Now showing items 1-20 of 144

    • A canonical reduced form for singular time invariant linear systems 

      García Planas, María Isabel; Díaz, Adolfo (2009-09)
      Conference report
      Open Access
      We consider quadruples of matrices (E; A;B;C), representing singular linear time invariant systems in the form Ex_ (t) = Ax + Bu y = Cx ¾ (1) with E;A 2 Mp£n(C), B 2 Mp£m(C) and C 2 Mq£n(C) under proportional and ...
    • A construction of small regular bipartite graphs of girth 8 

      Balbuena Martínez, Maria Camino Teófila (2009-01)
      Article
      Open Access
      Let q be a prime a power and k an integer such that 3 ≤ k ≤ q. In this paper we present a method using Latin squares to construct adjacency matrices of k-regular bipartite graphs of girth 8 on $2(kq^{2}-q)$ vertices. Some ...
    • A design procedure for overlapped guaranteed cost controllers 

      Palacios Quiñonero, Francisco; Rodellar Benedé, José; Rossell Garriga, Josep Maria (Elsevier, 2008)
      Conference lecture
      Open Access
      In this paper a quadratic guaranteed cost control problem for a class of linear continuous-time state-delay systems with norm-bounded uncertainties is considered. We will suppose that the systems are composed by two ...
    • A geometric approach to the Carlson problem 

      Compta Creus, Albert; Ferrer Llop, Josep (Society for Industrial and Applied Mathematics (Filadèlfia), 2000)
      Article
      Open Access
      The possible observability indices of an observable pair of matrices, when supplementary subpairs are prescribed, are characterized when the “quotient” one is nilpotent. The geometric techniques used are also valid in the ...
    • A matrix derivation of a representation theorem for (trAp)1/p 

      Neudecker, Heinz (Universitat Politècnica de Catalunya. Centre de Càlcul, 1989)
      Article
      Open Access
      A matrix derivation of a well-known representation theorem for (tr Ap)1/p is given, which is the solution of a restricted maximization problem. The paper further gives a solution of the corresponding restricted minimization ...
    • A matrix function useful in the estimation of linear continuous-time models. 

      Neudecker, Heinz (Institut d'Estadística de Catalunya, 2006)
      Article
      Open Access
      In a recent publication Chen & Zadrozny (2001) derive some equations for efficiently computing eA and ∇ eA, its derivative. They employ an expression due to Bellman (1960), Snider (1964) and Wilcox (1967) for the differential ...
    • A new approach to the spectral excess theorem for distance-regular graphs 

      Fiol Mora, Miquel Àngel; Gago Álvarez, Silvia; Garriga Valle, Ernest (2009-04-01)
      Article
      Open Access
      The Spectral Excess Theorem provides a quasi-spectral characterization for a (regular) graph $\Gamma$ with $d+1$ different eigenvalues to be distance-regular graph, in terms of the mean (d-1)-excess of its vertices.\ The ...
    • A new proof of the Milliken-Akdeniz theorem 

      Neudecker, Heinz (Universitat Politècnica de Catalunya. Centre de Càlcul, 1989)
      Article
      Open Access
      A simple proof is given for a theorem by Milliken and Akdeniz (1977) about the difference of the Moore-Penrose inverses of two positive semi-definite matrices.
    • A Stein matrix equation related to transfer matrix of linear dynamic systems over commutative rings 

      García Planas, María Isabel; Lopez Cabeceira, Montserrat (Editorial de la Universitat Politècnica de València (UPV), 2010)
      Conference report
      Open Access
      Este trabajo está inmerso en el campo de la Teoría de Control sobre un anillo conmutativo R con elemento unidad. Dado un sistema dinámico lineal invariante en el tiempo representado por x+(t) = Ax(t) + Bu(t) sobre R, ...
    • A study of QR decomposition and Kalman filter implementations 

      Fuertes Roncero, David (Universitat Politècnica de Catalunya, 2014-09)
      Master thesis (pre-Bologna period)
      Open Access
      Covenantee:   Kungliga Tekniska högskolan
      [ANGLÈS] With the rapid development of new technologies during the last decades, the demand of complex algorithms to work in real-time applications has increased considerably. To achieve the real time expectations and to ...
    • A survey on the missing Moore graph 

