• Title/Summary/Keyword: Fuzzy Functions

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

  • Park, Keon-Jun;Lee, Dong-Yoon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.11
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    • pp.5164-5171
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    • 2011
  • In fuzzy modeling for nonlinear process, typically using the given data, the fuzzy rules are formed by the input variables and the space division by selecting the input variable and dividing the input space for each input variables. The premise part of the fuzzy rule is identified by selection of the input variables, the number of space division and membership functions and the consequent part of the fuzzy rule is identified by polynomial functions in the form of simplified and linear inference. In general, formation of fuzzy rules for nonlinear processes using the given data have the problem that the number of fuzzy rules exponentially increases. To solve this problem complex nonlinear process can be modeled by separately forming the fuzzy rules by means of fuzzy division of each input space. Therefore, this paper utilizes individual input space to generate fuzzy rules. The premise parameters of the fuzzy rules are identified by Min-Max method using the minimum and maximum values of input data set and membership functions are used as a series of triangular, gaussian-like, trapezoid-type membership functions. And lastly, using the data which is widely used in nonlinear process we evaluate the performance and the system characteristics.

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

  • Kim Chang-Hyun;Lee Ju-Jang;Kim Min-Soeng
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.9
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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.

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

  • Jang, Mun-Seok;Jang, Deok-Cheol
    • The Transactions of the Korea Information Processing Society
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    • v.2 no.2
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    • pp.209-214
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    • 1995
  • It is very hard to identify the fuzzy rules and tune the membership functions of the fuzzy reasoning in fuzzy systems modeling .We propose a method which canautomatically identify the fuzzy rules and tune the membership functions of fuzzy reasoning simultaneously using artifical neural network. In this model,fuzzy rules are identified by backpropagation algorithm. The feasibility of the method is simulated by a simple robot manipulator.

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

  • Park, Keon-Jun;Oh, Sung-Kwun;Kim, Hyun-Ki
    • Proceedings of the KIEE Conference
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    • 2006.04a
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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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    • v.2 no.3
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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.

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

  • Jang, Mun-Seok;Jang, Deok-Cheol
    • The Transactions of the Korea Information Processing Society
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    • v.2 no.5
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    • pp.626-633
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    • 1995
  • It is vary hard to identify the fuzzy rules and tune the membership functions of the fuzzy inference in fuzzy systems modeling, We propose a fuzzy neural network model which can automatically identify the fuzzy rules and tune the membership functions of fuzzy inference simultaneously using artificial neural networks, and modify backpropagation algorithm for improving the convergence. The proposed method is verified by the simulation for a robot manipulator.

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

  • Choi, Yong-Gil;Bae, Yong-Chul;Yim, Wha-Yeong
    • Proceedings of the KIEE Conference
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    • 2001.07d
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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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Design of Fuzzy Relation-based Fuzzy Neural Networks with Multi-Output and Its Optimization (다중 출력을 가지는 퍼지 관계 기반 퍼지뉴럴네트워크 설계 및 최적화)

  • Park, Keon-Jun;Kim, Hyun-Ki;Oh, Sung-Kwun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.4
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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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    • v.3 no.1
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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.

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

  • Park, Keon-Jun;Oh, Sung-Kwun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.5
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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.