Now showing items 1-20 of 33

    • The satisfiability problem in regular CNF-formulas 

      Manyà Serres, Felip; Béjar Torres, Ramón; Escalada Imaz, G. (Springer Verlag, 1998)
      In this paper we deal with the propositional satisfiability (SAT) problem for a kind of multiple-valued clausal forms known as regular CNF-formulas and extend some known results from classical logic to this kind ...
    • Extending the Reach of SAT with Many-Valued Logics 

      Béjar Torres, Ramón; Cabiscol i Teixidó, Alba; Fernàndez Camon, César; Manyà Serres, Felip; Gomes, Carla (Elsevier, 2001)
      We present Regular-SAT, an extension of Boolean Satisfiability based on a class of many-valued CNFform ulas. Regular-SAT shares many properties with Boolean SAT, which allows us to generalize some of the best known SAT ...
    • Capturing Structure with Satisfiability 

      Béjar Torres, Ramón; Cabiscol i Teixidó, Alba; Fernàndez Camon, César; Manyà Serres, Felip; Gomes, Carla (Springer Verlag, 2001)
      We present Regular-SAT, an extension of Boolean Satisfiability basedon a class of many-valuedCNF formulas. Regular-SAT shares many properties with Boolean SAT, which allows us to generalize some of the best known SAT ...
    • Towards an Automated Deduction System for First-Order Possibilistic Logic Programming with Fuzzy Constants 

      Alsinet, Teresa; Godo i Lacasa, Lluís (Wiley, 2002)
      In this article, we present a first-order logic programming language for fuzzy reasoning under possibilistic uncertainty and poorly known information. Formulas are represented by a pair (ϕ, α), in which ϕ is a first-order ...
    • Minimal and Redundant SAT Encodings for the All-Interval-Series Problem 

      Alsinet, Teresa; Béjar Torres, Ramón; Cabiscol i Teixidó, Alba; Fernàndez Camon, César; Manyà Serres, Felip (Springer Verlag, 2002)
      The SAT encodings defined so far for the all-interval-series (ais) problem are very hard for local search but rather easy for systematic algorithms. We define different SAT encodings for the ais problem and provide ...
    • Improved Branch and Bound Algorithms for Max-2-SAT and Weighted Max-2-SAT 

      Planes Cid, Jordi (Springer Verlag, 2003)
      We developed novel branch and bound algorithms for solving Max-SAT and weighted Max-SAT, which are variants of the algorithm of Borchers & Furman (BFA) [1]. We improved BFA by (i) defining a lower bound of better quality, ...
    • A Max-SAT Solver with Lazy Data Structures 

      Alsinet, Teresa; Manyà Serres, Felip; Planes Cid, Jordi (Springer Verlag, 2004)
      We present a new branch and bound algorithm for Max-SAT which incorporates original lazy data structures, a new variable selection heuristics and a lower bound of better quality. We provide experimental evidence that ...
    • An Argument-Based Framework to Model an Agent’s Beliefs in a Dynamic Environment 

      Capobianco, Marcela; Chesñevar, Carlos Iván; Simari, Guillermo Ricardo (Springer Verlag, 2005)
      One of the most difficult problems in multiagent systems involves representing knowledge and beliefs of agents in dynamic environments. New perceptions modify an agent’s current knowledge about the world, and consequently ...
    • Computing Dialectical Trees Efficiently in Possibilistic Defeasible Logic Programming 

      Chesñevar, Carlos Iván; Simari, Guillermo Ricardo; Godo i Lacasa, Lluís (Springer Verlag, 2005)
      Possibilistic Defeasible Logic Programming (P-DeLP) is a logic programming language which combines features from argumentation theory and logic programming, incorporating as well the treatment of possibilistic uncertainty ...
    • Modelling Power and Trust for Knowledge Distribution: An Argumentative Approach 

