• Title/Summary/Keyword: Fuzzy Expert Systems

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Fuzzy Traffic Control Expert System (퍼지 교통 제어 전문가 시스템)

  • 진정애;김용기
    • Journal of Intelligence and Information Systems
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    • v.1 no.2
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    • pp.17-32
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    • 1995
  • 본 논문에서는 추론엔진 (inference engine)내에 퍼지정보 검색부(Fuzzy Information Retrieval part)를 갖는 교통신도 제어 전문가 시스템을 제안한다. 제안하는시스템은 다양하고 복잡한 도로 상화을 고려하여 그에 따른 적절한 주기를 각 도로별로 할당함으로써 원활한 교통 흐름을 제어한다. 추론엔진내의 퍼지정보 검색부는 퍼지 삼각 논리곱을 이용하여 도로의 상황을 분석한 후 각 도로에 맞는 가장 적절한 신호주기를 생성한다.

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Fuzzy based Intelligent Expert Search for Knowledge Management Systems

  • Yang, Kun-Woo;Huh, Soon-Young
    • Journal of Intelligence and Information Systems
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    • v.9 no.2
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    • pp.87-100
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    • 2003
  • In managing organizational tacit knowledge, recent researches have shown that it is more applicable in many ways to provide expert search mechanisms in KMS to pinpoint experts in the organizations with searched expertise. In this paper, we propose an intelligent expert search framework to provide search capabilities for experts in similar or related fields according to the user′s information needs. In enabling intelligent expert searches, Fuzzy Abstraction Hierarchy (FAH) framework has been adopted, through which finding experts with similar or related expertise is possible according to the subject field hierarchy defined in the system. To improve FAH, a text categorization approach called Vector Space Model is utilized. To test applicability and practicality of the proposed framework, the prototype system, "Knowledge Portal for Researchers in Science and Technology" sponsored by the Ministry of Science and Technology (MOST) of Korea, was developed.

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Operation of a supercritical fluid extraction process using a fuzzy expert control system (Fuzzy 전문가 제어계를 이용한 초임계 유체 추출 장치의 운전)

  • 이대욱;이광순
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10a
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    • pp.669-675
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    • 1991
  • Based on process analysis as well as extensive operation experience, two fuzzy expert control algorithms, for startup and control, are proposed for a supercritical fluid extraction process which has high interacting multivariable structure. In the proposed algorithms, a new simple defuzzification method which only requires four fundamental arithmetic rules is also presented. Through numerical simulations, control performance using the proposed control algorithm is compared with that of a different fuzzy algorithm by an other researcher and that of conventional PID-type controllers which are tuned by well-known optimal criteria. Also, the proposed control algorithm has been tested to the bench scale supercritical fluid extraction process. As a consequence, the proposed fuzzy expert controller has shown fast and robust control performance while the other controllers show sluggish and/or highly oscillatory responses.

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Fuzzy Inference Engine for Ontology-based Expert Systems (온톨로지 기반의 전문가 시스템 구축을 위한 퍼지 추론 엔진)

  • Choi, Sang-Kyoon;Kim, Jae-Saeng
    • The Journal of the Korea Contents Association
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    • v.9 no.6
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    • pp.45-52
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    • 2009
  • Recently, we started a project development of the digital expert system for the product design supporting in manufacturing industry. This digital expert system is used to the engineers in manufacturing industry for the process control, production management and system management. In this paper, we develop the ontology based inference engine shell for building of expert system. This expert system shell included a various functions which of Korean language supporting, graphical ontology map modeling interface, fuzzy rule definition function and etc. And, we introduce the knowledge representation method for the ontology map building and ontology based fuzzy inferencing method.

Fault Evaluation Based on Fuzzy Logic for Analog Electronic Circuits

  • Hashizume, Masaki;Iwata, Yoshihiro;Tamesada, Takeomi
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1993.06a
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    • pp.1402-1405
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    • 1993
  • In this paper, a fault evaluation method is proposed, which is to determine whether analog electronic circuits are faulty or not. In our method, evaluation characteristics of an expert test engineer are defined by means of directed graphs. By performing a multi-stage fuzzy inference based on the graphs, novice test engineers can derive a fault evaluation result satisfied by the expert. The effectiveness of our method is checked by some experiments for an amplifier circuit.

