• Title/Summary/Keyword: fuzzy theory

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A Design and Implementation of Diagnosis System of Learning Misconception by Using Fuzzy Theory (퍼지 이론을 이용한 학습오인 진단 시스템 설계 및 구현)

  • Lee, Hyeon-No;Ra, Sang-Suk;Choi, Yeong-Sik
    • Journal of Digital Convergence
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    • v.4 no.2
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    • pp.143-151
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    • 2006
  • The purpose of this paper is to make a design and implementation of a diagnosis system of learning misconception of students who learn 'be' verb in the English language by using fuzzy theory. In this system, a fuzzy cognitive map exposes the fact that students' perception and misunderstanding about 'the English' language have an intertwined relationship, and diagnoses causes of misconceptions of students by using fuzzy memory associative memory. It suggests that since most existing systems of rule based expert system have had several limitations, this system will be applied to diagnose learners' misconception of learning in varieties of education areas.

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Shortest Path Problem in a Type-2 Fuzzy Weighted Graph (타입 2-퍼지 가중치 그래프에서 최단경로 문제)

  • 이승수;이광형
    • Journal of the Korean Institute of Intelligent Systems
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    • v.11 no.6
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    • pp.528-531
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    • 2001
  • Finding a shortest path on a graph is a fundamental problem in the area of graph theory. In an application where we cannot exactly determine the weights of edges fuzzy weights can be used instead of crisp weights. and Type-2 fuzzy weight will be more suitable of this uncertainty varies under some conditions. In this paper, shortest path problem in type-1 fuzzy weighted graphs is extended for type 2 fuzzy weighted graphes. A solution is also given based on possibility theory and extension principle.

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Evaluation of Stress Response and Recovery using Biosignals and Fuzzy Theory (생체신호와 퍼지이론을 이용한 스트레스에 대한 반응과 회복의 평가)

  • Seol, A-Ram;Sin, Jae-U;Seong, Hong-Mo;Lee, Cheol-Gyu;Yun, Yeong-Ro
    • Journal of the Ergonomics Society of Korea
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    • v.21 no.2
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    • pp.59-70
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    • 2002
  • This paper is about the evaluation of stress response and recovery using biosignals and fuzzy theory. We caused mental stress by means of a coin-stacking task. During the experiment, 4 kinds of biosignals, including frontalis EMG, ECG, peripheral skin temperature and skin conductance level, were acquired. Then, the degree of stress was assessed by synthetically those signals using fuzzy inference. From the fuzzy inference result, the parameters (amount of physiological change / amount of imposed stress) and (time to 25% recovery), which represent response and recovery respectively, were derived. We made a two-dimensional point graph using the response parameter as an abscissa and the recovery parameter as an ordinate for each subject.

A Study on Selection of Effective Supplier and Analysis of Evaluation Structure in Supply Chain Management (공급체인 관리하에서 효율적인 협력업체 선정 및 평가구조 분석에 관한 연구)

  • Kim, Jin-Ho;Lee, Byoung-Ki
    • IE interfaces
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    • v.17 no.2
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    • pp.169-179
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    • 2004
  • In supply chain management, supplier capacity is very important to meet the customer demand quickly. This paper studies a supplier evaluation structure and then suggests a methodology using fuzzy theory for selecting an effective supplier. Several quantitative and qualitative evaluation factors should be analyzed in the evaluation structure. The qualitative factors includes not only product and service qualities but financial condition. The methodology deals with both the quantitative and qualitative factors together through fuzzy inference. A case study is also presented to show how to choose the best one among potential suppliers.

A Design and Implementation of Diagnosis System of Learning Misconception by Using Fuzzy Theory (퍼지 이론을 이용한 영어학습 진단 시스템 설계 및 구현)

  • Lee, Hyeon-No;Ra, Sang-Suk;Choe, Yeong-Sik
    • 한국디지털정책학회:학술대회논문집
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    • 2006.06a
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    • pp.451-459
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    • 2006
  • The purpose of this paper is to make a design and implementation of a diagnosis system of learning misconception of students who learn 'be' verb in the English language by using fuzzy theory. In this system, a fuzzy cognitive map exposes the fact that students' perception and misunderstanding about 'the English' language have an intertwined relationship, and diagnoses causes of misconceptions of students by using fuzzy memory associative memory. It suggests that since most existing systems of rule based expert system have had several limitations, this system will be applied to diagnose learners' misconception of learning in varieties of education areas.

