• Title/Summary/Keyword: fuzzy approximate reasoning

검색결과 46건 처리시간 0.031초

암반분류에서 RMR과 Q System의 상관성 분석 (A Study on Relationship Between RMR and Q System in Rock Mass Classification)

  • 안종필;박주원;박상도
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2000년도 가을 학술발표회 논문집
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    • pp.737-744
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    • 2000
  • This paper resorts to rock mass rating and rock mass quality to draw value based on the evaluation of rock and to draw interrelation formula in relation to rock mass quality, A comparative analysis was given of survey values reported in the existing documents. This paper has tried to find out the relationship between RMR and Q System for the sake of choosing rational reinforcing patterns and of the safety of tunnels. The results run as follow: RMR=8.251n(Q)+43.83. This paper has also tried to find out the relationship between RMR and Q System by using Fuzzy Approximate Reasoning Concept. We suggest that those in charge should not depend on a single system only after evaluating the classification of rocks, and compare one result with another for the good of keeping track of the condition of base rocks in a better way.

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퍼지를 이용한 실시간 안정도 판별과 에너지 마진의 추정 (Real-time Stability Assessment and Energy Margin Estimation using Fuzzy)

  • 최원찬;김수남;유석구
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 C
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    • pp.1239-1241
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    • 1999
  • In this paper, we propose real time transient stability assessment and energy margin estimation using fuzzy approximate reasoning. The proposed method used rotor angle, kinetic energy and acceleration power of generators at clearing time as fuzzy input. In order to calculate energy margin in transient energy function (TEF), we obtained controlling unstable equilibrium point (UEP) using mode of disturbance procedure (MOD). The proposed algorithm is tested on 4-machine, 6-bus, 7-line power system to prove of effectiveness.

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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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TOLERANT FUZZY PATTERN MATCHING : AN INTRODUCTION

  • DUBOIS, DIDIER;PRADE, HENRI
    • 한국지능시스템학회논문지
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    • 제3권2호
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    • pp.3-17
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    • 1993
  • The fuzzy pattern matching technique has been developed in the framework of fuzzy set and possibility theory in order to take into account the imprecision and the uncertainty pervading values which have to be compared to requirements (which may be fuzzy) in a pattern matching process. This paper restates the basic principles and extends them to situations where (sub)patterns are only required to be satisfied up to a given tolerance (which may be fuzzy), or where the different subparts of a compound pattern may have various levels of importance. Both cases correspond to a weakening of elementary patterns. which can be expressed by a fuzzy relations modelling an approximate equality or an uncertain strict equality respectively. We also study the more sophisticated case where some elementary patterns have not to be satisfied with the highest priority provided that weaker requirements remain satisfied. The fuzzy pattern matching technique applies in a variety of problems including the evaluation of soft queries with respect to a fuzzy database, the evaluation of the fuzzy condition parts of rules in approximate reasoning, or the evaluation of the belonging of an ill-known object to a flexible class in classification problems.

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퍼지집합이론과 사례기반추론을 활용한 채권등급예측모형의 구축 (A Hybrid Approach Using Case-Based Reasoning and Fuzzy Logic for Corporate Bond Rating)

  • 김현정;신경식
    • 지능정보연구
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    • 제10권2호
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    • pp.91-109
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    • 2004
  • 최근 채권의 상환 및 이자의 확실성 정도를 측정하고 연관된 상대적인 위험의 정도를 나타내는 채권등급 평가의 중요성이 대두되고 있다. 초기의 대다수 선행 연구들에서는 기업의 채권 등급예측을 위하여 통계적 기법이 많이 사용되었으나, 많은 연구들에 의해 그 우수성이 보고되고 있는 사례기반 추론 등 인공지능 기법들이 통계모형의 대안으로 제시되어지고 있다. 사례기반 추론에서는 과거의 사례들이 지식으로 표현되고 해결 방법으로 사용된다. 유용한 사례기반 시스템을 구축하기 위해서 시스템의 지식베이스를 구축할 사례들을 인간의 정보처리 과정과 유사한 방법으로 표현하는 것이 중요하다. 본 논문은 실제 세계의 애매모호한 사례들을 다루는데 적절한 퍼지집합개념을 사례기반 추론과 결합하는 통합 방법론을 제시하고자 한다. 퍼지집합이론은 인간이 의사결정시 사용하는 유사한 자연스러운 언어를 수학적으로 변환할 수 있게 해주는 인공지능 기법이다.

