Precondicionamiento de sistemas de ecuaciones de matrices variables en la modelización de campos de viento

Eliminadas las páginas en blanco del pdf

Normalized Frobenius condition number of the orthogonal projections of the identity

[EN]This paper deals with the orthogonal projection (in the Frobenius sense) AN of the identity matrix I onto the matrix subspace AS (A ? Rn×n, S being an arbitrary subspace of Rn×n). Lower and upper bounds on the normalized Frobenius condition number of matrix AN are given. Furthermore, for every matrix subspace S ? Rn×n, a new index bF (A, S), which generalizes the normalized Frobenius condition number of matrix A, is defined and analyzed...

Improving approximate inverses based on Frobenius norm minimization

[EN]Approximate inverses, based on Frobenius norm minimization, of real nonsingular matrices are analyzed from a purely theoretical point of view. In this context, this paper provides several sufficient conditions, that assure us the possibility of improving (in the sense of the Frobenius norm) some given approximate inverses. Moreover, the optimal approximate inverses of matrix A ∈ R n×n , among all matrices belonging to certain subspaces of R n×n , are obtained. Particularly, a natural generalization of the classical normal equations of the system Ax = b is given, when searching for approximate inverses N 6= AT such that AN is symmetric and kAN − IkF < AAT − I F …

A generalization of the optimal diagonal approximate inverse preconditioner

[EN ]The classical optimal (in the Frobenius sense) diagonal preconditioner for large sparse linear systems Ax = b is generalized and improved. The new proposed approximate inverse preconditioner N is based on the minimization of the Frobenius norm of the residual matrix AM − I, where M runs over a certain linear subspace of n × n real matrices, defined by a prescribed sparsity pattern. The number of nonzero entries of the n×n preconditioning matrix N is less than or equal to 2n, and n of them are selected as the optimal positions in each of the n columns of matrix N. All theoretical results are justified in detail…

The meccano method for automatic 3-d triangulation and volume parametrization of complex solids

[EN]In this paper we review the novel meccano method. We summarize the main stages (subdivision, mapping, optimization) of this automatic tetrahedral mesh generation technique and we concentrate the study to complex genus-zero solids. In this case, our procedure only requires a surface triangulation of the solid. A crucial consequence of our method is the volume parametrization of the solid to a cube. We construct volume T-meshes for isogeometric analysis by using this result. The efficiency of the proposed technique is shown with several examples. A comparison between the meccano method and standard mesh generation techniques is introduced.-1…

Los cimientos del Plan de Manejo del Parque de la Minería (Lucainena de las Torres, Almería) : Las matrices de formato Marco Lógico de la vehiculación

[ES]Para el marco geográfico de Lucainena de las Torres (Almería, España), se han formulado los cimientos del previsible Parque de la Minería. Estos se apoyan en el diseño de matrices bajo formato Marco Lógico, que satisfacen a los itinerarios de objetivos de la vehiculación generada al efecto. Se han obtenido 478 matrices, que recogen 3094 actuaciones de 151 planteamientos distribuidos entre 54 propuestas, que dan cuerpo a los 8 proyectos del Plan de Manejo. La temporalización del conjunto del Plan de Manejo recoge un proyecto inicial a modo de análisis de la viabilidad del Parque de la Minería, un bloque central de proyectos en transversalidad y un último proyecto relativo a la promoción del espacio protegido.