High-dimensional problems arising from complex robotic systems test the limits of current motion planners and require the development of efficient distributed motion planners that take full advantage of all the availa...
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High-dimensional problems arising from complex robotic systems test the limits of current motion planners and require the development of efficient distributed motion planners that take full advantage of all the available resources. This paper shows how to effectively distribute the computation of the Sampling-based Roadmap of Trees (SRT) algorithm using a decentralized master-client scheme. The distributed SRT algorithm allows us to solve very high-dimensional problems that cannot be efficiently addressed with existing planners. Our experiments show nearly linear speedups with eighty processors and indicate that similar speedups can be obtained with several hundred processors.
A bipartite graph G is bipancyclic if G has a cycle of length l for every even 4 /spl les/l/spl les/|V(G)|. For a bipancyclic graph G and any edge e, G is edge-bipancyclic if e lies on a cycle of any even length I of ...
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A bipartite graph G is bipancyclic if G has a cycle of length l for every even 4 /spl les/l/spl les/|V(G)|. For a bipancyclic graph G and any edge e, G is edge-bipancyclic if e lies on a cycle of any even length I of G. In this paper, we show that the bubble-sort graph B/sub n/ is bipancyclic for n/spl ges/ 4, and also show that it is edge-bipancyclic for n/spl ges/5. To obtain this results, we also prove that we can construct a hamiltonian cycle of B/sub n/ that contains given two nonadjacent edges. Assume that F is the subset of E(B/sub n/). We prove that B/sub n /-F is bipancyclic whenever n /spl ges/4 and |F|/spl les/ n-3. Since B/sub n/ is a (n-1)-regular graph, this result is optimal in the worst case.
Clustering of data has numerous applications and has been studied extensively. Though most of the algorithms in the literature are sequential, many parallel algorithms have also been designed. In this paper we present...
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ISBN:
(纸本)1880843528
Clustering of data has numerous applications and has been studied extensively. Though most of the algorithms in the literature are sequential, many parallel algorithms have also been designed. In this paper we present parallel algorithms with better performance than known algorithms. We consider algorithms that work well in the worst case as well as algorithms with good expected performance.
In this paper, we are proposing more efficient one-step negabinary signed-digit algorithms for the addition/subtraction operations. It is shown that by using digits grouping of the negabinary signed-digits, a huge red...
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ISBN:
(纸本)081945415X
In this paper, we are proposing more efficient one-step negabinary signed-digit algorithms for the addition/subtraction operations. It is shown that by using digits grouping of the negabinary signed-digits, a huge reduction of the number of the symbolic substitution computation rules involved in the arithmetic computations will be achieved. Further, to increase the information storage density, one-step trinary negabinary (using base = -3) and negabinary quaternary (using base = -4) signed-digit will be proposed. The proposed algorithms are very suitable for optical implementation. Various holographic and nonholographic methods based on symbolic substitution content addressable memory (CAM) are suggested for optoelectronic implementation. Among them, the method of joint spatial encoding technique and incoherent optical correlator to act as a shared CAM will be presented.
The Building Block Layout (BBL) becomes a more and more important approach for VLSI physical design. In this paper, based on the BBL floorplan problem, we discussed several parallel Simulated Annealing (SA) strategies...
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ISBN:
(纸本)0780386477
The Building Block Layout (BBL) becomes a more and more important approach for VLSI physical design. In this paper, based on the BBL floorplan problem, we discussed several parallel Simulated Annealing (SA) strategies. Two parallel simulated annealing algorithms are realized, using sequence-pair (SP) as the representation. parallel algorithm can be used either to speed up a problem or to achieve a higher accuracy of solutions to a problem. In this work we are interested in the latter goal. The results from the experiment indicate that the proposed method parallelizes the routine of state transitions in SA to obtain better states efficiently.
One of the main reasons for using parallel evolutionary algorithms (PEAs) is to obtain efficient algorithms with an execution time much lower than that of their sequential counterparts in order, e.g.. to tackle more c...
