Browsing by Author "Chang, PY"

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An approach to designing modular extensible linear arrays for regular algorithms
(1998-02-01)
Chang, PY
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Tsay, JC
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工學院
;
College of Engineering
The purpose of this paper is to describe a new method to design unidirectional modular extensible linear arrays far regular algorithms. The time complexity of our method is polynomial and depends only on the number of dimensions of the regular algorithm. The designed linear array is asymptotically optimal in space and time.
An efficient file transmission algorithm for distributed computing systems
(1996)
Chen, DJ
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Chang, PY
;
Lee, YW
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交大名義發表
;
資訊工程學系
In a distributed system, executing a program often requires the access of remote data files. An efficient data transmission strategy is thus important for real-time applications. Since data files may be replicated and their locations are transparent to the executed program, it becomes system's responsibility to select a proper file server such that data can be transmitted in an effective way. In this paper, we consider the scenario that a particular program needs several data files simultaneously for its execution. Each datafile may has replicas across the network. The problem is how to find a collection of file servers and the routing paths such that the data transmission time is minimum. An exhaustive approach could of course find the optimal solution. However if pays for high computation price. We thus proposes a heuristic method. Results obtained from the proposed method are encouraging.
An efficient multipath routing for distributed computing systems with data replication
(1999-11-01)
Chen, DJ
;
Chang, PY
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資訊工程學系
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Department of Computer Science
In distributed computing environments, executing a program often requires the access of remote data files. An efficient data routing scheme is thus important for time-critical applications. To ensure a prior desired communication quality, we present a connection-oriented routing scheme, the multipath routing, which allows multiple routes to be established between the source and the destination. Based on the multipath routing scheme, the problem of finding a collection of routing paths for an application to minimize its data transmission time is addressed. Such a problem becomes a complex combinatorial one when the application accesses multiple replicated data sources. Since finding an optimal solution is computationally infeasible in practice, we thus propose a heuristic method to get a sub-optimal solution. (C) 1999 Elsevier Science Inc. All rights reserved.
Designing lower-dimensional regular arrays for algorithms with uniform dependencies
(1996-02-25)
Tsay, JC
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Chang, PY
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交大名義發表
;
工學院
;
National Chiao Tung University
In this paper, we will propose a polynomial-time method to design m-dimensional regular arrays for n (n greater than or equal to m + 1) dimensional algorithms with uniform dependencies, regular algorithms. The proposed method has two steps: the first one is to transform an independently partitioned regular algorithm to a new one, which has an identity dependence matrix. We call this step identity transformation, which is an affine one. In the second step, we propose a spacetime mapping in a fixed form to map the new regular algorithm to a lower-dimensional regular array. Thus, an affine spacetime mapping is constructed by combining the identity transformation and the fixed form's spacetime mapping together. With the proposed affine spacetime mapping, the original regular algorithm can be mapped to a lower-dimensional regular array in polynomial time, which depends only on the number of dimensions of the regular algorithm. Meanwhile, the designed regular array is asymptotically optimal in time and space. (C) 1996 Academic Press, Inc.
File allocation algorithms to minimize data transmission time in distributed computing systems
(2001-07-01)
Chang, PY
;
Chen, DJ
;
Kavi, KM
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資訊工程學系
;
Department of Computer Science
This work addresses a files allocation problem (FAP) in distributed computing systems. This FAP attempts to minimize the expected data transfer time for a specific program that must access several data files from non-perfect computer sites. We assume that communication capacity can be reserved; hence, the data transmission behavior is modeled as a many-to-one multi-commodity flow problem. A new critical-cut method is proposed to solve this reduced multi-commodity flow problem. Based on this method, two algorithms which use branch-and-bound are proposed for this FAR The proposed algorithms are able to allocate data files having single copies or multiple replicated copies. Simulation results are presented to demonstrate the performance of the algorithms.
Multimedia file allocation on VC networks using multipath routing
(2000-09-01)
Chang, PY
;
Chen, DJ
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Kavi, KM
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資訊工程學系
;
Department of Computer Science
The problem of allocating high-volume multimedia files on a virtual circuit network with the objective of maximizing channel throughput (and minimizing data transmission time) is addressed. The problem is formulated as a multicommodity flow problem. We present both the optimal and suboptimal solutions to the problem using novel approaches.
Optimal routing for distributed computing systems with data replication
(1996)
Chang, PY
;
Chen, DJ
;
資訊工程學系
;
Department of Computer Science