• 제목/요약/키워드: Nonlinear Inference

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퍼지 클러스터를 이용한 비선형 추론 (Nonlinear Inference Using Fuzzy Cluster)

  • 박건준;이동윤
    • 디지털융복합연구
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    • 제14권1호
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    • pp.203-209
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    • 2016
  • 본 논문에서는 퍼지 클러스터를 이용한 비선형 추론을 위한 퍼지 추론 시스템을 소개한다. 전형적으로, 비선형 추론을 위한 퍼지 규칙의 생성은 일반적으로 입력 벡터 차원이 증가하면 규칙의 수가 지수적으로 증가하게 된다. 이러한 문제점을 해결하기 위해, 퍼지 클러스터를 표현할 수 있는 퍼지 클러스터링 알고리즘을 이용하여 입력 벡터 공간을 분산 형태로 분할하여 퍼지 모델의 규칙을 설계한다. 이러한 방법으로 복잡하고 비선형적인 공정을 퍼지 모델링 할 수 있다. 퍼지 규칙의 전반부는 퍼지 클러스터를 갖는 FCM 클러스터링 알고리즘에 의해 결정된다. 퍼지 규칙의 후반부는 4가지 형태의 다항식 함수의 형태를 가지며, 각 규칙의 후반부 파라미터들은 표준 최소자승법을 이용함으로써 추정된다. 그리고 비선형 공정의 특성 및 성능을 평가하기 위하여 비선형 공정으로 많이 이용되고 있는 데이터를 이용한다. 실험 결과는 비선형 추론이 가능하다는 것을 보여준다.

Nonlinear Characteristics of Fuzzy Scatter Partition-Based Fuzzy Inference System

  • Park, Keon-Jun;Huang, Wei;Yu, C.;Kim, Yong K.
    • International journal of advanced smart convergence
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    • 제2권1호
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    • pp.12-17
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    • 2013
  • This paper introduces the fuzzy scatter partition-based fuzzy inference system to construct the model for nonlinear process to analyze nonlinear characteristics. The fuzzy rules of fuzzy inference systems are generated by partitioning the input space in the scatter form using Fuzzy C-Means (FCM) clustering algorithm. The premise parameters of the rules are determined by membership matrix by means of FCM clustering algorithm. The consequence part of the rules is represented in the form of polynomial functions and the parameters of the consequence part are estimated by least square errors. The proposed model is evaluated with the performance using the data widely used in nonlinear process. Finally, this paper shows that the proposed model has the good result for high-dimension nonlinear process.

뉴로 퍼지 시스템을 이용한 비선형 시스템의 IMC 제어기 설계 (Design of IMC Controller for Nonlinear Systems by Using Adaptive Neuro-Fuzzy Inference System)

  • 강정규;김정수;김성호
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.236-236
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    • 2000
  • Control of Industrial processes is very difficult due to nonlinear dynamics, effect of disturbances and modeling errors. M.Morari proposed Internal Model Control(IMC) system that can be effectively applied to the systems with model uncertainties and time delays. The advantage of IMC systems is their robustness with respect to a model mismatch and disturbances. But it was difficult to apply for nonlinear systems. Adaptive Neuro-Fuzzy Inference System which contains multiple linear models as consequent part is used to model nonlinear systems. Generally, the linear parameters in neuro-fuzzy inference system can be effectively utilized to identify a nonlinear dynamical systems. In this paper, we propose new IMC design method using adaptive neuro-fuzzy inference system for nonlinear plant. Numerical simulation results show that proposed IMC design method has good performance than classical PID controller.

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A TSK fuzzy model optimization with meta-heuristic algorithms for seismic response prediction of nonlinear steel moment-resisting frames

  • Ebrahim Asadi;Reza Goli Ejlali;Seyyed Arash Mousavi Ghasemi;Siamak Talatahari
    • Structural Engineering and Mechanics
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    • 제90권2호
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    • pp.189-208
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    • 2024
  • Artificial intelligence is one of the efficient methods that can be developed to simulate nonlinear behavior and predict the response of building structures. In this regard, an adaptive method based on optimization algorithms is used to train the TSK model of the fuzzy inference system to estimate the seismic behavior of building structures based on analytical data. The optimization algorithm is implemented to determine the parameters of the TSK model based on the minimization of prediction error for the training data set. The adaptive training is designed on the feedback of the results of previous time steps, in which three training cases of 2, 5, and 10 previous time steps were used. The training data is collected from the results of nonlinear time history analysis under 100 ground motion records with different seismic properties. Also, 10 records were used to test the inference system. The performance of the proposed inference system is evaluated on two 3 and 20-story models of nonlinear steel moment frame. The results show that the inference system of the TSK model by combining the optimization method is an efficient computational method for predicting the response of nonlinear structures. Meanwhile, the multi-vers optimization (MVO) algorithm is more accurate in determining the optimal parameters of the TSK model. Also, the accuracy of the results increases significantly with increasing the number of previous steps.

적응 뉴로 퍼지추론 기법에 의한 비선형 시스템의 구조 동정에 관한 연구 (Structure Identification of Nonlinear System Using Adaptive Neuro-Fuzzy Inference Technique)

  • 이준탁;정형환;심영진;김형배;박영식
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1996년도 추계학술대회 학술발표 논문집
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    • pp.298-301
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    • 1996
  • This paper describes the structure Identification of nonlinear function using Adaptive Neuro-Fuzzy Inference Technique(ANFIS). Nonlinear mapping relationship between inputs and outputs were modeled by Sugeno-Takaki's Fuzzy Inference Method. Specially, the consequent parts were identified using a series of 1st order equations and the antecedent parts using triangular type membership function or bell type ones. According to learning Rules of ANFIS, adjustable parameters were converged rapidly and accurately.

