Now showing items 1-20 of 152

    • 2-D Tucker is PPA complete 

      Aisenberg, James; Bonet Carbonell, M. Luisa; Buss, Sam (2020-03)
      Article
      Open Access
      The 2-D Tucker search problem is shown to be PPA-hard under many-one reductions; therefore it is complete for PPA. The same holds for k-D Tucker for all k≥2. This corrects a claim in the literature that the Tucker search ...
    • A biased random key genetic algorithm for the weighted independent domination problem 

      Rodríguez Corominas, Guillem; Blum, Christian; Blesa Aguilera, Maria Josep (Association for Computing Machinery (ACM), 2019)
      Conference lecture
      Open Access
      This work deals with an NP-hard problem in graphs known as the weighted independent domination problem. We propose a biased random key genetic algorithm for solving this problem. The most important part of the proposed ...
    • A block algorithm for the algebraic path problem and its execution on a systolic array 

      Núñez, Fernando J.; Valero Cortés, Mateo (Institute of Electrical and Electronics Engineers (IEEE), 1989)
      Conference report
      Open Access
      The solution of the algebraic path problem (APP) for arbitrarily sized graphs by a fixed-size systolic array processor (SAP) is addressed. The APP is decomposed into two subproblems, and SAP is designed for each one. Both ...
    • A case for merging the ILP and DLP paradigms 

      Quintana Rodríguez, Francisca; Espasa Sans, Roger; Valero Cortés, Mateo (Institute of Electrical and Electronics Engineers (IEEE), 1998)
      Conference report
      Open Access
      The goal of this paper is to show that instruction level parallelism (ILP) and data-level parallelism (DLP) can be merged in a single architecture to execute vectorizable code at a performance level that can not be achieved ...
    • A combinatorial technique for separating counting complexity classes 

      Torán Romero, Jacobo (1988)
      External research report
      Open Access
      We introduce a new combinatorial technique to obtain relativized separations of certain complexity classes related to the idea of counting, like PP, G (exact counting), and ¿P (parity). To demonstrate its usefulness we ...
    • A fast OFDM-CDMA user demultiplexing architecture 

      Marti Puig, Pere; Sala Álvarez, José (Institute of Electrical and Electronics Engineers (IEEE), 2000)
      Conference report
      Open Access
      A fast algorithm based on a butterfly structure is presented that demultiplexes the symbols of a particular type of MC-MA (multi-carrier multiple-access) modulation previously proposed for indoor radio communications. A ...
    • A logic programming approach to parsing and production in fluid construction grammar 

      Sierra Santibáñez, Josefina (Springer, 2012)
      Part of book or chapter of book
      Restricted access - publisher's policy
      This paper presents a Logic Programming approach to parsing and production in Fluid Construction Grammar (FCG). It builds on previous work on the formalisation of FCG in terms of First Order Logic (FOL) concepts, more ...
    • A mathematical formulation of the loop pipelining problem 

      Cortadella, Jordi; Badia Sala, Rosa Maria; Sánchez Carracedo, Fermín (Universitat Politècnica de Catalunya (UPC), 1996)
      Conference report
      Open Access
      This paper presents a mathematical model for the loop pipelining problem that considers several parameters for optimization and supports any combination of resource and timing constraints. The unrolling degree of the loop ...
    • A parameterized halting problem, the linear time hierarchy, and the MRDP theorem 

      Chen, Yijia; Muller, Moritz Martin; Yokoyama, Keita (Association for Computing Machinery (ACM), 2018)
      Conference report
      Open Access
      The complexity of the parameterized halting problem for nondeterministic Turing machines p-Halt is known to be related to the question of whether there are logics capturing various complexity classes [10]. Among others, ...
    • A performance characterization of high definition digital video decoding using H.264/AVC 

      Álvarez Mesa, Mauricio; Salamí San Juan, Esther; Ramírez Bellido, Alejandro; Valero Cortés, Mateo (Institute of Electrical and Electronics Engineers (IEEE), 2005)
      Conference report
      Open Access
      H.264/AVC is a new international video coding standard that provides higher coding efficiency with respect to previous standards at the expense of a higher computational complexity. The complexity is even higher when ...
    • A positive relativization of polynomial time vs. polylog space 

      Gavaldà Mestre, Ricard (1991-05)
      External research report
      Open Access
      Can every set in P be solved in polylogarithmic space? We show that this question is equivalent to asking whether the classes PSPACE and EXPTIME are always equal under relativization. We use an oracle access mechanism that ...
    • A reduced-complexity and asymptotically efficient time-delay estimator 

      Seco Granados, Gonzalo; Swindlehurst, A L; Fernández Rubio, Juan Antonio; Astély, D (ICASSP, 2000)
      Conference report
      Open Access
      This paper considers the problem of estimating the time delays of multiple replicas of a known signal received by an array of antennas. Under the assumptions that the noise and co-channel interference (CCI) are spatially ...
    • A study of the human-system interface complexity sources in wastewater treatment plants 

      Ponsa Asensio, Pere; Pérez, Àlex; Gámiz Caro, Javier Francisco; Manresa-Yee, Cristina; Vilanova, Ramon (Universidad de Zaragoza, 2012)
      Conference report
      Restricted access - publisher's policy
      In human-automation interaction it is necessary to define methods and tools to assess the human-system interface complexity. In a first assessment, the use of an evaluation questionnaire aiming at detecting complexity ...
    • Acceleration of Born series by change of variables 

      López Menchón, Héctor; Rius Casals, Juan Manuel; Heldring, Alexander; Úbeda Farré, Eduard (2021-09)
      Article
      Open Access
      In this work, we propose a method to enhance the convergence of the Born series. The Born series is widely used in scattering theory, but its convergence is only guaranteed under certain restrictive conditions which limit ...
    • 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 ...
    • Adaptive logspace reducibility and parallel time 

      Álvarez Faura, M. del Carme; Balcázar Navarro, José Luis; Jenner, Birgit (1991-11)
      External research report
      Open Access
      We discuss two notions of functional oracle for logarithmic space-bounded machines, which differ in whether there is only one oracle tape for both the query and the answer or a separate tape for the answer, which can still ...
    • Algorismes parametritzats per al problema de recobriment d'imatges 

      Winand, Tomàs (Universitat Politècnica de Catalunya, 2007-01-14)
      Master thesis (pre-Bologna period)
      Open Access
    • Aligning modeled and observed behavior: A compromise between computation complexity and quality 

      Dongen, Boudewijn F. van; Carmona Vargas, Josep; Chatain, Thomas; Taymouri, Farbod (Springer, 2017)
      Conference report
      Open Access
      Certifying that a process model is aligned with the real process executions is perhaps the most desired feature a process model may have: aligned process models are crucial for organizations, since strategic decisions can ...
    • Almost every set in exponential time is P-Bi-Immune 

      Mayordomo, Elvira (1991-11-06)
      External research report
      Open Access
      A set A is P-bi-immune if neither A nor its complement has an infinite subset in P. We investigate here the abundance of P-bi-immune languages in linear-exponential time (E). We prove that the class of P-bi-immune sets ...
    • An efficient solver for Cache Miss Equations 

      Bermudo, Nerina; Vera Rivera, Francisco Javier; González Colás, Antonio María; Llosa Espuny, José Francisco (Institute of Electrical and Electronics Engineers (IEEE), 2000)
      Conference report
      Open Access
      Cache Miss Equations (CME) (S. Ghosh et al., 1997) is a method that accurately describes the cache behavior by means of polyhedra. Even though the computation cost of generating CME is a linear function of the number of ...