Dissertação (Mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. / Made available in DSpace on 2012-10-18T23:37:30Z (GMT). No. of bitstreams: 0Bitstream added on 2016-01-09T03:41:35Z : No. of bitstreams: 1 138936.pdf: 2231123 bytes, checksum: 2bb6b950f71e850bf6cd04a19af863d5 (MD5)

Orientador: Christiano Lyra Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica / Made available in DSpace on 2018-07-14T01:27:33Z (GMT). No. of bitstreams: 1 Oliveira_AurelioRibeiroLeitede_M.pdf: 7874516 bytes, checksum: 7414fce52e5e9596ebc63cbac785be46 (MD5) Previous issue date: 1989 / Resumo: Não informado / Abstract: Not informed. / Mestrado / Mestre em Engenharia Elétrica

Orientador : Miguel Taube Netto / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Cientifica / Made available in DSpace on 2018-07-14T02:56:07Z (GMT). No. of bitstreams: 1 AndradeJunior_Olympiode_M.pdf: 986899 bytes, checksum: 3f299e4928cbf1b16d8e9f8878e55f06 (MD5) Previous issue date: 1983 / Resumo: Não informado. / Abstract: Not informed. / Mestrado / Mestre em Matemática Aplicada

Orientador: Miguel Taube Netto / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Ciencia da Computação / Made available in DSpace on 2018-07-14T03:31:23Z (GMT). No. of bitstreams: 1 Arenales_MarcosNereu_M.pdf: 704091 bytes, checksum: 1de3a0287dec7c7b468d8f9c617f5c7f (MD5) Previous issue date: 1979 / Resumo: Não informado. / Abstract: Not informed. / Mestrado / Mestre em Matemática Aplicada

Orientador: Hermano de Medeiros F. Tavares / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Ciencia da Computação / Made available in DSpace on 2018-07-14T06:10:00Z (GMT). No. of bitstreams: 1 Cardoso_MarioAndrade_M.pdf: 1285975 bytes, checksum: 6684627ca1fae0d5cee6f0211626d55e (MD5) Previous issue date: 1981 / Resumo: Não informado. / Abstract: Not informed. / Mestrado / Mestre em Matemática Aplicada

Orientador: Hermano de Medeiros F. Tavares / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Campinas / Made available in DSpace on 2018-07-14T09:57:11Z (GMT). No. of bitstreams: 1 Ferreira_EdsondePaula_M.pdf: 1453191 bytes, checksum: afbf258d4d63b053749b020af47cdf54 (MD5) Previous issue date: 1978 / Resumo: Desenvolvemos o método Primal-Dual para problemas cuja função objetivo a minimizar é convexa linear por partes, numa formulação baseada na dualidade segundo a teoria de Lagrange. No capítulo 1 é feita uma nova caracterização do método Primal-Dual linear (DANTZIC, FORD, FULKERSON), e uma apresentação dos aspectos novos no tratamento de problemas lineares por partes. No capítulo 2 apresentamos o problema linear por partes e fazemos o desenvolvimento do método em questão. No capítulo 3 resolvemos um problema auxiliar pelo método primal linear por partes (YOUDINE) adequado às características particulares do problema. No capítulo 4 reapresentamos os métodos Primal e Dual Simplex linear por partes (CARCIA) e fazemos uma análise conjunta nos aspectos qualitativos relevantes dos três métodos em questão / Abstract: Not informed. / Mestrado / Mestre em Engenharia Elétrica

In this research study, non-linear spectral mixing models have been developed and employed to achieve unmixing the proportions of components accurately and retrieving the physical parameters of the mixture. The first focus is on a comparative study of linear and non-linear spectral mixing models. A carefully-controlled experiment was conducted in the laboratory. The aim is to test both models to unmix ternary powdered-chalk mixtures by using the directional reflectance data. The results demonstrated the superiority of the non-linear model over the linear model. However, there was at least one case when the linear model produced more accurate results than the non-linear model. As a consequence, a hypothesis was made that the directional reflectance data obtained from certain measurement geometries may not contain useful information for deriving surface parameters. In order to investigate this, an error analysis was employed to observe the sensitivity to error of a physical parameter, which is needed in the non-linear unmixing, when estimated from directional reflectance data at certain measurement geometries. This theoretical investigation was tested against reflectance data of mineral mixtures obtained from a laboratory experiment. The results showed that the unmixing could be improved when the angular measurements were carefully chosen. Information contained in each surface measurement can be useful or damaging depending on the measurement geometry and the brightness of the surface itself. The next focus is on the utilisation of non-linear spectral mixing model to retrieve the biophysical properties of vegetation canopies by means of a canopy reflectance modelling. A two-layer model of the bidirectional reflectance of homogeneous vegetation canopies was proposed in this study. The anisotropic scatterings of both the vegetation canopy and the background were taken into account. This new model was validated against simulated and field-measurement data. The results showed that this model can be used to model the bidirectional reflectance and to retrieve the optical properties of canopy elements (leaves) and background of a homogeneous canopy. Finally, a simple non-linear spectral mixing model was developed. The second order interaction between vegetation and soil was taken into account. Results from the experiments showed that the vegetation cover and leaf area index of moderate density canopies can be retrieved by using this model.

