• 제목/요약/키워드: Rule-based method

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퍼지 규칙기반제어기에서 시스템의 성능평가 (The Performance Evaluation of Fuzzy Rule-Based System)

  • 김영철;최종수;최한수;김성중
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1992년도 하계학술대회 논문집 A
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    • pp.261-264
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    • 1992
  • In designing the fuzzy rule-based system, it has effected by the four significant factors such as the choice of membership function, scaling factor, the numbers of fuzzy control rule, the method of defuzzification. In this paper we design the fuzzy rule based system and evaluate by three factors, as followes reaching time, overshoot, and amplitude. And then we wiII show that the significant factors are the choice of scaling factor and the numbers of fuzzy control rule, and the system performance can be improved by the proper selection of the scaling factors.

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퍼지규칙 기반 시스템에서 불필요한 속성 감축에 의한 패턴분류 (Pattern classification on the basis of unnecessary attributes reduction in fuzzy rule-based systems)

  • 손창식;김두완
    • 인터넷정보학회논문지
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    • 제8권3호
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    • pp.109-118
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    • 2007
  • 본 논문에서는 퍼지규칙 기반 시스템에서 규칙 내에 포함된 불완전한 속성을 제거하여 보다 간략화 된 규칙으로도 분류할 수 있는 방법을 제안하였다. 제안한 방법에서는 규칙 내에 포함된 불완전한 속성을 제거하기 위해 러프집합을 이용하였고 보다 명확한 분류를 위해 출력부 소속함수의 적합도가 최대인 속성들을 추출하였다. 또한 모의실험에서는 제안된 방법의 타당성을 검증하기 위해 rice taste data를 기반으로 규칙 감축 전 퍼지 max-product 결과와 규칙 감축 후 퍼지 max-product 결과를 비교하였다. 그 결과, 규칙 감축 전 max-product 결과와 규칙 감축 후 max-product 결과가 정확히 일치함을 볼 수 있었고, 보다 객관적인 검증을 위해 비퍼지화 된 실수 구간을 비교하였다.

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연삭가공 트러블슈팅을 위한 룰베이스 구성의 기초 (Basic Construction of Rule-Base for Grinding Trouble-shooting)

  • 이재경
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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    • pp.492-497
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    • 1999
  • Cognition and control of grinding trouble occurring during the grinding process are classified into a quantitative knowledge which depends on experimental data and qualitative knowledge which relies on skillful engineers. Grinding operations include a large number of functional parameters, since there are several ways of coping with grinding trouble. One is the qualitative method which depends on empirical knowledge utilizing the skilful experts from the workshop, the other is the quantitative method which utilizes the experimental data obtained by sensor. But, they are all difficult to accomplish from the grinding trouble-shooting system. The reason is that grinding troubles are not easily controlled in the quantitative method, and therefore, trouble-shooting has mainly relied on the knowledge of skilful engineers. Thus, there is an important issue of how a grinding trouble-shooting system can be designed and what knowledge is utilized among the large amount of grinding trouble information. In this paper, basic strategy to develop the grinding database of rule-based rule, which is strongly depended upon experience and intuition, is described.

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빈발도와 가중치를 이용한 서비스 연관 규칙 마이닝 (Mining Association Rule on Service Data using Frequency and Weight)

  • 황정희
    • 디지털콘텐츠학회 논문지
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    • 제17권2호
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    • pp.81-88
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    • 2016
  • 일반적인 빈발패턴 탐사 방법은 항목의 빈발도만을 고려한다. 그러나 유용한 정보를 추출하는 데 있어 빈발도와 더불어 고려해야 하는 것은 빈발항목이 아니더라도 연관된 항목이 주기적으로 함께 발생한다면 시기나 시간에 따라 관심의 중요도가 변화하는 것을 고려해야 한다. 즉, 시간에 따라 사용자가 요구하는 서비스의 중요도는 다르므로 각 서비스 항목에 대한 중요도의 값을 고려하여 마이닝 하는 방법이 필요하다. 본 논문에서는 서비스 온톨로지 기반으로 가중치를 이용한 서비스 빈발 패턴을 추출하는 마이닝 기법을 제안한다. 제안하는 기법은 시공간 상황을 기반으로 서비스의 중요도를 고려한 가중치를 부여하여 연관 서비스를 발견한다. 새롭게 탐사되는 서비스는 저장되어 있는 서비스 규칙과의 새로운 조합을 통해 사용자에게 최적의 서비스 정보를 제공할 수 있는 기반이 된다.

충돌회피환경에서의 퍼지 규칙 기반 멀티 모바일 로봇 시스템 (Multi-Mobile Robot System with Fuzzy Rule based Structure in Collision avoidance)

  • 김동원;이종호
    • 제어로봇시스템학회논문지
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    • 제16권3호
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    • pp.233-238
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    • 2010
  • This paper describes a multi-mobile robot system with fuzzy rule based structure in collision avoidance. Collision avoidance is an important function to perform a given task collaboratively and cooperatively in multi-mobile robot environments. So the important but challenging problem is handled in this paper. Considered obstacles for collision avoidance between multi mobile robots are static, dynamic, or both of them at the same time. Using the fuzzy rule based structure, distance and angle from a robot to obstacles are described as fuzzy linguistic values and steering angle for the robot are updated from the collision environments. As a result, the multi-mobile robot can modify a global path from a robot itself to its own target. In addition, avoiding collision with static or dynamic obstacles for the robot system can be achieved. Simulation based experimental results are given to show usefulness of this method.

