• 제목/요약/키워드: Fuzzy assessment

검색결과 256건 처리시간 0.033초

제천지역 전압변동에 따른 전자계에 대한 퍼지척도 가능성 평가 (Assessment of Fuzzy Measure Possibility for the Electromagnetic Field according to Voltage fluctuation of the Jechon Area)

  • 김상철
    • 한국안전학회지
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    • 제20권2호
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    • pp.50-55
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    • 2005
  • This Paper Presents assessment of fuzzy measure Possibility far the electromagnetic field according to voltage fluctuation of the Jechon Area. To cope with substantial electromagnetic analysis, the safety assessment were analyzed the double 154kV T/L, 345kV T/L, Jechon-Ichon Jechon-Youngju, respectively. As the results of case study, in case of 345kV T/L, the electric field value was 11.4927kV/m, magnetic field value was 0.4622G at the Point about 7m away from the line in severest case. Tn assessment of fuzzy measure Possibility for the electromagnetic field, this paper use probability of fuzzy and measure of fuzziness technique.

퍼지신경망을 이용한 철근콘크리트 교량의 손상도 평가 (Damage Assessment of RC Bridge Using Neural-Fuzzy System)

  • 성영준;김기봉
    • 한국구조물진단유지관리공학회 논문집
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    • 제3권4호
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    • pp.129-137
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    • 1999
  • Assessment of structural damage is a complex subject imbued with uncertainty and vagueness. This complexity arises from the use of subjective opinion and imprecise numerical data. Recently several active researches have been performed using new methods such as neural network approach or on-line damage detection. In this paper, Damage assessment (diagnosis) of the concrete bridges is studied by a new approach utilizing a neural fuzzy system that combined a neural network and a fuzzy logic. By applying this system to actual in-service bridges, it has been verified that the neural fuzzy method is effective for the bridge diagnosis.

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돈육 생산공정에서의 정량적 위해 평가에 fuzzy 연산의 적용 (Application of Fuzzy Math Simulation to Quantitative Risk Assessment in Pork Production)

  • 임명남;이승주
    • 한국식품과학회지
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    • 제38권4호
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    • pp.589-593
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    • 2006
  • 돈육 가공 공정에 대한 QRA에 Monte Carlo simulation이 적용된 바 있는데, 새로운 방법으로 fuzzy 연산을 적용하여 Monte Carlo simulation과 비교 분석하였다. Carcass단계에 대한 오염 예측치인 fuzzy 값과 Monte Carlo simulation 확률분포 값의 기술통계량인 평균값은 각각 -4.393 log $CFU/cm^2$, -4.589 log $CFU/cm^2$ 로 나타났으며, processing 단계에서는 -4.185 log $CFU/cm^2$, -4.466 log $CFU/cm^2$으로 두 가지 접근 방법들이 비슷한 경향을 보였다. Fuzzy 값은 Monte Carlo simulation 확률분포 값을 포함하는 것으로 나타났다. 한편 최근 국내에서는 위해 평가에 대한 연구가 많이 이루어지고 있는데 대부분 데이터 분석은 Monte Carlo simulation에만 의존하고 있고, 다른 접근 방법에 대한 연구는 미진한 실정이다. 따라서 본 연구는 위해 평가를 위한 방법적 도구들을 개발하는데 새로운 접근 방향을 제시하였다 또한 향후 fuzzy 연산법은 데이터가 불충분한 위해 평가의 초기 단계에서 유용하게 사용될 수 있는 방법이 될 것이다.

퍼지공정을 이용한 차량용 에어크리너의 DFDA (Disassemblity Assesment of Aircleaner in Passenger-vehicle by Fuzzy)

  • 진정선
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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    • pp.57-62
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    • 1999
  • A disassembility assessment has mostly depend on the subjective decision making from the qualitative element. It is not useful in the practical assessement because it is not specified. The purpose of this paper is an assessmet based on Fuzzy-study-rule. This rule is definitely modified fromnon-fuzzy language of qualitative element. The new assessment method of design for disassembility assessment(DFDA) is practical to introduce the fuzzy number as the conversion of quantitative element from qualitative. It is appled to air-cleaner of passenger-vehicle for the usefulness.

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BOX-AND-ELLIPSE-BASED NEURO-FUZZY APPROACH FOR BRIDGE COATING ASSESSMENT

  • Po-Han Chen;Ya-Ching Yang;Luh-Maan Chang
    • 국제학술발표논문집
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    • The 3th International Conference on Construction Engineering and Project Management
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    • pp.257-262
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    • 2009
  • Image processing has been utilized for assessment of infrastructure surface coating conditions for years. However, there is no robust method to overcome the non-uniform illumination problem to date. Therefore, this paper aims to deal with non-uniform illumination problems for bridge coating assessment and to achieve automated rust intensity recognition. This paper starts with selection of the best color configuration for non-uniformly illuminated rust image segmentation. The adaptive-network-based fuzzy inference system (ANFIS) is adopted as the framework to develop the new model, the box-and-ellipse-based neuro-fuzzy approach (BENFA). Finally, the performance of BENFA is compared to the Fuzzy C-Means (FCM) method, which is often used in image recognition, to show the advantage and robustness of BENFA.

