visão mais concreta e dinâmica destes elementos com o software de distribuição livre GeoGebra. Num primeiro momento temos como alvo observações sobre cônicas com dicas de como dirigir-se ao assunto usando as ferramentas que o GeoGebra traz para facilitar o entendimento dos significados dos parâmetros e coeficientes dessas equaçõees quadráticas. Em seguida, estudamos algumas particularidades das quádricas, assunto que usualmente não é visto no ensino médio. / The following text is a study of conics and quadrics with a goal to give a concrete and dinamic approach of the subject with the assistance of the free software GeoGebra. At first moment we target some observations about conics, with tips of how to approach the subject with the tools that GeoGebra brings to make easier the understanding of the meanings of the parameters and coefficients of these quadratic equations. And then we study some particularities of the quadric surfaces, a subject that usually is not seen in the high school.

Orientadores: Sueli Irene Rodrigues Costa, Simão Nicolau Stelmastchuk / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Instituto de Matemática, Estatística e Computação Científica / Made available in DSpace on 2018-08-10T23:29:23Z (GMT). No. of bitstreams: 1 Tavares_FabianoPinto_M.pdf: 877532 bytes, checksum: 0081c7182db3aab71edcbe274822bea5 (MD5) Previous issue date: 2008 / Resumo: Neste trabalho focalizamos a deformação de cônicas e quádricas por transformações lineares. Deduzimos de forma explícita os autovalores e autovetores ortonormais de matrizes reais 2 x 2 e 3 x 3, para os quais não há quase referências na literatura e nem incorporação nos programas computacionais de cálculo simbólico usuais. Esta determinação levou -nos a estudar um pouco da história da resolução das equações de terceiro grau e das condições e formulações das raízes reais destas. Os resultados foram utilizados na determinação explícita das deformações por transformações lineares de cônicas e quádricas, sendo estas discutidas em termos de características das matrizes associadas / Abstract: We discuss here the deformations of conics and quadrics under linear mappings. We set explicitly the eingenvalues and the orthonormal eigenvectors of real symmetric 2 X 2 and 3 X 3 matrices. These expressions are scarce in the literature and not incorporated in symbolic calculus software. The determination of those eigenvalues leaded us to the study of the solution of third degree equations and some of related historical aspects with focus on conditions and expressions for their real solutions Those results are used in the exact determination of the linear deformation of conics and quadrics in terms of the characteristics of their associated matrices / Mestrado / Geometria Topologia / Mestre em Matemática

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The use of digitized information is rapidly gaining acceptance in bio-medical applications. Video compression plays an important role in the archiving and transmission of different digital diagnostic modalities. The present scheme of video compression for low bit-rate networks is not suitable for medical video sequences. The instability is the result of block artifacts resulting from the block based DCT coefficient quantization. The possibility of applying deformable motion estimation techniques to make the video compression standard (H.263) more adaptable for bio-medial applications was studied in detail. The study on the network characteristics and the behavior of various congestion control mechanisms was used to analyze the complete characteristics of existing low bit rate video compression algorithms. The study was conducted in three phases. The first phase involved the implementation and study of the present H.263 compression standard and its limitations. The second phase dealt with the analysis of an external force for active contours which was used to obtain estimates for deformable objects. The external force, which is termed Gradient Vector Flow (GVF), was computed as a diffusion of the gradient vectors associated with a gray-level or binary edge map derived from the image. The mathematical aspect of a multi-scale framework based on a medial representation for the segmentation and shape characterization of anatomical objects in medical imagery was derived in detail. The medial representations were based on a hierarchical representation of linked figural models such as protrusions, indentations, neighboring figures and included figures--which represented solid regions and their boundaries. The third phase dealt with the vital parameters for effective video streaming over the internet in the bottleneck bandwidth, which gives the upper limit for the speed of data delivery from one end point to the other in a network. If a codec attempts to send data beyond this limit, all packets above the limit will be lost. On the other hand, sending under this limit will clearly result in suboptimal video quality. During this phase the packet-drop-rate (PDR) performance of TCP(1/2) was investigated in conjunction with a few representative TCP-friendly congestion control protocols (CCP). The CCPs were TCP(1/256), SQRT(1/256) and TFRC (256), with and without self clocking. The CCPs were studied when subjected to an abrupt reduction in the available bandwidth. Additionally, the investigation studied the effect on the drop rates of TCP-Compatible algorithms by changing the queuing scheme from Random Early Detection (RED) to DropTail.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Este trabalho trata do reconhecimento de quÃdricas utilizando o mÃtodo de diagonalizaÃÃo de matrizes 3 x 3. No inÃcio à apresentada a definiÃÃo de quÃdricas, as equaÃÃes padrÃes seguidas de seus respectivos nomes e representaÃÃes geomÃtricas. Seguem-se entÃo as ideias de autovalores e autovetores de uma transformaÃÃo linear que servem de base para a diagonalizaÃÃo de matrizes. Logo apÃs sÃo discutidas a independÃncia linear de autovetores bem como suas propriedades de formarem uma base de um espaÃo vetorial. A condiÃÃo para que toda matriz quadrada seja diagonalizÃvel à apresentada em seguida, bem como as particularidades de uma matriz simÃtrica. A demonstraÃÃo de que toda matriz simÃtrica à diagonalizÃvel à feita a partir de uma abordagem matricial, elegante e elementar. O reconhecimento de quÃdricas à feito a partir de cÃlculos bÃsicos, utilizando alguns conteÃdos amplamente explorados no Ensino MÃdio tais como: matrizes, determinantes, sistemas lineares e equaÃÃes algÃbricas. No final à apresentada uma forma de ensinar quÃdricas na escola utilizando o software educacional Winplot. / This paper deals with the recognition of quadrics using the method of diagonalization of matrices 3 à 3. Earlier it shows the definition of quadrics, the standard equations followed by their names and geometric representations. Then follows the ideas of eigenvalues and eigenvectors of a linear transformation that are the basis for the diagonalization of matrices. Immediately after the linear independence of the eigenvectors is discussed as well as their properties of forming a basis of a vector space. The condition for any square matrix be diagonalizable is shown after, as well as the particularities of a symmetric matrix. The demonstration that all 3 à 3 symmetric matrix is diagonalizable is made from an elegant and elemental matrix approach. Recognition of quadrics is made from basic calculations using some content widely exploited in high school such as matrices, determinants, linear systems and algebraic equations. At the end it presents a way of teaching quadrics in school using educational software Winplot.