Now showing items 1-7 of 7

  • Diseño e implementación de algoritmos de unificación y matching para términos comprimidos. 

    Ramos Garrido, Lander (Universitat Politècnica de Catalunya, 2011-06-30)
    Master thesis (pre-Bologna period)
    Open Access
    Las gramáticas incontextuales se pueden utilizar como herramienta para comprimir palabras o términos. Estas gramáticas pueden permitir en casos extremos comprimir hasta un factor exponencial. Sobre este tipo de compresiones ...
  • Excessively duplicating patterns represent non-regular languages 

    Creus López, Carles; Godoy Balil, Guillem; Ramos Garrido, Lander (2014-03-01)
    Article
    Restricted access - publisher's policy
    A constrained term pattern s:¿ represents the language of all instances of the term s satisfying the constraint ¿. For each variable in s, this constraint specifies the language of its allowed substitutions. Regularity of ...
  • Graph enumeration and random graphs 

    Ramos Garrido, Lander (Universitat Politècnica de Catalunya, 2017-03-27)
    Doctoral thesis
    Open Access
    In this thesis we use analytic combinatorics to deal with two related problems: graph enumeration and random graphs from constrained classes of graphs. We are interested in drawing a general picture of some graph families ...
  • Subgraph statistics in subcritical graph classes 

    Drmota, Michael; Ramos Garrido, Lander; Rué Perna, Juan José (2017-04-01)
    Article
    Open Access
    Let H be a fixed graph and math formula a subcritical graph class. In this paper we show that the number of occurrences of H (as a subgraph) in a graph in math formula of order n, chosen uniformly at random, follows a ...
  • The HOM problem is decidable 

    Godoy, Guillem; Giménez, Omer; Ramos Garrido, Lander; Álvarez Faura, M. del Carme (2009-06)
    External research report
    Open Access
    We close affirmatively a question which has been open for 35 years: decidability of the HOM problem. The HOM problem consists in deciding, given a tree homomorphism $H$ and a regular tree languagle $L$ represented by a ...
  • The HOM problem is EXPTIME-complete 

    Creus López, Carles; Gascon Caro, Adrian; Godoy Balil, Guillem; Ramos Garrido, Lander (2016)
    Article
    Open Access
    We define a new class of tree automata with constraints and prove decidability of the emptiness problem for this class in exponential time. As a consequence, we obtain several EXPTIME-completeness results for problems on ...
  • Too much duplicating patterns represent nonregular languages 

    Ramos Garrido, Lander (Universitat Politècnica de Catalunya, 2011)
    Master thesis
    Open Access
    A constrained term pattern s:phi represents the language of all instances of the term s satisfying the constraint phi. For each variable in s, this constraint specifies the language of its allowed substitutions. The ...