Browsing by Author "CHEN, DJ"

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A HEURISTIC ALGORITHM FOR THE RELIABILITY-ORIENTED FILE ASSIGNMENT IN A DISTRIBUTED COMPUTING SYSTEM
(1995-05-01)
CHEN, DJ
;
HOL, WC
;
CHEN, RS
;
CHEN, DTK
;
資訊科學與工程研究所
Distributed Computing Systems (DCS) have become a major trend in today's computer system design because of their high speed and high reliability. Reliability is an important performance parameter in DCS design. Usually, designers add redundant copies of software and/or hardware to increase the system's reliability. Thus, the distribution of data files can affect the program reliability and system reliability. The reliability-oriented file assignment problem is to find a file distribution such that the program reliability or system reliability is maximized. In this paper, we develop a heuristic algorithm for the reliability-oriented file assignment problem (HROFA), which uses a careful reduction method to reduce the problem space. Our numerical results indicate that the HROFA algorithm obtains the exact solution in most cases and the computation time is significantly shorter than that needed for an exact method. When HROFA fails to give an exact solution, the derivation from the exact solution is very small.
A MODELING APPROACH TO THE CONSTRUCTION OF OBJECT-ORIENTED OPERATING-SYSTEMS
(1993-11-01)
LEE, PJ
;
CHEN, DJ
;
KU, KL
;
資訊科學與工程研究所
;
Institute of Computer Science and Engineering
The authors propose an O-O modeling method called, MOOD that provides techniques for modeling the solution-domain objects of an operating system resulting in a set of graphical notations that can be mapped directly into object-oriented programming constructs during the implementation phase. Special attention is paid to reusing existing components and creating reusable components. An example of a ring-driver is given.
A NEW APPROACH TO DESIGN AND IMPLEMENTATION OF IBM PC FOR ACCESSING LIBRARY CD-ROM DATABASE VIA CAMPUS NETWORK
(1993)
CHEN, RS
;
CHEN, DJ
;
YEH, YS
;
資訊科學與工程研究所
;
Institute of Computer Science and Engineering
A NEW HEURISTIC APPROACH FOR RELIABILITY OPTIMIZATION OF DISTRIBUTED COMPUTING SYSTEMS SUBJECT TO CAPACITY CONSTRAINTS
(1995-02-01)
CHEN, RS
;
CHEN, DJ
;
YEH, YS
;
交大名義發表
;
資訊科學與工程研究所
Distributed Computing Systems (DCS) have become a major trend in computer system design today, because of their high speed and reliable performance. Reliability is an important performance parameter in DCS design. In the reliability analysis of a DCS, the term of K-Node Reliability (KNR) is defined as the probability that all nodes in K (a subset of all processing elements) are connected. In this paper, we propose a simple, easily programmed heuristic method for obtaining the optimal design of a DCS in terms of maximizing reliability subject to a capacity constraint. The first part of this paper presents a heuristic algorithm which selects an optimal set of K-nodes that maximizes the KNR in a DCS subject to the capacity constraint. The second part of the paper describes a new approach that uses a K-tree disjoint reduction method to speed up the KNR evaluation. Compared with existing algorithms on various DCS topologies, the proposed algorithm finds a suboptimal design much more efficiently in terms of both execution time and space than an exact and exhaustive method for a large DCS.
A NEW RECURSIVE ALGORITHM FOR THE RELIABILITY EVALUATION OF A DISTRIBUTED PROGRAM
(1992-01-01)
CHEN, DJ
;
SHENG, MC
;
交大名義發表
;
資訊工程學系
;
National Chiao Tung University
The reliability of a distributed program is very sensitive to the ways of file distribution, and communication system topology. It is usually much more complex to analyze the reliability of distributed program than that of the network reliability. This paper presents a distributed program reliability analysis algorithm that is developed based on the concept of sharp operation. The algorithm provides a (E - n + 2) * E memory space requirement and O(n + E + E * N(t)) computation time, where E is the number of edges, n is the number of nodes, and N(t) is the number of file spanning trees in the corresponding graph of distributed system, respectively. Compared with existing algorithms, the proposed algorithm is considered more economic both in time and space.