      Dalfó Simó, Cristina (Elsevier, 2019)
      Article
      Open Access
      This is a survey on some known properties of the possible Moore graph (or graphs) ¿ with degree 57 and diameter 2. Moreover, we give some new results about it, such as the following. When we consider the distance partition ...
    • A variational solution of the time-dependent Schrodinger equation by a restricted superposition of frozen Gaussian wavepackets 

      Zoppe, Justin Orazio; Parkinson, Meredith L.; Messina, Michael (2005-05)
      Article
      Restricted access - publisher's policy
      We present a variational solution of the time-dependent Schrodinger equation formed from a restricted superposition of frozen Gaussian wavepackets. The trial function is comprised of a set of frozen Gaussian wavepackets ...
    • A Volume Visualization Algorithm using a coherent Extended Weight Matrix 

      Tost Pardell, Daniela; Puig Puig, Anna; Navazo Álvaro, Isabel (1995-01)
      Article
      Restricted access - publisher's policy
      Direct cell-to-cell volume visualization algorithms, also called projective rendering methods, present the advantage of allowing semi-transparencies and, additionally, as they project all the samples, they avoid the ...
    • Adjacency matrices of polarity graphs and of other C4-free graphs of large size 

      Abreu, M.; Balbuena Martínez, Maria Camino Teófila; Labbate, D. (2010)
      Article
      Restricted access - publisher's policy
      In this paper we give a method for obtaining the adjacency matrix of a simple polarity graph $G_q$ from a projective plane PG(2,q), where q is a prime power. Denote by ex(n;C₄) the maximum number of edges of a graph on n ...
    • Ajuste temporal de matrices OD basado en una aproximación del gradiente 

      Bullejos González, Manuel (Universitat Politècnica de Catalunya, 2013-02)
      Master thesis
      Open Access
      Modelar la demanda del transporte en función de una matriz Origen-Destino (OD) es un aspecto clave en casi todos los modelos de transporte. Cuando realizamos una planificación estratégica del transporte hacemos uso de ...
    • Alternative tests for functional and pointwise output-controllability of linear time-invariant systems 

      García Planas, María Isabel; Domínguez García, José Luís (2013)
      Article
      Open Access
      This paper deals with the description of a new method for calculating the functional output-controllability. It is computed by means of the rank of a certain constant matrix which can be associated to the system. Moreover, ...
    • An Eigenvector pattern arising in non linear regression 

      Cuadras, C.M. (Carlos Maria) (Universitat Politècnica de Catalunya. Centre de Càlcul, 1990)
      Article
      Open Access
      Let A = (aij) be an n x n matrix defined by aij = aji = i, i = 1,...,n. This paper gives some elementary properties of A and other related matrices. The eigenstructure of A is conjectured: given an eigenvector v of A the ...
    • An iterative linear matrix inequality controller-design strategy for H-infinity structural vibration control 

      Palacios Quiñonero, Francisco; Rubió Massegú, Josep; Rossell Garriga, Josep Maria; Reza Karimi, Hamid (CRC Press/Balkema, 2019)
      Conference report
      Open Access
      In this paper, we present a novel Iterative Linear Inequality (ILMI) strategy for controller design that makes it possible to compute suboptimal H-infinity static output-feedback (SOF) controllers with high-performance ...
    • An open set of 4×4 embeddable matrices whose principal logarithm is not a Markov generator 

      Casanellas Rius, Marta; Fernández Sánchez, Jesús; Roca Lacostena, Jordi (Taylor & Francis, 2020-12-17)
      Article
      Open Access
      A Markov matrix is embeddable if it can represent a homogeneous continuous-time Markov process. It is well known that if a Markov matrix has real and pairwise-different eigenvalues, then the embeddability can be determined ...
    • Anticipating human activities from object interaction cues 

      Aranda López, Juan; Vinagre Ruiz, Manuel (Institute of Electrical and Electronics Engineers (IEEE), 2016)
      Conference report
      Restricted access - publisher's policy
      A real time approach to the recognition of human activity based on the interaction with objects in domestic settings is presented. It is based on capturing partial images where the activity takes place using a color camera, ...