On approximate inverse systems and resolutions
نویسندگان
چکیده
منابع مشابه
On approximate inverse systems and resolutions
Recently, L. R. Rubin, T. Watanabe and the author have introduced approximate inverse systems and approximate resolutions, a new tool designed to study topological spaces. These systems differ from the usual inverse systems in that the bonding maps paa′ are not subject to the commutativity requirement paa′pa′a′′ = paa′′ , a ≤ a′ ≤ a′′. Instead, the mappings paa′pa′a′′ and paa′′ are allowed to d...
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Parallel normalized preconditioned conjugate gradient type methods based on normalized approximate finite element inverse matrix techniques are investigated for the efficient solution of sparse linear systems. Application of the proposed methods on a three dimensional boundary value problems is discussed and numerical results are given. The parallel implementation of the normalized precondition...
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In this paper we consider the problem of preconditioning symmetric positive definite matrices of the form Aα = A+αI where α > 0. We discuss how to cheaply modify an existing sparse approximate inverse preconditioner for A in order to obtain a preconditioner for Aα. Numerical experiments illustrating the performance of the proposed approaches are presented. AMS subject classification (2000): 65F...
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RAL 95 - 026 On approximate - inverse preconditioners
We investigate the use of sparse approximate-inverse preconditioners for the iterative solution of unsymmetric linear systems of equations. Such methods are of particular interest because of the considerable scope for parallelization. We propose a number of enhancements which may improve their performance. When run in a sequential environment, these methods can perform unfavourably when compare...
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ژورنال
عنوان ژورنال: Fundamenta Mathematicae
سال: 1993
ISSN: 0016-2736,1730-6329
DOI: 10.4064/fm-142-3-241-255