Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 17 of 17 for “"elliptic problems"”.
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Elliptic problems with small parameter
… and correctness of asymptotic solutions to elliptic differential and pseudodifferential equations. We begin our studies with the case of a general elliptic boundary value problem in partial derivatives. A small parameter enters the coefficients of the main equation as well as into the …
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Solutions of minimal energy for elliptic problems
Questa tesi di Dottorato riguarda lo studio dell'esistenza di soluzioni di minima energia e soluzioni nodali di minima energia per problemi ellittici non lineari in presenza di una nonlinearità con condizioni di crescita subcritica. La tesi è divisa in tre capitoli. Nel primo capitolo vengono …
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Supercritical Semi-Linear Elliptic Problems Using Variational Principles
… the use of variational methods to study elliptic partial differential equations (PDEs) with supercritical nonlinearities. By focusing on convex subsets of a Banach space, the research overcomes compactness issues typically encountered with nonlinearities that exceed the Sobolev embedding …
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An Adaptive Multilevel Method for Anisotropic Elliptic Problems
A C++ implementation, ASR - MG++ , of the ASR-MG method is described, and experimental results for different sub-methods are presented.
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Unified Multilevel Adaptive Finite Element Methods for Elliptic Problems
Many elliptic partial differential equations can be solved numerically with near optimal efficiency through the uses of adaptive refinement and multigrid solution techniques. It is our goal to develop a more unified approach to the combined process of adaptive refinement and multigrid solution …
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A multiscale framework for Bayesian inference in elliptic problems
The Bayesian approach to inference problems provides a systematic way of updating prior knowledge with data. A likelihood function involving a forward model of the problem is used to incorporate data into a posterior distribution. The standard method of sampling this distribution is Markov chain …
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Parallel Domain Decomposition Preconditioning for the Adaptive Finite Element Solution of Elliptic Problems in Three Dimensions
… for the parallel finite element solution of elliptic partial differential equations in three dimensions. This algorithm allows each processor to be assigned one or more subdomains and, as with most parallel domain decomposition solvers, each processor is able to solve its own subproblem(s) …
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Reduced basis approximation and a posteriori error estimation for non-coercive elliptic problems : applications to acoustics
Modern engineering problems often require accurate, reliable, and efficient evaluation of quantities of interest, evaluation of which demands the solution of a partial differential equation. We present in this thesis a general methodology for the predicition of outputs of interest of non-coercive …
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Sobre a teoria de regularidade elíptica via análise da equação de Helmholtz em RN
… used to regularize weak solutions of nonlinear elliptic problems in RN. In order to achieve our goals, it will be of vital importance the use of Bessel’s Modified Function Theory, Calderón-Zygmund Theory, the Mountain Pass Theorem and Schauder’s Theorem, as well as basic results of Measure and …
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A parallel second order Cartesian method for elliptic interface problems and its application to tumor growth model
… deals with a parallel Cartesian method to solve elliptic problems with complex interfaces and its application to elliptic irregular domain problems in the framework of a tumor growth model. This method is based on a finite differences scheme and is second order accurate in the whole domain. The …
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Geometric Computing beyond the Laplacian
… insights from optimal control and inverse PDE problems, we propose efficient numerical schemes to search for the metric or conformal structure whose associated (generalized) Laplacian is optimal for a given task, or explicitly design operators as suggested by modern spectral geometry. …
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Immersed and Discontinuous Finite Element Methods
… local discontinuous Galerkin method for elliptic problems and construct optimal immersed finite element approximations and discontinuous immersed finite element methods for the Stokes interface problem. In the first part we present an error analysis for the minimal dissipation local …
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Signal transmission in epithelial layers
… reaction-diffusion equations leads to nonlinear elliptic boundary-value problems. We take advantage of this property and develop an extension of the method of Optimal Grids for elliptic problems. We call this method Compensated Optimal Grids. We present its application and study its convergence …
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Generalizing smoothed aggregation-based algebraic multigrid
… SA has been effective over a broad class of problems, it has several limitations and weaknesses that this thesis is intended to address. This includes the development of a more robust strength-of-connection measure which guides coarsening and the choice of interpolation sparsity patterns. …
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Solving variable coefficient partial differential equations using the boundary element method.
… DR-BEM is tested in this thesis for a range of elliptic variable coefficient PDEs. The results of these test problems indicate that the DR-BEM is a promising method for solving elliptic variable coefficient PDEs. However, in some cases, such as problems in highly heterogeneous media, it is found …
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Refined theories and Discontinuous Galerkin methods for the analysis of multilayered composite structures
… Galerkin method applied to structural problems is presented, a beam and a shell DG elements are formulated and the DG method is used besides a cohesive zone model to the study of the delamination's propagation process in laminate composite materials. In the following chapter Refined …
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PROBLEMI ELLITTICI COINVOLGENTI NONLINEARITA' INDEFINITE NEL SEGNO
Sia $\Omega$ un dominio limitato in $\R^N$, $N\geq 3$. In questa tesi studiamo due problemi ellittici con nonlinearità indefinita nel segno. Siano $\alpha,\beta:\Omega\to\R$ due funzioni misurabili e siano $s\in]1,2[$, $r\in]1,s[$. Per prima cosa ci occupiamo del seguente problema ellittico non …