Now showing items 1-20 of 77

    • A lower bound for learning distributions generated by probabilistic automata 

      Balle Pigem, Borja de; Castro Rabal, Jorge; Gavaldà Mestre, Ricard (Springer, 2010)
      Conference report
      Open Access
      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. ...
    • A new spectral method for latent variable models 

      Ruffini, Matteo; Casanellas Rius, Marta; Gavaldà Mestre, Ricard (2018-05-22)
      Article
      Open Access
      We present an algorithm for the unsupervised learning of latent variable models based on the method of moments. We give efficient estimates of the moments for two models that are well known, e.g., in text mining, the ...
    • 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)
      Conference report
      Restricted access - publisher's policy
      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)
      Conference report
      Open Access
      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)
      External research report
      Open Access
      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)
      External 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 ...
    • 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)
      Conference report
      Restricted access - publisher's policy
      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)
      External research report
      Open Access
      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
      Restricted access - publisher's policy
      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 ...
    • Adarules: Learning rules for real-time road-traffic prediction 

      Mena Yedra, Rafael; Gavaldà Mestre, Ricard; Casas Vilaró, Jordi (Elsevier, 2017-12-17)
      Conference report
      Open Access
      Traffic management is being more important than ever, especially in overcrowded big cities with over-pollution problems and with new unprecedented mobility changes. In this scenario, road-traffic prediction plays a key ...
    • 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 efficient closed frequent itemset miner for the MOA stream mining system 

      Quadrana, Massimo; Bifet Figuerol, Albert Carles; Gavaldà Mestre, Ricard (2015-01-07)
      Article
      Open Access
      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)
      External research report
      Open Access
      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)
      External research report
      Open Access
      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)
      External research report
      Open Access
      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)
      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 ...
    • Applying trust metrics based on user interactions to recommendation in social networks 

      Lumbreras, Alberto; Gavaldà Mestre, Ricard (2012)
      External research report
      Open Access
      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 ...
    • Assessing spatiotemporal correlations from data for short-term traffic prediction using multi-task learning 

      Mena Yedra, Rafael; Casas Vilaró, Jordi; Gavaldà Mestre, Ricard (Elsevier, 2018-12-04)
      Article
      Open Access
      Traffic flow prediction is a fundamental problem for efficient transportation control and management. However, most current data-driven traffic prediction work found in the literature have focused on predicting traffic ...
    • BASES DE DADES (Examen 2n quadrim) 

      Gavaldà Mestre, Ricard (Universitat Politècnica de Catalunya, 2007-05-23)
      Exam
      Restricted access to the UPC academic community
    • Bases de Dades (Examen 2n quadrimestre) 

      Gavaldà Mestre, Ricard (Universitat Politècnica de Catalunya, 2007-06-29)
      Exam
      Restricted access to the UPC academic community