• 제목/요약/키워드: Fuzzy Functions

검색결과 944건 처리시간 0.028초

개별 입력 공간에 의한 퍼지 추론 시스템의 비선형 특성 (Nonlinear Characteristics of Fuzzy Inference Systems by Means of Individual Input Space)

  • 박건준;이동윤
    • 한국산학기술학회논문지
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    • 제12권11호
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    • pp.5164-5171
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    • 2011
  • 비선형 공정에 대한 퍼지 모델링은 일반적으로 주어진 데이터를 이용하여 입력 변수를 선정하고 각 입력 변수에 대한 입력 공간을 분할하여 이들 입력 변수 및 공간 분할에 의해 퍼지 규칙을 형성한다. 퍼지 규칙의 전반부는 입력 변수 선정, 공간 분할 수 및 소속 함수에 의해 동정되고 퍼지 규칙의 후반부는 간략 추론, 선형 추론에 의해 다항식 함수의 형태로 동정된다. 일반적으로 주어진 데이터를 이용한 비선형 공정에 대한 퍼지 규칙의 형성은 차원이 증가할수록 규칙의 수가 지수적으로 증가하는 문제를 가지고 있다. 이를 해결하기 위해 각 입력 공간의 퍼지 분할에 의한 퍼지 규칙을 개별적으로 형성함으로써 복잡한 비선형 공정을 모델링 할 수 있다. 따라서 본 논문에서는 개별적인 입력 공간을 활용하여 퍼지 규칙을 생성한다. 퍼지 규칙의 전반부 파라미터는 입력 데이터의 최소 값과 최대 값을 이용하는 최소-최대 방법을 이용하여 동정되고, 소속 함수는 삼각형, 범종형, 사다리꼴형 소속 함수를 사용한다. 마지막으로, 비선형 공정으로는 널리 이용되는 데이터를 이용하여 시스템 특성 및 성능을 평가한다.

안전도 신호 분석을 통한 지능형 로봇 제어 기법의 개발 (Development of Intelligent Robot Control Technology By Electroocculogram Analysis)

  • 김창현;이주장;김민성
    • 제어로봇시스템학회논문지
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    • 제10권9호
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    • pp.755-762
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    • 2004
  • In this research, EOG(Electrooculogram) signal was analyzed to predict the subject's intention using a fuzzy classifier. The fuzzy classifier is built automatically using the EOG data and evolutionary algorithms. An assistant robot manipulator in redundant configuration has been developed, which operates according to the EOG signal classification results. For automatic fuzzy model construction without any experts' knowledge, an evolutionary algorithm with the new representation scheme, design of adequate fitness function and evolutionary operators, is proposed. The proposed evolutionary algorithm can optimize the number of fuzzy rules, the number of fuzzy membership functions, parameter values for the each membership functions, and parameter values for the consequent parts. It is shown that the fuzzy classifier built by the proposed algorithm can classify the EOG data efficiently. Intelligent motion planner that consists of several neural networks are used for control of robot manipulator based upon EOG classification results.

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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데이터 정보를 이용한 퍼지 뉴럴 네트워크의 새로운 설계 (A New Design of Fuzzy Neural Networks Using Data Information)

  • 박건준;오성권;김현기
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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    • pp.273-275
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    • 2006
  • In this paper, we introduce a new design of fuzzy neural networks using input-output data information of target system. The proposed fuzzy neural networks is constructed by input-output data information and used the center of data distance by HCM clustering to obtain the characteristics of data. A membership function is defined by HCM clustering and is applied input-output dat included each rule to conclusion polynomial functions. We use triangular membership functions and simplified fuzzy inference, linear fuzzy inference, and modified quadratic fuzzy inference in conclusion. In the networks learning, back propagation algorithm of network is used to update the parameters of the network. The proposed model is evaluated with benchmark data.

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Hybrid Type II fuzzy system & data mining approach for surface finish

  • Tseng, Tzu-Liang (Bill);Jiang, Fuhua;Kwon, Yongjin (James)
    • Journal of Computational Design and Engineering
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    • 제2권3호
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    • pp.137-147
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    • 2015
  • In this study, a new methodology in predicting a system output has been investigated by applying a data mining technique and a hybrid type II fuzzy system in CNC turning operations. The purpose was to generate a supplemental control function under the dynamic machining environment, where unforeseeable changes may occur frequently. Two different types of membership functions were developed for the fuzzy logic systems and also by combining the two types, a hybrid system was generated. Genetic algorithm was used for fuzzy adaptation in the control system. Fuzzy rules are automatically modified in the process of genetic algorithm training. The computational results showed that the hybrid system with a genetic adaptation generated a far better accuracy. The hybrid fuzzy system with genetic algorithm training demonstrated more effective prediction capability and a strong potential for the implementation into existing control functions.

