Now showing items 1-20 of 70

    • A Lattice Representation of Relations, Multivalued Dependencies and Armstrong Relations 

      Baixeries i Juvillà, Jaume; Balcázar Navarro, José Luis (2005)
      Conference report
      Restricted access - publisher's policy
      We present a lattice-base formalism to relate, in a novel way, different representation methods for relational data. Specifically, relations given extensionally by tuples, multivalued dependencies, and Armstrong relations ...
    • A lattice-based method for structural analysis 

      Casas Garriga, Gemma; Díaz López, Pablo; Balcázar Navarro, José Luis (2005-09)
      External research report
      Open Access
      In this paper we revisit the foundations of formal concept analysis for ordered contexts of [4]. From the theoretical point of view, the obtained lattice has proved to be a proper unifying framework for reasoning about ...
    • A New abstract combinatorial dimension for exact learning via queries 

      Balcázar Navarro, José Luis; Castro Rabal, Jorge; Guijarro Guillem, David (2000-02)
      External research report
      Open Access
      We introduce an abstract model of exact learning via queries that can be instantiated to all the query learning models currently in use, while being closer to them than previous unificatory attempts. We present a ...
    • A Note on genericity and bi-immunity 

      Balcázar Navarro, José Luis; Mayordomo, E (1994-11)
      External research report
      Open Access
      Generic sets have all properties (from among a suitably chosen class) that can be enforced by finite extension arguments. In particular, p-generic set are known to be P-bi-immune. We try to clarify the precise relationship ...
    • A Transformation scheme for double recursion 

      Balcázar Navarro, José Luis (1994-02)
      External research report
      Open Access
      A tail recursive program (with a single recursive call per case) is derived from a generic recursive program with two independent recursive calls, under no algebraic hypothesis whatsoever. The iterative version, fully ...
    • Adaptive logspace and depth-bounded reducibilities 

      Balcázar Navarro, José Luis (1991-04)
      External research report
      Open Access
      We discuss a number of results regarding an important subject: the study of the computational power of depth-bounded reducibilities, their use to classify the complexity of computational problems, and their characterizations ...
    • Algorithms for learning finite automata from queries: a unified view 

      Balcázar Navarro, José Luis; Díaz Cort, Josep; Gavaldà Mestre, Ricard; Watanabe, Osamu (1996-09)
      External research report
      Open Access
      In this survey we compare several known variants of the algorithm for learning deterministic finite automata via membership and equivalence queries. We believe that our presentation makes it easier to understand what ...
    • An optimal parallel algorithm for learning DFA 

      Balcázar Navarro, José Luis; Díaz Iriberri, José; Gavaldà Mestre, Ricard; Watanabe, O. (Universitat Politècnica de Catalunya. Departament de Llenguatges i Sistemes Informàtics, 1993-01-01)
      External research report
      Open Access
      In 1987, D. Angluin presented an algorithm that exactly learns regular languages represented by deterministic finite automata (dfa) from Membership and Equivalence queries. Furthermore, the algorithm is feasible in the ...
    • Border algorithms for computing Hasse diagrams of arbitrary lattices 

      Balcázar Navarro, José Luis; Tirnauca, Cristina (Springer, 2011)
      Conference report
      Restricted access - publisher's policy
      Lattices are mathematical structures with many applications in computer science; among these, we are interested in fields like data mining, machine learning, or knowledge discovery in databases. One well-established use ...
    • CALCULABILITAT (Examen 2n quadrim) 

      Balcázar Navarro, José Luis (Universitat Politècnica de Catalunya, 1999-06-10)
      Exam
      Restricted access to the UPC academic community
    • CALCULABILITAT (Examen 2n quadrim) 

      Balcázar Navarro, José Luis (Universitat Politècnica de Catalunya, 1998-06-10)
      Exam
      Restricted access to the UPC academic community
    • Canonical Horn representations and query learning 

      Arias Vicente, Marta; Balcázar Navarro, José Luis (2009-05)
      External research report
      Open Access
      We describe an alternative construction of an existing canonical representation for definite Horn theories, the emph{Guigues-Duquenne} basis (or GD basis), which minimizes a natural notion of implicational size. We extend ...
    • Characterization and Armstrong relations for Degenerated Multivalued Dependencies using Formal Concept Analysis 

      Baixeries i Juvillà, Jaume; Balcázar Navarro, José Luis (Springer, 2005)
      Conference report
      Restricted access - publisher's policy
      Functional dependencies, a notion originated in Relational Database Theory, are known to admit interesting characterizations in terms of Formal Concept Analysis. In database terms, two successive, natural extensions of ...
    • Characterizing the learnability of Kolmogorov easy circuit expressions 

      Balcázar Navarro, José Luis; Buhrman Canal, Harry (1996-01)
      External research report
      Open Access
      We show that Kolmogorov easy circuit expressions can be learned with membership queries in polynomial time if and only if every NE-predicate is E-solvable. Moreover we show that the previously known algorithm, that uses ...
    • Closed-set-based discovery of representative association rules 

      Tîrnauca, Cristina; Balcázar Navarro, José Luis; Gómez Pérez, Domingo (2020)
      Article
      Restricted access - publisher's policy
      The output of an association rule miner is often huge in practice. This is why several concise lossless representations have been proposed, such as the “essential” or “representative” rules. A previously known algorithm ...
    • Closed-set-based discovery of representative association rules revisited 

      Balcázar Navarro, José Luis; Tirnauca, Cristina (Hermann Éditions, 2011)
      Conference report
      Open Access
      The output of an association rule miner is often huge in practice. This is why several concise lossless representations have been proposed, such as the “essential” or “representative” rules. We revisit the algorithm given ...
    • Closures and partial implications in educational data mining 

      García Sáiz, Diego; Zorrilla Pantaleón, Marta Elena; Balcázar Navarro, José Luis (CEUR Workshop Proceedings, 2012)
      Conference report
      Open Access
      Educational Data Mining (EDM) is a growing field of use of data analysis techniques. Speci fically, we consider partial implications. The main problems are, fi rst, that a support threshold is absolutely necessary but ...
    • Co-occurrence patterns in diagnostic data 

      Piceno Cabrera, Marie Ely; Rodríguez Navas, Laura; Balcázar Navarro, José Luis (Wiley (John Wiley & Sons), 2020-04-12)
      Article
      Open Access
      We demonstrate how graph decomposition techniques can be employed for the visualization of hierarchical co-occurrence patterns between medical data items. Our research is based on Gaifman graphs (a mathematical concept ...
    • Coding complexity: the computational complexity of succinct descriptions 

      Balcázar Navarro, José Luis; Gavaldà Mestre, Ricard; Watanabe, Osamu (1996-09)
      External research report
      Open Access
      For a given set of strings, the problem of obtaining a succinct description becomes an important subject of research, related to several areas of theoretical computer science. In structural complexity theory, researchers ...
    • Competencias profesionales para el Grado en Ingeniería Informática 

      Sánchez Carracedo, Fermín; Sancho Samsó, María Ribera; Botella López, Pere; García Almiñana, Jordi; Aluja Banet, Tomàs; Navarro Guerrero, Juan José; Balcázar Navarro, José Luis (IEEE, Sociedad de Educación: Capítulos Español, Portugués y Colombiano, 2009)
      Part of book or chapter of book
      Open Access
      Degrees in the EHEA (European Higher Education Area) must be designed based on professional skills, so that when the students finish their studies they become competent professionals in the labour market. In this paper we ...