Browsing by Author "CHEN, SM"

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A COMPARISON OF SIMILARITY MEASURES OF FUZZY VALUES
(1995-05-26)
CHEN, SM
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YEH, MS
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HSIAO, PY
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交大名義發表
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資訊工程學系
This paper extends the work of Pappis and Karacapilidis (1993) to present and compare the properties of several measures of similarity of fuzzy values. The measures examined in this paper are based on the geometric model, the set-theoretic approach, and the matching function S we presented in (Chen, 1988). It is shown that several properties are common to all measures and some properties do not hold for all of them.
A KNOWLEDGE ACQUISITION SCHEME FOR RULE-BASED SYSTEMS
(1993)
CHEN, SM
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資訊工程學系
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Department of Computer Science
A NEW APPROACH TO INEXACT REASONING FOR RULE-BASED SYSTEMS
(1992-11-01)
CHEN, SM
;
交大名義發表
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資訊工程學系
;
National Chiao Tung University
;
Department of Computer Science
This paper presents a new algorithm for dealing with inexact reasoning problems, where the certainty factors of the rules and the truth values of the conditions appearing in the rules are represented by linguistic terms. The algorithm performs inexact reasoning via repeatedly transforming an augmented linguistic truth state vector T by an augmented linguistic rule matrix F. Given the linguistic truth values of some conditions, the algorithm can perform inexact reasoning to evaluate the linguistic truth values of other conditions automatically.
A NEW METHOD FOR HANDLING MULTICRITERIA FUZZY DECISION-MAKING PROBLEMS
(1994-05-01)
CHEN, SM
;
交大名義發表
;
資訊工程學系
;
National Chiao Tung University
;
Department of Computer Science
This paper presents a new method for handling multicriteria fuzzy decision-making problems, in which the characteristics of the alternatives are represented by interval-valued fuzzy sets, and some techniques are developed to calculate the degree of similarity between interval-valued fuzzy sets. The proposed method is more flexible than the one we presented earlier (Chen et al., 1989) because it allows the criteria values of the alternatives to be represented by real intervals rather than crisp real values between zero and one.
A NEW METHODOLOGY FOR FUZZY CONTROL-BASED ON WEIGHTED FUZZY LOGICS
(1993)
CHEN, SM
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資訊工程學系
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Department of Computer Science
A QUANTITATIVE STUDY OF THE FAR-FIELD LASER-INDUCED RING PATTERN FROM NEMATIC LIQUID-CRYSTAL FILMS
(1992-08-01)
PAN, RP
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CHEN, SM
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PAN, CL
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電子物理學系
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光電工程學系
We report the first detailed measurement of multiple (up to twenty) diffraction rings due to a laser beam traversing a nematic liquid crystal cell. Experimental measured intensity distributions are in good agreements with numerical calculations based on the diffraction theory, taking into account the spatial self-phase modulation effect, the two-dimensionality of the problem, the wavefront curvature effect and the non-local response of the nematic liquid crystals. The individual contributions of the aforementioned effects on the far-field pattern are clearly illustrated.
A WEIGHTED FUZZY-REASONING ALGORITHM FOR MEDICAL DIAGNOSIS
(1994-01-01)
CHEN, SM
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交大名義發表
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資訊工程學系
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National Chiao Tung University
;
Department of Computer Science
This paper presents a weighted fuzzy reasoning algorithm for handling medical diagnostic problems, where fuzzy set theory and fuzzy production rules are used for knowledge representation. The algorithm can perform fuzzy matching between the patient's symptom manifestations and the antecedent portions of fuzzy production rules to determine the presence of diseases, where the result is interpreted as a certainty level indicating the degree of certainty of the presence of the disease. Because the algorithm allows each symptom in medical diagnosis to have a different degree of importance, it is more flexible than the ones we presented in [3] and [4]. The algorithm can be executed very efficiently. If the knowledge base contains n fuzzy production rules and there are p symptoms, then the time complexity of the algorithm is O(np).