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Cash flow Forecasting in Construction Industry Using Soft Computing Approach

  • Kumar, V.S.S.;Venugopal, M.;Vikram, B.
    • 국제학술발표논문집
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    • The 5th International Conference on Construction Engineering and Project Management
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    • pp.502-506
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    • 2013
  • The cash flow forecasting is normally done by contractors in construction industry at early stages of the project for contractual decisions. The decision making in such situations involve uncertainty about future cash flows and assessment of working capital requirements gains more importance in projects constrained by cash. The traditional approach to assess the working capital requirements is deterministic in and neglects the uncertainty. This paper presents an alternate approach to assessment of working capital requirements for contractor based on fuzzy set theory by considering the uncertainty and ambiguity involved at payment periods. Statistical methods are used to deal with the uncertainty for working capital curves. Membership functions of the fuzzy sets are developed based on these statistical measures. Advantage of fuzzy peak working capital requirements is demonstrated using peak working capital requirements curves. Fuzzy peak working capital requirements curves are compared with deterministic curves and the results are analyzed. Fuzzy weighted average methodology is proposed for the assessment of peak working capital requirements.

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우리나라 홍수 취약성 평가를 위한 Fuzzy TOPSIS 접근법 (Fuzzy TOPSIS Approach to Flood Vulnerability Assessment in Korea)

  • 김영규;정은성;이길성
    • 한국수자원학회논문집
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    • 제45권9호
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    • pp.901-913
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    • 2012
  • 본 연구는 불확실성을 고려하여 홍수 취약성 평가를 정량화하기 위한 새로운 방법을 제시하였다. 현실 세계로부터 얻는 많은 정보들은 불확실성을 가지고 있으므로 본 연구는 우리나라의 공간적 홍수 취약성을 산정하기 위해 Fuzzy TOPSIS기법을 사용하였다. 또한 Fuzzy TOPSIS의 결과를 TOPSIS 및 가중합계법을 적용한 결과와 비교하였다. 그 결과 일부지역의 취약성 순위가 큰 폭으로 역전되는 현상을 보였다. Spearman 순위 상관분석을 실시한 결과 TOPSIS와 가중합계법의 순위는 높은 일치성을 보였으나 Fuzzy TOPSIS의 순위와는 상당히 일치하지 않은 결과를 나타냈다. 즉, Fuzzy 개념을 반영하여 지역별 취약성을 산정할 경우 우선순위의 변동이 크게 발생할 수 있으므로 본 연구에서 제시한 모형도 하나의 취약성 평가의 방법이 될 수 있다.

터널 콘크리트 라이닝의 상태평가를 위한 퍼지추론기법 연구 (A Study on Fuzzy Logic Method for the Assessment of Tunnel Concrete Lining)

  • 이성원;조만섭;이광호;이석원;배규진;안영기
    • 터널과지하공간
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    • 제9권4호
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    • pp.337-349
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    • 1999
  • 터널의 안전진단시 관련기술자들이 겪는 어려움은 터널구조물의 안전성에 미치는 다양한 영 향인자 만큼이나 많다. 때문에 안전진단의 최종결과로 대별되는 상태평가와 안전성평가에서는 터널 안전진단 전문가 또는 전문기관에서 조차 객관적인 결과을 얻어내기가 어렵다. 본 연구에서는 애매함이 산재해 있는 터널구조물의 안전진단시 겪는 여러 가지 문제들 중 콘크리트 라이닝의 상태평가를 보다 정량적이고 객관적으로 수행하기 위하여 인공지능기법 중 진단, 제어, 의사 결정 등에 효과적인 방법으로 알려진 퍼지 추론 방법을 이용하여 해결해보고자 시도하였다. 본 연구를 통해 퍼지추론을 이용한 평가시 스템인 T-FLAS를 개발하고, 기존의 터널 안전진단 결과와의 비교를 통하여, 터널 안전진단에 퍼지추론 적용 가능성을 확인 하였다.

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삼각퍼지수를 활용한 지역환경 평기지표 순위 결정 - 생태계를 중심으로 - (Rank Decision on Regional Environment Assessment Indicators Using Triangular Fuzzy Number - Focused on Ecosystem -)

  • 유주한;정성관;박경훈;김경태
    • 환경영향평가
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    • 제15권6호
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    • pp.395-406
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    • 2006
  • This study was carried out to offer the systematical and scientific method of regional environment conservation by deciding the rank using fuzzy theory, and try to find the methodology to accurately accomplished the regional environment assessment for sound land conservation. The results were as follows. To transform the Likert's scale granted to assessment indicators into the type of triangular fuzzy number (a, b, c), there was conversion to each minimum (a), median (b), and maximum (c) in applying membership function. We used the center of gravity and eigenvalue leading to the rank. In the sequential analysis of rank-based test of assessment indicators by triangular fuzzy number, the result proclaimed that ranking of the indicators was, in the biotic field, in the order of 'dominance', 'sociality', 'coverage' and in the abiotic one, 'soil pH', 'T-N', 'soil property', and in the qualitative one, 'impact rating class', 'hemeroby degree', 'land use pattern', and in the functional one, 'protection of water resource', 'offer of recreation', 'protection of soil erosion'. Therefore, there was a difference between subjective rank from human and the rank from triangular fuzzy number. In other words, the scientific rank decision would be not so much being subjective and biased as dealing with human thoughts mathematically by triangular fuzzy number.

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

  • 임현교;변상훈;김현정
    • 한국안전학회지
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    • 제30권4호
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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.