Now showing items 1-20 of 54

    • 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 highly parallel algorithm for computing the action of a matrix exponential on a vector based on a multilevel Monte Carlo method 

      Acebrón de Torres, Juan A.; Herrero Zaragoza, José Ramón; Monteiro, José (2020-01-01)
      Article
      Restricted access - publisher's policy
      A novel algorithm for computing the action of a matrix exponential over a vector is proposed. The algorithm is based on a multilevel Monte Carlo method, and the vector solution is computed probabilistically generating ...
    • A Massively Parallel Algorithm for the Approximate Calculation of Inverse p-th Roots of Large Sparse Matrices 

      Lass, Michael; Mohr, Stephan; Wiebeler, Hendrik; Kühne, Thomas D.; Plessl, Christian (Association for Computing Machinery (ACM), 2018-07)
      Conference lecture
      Open Access
      We present the submatrix method, a highly parallelizable method for the approximate calculation of inverse p-th roots of large sparse symmetric matrices which are required in different scientific applications. Following ...
    • A methodology for user-oriented scalability analysis 

      Royo Vallés, María Dolores; Valero García, Miguel; González Colás, Antonio María; Marí, Carme (Institute of Electrical and Electronics Engineers (IEEE), 1997)
      Conference report
      Open Access
      Scalability analysis provides information about the effectiveness of increasing the number of resources of a parallel system. Several methods have been proposed which use different approaches to provide this information. ...
    • A methodology for user-oriented scalability analysis. 

      Royo Vallés, María Dolores; Valero García, Miguel; González Colás, Antonio María; Mari Vila, Carme (IEEE, 1997-07-14)
      Conference report
      Open Access
      Scalability analysis provides information about the effectiveness of increasing the number of resources of a parallel system. Several methods have been proposed which use different approaches to provide this information. ...
    • A novel approach for hybrid performance modelling and prediction of large-scale computing systems 

      Pllana, Sabri; Benkner, Siegfried; Xhafa Xhafa, Fatos; Barolli, Leonard (2009)
      Article
      Restricted access - publisher's policy
      We present a novel approach for hybrid performance modeling and prediction of large-scale parallel and distributed computing systems, which combines mathematical modeling and discrete-event simulation. We use mathematical ...
    • A parallel algorithm for the computation of invariant tori in large-scale dissipative systems 

      Sánchez Umbría, Juan; Net Marcé, Marta (2013-06)
      Article
      Restricted access - publisher's policy
      A parallelizable algorithm to compute invariant tori of high-dimensional dissipative systems, obtained upon discretization of PDEs is presented. The size of the set of equations to be solved is only a small multiple of the ...
    • A Short note on non-symmetric semidefinite programming 

      Xhafa Xhafa, Fatos (1997-07)
      External research report
      Open Access
      We show that optimizing over non-symmetrical matrices is not polynomial solvable unless P=NP. This is in contrast to the symmetric case for which several polynomials time algorithms are known.
    • A study of the communication cost of the FFT on torus multicomputers 

      Díaz de Cerio Ripalda, Luis Manuel; Valero García, Miguel; González Colás, Antonio María (Institute of Electrical and Electronics Engineers (IEEE), 1995)
      Conference report
      Open Access
      The computation of a one-dimensional FFT on a c-dimensional torus multicomputer is analyzed. Different approaches are proposed which differ in the way they use the interconnection network. The first approach is based on ...
    • A systolic algorithm for the fast computation of the connected components of a graph 

      Núñez, Fernando J.; Valero Cortés, Mateo (Institute of Electrical and Electronics Engineers (IEEE), 1988)
      Conference report
      Open Access
      The authors consider the description of a systolic algorithm to solve the connected-component problem. It is executed in a ring topology with N processors, requiring O(Nlog N) time without regard to the graph's sparsity. ...
    • A Unified approach to concurrent and parallel algorithms on balanced data structures 

      Gabarró Vallès, Joaquim; Messeguer Peypoch, Xavier (1997-07)
      External research report
      Open Access
      Concurrent and parallel algorithms are different. However, in the case of dictionaries, both kinds of algorithms share many common points. We present a unified approach emphasizing these points. It is based on a careful ...
    • An adaptative fuzzy logic enhancer for rejection of narrowband interference in DS-Spread Spectrum 

