Integral Operators
Mostrando 1-12 de 30 artigos, teses e dissertações.
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1. Decaimento dos autovalores de operadores integrais positivos gerados por núcleos Laplace-Beltrami diferenciáveis / Eigenvalue decay of positive integral operators generated by Laplace-Beltrami differentiable kernels
Neste trabalho obtemos taxas de decaimento para autovalores e valores singulares de operadores integrais gerados por núcleos de quadrado integrável sobre a esfera unitária em \ R POT. m+1\ , m 2, sob hipóteses sobre ambos, certas derivadas do núcleo e o operador integral gerado por tais derivadas. Este tipo de problema é comum na literatura, mas as hip
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 08/08/2011
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2. On asymptotic analysis of spectral problems in elasticity
The three-dimensional spectral elasticity problem is studied in an anisotropic and inhomogeneous solid with small defects, i.e., inclusions, voids, and microcracks. Asymptotics of eigenfrequencies and the corresponding elastic eigenmodes are constructed and justified. New technicalities of the asymptotic analysis are related to variable coefficients of diffe
Latin American Journal of Solids and Structures. Publicado em: 2011
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3. 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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4. Partial sums of analytic functions of bounded turning with applications
In this article, we determine certain conditions under which the partial sums of the multiplier integral operators of analytic univalent functions of bounded turning are also of bounded turning.
Computational & Applied Mathematics. Publicado em: 2010
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5. Weak solutions for the electrophoretic motion of charged particles
We introduce a weak formulation for a system of electrostatic and hydrodynamic equations modelling the electrophoretic motion of charged particles in ionized fluids. We obtain a local in time existence theorem, using the results established in [11] and properties of the solutions of the Poisson-Boltzmann equation. These properties follows from singular integ
Publicado em: 2010
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6. Operadores integrais gerados por núcleos em multi-escalas / Integral operators generated by multi-scale kernels
We study Mercer like kernels, a very special class of positive definite kernels possessing the description given by many results labeled as Mercers Theorem. We explore some of their properties which are needed in the development of this work and construct their native space. In the second half of the work, we consider Mercer kernels defined by a multi-scale
Publicado em: 2009
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7. Método da média para equações diferenciais funcionais retardadas impulsivas via equações diferenciais generalizadas / Averaging method for retarded functional differential equations with impulses by generalized ordinary differential equations
In this present work, we condider the following initial value problem for a retarded functional differential equation with impulses { x POINT= varepsilonf (t, x IND.t), t DIFFERENTt IND. k, DELTAx(t IND. k) = varepsilonI IND. k(x ( t IND.k)), k = 0, 1, 2, ... x IND. t IND.0= phi, where f está defined in a open set OMEGAde R x G POT. -([- r, 0], R POT. n), r
Publicado em: 2009
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8. Holomorphy types on a Banach spaces / Tipos de holomorfia em espaços de Banach
In this work we introduce and study functions of ?-holomorphy type of bounded type. In particular we obtain a duality result via the Borel transform and we prove existence and approximation results for convolution equations. The results we prove generalize previous results of this type due to C. Gupta [21], M. Matos [28] and X. Mujica [32]. We study the rela
Publicado em: 2008
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9. Space-time finite element approximation andnumerical solution of hereditary linearviscoelasticity problems
In this paper we suggest a fast numerical approach to treat problems of the hereditary linear viscoelasticity, which results in the system of elliptic partial differential equations in space variables, who's coefficients are Volterra integral operators of the second kind in time. We propose to approximate the relaxation kernels by the product of purely time-
Computational & Applied Mathematics. Publicado em: 2008
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10. Weak solutions for the electrophoretic motion of charged particles
We introduce a weak formulation for a system of electrostatic and hydrodynamic equations modelling the electrophoretic motion of charged particles in ionized fluids. We obtain a local in time existence theorem, using the results established in [11] and properties of the solutions of the Poisson-Boltzmann equation. These properties follows from singular integ
Computational & Applied Mathematics. Publicado em: 2006
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11. VIDRO DE SPIN E ANTIFERROMAGNETISMO COM INTERACÃO DE PAREAMENTO BCS LOCAL
In this work the competition among spin glass(SG), antiferromagnetism (AF) and BCS pairs formation (PAIR) in real space is investigated. The model consists of an Ising spin glass term and a local BCS term that favors double site occupation. This model is composed by two sublattices, but only spins in diferent sublattices can interact. The Ising coupling is a
Publicado em: 2005
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12. Introdução de um "Quantum" de tempo no formalismo da mecanica quantica
Discovered nearly a century ago, the electron is still a stranger in the context of classical electromagnetism. Many models have been proposed in order to describe it. In this sense, the most successful theory is the one proposed by Dirac in 1938, notwithstanding some drawbacks such as the existence of pre-accelerating and self-accelerating solutions. An alt
Publicado em: 1994