Now showing items 1-20 of 35

    • Parallel Sparse Modified Gram-Schmidt QR Decomposition 

      Doallo Biempica, Ramón; Fraguela, Basilio B.; Touriño, Juan; Zapata, Emilio L. (Springer, 1996)
      [Abstract] We present a parallel computational method for the QR decomposition with column pivoting of a sparse matrix by means of Modified Gram-Schmidt orthogonalization. Nonzero elements of the matrix M to be decomposed ...
    • Sparse Householder QR factorization on a mesh 

      Doallo Biempica, Ramón; Touriño, Juan; Zapata, Emilio L. (IEEE Computer Society, 1996-01)
      [Abstract] We analyze the parallelization of QR factorization by means of Householder transformations. This parallelization is carried out on a machine with a mesh topology (a 2-D torus to be more precise). We use a cyclic ...
    • Sparse Givens QR Factorization on a Multiprocessor 

      Touriño, Juan; Doallo Biempica, Ramón; Zapata, E.L. (IEEE Computer Society, 1996-06-01)
      [Abstract] We present a parallel algorithm for the QR factorization with column pivoting of a sparse matrix by means of Givens rotations. Nonzero elements of the matrix M to be decomposed are stored in a one dimensional ...
    • HPF-2 Support for Dynamic Sparse Computations 

      Asenjo Plaza, Rafael; Plata, Oscar; Touriño, Juan; Zapata, Emilio L.; Doallo Biempica, Ramón (Springer, 1998)
      [Abstract] There is a class of sparse matrix computations, such as direct solvers of systems of linear equations, that change the fill-in (nonzero entries) of the coefficient matrix, and involve row and column operations ...
    • A PVM Based Library for Sparse Matrix Factorizations 

      Touriño, Juan; Doallo Biempica, Ramón (Springer, 1998)
      [Abstract] We present 3LM, a C Linked List Management Library for parallel sparse factorizations on a PVM environment which takes into account the fill-in, an important drawback of sparse computations. It is restricted to ...
    • Characterization of message-passing overhead on the AP3000 multicomputer 

      Touriño, Juan; Doallo Biempica, Ramón (IEEE, 2001-09)
      [Abstract] The performance of the communication primitives of parallel computers is critical for the overall system performance. The characterization of the communication overhead is very important to estimate the global ...
    • Exploiting locality in the run-time parallelization of irregular loops 

      Martín Santamaría, María José; Singh, David E.; Touriño, Juan; Rivera, Francisco F. (C R C Press, LLC, 2002-12-10)
      [Abstract] The goal of this work is the efficient parallel execution of loops with indirect array accesses, in order to be embedded in a parallelizing compiler framework. In this kind of loop pattern, dependences can not ...
    • An Inspector-Executor Algorithm for Irregular Assignment Parallelization 

      Arenaz Silva, Manuel; Touriño, Juan; Doallo Biempica, Ramón (Springer, 2004)
      [Abstract] A loop with irregular assignment computations contains loop-carried output data dependences that can only be detected at run-time. In this paper, a load-balanced method based on the inspector-executor model is ...
    • Performance analysis of Java message-passing libraries on fast Ethernet, Myrinet and SCI clusters 

      López Taboada, Guillermo; Touriño, Juan; Doallo Biempica, Ramón (IEEE Computer Society, 2004-01-08)
      [Abstract] The use of Java for parallel programming on clusters according to the message-passing paradigm is an attractive choice. In this case, the overall application performance will largely depend on the performance ...
    • Compiler support for parallel code generation through kernel recognition 

      Arenaz Silva, Manuel; Touriño, Juan; Doallo Biempica, Ramón (IEEE Computer Society, 2004-06-07)
      [Abstract] Summary form only given. The automatic parallelization of loops that contain complex computations is still a challenge for current parallelizing compilers. The main limitations are related to the analysis of ...
    • Non-blocking Java Communications Support on Clusters 