퍼지제어 시스템을 위한 인공신경망 설계 (Design of Artificial Neural Networks for Fuzzy Control System)

  • 장문석;장덕철
    • 한국정보처리학회논문지
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    • 제2권5호
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    • pp.626-633
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    • 1995
  • 퍼지 시스템 모델링에 있어서, 퍼지 규칙을 인식하고 퍼지 추론의 소속함수를 조 정하기란 매우 어렵다. 본 논문에서는 인공신경망을 이용함으로써, 자동으로 퍼지 규 칙을 인식하고 동시에 퍼지 추론의 소속함수를 조정할 수 있는 퍼지신경망 모델을 제 시하고, 인공신경망의 수렴도를 향상시키기 위해 개선된 역전파 알고리즘을 사용하여 학습에 사용하였다. 이 방법의 타당성을 로보트 매니풀레이터를 통해 검증 한다.

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최적 퍼지 제어기를 이용한 트럭의 역-주행 제어 (Truck Backer - Upper Control Using Optimal Fuzzy Control)

  • 최용길;배영철;임화영
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 하계학술대회 논문집 D
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    • pp.2666-2668
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    • 2001
  • Fuzzy system which are based on membership functions and rules, can control nonlinear, uncertian, complex system well. However, Fuzzy controller has problems: It is difficult to design a stable for amateur. To update the then-part membership functions of the fuzzy controller can be designed using the Optimal fuzzy controller. Then we could be optimized the system choosing a good performance index. The proposed fuzzy controller based on Optimal fuzzy control is an Truck-Backer for demonstration of the robustness of proposed methodology.

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다중 출력을 가지는 퍼지 관계 기반 퍼지뉴럴네트워크 설계 및 최적화 (Design of Fuzzy Relation-based Fuzzy Neural Networks with Multi-Output and Its Optimization)

  • 박건준;김현기;오성권
    • 전기학회논문지
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    • 제58권4호
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    • pp.832-839
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    • 2009
  • In this paper, we introduce an design of fuzzy relation-based fuzzy neural networks with multi-output. Fuzzy relation-based fuzzy neural networks comprise the network structure generated by dividing the entire input space. The premise part of the fuzzy rules of the network reflects the relation of the division space for the entire input space and the consequent part of the fuzzy rules expresses three types of polynomial functions such as constant, linear, and modified quadratic. For the multi-output structure the neurons in the output layer were connected with connection weights. The learning of fuzzy neural networks is realized by adjusting connections of the neurons both in the consequent part of the fuzzy rules and in the output layer, and it follows a back-propagation algorithm. In addition, in order to optimize the network, the parameters of the network such as apexes of membership functions, learning rate and momentum coefficient are automatically optimized by using real-coded genetic algorithm. Two examples are included to evaluate the performance of the proposed network.

Optimization of Fuzzy Set-Fuzzy Systems based on IG by Means of GAs with Successive Tuning Method

  • Park, Keon-Jun;Oh, Sung-Kwun;Kim, Hyun-Ki
    • Journal of Electrical Engineering and Technology
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    • 제3권1호
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    • pp.101-107
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    • 2008
  • We introduce an optimization of fuzzy set-fuzzy systems based on IG (Information Granules). The proposed fuzzy model implements system structure and parameter identification by means of IG and GAs. The concept of information granulation was coped with to enhance the abilities of structural optimization of the fuzzy model. Granulation of information realized with C-Means clustering helps determine the initial parameters of the fuzzy model such as the initial apexes of the membership functions in the premise part and the initial values of polynomial functions in the consequence part of the fuzzy rules. The initial parameters are adjusted effectively with the help of the GAs and the standard least square method. To optimally identify the structure and the parameters of the fuzzy model we exploit GAs with successive tuning method to simultaneously search the structure and the parameters within one individual. We also consider the variant generation-based evolution to adjust the rate of identification of the structure and the parameters in successive tuning method. The proposed model is evaluated with the performance of the conventional fuzzy model.

패턴 인식을 위한 Interval Type-2 퍼지 집합 기반의 최적 다중출력 퍼지 뉴럴 네트워크 (Optimized Multi-Output Fuzzy Neural Networks Based on Interval Type-2 Fuzzy Set for Pattern Recognition)

  • 박건준;오성권
    • 전기학회논문지
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    • 제62권5호
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    • pp.705-711
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    • 2013
  • In this paper, we introduce an design of multi-output fuzzy neural networks based on Interval Type-2 fuzzy set. The proposed Interval Type-2 fuzzy set-based fuzzy neural networks with multi-output (IT2FS-based FNNm) comprise the network structure generated by dividing the input space individually. The premise part of the fuzzy rules of the network reflects the individuality of the division space for the entire input space and the consequent part of the fuzzy rules expresses three types of polynomial functions with interval sets such as constant, linear, and modified quadratic inference for pattern recognition. The learning of fuzzy neural networks is realized by adjusting connections of the neurons in the consequent part of the fuzzy rules, and it follows a back-propagation algorithm. In addition, in order to optimize the network, the parameters of the network such as apexes of membership functions, uncertainty factor, learning rate and momentum coefficient were automatically optimized by using real-coded genetic algorithm. The proposed model is evaluated with the use of numerical experimentation.