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Parametric Design on Bellows of Piping System Using Fuzzy Knowledge Processing

  • Lee Yang-Chang;Lee Joon-Seong;Choi Yoon-Jong
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.6 no.2
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    • pp.144-149
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    • 2006
  • This paper describes a novel automated analysis system for bellows of piping system. An automatic finite element (FE) mesh generation technique, which is based on the fuzzy theory and computational geometry technique, is incorporated into the system, together with one of commercial FE analysis codes and one of commercial solid modelers. In this system, a geometric model, i.e. an analysis model, is first defined using a commercial solid modelers for 3-D shell structures. Node is generated if its distance from existing node points is similar to the node spacing function at the point. The node spacing function is well controlled by the fuzzy knowledge processing. The Delaunay triangulation technique is introduced as a basic tool for element generation. The triangular elements are converted to quadrilateral elements. Practical performances of the present system are demonstrated through several analysis for bellows of piping system.

Fuzzy Expert System for Fault Diagnosis of Hard Disk Drive Test Systems (Hard Disk Drive 검사 시스템의 고장 진단용 퍼지 전문가 시스템)

  • Nam, Chang-Woo;Park, Mign-On;Moon, Un-Chul
    • Proceedings of the KIEE Conference
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    • 2002.11c
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    • pp.597-600
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    • 2002
  • This paper has been studied expert system using fuzzy theory for fault diagnosis of HDD test systems by detecting systems fault and presenting the way of repair using test history and rule base built via interview from exports. The rules of fault diagnosis of HDD test systems are classified into 2 types, fuzzy and crisp, and these have been serialized to decide whether fault diagnosis be done or not by fuzzy rules and to present the way of repair by crisp rules. And then this paper has designed expert system using fuzzy theory for fault diagnosis.

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Size and Shape Discrete Optimum Design of Planar and Spacial Steel Structures Using Fuzzy-Genetic Algorithms (퍼지-유전자알고리즘에 의한 평면 및 입체 강구조물의 단면/형상 이산화 최적설계)

  • Park, Choon-Wook;Yuh, Baeg-Youh;Kim, Su-Won
    • Proceeding of KASS Symposium
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    • 2005.05a
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    • pp.236-245
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    • 2005
  • This paper was developed the discrete optimum design program by the refined fuzzy-genetic algorithms based on the genetic algorithms and fuzzy theory. The optimum design of this paper can perform both size and shape optimum design for planar and spacial steel structures. In this paper, the objective function is the weight of steel structures and the constraints are the design limits defined by design and buckling strengths, displacements and thicknesses. The design variables are dimensions and coordinates of steel sections. Design examples are given to show the applicability of the discrete optimum design program of this paper.

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Reliability and Safety Analysis of Structure System of Retaining Walls (옹벽구조시스템의 신뢰성 및 안전도 해석)

  • Jung, Chul-Won;Yun, Boung-Jo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.2 no.3
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    • pp.223-234
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    • 1998
  • In this study, an attempt is made to apply the concept of fuzzy-bayesian theory to the integrity assessment of structure system, and uncertainty states are represented in terms of fuzzy sets which define several linguistic variables such as "very good", "good", "average", "poor", "very poor", etc. Especially, the concept of fuzzy conditional probability aids to derive a new reliability analysis which includes the subjective assessment of engineers without introducing any additional correction factors. The fuzzy concept are also used as reliability indexes for the condition assessment based on the proposed models, the proposed fuzzy theory-based approach with the results of PEM and AFOSM are applied to retaining wall.

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Minimization of Membership Function with Fuzzy Control (펴지 제어기의 소속함수 최소화에 관한 연구)

  • Joo, Han-Jo;Park, Seung-Hun;Hong, Dea-Sung;Yim, Wha-Yoeng
    • Proceedings of the KIEE Conference
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    • 2003.11c
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    • pp.968-970
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    • 2003
  • Fuzzy Controller is a system that displays a person's thoughts using membership function and IF-THEN rules. With the help of specialists' knowledge, rule bases can be explained in easy language. Furthermore Fuzzy Controller has strong resistance against turbulence. Its performance is especially prominent when targets cannot be measured in mathematic methods because the fuzzy controller can measure the output using only the relations between the input and output. But Fuzzy System has a problem that is calculation speed. I suggest you a theory to solve it. I applied a theory to inverted pendulum. Because it is represent of nonlinear system.

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