This paper presents part of the work being carried out to obtain parallel versions of the main SLICOT routines for model reduction. It is focused on the parallel solution of standard Lyapunov equations obtaining the C...
详细信息
This paper presents part of the work being carried out to obtain parallel versions of the main SLICOT routines for model reduction. It is focused on the parallel solution of standard Lyapunov equations obtaining the Cholesky factor of the controllability and observability Grammians. This operation is an important basis for model reduction methods. Routines from the standard libraries BLAS, LAPACK, SLICOT, PBLAS and ScaLAPACK have been used whenever possible in the parallelisation process. However, it has been necessary to develop some new routines. Experimental results obtained using a cluster of PC's are shown.
An efficient parallel approach for the computation of the eigenvalue of smallest absolute magnitude of sparse real and complex matrices is provided. The proposed strategy tries to improve the efficiency of the reverse...
详细信息
An efficient parallel approach for the computation of the eigenvalue of smallest absolute magnitude of sparse real and complex matrices is provided. The proposed strategy tries to improve the efficiency of the reverse power method. At each inverse power iteration the linear system is solved either by the conjugate gradient scheme (symmetric case) or by the Bi-CGSTAB method (symmetric case). Both solvers are preconditioned employing the approximate inverse factorization and thus are easily parallelized. The satisfactory speed-ups obtained on the CRAY T3E supercomputer show the high degree of parallelization reached by the proposed algorithm.
This paper introduces the developing situation of decision tree during several years. During these years, ID3 algorithm has been in the highest flight in decision tree. ID3 makes use of information entropy as heuristi...
详细信息
ISBN:
(纸本)0780375084
This paper introduces the developing situation of decision tree during several years. During these years, ID3 algorithm has been in the highest flight in decision tree. ID3 makes use of information entropy as heuristic to select "excellent attribution" at each node, so it can get smaller depth but not the proper width of the tree. That is to say that if the width is large, no matter what small of decision tree is, the leaf node will not be small. It is very important that smaller nodes get higher classify precision for decision tree. This paper provides two algorithms, which can avoid the deficiency of ID3 and reduce the width of the tree to get the better result, the one is PID based on probability, and the other one is EMID based on entropy.
When dealing with high‐frequency time series, statistical procedures giving reliable estimates of unknown parameters and forecasts in real time are required. This is why recursive estimation methods are usually prefe...
详细信息
LetBbe a set ofnbblue points and R a set of nrred points in the plane, where nb+ nr= n. A blue point b and a red point r can be matched if r dominates b, that is, if x(b) ≤ x(r) and y( b) ≤ y(r). We consider the pro...
详细信息
LetBbe a set ofnbblue points and R a set of nrred points in the plane, where nb+ nr= n. A blue point b and a red point r can be matched if r dominates b, that is, if x(b) ≤ x(r) and y( b) ≤ y(r). We consider the problem of finding a maximum cardinality matching between the points in B and the points in R. We give an adaptive parallel algorithm to solve this problem that runs in O(log2n) time using the CREW PRAM with O(n2+∊/log n) processors for some ∊,0 < ∊ < *** follows that finding the minimum number of colors to color a trapezoid graph can be solved within these resource bounds
In this paper, we take initial steps toward developing energy-efficient broadcast algorithms for ad hoc wireless networks that operate under changing connectivity conditions. Such algorithms need to be distributed. An...
详细信息
The Broadcast Incremental Power (BIP) algorithm is a centralized heuristic for the construction of energy-efficient broadcast trees in wireless networks. In this paper, we discuss the issues associated with the develo...
详细信息
Dynamic programming is an important combinatorial optimization technique that has been widely used in various fields such as control theory, operations research, computational biology and computer science. Many author...
详细信息
Dynamic programming is an important combinatorial optimization technique that has been widely used in various fields such as control theory, operations research, computational biology and computer science. Many authors have described parallel dynamic programming algorithms for the family of multistage problems. More scarce is the literature for the more general class of problems where dependences appear between non-consecutive stages. Among the important problems falling in this class is the RNA base pairing problem. In this study we propose a new parallel scheme for a large class of recurrences with triangular iteration space and nonuniform dependences that includes the RNA base pairing problem. We derive two different instances of this scheme that correspond to an horizontal and a vertical traverse of the iteration domain. We develop and extend the tiling approach for this particular class. We formulate and analytically solve the optimization problem determining the tile size that minimizes the total execution time of the tiled program on a distributed memory parallel machine. Our analyze is based on the BSP model, which assures the portability of the obtained results. The computational experiments carried out on the CRAY T3E behave according to the predictions of our theoretical model.
The utilization of multiple DSP systems for parallel processing in computationally demanding applications is growing fast. The field of 2-D imaging and multidimensional signal processing is a good candidate for parall...
详细信息
One approach to transformation based compression is the Matching Pursuit Projection (MPP). MPP or variants of it have been suggested for designing image compression and video compression algorithms and have been among...
详细信息
ISBN:
(纸本)0819444146
One approach to transformation based compression is the Matching Pursuit Projection (MPP). MPP or variants of it have been suggested for designing image compression and video compression algorithms and have been among the top performing submissions within the MPEG-4 standardization process. In the case of still image coding, the MPP approach has to be paid with an enormous computational complexity. In this work we discuss sequential, as well as parallel speedup techniques of a MPP image coder which is competitive in terms of rate-distortion performance.
暂无评论