• Title, Summary, Keyword: linguistic variable

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Algorithmic approach for handling linguistic values (언어 값을 다루기 위한 알고리즘적인 접근법)

  • Choi Dae Young
    • The KIPS Transactions:PartB
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    • v.12B no.2
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    • pp.203-208
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    • 2005
  • We propose an algorithmic approach for handling linguistic values defined in the same linguistic variable. Using the proposed approach, we can explicitly capture the differences of individuals' subjectivity with respect to linguistic values defined in the same linguistic variable. The proposed approach can be employed as a useful tool for discovering hidden relationship among linguistic values defined in the same linguistic variable. Consequently, it provides a basis for improving the precision of knowledge acquisition in the development of fuzzy systems including fuzzy expert systems, fuzzy decision tree, fuzzy cognitive map, ok. In this paper, we apply the proposed approach to a collective linguistic assessment among multiple experts.

An approach based on the LOWHM and induced LOWHM operators to group decision making under linguistic information

  • Park, Jin-Han;Lee, Bu-Young;Son, Mi-Jung
    • Journal of Korean Institute of Intelligent Systems
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    • v.20 no.2
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    • pp.285-291
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    • 2010
  • In this paper, we propose an induced linguistic ordered weighted harmonic mean(ILOWHM) operator. The ILOWHM operator is more general type of aggregation operator, which is based on the LHM and LOWHM operators. Based on the LOWHM and ILOWHM operator, we develop an approach to group decision making with linguistic preference relations. Finally, an application of the approach to group decision making problem with linguistic preference relations is pointed out.

A Study on the Knowledge Representation of Linguistic Variable Based on Fuzzy Logic (퍼지로직에 기반한 언어변수의 지식표현에 관한 연구)

  • 김형수;김홍기;김주진;이상부
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • pp.137-140
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    • 1996
  • In order to solve the specific problems in system, the implementing of knowledge base suitable to the system architecture has to be expressed and leads to the resoning of the new facts. Not only the simple knowledge based on the bivalent logic but also the representation and acqusition of knowledge related to vague and imprecise linguistic variable is necessary to the knowledge in the real world,i.e the knowledge of which facts and rules are composed. In this point of view, this survey implements the inference and retrieval of the fuzzy linguistic variables so that it can process the ambiguous information which appears the imprecision of the linguistic boundary.

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The Design of Student Module for Web-Based Instruction System using Fuzzy Theory (웹기반 교육 시스템에서 퍼지이론을 이용한 학습자 모듈의 설계)

  • 백영태;서대우;왕창종
    • Journal of the Korea Industrial Information Systems Research
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    • v.6 no.3
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    • pp.35-43
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    • 2001
  • This thesis proposes a diagnostic formula for student's responses based on linguistic variable concept of fuzzy that makes domain expert to input the kernel elementeasily that constructs domain independent student module. And the domain expert can construct the rule with linguistic variable that is used to inference student's recognition state. This study designs a student module that can inference student's recognition state using this rule represented by linguistic variable.

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Fuzzy Linguistic Variable Based Approach for Safety Assessment of Human Body in ELF Electromagnetic Field Considering Power System States (계통상태를 고려한 ELF 전자계의 인체안전평가를 위한 퍼지언어변수 접근법)

  • 김상철;김두현;고은영
    • Journal of the Korean Society of Safety
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    • v.12 no.2
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    • pp.70-79
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    • 1997
  • This paper presents a study on the fuzzy linguistic variable based approach for safety assessment of human body in ELF electromagnetic field considering power system states. To cope with the demand in modern industry, the power system becomes larger in scale, higher in voltage. The advent of high voltage system has increased the relative importance of field effects. The analysis of ELF electromagnetic field based on Quasi-Static Method is introduced while the power system is included to model the expected and/or unexpected uncertainty caused by the load fluctuation and parameter changes. In order to analyze the power system, Monte Carlo simulation method and contingency analysis method are adopted in normal state and alert state, respectively. In the safety assessment of human body, the approach based on fuzzy linguistic variable is employed to overcome the shortcomings resulting from a crisp set concept. The suggested scheme is applied to a sample system(modified IEEE 14 bus system) to validate the usefulness.