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One of the main reasons for using parallel evolutionary algorithms (PEAs) is to obtain efficient algorithms with an execution time much lower than that of their sequential counterparts in order, e.g.. to tackle more complex problems. This naturally leads to measuring the speedup of the PEA. PEAs have sometimes been reported to provide super-linear performances for different problems, parameterizations, and machines. Super-linear speedup means that using "m" processors leads to an algorithm that runs more than "m" times faster than the sequential version. However. reporting super-linear speedup is controversial, especially for the "traditional" research community, since some non-orthodox practices could be thought of being the cause for this result. Therefore, we begin by offering a taxonomy for speedup, in order to clarify what is being measured. Also, we analyze the sources for such a scenario in this paper. Finally, we study an assorted set of results. Our conclusion is that super-linear performance is possible for PEAs, theoretically and in practice. both in homogeneous and in heterogeneous parallel machines. (C) 2001 Elsevier Science B.V, All rights reserved.
We present an optimal parallel randomized algorithm for the Voronoi diagram of a set of n nonintersecting (except possibly at endpoints) line segments in the plane. Our algorithm runs in O(log n) time with high probab...
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We present an optimal parallel randomized algorithm for the Voronoi diagram of a set of n nonintersecting (except possibly at endpoints) line segments in the plane. Our algorithm runs in O(log n) time with high probability using O (n) processors on a CRCW PRAM. This algorithm is optimal in terms of work done since the sequential time bound for this problem is O(n log n). Our algorithm improves by an O(log n) factor the previously best known deterministic parallel algorithm, given by Goodrich, O'Dunlaing, and Yap, which runs in O(log(2) n) time using O(n) processors. We obtain this result by using a new "two-stage" random sampling technique. By choosing large samples in the first stage of the algorithm, we avoid the hurdle of problem-size "blow-up" that is typical in recursive parallel geometric algorithms. We combine the two-stage sampling technique with efficient search and merge procedures to obtain an optimal algorithm. This technique gives an alternative optimal algorithm for the Voronoi diagram of points as well (all other optimal parallel algorithms for this problem use the transformation to three-dimensional half-space intersection).
A new parallel algorithm for route assignments in Benes-Clos networks is studied in this paper. Most known sequential route assignment algorithms, such as the looping algorithm, are designed for circuit switching syst...
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A new parallel algorithm for route assignments in Benes-Clos networks is studied in this paper. Most known sequential route assignment algorithms, such as the looping algorithm, are designed for circuit switching systems where the switching configuration can be rearranged at relatively low speed. In packet switching systems, switch fabrics must be able to provide internally conflict-free paths simultaneously, and accommodate packets requesting connections in real time as they arrive at the inputs. In this paper, we develop a parallel routing algorithm for Benes networks by solving a set of Boolean equations which are derived from the connection requests and the symmetric structure of the networks. Our approach can handle partial permutations easily. The time complexity of our algorithm is O(log(2) N), where N is the network size. We also extend the algorithm and show that it can be applied to the Clos networks if the number of central modules is M = 2(m), where m is a positive integer. The time complexity is O(log N x log M) in this case.
Let T=(V, E) be a tree with vertex set V and edge set E. Let n=|V|. Each e/spl isin/E has a non-negative length. In this paper, we first present an algorithm on the CREW PRAM for solving the V/V/r-dominating set probl...
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ISBN:
(纸本)0769517609
Let T=(V, E) be a tree with vertex set V and edge set E. Let n=|V|. Each e/spl isin/E has a non-negative length. In this paper, we first present an algorithm on the CREW PRAM for solving the V/V/r-dominating set problem on T, where r/spl ges/0 is a real number. The algorithm requires O(log/sup 2/ n) time using O(n log n) work. Applying this algorithm as a procedure for testing feasibility, the V/V/p-center problem on the CREW PRAM is solved in O(log/sup 2/ n) time using O(n log/sup 2/ n) work, where p/spl ges/1 is an integer. Previously, He and Yesha had proposed algorithms on the CREW PRAM for special cases of the V/V/r-dominating set and the V/V/p-center problems, in which r is an integer and the lengths of all edges are 1. Their V/V/r-dominating set algorithm requires O(log n log log n) time using O(n log n log log n) work; and their V/V/p-center algorithm requires O(log/sup 2/ n log log n) time using O(n log/sup 2/ n log log n) work. As compared with He and Yesha's results, ours are more general and more efficient from the aspect of work.
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