Now showing items 21-40 of 55

  • FQ tardor 2018 

    Rué Perna, Juan José; Espona Dones, Margarida (Universitat Politècnica de Catalunya, 2018-01-08)
    Exam
    Restricted access to the UPC academic community
  • Graph classes with given 3-connected components: asymptotic counting, limit laws and critical phenomena 

    Giménez Llach, Omer; Noy Serrano, Marcos; Rué Perna, Juan José (Edicions de la Universitat de Lleida (UdL), 2008)
    Conference lecture
    Restricted access - publisher's policy
    Consider a family T of 3-connected graphs, and let G be the class of graphs whose 3-connected components are graphs in T . We present a general framework for analyzing such graphs classes based on singularity analysis of ...
  • Isolated cycles of critical random graphs 

    Noy Serrano, Marcos; Rasendrahasina, Vonjy; Ravelomanana, Vlady; Rué Perna, Juan José (Society for Industrial and Applied Mathematics (SIAM), 2017)
    Conference report
    Open Access
    Consider the Erdos-Renyi random graph G(n, M) built with n vertices and M edges uniformly randomly chosen from the set of n2 edges. Let L be a set of positive integers. For any number of edges M 6n/2 + O(n 2/3 ), we compute ...
  • Los números trascendentes 

    Fresán, Javier; Rué Perna, Juan José (Ediciones La Catarata, 2013-05)
    Book
    Restricted access - publisher's policy
    La expresión e¿ v163 es mucho más que la suma de sus partes e, ¿ y v163. Lejos de ser una elección casual, esta fórmula sirve a los autores de hilo conductor para adentrase en las áreas de la investigación más activa de ...
  • Many 2-level polytopes from matroids 

    Grande, Francesco; Rué Perna, Juan José (2015-10-26)
    Article
    Open Access
    The family of 2-level matroids, that is, matroids whose base polytope is 2-level, has been recently studied and characterized by means of combinatorial properties. 2-Level matroids generalize series-parallel graphs, which ...
  • Matemáticas y redes 

    Rué Perna, Juan José; Zumalacárregui, Ana (2014-01-01)
    Part of book or chapter of book
    Open Access
  • Maximal independent sets and maximal matchings in series-parallel and related graph classes 

    Drmota, Michael; Ramos, Lander; Requilé, Clément; Rué Perna, Juan José (Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2018)
    Conference lecture
    Open Access
    We provide combinatorial decompositions as well as asymptotic tight estimates for two maximal parameters: the number and average size of maximal independent sets and maximal matchings in seriesparallel graphs (and related ...
  • Memorial to Javier Cilleruelo: A Problem list 

    Candela, Pablo; Rué Perna, Juan José; Serra Albó, Oriol (2018-03-23)
    Article
    Open Access
    This is a list of problems in combinatorial number theory gathered on the occasion of the meeting The Music of Numbers to honor the memory of the late Javier Cilleruelo (1961-2016).
  • MQ primavera 2018 

    Espona Dones, Margarida; López Masip, Susana Clara; Rué Perna, Juan José (Universitat Politècnica de Catalunya, 2018-04-11)
    Exam
    Restricted access to the UPC academic community
  • MQ tardor 2018 

    Rué Perna, Juan José; Espona Dones, Margarida (Universitat Politècnica de Catalunya, 2018-11-07)
    Exam
    Restricted access to the UPC academic community
  • On a problem of Sárközy and Sós for multivariate linear forms 

    Rué Perna, Juan José; Spiegel, Christoph (2018-07-01)
    Article
    Restricted access - publisher's policy
    We prove that for pairwise co-prime numbers k1,...,kd = 2 there does not exist any infinite set of positive integers A such that the representation function rA(n) = #{(a1,...,ad) ¿ Ad : k1a1 + ... + kdad = n} becomes ...
  • On a question of Sárkozy and Sós for bilinear forms 

    Cilleruelo, Javier; Rué Perna, Juan José (2009-02-02)
    Article
    Restricted access - publisher's policy
    We prove that if 2 ≤ k1 ≤ k2, then there is no infinite sequence $\emph{A}$ of positive integers such that the representation function r(n)=#{(a, a'): n=$k{_1}a$ + $k{_2}a'$, a,a' ∊ $\emph{A}$} is constant for n large ...
  • On polynomial representation functions for multivariate linear forms 

    Rué Perna, Juan José (2013-11-01)
    Article
    Open Access
    Given an infinite sequence of positive integers A, we prove that for every nonnegative integer k the number of solutions of the equation n = a1 +· · ·+ak, a1, . . . , ak ¿ A, is not constant for n large enough. This result ...
  • On the error term of the logarithm of the lcm of quadratic sequences 

    Rué Perna, Juan José; Sarka, Paulius; Zumalacárregui, Ana (2013-01-09)
    Article
    Open Access
    We study the logarithm of the least common multiple of the sequence of integers given by 12 + 1, 2 2 + 1, . . . , n2 + 1. Using a result of Homma [4] on the distribution of roots of quadratic polynomials modulo primes we ...
  • On the fractional Parts of a^n/n 

    Cilleruelo, Javier; Luca, Florian; Kumchev, Angel; Rué Perna, Juan José; Shparlinski, Igor (2013-09-30)
    Article
    Open Access
    We give various results about the distribution of the sequence {a n/n}n=1 modulo 1, where a = 2 is a fixed integer. In particular, we find and infinite subsequence A such that {a n/n}n¿A is well distributed. Also we show ...
  • On the limiting distribution of the metric dimension for random forests 

    Rué Perna, Juan José; Mitsche, Dieter (2015-03-20)
    Article
    Open Access
    The metric dimension of a graph G is the minimum size of a subset S of vertices of G such that all other vertices are uniquely determined by their distances to the vertices in S. In this paper we investigate the metric ...
  • On the number of nonzero digits of some integer sequences 

    Cilleruelo, Javier; Luca, Florián; Rué Perna, Juan José; Zumalacárregui, Ana (2012-06-05)
    Article
    Open Access
    Let b = 2 be a fixed positive integer. We show for a wide variety of sequences {an}8n=1 that for most n the sum of the digits of an in base b is at least cb log n, where cb is a constant depending on b and on the sequence
  • On the optimality of the uniform random strategy 

    kush, Christopher; Rué Perna, Juan José; Spiegel, Christoph; Szabó, T. (2018-01-01)
    Article
    Restricted access - publisher's policy
    Biased Maker-Breaker games, introduced by Chvátal and Erdos, are central to the field of positional games and have deep connections to the theory of random structures. The main questions are to determine the smallest bias ...
  • Outerplanar obstructions for the vertex feedback set 

    Rué Perna, Juan José; Thilikos Touloupas, Dimitrios; Stavropoulos, Konstantinos (2012-07-02)
    Article
    Open Access
    For k = 1, let Fk be the class of graphs that contains k vertices meeting all its cycles. The minor-obstruction set for Fk is the set obs(Fk) containing all minor-minimal graphs that do not belong to Fk. We denote by Yk ...
  • Pentagonal chains and annuli as models for designing nanostructures from cages 

    Rosenfeld, Vladimir; Dubrynin, Andrey; Oliva, Josep Ma; Rué Perna, Juan José (2016-03-01)
    Article
    Open Access
    Carbon is the most versatile of chemical elements in combining with itself or other elements to form chains, rings, sheets, cages, and periodic 3D structures. One of the perspective trends for creating new molecules of ...