Now showing items 1-12 of 12

    • A framework for polynomial time query learnability 

      Watanabe, Osamu (1990)
      Research report
      Open Access
    • A note on the query complexity of learning DFA 

      Balcázar Navarro, José Luis; Díaz Cort, Josep; Gavaldà Mestre, Ricard; Watanabe, Osamu (1992)
      Research report
      Open Access
      It is known that the class of deterministic finite automata is polynomial time learnable by using membership and equivalence queries. We investigate -- the query complexity -- the number of membership and equivalence queries ...
    • Adaptive sampling methods for scaling up knowledge discovery algorithms 

      Domingo Soriano, Carlos; Gavaldà Mestre, Ricard; Watanabe, Osamu (2001-07)
      Research report
      Open Access
      One of the biggest research challenges in KDD and Data Mining is to develop methods that scale up well to large amounts of data. A possible approach for achieving scalability is to take a random sample and do data mining ...
    • Algorithms for learning finite automata from queries: a unified view 

      Balcázar Navarro, José Luis; Díaz Cort, Josep; Gavaldà Mestre, Ricard; Watanabe, Osamu (1996-09)
      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 ...
    • Coding complexity: the computational complexity of succinct descriptions 

      Balcázar Navarro, José Luis; Gavaldà Mestre, Ricard; Watanabe, Osamu (1996-09)
      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 ...
    • Computational complexity of small descriptions 

      Gavaldà Mestre, Ricard; Watanabe, Osamu (1990-11-19)
      Research report
      Open Access
      For a set L that is polynomial time reducible (in short, = sub T super P-reducible) to some sparse set, we investigate the computational complexity of such sparse sets relative to L. We construct sets A and B such that ...
    • Generalized Kolmogorov complexity in relativized separations 

      Gavaldà Mestre, Ricard; Torenvliet, Leen; Watanabe, Osamu; Balcázar Navarro, José Luis (1990-04)
      Research report
      Open Access
      We describe several developments of a technique, due to Hartmanis, that uses Kolmogorov complexity to prove the existence of relativizations separating complexity classes. The main advantage of these proofs is that they ...
    • On sets bounded truth-table reducible to P-selective sets 

      Thierauf, Thomas; Toda, Seinosuke; Watanabe, Osamu (Universitat Politècnica de Catalunya. Departament de Llenguatges i Sistemes Informàtics, 1993)
      Conference report
      Open Access
      We show that if every NP set is ≤ P btt -reducible to some P-selective set, then NP is contained in DTIME(2nO(1/logn√)). The result is extended for some unbounded reducibilities such as ≤ P polylog-tt -reducibility.
    • On-line sampling methods for discovering association rules 

      Domingo Soriano, Carlos; Gavaldà Mestre, Ricard; Watanabe, Osamu (1999-02)
      Research report
      Open Access
      Association rule discovery is one of the prototypical problems in data mining. In this problem, the input database is assumed to be very large and most of the algorithms are designed to minimize the number of scans of ...
    • Sequential sampling algorithms: unified analysis and lower bounds 

      Gavaldà Mestre, Ricard; Watanabe, Osamu (2001-11)
      Research report
      Open Access
      Sequential sampling algorithms have recently attracted interest as a way to design scalable algorithms for Data mining and KDD processes. In this paper, we identify an elementary sequential sampling task (estimation from ...
    • Simulation of complicated queries by membership queries 

      Díaz Cort, Josep; Watanabe, Osamu (1990)
      Research report
      Open Access
      In this paper, we consider the following type of learning: a teacher has some set, which is called a (target) concept, in his mind, and a learner tries to obtain the representation of the concept by asking queries on it ...
    • Structural analysis of polynomial time query learnability 

      Watanabe, Osamu; Gavaldà Mestre, Ricard (1992-03-12)
      Research report
      Open Access
      For some representation classes, we relate its polynomial time query learnability to the complexity of representation finding problems of P/poly oracles. For example, for CIR, a representation class by logical circuits, ...