Multi-step, multi-directional parallel variable metric (PVM) methods for unconstrained optimization problems are presented in this paper. These algorithms generate several VM directions at each iteration, dierent line...
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We examine existing parallel algorithms for detection of strongly connected components and discuss their applicability to the case when the graph to be decomposed is given implicitly. In particular, we list individual...
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ISBN:
(纸本)9783540709510
We examine existing parallel algorithms for detection of strongly connected components and discuss their applicability to the case when the graph to be decomposed is given implicitly. In particular, we list individual techniques that parallel algorithms for SCC detection are assembled from and show how to assemble a new more efficient algorithm for solving the problem. In the paper we also report on a preliminary experimental study we did to evaluate the new algorithm.
In this paper we describe efficient parallel algorithms for computing canonical chains and canonical anti-chains partition of a set of points on a plane. The problem to compute chain and anti-chain partition is of int...
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ISBN:
(纸本)9781424418893
In this paper we describe efficient parallel algorithms for computing canonical chains and canonical anti-chains partition of a set of points on a plane. The problem to compute chain and anti-chain partition is of interest in VLSI design [LS92], computational geometry [MW92] and in computational molecular biology [Pev01]. A new affine transformation on the set of points is defined which transforms chains in the original point set into anti-chains in the transformed point set.
Pairings are useful tools in cryptography and efficient implementations play a critical role in their usage, where Miller's algorithms are the main method for all pairings. As an alternative approach, elliptic net...
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ISBN:
(纸本)9789819750245;9789819750252
Pairings are useful tools in cryptography and efficient implementations play a critical role in their usage, where Miller's algorithms are the main method for all pairings. As an alternative approach, elliptic nets were first employed to evaluate Tate pairings and generalized to the hyperelliptic nets for Tate pairings on hyperelliptic curves. In this work, for hyperelliptic pairings derived from rational functions, we establish the unitary formulae in terms of hyperelliptic nets. Afterwards, for genus-2 hyperelliptic pairings, we construct a parallel Double-and-Add algorithm on the minimal block. In particular, all terms in new blocks, having irrelevant formulae on current blocks, can be evaluated with 12 processors in parallel, thus the explicit loop cost reduces to 4M' (multiplications in extension fields) with 276 parallel processors. As an additional merit, Double and Double-Add algorithms invoke analogous operations such that our method avoids extra additions in Miller's algorithms.
A phylogenetic tree construction is one of the most important problems in computational biology. From computational point of view it is also one of the most difficult problem because of its intrinsic intractability. E...
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ISBN:
(纸本)3540219463
A phylogenetic tree construction is one of the most important problems in computational biology. From computational point of view it is also one of the most difficult problem because of its intrinsic intractability. Efficient algorithms are known only for some special cases of the problem which are unrealistic from biological point of view. Many algorithms are known for the problem, but since the problem is hard, they are usually heuristics. In this paper we present three exact parallel algorithms for the problem. They have been tested in computational experiment ran on SUN Fire computer.
parallel algorithms and strategies are outlined for optimal design of frame structures subjected to dynamic earthquake loading. parallelism is extracted in six areas: substructuring of the total domain, solution of li...
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We present adaptive and cost-optimal parallel algorithms for generating 1) all subsets of the set {1,…,n}, 2) all limited size subsets (each subset has at most m elements for a given m), and 3) all partitions of the ...
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A motion panorama is an efficient and compact representation of the underlying video. However, the motion panorama construction process is computationally intensive and hence extremely time consuming. Addressing this ...
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ISBN:
(纸本)0769526373
A motion panorama is an efficient and compact representation of the underlying video. However, the motion panorama construction process is computationally intensive and hence extremely time consuming. Addressing this issue is crucial when one considers using motion panoramas in a real-time environment such as live video transmission. We present two parallel algorithms for motion panorama construction, namely, the shared memory parallel algorithm (SMPA) that uses POSIX threads and the distributed memory parallel algorithm (DMPA) that uses MPI. The parallel algorithms are tested on real videos. Experimental results show that the SMPA achieves linear speedup in most cases whereas the DMPA suffers from reduced efficiency when the number of processors exceeds 8.
This paper investigates two methods of exploiting parallel architectures in order to efficiently extract reduced-order models for passive high-frequency integrated devices. Due to the high frequencies involved, all th...
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ISBN:
(纸本)9781457705076
This paper investigates two methods of exploiting parallel architectures in order to efficiently extract reduced-order models for passive high-frequency integrated devices. Due to the high frequencies involved, all the effects of electromagnetic fields must be taken into account, but this leads to very large models which have to be reduced. We use an efficient technique, based on Vector Fitting, to extract these models with minimal computational effort, and we propose two methods of mapping the tasks on a parallel architecture.
A few parallel algorithms for solving triangular systems resulting from parallel factorization of sparse linear systems have been proposed and implemented recently. We present a detailed analysis of parallel complexit...
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ISBN:
(纸本)0897918622
A few parallel algorithms for solving triangular systems resulting from parallel factorization of sparse linear systems have been proposed and implemented recently. We present a detailed analysis of parallel complexity and scalability of the best of these algorithms and the results of its implementation on up to 256 processors of the Cray T3D parallel computer. It has been a common belief that parallel sparse triangular solvers are quite unscalable due to a high communication to computation ratio. Our analysis and experiments show that, although not as scalable as the best parallel sparse Cholesky factorization algorithms, parallel sparse triangular solvers can yield reasonable speedups in runtime on hundreds of processors. We also show that for a wide class of problems, the sparse triangular solvers described in this paper are optimal and are asymptotically as scalable as a dense triangular solver.
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