Now showing items 1-20 of 26

  • 4-Holes in point sets 

    Aichholzer, Oswin; Fabila Monroy, Ruy; Gonzalez Aguilar, Hernan; Hackl, Thomas; Heredia, Marco A.; Huemer, Clemens; Urrutia Galicia, Jorge; Vogtenhuber, Birgit (2014-08-01)
    Article
    Open Access
    We consider a variant of a question of Erdos on the number of empty k-gons (k-holes) in a set of n points in the plane, where we allow the k-gons to be non-convex. We show bounds and structural results on maximizing and ...
  • A note on flips in diagonal rectangulations 

    Cardinal, Jean; Sacristán Adinolfi, Vera; Silveira, Rodrigo Ignacio (Chapman & Hall/CRC, 2018-11-09)
    Article
    Open Access
    Rectangulations are partitions of a square into axis-aligned rectangles. A number of results provide bijections between combinatorial equivalence classes of rectangulations and families of pattern-avoiding permutations. ...
  • Asymptotics of sequences 

    Bender, Edward; Rué Perna, Juan José (2017-12-01)
    Part of book or chapter of book
    Restricted access - publisher's policy
  • Bounds on the size of super edge-magic graphs depending on the girth 

    Ichishima, Rikio; Muntaner Batle, Francesc Antoni; Rius Font, Miquel (2009-12-13)
    External research report
    Open Access
    Let G = (V,E) be a graph of order p and size q. It is known that if G is super edge-magic graph then q 2p−3. Furthermore, if G is super edge-magic and q = 2p−3, then the girth of G is 3. It is also known that if the ...
  • Comunitats en xarxes complexes: detecció i centralitat 

    Quintana Mathé, Alexi (Universitat Politècnica de Catalunya, 2017-07)
    Bachelor thesis
    Open Access
    En aquest treball estudiem l'estructura de comunitats en xarxes complexes. S'anomenen xarxes complexes als grafs construïts a partir de dades empíriques complint una sèrie de propietats, i s'entén per comunitat en un xarxa ...
  • (Di)graph products, labelings and related results 

    López Masip, Susana Clara (2017-07)
    Article
    Open Access
    Gallian's survey shows that there is a big variety of labelings of graphs. By means of (di)graphs products we can establish strong relations among some of them. Moreover, due to the freedom of one of the factors, we can ...
  • Dirichlet-to-Robin maps on finite networks 

    Arauz Lombardía, Cristina; Carmona Mejías, Ángeles; Encinas Bachiller, Andrés Marcos (2015-04-01)
    Article
    Open Access
    Our aim is to characterize those matrices that are the response matrix of a semi positive definite Schrodinger operator on a circular planar network. Our findings generalize the known results and allow us to consider both ...
  • El arte de contar: combinatoria y enumeración 

    Rué Perna, Juan José (RBA Libros, 2011-06-01)
    Book
    Restricted access - publisher's policy
    Muchas de las preguntas más importantes de las matemáticas modernas requieren dominar un arte muy especial: el de contar. La rama de las matemáticas que ha hecho del enumerar un arte se llama combinatoria, y de la mano de ...
  • Empowering teachers' self assessment of their own practice on student's oral skills: EVALOE decision support system 

    Grácia, M.; Casanovas Garcia, Josep; Sancho Samsó, María Ribera; Casanovas Muñoz, Jordi; Cuatrecasas Capdevila, Marta (Scitepress, 2018)
    Conference report
    Restricted access - publisher's policy
    School is an essential context that contributes to children's communicative competence. Decision Support Systems (DSS) are tools that can help teachers to assess their own practice and to make decisions to improve it (Gregg, ...
  • Empty monochromatic simplices 

    Aichholzer, Oswin; Fabila Monroy, Ruy; Hackl, Thomas; Huemer, Clemens; Urrutia Galicia, Jorge (2014-03-01)
    Article
    Open Access
    Let S be a k-colored (finite) set of n points in , da parts per thousand yen3, in general position, that is, no (d+1) points of S lie in a common (d-1)-dimensional hyperplane. We count the number of empty monochromatic ...
  • Enumerating super edge-magic labelings for some types of path-like trees 

