Ara es mostren els items 1-20 de 36

    • A fast and efficient algorithm to identify clusters in networks 

      Comellas Padró, Francesc de Paula; Miralles de la Asunción, Alicia (2008-08-02)
      Article
      Accés obert
      A characteristic feature of many relevant real life networks, like the WWW, Internet, transportation and communication networks, or even biological and social networks, is their clustering structure. We discuss in this ...
    • Activities and coefficients of the Tutte polynomial 

      Hakim, Sahar (Universitat Politècnica de Catalunya, 2019-01)
      Projecte Final de Màster Oficial
      Accés obert
      Matroids are combinatorial objects that capture abstractly the essence of dependence. The Tutte polynomial, defined for matroids and graphs, has a numerous amount of information about these structures. In this thesis, we ...
    • Additive volume of sets contained in few arithmetic progressions 

      Freiman, Gregory A.; Serra Albó, Oriol; Spiegel, Christoph (De Gruyter, 2019-03-06)
      Article
      Accés obert
      A conjecture of Freiman gives an exact formula for the largest volume of a finite set A of integers with given cardinality k=|A| and doubling T=|2A|. The formula is known to hold when T=3k-4, for some small range over 3k-4 ...
    • An eigenvalue characterization of antipodal distance-regular graphs 

      Fiol Mora, Miquel Àngel (1997-11)
      Article
      Accés obert
      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 $\Gamma_d$ ...
    • Bounded expansion in models of webgraphs 

      Gago Álvarez, Silvia; Schlatter, Dirk (2007-10-02)
      Article
      Accés obert
      We study the bounded expansion of several models of web graphs. We show that various deterministic graph models for large complex networks have constant bounded expansion.We study two random models of webgraphs, showing ...
    • Bumblebees: a multiagent combinatorial optimization algorithm inspired by social insect behaviour 

      Comellas Padró, Francesc de Paula; Martínez Navarro, Jesús (2009-01-20)
      Comunicació de congrés
      Accés obert
      This paper introduces a multiagent optimization algorithm inspired by the collective behavior of social insects. In our method, each agent encodes a possible solution of the problem to solve, and evolves in a way similar ...
    • Characterizing (l,m)-walk-regularity 

      Dalfó Simó, Cristina; Fiol Mora, Miquel Àngel; Garriga Valle, Ernest (2009-05)
      Article
      Accés obert
      A graph $\G$ with diameter $D$ and $d+1$ distinct eigenvalues is said to be {\it $(\ell,m)$-walk-regular}, for some integers $\ell\in[0,d]$ and $m\in[0,D]$, $\ell\ge m$, if the number of walks of length $i\in [0,\ell]$ ...
    • Combinatorial artists: counting, permutations, and other discrete structures in art 

      Barrière Figueroa, Eulalia (Springer, 2021)
      Capítol de llibre
      Accés obert
      This chapter is motivated by a question I asked myself: “How can combinatorial structures be used in a work of art?” Immediately, other questions arose: Are there artists that work or think combinatorially? If so, what ...
    • Combinatorial vs. algebraic characterizations of pseudo-distance-regularity around a set 

      Cámara Vallejo, Marc; Fàbrega Canudas, José; Fiol Mora, Miquel Àngel; Garriga Valle, Ernest (2009-06)
      Report de recerca
      Accés obert
      Given a simple connected graph $\Gamma$ and a subset of its vertices $C$, the pseudo-distance-regularity around $C$ generalizes, for not necessarily regular graphs, the notion of completely regular code. Up to now, most ...
    • Combinatòria d'escales musicals i acords 

      García Herrera, Alejandro (Universitat Politècnica de Catalunya, 2021-05)
      Treball Final de Grau
      Accés obert
      En aquest treball es realitza un estudi de diferents conjunts i successions de notes musicals, com són les escales, els acords i les fileres de tons. Fent servir eines matemàtiques de la branca de la combinatòria es resolen ...
    • Construcció de codis correctors a partir de configuracions i grafs 

      Basart i Muñoz, Josep M. (Universitat Politècnica de Barcelona. Centre de Càlcul, 1986-06)
      Article
      Accés obert
      Se trata de presentar algunas de las relaciones de carácter básicamente combinatorio que es posible encontrar entre dos tipos importantes de estructuras de incidencia, como son los grafos simétricos y las t-configuraciones, ...
    • Decomposition spaces in combinatorics 

      Gálvez Carrillo, Maria Immaculada; Kock, Joachim; Tonks, Andrew (2016-12)
      Report de recerca
      Accés obert
      A decomposition space (also called unital 2-Segal space) is a simplicial object satisfying an exactness condition weaker than the Segal condition: just as the Segal condition expresses (up to homotopy) composition, the new ...
    • Decomposition spaces, incidence algebras and Möbius inversion 

      Gálvez Carrillo, Maria Immaculada; Kock, Joachim; Tonks, Andrew (2014-04-11)
      Report de recerca
      Accés obert
    • Decomposition spaces, incidence algebras and Möbius inversion I: basic theory 

      Gálvez Carrillo, Maria Immaculada; Kock, Joachim; Tonks, Andrew (2015-12)
      Report de recerca
      Accés obert
      This is the first in a series of papers devoted to the theory of decomposition spaces, a general framework for incidence algebras and Möbius inversion, where algebraic identities are realised by taking homotopy cardinality ...
    • Decomposition spaces, incidence algebras and Möbius inversion II: completeness, length filtration, and finiteness 

      Gálvez Carrillo, Maria Immaculada; Kock, Joachim; Tonks, Andrew (2015-12)
      Report de recerca
      Accés obert
      This is part 2 of a trilogy of papers introducing and studying the notion of decomposition space as a general framework for incidence algebras and Möbius inversion, with coefficients in 8-groupoids. A decomposition space ...
    • Decomposition spaces, incidence algebras and Möbius inversion III: the decomposition space of Möbius intervals 

      Gálvez Carrillo, Maria Immaculada; Kock, Joachim; Tonks, Andrew (2015-12)
      Report de recerca
      Accés obert
      Decomposition spaces are simplicial 8-groupoids subject to a certain exactness condition, needed to induce a coalgebra structure on the space of arrows. Conservative ULF functors between decomposition spaces induce coalgebra ...
    • Enumeration and random generation of planar maps 

      Geffner Fuenmayor, Ivan Eduardo (Universitat Politècnica de Catalunya, 2014-07)
      Projecte Final de Màster Oficial
      Accés obert
      This works gives some results on outerplanar maps, which includes a codification of simple outerplanar maps with 3n bits, where n is the number of nodes. It also includes an algorithm to produce random generated maps with ...
    • Euler: Idees seminals en combinatòria 

      Brunat Blay, Josep Maria (2007-06-20)
      Audiovisual
      Accés obert
      De la quantitat ingent de treballs d'Euler, només una part molt minsa està dedicada a la combinatòria. Tanmateix, els pocs problemes combinatoris que Euler tractà han estat punt d'arrencada de desenvolupaments posteriors ...
    • Extended Abstracts EuroComb 2021 

      Nesetril, Jaroslav; Perarnau Llobet, Guillem; Rué Perna, Juan José; Serra Albó, Oriol (2021-09-01)
      Llibre
      Accés restringit per política de l'editorial
    • Genealogía de permutaciones simples de orden una potencia de dos 

      Acosta Humánez, Primitivo Belén (2006-02)
      Article
      Accés obert
      The aim of this paper is to show some properties of simple permutations with order a power of two and to give a combinatorial formula to determine its genealogy involving two new operations: the \textit{pasting} operation ...