      Chesñevar, Carlos Iván; Brena, Ramón F.; Aguirre, José Luis (Springer Verlag, 2005)
      Knowledge and Information distribution, which is one of the main processes in Knowledge Management, is greatly affected by power explicit relations, as well as by implicit relations like trust. Making decisions about ...
    • Argument-Based Expansion Operators in Possibilistic Defeasible Logic Programming: Characterization and Logical Properties 

      Chesñevar, Carlos Iván; Simari, Guillermo Ricardo; Godo i Lacasa, Lluís; Alsinet, Teresa (Springer Verlag, 2005)
      Possibilistic Defeasible Logic Programming (P-DeLP) is a logic programming language which combines features from argumentation theory and logic programming, incorporating as well the treatment of possibilistic uncertainty ...
    • Statistical Regimes Across Constrainedness Regions 

      Gomes, Carla; Fernàndez Camon, César; Selman, Bart; Bessière, Christian (Springer Verlag, 2005)
      Much progress has been made in terms of boosting the effectiveness of backtrack style search methods. In addition, during the last decade, a much better understanding of problem hardness, typical case complexity, and ...
    • Knowledge Distribution in Large Organizations Using Defeasible Logic Programming 

      Chesñevar, Carlos Iván; Brena, Ramón F.; Aguirre, José Luis (Springer Verlag, 2005)
      Distributing pieces of knowledge in large, usually distributed organizations is a central problem in Knowledge and Organization Management. Policies for distributing knowledge and information are very often incomplete, ...
    • Argumentation and the Dynamics of Warranted Beliefs in Changing Environments 

      Capobianco, Marcela; Chesñevar, Carlos Iván; Simari, Guillermo Ricardo (Springer Verlag, 2005)
      One of the most difficult problems in Multi-Agent Systems (MAS) involves representing the knowledge and beliefs of an agent which performs its tasks in a dynamic environment. New perceptions modify this agent’s current ...
    • Sensor networks and distributed CSP: communication, computation and complexity 

      Béjar Torres, Ramón; Domshlak, Carmel; Fernàndez Camon, César; Gomes, Carla; Krishnamachari, Bhaskar; Selman, Bart; Valls Marsal, Magda (Elsevier, 2005)
      We introduce SensorDCSP, a naturally distributed benchmark based on a real-world application that arises in the context of networked distributed systems. In order to study the performance of Distributed CSP (DisCSP) ...
    • Communication and Computation in Distributed CSP Algorithms 

      Fernàndez Camon, César; Béjar Torres, Ramón; Krishnamachari, Bhaskar; Gomes, Carla (Springer Verlag, 2005)
      We introduce SensorDCSP, a naturally distributed benchmark based on a real-world application that arises in the context of networked distributed systems. In order to study the performance of Distributed CSP (DisCSP) ...
    • Improved Exact Solvers for Weighted Max-SAT 

      Alsinet, Teresa; Manyà Serres, Felip; Planes Cid, Jordi (Springer Verlag, 2005)
      We present two new branch and bound weighted Max-SAT solvers (Lazy and Lazy ) which incorporate original data structures and inference rules, and a lower bound of better quality
    • Solving Over-Constrained Problems with SAT Technology 

      Argelich Romà, Josep; Manyà Serres, Felip (Springer Verlag, 2005)
      We present a new generic problem solving approach for overconstrained problems based on Max-SAT. We first define a clausal form formalism that deals with blocks of clauses instead of individual clauses, and that allows ...
    • Exploiting Unit Propagation to Compute Lower Bounds in Branch and Bound Max-SAT Solvers 

      Li, Chu-Min; Manyà Serres, Felip; Planes Cid, Jordi (Springer Verlag, 2005)
      One of the main differences between complete SAT solvers and exact Max-SAT solvers is that the former make an intensive use of unit propagation at each node of the proof tree while the latter, in order to ensure optimality, ...
    • Exact Max-SAT solvers for over-constrained problems 

      Argelich Romà, Josep; Manyà Serres, Felip (Springer Verlag, 2006)
      We present a new generic problem solving approach for over-constrained problems based on Max-SAT. We first define a Boolean clausal form formalism, called soft CNF formulas, that deals with blocks of clauses instead of ...