Now showing items 21-40 of 493

  • Algebraic characteritzacions of bipartite distance-regular graphs 

    Fiol, Miquel Àngel (2010-06-10)
    Audiovisual
    Open Access
  • Algebraic characterizations of bipartite distance-regular graphs 

    Fiol Mora, Miquel Àngel (Iniciativa Digital Politècnica, 2011)
    Conference report
    Open Access
    Bipartite graphs are combinatorial objects bearing some interesting symmetries. Thus, their spectra—eigenvalues of its adjacency matrix—are symmetric about zero, as the corresponding eigenvectors come into pairs. Moreover, ...
  • Algebraic characterizations of distance-regular graphs 

    Fiol Mora, Miquel Àngel (Elsevier, 2002)
    Article
    Open Access
    We survey some old and some new characterizations of distance-regular graphs, which depend on information retrieved from their adjacency matrix. In particular, it is shown that a regular graph with d+1 distinct eigenvalues ...
  • Algebraic Characterizations of Regularity Properties in Bipartite Graphs 

    Abiad Monge, Aida; Dalfó Simó, Cristina; Fiol Mora, Miquel Àngel (2013)
    Article
    Restricted access - publisher's policy
    Regular and distance-regular characterizations of general graphs are well-known. In particular, the spectral excess theorem states that a connected graph GG is distance-regular if and only if its spectral excess (a number ...
  • Algorithms for the linear coloring arrangement problem 

    Sánchez Barrera, Isaac (Universitat Politècnica de Catalunya, 2015-01-28)
    Bachelor thesis
    Open Access
    [CATALÀ] El projecte emprèn la tasca de desenvolupar algorismes eficients per resoldre o aproximar el problema de l'arranjament lineal mínim d'una coloració per a graphs, variació del MinLA. Aquí, l'assignació lineal està ...
  • Algorithms for the restricted linear coloring arrangement problem 

    Llop Palao, Joan (Universitat Politècnica de Catalunya, 2019-07-04)
    Bachelor thesis
    Open Access
    The aim of this project is to develop efficient algorithms for solving or approximating the Minimum Restricted Linear Coloring Arrangement Problem. It is the first approach to its algorithms, and we will face the problem ...
  • Algorithms for the weighted independent domination problem 

    Rodríguez Corominas, Guillem (Universitat Politècnica de Catalunya, 2019-07-04)
    Bachelor thesis
    Open Access
    El problema de la dominació independent ponderada és un problema NP-hard d'optimització combinatòria en grafs. Aquest problema només ha estat abordat a la literatura per enfocaments de programació lineal entera, heurístiques ...
  • Algunos grafos compuestos 

    Fiol Mora, Miquel Àngel; Fàbrega Canudas, José (Universidad de Barcelona, Departamento de Estadística Matemática;Universidad Politécnica de Barcelona, Escuela Técnica Superior de Arquitectura, Departamento de Matemáticas y Estadística, 1983)
    Article
    Open Access
    From two graphs $G_1$ and $G_2$ on $N_1$ and $N_2$ vertices respectively, the compound graph $G_1[G_2]$ on $N_1N_2$ vertices is obtained connecting $N_2$ copies of $G_1$ following the structure of $G_2$. We present in ...
  • Almost every tree with m edges decomposes K2m,2m 

    Drmota, Michael; Lladó Sánchez, Ana M. (2014-01)
    Article
    Open Access
    We show that asymptotically almost surely a tree with m edges decomposes the complete bipartite graph K2m,2m, a result connected to a conjecture of Graham and Häggkvist. The result also implies that asymptotically almost ...
  • A logic of graph conditions extended with paths 

    Navarro Gomez, Marisa; Orejas Valdés, Fernando; Pino Blanco, Elvira; Lambers, Leen (2016)
    Conference report
    Open Access
    In this paper we tackle the problem of extending the logic of nested graph conditions with paths. This means, for instance, that we may state properties about the existence of paths between some given nodes. As a main ...
  • A logic of graph conditions extended with paths 

    Navarro Gomez, Marisa; Orejas Valdés, Fernando; Pino Blanco, Elvira; Lambers, Leen (2016)
    Conference report
    Open Access
    In this paper we tackle the problem of extending the logic of nested graph conditions with paths. This means, for instance, that we may state properties about the existence of paths between some given nodes. As a main ...
  • A mathematical model for dynamic memory networks 

    Fàbrega Canudas, José; Fiol Mora, Miquel Àngel; Serra Albó, Oriol; Andrés Yebra, José Luis (Iniciativa Digital Politècnica, 2011)
    Conference report
    Open Access
    The aim of this paper is to bring together the work done several years ago by M.A. Fiol and the other authors to formulate a quite general mathematical model for a kind of permutation networks known as dynamic memories. A ...
  • An algebraic approach to lifts of digraphs 

    Dalfó Simó, Cristina; Fiol Mora, Miquel Àngel; Miller, Mirka; Ryan, Joe; Siran, Josef (2018-12-07)
    Article
    Open Access
    We study the relationship between two key concepts in the theory of (di)graphs: the quotient digraph, and the lift Ga of a base (voltage) digraph. These techniques contract or expand a given digraph in order to study its ...
  • Anàlisi i similitud d'articles acadèmics utilitzant tècniques de llenguatge natural i xarxes neuronals 

    Botet Colomer, Marc (Universitat Politècnica de Catalunya, 2019-01)
    Bachelor thesis
    Open Access
    This project has reviewed the state of the art in natural language processing in order to extract the similarity between academic papers. In addition, analysis tools have been added in order to study the evolution of the ...
  • Analysis of LDPC code syndrome entropy based on subgraphs 

    Matas Navarro, David; Lamarca Orozco, M. Meritxell (Institute of Electrical and Electronics Engineers (IEEE), 2016)
    Conference report
    Restricted access - publisher's policy
    We propose a method to bound the syndrome entropy of linear block codes from their factor graph representation. It is specially suited for sparse graphs such as those of low density parity check codes. It is based on the ...
  • Analysis of Network Algorithms 

    Mamano Grande, Nil (Universitat Politècnica de Catalunya, 2015-06)
    Bachelor thesis
    Restricted access - confidentiality agreement
    Covenantee:  University of California, Irvine
  • Analysis on distance metrics approaches in graphs and their applications 

    Cebollero Ruiz, Laura (Universitat Politècnica de Catalunya, 2019-07-05)
    Master thesis
    Restricted access - confidentiality agreement
  • An eigenvalue characterization of antipodal distance-regular graphs 

    Fiol Mora, Miquel Àngel (1997-11)
    Article
    Open Access
    Let $\Gamma$ be a regular (connected) graph with $n$ vertices and $d+1$ distinct eigenvalues. As a main result, it is shown that $\Gamma$ is an $r$-antipodal distance-regular graph if and only if the distance graph $\Gamma_d$ ...
  • A new application of the $\otimes_h$-product to $\alpha$-labelings 

    López Masip, Susana Clara; Muntaner Batle, Francesc Antoni (2015)
    Article
    Open Access
    The weak tensor product was introduced by Snevily as a way to construct new graphs that admit a-labelings from a pair of known a-graphs. In this article, we show that this product and the application to a-labelings can be ...
  • A new approach to gross error detection for GPS networks 

    Dalfó Simó, Cristina; Fiol Mora, Miquel Àngel (2019-05-29)
    Article
    Open Access
    We present a new matrix-based approach to detect and correct gross errors in GPS geodetic control networks. The study is carried out by introducing a new matrix, whose entries are powers of a (real or complex) variable, ...