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A Study on the Optimal Design of Fuzzy Logic Controller (퍼지제어기의 최적 설계에 관한 연구)

  • 노기갑;김성호;주영훈;박진배
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1997.10a
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    • pp.50-54
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    • 1997
  • In general, the design of fuzzy logic controller has difficulties in the acquisition of expert's knowledge. So, some methods that can optimize the parameters for fuzzy logic controller automatically without expert knowledge was provided. Recently, tuning method for fuzzy logic controller using genetic algorithm(GA) were proposed in many papers. However, those are tuning methods for a part or some part of fuzzy logic controller. In this paper, we proposes auto tuning method for the whole part of tuzzy logic controller, such as parameters of membership functions for antecedence and consequence parts, rule base, scaling factor and the number of rule. Finally, second order dead time plant is provided to show the advantages of the proposed method.

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Development of controller for anti-swing and position of crane (크레인의 Anti-Swing 및 위치 제어기의 개발)

  • 정승현;권판조;이달해
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.277-281
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    • 1996
  • The roof crane system is used for transporting a variable load to a target position. At this time, the goal of crane system is transporting to a goal position as soon as possible with no rope oscillation. Generally crane is operated by expert's knowledge, but recently automatic control with high speed and rapid transportation is required. In this thesis we developed fuzzy controller of crane which has simplified expert's knowledge base for anti-swing and rapid tansportation to goal position.

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Power System Fault Diagnosis using Possibility Theory (가능성 이론을 이용한 전력계통 고장진단)

  • Lee, Heung-Jae;Lee, Chul-Kyun;Park, Deung-Yong;Kim, Seong-Hee;Ahn, Bok-Shin
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.6
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    • pp.665-670
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    • 1999
  • This paper introduces a fuzzy expert systems for fault diagnosis, where the causal relationships between faults and protective devices are defined as fuzzy relations. The uncertainties existing in the fault diagnosis are figured out using the possibility theory and the possibility measure is associated with the fuzzy relation to evaluate the possibilities of faults. Besides, the knowledge base in the expert system is described and explained. In this way, multiple-fault can be handled easily and simultaneously together with single faults.

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Fuzzy Belief Network : Approximate Reasoning System Using The Possiblity (Fuzzy Belief Network : 가능성을 이용한 근사추론 시스템)

  • 조상엽;김기태
    • Korean Journal of Cognitive Science
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    • v.4 no.1
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    • pp.261-294
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    • 1993
  • Most of expert systems,as a rule-based system,should be convenient to modify a rule and to insert a new rule, which is called modularity of rules. When we think correlated evidences in expert systems. conventional systems are too local to recognize the common origin of the information, and they would update the belief of the hypothesis as if it were supposed by independence soureces. In this paper to overcome such drawbacks we propose Fuzzy Belief Network which is based on the Beysian Network which provide the modulartiy between rules. To build Fuzzy Belief Network, we define nodes and links and propose algorithms for data fusion in individual node and for propagation belief value obtained as a result of data fusion.

Fuzzy Inference of Large Volumes in Parallel Computing Environment (병렬컴퓨팅 환경에서의 대용량 퍼지 추론)

  • 김진일;박찬량;이동철;이상구
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2000.05a
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    • pp.13-16
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    • 2000
  • In fuzzy expert systems or database systems that have huge volumes of fuzzy data or large fuzzy rules, the inference time is much increased. Therefore, a high performance parallel fuzzy computing environment is needed. In this paper, we propose a parallel fuzzy inference mechanism in parallel computing environment. In this, fuzzy rules are distributed and executed simultaneously. The ONE_TO_ALL algorithm is used to broadcast the fuzzy input vector to the all nodes. The results of the MIN/MAX operations are transferred to the output processor by the ALL_TO_ONE algorithm. By parallel processing of fuzzy rules or data, the parallel fuzzy inference algorithm extracts effective parallel ism and achieves a good speed factor.

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