AN EXPERIMENTAL-STUDY OF USING REUSABLE SOFTWARE-DESIGN FRAMEWORKS TO ACHIEVE SOFTWARE REUSE
(1994-05-01)
CHEN, DJ
;
CHEN, DTK
;
資訊科學與工程研究所
;
Institute of Computer Science and Engineering
AN OBJECT-ORIENTED MODELING APPROACH TO SYSTEM SOFTWARE-DESIGN
(1994-11-01)
LEE, FPJ
;
CHEN, DJ
;
CHUNG, CG
;
資訊科學與工程研究所
;
Institute of Computer Science and Engineering
In this paper, a modelling method entitled MOOD (Modelling approach to Object-Oriented Design) is proposed for the design of object-oriented system software. The method employs entity-refinement, functional modelling, and object modelling techniques to model the world of solution-domain objects. The modelling result based on MOOD forms a set of graphic notations that describe the structure, functions, and client-server relationships among the entities. These graphic notations can be mapped directly into object-oriented programming constructs during the implementation phase. MOOD devotes special attention to the reuse of existing components or newly designed components for future reuse. Unlike other methods, which find objects from textural statements, the entity-refinement approach proposed here can identify all the entities and their operations within the solution domain. MOOD is compared with existing methods to show its feasibility and uniqueness.
DISTRIBUTED PROGRAM RELIABILITY-ANALYSIS
(1992)
LIN, MS
;
CHEN, DJ
;
交大名義發表
;
資訊科學與工程研究所
;
National Chiao Tung University
This paper presents an algorithm for computing the distributed program reliability in Distributed Computing Systems (DCS). The algorithm, called FREA (Fast Reliability Evaluation Algorithm). is based on the generalized factoring theorem with several incorporated reliability-preserving reductions to speedup the reliability evaluation. The effect of file distributions, program distributions, and various topologies on reliability of the DCS is studied in detail using the proposed algorithm. To compute the Distributed Program Reliability, the ARPA network is studied to illustrate the feasibility of the proposed algorithm.
DISTRIBUTED PROGRAM RELIABILITY-ANALYSIS
(1992-01-01)
LIN, MS
;
CHEN, DJ
;
資訊科學與工程研究所
;
Institute of Computer Science and Engineering
This paper presents an algorithm for computing the distributed program reliability in Distributed Computing Systems (DCS). The algorithm, called FREA (Fast Reliability Evaluation Algorithm). is based on the generalized factoring theorem with several incorporated reliability-preserving reductions to speedup the reliability evaluation. The effect of file distributions, program distributions, and various topologies on reliability of the DCS is studied in detail using the proposed algorithm. To compute the Distributed Program Reliability, the ARPA network is studied to illustrate the feasibility of the proposed algorithm.
EFFICIENT ALGORITHMS FOR METHOD DISPATCH IN OBJECT-ORIENTED PROGRAMMING SYSTEMS
(1992-09-01)
HUANG, SK
;
CHEN, DJ
;
資訊科學與工程研究所
;
Institute of Computer Science and Engineering
GENERAL REDUCTION METHODS FOR THE RELIABILITY-ANALYSIS OF DISTRIBUTED COMPUTING SYSTEMS
(1993)
LIN, MS
;
CHEN, DJ
;
交大名義發表
;
資訊科學與工程研究所
;
National Chiao Tung University
The reliability of a distributed computing system is the probability that a distributed program which runs on multiple processing elements and needs to communicate with other processing elements for remote data files will be executed successfully. This reliability varies according to (1) the topology of the distributed computing system, (2) the reliability of the communication links, (3) the data files and program distribution among processing elements, and (4) the data files required to execute a program. This, the problem of analyzing the reliability of a distributed computing system is more complicated than the K-terminal reliability problem, and many of the reliability-preserving reductions for speeding up the computation of the K-terminal reliability cannot be applied to this problem. In this paper, we shall propose several reduction methods for computing the reliability of distributed computing systems. These reduction methods can dramatically reduce the size of a distributed computing system, and therefore speed up the reliability computation.
