The tridiagonalization and its back-transformation for computing eigen-pairs of real symmetric dense matrices are known to be the bottleneck of the execution time in parallel processing owing to the communication cost...
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ISBN:
(数字)9783319624266
ISBN:
(纸本)9783319624266;9783319624242
The tridiagonalization and its back-transformation for computing eigen-pairs of real symmetric dense matrices are known to be the bottleneck of the execution time in parallel processing owing to the communication cost and the number of floating-point operations. To overcome this problem, we focus on real symmetric band eigensolvers proposed by Gupta and Murata since their eigensolvers are composed of the bisection and inverse iteration algorithms and do not include neither the tridiagonalization of real symmetric band matrices nor its back-transformation. In this paper, the following parallel solver for computing a subset of eigenpairs of real symmetric band matrices is proposed on the basis of Murata's eigensolver: the desired eigenvalues of the target band matrices are computed directly by using parallel Murata's bisection algorithm. The corresponding eigenvectors are computed by using block inverse iteration algorithm with reorthogonalization, which can be parallelized with lower communication cost than the inverse iteration algorithm. Numerical experiments on shared-memory multi-core processors show that the proposed eigensolver is faster than the conventional solvers.
This work considers the combined space-time discretization of time-dependent partial differential equations by using first order least square methods. We also impose an explicit constraint representing space-time mass...
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In this article, we use the theory of meshfree approximation to generalize the simple kriging methods by kernel-based probabilities. The main idea is that the new kriging estimations are modeled by the Gaussian fields...
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ISBN:
(数字)9783319519548
ISBN:
(纸本)9783319519548;9783319519531
In this article, we use the theory of meshfree approximation to generalize the simple kriging methods by kernel-based probabilities. The main idea is that the new kriging estimations are modeled by the Gaussian fields indexed by bounded linear functionals defined on Sobolev spaces. Moreover, the covariances of the Gaussian fields at the observed functionals can be computed by the given co-variance kernels with respect to the related functionals, for example, Gaussian kernels evaluated at points and gradients. This guarantees that the generalized kriging estimations can be obtained by the same techniques of the simple kriging methods and the generalized kriging estimations can cover many kinds of the complex observed information. By the generalized kriging methods, we can model the geostatistics with the additional observations of gradients at the uncertain locations.
In this paper we present a general approach to embed arbitrary approximation spaces into classical finite element simulations in a non-intrusive fashion. To this end, we employ a global partition of unity method to sp...
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ISBN:
(数字)9783319519548
ISBN:
(纸本)9783319519548;9783319519531
In this paper we present a general approach to embed arbitrary approximation spaces into classical finite element simulations in a non-intrusive fashion. To this end, we employ a global partition of unity method to splice the two independent approximation spaces together. The main goal of this research is to enable the timely evaluation of novel discretization approaches and meshfree techniques in an industrial context by embedding them into large scale finite element simulations. We present some numerical results showing the generality and effectiveness of our approach.
A scalable parallel solver for (div) problems discretized by arbitrary order finite elements on general unstructured meshes is proposed. The solver is based on hybridization and algebraic multigrid (AMG). The hybridiz...
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In 2006 the Multipreconditioned Conjugate Gradient (MPCG) algorithm was introduced by Bridson and Greif. It is an iterative linear solver, adapted from the Preconditioned Conjugate Gradient (PCG) algorithm which can b...
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The Sakurai-Sugiura (SS) projection method for the generalized eigenvalue problem has been extended to the nonlinear eigenvalue problem A(z)w = 0, where A(z) is an analytic matrix valued function, by several authors. ...
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ISBN:
(数字)9783319624266
ISBN:
(纸本)9783319624266;9783319624242
The Sakurai-Sugiura (SS) projection method for the generalized eigenvalue problem has been extended to the nonlinear eigenvalue problem A(z)w = 0, where A(z) is an analytic matrix valued function, by several authors. To the best of the authors' knowledge, existing derivations of these methods rely on canonical forms of an analytic matrix function such as the Smith form or the theorem of Keldysh. While these theorems are powerful tools, they require advanced knowledge of both analysis and linear algebra and are rarely mentioned even in advanced textbooks of linear algebra. In this paper, we present an elementary derivation of the SS-type algorithm for the nonlinear eigenvalue problem, assuming that the wanted eigenvalues are all simple. Our derivation uses only the analyticity of the eigenvalues and eigenvectors of a parametrized matrix A(z), which is a standard result in matrix perturbation theory. Thus we expect that our approach will provide an easily accessible path to the theory of nonlinear SS-type methods.
A Newton-Krylov-FETI-DP method for solving nonlinear partial differential equations is presented. The FETI-DP method, which is applied in each Newton step, has an adaptively enriched coarse space to deal with ill-cond...
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This paper presents a multiscale Petrov-Galerkin finite element method for time-harmonic acoustic scattering problems with heterogeneous coefficients in the high-frequency regime. We show that the method is pollution-...
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ISBN:
(数字)9783319519548
ISBN:
(纸本)9783319519548;9783319519531
This paper presents a multiscale Petrov-Galerkin finite element method for time-harmonic acoustic scattering problems with heterogeneous coefficients in the high-frequency regime. We show that the method is pollution-free also in the case of heterogeneous media provided that the stability bound of the continuous problem grows at most polynomially with the wave number k. By generalizing classical estimates of Melenk (Ph.D. Thesis, 1995) and Hetmaniuk (Commun. Math. Sci. 5, 2007) for homogeneous medium, we show that this assumption of polynomially wave number growth holds true for a particular class of smooth heterogeneous material coefficients. Further, we present numerical examples to verify our stability estimates and implement an example in the wider class of discontinuous coefficients to show computational applicability beyond our limited class of coefficients.
Optimized Schwarz methods have attracted tremendous attention because of their excellent performance. For circular domain decompositions, Gander and Xu (SIAM J. Numer. Anal. 52(4): 1981-2004, 2014;Math. Comput., 2016b...
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