Now showing items 1-20 of 111

• #### A canonical reduced form for singular time invariant linear systems ﻿

(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 ﻿

(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 ...
• #### Adjacency matrices of polarity graphs and of other C4-free graphs of large size ﻿

(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 ...
• #### A geometric approach to the Carlson problem ﻿

(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 ...
• #### Ajuste temporal de matrices OD basado en una aproximación del gradiente ﻿

(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 ﻿

(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, ...
• #### A matrix derivation of a representation theorem for (trAp)1/p ﻿

(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. ﻿

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 ...
• #### An Eigenvector pattern arising in non linear regression ﻿

(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 ...
• #### A new approach to the spectral excess theorem for distance-regular graphs ﻿

(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 ﻿

(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.
• #### Anticipating human activities from object interaction cues ﻿

(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, ...
• #### Aplicació informàtica per a la construcció de matrius polimèriques amorfes d'alta densitat ﻿

(Universitat Politècnica de Catalunya, 2018-01)
Bachelor thesis
Open Access
L’objectiu d’aquest projecte ha sigut iniciar el desenvolupament d’un programa que sigui capaç de construir matrius polimèriques amorfes d’alta densitat. Les matrius polimèriques poden estar compostes de cadenes molt ...
• #### Aplicaciones de la Teoría de Matrices en Matemática Discreta ﻿

(1999-07)
Working paper
Open Access
Se describen algunas aplicaciones de la teoría de matrices a diversos temas pertenecientes al ámbito de la matem\'atica discreta.
• #### Approaching dual quaternions from matrix algebra ﻿

(2014)
Article
Open Access
Dual quaternions give a neat and succinct way to encapsulate both translations and rotations into a unified representation that can easily be concatenated and interpolated. Unfortunately, the combination of quaternions and ...
• #### A Stein matrix equation related to transfer matrix of linear dynamic systems over commutative rings ﻿

(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 ﻿

(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 ﻿

(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 Volume Visualization Algorithm using a coherent Extended Weight Matrix ﻿

(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 ...
• #### Bounding the distance of a controllable and observable system to an uncontrollable or unobservable one ﻿

(1999)
Article
Open Access
Let $(A,B,C)$ be a triple of matrices representing a time-invariant linear system \left .\aligned \dot x(t)&=Ax(t)+Bu(t)\\y(t)&=Cx(t)\endaligned \right \} under similarity equivalence, corresponding to a realization ...