• 제목/요약/키워드: Fuzzy Reasoning System

검색결과 231건 처리시간 0.023초

퍼지집합이론과 사례기반추론을 활용한 채권등급예측모형의 구축 (A Hybrid Approach Using Case-Based Reasoning and Fuzzy Logic for Corporate Bond Rating)

  • 김현정;신경식
    • 지능정보연구
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    • 제10권2호
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    • pp.91-109
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    • 2004
  • 최근 채권의 상환 및 이자의 확실성 정도를 측정하고 연관된 상대적인 위험의 정도를 나타내는 채권등급 평가의 중요성이 대두되고 있다. 초기의 대다수 선행 연구들에서는 기업의 채권 등급예측을 위하여 통계적 기법이 많이 사용되었으나, 많은 연구들에 의해 그 우수성이 보고되고 있는 사례기반 추론 등 인공지능 기법들이 통계모형의 대안으로 제시되어지고 있다. 사례기반 추론에서는 과거의 사례들이 지식으로 표현되고 해결 방법으로 사용된다. 유용한 사례기반 시스템을 구축하기 위해서 시스템의 지식베이스를 구축할 사례들을 인간의 정보처리 과정과 유사한 방법으로 표현하는 것이 중요하다. 본 논문은 실제 세계의 애매모호한 사례들을 다루는데 적절한 퍼지집합개념을 사례기반 추론과 결합하는 통합 방법론을 제시하고자 한다. 퍼지집합이론은 인간이 의사결정시 사용하는 유사한 자연스러운 언어를 수학적으로 변환할 수 있게 해주는 인공지능 기법이다.

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인공신경망을 이용한 퍼지 규칙 인식 시스템 (Fuzzy Rule Identification System using Artifical Neural Networks)

  • 장문석;장덕철
    • 한국정보처리학회논문지
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    • 제2권2호
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    • pp.209-214
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    • 1995
  • 일반적으로 퍼지 시스템 모델링에 있어서, 퍼지 규칙을 인식하고 퍼지 추론의 소속함수를 조정하기란 매우 어렵다.본 논문에서는 인공신경망을 이용함으로써,자동으로 퍼지 규칙을 인식하고 동시에 퍼지 추론의 소속함수를 조정할수 있는 방법을 제시하였다. 본 모델은 역전파를 기본으로 한 알고리즘으로 학습하며,이 방법의 타당성을 로보트 매니퓰레이터를 통해 검증한다.

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학습기능을 사용한 Z. Cao의 퍼지추론방식 (Z. Cao's Fuzzy Reasoning Method using Learning Ability)

  • 박진현;이태환
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2008년도 춘계종합학술대회 A
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    • pp.193-196
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    • 2008
  • 과거 Z. cao는 Relation matrix를 사용한 정밀한 추론이 가능한 NFRM(New fuzzy reasoning method)을 제안하였다. 이는 추론의 규칙 수가 적음에도 불구하고 Mamdani의 퍼지추론방식에 비하여 좋은 성능을 보였다. 그러나 정밀한 추론을 위하여 relation matrix는 시행착오법을 사용하여 구하고, 이는 많은 시간과 노력이 필요하다. 본 연구에서는 이러한 relation matrix를 구하기 위하여 시행착오법에 의해 소요되는 많은 시간과 노력을 줄이고, 더욱 정밀한 추론 성능의 개선을 위하여 경사감소학습법을 사유한 학습기능을 갖는 Z. Cao의 퍼지추론 방식을 제안하고자 한다.

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A Study on Performance Assessment Methods by Using Fuzzy Logic

  • Kim, Kwang-Baek;Kim, Cheol-Ki;Moon, Jung-Wook
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제3권2호
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    • pp.138-145
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    • 2003
  • Performance assessment was introduced to improvement of self-directed learning and method of assessment for differenced learning as the seventh educational curriculum is enforced. Performance assessment is overcoming limitation about problem solving ability and higher thinking abilities assessment that is problem of a written examination and get into the spotlight by way for quality of class and school normalization. But, performance assessment has problems about possibilities of assessment fault by appraisal, fairness, reliability, and validity of grading, ambiguity of grading standard, difficulty about objectivity security etc. This study proposes fuzzy performance assessment system to solve problem of the conventional performance assessment. This paper presented an objective and reliable performance assessment method through fuzzy reasoning, design fuzzy membership function and define fuzzy rule analyzing factor that influence in each sacred ground of performance assessment to account principle subject. Also, performance assessment item divides by formation estimation and subject estimation and designed membership function in proposed performance assessment method. Performance assessment result that is worked through fuzzy performance assessment system can pare down burden about appraisal's fault and provide fair and reliable assessment result through grading that have correct standard and consistency to students.