In this dissertation, we study certain types of linear mappings on triangular algebras. Triangular algebras are algebras whose elements can be written in the form of 2 x 2 matrices [special characters omitted]where a ∈ A, b ∈ B, m ∈ M and where A, B are algebras and M is a bimodule. Many widely studied algebras, such as upper triangular matrix algebras and nest algebras, can be viewed as triangular algebras. This dissertation is divided into five chapters. The first chapter is a general account of the basics of triangular algebras, including the unitization of nonunital triangular algebras and the structure of the centre of triangular algebras, as well as a brief introduction to some well-known examples of triangular algebras. In Chapter 2, we study the general structure of derivations on triangular algebras and obtain some results on the first cohomology groups of triangular algebras. The first cohomology group of an algebra is the quotient space of the space of all derivations over the space of all inner derivations, and it is always a main tool in the research of derivations. In addition, we consider the problem of automatic continuity of derivations in the last section of this chapter. In Chapter 3, we consider sufficient conditions on a triangular algebra so that every Lie derivation is a sum of a derivation and a linear map whose image lies in the centre of the triangular algebra. In Chapter 4, we consider sufficient conditions for every commuting map on a triangular algebra to be a sum of a map of the form x ↦ ax and a map whose image lies in the centre of the triangular algebra. In the final chapter, we are concerned with the automorphisms of triangular algebras. The study of automorphism is a most important way to understand the underlying structure of an algebra. We deduce some results on the Skolem-Noether groups, or the outer automorphism groups, of triangular algebras and apply those results to generalize some known results about automorphisms on a triangular matrix algebras. / Graduate

A method for the making of non linear barium titanate condensers for audio frequencies is described. Preliminary measurements on these condensers are given. An idealized theory for the behaviour of the non linear condensers in a carrier amplifier circuit is developed. A carrier amplifier built on this principle is described. A theoretically possible power amplification for this amplifier of 180 is derived. Experimental results obtained with the carrier amplifier are given. A power amplification of 70 was obtained. Conclusions on the possible applications of non linear condensers are drawn. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

The notion of the 'classical' multilinear maps such as the symmetric and skew-symmetric maps, has the following generalization: given a vector-space V and a pair (H[subscript n],X[subscript n]) where is a subgroup of the symmetric group S[subscript n] and X[subscript n] is a character of H[subscript n], we consider multilinear maps from V[superscript n] (n-fold cartesian product of V ) into any other vector space, which are ‘symmetric with respect to (H[subscript n],X[subscript n])’, i.e., which have a certain symmetry in their values on permuted tuples of vectors, where the permutations are in H[subscript n]. Given a pair (H[subscript n],X[subscript n]) and a vector-space V , we can construct a space V[superscript (n)] over V through which the maps 'symmetric with respect to (H[subscript n],X[subscript n])’ linearize. The space V[superscript (n)] is usually defined abstractly by means of a certain universal mapping property and gives the tensor, symmetric and Grassmarm spaces for the 'classical' maps. Given a sequence of pairs [formula omitted]and the corresponding spaces V[superscript (n)], we let [formula omitted] (where V[superscript b]) is the ground field). In the classical cases, A has a natural multiplicative operation which makes A an algebra, i.e., the Tensor, Symmetric and Grassmann algebras. This presentation has been motivated by the attempt to generalize the construction of an algebra A to a wider family of 'admissible' sequences of pairs [formula omitted]. This consideration has led us to investigate permutation groups on the numbers 1,2,3,… which are closed under a certain 'shift' of the permutations, i.e., if [formula omitted] is a permutation, we define [formula omitted] and we call a permutation group H 'translation-invariant' if for every [formula omitted] is also in H . We begin our presentation by characterising the 'translation-invariant' groups. We show that the study of these (infinite) groups can be reduced to the study of certain finite groups. Then, we proceed to discuss the lattice of the translation-invariant groups. Finally, we show that a translation-invariant group H , together, with an appropriate character X of H , represents an equivalence class of 'admissible' sequences of pairs [formula omitted]. For a particular choice of representatives of the equivalence class, we can construct an algebra of 'symmetry classes of tensors' which generalizes the Tensor, Symmetric and Grassmann algebras. / Science, Faculty of / Mathematics, Department of / Graduate