The dynamic lattice liquid model was implemented as a simulation algorithm for simple liquids. This model works correctly for the density factor rho=1 and becomes a base for a parallel algorithm. Such an algorithm tak...
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The dynamic lattice liquid model was implemented as a simulation algorithm for simple liquids. This model works correctly for the density factor rho=1 and becomes a base for a parallel algorithm. Such an algorithm takes into account coincidences of elementary molecular motion attempts resulting in local cooperative structural transformations. In this paper general conditions for simulating simple liquids on various lattices are presented. Interdiffusion coefficients were directly monitored as changes of composition profiles with time for both athermal and interacting binary (AB) mixtures. In the athermal case, the coefficients of self-diffusion and interdiffusion are equal. For interacting binary mixtures the interdiffusion exhibits a thermally activated character. (C) 2003 American Institute of Physics.
The problem of finding possible limit reliability functions of basic systems is well known. For instance Gnedenko [Ann. Math. 44 (1943) 432-453] has found a class of possible limit reliability functions for series and...
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The problem of finding possible limit reliability functions of basic systems is well known. For instance Gnedenko [Ann. Math. 44 (1943) 432-453] has found a class of possible limit reliability functions for series and parallel systems. Smirnov [Trudy Matem Inst. im. V;A. Stelkova, 1949] has solved the problem for "k-out-of-n" systems. In this paper these two areas are brought together and a class of limit reliability functions of homogeneous series-"k-out-of-n" systems is presented. Moreover some applications are given as well. (C) 2002 Elsevier Science Inc. All rights reserved.
We present and analyze efficient new algorithms for generating a random variate distributed according to a dynamically changing set of N weights. The base version of each algorithm generates the discrete random variat...
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We present and analyze efficient new algorithms for generating a random variate distributed according to a dynamically changing set of N weights. The base version of each algorithm generates the discrete random variate in O(log* N) expected time and updates a weight in O(2(log)* (N)) expected time in the worst case. We then show how to reduce the update time to O(log* N) amortized expected time. We finally show how to apply our techniques to a lookup-table technique in order to obtain expected constant time in the worst case for generation and update. We give parallel algorithms for parallel generation and update having optimal processor-time product. Besides the usual application in computer simulation, our method can be usedto perform constant-time prediction in prefetching applications. We also apply our techniques to obtain an efficient dynamic algorithm for maintaining an approximate heap of N elements, in which each query is required to return an element whose value is within an epsilon multiplicative factor of the maximal element value. For epsilon = 1/polylog(N), each query, insertion, or deletion takes O(log log log N) time.
In this paper, we present a quasi-Newton parallel algorithm to solve the Inverse Additive Symmetric Eigenvalue Problem. Our approach differs from other state-of-the-art algorithms that use Newton type iteration, in th...
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ISBN:
(纸本)1892512416
In this paper, we present a quasi-Newton parallel algorithm to solve the Inverse Additive Symmetric Eigenvalue Problem. Our approach differs from other state-of-the-art algorithms that use Newton type iteration, in that we carry out the computation of the Jacobian matrix once in the first iteration, thus giving better performance than Newton algorithms even in the sequential case. In addition, our algorithm has been parallelized by using public domain software like ScaLAPACK and MPI, thus guaranteeing portability. Good performances have been obtained on a cluster of PCs connected through a Fast Ethernet network.
The numerical solution of 3D linear elasticity equations is considered. The problem is described by a coupled system of second order elliptic partial differential equations. This system is discretized by trilinear par...
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ISBN:
(纸本)3540006087
The numerical solution of 3D linear elasticity equations is considered. The problem is described by a coupled system of second order elliptic partial differential equations. This system is discretized by trilinear parallelepipedal finite elements. The Preconditioned Conjugate Gradient iterative method is used for solving of the large-scale linear algebraic systems arising after the Finite Element Method (FEM) discretization of the problem. Displacement decomposition technique is applied at the first step to construct a preconditioner using the decoupled block-diagonal part of the original matrix. Then circulant block-factorization is used for preconditioning of the obtained block-diagonal matrix. Both preconditioning techniques, displacement decomposition and circulant block-factorization, are highly parallelizable. A parallel algorithm is invented for the proposed preconditioner. The theoretical analysis of the execution time shows that the algorithm is highly efficient for coarse-grain parallel computer systems. A portable parallel FEM code based on MPI is developed. Numerical tests for real-life engineering problems in computational geomechanics are performed on a number of modern parallel computers: Cray T3E, Sunfire 6800, and Beowulf cluster. The reported speed-up and parallel efficiency well illustrate the parallel features of the proposed method and its implementation.
This paper presents a set of benchmarks and metrics for performance reporting in explicit state parallel model checking algorithms. The benchmarks are selected for controllability, and the metrics are chosen to measur...
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We present a randomized EREW PRAM algorithm to find a minimum spanning forest in a weighted undirected graph. On an n-vertex graph the algorithm runs in o((log n)(1+epsilon)) expected time for any epsilon > 0 and p...
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We present a randomized EREW PRAM algorithm to find a minimum spanning forest in a weighted undirected graph. On an n-vertex graph the algorithm runs in o((log n)(1+epsilon)) expected time for any epsilon > 0 and performs linear expected work. This is the first linear-work, polylog-time algorithm on the EREW PRAM for this problem. This also gives parallel algorithms that perform expected linear work on two general-purpose models of parallel computation-the QSM and the BSP.
A parallel propagation algorithm was applied to the decoding of convolutional codes. The performance of the algorithm was demonstrated by a numerical method similar to the density evaluation.
A parallel propagation algorithm was applied to the decoding of convolutional codes. The performance of the algorithm was demonstrated by a numerical method similar to the density evaluation.
We describe a parallel model-checking algorithm for the fragment of the μ-calculus that allows one alternation of minimal and maximal fixed-point operators. This fragment is also known as L2μ. Since LTL and CTL* can...
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At the Center for Computational Electromagnetics at the University of Illinois, we recently solved a very-large-scale electromagnetic scattering problem. We computed the bistatic radar cross-section of a full-size air...
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At the Center for Computational Electromagnetics at the University of Illinois, we recently solved a very-large-scale electromagnetic scattering problem. We computed the bistatic radar cross-section of a full-size aircraft at 8 GHz, involving the solution of a dense matrix equation with nearly 10.2 million unknowns. We regarded this as the "ultimate test" of a massively parallel implementation of the Multilevel Fast Multipole Algorithm (MLFMA), called ScaleME. In this paper, we narrate the technical difficulties faced and the experience gained from a very informal point of view. We shall describe the various methods developed for surmounting each of the obstacles.
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