• Title/Summary/Keyword: fuzzy rule-based system

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A Cooperative Spectrum Sensing Scheme Using Fuzzy Logic for Cognitive Radio Networks

  • Thuc, Kieu-Xuan;Koo, In-Soo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.4 no.3
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    • pp.289-304
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    • 2010
  • This paper proposes a novel scheme for cooperative spectrum sensing on distributed cognitive radio networks. A fuzzy logic rule - based inference system is proposed to estimate the presence possibility of the licensed user's signal based on the observed energy at each cognitive radio terminal. The estimated results are aggregated to make the final sensing decision at the fusion center. Simulation results show that significant improvement of the spectrum sensing accuracy is achieved by our schemes.

Fuzzy Modeling Technique of Nonlinear Dynamical System and Its Stability Analysis (비선형 시스템의 퍼지 모델링 기법과 안정도 해석)

  • So, Myeong Ok;Ryu, Gil Su;Lee, Jun Tak
    • Journal of Advanced Marine Engineering and Technology
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    • v.20 no.2
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    • pp.101-101
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    • 1996
  • This paper presents the linearized fuzzy modeling technique of nonlinear dynamical system and the stability analysis of fuzzy control system. Firstly, the nonlinear system is partitionized by multiple linear fuzzy subcontrol systems based on fuzzy linguistic variables and fuzzy rules. Secondly, the disturbance adaptaion controllers which guarantee the global asymptotic stability of each fuzzy subsystem by an optimal feedback control law are designed and the stability analysis procedures of the total fuzzy control system using Lyapunov functions and eigenvalues are discussed in detail through a given illustrative example.

Fuzzy Modeling Technique of Nonlinear Dynamic System and Its Stability Analysis (비선형 시스템의 퍼지 모델링 기법과 안정도 해석)

  • 소명옥;류길수;이준탁
    • Journal of Advanced Marine Engineering and Technology
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    • v.20 no.2
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    • pp.33-39
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    • 1996
  • This paper presents the linearized fuzzy modeling technique of nonlinear dynamical system and the stability analysis of fuzzy control system. Firstly, the nonlinear system is partitionized by multiple linear fuzzy subcontrol systems based on fuzzy linguistic variables and fuzzy rules. Secondly, the disturbance adaptaion controllers which guarantee the global asymptotic stability of each fuzzy subsystem by an optimal feedback control law are designed and the stability analysis procedures of the total fuzzy control system using Lyapunov functions and eigenvalues are discussed in detail through a given illustrative example.

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The neural network controller design with fuzzy-neuraon and its application to a ball and beam (볼과 빔 제어를 위한 퍼지 뉴론을 갖는 신경망 제어기 설계)

  • 신권석
    • Proceedings of the IEEK Conference
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    • 1998.06a
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    • pp.897-900
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    • 1998
  • Through fuzzy logic controller is very useful to many areas, it is difficult to build up the rule-base by experience and trial-error. So, effective self-tuning fuzzy controller for the position control of ball and beam is designed. In this paper, we developed the neural network control system with fuzzy-neuron which conducts the adjustment process for the parameters to satisfy have nonlinear property of the ball and beam system. The proposed algorithm is based on a fuzzy logic control system using a neural network learinign algorithm which is a back-propagation algorithm. This system learn membership functions with input variables. The purpose of the design is to control the position of the ball along the track by manipulating the angualr position of the serve. As a result, it is concluded that the neural network control system with fuzzy-neuron is more effective than the conventional fuzzy system.

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Design of Type-2 FCM-based Fuzzy Inference Systems and Its Optimization (Type-2 FCM 기반 퍼지 추론 시스템의 설계 및 최적화)

  • Park, Keon-Jun;Kim, Yong-Kab;Oh, Sung-Kwun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.11
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    • pp.2157-2164
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    • 2011
  • In this paper, we introduce a new category of fuzzy inference system based on Type-2 fuzzy c-means clustering algorithm (T2FCM-based FIS). The premise part of the rules of the proposed model is realized with the aid of the scatter partition of input space generated by Type-2 FCM clustering algorithm. The number of the partition of input space is composed of the number of clusters and the individual partitioned spaces describe the fuzzy rules. Due to these characteristics, we can alleviate the problem of the curse of dimensionality. The consequence part of the rule is represented by polynomial functions with interval sets. To determine the structure and estimate the values of the parameters of Type-2 FCM-based FIS we consider the successive tuning method with generation-based evolution by means of real-coded genetic algorithms. The proposed model is evaluated with the use of numerical experimentation.