INTERFACE FOR REUSABLE SOFTWARE COMPONENTS
(1992)
CHEN, DJ
;
HUANG, SK
;
交大名義發表
;
資訊科學與工程研究所
;
National Chiao Tung University
The goal of efficiently reusing software implementation can be reached by solving two fundamental problems. One is how to construct a set of reusable software components and the other is how to provide an environment through which one can easily obtain the desirable components and configure his own software systems. In this paper, we focus on the former problem. trying to survey the difficulties in building flexible software component. One of the predicaments is lying on the problems of interfacing software systems. Those which make software components hard to interface with others are the obstacles to software reuse. In this paper, we identify some interfacing problems, classify types of interface and use notion of interface inheritance and multiple interface to solve these interfacing problems. The proposed strategies include a set of heuristic rules of how to construct a safe and flexible component which can be easily reused. We will constantly emphasize on the importance of interface satisfaction and endeavor to seek a clear view between software server and client, surveying their relationship while interfacing each other.
INTERFACE FOR REUSABLE SOFTWARE COMPONENTS
(1993-01-01)
CHEN, DJ
;
HUANG, SK
;
資訊科學與工程研究所
;
Institute of Computer Science and Engineering
There are two fundamental problems to efficiently reusing software implementations: how to construct a set of reusable software components and how to provide an environment through which one can easily obtain the desirable components to configure one's own systems.
INTERFACE FOR REUSABLE SOFTWARE COMPONENTS
(1992-01-01)
CHEN, DJ
;
HUANG, SK
;
資訊科學與工程研究所
;
Institute of Computer Science and Engineering
The goal of efficiently reusing software implementation can be reached by solving two fundamental problems. One is how to construct a set of reusable software components and the other is how to provide an environment through which one can easily obtain the desirable components and configure his own software systems. In this paper, we focus on the former problem. trying to survey the difficulties in building flexible software component. One of the predicaments is lying on the problems of interfacing software systems. Those which make software components hard to interface with others are the obstacles to software reuse. In this paper, we identify some interfacing problems, classify types of interface and use notion of interface inheritance and multiple interface to solve these interfacing problems. The proposed strategies include a set of heuristic rules of how to construct a safe and flexible component which can be easily reused. We will constantly emphasize on the importance of interface satisfaction and endeavor to seek a clear view between software server and client, surveying their relationship while interfacing each other.
ON DISTRIBUTED COMPUTING SYSTEMS RELIABILITY-ANALYSIS UNDER PROGRAM EXECUTION CONSTRAINTS
(1994-01-01)
CHEN, DJ
;
LIN, MS
;
交大名義發表
;
資訊科學與工程研究所
;
National Chiao Tung University
This correspondence presents an algorithm for computing the reliability of distributed computing systems (DCS). The algorithm, called the Fast Reliability Evaluation Algorithm, is based on the factoring theorem employing several reliability preserving reduction techniques. The effect of file distributions, program distributions, and various topologies on reliability of the DCS is studied in detail using the proposed algorithm. Compared with existing algorithms on various network topologies, file distributions, and program distributions, the proposed algorithm is much more economical in both time and space. To compute the distributed program reliability, the ARPA network is studied to illustrate the feasibility of the proposed algorithm.
ON THE STUDY OF SOFTWARE REUSE USING REUSABLE C++ COMPONENTS
(1993-01-01)
CHEN, DJ
;
LEE, PJ
;
資訊工程學系
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Department of Computer Science
Software reuse has been studied for a long time. To the best of our knowledge, few guidelines and methodologies have been proposed for manufacturing reusable components. Also, not many actual or experimental studies have been conducted to substantiate the quality and productivity improvement of using reusable software components. In this article, we present a way (based on object interface) to manufacture reusable software components and propose a software construction method with guidelines for using designed reusable C++ components. Currently, we have developed about 130 reusable C++ components and have classified them into a manageable structure. We conducted a controlled experiment to substantiate the proposed software reuse approach in terms of software productivity and quality. Compared with the traditional design and implementation approach, the proposed construction approach demonstrates its advantages for both software productivity and software quality improvement. These advantages are evident from the software metrics generated in the experiment.
