Spectral Theorem
Mostrando 1-11 de 11 artigos, teses e dissertações.
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1. Spectral analysis in determining water quality sampling intervals
RESUMO Para gerar séries históricas de qualidade da água mais representativas desenvolvem-se técnicas de monitoramento em tempo real. Contudo, estas técnicas possuem obstáculos quanto ao uso: alto custo, dificuldades de instalação, manutenção e calibração dos equipamentos. Uma alternativa seria o chamado monitoramento da qualidade da água em tem
RBRH. Publicado em: 07/10/2019
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2. Positive integral operators and reproducing kernel Hilbert spaces / Operadores integrais positivos e espaços de Hilbert de reprodução
In this work we study theoretical properties of positive integral operators on L POT. 2(X; u), in the case when X is a topological space, either locally compact or first countable, and u is a strictly positive measure. The analysis is directed to spectral properties of the operator which are related to some extensions of Mercers Theorem and to the study of t
Publicado em: 2010
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3. Espectro e dimensão Hausdorff de operadores bloco-Jacobi com perturbações esparsas distribuídas aleatoriamente / Spectrum and Hausdorff dimension of block-Jacobi matrices with sparse perturbations randomly distributed
Neste trabalho buscamos caracterizar o espectro de uma classe de operadores bloco--Jacobi limitados definidos em $l^2(\Lambda,\mathbb{C}^L)$ ($\Lambda: \mathbb{Z}_+\times\{0,1,\ldots,L-1\}$ representa uma faixa de largura $L\ge 2$ no semi--plano $\mathbb{Z}_+^2$) e sujeitos a perturbações esparsas (no sentido que as distâncias entre as ``barreirascrescem
Publicado em: 2010
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4. UMA SOLUÇÃO PARA A EQUAÇÃO DA ENERGIA CINÉTICA TURBULENTA EMPREGANDO O MÉTODO DAS CARACTERÍSTICAS / A SOLUTION FOR THE TURBULENT KINETIC ENERGY EQUATION EMPLOYING THE METHOD OF CHARACTERISTICS
In this study, using the Method of Characteristics and numeric resources, presents a solution to the equation Spectral Density Evolution of Turbulent Kinetic Energy for a Convective Boundary Layer (CBL) in the morning. It presents three models for the evolution of spectral energy density. The first model, based on the assumption of a system of isotropic turb
Publicado em: 2009
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5. CONVENTIONAL AND SIMPLIFIED-HYBRID BOUNDARY ELEMENT METHODS APLLIED TO AXISYMMETRIC ELASTICITY PROBLEMS IN FULLSPACE AND HALFSPACE / MÉTODOS DE ELEMENTOS DE CONTORNO CONVENCIONAL E HÍBRIDO SIMPLIFICADO APLICADOS A PROBLEMAS AXISSIMÉTRICOS DE ELASTICIDADE NO ESPAÇO COMPLETO E NO SEMI-COMPLETO
This thesis presents the formulation of the conventional and simplified-hybrid boundary element methods for axisymmetric problems, employng fullspace as well as halfspace fundamental solutions. As it is mostly found in the literature on axisymmetric problems in the elastic halfspace, the boundary element formulations make use of fullspace fundamental solutio
Publicado em: 2009
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6. Variação primeira e segunda para o primeiro autovalor de um problema elíptico / First and second variation of the first eigenvalue of an elliptic problem
Consideraremos o problema elípitco $-\Delta u + \alpha\chi_Du = \lambda u$ em $\Omega$, onde $\Omega$ é um domínio de R^n com fronteira regular, e $D\subset \Omega$ é um subconjunto fechado de medida de Lebesgue fixada. A motivação para este problema vem da Mecânica, onde esta equação é encontrada no estudo de vibrações de uma membrana composta.
Publicado em: 2007
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7. DISTORÇÃO ESPECTRAL DE SINAIS OFDM DEVIDA À NÃO-LINEARIDADE DO CANAL DE TRANSMISSÃO / SPECTRAL DISTORTION OF OFDM SIGNALS DUE TO CHANNEL NON-LINEARITY
This MSc dissertation presents a theoretical analysis that evaluates the distortion experienced by the power spectrum density of OFDM signals when they are transmitted through a non-linear channel. The complex envelope of the OFDM signals are modeled as a complex proper gaussian random process and the channel non-linearity is characterized through a power se
Publicado em: 2006
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8. Simulations of plasmas with electrostatic PIC models using the finite element method
Particle-in-cell (PIC) methods allow the study of plasma behavior by computing the trajectories of finite-size particles under the action of external and self-consistent electric and magnetic fields defined in a grid of points. In this work, the Finite Element Method (FEM) is used in order to obtain the self-consistent fields. An electrostatic PIC-FEM comput
Brazilian Journal of Physics. Publicado em: 2003-06
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9. Impacto dos contrastes de interesse no delineamento de um experimento em blocos
Pearce s conceptions on statistical planning of experiments are explored in this work. The construction process of block designs was especially considered, in order to obtain experimental designs that depend upon the experimenter s needs. This way, the work is oriented basically to the study of contrasts of chief interest, because they are directly related w
Publicado em: 1993
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10. Infinitesimal generators and quasi-units in potential theory
The underlying structure is taken as a strongly superharmonic cone [unk], defined as a partially ordered abelian semigroup with identity 0 which admits a multiplication by nonnegative scalars and satisfies two fundamental axioms of a potentialtheoretic character. In terms of a fixed nonzero element e there is introduced on [unk] a one-parameter family of non
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11. Reduction, the trace formula, and semiclassical asymptotics
We state a theorem that relates the theory of dimensional reduction in Hamiltonian mechanics to the spectral properties of elliptic operators with symmetries on compact manifolds. As an application, we show that the spectrum of the Schrödinger operator, -[unk]hΔ + V, as [unk]h → 0, contains geometric information about the closed trajectories of a classic