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An approach based on the generalized ILOWHM operators to group decision making

  • Park, Jin-Han;Park, Yong-Beom;Lee, Bu-Young;Son, Mi-Jung
    • Journal of Korean Institute of Intelligent Systems
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    • v.20 no.3
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    • pp.434-440
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    • 2010
  • In this paper, we define generalized induced linguistic aggregation operator called generalized induced linguistic ordered weighted harmonic mean(GILOWHM) operator. Each object processed by this operator consists of three components, where the first component represents the importance degree or character of the second component, and the second component isused to induce an ordering, through the first component, over the third components which are linguistic variables and then aggregated. It is shown that the induced linguistic ordered weighted harmonic mean(ILOWHM) operator and linguistic ordered weighted harmonic mean(LOWHM) operator are the special cases of the GILOWHM operator. Based on the GILOWHM and LWHM operators, we develop an approach to group decision making with linguistic preference relations. Finally, a numerical example is used to illustrate the applicability of the proposed approach.

Calculation Correctio Factor of Bridge Capacity using Fuzzy Sets Theory (퍼지를 이용한 교량 안전도평가의 보정계수 산정)

  • 조원신;박기태;김상효;황학주
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.240-244
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    • 1992
  • The values of a linguistic variable are words, phrases, or sentences in a given language. For example, structural damage can be considered as linguistic variable with values such a 'severely damaged', 'moderately damaged', which are meaningful classifications but not clearly defined, This paper is to evaluate reasonably the correction factor of bridge capacity with the aid of fuzzy sets theory. By using the above mentioned fuzzy measure, the concept of fuzzy integral and linear membership function can be defined. It is concluded that the fuzzy sets theory cam be applied to determine reasonably the correction factor of bridge capacity.

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The Tuning Method on Consequence Membership Function of T-S Type FLC (T-S형 퍼지제어기의 후건부 멤버십함수 동조방법)

  • Choi, Han-Soo;Lee, Kyoung-Woong
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.3
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    • pp.264-268
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    • 2011
  • This paper presents a Takagi-Sugeno (T-S) type Fuzzy Logic Controller (FLC) with only 3 rules. The choice of parameters of FLC is very difficult job on design FLC. Therefore, the choice of appropriate linguistic variable is an important part of the design of fuzzy controller. However, since fuzzy controller is nonlinear, it is difficult to analyze mathematically the affection of the linguistic variable. So this choice is depend on the expert's experience and trial and error method. In this paper, we propose the method to choose the consequence linear equation's parameter of T-S type FLC. The parameters of consequence linear equations of FLC are tuned according to the system error that is the input of FLC. The full equation of T-S type FLC is presented and using this equation, the relation between output and parameters can represented. The parameters are tuned with gradient algorithm. The parameters are changed depending on output. The simulation results demonstrate the usefulness of this T-S type 3 rule fuzzy controller.

Risk Assessment using Fuzzy Linguistic Variables in Korean (한국어 퍼지 언어변수를 이용한 리스크 평가)

  • Lim, Hyeon-Kyo;Byun, Sanghun;Kim, Hyunjung
    • Journal of the Korean Society of Safety
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    • v.30 no.4
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    • pp.151-158
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    • 2015
  • Usually risk assessment is performed for the safety of diverse industries though, many kinds of risks cannot be analyzed effectively by using classical probability models due to lack of experience data and impreciseness of human decision making. For these reasons, fuzzy risk assessment utilizing subjective judgment and experience of skillful experts has been considered as a solution. In this study, to comprehend the relationship between conventional fuzzy theory and human conceptual images on risks, linguistic variables were reviewed with reference to fuzzy membership functions, especially in the Korean language. As interviewees, about a hundred people including students as well as safety engineers voluntarily participated. The research results showed that most people were in favor of adjective expressions decorated with adverbs rather than naive expressions such as "high" or "low", and that directly translated linguistic variables were not appropriate for the Korean people in risk assessment as far. Therefore, with consideration of the selection tendency by the Korean people in linguistic variables, it could be concluded that 5 level expressions would be most favorable for linguistic variables in risk assessments in Korea.

The Development of Fuzzy to Decide System Failure Rate (시스템 고장률 결정을 위한 Fuzzy Model)

  • 김병석;김정한
    • Journal of the Korean Society of Safety
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    • v.8 no.4
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    • pp.91-94
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    • 1993
  • The main purpose of this study was to develop fuzzy models in order to decide system failure rate in industrial accident prevention. The purposed linguistic approach uses the Zadeh's concept of a linguistic variable with value which are not number. The problem of measurement Is the assignment of numbers to reprresnt properties of the involved events, object, or situation. Thus, in this study, part standard compatibility function was used.

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