      López Taboada, Guillermo; Touriño, Juan; Doallo Biempica, Ramón (Springer, 2006)
      [Abstract] This paper presents communication strategies for supporting efficient non-blocking Java communication on clusters. The communication performance is critical for the overall cluster performance. It is possible ...
    • Towards Low-Latency Model-Oriented Distributed Systems Management 

      Díaz, Iván; Touriño, Juan; Doallo Biempica, Ramón (Springer, 2007)
      [Abstract] Windows and Unix systems have been traditionally very different with regard to configuration storage and management. In this paper we have adapted our CIM-based model-driven management framework, AdCIM, to ...
    • Program Behavior Characterization Through Advanced Kernel Recognition 

      Arenaz Silva, Manuel; Touriño, Juan; Doallo Biempica, Ramón (Springer, 2007)
      [Abstract] Understanding program behavior is at the foundation of program optimization. Techniques for automatic recognition of program constructs (from now on, computational kernels) characterize the behavior of program ...
    • Efficient Java Communication Protocols on High-speed Cluster Interconnects 

      López Taboada, Guillermo; Touriño, Juan; Doallo Biempica, , Ramón (IEEE Computer Society, 2007-02-26)
      [Abstract] This paper presents communication strategies for achieving efficient parallel and distributed Java applications on clusters with high-speed interconnects. Communication performance is critical for the overall ...
    • High Performance Java Remote Method Invocation for Parallel Computing on Clusters 

      López Taboada, Guillermo; Teijeiro, Carlos; Touriño, Juan (IEEE Computer Society, 2007-11-12)
      [Abstract] This paper presents a more efficient Java remote method invocation (RMI) implementation for high-speed clusters. The use of Java for parallel programming on clusters is limited by the lack of efficient communication ...
    • Integrating the common information model with MDS4 

      Díaz, Iván; Fernández, G.; Martín Santamaría, María José; González, Patricia; Touriño, Juan (IEEE Computer Society, 2008-10-31)
      [Abstract] The management and monitoring of static and dynamic resources is a key issue in grid environments. Information models are an abstract representation of software and hardware aspects of these resources, a common ...
    • Ontological Con guration Management for Wireless Mesh Routers 

      Díaz, Iván; Popi, Cristian; Festor, Olivier; Touriño, Juan; Doallo Biempica, Ramón (Springer, 2009)
      [Abstract] Wireless mesh networks (WMNs) are a category of wireless networks that are self-organized, robust and which offer more flexible client coverage with less equipment requirements than wired networks. In WMNs, mesh ...
    • Performance Evaluation of MPI, UPC and OpenMP on Multicore Architectures 

      Mallón, Damián A.; López Taboada, Guillermo; Teijeiro, Carlos; Touriño, Juan; Fraguela, Basilio B.; Gómez, Andrés; Doallo Biempica, Ramón; Mouriño, José C. (Springer, 2009)
      [Abstract] The current trend to multicore architectures underscores the need of parallelism. While new languages and alternatives for supporting more efficiently these systems are proposed, MPI faces this new challenge. ...
    • NPB-MPJ: NAS Parallel Benchmarks Implementation for Message-Passing in Java 

      Mallón, Damián A.; López Taboada, Guillermo; Touriño, Juan; Doallo Biempica, Ramón (IEEE Computer Society, 2009-05-08)
      [Abstract] Java is a valuable and emerging alternative for the development of parallel applications, thanks to the availability of several Java message-passing libraries and its full multithreading support. The combination ...
    • Performance Evaluation of Unified Parallel C Collective Communications 

      López Taboada, Guillermo; Teijeiro, Carlos; Touriño, Juan; Fraguela, Basilio B.; Doallo Biempica, Ramón; Mouriño, José C.; Mallón, Damián A.; Gómez, Andrés (IEEE Computer Society, 2009-07-17)
      [Abstract] Unified Parallel C (UPC) is an extension of ANSI C designed for parallel programming. UPC collective primitives, which are part of the UPC standard, increase programming productivity while reducing the communication ...