Given a square matrix A, a Brauer's theorem [Brauer A., Limits for the characteristic roots of a matrix. IV. Applications to stochastic matrices, Duke Math. J., 1952, 19(1), 75-91] shows how to modify one single eigenvalue ...
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 ...
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 ...
Bru García, Rafael; Gasso Matoses, María Teresa; Santana-De Asis, Máximo De Jesús(Elsevier, 2022-01-01)
[EN] In this work, we study a lower bound of the condition number of a matrix by its combined matrix. In particular, we construct a special combined matrix in such a way that the sums of its columns are lower bounds of the ...
Bru García, Rafael; Gasso Matoses, María Teresa; Gimenez Manglano, María Isabel; Santana-De Asis, Máximo De Jesús(Elsevier, 2016-06-01)
The combined matrix of a nonsingular matrix A is the
Hadamard (entry wise) product C(A) = A ◦ (A−1)T . Since
each row and column sum of C(A) is equal to one, the combined
matrix is doubly stochastic when it is nonnegative. ...
Vallés Planells, María Concepción(Universitat Politècnica de València, 2014-06-19)
El paisaje puede dividirse en zonas o porciones con características homogéneas llamadas unidades de paisaje. Los aspectos que definen la homogeneidad de estas unidades dependen de la escala de análisis. Tradicionalmente, ...
Scott Guilleard, José Antonio(Universitat Politècnica de València, 2015-12-14)
[EN] The essential topic of this memory is the study of H-matrices as they
were introduced by Ostrowski and hereinafter extended and developed by
different authors. In this study three slopes are outlined: 1) the iterative ...
Bru García, Rafael; Gasso Matoses, María Teresa; Gimenez Manglano, María Isabel; Santana-De Asis, Máximo De Jesús(Taylor & Francis, 2017)
[EN] The combined matrix of a nonsingular matrix A is the Hadamard (entrywise) product . This paper deals with the characterization of the diagonal entries of a combined matrix C(A) of a given nonsingular real matrix A. A ...
[EN] The relationship among eigenvalues of a given square matrix A and the rank one updated matrix A+vkq⁎, where vk is an eigenvector of A associated with the eigenvalue λk and q is an arbitrary vector, was described ...
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, ...
In this work a technique to improve the condition number si of a simple eigenvalue lambda(i) of a matrix A is an element of C-nxn is given. This technique obtains a rank one updated matrix that is similar to A with the ...
Bru García, Rafael; Gimenez Manglano, María Isabel; Hadjidimos, Apostolos(Elsevier, 2012-01)
H-matrices play an important role in the theory and applications of Numerical Linear Algebra. So, it is very useful to know whether a given matrix A E Cn,n, usually the coefficient of a complex linear system of algebraic ...
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 ...
Santana de Asís, Máximo de Jesús(Universitat Politècnica de València, 2015-04-14)
[EN] Several authors have studied the Hadamard product or entry wise product of
two matrices with di erent objectives. In particular, the product of a Hadamard
matrix and the transpose of its inverse has proved useful in ...
Bru García, Rafael; Gasso Matoses, María Teresa; Gimenez Manglano, María Isabel; Santana, Maximo(Hindawi Publishing Corporation, 2014-04)
The combined matrix of a nonsingular real matrix 𝐴 is the Hadamard (entrywise) product 𝐴 ∘ (𝐴−1)
𝑇
. It is well known that row
(column) sums of combined matrices are constant and equal to one. Recently, some results ...
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.
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, ...
Bru García, Rafael; Gasso Matoses, María Teresa; Gimenez Manglano, María Isabel; Scott, José A.(Hindawi Publishing Corporation, 2015)
[EN] We study the combined matrix of a nonsingular H-matrix. Iese matrices can belong to two diRerent H-matrices classes: the most
common, invertible class, and one particular class named mixed class. DiRerent results ...
[EN] The European Landscape Convention has encouraged member states to develop tools for landscape planning and management. Landscape character assessment is the most widespread approach. The aim of this paper is to identify ...