López Alfonso, Salvador; López-Pellicer, Manuel; Mas Marí, José(Yılmaz Simsek, 2021)
[EN] Let ba(A) be the Banach space of the real (or complex) finitely additive measures of bounded variation defined on an algebra A of subsets of Omega and endowed with the variation norm. . A subset B of A is a Nikod ́ym ...
[EN] Computational electromagnetics based on the solution of the integral form of Maxwell s
equations with boundary element methods require the solution of large and dense linear
systems. For large-scale problems the ...
Bru, Rafael; Mas Marí, José; Urbano Salvador, Ana María(Society for Industrial and Applied Mathematics, 1994)
[EN] B. N. Datta and K. Datta have proposed an efficient parallel algorithm for the single-input pole
assignment problem when the spectrum set to be assigned is pairwise distinct and disjoint from the spectrum
of the ...
[EN] An approximate inverse LU preconditioner is constructed based on the Sherman-Morrison formula. Applying recursively that inversion formula a multiplicative decomposition of the inverse of a matrix is obtained. This ...
[EN] We consider the numerical solution of linear systems arising from computational electromagnetics applications. For large scale problems the solution is usually obtained iteratively with a Krylov subspace method. It ...
Marín Mateos-Aparicio, José; Mas Marí, José(Springer-Verlag, 2023-01)
[EN] In this work we study pivoting strategies for the preconditioner presented in Bru (SIAM J Sci Comput 30(5):2302-2318, 2008) which computes the LU factorization of a matrix A. This preconditioner is based on the Inverse ...
Cerdán Soriano, Juana Mercedes; Faraj El Guelei, Táher; Malla Martínez, Natalia; Marín Mateos-Aparicio, José; Mas Marí, José(KENT STATE UNIVERSITY, ETNA, DEPT MATHEMATICS & COMPUTER SCIENCE, KENT, USA, OH, 44242-0001, 2010)
[EN] In this paper block approximate inverse preconditioners to solve sparse nonsymmetric linear systems
with iterative Krylov subspace methods are studied. The computation of the preconditioners involves consecutive
updates ...
Bru, R.; Corral Ortega, Cristina; Gimenez Manglano, María Isabel; Mas Marí, José(Elsevier, 2008)
[EN] Let M(A) denote the comparison matrix of a square H-matrix A, that is, M(A) is an M-matrix. H-matrices such that their comparison matrices are non-singular are well studied in the literature. In this paper, we study ...
López Alfonso, Salvador(Universitat Politècnica de València, 2016-12-16)
The classical Nykodym theorem (1933) asserts that a set H of countably additive complex measures defined on a sigma-algebra S which is bounded for each element of S, then H is uniformly bounded on S. It is well known that ...
Bru García, Rafael; Marín Mateos-Aparicio, José; Mas Marí, José; Tuma, Miroslav(Society for Industrial and Applied Mathematics, 2010)
[EN] . In this paper we improve the BIF algorithm which computes simultaneously the LU
factors (direct factors) of a given matrix and their inverses (inverse factors). This algorithm was
introduced in [R. Bru, J. Mar´ın, ...
Preconditioners for the Conjugate Gradient method are studied to solve the Newton system with symmetric positive definite (SPD) Jacobian. Following the theoretical work in Bergamaschi et al. (2011) [4] we start from a given ...
[EN] Let Ax = b be a large and sparse system of linear equations where A is a nonsingular matrix. An approximate solution is frequently obtained by applying preconditioned terations. Consider the matrix B = A + PQT where ...
López Alfonso, Salvador; Mas Marí, José; Moll López, Santiago Emmanuel(Springer-Verlag, 2016)
[EN] A subset B of an algebra A of subsets of Omega is said to have property N if a
B-pointwise bounded subset M of ba(A ) is uniformly bounded on A , where ba(A ) is
the Banach space of the real (or complex) finitely ...
Guerrero Flores, Danny Joel(Universitat Politècnica de València, 2018-07-02)
El tema principal de esta tesis es el desarrollo de técnicas de actualización de precondicionadores para resolver sistemas lineales de gran tamaño y dispersos Ax=b mediante el uso de métodos iterativos de Krylov. Se ...
Mas Marí, José; Marín Mateos-Aparicio, José(Universitat Politècnica de València, 2022-07-15)
[EN] In this work we study pivoting strategies for the preconditioner presented Balanced Incomplete Preconditioner (SIAM J
Sci Comput 30(5):2302¿2318, 2008) which computes the LU factorization of a matrix A. We present a ...
Bru García, Rafael; Marín Mateos-Aparicio, José; Mas Marí, José; Tuma, Miroslav(Society for Industrial and Applied Mathematics, 2014)
New preconditioning strategies for solving m × n overdetermined large and sparse
linear least squares problems using the conjugate gradient for least squares (CGLS) method are
described. First, direct preconditioning of ...
In this paper we survey our work on preconditioners based on the
Inverse Sherman-Morrison factorization. The most important theoretical results are also summarized and some numerical conclusions are provided.
Cerdán Soriano, Juana Mercedes; Guerrero-Flores, Danny Joel; Marín Mateos-Aparicio, José; Mas Marí, José(Elsevier, 2018-12-01)
[EN] We present a preconditioning technique for solving nonsymmetric linear systems Ax = b, where the coefficient matrix A has a skew-symmetric part that can be well approximated with a skew-symmetric low-rank matrix. The ...
[EN] In this paper we present a method for computing sparse preconditioners for iteratively solving rank deficient least squares problems (LS) by the LSMR method. The main idea of the method proposed is to update an ...
Bru García, Rafael; Corral Ortega, Cristina; Gimenez Manglano, María Isabel; Mas Marí, José(John Wiley & Sons, 2009)
[EN] It is well known that the Schur complement of some H-matrices is an H-matrix. In this paper, the Schur complement of any general H-matrix is studied. In particular, it is proved that the Schur complement, if it exists, ...