퍼지 다기준 위험평가 방법의 개발 = Development of a fuzzy multi-criteria risk assessment method

다국어 초록 (Multilingual Abstract)

For any hazardous operation or risky project to be carried out safely and economically, it is of the utmost importance to formulate proper risk management policies based on the rational assessment of the risk levels of various potential hazards.
In a typical risk assessment process, the three risk factors, the likelihood of occurrence, the exposure, and the severity of consequences are first determined by verbal descriptions such as 'quite possible' and 'practically impossible', and then they are transformed into numerical values using a proper scale. However, when experts are asked to assess a numerical level of each risk factor, they might think the verbal descriptions given are vague and/or imprecise. Direct use of verbal descriptions, therefore, may results in considerable difficulties in evaluating the risk factors correctly. In such cases, it would be reasonable to follow the fuzzy set approach using fuzzy linguistic values, instead of conventional verbal descriptions, in order to determine an overall risk level more precisely.
In this study, proposed is a risk assessment method utilizing fuzzy multi-criteria decision models, where not only the levels of the three risk factors of each potential hazard but also its relative importance are expressed in terms of fuzzy linguistic values. The method also allows some flexibility for the future users in the sense that, first, the relative importance weights for the three risk factors can be adjusted according to the nature of projects or systems and, second, the users have the choice between the two types of risk assessment results, that is, the assessed risk levels or the ranks of the risk situations.
A numerical example for the proposed method is provided to illustrate the computational procedure.
To see how the suggested method describes well people's perceived risk level, we compared the risk values derived from the suggested method with the subjective risk evaluations for ten risky situations.
To enhance the applicability in Korea, new sets of fuzzy linguistic values written in Korean for the three risk factors and relative importance of each hazard are formulated. Then, five, seven, and nine-point scales are constructed from these sets through a questionnaire. An experiment using a questionnaire is also conducted to compare the relative performance of the three scales. The results indicate that the seven-point scale is preferable to the others considering ease and precision. For each fuzzy linguistic value in seven-point scales, a proper membership function is then developed.
To test the feasibility of the Proposed method, it was applied in two construction projects. The results were presented to the project manager and the risk analysts of the nm. Their response was that the assessed risk levels agreed with their ordinary beliefs and that the information could be advantageously used for safety planning and risk management of the project.

목차 (Table of Contents)

• 목차 = ⅰ
• 제1장 서론 = 1
• 1.1 연구의 필요성과 목적 = 1
• 1.2 연구의 방법과 구성체계 = 3
• 1.2.1 연구의 방법 = 3
• 1.2.2 연구의 구성체계 = 5
• 제2장 위험평가 방법의 일반적 고찰 = 6
• 2.1 시스템 위험분석방법 = 10
• 2.1.1 초기위험분석 = 10
• 2.1.2 고장모드 영향분석 = 11
• 2.1.3 Decision tree와 ETA = 11
• 2.1.4 THERP = 12
• 2.1.5 결함수 분석법 = 13
• 2.1.6 위험요소 및 운전성 검토 = 13
• 2.2 정성적 위험평가방법 = 15
• 2.3 위험평가를 위한 서술적 표현과 퍼지 언어변수 = 24
• 제3장 퍼지 다기준 위험평가 방법을 이용한 위험수준평가 = 34
• 3.1 제안된 퍼지 다기준 위험평가 방법 = 34
• 3.1.1 퍼지 집합과 퍼지수 = 36
• 3.1.2 언어변수와 퍼지 관계 = 40
• 3.1.3 퍼지 다기준 위험평가 방법 알고리즘 = 47
• 3.1.4 수치예 = 54
• 3.2 기존 방법과의 비교를 위한 설문분석 및 평가 = 59
• 3.2.1 설문구성 및 목적 = 59
• 3.2.2 설문분석 = 63
• 3.3 소결론 = 70
• 제4장 한글 퍼지 언어표현을 이용한 퍼지 다기준 위험평가방법의 개발 = 72
• 4.1 서론 = 72
• 4.2 위험요소의 한글 퍼지 언어 표현 = 75
• 4.2.1 각 위험요소에 대한 한글 퍼지 언어분류방식 = 75
• 4.2.2 합리적 한글 퍼지 언어 분류크기의 결정 = 82
• 4.2.3 한글과 영문 퍼지 언어표현 분류방식의 비교 = 85
• 4.2.4 위험요소의 세부수준과 위험치 사이의 소속함수 결정 = 87
• 4.3 수치예 = 93
• 4.4 소결론 = 96
• 제5장 사례분석 = 98
• 5.1 건설의 안정성 = 98
• 5.1.1 건설 프로젝트의 안전 = 98
• 5.1.2 건설 프로젝트의 특성 = 99
• 5.2 건설 프로젝트의 사례분석 = 101
• 5.3 분석결과 및 검토 = 104
• 제6장 결론 = 109
• 참고문헌 = 112
• ABSTRACT = 124
• 부록 = 127