Exploració per tema "Combinatorics"
Ara es mostren els items 1-20 de 36
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A fast and efficient algorithm to identify clusters in networks
(2008-08-02)
Article
Accés obertA 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
(Universitat Politècnica de Catalunya, 2019-01)
Projecte Final de Màster Oficial
Accés obertMatroids 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
(De Gruyter, 2019-03-06)
Article
Accés obertA 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
(1997-11)
Article
Accés obertLet $\Gamma$ 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
(2007-10-02)
Article
Accés obertWe 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
(2009-01-20)
Comunicació de congrés
Accés obertThis 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
(2009-05)
Article
Accés obertA 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
(Springer, 2021)
Capítol de llibre
Accés obertThis 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
(2009-06)
Report de recerca
Accés obertGiven 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
(Universitat Politècnica de Catalunya, 2021-05)
Treball Final de Grau
Accés obertEn 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
(Universitat Politècnica de Barcelona. Centre de Càlcul, 1986-06)
Article
Accés obertSe 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
(2016-12)
Report de recerca
Accés obertA 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
(2014-04-11)
Report de recerca
Accés obert -
Decomposition spaces, incidence algebras and Möbius inversion I: basic theory
(2015-12)
Report de recerca
Accés obertThis 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
(2015-12)
Report de recerca
Accés obertThis 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
(2015-12)
Report de recerca
Accés obertDecomposition 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
(Universitat Politècnica de Catalunya, 2014-07)
Projecte Final de Màster Oficial
Accés obertThis 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
(2007-06-20)
Audiovisual
Accés obertDe 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
(2021-09-01)
Llibre
Accés restringit per política de l'editorial -
Genealogía de permutaciones simples de orden una potencia de dos
(2006-02)
Article
Accés obertThe 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 ...