    López Masip, Susana Clara; Muntaner Batle, Francesc Antoni; Rius Font, Miquel (2010-06-02)
    Article
    Open Access
    The main goal of this paper is to use a variation of the Kronecker product of matrices in order to obtain lower bounds for the number of non isomorphic super edge-magic labelings of some types of path-like trees. As a ...
  • Extraction of threshold functions from formulas in propositional logic 

    Milesi Vidal, Eric (Universitat Politècnica de Catalunya, 2017-01)
    Bachelor thesis
    Restricted access - author's decision
    Given a formula in propositional logic F in some presentation (BDD, ROBDD, truth table), our aim is to find a threshold function T that is a logical consequence of F and that is as strong as possible according to certain ...
  • Logaritme discret i aplicacions a la criptografia 

    Ferrer Fernàndez, Sergi (Universitat Politècnica de Catalunya, 2015-07)
    Bachelor thesis
    Open Access
    El logaritme discret és un isomorfisme entre el grup de les classes de congruència mòdul n i el grup G. Aquesta aplicació és molt útil per a crear protocols criptogràfics de clau pública. La seguretat d'aquests sistemes ...
  • Online coloring problem with a randomized adversary and infinite advice 

    Burjons Pujol, Elisabet (Universitat Politècnica de Catalunya, 2015-07)
    Master thesis
    Open Access
    Online problems are those in which the instance is not given as a whole but by parts named requests. They arrise naturaly in computer science. Several examples are given such as ski rental problem, the server problem and ...
  • El problema grau-nombre de vèrtexs en digrafs de doble pas amb diàmetre unilateral 

    Romero Nevado, Cristina (Universitat Politècnica de Catalunya, 2013-02-26)
    Bachelor thesis
    Open Access
    Generally speaking, the aim of this work is to study the (Δ,N) problem (or the degree-number of vertices problem) for double-step digraphs. A digraph is a network consisting of vertices and directed edges (called ...
  • Quantification of network structural dissimilarities 

    Schieber, Tiabo A.; Carpi, Laura; Díaz Guilera, Albert; Pardalos, Panos M.; Masoller Alonso, Cristina; Ravetti, Martin G. (2017-01-09)
    Article
    Open Access
    Identifying and quantifying dissimilarities among graphs is a fundamental and challenging problem of practical importance in many fields of science. Current methods of network comparison are limited to extract only partial ...
  • Rainbow spanning subgraphs in bounded edge–colourings of graphs with large minimum degree 

    Cano Vila, María del Pilar; Perarnau Llobet, Guillem; Serra Albó, Oriol (2017-08-01)
    Article
    Restricted access - publisher's policy
    We study the existence of rainbow perfect matching and rainbow Hamiltonian cycles in edge–colored graphs where every color appears a bounded number of times. We derive asymptotically tight bounds on the minimum degree of ...
  • Secret sharing schemes: Optimizing the information ratio 

    Hernández Ansuátegui, Félix (Universitat Politècnica de Catalunya, 2017-07)
    Bachelor thesis
    Open Access
    Secret sharing refers to methods used to distribute a secret value among a set of participants. This work deals with the optimization of two parameters regarding the efficiency of a secret sharing scheme: the information ...
  • Semantic clustering based on ontologies: an application to the study of visitors in a natural reserve 

    Batet, Montserrat; Valls, Aïda; Gibert, Karina (2011)
    Conference report
    Open Access
    The development of large ontologies for general and specific domains provides new tools to improve the quality of data mining techniques such as clustering. In this paper we explain how to improve clustering results by ...
  • Specification and description language for discrete simulation 

    Fonseca Casas, Pau (IGI Global, 2013-07)
    Part of book or chapter of book
    Restricted access - publisher's policy
    Designing a new simulation model usually involves the participation of personnel with different knowledge of the system and with diverse formations. These personnel often use different languages, making more difficult ...