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뉴로 퍼지 시스템을 이용한 비선형 시스템의 IMC 제어기 설계 (Design of IMC for Nonlinear Systems by Using Adaptive Neuro-Fuzzy Inference System)

  • 김성호;강정규
    • 제어로봇시스템학회논문지
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    • 제7권11호
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    • pp.958-961
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    • 2001
  • Control of Industrial processes is very difficult due to nonlinear dynamics, effect of disturbances and modeling errors. M.Morari proposed Internal Model Control(IMC) system that can be effectively applied to the systems with model uncertainties and time delays. The advantage of IMC is their robustness with respect to a model mismatch and disturbances. But it is difficult to apply for nonlinear systems. ANFIS(Adaptive Neuro-Fuzzy Inference System) which contains multiple linear models as consequent part is used to model nonlinear systems. Generally, the linear parameters in ANFIS can be effectively utilized to control a nonlinear systems. In this paper, we propose new ANFIS-based IMC controller for nonlinear systems. Numerical simulation results show that the proposed control scheme has good performances.

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A Study on an Adaptive Membership Function for Fuzzy Inference System

  • Bang, Eun-Oh;Chae, Myong-Gi;Lee, Snag-Bae;Tack, Han-Ho;Kim, Il
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1998년도 추계학술대회 학술발표 논문집
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    • pp.532-538
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    • 1998
  • In this paper, a new adaptive fuzzy inference method using neural network based fuzzy reasoning is proposed to make a fuzzy logic control system more adaptive and more effective. In most cases, the design of a fuzzy inference system rely on the method in which an expert or a skilled human operator would operate in that special domain. However, if he has not expert knowledge for any nonlinear environment, it is difficult to control in order to optimize. Thus, using the proposed adaptive structure for the fuzzy reasoning system can controled more adaptive and more effective in nonlinear environment for changing input membership functions and output membership functions. The proposed fuzzy inference algorithm is called adaptive neuro-fuzzy control(ANFC). ANFC can adapt a proper membership function for nonlinear plant, based upon a minimum number of rules and an initial approximate membership function. Nonlinear function approximation and rotary inverted pendulum control system ar employed to demonstrate the viability of the proposed ANFC.

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간편간접추론방법을 이용한 비선형 퍼지 I+PD 제어기의 설계 (Design of Nonlinear Fuzzy I+PD Controller Using Simplified Indirect Inference Method)

  • 채창현;채석;박재완;윤명기
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 G
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    • pp.2898-2901
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    • 1999
  • This paper describes the design of nonlinear fuzzy I+PD controller using simplified indirect inference method. First, the fuzzy I+PD controller is derived from the conventional continuous time linear I+PD controller. Then the fuzzification, control-rule base, and defuzzification using SIIM in the design of the fuzzy controller are discussed in detail. The resulting controller is a discrete time fuzzy version of the conventional I+PD controller. which has the same linear structure. but are nonlinear functions of the input signals. The proposed controller enhances the self-tuning control capability. Particularly when the process to be controlled is nonlinear When the SIIM is applied, the fuzzy inference results can be calculated with splitting fuzzy variables into each action component and are determined as the functional form of corresponding variables. So the proposed method has the capability of the high speed inference and adapting with increasing the number of the fuzzy input variables easily. Computer simulation results have demonstrated the superior to the control performance of the one Proposed by D. Misir et at.

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비선형 시스템 제어를 위한 모듈화 피지추론 시스템 (Modular Fuzzy Inference Systems for Nonlinear System Control)

  • 권오신
    • 한국지능시스템학회논문지
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    • 제11권5호
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    • pp.395-399
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    • 2001
  • 이 논문은 학습을 통해 관측 데이터로부터 퍼지 추론 모듈을 생성할 수 있는 적응 능력을 갖는 모듈화 퍼지추론 시스템을 제안한다. 제안한 시스템은 TS 퍼지모델과 모듈화 신경회로망의 구조적 유사성을 기초로 한다. 학습과정은 새로운 퍼지추론 모듈의 생성과 모듈 파라미터의 갱신으로 구성된다. 퍼지추론 모듈은 국부모델망과 퍼지 게이팅망으로 구성된다. 제안한 시스템의 파라미터들은 표준 LMS 알고리즘을 이용하여 최적화된다. 제안한 시스템의 성능은 비선형 동적 시스템 적응제어에의 응용을 통해서 입증된다.

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적응 펴지 추론기법을 이용한 Ball and Beam 시스템의 안정화 제어 (Stabilization Control of Ball and Beam System Using Adaptive Fuzzy Inference Technique)

  • 김태우;김형배;심영진;손영대;이준탁
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 하계학술대회 논문집 B
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    • pp.720-723
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    • 1997
  • The characteristics of ball and beam system using fuzzy inference technique can be described by fuzzy modeling. Therefore, this paper introduces a technique for fuzzy structure identification of nonlinear Input-output relation- ship using an adaptive fuzzy inference system. And the simulation result using adaptive fuzzy inference technique shows its effectiveness for fuzzy structure identification of nonlinear system.

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