Now showing items 1-16 of 16

  • 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. ...
  • Bounded expansion in models of webgraphs 

    Gago Álvarez, Silvia; Schlatter, Dirk (2007-10-02)
    Article
    Open Access
    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 ...
  • 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 ...
  • 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, ...
  • 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 ...
  • 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
    Open Access
    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 ...
  • Self-similar non-clustered planar graphs as models for complex networks 

    Comellas Padró, Francesc de Paula; Zhang, Zhongzhi; Chen, Lichao (2008-10-10)
    Article
    Open Access
    In this paper we introduce a family of planar, modular and self-similar graphs which have small-world and scale-free properties. The main parameters of this family are comparable to those of networks associated with complex ...
  • 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 ...
  • Structure and enumeration of K4-minor-free links and link diagrams 

    Rué Perna, Juan José; Thilikos Touloupas, Dimitrios; Velona, Vasiliki (2018-07-01)
    Article
    Restricted access - publisher's policy
    We study the class L of link-types that admit a K4-minor-free diagram, i.e., they can be projected on the plane so that the resulting graph does not contain any subdivision of K4. We prove that L is the closure of a subclass ...
  • Systematic strategies for 3-dimensional modular robots 

    De Parada Muñoz, Irene María (Universitat Politècnica de Catalunya, 2015-07)
    Master thesis
    Open Access
    Modular robots have been studied an classified from different perspectives, generally focusing on the mechatronics. But the geometric attributes and constraints are the ones that determine the self-reconfiguration strategies. ...
  • The Kernel Matrix Diffie-Hellman assumption 

    Morillo Bosch, M. Paz; Ràfols Salvador, Carla; Villar Santos, Jorge Luis (Springer, 2016)
    Conference lecture
    Open Access
    We put forward a new family of computational assumptions, the Kernel Matrix Diffie-Hellman Assumption. Given some matrix A sampled from some distribution D, the kernel assumption says that it is hard to find “in the exponent” ...
  • The referee assignment problem 

    Vallespi Soro, Farners (Universitat Politècnica de Catalunya, 2019-07)
    Bachelor thesis
    Open Access
    In collaboration between a UPC spinoff, Barcelogic, and the Dutch Football Federation (KNVB), we define, study, implement and evaluate different approaches for solving the so-called Referee Assignment Problem(RAP). In this ...