      Pérez Neira, Ana Isabel; Antón Haro, Carles; Lagunas Hernandez, Miguel A. (1998)
      Conference report
      Open Access
      This work develops a novel adaptive fuzzy line enhancer that, based on a fuzzy basis function expansion, successfully solves the non-linear problem of narrowband interference estimation and rejection in direct sequence-spread ...
    • Benefits of SMT and of Parallel Transpose Algorithm for the Large-Scale GYSELA Application 

      Latu, Guillaume; Bigot, Julien; Bouzat, Nicolas; Gimenez, Judit; Grandgirard, Virginie (Association for Computing Machinery, 2016-06)
      Conference report
      Open Access
      This article describes how we manage to increase performance and to extend features of a large parallel application through the use of simultaneous multithreading (SMT) and by designing a robust parallel transpose algorithm. ...
    • Broadcast-enabled massive multicore architectures: a wireless RF approach 

      Abadal Cavallé, Sergi; Sheinman, Benny; Katz, Oded; Markish, Ofer; Elad, Danny; Fournier, Yvan; Roca, Damian; Hanzich, Mauricio; Houzeaux, Guillaume; Nemirovsky, Mario; Alarcón Cot, Eduardo José; Cabellos Aparicio, Alberto (2015-09)
      Article
      Open Access
      Broadcast traditionally has been regarded as a prohibitive communication transaction in multiprocessor environments. Nowadays, such a constraint largely drives the design of architectures and algorithms all-pervasive in ...
    • Cross-coupled doa trackers 

      Pérez Neira, Ana Isabel; Lagunas Hernandez, Miguel A.; Kirlin, R L (1997-10)
      Article
      Open Access
      A new robust, low complexity algorithm for multiuser tracking is proposed, modifying the two-stage parallel architecture of the estimate-maximize (EM) algorithm. The algorithm copes with spatially colored noise, large ...
    • CUDAlign 4.0: incremental speculative traceback for exact chromosome-wide alignment in GPU clusters 

      De Sandes, Edans; Miranda, Guillermo; Martorell Bofill, Xavier; Ayguadé Parra, Eduard; Teodoro, George; de Melo, Alba (2016-10-01)
      Article
      Open Access
      This paper proposes and evaluates CUDAlign 4.0, a parallel strategy to obtain the optimal alignment of huge DNA sequences in multi-GPU platforms, using the exact Smith-Waterman (SW) algorithm. In the first phase of CUDAlign ...
    • Distributed partitioning algorithm with application to video-surveillance 

      Paloma Garcia, Inés; Saiz, Carlos (Universitat Politècnica de Catalunya / Università degli Studi di Padova, 2014)
      Bachelor thesis
      Open Access
      How many times have we wanted to control an area and the video-surveillance system does not have the appropriate properties? Nowadays, the video-surveillance has become a responsibility by the necessity to patrol a ...
    • Dynamic energy-aware scheduling for parallel task-based application in cloud computing 

      Juarez Pérez, Fredy; Ejarque, Jorge; Badia Sala, Rosa Maria (Elsevier, 2018-01)
      Article
      Open Access
      Green Computing is a recent trend in computer science, which tries to reduce the energy consumption and carbon footprint produced by computers on distributed platforms such as clusters, grids, and clouds. Traditional ...
    • Efficient parallel construction of suffix trees for genomes larger than main memory 

      Comin, Matteo; Farreras Esclusa, Montserrat (ACM, 2013)
      Conference report
      Restricted access - publisher's policy
      The construction of suffix tree for very long sequences is essential for many applications, and it plays a central role in the bioinformatic domain. With the advent of modern sequencing technologies, biological sequence ...
    • Efficient parallel LAN/WAN algorithms for optimization: The mallba project 

      Alba, E.; Almeida, F.; Blesa Aguilera, Maria Josep; Cotta Porras, Carlos; Díaz, M.; Dorta, Isabel; Gabarró Vallès, Joaquim; León Hernández, Coromoto; Luque, G.; Petit Silvestre, Jordi; Rodríguez, C.; Rojas, A.; Xhafa Xhafa, Fatos (2006-06)
      Article
      Open Access
      The mallba project tackles the resolution of combinatorial optimization problems using generic algorithmic skeletons implemented in C++. A skeleton in the mallba library implements an optimization method in one of the three ...