We present an efficient and scalable coarse grained multicomputer (CGM) coloring algorithm that colors a graph G with at most Delta + 1 colors where A is the maximum degree in G. This algorithm is given in two variant...
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We present an efficient and scalable coarse grained multicomputer (CGM) coloring algorithm that colors a graph G with at most Delta + 1 colors where A is the maximum degree in G. This algorithm is given in two variants: randomized and deterministic. We show that on a p-processor CGM model the proposed algorithms require a parallel time of O(\G\/p) and a total work and overall communication cost of O(\G\). These bounds correspond to the average case for the randomized version and to the worst case for the deterministic variant. (C) 2003 Elsevier B.V. All rights reserved.
Recent developments in magnetic disk technology have made stored-integral techniques competitive with the currently more widely used direct methods, which involve the recalculation of the basic two-electron integrals....
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Recent developments in magnetic disk technology have made stored-integral techniques competitive with the currently more widely used direct methods, which involve the recalculation of the basic two-electron integrals. We present efficient conventional (all integrals stored) and semidirect Hartree-Fock and DFT algorithms with data compression for single-processor and distributed memory parallel computers, and compare them with the corresponding direct algorithms. On inexpensive modem personal computer-based hardware, the stored integral method is up to three times more efficient than the direct method in terms of total elapsed job time. (C) 2002 Wiley Periodicals, Inc.
Many of the operations to eliminate complaints concerning respiration impairments fail. In order to improve the success rate, it is important to recognize the responsiveness of the flow field within the nasal cavities...
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Many of the operations to eliminate complaints concerning respiration impairments fail. In order to improve the success rate, it is important to recognize the responsiveness of the flow field within the nasal cavities. Therefore, we are developing a computer assisted surgery (CAS) system that combines computational fluid dynamics (CFD) and virtual reality (VR) technology. However, the primary prerequisite for VR-based applications is real-time interaction. A single graphics workstation is not capable of satisfying this condition and of simultaneously calculating flow features employing the huge CFD data set. In this paper, we will present our approach of a distributed system that relieves the load on the graphics workstation and makes use of an "off-the-shelf'' parallel Linux cluster calculating streamlines. Moreover, we introduce first results and discuss remaining difficulties.
In this paper we describe a parallel algorithm using the BSP/CGM model (Bulk Synchronous parallel/Coarse Grained Multicomputer) to obtain the Euler tours in graphs. It is based on the PRAM (parallel Random Access Mach...
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ISBN:
(纸本)0769520464
In this paper we describe a parallel algorithm using the BSP/CGM model (Bulk Synchronous parallel/Coarse Grained Multicomputer) to obtain the Euler tours in graphs. It is based on the PRAM (parallel Random Access Machine) algorithm by Caceres et al. For an input graph of n vertices and m edges, the algorithm requires local computation time of O((m + n)/p), O((m + n'p) memory and O(log p) communication rounds, where p is the number of processors. To our knowledge there are no other parallel algorithms under the coarse-grained models for the Euler tours in graphs. The proposed algorithm is implemented using MPI (Message Passing Interface) and the C language. The parallel program runs on a Beowulf with 66 nodes. The implementation results confirm the theoretical complexity results of the algorithm.
Min-wise independence is a recently introduced notion of limited independence, similar in spirit to pairwise independence. The latter has proven essential for the derandomization of many algorithms. Here we show that ...
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This paper explores the prefix operation on a message-passing fully connected multicomputer with multiport postal communication. We present an exact communication lower bound for the prefix operation on the model. Two...
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This paper explores the prefix operation on a message-passing fully connected multicomputer with multiport postal communication. We present an exact communication lower bound for the prefix operation on the model. Two efficient parallel prefix algorithms are also presented;they are optimal in terms of the number of communication steps. For an input of size n, one of the algorithms using n processors is also time-optimal;the other algorithm using p < n processors can be cost-optimal and can achieve linear speedup.
Within the last several years, a number of parallel algorithms for the join operation have been proposed. However, almost all of these algorithms do not take advantage of the underlying parallel storage structures or ...
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Within the last several years, a number of parallel algorithms for the join operation have been proposed. However, almost all of these algorithms do not take advantage of the underlying parallel storage structures or data declustering methods of the operand relations. The paper introduces the concept of parallel storage structure or declustering aware parallel join algorithm. Two classes of parallel join algorithms, which take advantage of the underlying parallel B/sup +/-tree index, are proposed and analyzed. One class is based on the range-partition strategy. The other is based on the hash-partition strategy. The parallel execution times of the algorithms are linearly proportional to max{N/P, M/P}, where N and M are the numbers of tuples of the operand relations and P is the number of processing nodes. The proposed parallel join algorithms are compared with well known parallel join algorithms in practice. Theoretical and experimental results show that the proposed algorithms are more efficient than others in case of at least one operand relation having a parallel B/sup +/-tree index on the join attributes.
How to discover high-level knowledge modeled by complicated functions, ordinary differential equations and difference equations in databases automatically is a very important and difficult task in KDD research. In thi...
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How to discover high-level knowledge modeled by complicated functions, ordinary differential equations and difference equations in databases automatically is a very important and difficult task in KDD research. In this paper, high-level knowledge modeled by ordinary differential equations (ODEs) is discovered in dynamic data automatically by an asynchronous parallel evolutionary modeling algorithm (APHEMA). A numerical example is used to demonstrate the potential of APEA. The results show that the dynamic models discovered automatically in dynamic data by computer sometimes can compare with the models discovered by human.
Existing position-based unicast routing algorithms, which forward packets in the geographic direction of the destination, require that the forwarding node knows the positions of all neighbors in its transmission range...
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Poset belief propagation, or PBP, is a flexible generalization of ordinary belief propagation which can be used to (approximately) solve many probabilistic inference problems. In this paper, we summarize some experime...
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Poset belief propagation, or PBP, is a flexible generalization of ordinary belief propagation which can be used to (approximately) solve many probabilistic inference problems. In this paper, we summarize some experimental results comparing the performance of PBP to conventional BP techniques.
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