Browsing by Author "PEARN, WL"

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ALGORITHMS FOR THE CHINESE POSTMAN PROBLEM ON MIXED NETWORKS
(1995-05-01)
PEARN, WL
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LIU, CM
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工業工程與管理學系
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Department of Industrial Engineering and Management
The Chinese postman problem on mixed networks (MCPP), is a practical generalization of the classical Chinese postman problem (CPP), which has many real-world applications. The MCPP has been shown to be NP-complete. Therefore, it is difficult to solve the problem exactly. For this reason, heuristic solution procedures have been proposed to solve the problem approximately. In this paper, we first review two existing solution procedures proposed by Edmonds and Johnson [Math. Progr. 5, 88-124 (1973)], and Frederickson [J. Assoc. Comput. Mach. 26, 538-554 (1979)], then introduce two new algorithms to solve the MCPP near optimally. The proposed new algorithms are tested and compared with the existing solution procedures. Computational results showed that the two new algorithms significantly outperformed the existing solution procedures.
ALGORITHMS FOR THE RURAL POSTMAN PROBLEM
(1995-10-01)
PEARN, WL
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WU, TC
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工業工程與管理學系
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Department of Industrial Engineering and Management
The rural postman problem (RPP) is a practical extension of the well-known Chinese postman problem (CPP), in which a subset of the edges (streets) from the road network are required to be traversed at a minimal cost. The RPP is NP-complete if this subset does not form a weakly connected network. Therefore, it is unlikely that polynomial-time bounded algorithms exist for the problem. In this paper, we review the existing heuristic solution procedures, then present two new algorithms to solve the problem near-optimally. Computational results showed that the proposed new algorithms significantly outperformed the existing solution procedures.
ALGORITHMS FOR THE WINDY POSTMAN PROBLEM
(1994-07-01)
PEARN, WL
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LI, ML
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工業工程與管理學系
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Department of Industrial Engineering and Management
The Windy Postman Problem (WPP), is an interesting generalization of the classical Chinese Postman Problem (CPP), which has many real-world applications. The WPP has been shown to be NP-complete; therefore, it is difficult to solve the problem exactly. For this reason, heuristic solution procedures have been proposed to solve the problem approximately. In this paper, we first review the existing solution procedures, then introduce two new algorithms to solve the WPP near-optimally. Computational results show that the new algorithms outperform the existing solution procedures on some special class of networks.
DISTRIBUTIONAL AND INFERENTIAL PROPERTIES OF PROCESS CAPABILITY INDEXES
(1992-10-01)
PEARN, WL
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KOTZ, S
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JOHNSON, NL
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工業工程與管理學系
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Department of Industrial Engineering and Management
In this paper we survey and critically comment on some basic concepts and notions relevant to the methodology dealing with process capability indices (PCI's). The emphasis is on distributional and inferential aspects. The intent is to contribute to the understanding and interpretation of these indices, if one is (unfortunately) required to use them. We regard them primarily as indicators of the expected proportion of nonconforming items, and not as having some relationship to arbitrary loss functions, as is currently the more fashionable viewpoint. New PCI's, related to the expected proportion of nonconforming items, are suggested.
ESTIMATING PROCESS CAPABILITY INDEXES FOR NONNORMAL PEARSONIAN POPULATIONS
(1995-09-01)
PEARN, WL
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CHEN, KS
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交大名義發表
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工業工程與管理學系
;
National Chiao Tung University
Clements(1) introduced a method for calculating the estimators of two classical process capability indices (PCI), C-p and Cpk, for non-normal Pearsonian populations. Pearn and Kotz(2) applied Clements' method to obtain first approximation estimators of PCIs for non-normal populations to the two more advanced PCIs, C-pm and C-pmk developed by Chan et al.(3) and Pearn ct al.(4) In this paper, we consider a different approach for calculating the estimators of the four PCIs. The new approach may be viewed as a modification of Clements' method. Comparisons between Clements' and the proposed new methods are also provided.
SOLVABLE CASES OF THE K-PERSON CHINESE POSTMAN PROBLEM
(1994-11-01)
PEARN, WL
;
交大名義發表
;
工業工程與管理學系
;
National Chiao Tung University
;
Department of Industrial Engineering and Management
Given a network, the well-known Chinese Postman Problem (CPP) is to find a shortest postman tour traversing each arc of the network at least once and returning to the depot where the postman started. The CPP is NP-complete in general, but is polynomial-time solvable if the network is totally undirected, totally directed, mixed but even, windy with symmetric cycles, and windy but Eulerian. The k-person Chinese Postman Problem (k-CPP) is a multiple-vehicle extension of the CPP, which has many real-world applications. The intent of this paper is to generalize some of the above cited results to the k-CPP.
SOME PROCESS CAPABILITY INDEXES ARE MORE RELIABLE THAN ONE MIGHT THINK
(1993)
KOTZ, S
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PEARN, WL
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JOHNSON, NL
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交大名義發表
;
National Chiao Tung University
In this paper we obtain formulae for exact expected values and standard deviations of estimators of certain process capability indices discussed by Bissell. In particular, we show that for the index C(pk) Bissell's formula gives values for the standard deviation which are too high especially when the actual population mean value is close to (or equal to) the average of the upper and lower specification limits.