We compute the weight enumerators of various quadratic residue (QR) codes over F/sub 2/ and F/sub 3/, together with certain codes of related families like the duadic codes. We use a parallel algorithm to find the numb...
详细信息
We compute the weight enumerators of various quadratic residue (QR) codes over F/sub 2/ and F/sub 3/, together with certain codes of related families like the duadic codes. We use a parallel algorithm to find the number of codewords of a given (not too high) weight, from which we deduce by usual classical methods for selfdual and isodual codes over F/sub 2/ and F/sub 3/ their associated, previously unknown, weight enumerators. We compute weight enumerators for lengths as high as 152 for binary codes (except for n=138 for which one lacks the number of codewords of weight 34) and 84 for ternary codes.
In this paper, we propose a new algorithm, named Distributed Max-Miner (DMM), for mining maximal frequent itemsets from databases. A frequent itemset is maximal if none of its supersets is frequent. DMM requires very ...
详细信息
ISBN:
(纸本)9780780384309
In this paper, we propose a new algorithm, named Distributed Max-Miner (DMM), for mining maximal frequent itemsets from databases. A frequent itemset is maximal if none of its supersets is frequent. DMM requires very low communication and synchronization overhead in distributed computing systems. DMM has the local mining phase and the global mining phase. During the local mining phase, each node mines the local database to discover the local maximal frequent itemsets, then they form a set of maximal candidate itemsets for the top-down search in the subsequent global mining phase. A new prefix-tree data structure is developed to facilitate the storage and counting of the global candidate itemsets of different sizes. This global mining phase using the prefix-tree can work with any local mining algorithm. We implemented DMM on a cluster of workstations and evaluated its performance for various cases. DMM demonstrates better performance than other sequential and parallel algorithms, and its performance is quite scalable, even when there are large maximal frequent itemsets (i.e., long patterns) in databases.
Wavelet analysis has received considerable interest in the recent years because of its efficiency in the several practical applications. Image processing for wavelet transformation is considered as one of the most pow...
详细信息
Wavelet analysis has received considerable interest in the recent years because of its efficiency in the several practical applications. Image processing for wavelet transformation is considered as one of the most powerful methods that provide a good quality of results. However, its implementation may be too time-consuming accordingly to the problem size. parallel processing can be a solution to speed up wavelet transformation programs. In this context, and in order to have a quick image compression/decompression program based on 1D wavelet transformation, we have designed three parallel algorithms that where implemented on an IBM RS6000/SP machine. The first parallel algorithm exploits control parallelism it was developed with OpenMP and executed on one four-processor node. The two others exploit data parallelism and were developed with MPI directives. Finally, we present an evaluation of these algorithms based on an experimental study.
In this paper a model of a versatile associative graph processor called AGP is proposed. The model can work both in bit-serial and in bit-parallel mode and enables simultaneous search for a set of comparands and selec...
详细信息
In this paper a model of a versatile associative graph processor called AGP is proposed. The model can work both in bit-serial and in bit-parallel mode and enables simultaneous search for a set of comparands and selection of the search types. In addition it has some built-in operations designed for associative graph algorithms. The selected functions and basic procedures of this model are described and its possible architecture is discussed.
Summary form only given. Evolutionary algorithms (EAs) are applied to solve the radio network design problem (RND). The task is to find the best set of transmitter locations in order to cover a given geographical regi...
详细信息
Summary form only given. Evolutionary algorithms (EAs) are applied to solve the radio network design problem (RND). The task is to find the best set of transmitter locations in order to cover a given geographical region at an optimal cost. Usually, parallel EAs are needed in order to cope with the high computational requirements of such a problem. Here, we try to develop and evaluate a set of sequential and parallel genetic algorithms (GAs) in order to solve efficiently the RND problem. The results show that our distributed steady state GA is an efficient and accurate tool for solving RND that even outperforms existing parallel solutions. The sequential algorithm performs very efficiently from a numerical point of view, although the distributed version is much faster, with an observed linear speedup.