AN IMPROVED ALGORITHM FOR INEXACT REASONING BASED ON EXTENDED FUZZY PRODUCTION RULES
(1992-09-01)
CHEN, SM
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交大名義發表
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資訊工程學系
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National Chiao Tung University
;
Department of Computer Science
This paper proposes a new algorithm to deal with inexact reasoning, where extended fuzzy production rules are used for knowledge representation. Given the truth values of some conditions, the algorithm can perform inexact reasoning to evaluate the truth values of other conditions efficiently and automatically. First, the extended fuzzy production rules in a knowledge base are modeled by an augmented fuzzy rule matrix F. Then, based on the transitive closure of the augmented fuzzy rule matrix F, we develop an efficient algorithm for inexact reasoning. The algorithm proposed in this paper is better than the one presented in Chen et al. (1991) because it can handle the case of circular rules and can be executed more efficiently.
ANALYSIS OF BEAM SIZE EFFECT ON THE LASER-INDUCED FREEDERICKSZ TRANSITION AND THE DYNAMIC-RESPONSE IN NEMATIC LIQUID-CRYSTAL (5CB) FILMS WITH A FREE-SURFACE
(1992-02-01)
CHEN, SM
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PAN, RP
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電子物理學系
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光電工程學系
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Department of Electrophysics
The non-local effect caused by the finite laser beam size in the laser induced Freedericksz transition for the homeotropically aligned nematic liquid crystal film is derived analytically and calculated numerically. The influences on the transition threshold and the dynamic response are discussed. The coupling between backflow effect and the non-local effect is shown to be important for the films with a free surface by the calculated results and by comparing with the existing experimental results.
COGNITIVE-MAP-BASED DECISION-ANALYSIS BASED ON NPN LOGICS
(1995-04-28)
CHEN, SM
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交大名義發表
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資訊工程學系
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National Chiao Tung University
;
Department of Computer Science
This paper presents a new method for cognitive-map-based decision analysis based on negative-positive-neutral (NPN) logics, where an efficient algorithm is proposed for performing interval-based inexact reasoning automatically. The algorithm performs inexact reasoning via constructing a sprouting tree. The time complexity of the proposed algorithm is O(nm), where n is the number of cognitive units in the cognitive map, m is the length of a closure path, and max(m) = 2n.
DOCUMENT-RETRIEVAL USING KNOWLEDGE-BASED FUZZY INFORMATION-RETRIEVAL TECHNIQUES
(1995-05-01)
CHEN, SM
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WANG, JY
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資訊工程學系
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Department of Computer Science
A knowledge-based approach for fuzzy information retrieval is proposed, where interval queries and weighted-interval queries are allowed for document retrieval, In this paper, knowledge is represented by a concept matrix, where the elements in a concept matrix represent relevant values between concepts, The implicit relevant values between concepts are inferred by the transitive closure of the concept matrix based on fuzzy logic. The proposed method is more flexible than the ones presented in [6] and [11] due to the fact that it has the capability to deal with interval queries and weighted-interval queries.
DOCUMENT-RETRIEVAL USING KNOWLEDGE-BASED FUZZY INFORMATION-RETRIEVAL TECHNIQUES
(1995-05-01)
CHEN, SM
;
WANG, JY
;
交大名義發表
;
資訊工程學系
;
National Chiao Tung University
A knowledge-based approach for fuzzy information retrieval is proposed, where interval queries and weighted-interval queries are allowed for document retrieval, In this paper, knowledge is represented by a concept matrix, where the elements in a concept matrix represent relevant values between concepts, The implicit relevant values between concepts are inferred by the transitive closure of the concept matrix based on fuzzy logic. The proposed method is more flexible than the ones presented in [6] and [11] due to the fact that it has the capability to deal with interval queries and weighted-interval queries.
FREE-SURFACE EFFECTS ON THE RESPONSE OF NEMATIC LIQUID-CRYSTAL FILMS TO A LASER-PULSE
(1993-05-01)
PAN, RP
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CHEN, SM
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YANG, HY
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電子物理學系
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光電工程學系
The dynamic response of 5CB films with a free surface to a laser pulse is investigated. A magnetic field above the Freedericksz transition is applied initially to induce a starting angle on the molecular orientation. A single 1.06 mum laser pulse with e-1 pulse width 0.2 ms is incident normally upon the films. When the laser pulse polarization is perpendicular to the magnetic field, only a thermal effect is involved. While it is parallel to the magnetic field, both molecular orientation and thermal effects are involved. The results from films with a free surface are compared with those from films sandwiched between two glass substrates. The free surface effect, beam size effect, and thermal effect are discussed by comparing with theoretical analysis.