유전 알고리즘과퍼지 푸론 시스템의 합성 (Fusion of Genetic Algorithms and Fuzzy Inference System)

  • 황희수;오성권;우광방
    • 대한전기학회논문지
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    • 제41권9호
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    • pp.1095-1103
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    • 1992
  • An approach to fuse the fuzzy inference system which is able to deal with imprecise and uncertain information and genetic algorithms which display the excellent robustness in complex optimization problems is presented in this paper. In order to combine genetic algorithms and fuzzy inference engine effectively the new reasoning method is suggested. The efficient identification method of fuzzy rules is proposed through the adjustment of search areas of genetic algorithms. The feasibilty of the proposed approach is evaluated through simulation.

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A Study on the Development of Robust Fault Diagnostic System Based on Neuro-Fuzzy Scheme

  • Kim, Sung-Ho;Lee, S-Sang-Yoon
    • Transactions on Control, Automation and Systems Engineering
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    • 제1권1호
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    • pp.54-61
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    • 1999
  • FCM(Fuzzy Cognitive Map) is proposed for representing causal reasoning. Its structure allows systematic causal reasoning through a forward inference. By using the FCM, authors have proposed FCM-based fault diagnostic algorithm. However, it can offer multiple interpretations for a single fault. In process engineering, as experience accumulated, some form of quantitative process knowledge is available. If this information can be integrated into the FCM-based fault diagnosis, the diagnostic resolution can be further improved. The purpose of this paper is to propose an enhanced FCM-based fault diagnostic scheme. Firstly, the membership function of fuzzy set theory is used to integrate quantitative knowledge into the FCM-based diagnostic scheme. Secondly, modified TAM recall procedure is proposed. Considering that the integration of quantitative knowledge into FCM-based diagnosis requires a great deal of engineering efforts, thirdly, an automated procedure for fusing the quantitative knowledge into FCM-based diagnosis is proposed by utilizing self-learning feature of neural network. Finally, the proposed diagnostic scheme has been tested by simulation on the two-tank system.

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Japanese Speech Based Fuzzy Man-Machine Interface of Manipulators

  • Izumi, Kiyotaka;Watanabe, Keigo;Tamano, Yuya;Kiguchi, Kazuo
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.603-608
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    • 2003
  • Recently, personal robots and home robots are developing by many companies and research groups. It is considered that a general effective interface for user of those robots is speech or voice. In this paper, Japanese speech based man-machine interface system is discussed for reflecting the fuzziness of natural language on robots, by using fuzzy reasoning. The present system consists of the derivation part of action command and the modification part of the derived command. In particular, a unique problem of Japanese is solved by applying the morphological analyzer ChaSen. The proposed system is applied for the motion control of a robot manipulator. It is proved from the experimental results that the proposed system can easily modify the same voice command to the actual different levels of the command, according to the current state of the robot.

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퍼지추론을 적용한 터널 조명제어시스템 (Tunnel Lighting Control System using Fuzzy Reasoning)

  • 이정은;최홍규
    • 전기학회논문지
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    • 제63권8호
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    • pp.1140-1145
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    • 2014
  • Tunnel lighting is composed of entrance zone, interior zone and exit zone by KS C 3703. We have to consider adaptation at entrance zone and exit zone lighting to prevent deteriorate visibility like black hole and white hole phenomenon. So External luminance, vehicle velocity and traffic volume should be considered in threshold zone lighting and vehicle speed and traffic volume should be considered in interior zone lighting. But existing tunnel lighting system is not good at visibility and economic because that is only controled by external luminance. So in this paper, We improve visibility and economic of tunnel lighting system using fuzzy reasoning according to external luminance, vehicle velocity, traffic volume.

A Novel Design of Digital Position Servo System

  • REN H. P.;LIU D.
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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    • pp.380-383
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    • 2001
  • The paper presents a cost effective and increased performance position servo system using the TMS320F240 digital signal processor (DSP) produced by Texas Instruments as microprocessor and Brushless Direct Current Motor (BLDCM) as executor. In order to make up for the drawback of conventional PID controls, the fuzzy PID is employed. The result of simulations and experiments has confirmed that the whole system is simple and reliable; the robustness of system is improved by using fuzzy PID.

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퍼지-뉴럴 네트워크를 이용한 심전도 패턴 분류시스템 설계 (Design of ECG Pattern Classification System Using Fuzzy-Neural Network)

  • 김민수;이승로;서희돈
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 하계종합학술대회 논문집(5)
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    • pp.273-276
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    • 2002
  • This paper has design of ECG pattern classification system using decision of fuzzy IF-THEN rules and neural network. each fuzzy IF-THEN rule in our classification system has antecedent lingustic values and a single consequent class. we use a fuzzy reasoning method based on a single winner rule in the classification phase. this paper in, the MIT/BIH arrhythmia database for the source of input signal is used in order to evaluate the performance of the proposed system. From the simulation results, we can effectively pattern classification by application of learned from neural networks.

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