• Title/Summary/Keyword: Fuzzy Logic System

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A Construction of Fuzzy Inference Network based on Neural Logic Network and its Search Strategy

  • Lee, Mal-rey
    • 한국산업정보학회:학술대회논문집
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    • 한국산업정보학회 2000년도 추계공동학술대회논문집
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    • pp.375-389
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    • 2000
  • Fuzzy logic ignores some information in the reasoning process. Neural networks are powerful tools for the pattern processing, but, not appropriate for the logical reasoning. To model human knowledge, besides pattern processing capability, the logical reasoning capability is equally important. Another new neural network called neural logic network is able to do the logical reasoning. Because the fuzzy inference is a fuzzy logical reasoning, we construct fuzzy inference network based on the neural logic network, extending the existing rule- inference. network. And the traditional propagation rule is modified. For the search strategies to find out the belief value of a conclusion in the fuzzy inference network, we conduct a simulation to evaluate the search costs for searching sequentially and searching by means of search priorities.

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퍼지 추론에 의한 한열 판별 (Distinction of Hot-Cold Using Fuzzy Inference)

  • 장윤지;김영은;김철;송미영;이은주
    • 대한한의진단학회지
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    • 제19권3호
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    • pp.141-149
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    • 2015
  • Objectives Recently the fuzzy logic is widely used in the decision making, identification, pattern recognition, optimization in various fields. In this study, we propose the fuzzy logic as the objective method of distinguishing hot and cold, the basis of diagnosis in Korean medicine. Methods We developed fuzzy inference system to distinguish whether the subjects had hot or cold. The cold and hot questionnaire of Korean traditional university textbook, the pulse rate and the DITI value of face used in the system. These three kinds of information were defined as 'fuzzy sets,' and 54 fuzzy rules were established on the basis of clinical practitioners' knowledge. The fuzzy inference was performed by using the Mamdani's method. To evaluate the usefulness of the fuzzy inference system, 200 cases of data measured in the Woosuk university hospital of oriental medicine were used to compare the determining hot, normal, cold results obtained from the experts and from the proposed system. Results As a result, 100 cases of "cold", 54 cases of "normal", and 34 cases of "hot" were matched between the experts and the proposed system. This fuzzy system showed the conformity degree of 94%(${\kappa}=0.853$). Conclusions In this study, we could express the process of distinguishing hot-cold using the fuzzy logic for objectification and quantification of hot-cold identification. This is the first study that introduce a fuzzy logic for distinguish pattern identification. The degree of the heat characteristic of the patients inferred by this system could provide a more objective basis for diagnosing the hot-cold of patients.

T-operators를 이용한 Fuzzy Control System의 설계 및 응용 (The Design and application of Fuzzy control System using T-operators)

  • 김일;이상배
    • 한국항해학회지
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    • 제20권1호
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    • pp.87-96
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    • 1996
  • In this paper, The Fuzzy Logic Controller based on T-operators is designed. Some typical T-operators and their mathematical properties are studied. A generalized fuzzy inference model is proposed by introducing the general notion of T-operators into the conventional one which is based only on the Min and Max operators. Fuzzy Logic Control algorithms based on the T-operators are suggested. Then, by computer simulations, the effect of various T-operators on the performance of the fuzzy logic controller are studied. The purpose of these simulation studies were to observe the flexibility and system responses using the processed class of T-operators in the fuzzy inference mechanisms. This observation was made on parameters such as speed of reponses, steady-state behavior and non oscillatory responses.

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퍼지논리를 사용한 엔진 동력계 시스템의 트로틀 밸브 제어기 설계 및 구현 (Design and implementation of a throttle valve controller for engine dynamometer systems using fuzzy logic)

  • 신위재;이상윤
    • 제어로봇시스템학회논문지
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    • 제3권6호
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    • pp.588-593
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    • 1997
  • This paper shows a design and implementation of throttle valve controller for engine dynamometer system using fuzzy logic. Recently, we demanded the excellent measuring equipment so as to improve engine performance. The throttle valve control for engine dynamometer system is a very particular part in the engine control. Since the structure of engine dynamometer system is very complicated and has nonlinear elements which are influenced by disturbance of vibration, heating, cooling, and energy loss so on. In this paper, fuzzy logic control application have been successful in throttle valve control problem for engine dynamometer system in which the conventional control had difficulties dealing with the system. In this study, we propose a method that the control strategy uses Fuzzy Look-up table and normalization and obtained the satisfying result from realized throttle valve controller for engine dynamometer system.