Auto-Generation of Fuzzy Rule Base Using Genetic Algorithm (유전 알고리즘을 이용한 퍼지 규칙 베이스의 자동생성)

  • 박세희;김용호;심귀보;전홍태
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.29B no.2
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    • pp.60-68
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    • 1992
  • Fuzzy logic rule based controller has many desirable advantages, whih are simple to implement on the real time and need not the information of structure and dynamic characteristics of the system. Thus, nowadays, the scope of the application of the fuzzy logic controller becomes enlarged. But, if the controlled plant is a time-varying/nonlinear system, it is not easy to construct the fuzzy logic rules which need the knowledge of and expert. In this paper, an approach by which the logic control rules can be auto-generated using the genetic algorithm that is known to be very effective in the optimization problem will be proposed and the effectiveness of the proposed approach will be verified by computer simulation of the 2 d.o.f. planner robot.

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Self-Organization of Fuzzy Rule Base Using Genetic Algorithm

  • Park, Sae-Hie;Kim, Yong-Ho;Choi, Young-Keel;Cho, Hyun-Chan;Jeon, Hong-Tae
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1993.06a
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    • pp.881-886
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    • 1993
  • Fuzzy logic rule-based controller has many desirable advantages, which are simple to implement on the real time and need not the information of structure and dynamic characteristics of the system. Thus, nowadays, the scope of the application of the fuzzy logic controller becomes enlarged. But, if the controlled plant is a time-varying and nonlinear system, it is not easy to construct the fuzzy logic rules which usually need the knowledge of an expert. In this paper, an approach in which the logic control rules can be self-organized using genetic algorithm will be proposed and the effectiveness of the proposed method will be verified by computer simulation of the 2 d.o.f. planar robot manipulator.

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A New Learning Algorithm of Neuro-Fuzzy Modeling Using Self-Constructed Clustering

  • Ryu, Jeong-Woong;Song, Chang-Kyu;Kim, Sung-Suk;Kim, Sung-Soo
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.5 no.2
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    • pp.95-101
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    • 2005
  • In this paper, we proposed a learning algorithm for the neuro-fuzzy modeling using a learning rule to adapt clustering. The proposed algorithm includes the data partition, assigning the rule into the process of partition, and optimizing the parameters using predetermined threshold value in self-constructing algorithm. In order to improve the clustering, the learning method of neuro-fuzzy model is extended and the learning scheme has been modified such that the learning of overall model is extended based on the error-derivative learning. The effect of the proposed method is presented using simulation compare with previous ones.

Skin Color Extraction in Varying Backgrounds and illumination Conditions

  • Park, Minsick;Park, Chang-Woo;Kim, Won-ha;Park, Mignon
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.162.4-162
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    • 2001
  • This paper presents a fuzzy-based method for classification skin color object in a complex background under varying illumination Parameters of fuzzy rule base are generated using a genetic algorithm(GA). The color model is used in the YCbCr color space. We propose a unique fuzzy system in order to accommodate varying background color and illumination condition This fuzzy system approach to skin color classification is discussed along with an overview of YCbCr color space.

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Neuro-Fuzzy System and Its Application by Input Space Partition Methods (입력 공간 분할에 따른 뉴로-퍼지 시스템과 응용)

  • 곽근창;유정웅
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1998.10a
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    • pp.433-439
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    • 1998
  • In this paper, we present an approach to the structure identification based on the input space partition methods and to the parameter identification by hybrid learning method in neuro-fuzzy system. The structure identification can automatically estimate the number of membership function and fuzzy rule using grid partition, tree partition, scatter partition from numerical input-output data. And then the parameter identification is carried out by the hybrid learning scheme using back-propagation and least squares estimate. Finally, we sill show its usefulness for neuro-fuzzy modeling to truck backer-upper control.

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