Now showing items 21-40 of 108

  • Bounding the distance of a controllable system to an uncontrollable one 

    Clotet Juan, Josep; García Planas, María Isabel (1998)
    Article
    Open Access
    Let $(A,B)$ be a pair of matrices representing a time-invariant linear system $\dot x(t)=Ax(t)+Bu(t)$ under block-similarity equivalence. In this paper we measure the distance between a controllable pair of matrices ...
  • Characterization of symmetric M-matrices as resistive inverses 

    Bendito Pérez, Enrique; Carmona Mejías, Ángeles; Encinas Bachiller, Andrés Marcos; Gesto Beiroa, José Manuel (2007-01-25)
    Article
    Open Access
    We aim here at characterizing those nonnegative matrices whose inverse is an irreducible Stieltjes matrix. Specifically, we prove that any irreducible Stieltjes matrix is a resistive inverse. To do that we consider the ...
  • Combinatorial recurrences and linear difference equations 

    Jiménez Jiménez, María José; Encinas Bachiller, Andrés Marcos (2016-10-17)
    Article
    Open Access
    In this work we introduce the triangular arrays of depth greater than 1 given by linear recurrences, that generalize some well known recurrences that appear in enumerative combinatorics. In particular, we focussed on ...
  • Combinatorial recurrences and linear difference equations 

    Jiménez Jiménez, María José; Encinas Bachiller, Andrés Marcos (2016)
    Conference report
    Restricted access - publisher's policy
    In this work we introduce the triangular arrays of depth greater than 1 given by linear recurrences, that generalize some well-known recurrences that appear in enumerative combinatorics. In particular, we focussed on ...
  • Computing size-independent matrix problems on systolic array processors 

    Navarro Guerrero, Juan José; Llaberia Griñó, José M.; Valero Cortés, Mateo (Institute of Electrical and Electronics Engineers (IEEE), 1986)
    Conference report
    Open Access
    A methodology to transform dense to band matrices is presented in this paper. This transformation, is accomplished by triangular blocks partitioning, and allows the implementation of solutions to problems with any given ...
  • Controllability of $\ell$-order linear systems 

    García Planas, María Isabel (2003)
    Article
    Open Access
    Given a (` + 1)-ple of matrices (A`¡1; : : : ;A0;B) representing `- order time-invariant linear systems, x(`) = A`¡1x(`¡1) + : : : + A0x(0) + Bu, we analyze conditions in such a way that changing the control u by u1 = u ...
  • Deformaciones miniversales de parejas de tensores de segundo orden 

    Clotet Juan, Josep; Magret Planas, Maria dels Dolors; Peña Carrera, Marta (Universidad de Sevilla, 2007-09)
    Conference report
    Open Access
    Consideramos en el espacio de parejas de tensores tension y deformacion la relacion de equivalencia que se corresponde con cambios de base ortonormales. Identificandolas con parejas de matrices cuadradas, podemos utilizar ...
  • Description of characteristic non-hyperinvariant subspaces over the field GF(2) 

    Mingueza, David; Montoro López, María Eulalia; Pacha Andújar, Juan Ramón (Elsevier, 2013-10-26)
    Article
    Restricted access - publisher's policy
    Given a square matrix A, an A-invariant subspace is called hyperinvariant (respectively, characteristic) if and only if it is also invariant for all matrices T (respectively, nonsingular matrices T) that commute with A. ...
  • Dimension of the orbit of marked subspaces 

    Compta Creus, Albert; Ferrer Llop, Josep; Peña Carrera, Marta (2004)
    Article
    Open Access
    Given a nilpotent endomorphism, we consider the manifold of invariant subspaces having a fixed Segre characteristic. In [Linear Algebra Appl., 332–334 (2001) 569], the implicit form of a miniversal deformation of an ...
  • Diseño y cálculo de una matriz progresiva para realizar una garra pasacables por estampación en frío 

    Mariné Arce, Alberto (Universitat Politècnica de Catalunya, 2012-02)
    Master thesis (pre-Bologna period)
    Open Access
    Se trata de realizar el diseño y cálculo de una matriz progresiva de 9 estaciones o pasos con el fin de obtener una garra metálica pasa cables. El plano de la pieza viene definido por el cliente, lo que nos definirá que ...
  • Diseño y programación de una matriz de leds en forma de cubo 