We investigate numerical methods for passive model reduction of linear dynamical systems. This is an important task in circuit simulation when modeling parasitic effects of interconnect. We will show how positive real...
详细信息
We investigate numerical methods for passive model reduction of linear dynamical systems. This is an important task in circuit simulation when modeling parasitic effects of interconnect. We will show how positive real balancing, based on balancing the solutions of two algebraic Riccati equations, can be used for passive model reduction of large-scale systems on parallel computers. Numerical experiments demonstrate the performance of the parallel algorithms using several examples from circuit simulation.
Summary form only given. In multiprogrammed systems, synchronization often turns out to be a performance bottleneck and the source of poor fault-tolerance. Wait-free and lock-free algorithms can do without locking mec...
详细信息
Summary form only given. In multiprogrammed systems, synchronization often turns out to be a performance bottleneck and the source of poor fault-tolerance. Wait-free and lock-free algorithms can do without locking mechanisms, and therefore do not suffer from these problems. We present an efficient almost wait-free algorithm for parallel accessible hashtables, which promises more robust performance and reliability than conventional lock-based implementations. Our solution is as efficient as sequential hashtables. It can easily be implemented using C-like languages and requires on average only constant time for insertion, deletion or accessing of elements. The algorithm allows the hashtables to grow and shrink when needed. A true problem of wait-free and lock-free algorithms is that they are hard to design correctly, even when apparently straightforward. The reason for this is that processes can execute all statements in every conceivable order. Since our algorithm is quite large and rather complex, we turned to the interactive theorem prover PVS to prove safety of our algorithm, which we could not have done reliably by hand. To our knowledge no algorithms of comparable complexity have ever been mechanically verified. Wait-freedom is shown informally.
BAOR (block accelerated over-relaxation) method, now commonly used in solving engineering problems involving block tridiagonal coefficient matrix, is not suitable for parallel computing. We proposed a parallel algorit...
详细信息
BAOR (block accelerated over-relaxation) method, now commonly used in solving engineering problems involving block tridiagonal coefficient matrix, is not suitable for parallel computing. We proposed a parallel algorithm that like BAOR algorithm is good in convergence, but that unlike BAOR algorithm is suitable for parallel computing. We explained why BAOR algorithm is not suitable for parallel computing. This understanding helps us to make our algorithm suitable for parallel computing. We gave one illustrative example. The iterative time needed by our algorithm is roughly the same as that needed by BAOR algorithm. These results indicate preliminarily that our algorithm is effective and feasible.
To meet the real time requirements an interpolation free, parallel algorithm for the fast Radon transform (FRT) and inverse FRT (IFRT) is proposed. The proposed method solves all the important problems associated with...
详细信息
To meet the real time requirements an interpolation free, parallel algorithm for the fast Radon transform (FRT) and inverse FRT (IFRT) is proposed. The proposed method solves all the important problems associated with the previous interpolation free FRT and IFRT algorithm and reduces the number of computations and algorithmic complexities significantly. The proposed algorithm is highly regular and we also describe a methodology to design a dedicated parallel processing architecture from the view point of its efficient implementation.
A parallel Hough transform algorithm on linear array with reconfigurable pipeline bus system (LARPBS) is presented. Utilizing the strong communication and computation ability of LARPBS, the algorithm can contract and ...
详细信息
A parallel Hough transform algorithm on linear array with reconfigurable pipeline bus system (LARPBS) is presented. Utilizing the strong communication and computation ability of LARPBS, the algorithm can contract and count the foreground pixels on each line. Suppose the number of θ values considered is m, the algorithm can complete Hough transform for an image with n×n pixels in O(1) time using mn2 processors and get optimal speed and efficiency. We also illustrate how to partition and perform the algorithm on a LARPBS with less than mn2 processors, thus show the algorithm is highly scalable.
暂无评论