진화론적 최적 규칙베이스 퍼지다항식 뉴럴네트워크 (Genetically Optimized Rule-based Fuzzy Polynomial Neural Networks)

  • 박병준;김현기;오성권
    • 제어로봇시스템학회논문지
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    • 제11권2호
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    • pp.127-136
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    • 2005
  • In this paper, a new architecture and comprehensive design methodology of genetically optimized Rule-based Fuzzy Polynomial Neural Networks(gRFPNN) are introduced and a series of numeric experiments are carried out. The architecture of the resulting gRFPNN results from asynergistic usage of the hybrid system generated by combining rule-based Fuzzy Neural Networks(FNN) with polynomial neural networks (PNN). FNN contributes to the formation of the premise part of the overall rule-based structure of the gRFPNN. The consequence part of the gRFPNN is designed using PNNs. At the premise part of the gRFPNN, FNN exploits fuzzy set based approach designed by using space partitioning in terms of individual variables and comes in two fuzzy inference forms: simplified and linear. As the consequence part of the gRFPNN, the development of the genetically optimized PNN dwells on two general optimization mechanism: the structural optimization is realized via GAs whereas in case of the parametric optimization we proceed with a standard least square method-based learning. To evaluate the performance of the gRFPNN, the models are experimented with the use of several representative numerical examples. A comparative analysis shows that the proposed gRFPNN are models with higher accuracy as well as more superb predictive capability than other intelligent models presented previously.

Structure Preserving Dimensionality Reduction : A Fuzzy Logic Approach

  • Nikhil R. Pal;Gautam K. Nandal;Kumar, Eluri-Vijaya
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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    • pp.426-431
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    • 1998
  • We propose a fuzzy rule based method for structure preserving dimensionality reduction. This method selects a small representative sample and applies Sammon's method to project it. The input data points are then augmented by the corresponding projected(output) data points. The augmented data set thus obtained is clustered with the fuzzy c-means(FCM) clustering algorithm. Each cluster is then translated into a fuzzy rule for projection. Our rule based system is computationally very efficient compared to Sammon's method and is quite effective to project new points, i.e., it has good predictability.

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Overlap Margin 확보 및 Side-lobe 억제를 위한 Scattering Bar Optical Proximity Correction (Scattering Bar Optical Proximity Correction to Suppress Overlap Error and Side-lobe in Semiconductor Lithography Process)

  • 이흥주
    • 한국산학기술학회논문지
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    • 제4권1호
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    • pp.22-26
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    • 2003
  • Attenuated PSM lithography 공정에서 overlay margin 확보 및 side-lobe 제거를 위해 기존의 Cr shield 방식의 단점인 복잡한 mask 제작공정과 구조를 단순화하기 위한 방법으로 scattering bar 방식을 제안하였다. Scattering bar는 Cr 보조패턴처럼 완전히 빛을 차단하는 것이 아니라 약간의 빛을 투과시켜 보강된 intensity를 상쇄하므로 side-lobe를 억제하는 방법으로 metal pattern을 생성할 때 scattering bar도 동시에 만들어 mask제작에 필요한 공정횟수를 줄이고 mask구조 역시 단순하게 한다 그리고 동시에 DOF(depth of focus)를 향상시킨다. Background clear pattern의 경우에 발생하는 side-lobe도 scattering bar를 이용하여 효율적으로 제거되었다.

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사례 기반 추론 시스템에서 적응 지식 자동 획득 모델에 관한 연구 (A Study on Adaptive Knowledge Automatic Acquisition Model from Case-Based Reasoning System)

  • 이상범;김영천;이재훈;이성주
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2002년도 춘계학술대회 및 임시총회
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    • pp.81-86
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    • 2002
  • In current CBR(Case-Based Reasoning) systems, the case adaptation is usually performed by rule-based method that use rules hand-coded by the system developer. So, CBR system designer faces knowledge acquisition bottleneck similar to those found in traditional expert system design. In this thesis, 1 present a model for learning method of case adaptation knowledge using case base. The feature difference of each pair of cases are noted and become the antecedent part of an adaptation rule, the differences between the solutions in the compared cases become the consequent part of the rule. However, the number of rules that can possibly be discovered using a learning algorithm is enormous. The first method for finding cases to compare uses a syntactic measure of the distance between cases. The threshold fur identification of candidates for comparison is fixed th the maximum number of differences between the target and retrived case from all retrievals. The second method is to use similarity metric since the threshold method may not be an accurate measure. I suggest the elimination method of duplicate rules. In the elimination process, a confidence value is assigned to each rule based on its frequency. The learned adaptation rules is applied in riven target Problem. The basic. process involves search for all rules that handle at least one difference followed by a combination process in which complete solutions are built.

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Content Addressable Memory를 이용한 Production System에서의 Rule 선택에 관한 연구 (A CAM Approach to the Selection of Rules in a Production System)

  • 백무철;김재희
    • 한국통신학회논문지
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    • 제12권1호
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    • pp.50-59
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    • 1987
  • 많은 production rule(혹은 간단히 production)로부터 현 상태에 만족되는 rule을 빨리 찾아내기 위하여 현재까지는 RAM(Ramdom Access Memory)에 탕을 둔 필터(filter)사용등의 여러 방법에 제시되었으나, 본 연구에서는 보다 효율적인 CAM(Content Addressable Memory)의 이용을 제시하고, 이를 위해 CAM의 각 bit에 따라, 용도에 다른 구분 및 데이터 구조를 설계하고, 이를 컴퓨터 시뮬레이션을 통해 기존 RAM을 사용했을 경우와 비교하였다.

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