    Garcia Sanchez, Paula (Universitat Politècnica de Catalunya, 2012-02)
    Master thesis (pre-Bologna period)
    Open Access
    Este proyecto trata del diseño y de la programación de una matriz de leds en forma de cubo. Para llevar a cabo este proyecto ha sido necesario realizar un estudio de los diferentes micro controladores PIC existentes en ...
  • Eigenvalues and eigenvectors of monomial matrices 

    García Planas, María Isabel; Magret Planas, Maria dels Dolors (Universidad de Cádiz, 2015)
    Conference report
    Open Access
    Spectral properties of special matrices matrices have been widely applied. We focus on monomial matrices over a finite field $F_{p}$, $p \neq 2$. We describe a way to find the minimal annihilating polynomial, a set of ...
  • El problema dels ponts de Köningsberg: idees per a l’aula 

    López Beltrán, Mireia (Edicions de la Universitat de Barcelona, 2014-06)
    Article
    Open Access
    Aprofitem el problema dels ponts de Köningsberg per plantejar a l’alumnat una situació contextualitzada que ens permet treballar diferents aspectes, curriculars o no, de les matemàtiques. A més, seguint directament el fil ...
  • Emergent Group Properties in Financial Markets 

    Doria Arrieta, Omar Alonso (Universitat Politècnica de Catalunya, 2011-06-17)
    Master thesis
    Open Access
    In the present we have analyzed the data from 480 companies of the S&P500 using the Random Matrix Theory and the Inverse Participation Ratio, we analyzed the eigenvalues and its respective eigenvectors in order to find ...
  • Estimation of the noncentrality matrix of a noncentral Wishart distribution with unit scale matrix. A matrix generalitzation of Lenng's domination result 

    Neudecker, Heinz (Institut d'Estadística de Catalunya, 2004)
    Article
    Open Access
    The main aim is to estimate the noncentrality matrix of a noncentral Wishart distribution. The method used is Leung’s but generalized to a matrix loss function. Parallelly Leung’s scalar noncentral Wishart identity is ...
  • Estudio de la influencia de diversos factores sobre el tiempo de giro de una peonza, mediante el uso de experimentos factoriales a dos niveles 

    Riera Antonio, Juan; Torres Planells, Joan Antoni 1946- (Universitat Politècnica de Barcelona. Centre de Càlcul, 1991)
    Article
    Open Access
    Este estudio surge como respuesta a un ejercicio propuesto por la Cátedra de Estadística de la E.T.S.E.I.B. Nuestra propuesta consiste en aplicar el método de los diseños factoriales de experimentos a dos niveles, ensayando ...
  • Estudio y evaluación de eficiencia de operaciones con matrices dispersas (sparse) en sistemas distribuidos 

    Raimbaud, Pierre (Universitat Politècnica de Catalunya, 2014-06-20)
    Bachelor thesis
    Open Access
    [CASTELLÀ] El objetivo de ese proyecto es estudiar y evaluar, en sistemas distribuidos, la eficiencia de operaciones con matrices dispersas (sparse), sabiendo la forma en la cual están almacenadas y los algoritmos usados, ...
  • Explicit inverse of nonsingular Jacobi matrices 

    Encinas Bachiller, Andrés Marcos; Jiménez Jiménez, María José (2019-03-22)
    Article
    Restricted access - publisher's policy
    We present here the necessary and sufficient conditions for the invertibility of tridiagonal matrices, commonly named Jacobi matrices, and explicitly compute their inverse. The techniques we use are related with the solution ...
  • Factorization of the transfer matrix of a singular linear systems 

    García Planas, María Isabel; López Cabeceira, M. Montserrat (IPACS Electrinic Library, 2011)
    Part of book or chapter of book
    Restricted access - publisher's policy
    Given a linear dynamic time invariant represented by x + ( t ) = Ax ( t ) Bu ( t ) , y ( t ) = Cx ( t ) , we analyze con- ditions for obtention of a coprime factorization of trans- fer matrices of ...
  • From subkautz digraphs to cyclic kautz digraphs 

    Dalfó Simó, Cristina (2018-06-01)
    Article
    Open Access
    Kautz digraphs K(d,l) are a well-known family of dense digraphs, widely studied as a good model for interconnection networks. Closely related with these, the cyclic Kautz digraphs CK(d,l) were recently introduced by Böhmová, ...