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Fuzzy Logic Modifier를 가진 Pl 제어기에 의한 스위치드 리럭턴스 전동기의 속도제어 (Speed Control of SRM by Pl Controller with Fuzzy Logic Modifier)

  • 김보형;김재문;원충연
    • 전기전자학회논문지
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    • 제2권2호
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    • pp.299-308
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    • 1998
  • 본 논문에서는 신뢰할 수 있는 SRM 구동시스템과 기존의 PI제어기에 4개의 규칙으로 이루어진 FLM(Fuzzy Logic Modifier)를 제안하였다. 저가격 원칩 마이크로컨트롤러인 인텔사의 i80C196KC는 속도 제어기와 초기 기동을 포함한 SRM 구동 컨트롤러를 설계하기 위해 사용되었다. 폐루프 시스템에 안정된 효과를 보이는 FLM을 Pl 제어기에 추가함으로써 부적절하게 설정된 PI 제어기의 이득값에 대해 강인한 제어성능을 보인다. 시뮬레이션 및 실험결과는 6/4극 SRM에 대해 제안된 제어 방식이 우수함을 보여준다.

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퍼지논리에 의한 후방주차 시스템 설계 (Design of Backward Parking System using Fuzzy Logic)

  • 학양화;김태균;최병재;류석환
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2007년도 춘계학술대회 학술발표 논문집 제17권 제1호
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    • pp.337-340
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    • 2007
  • 무인자동차에 관한 연구가 활성화되면서 무인 주차 또한 중요한 과제로 대두되고 있다. 본 논문에서는 무인 차량을 위한 주차 편의 시스템 설계를 위하여 퍼지논리시스템에 의한 주차 알고리즘을 설계하고자 한다. 기존의 논문들이 제시한 장단점을 분석하여 새로운 단순 구조 형태의 규칙표를 통한 주차 알고리즘을 설계, 구현하고, 시뮬레이션을 통하여 그 효용성을 확인하고자 한다.

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퍼지논리를 이용한 유도전동기의 속도제어기 설계 (A Design of Speed Controller for Induction Motor using Fuzzy Logic)

  • 임영철;나석환;위석호;양형렬;안정훈
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1998년도 추계학술대회 학술발표 논문집
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    • pp.244-249
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    • 1998
  • Abstract-A speed controller of a induction motor using Microcontroller and Fuzzy logic is presented in the paper. Generally fuzzy logic controller is known as a controller which 춤 be coped with a non-linear and a complex system. A fuzzy logic is used for robust and fast speed control and space vector modulation method is used for PWM wave generation in this proposed system. The results of experiment show excellence of the proposed system and that the proposed system is appropriate to control the speed of a induction motor for industrial application

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피부전기 활동과 fuzzy추론에 의한 각성도의 평가 (Evaluation of arousal level by EDA and fuzzy inference)

  • 김연호;고한우;유준
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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    • pp.1856-1859
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    • 1997
  • This paper describes the arousal measurement and the control system using fuzzy logic to prevent drowsy driving. Sugeno's method was used for fuzzy inference in this study. Membership function and rule base were determined form the modfied arousal level criteria. The output of fuzzy inference tracked well the change of subject's arousal level. When IRI(Inter-SIR interval) was under the 60sec, maximum output of three step warning method was medium sound, but that of fuzzy logic system was changed from medium to big. Furthermore, the output of the fuzzy inference was highly correlated with $N_{z}$(r=0.99). Therefore, the fuzzy inference method for evaluation and the control of arousal will be more effective at real driving sityation than three step warning method.ning method.

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$\alpha$-레벨 퍼지집합 분해에 의한 직류 서보제어용 퍼지 PI+PD 로직회로 구현 (Implemented of Fuzzy PI+PD Logic circuits for DC Servo Control Using Decomposition of $\alpha$-level fuzzy set)

  • 홍정표;원태현;정종원;이영수;이상무;홍순일
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2008년도 하계학술대회 논문집
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    • pp.127-129
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    • 2008
  • This paper describes a method of approximate reasoning for fuzzy control of servo system, based on decomposition of -level fuzzy sets. It is propose that logic circuits for fuzzy PI+PD are a body from fuzzy inference to defuzzificaion in cases where the output variable u directly is generated PWM. The effectiveness for robust and faster response of the fuzzy control scheme is verified for a variable parameter by comparison with a PID control and fuzzy control. A position control of DC servo system with a fuzzy logic controller successfully demonstrated.

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PMSM 드라이브의 고성능 속도제어를 위한 적응 퍼지제어기 (Adaptive Fuzzy Control for High Performance Speed Controller in PMSM Drive)

  • 정동화;이정철;이홍균;정택기
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.79-81
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    • 2002
  • This paper develops a adaptive fuzzy controller based fuzzy logic control for high performance speed controller in permanent magnet synchronous motor(PMSM) drives. In the proposed system, fuzzy control is used to implement the direct controller as well as the adaptation mechanism. The operation of the direct fuzzy controller and the fuzzy logic based adaptation mechanism is studied. A model reference adaptive scheme is proposed in which the adaptation mechanism is executed by fuzzy logic based on the error and change of error measured between the motor speed and output of a reference model. The control performance of the adaptive fuzzy controller is evaluated by simulation for various operating conditions. The validity of the proposed adaptive fuzzy controller is confirmed by performance results for PMSM drive system.

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