PARALLEL ROUTING ALGORITHMS FOR INCOMPLETE HYPERCUBE INTERCONNECTION NETWORKS
(1994-12-01)
HORNG, MS
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CHEN, DJ
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KU, KL
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資訊科學與工程研究所
;
Institute of Computer Science and Engineering
Hypercube interconnection networks have been receiving considerable attention in the supercomputing environment. However, the number of processors must be exactly 2r for an r-cube complete hypercube. This restriction severely limits its applicability. In this paper, we address three variant hypercube topologies with more flexibility in system sizes, the labelled hypercubes I(m)r, I(M)r, and I(A)r. Incomplete hypercube I(m)r consists of an r-cube and an m-cube complete hypercubes; I(m)r is composed of 2r and SIGMA(m) is-an-element of M2m nodes; I(Ar) comes from an r-cube complete hypercube which operates in a degraded manner and allows that the missing nodes to be arbitrarily distributed. Specifically, we focus on the parallel paths routing algorithms for these three classes of incomplete hypercubes. Parallel paths between any given two nodes mean that these paths have the same source and destination nodes but with different intermediate nodes. Parallel communication is important as it will allow us to use the full bandwidth of the multiprocessors for the data transfer operation between any two nodes, and these redundant paths can increase system fault-tolerance and communication reliability. With these parallel routing algorithms, one can use them as a criterion to design multiprocessor systems.
RELIABILITY OPTIMIZATION OF DISTRIBUTED COMPUTING SYSTEMS SUBJECT TO CAPACITY CONSTRAINTS
(1995-02-01)
CHEN, RS
;
CHEN, DJ
;
YEH, YS
;
交大名義發表
;
資訊科學與工程研究所
In this paper, we propose a simple, easily programmed exact method for obtaining the optimal design of a distributed computing system in terms of maximizing reliability subject to memory capacity constraints. We assume that a given amount of resources are available for linking the distributed computing system. The method is based on the partial order relation. To speed up the procedure, some rules are proposed to indicate conditions under which certain vectors in the numerical ordering that do not satisfy the capacity constraints can be skipped over. Simulation results show that the proposed algorithm requires less time and space than exhaustive method.
RELIABILITY-ANALYSIS OF DISTRIBUTED SYSTEMS BASED ON A FAST RELIABILITY ALGORITHM
(1992-03-01)
CHEN, DJ
;
HUANG, TH
;
交大名義發表
;
資訊工程學系
;
National Chiao Tung University
The reliability of distributed processing system (DPS) can be expressed by the analysis of distributed program reliability (DPR) and distributed system reliability (DSR). One of the good approaches to formulate these reliability performance indexes is to generate all disjoint File Spanning Trees (FST's) in the DPS graph such that the DPR and DSR can be expressed by the probability that at least one of these FST's is working. In this paper, we present a unified algorithm to efficiently generate disjoint FST's by cutting different links and compute the DPR and DSR based on a simple and consistent union operation on the probability space of the FST's. The DPS reliability related problems are also discussed in this paper. These include 1) the reliability of more than one copy of programs running on a given DPS starting from different sites, 2) the reliability of a specified program running on a given DPS starting from different sites, 3) the reliability of more than one different programs running on a given DPS, and so on. For speeding up the reliability evaluation, nodes merged, series, and parallel reduction concepts are incorporated in the algorithm. Based on the comparison of number of subgraphs (or FST's) generated by the proposed algorithm and by existing evaluation algorithms, we conclude that the proposed algorithm is much more economic in terms of time and space than the existing algorithms.
REQUIREMENTS ORGANIZATION APPROACH FOR OBJECT-BASED CONSTRUCTION OF SOFTWARE SYSTEMS
(1992-07-01)
CHEN, DJ
;
LEE, PJ
;
HUANG, SK
;
交大名義發表
;
資訊工程學系
The paper discusses a requirements organization approach for the object-oriented design of software systems. Specifically, the requirements organization approach is developed based on a requirements clustering approach. The requirements organization approach can outline the constructed software system in the object-oriented paradigm, provide guidelines for system construction, receive early feedback from the different parties involved, allow the modification of inconsistent requirements, and design inexpensively the software system using an object-based programming language. An example is provided to illustrate the object-oriented design of software systems using the proposed requirements organization approach. Assessment and experiments are conducted to substantiate the benefits of the requirements organization approach.