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직류 서보계의 퍼지제어와 $\alpha$-레벨 퍼지집합 분해에 의한 퍼지추론 연산회로 구현 (Fuzzy Control of DC Servo System and Implemented Logic Circuits of Fuzzy Inference Engine Using Decomposition of $\alpha$-level Fuzzy Set)

  • 홍정표;홍순일;이요섭
    • Journal of Advanced Marine Engineering and Technology
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    • 제28권5호
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    • pp.793-800
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    • 2004
  • The purpose of this study is to develope a servo system with faster and more accurate response. This paper describes a method of approximate reasoning for fuzzy control of servo system based on the decomposition of $\alpha$-level fuzzy sets. We propose that fuzzy logic algorithm is a body from fuzzy inference to defuzzificaion cases where the output variable u directly is generated PWM The effectiveness for robust and faster response of the fuzzy control scheme are 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 is demonstrated successfully.

$\alpha$-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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$\alpha$-레벨집합 분해에 의한 서보제어용 퍼지추론 하드웨어의 구현 (Implement of Fuzzy Inference Hardware for Servo Control Using $\alpha$ -level Set Decomposition)

  • 홍순일;이요섭;최재용
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2001년도 전력전자학술대회 논문집
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    • pp.662-665
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    • 2001
  • As the fuzzy control is applied to servo system the hardware implementation of the fuzzy information systems requires the high speed operations, short real time control and the small size systems. The aims of this study is to develop hardware of the fuzzy information systems to be apply to servo system. In this paper, we propose a calculation method of approximate reasoning for fuzzy control based on $\alpha$-level set decomposition of fuzzy sets by quantize $\alpha$-cuts. This method can be easily implemented with analog hardware. The influence of quantization levels of $\alpha$-cuts on output from fuzzy inference engine is investigated. It is concluded that 4 quantization levels give sufficient result for fuzzy control performance of do servo system. It examined useful with experiment for dc servo system.

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퍼지근사추론을 이용한 보행 서비스수준 산정 (Estimating the Level-Of-Service for Walkways by Using Fuzzy Approximate Reasoning)

  • 김경환;박상훈;김대현
    • 대한토목학회논문집
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    • 제26권2D호
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    • pp.241-250
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    • 2006
  • 보행은 가장 권장되어야 하는 중요한 교통수단임에도 불구하고, 아직까지 구체적인 연구가 미미한 실정이다. 특히, 자동차 위주의 교통계획으로 인하여, 도로시설의 용량분석 및 서비스수준 평가를 위해 제정된 "도로용량편람(HCM)"에서 조차 보행 및 보행공간에 대한 구체적인 분석방법이 제시되어 있지 않고 있다. 그러므로 본 연구는 현재의 보행 서비스수준의 분석 기준인 보행유율에 소음수준과 주변밝기 정도를 추가로 고려하는 보행자가 직접 느끼는 서비스수준을 산정하기 위하여 퍼지근사추론을 사용하였다. 입력변수는 보행유율, 소음수준, 밝기정도를 사용하였으며 주간과 야간으로 나누어 퍼지근사추론 모형을 구축하였다. 구축된 모형의 예측력 분석은 $R^2$와 MAE 그리고 MSE를 사용하였으며 그 값은 주간모형의 경우 각각 0.803, 0.729, 0.735이고 야간모형의 경우 0.893, 0.878, 0.860으로 모형의 설명력이 높음을 보여주고 있다. 본 연구과정에서 야간의 경우 보행유율이 높을수록 밝기정도보다는 소음수준이 보행만족도에 더 큰 영향을 미치는 것을 볼 수 있었다.

유전자 알고리즘과 퍼지규칙을 기반으로한 지능형 자동감시 시스템의 개발 (A Fuzzy Logic System for Detection and Recognition of Human in the Automatic Surveillance System)

  • 장석윤;박민식;이영주;박민용
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2001년도 하계종합학술대회 논문집(3)
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    • pp.237-240
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    • 2001
  • An image processing and decision making method for the Automatic Surveillance System is proposed. The aim of our Automatic Surveillance System is to detect a moving object and make a decision on whether it is human or not. Various object features such as the ratio of the width and the length of the moving object, the distance dispersion between the principal axis and the object contour, the eigenvectors, the symmetric axes, and the areas if the segmented region are used in this paper. These features are not the unique and decisive characteristics for representing human Also, due to the outdoor image property, the object feature information is unavoidably vague and inaccurate. In order to make an efficient decision from the information, we use a fuzzy rules base system ai an approximate reasoning method. The fuzzy rules, combining various object features, are able to describe the conditions for making an intelligent decision. The fuzzy rule base system is initially constructed by heuristic approach and then, trained and tasted with input/output data Experimental result are shown, demonstrating the validity of our system.

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