Ara es mostren els items 1-20 de 60

  • A lower bound for learning distributions generated by probabilistic automata 

    Balle Pigem, Borja de; Castro Rabal, Jorge; Gavaldà Mestre, Ricard (Springer, 2010)
    Text en actes de congrés
    Accés obert
    Known algorithms for learning PDFA can only be shown to run in time polynomial in the so-called distinguishability μ of the target machine, besides the number of states and the usual accuracy and confidence parameters. ...
  • Adaptive distributed mechanism againts flooding network attacks based on machine learning 

    Berral García, Josep Lluís; Poggi Mastrokalo, Nicolas; Alonso López, Javier; Gavaldà Mestre, Ricard; Torres Viñals, Jordi; Parashar, Manish (ACM Press, NY, 2008)
    Text en actes de congrés
    Accés restringit per política de l'editorial
    Adaptive techniques based on machine learning and data mining are gaining relevance in self-management and self- defense for networks and distributed systems. In this paper, we focus on early detection and stopping of ...
  • Adaptive on-line software aging prediction based on machine learning 

    Alonso López, Javier; Torres Viñals, Jordi; Berral García, Josep Lluís; Gavaldà Mestre, Ricard (IEEE Computer Society Publications, 2010)
    Text en actes de congrés
    Accés obert
    The growing complexity of software systems is resulting in an increasing number of software faults. According to the literature, software faults are becoming one of the main sources of unplanned system outages, and have ...
  • Adaptive parameter-free learning from evolving data streams 

    Bifet Figuerol, Albert Carles; Gavaldà Mestre, Ricard (2009-03)
    Report de recerca
    Accés obert
    We propose and illustrate a method for developing algorithms that can adaptively learn from data streams that change over time. As an example, we take Hoeffding Tree, an incremental decision tree inducer for data streams, ...
  • Adaptive sampling methods for scaling up knowledge discovery algorithms 

    Domingo Soriano, Carlos; Gavaldà Mestre, Ricard; Watanabe, Osamu (2001-07)
    Report de recerca
    Accés obert
    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 ...
  • Adaptive scheduling on power-aware managed data-centers using machine learning 

    Berral García, Josep Lluís; Gavaldà Mestre, Ricard; Torres Viñals, Jordi (IEEE Computer Society Publications, 2011)
    Text en actes de congrés
    Accés restringit per política de l'editorial
    Energy-related costs have become one of the major economic factors in IT data-centers, and companies and the research community are currently working on new efficient power-aware resource management strategies, also known ...
  • Adaptive scheduling on power-aware managed data-centers using machine learning 

    Berral García, Josep Lluís; Gavaldà Mestre, Ricard; Torres Viñals, Jordi (2011)
    Report de recerca
    Accés obert
    Energy-related costs have become one of the major economic factors in IT data-centers, and companies and the research community are currently working on new efficient power-aware resource management strategies, also known ...
  • Adaptively learning probabilistic deterministic automata from data streams 

    Balle Pigem, Borja de; Castro Rabal, Jorge; Gavaldà Mestre, Ricard (2014-07)
    Article
    Accés restringit per política de l'editorial
    Markovian models with hidden state are widely-used formalisms for modeling sequential phenomena. Learnability of these models has been well studied when the sample is given in batch mode, and algorithms with PAC-like ...
  • Algorithms for learning finite automata from queries: a unified view 

    Balcázar Navarro, José Luis; Díaz Cort, Josep; Gavaldà Mestre, Ricard; Watanabe, Osamu (1996-09)
    Report de recerca
    Accés obert
    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 efficient closed frequent itemset miner for the MOA stream mining system 

    Quadrana, Massimo; Bifet Figuerol, Albert Carles; Gavaldà Mestre, Ricard (2015-01-07)
    Article
    Accés obert
    Mining itemsets is a central task in data mining, both in the batch and the streaming paradigms. While robust, efficient, and well-tested implementations exist for batch mining, hardly any publicly available equivalent ...
  • An efficient closed frequent itemset miner for the MOA stream mining system 

    Quadrana, Massimo; Bifet Figuerol, Albert Carles; Gavaldà Mestre, Ricard (2013)
    Report de recerca
    Accés obert
    Mining itemsets is a central task in data mining, both in the batch and the streaming paradigms. While robust, efficient, and well-tested implementations exist for batch mining, hardly any publicly available equivalent ...
  • An integer linear programming representation for data-center power-aware management 

    Berral García, Josep Lluís; Gavaldà Mestre, Ricard; Torres Viñals, Jordi (2010-11-12)
    Report de recerca
    Accés obert
    This work exposes how to represent a grid data-center based scheduling problem, taking the advantages of the virtualization and consolidation techniques, as a linear integer programming problem including all three mentioned ...
  • An optimal anytime estimation algorithm 

    Gavaldà Mestre, Ricard (2004-12)
    Report de recerca
    Accés obert
    In many applications a key step is estimating some unknown quantity ~$mu$ from a sequence of trials, each having expected value~$mu$. Optimal algorithms are known when the task is to estimate $mu$ within a multiplicative ...
  • 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)
    Report de recerca
    Accés obert
    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 ...
  • Applying trust metrics based on user interactions to recommendation in social networks 

    Lumbreras, Alberto; Gavaldà Mestre, Ricard (2012)
    Report de recerca
    Accés obert
    Recommender systems have been strongly researched within the last decade. With the arising and popularization of digital social networks a new field has been opened for social recommendations. Considering the network ...
  • Bootstrapping and learning PDFA in data streams 

    Balle Pigem, Borja de; Castro Rabal, Jorge; Gavaldà Mestre, Ricard (2012)
    Text en actes de congrés
    Accés obert
    Markovian models with hidden state are widely-used formalisms for modeling sequential phenomena. Learnability of these models has been well studied when the sample is given in batch mode, and algorithms with PAC-like ...
  • Bounding the expected length of longest common subsequences and forests 

    Scheihing, R.; Navarro, G.; Gavaldà Mestre, Ricard; Baeza-Yates, R. (1998-09-01)
    Report de recerca
    Accés obert
    We present improvements to two techniques to find lower and upper bounds for the expected length of longest common subsequences and forests of two random sequences of the same length, over a fixed size, uniformly ...
  • Bounding the expected length of longest common subsequences and forests 

    Baeza-Yates, Ricardo A; Gavaldà Mestre, Ricard; Navarro, Gonzalo (1996-05)
    Report de recerca
    Accés obert
    Subsumed by LSI-98-50-R
  • Building green cloud services at low cost 

    Berral García, Josep Lluís; Goiri, Iñigo; Nguyen, Thu D.; Gavaldà Mestre, Ricard; Torres Viñals, Jordi; Bianchini, Ricardo (Institute of Electrical and Electronics Engineers (IEEE), 2014)
    Comunicació de congrés
    Accés obert
    Interest in powering datacenters at least partially using on-site renewable sources, e.g. solar or wind, has been growing. In fact, researchers have studied distributed services comprising networks of such “green” datacenters, ...
  • Characterization of the CPAP-treated patient population in Catalonia 

    Turino, Cecilia; Bertrán, Sandra; Gavaldà Mestre, Ricard; Teixidó, Ivan; Woehrle, Holger; Rué, Montserrat; Solsona, Francesc; Escarrabill, Joan; Colls, Cristina; García Altés, Anna; Batlle, Jordi de; Sánchez de la Torre, Manuel; Barbé, Ferran (2017-09-21)
    Article
    Accés obert
    There are different phenotypes of obstructive sleep apnoea (OSA), many of which have not been characterised. Identification of these different phenotypes is important in defining prognosis and guiding the therapeutic ...