Computers

  2010 SEP 2 - (VerticalNews.com) -- According to a study from Zurich, Switzerland, "Evolution and structure of very large networks has attracted considerable attention in recent years. In this paper we study a possibility to simulate stochastic processes which move edges in a network leading to a scale-free structure."

  "Scale-free networks are characterized by a ''fat-tail'' degree distribution with considerably higher presence of so called hubs - nodes with very high degree. To understand and predict very large networks it is important to study the possibility of parallel simulation. We consider a class of stochastic processes which keeps the number of edges in the network constant called equilibrium networks. This class is characterized by a preferential selection where the edge destinations are chosen according to a preferential function f(k) which depends on the node degree k. For this class of stochastic processes we prove that it is difficult if not impossible to design an exact parallel algorithm if the function f(k) is monotonous with an injective derivative. However, in the important case where f(k) is linear we present a fully scalable algorithm with almost linear speedup," wrote T. Hruz and colleagues ...read more

  2010 SEP 2 - (VerticalNews.com) -- According to recent research from Russia, "A parallel algorithm for solving a series of matrix equations with a constant tridiagonal matrix and different right-hand sides is proposed and studied. The process of solving the problem is represented in two steps."

  "The first preliminary step is calculating some rows of the inverse matrix of system of linear algebraic equations. The second step consists in calculating solutions for all right-hand sides. For reducing the communication interactions, based on the formulated and proved the main Gaussian Parallel Elimination Theorem for tridiagonal system of equations, we propose an original algorithm for calculating share components of the solution vector. Theoretical estimates validating the efficiency of the approach for both the common- and distributed-memory supercomputers are obtained. Direct and iterative methods of solving a 2D Poisson equation, which include procedures of tridiagonal matrix inversion, are realized using the MPI paradigm," wrote A.V. Terekhov and colleagues ...read more

  2010 SEP 2 - (VerticalNews.com) -- "We present efficient parallel algorithms for multiple-precision arithmetic operations of more than several million decimal digits on distributed-memory parallel computers," researchers in Tsukuba, Japan report.

  "A parallel implementation of floating-point real FFT-based multiplication is used, since the key operation for fast multiple-precision arithmetic is multiplication. The operation for releasing propagated carries and borrows in multiple-precision addition, subtraction and multiplication was also parallelized," wrote D. Takahashi and colleagues, University of Tsukuba ...read more