FUZZY SYSTEM RELIABILITY-ANALYSIS USING FUZZY NUMBER ARITHMETIC OPERATIONS
(1994-05-25)
CHEN, SM
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交大名義發表
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資訊工程學系
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National Chiao Tung University
;
Department of Computer Science
This paper presents a new method to analyze fuzzy system reliability using fuzzy number arithmetic operations, where the reliability of each system component is represented by a triangular fuzzy number. Because the proposed method uses simplified fuzzy arithmetic operations of fuzzy numbers rather than the complicated interval arithmetic operations of fuzzy numbers mentioned by Cheng and Mon in Fuzzy Sets and Systems 56 (1993) 29-35 or the complicated extended algebraic operations of fuzzy numbers mentioned by Singer in Fuzzy Sets and Systems 34 (1990) 145-155, its execution is faster than the ones presented by Cheng and Mon, and Singer.
FUZZY SYSTEM RELIABILITY-ANALYSIS USING FUZZY NUMBER ARITHMETIC OPERATIONS (VOL 64, PG 31, 1994)
(1995-01-27)
CHEN, SM
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交大名義發表
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資訊工程學系
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National Chiao Tung University
;
Department of Computer Science
HANDLING MULTICRITERIA FUZZY DECISION-MAKING PROBLEMS BASED ON VAGUE SET-THEORY
(1994-10-24)
CHEN, SM
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TAN, JM
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交大名義發表
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資訊工程學系
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National Chiao Tung University
New techniques for handling multicriteria fuzzy decision-making problems based on vague set theory are presented. The proposed techniques allow the degrees of satisfiability and non-satisfiability of each alternative with respect to a set of criteria to be represented by vague values. Furthermore, the proposed techniques allow the decision-maker to assign a different degree of importance to each criteria. The techniques proposed in this paper can provide a useful way to efficiently help the decision-maker to make his decisions.
IDENTIFICATION OF 3RD-ORDER AND 5TH-ORDER SELF-PHASE MODULATION EFFECTS IN LASER-INDUCED DIFFRACTION RINGS FROM A NEMATIC LIQUID-CRYSTAL FILM
(1990-11-15)
CHEN, SM
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PAN, RP
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PAN, CL
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交大名義發表
;
光電工程學系
INTERFEROMETRIC MEASUREMENTS OF THE THICKNESS OF NEMATIC LIQUID-CRYSTAL FILMS WITH A FREE-SURFACE
(1989-12-01)
CHEN, SM
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PAN, RP
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PAN, CL
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交大名義發表
;
電子物理學系
MAGNETIC-FIELD-INDUCED FREEDERICKSZ TRANSITION AND THE DYNAMIC-RESPONSE OF NEMATIC LIQUID-CRYSTAL FILMS WITH A FREE-SURFACE
(1991-03-15)
CHEN, SM
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HSIEH, TC
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PAN, RP
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電子物理學系
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光電工程研究所
The Freedericksz transition and the dynamic response of homeotropical liquid-crystal films with a free surface (FS) induced by a perpendicular dc magnetic field have been studied theoretically and experimentally for two nematic substances: 4'-n-pentyl-4-cyanobiphenyl (5CB) and 4'-n-octyl-4-cyanobiphenyl (8CB). For either one of these two materials, it is found that the critical magnetic field of these two nematic liquid-crystal (NLC) films with a free surface is equal to that of the NLC film with hard boundaries (HB) of the same thickness. This thus demonstrates a very strong orientational anchoring for 5CB and 8CB at the free surface. The intrinsic structures of FS samples are homeotropic, just as the HB ones are. For the dynamic response, the turn-off rates of FS samples are found to be about two times faster than those of the HB ones. This is interpreted with the backflow theory and the lack of positional anchoring on the free surface. Finally, a sensitive approach to determine the viscosity coefficients, gamma-1 and eta-c, of the NLC film is suggested.
MEASURES OF SIMILARITY BETWEEN VAGUE SETS
(1995-09-15)
CHEN, SM
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交大名義發表
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資訊工程學系
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National Chiao Tung University
;
Department of Computer Science
In this paper, we propose two similarity measures for measuring the degree of similarity between vague sets. The proposed measures can provide a useful way for measuring the degree of similarity between vague sets.