• 한국지반환경공학회 논문집
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• 제17권6호
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• pp.13-21
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• 2016

기존의 토사재해 위험지역 예측은 토질특성과 경사만으로 분석되기 때문에 지역적 특징이 반영되어 있지 않다. 따라서 보다 합리적인 위험지 예측 분석을 위하여 해당지역의 특징을 반영한 토사재해 위험지 예측을 할 필요가 있다. 토사재해 위험지의 특징 중 하나인 수목의 뿌리는 토사 내 점착력을 증가시키는 작용을 하는 것으로 연구되어 왔으며, 수목의 종류에 따라 그 영향이 다른 것으로 알려져 있다. 또한, 지역에 따라 수목의 밀집 정도(수관밀도)가 다양하기 때문에 실제 수목의 분포를 고려하여 토사재해 위험지역 예측을 한다면 보다 합리적인 위험지 예측이 가능할 것이다. 본 연구에서는 세종시 괴화산 일대를 중심으로 수목의 수관밀도를 고려한 뿌리점착력을 사용하여 토사재해 위험지역 예측을 하였으며, 뿌리점착력을 적용하지 않은 토사재해 위험지역 예측 결과와 비교하였다.

• 한국안전학회지
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• 제10권1호
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• pp.56-63
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• 1995

Two methods of the numerical method of CPQRA(Chemical Process Quantitative Risk Analysis) and the manual method of IAEA(International Atomic Energy Agency) were used to estimate the individual risk and societal risk around the chemical plant. Where, the CPQRA is introduced to verify the theoritical background of the manual of international atomic energy agency. The Gaussian plume model which has a weather stability class D with velocity of 5m/s was applied to calculate dispersion of hazard material. Also, 8-point method was employed to the effects of accidents for wind distribution. Furthermore, historical record, FTA(Fault Tree Analysis) and ETA(Event Tree Analysis) were used to estimate the probability or frequency of accidents. Eventually, the individual risk shows isorisk contour and the societal risk shows F-N curve around hazard facility, especially in chemical plants. Caulculated results, which both individual and societal risk, by using IAEA manual show simillar results to those of calculation by numerical method of CPQRA.

• Journal of Advanced Research in Ocean Engineering
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• 제3권3호
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• pp.125-135
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• 2017

The paper considers the practical application of the FMEA(Failure Mode and Effect Analysis) method to assess the operational reliability of the LNG(Liquefied Natural Gas) transfer system, which is a potential problem for the connection between the LNG FPSO and LNG carrier. Hazard Identification (HAZID) and Hazard operability (HAZOP) are applied to identify the risks and hazards during the operation of LNG transfer system. The approach is performed for the FMEA to assess the reliability based on the detection of defects typical to LNG transfer system. FTA and FMEA associated with a probabilistic risk database to the operation scenarios are applied to assess the risk. After providing an outline of the safety assessment procedure for the operational problems of system, safety assessment example is presented, providing details on the fault tree of operational accident, safety assessment, and risk measures.

• 대한토목학회논문집
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• 제28권1B호
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• pp.33-40
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• 2008

우리나라는 6월부터 9월까지의 우기에 강우가 집중 발생하는 기상특성으로 인해 자연재해의 95% 이상이 집중호우와 태풍에 의한 풍수해로 집계되고 있을 만큼 홍수피해에 취약하며, 오래전부터 홍수방어에 대한 구조적 대책이 시행되어왔다. 본 연구의 목적은 의사결정기법중의 하나인 의사결정나무를 이용하여 유역내 홍수방어를 위한 기본적인 후보대안을 제시하는데 있다. 이러한 후보대안은 유역이 가지고 있는 치수적 기능을 최대한 살리고 상 하류의 유기적인 홍수방어기능을 효율적으로 증대시키는 다수의 조합으로 제시되었다. 또한 본 연구에서는 유역종합치수계획 수립시 적용가능한 홍수방어 대안 조합 지침을 제시하였다.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2000년도 춘계학술대회
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• pp.207-215
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• 2000

This study deals with the application of knowledge-engineering and a methodology for the assessment & measurement of reliability, availability, maintainability, and safety of industrial systems using fault-tree representation. A fuzzy methodology for fault-tree evaluation seems to be an alternative solution to overcome the drawbacks of the conventional approach(insufficient information concerning the relative frequences of hazard events). To improve the quality of results, the membership functions must be approximated based on heuristic considerations. The purpose of this Is to describe the knowlwdge engineering approach, directed to integrate the various sources of knowledge involved in a FTA.

• 대한안전경영과학회지
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• 제2권2호
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• pp.1-10
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• 2000

This study deals with the application of knowledge engineering and a methodology for the assessment and measurement of reliability, availability, maintainability, and safety of industrial systems using fault-tree representation. A fuzzy methodology for fault-tree evaluation seems to be an alternative solution to overcome the drawbacks of the conventional approach (insufficient information concerning the relative frequence of hazard events). To improve the quality of results, the membership functions must be approximated based on heuristic considerations. The purpose of this study is to describe the knowledge engineering approach, directed to integrate the various sources of knowledge involved in a FTA.

• Earthquakes and Structures
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• 제10권2호
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• pp.389-408
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• 2016

Recently, seismic hazard analysis has become a very significant issue. New systems and available data have been also developed that could help scientists to explain the earthquakes phenomena and its physics. Scientists have begun to accept the role of uncertainty in earthquake issues and seismic hazard analysis. However, handling the existing uncertainty is still an important problem and lack of data causes difficulties in precisely quantifying uncertainty. Ground Motion Prediction Equation (GMPE) values are usually obtained in a statistical method: regression analysis. Each of these GMPEs uses the preliminary data of the selected earthquake. In this paper, a new fuzzy method was proposed to select suitable GMPE at every intensity (earthquake magnitude) and distance (site distance to fault) according to preliminary data aggregation in their area using ${\alpha}$ cut. The results showed that the use of this method as a GMPE could make a significant difference in probabilistic seismic hazard analysis (PSHA) results instead of selecting one equation or using logic tree. Also, a practical example of this new method was described in Iran as one of the world's earthquake-prone areas.

• Structural Engineering and Mechanics
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• 제32권4호
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• pp.563-581
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• 2009

In this paper, the peak horizontal ground acceleration over the bedrock (PGA) is calculated by a probabilistic seismic hazard assessment (PSHA). For this reason, at first, all the occurred earthquakes in a radius of 200 km of Sanandaj city have been gathered. After elimination of the aftershocks and foreshocks, the main earthquakes were taken into consideration to calculate the seismic parameters (SP) by Kijko (2000) method. The seismotectonic model of the considered region and the seismic sources of the region have been modeled. In this research, Sanandaj and its vicinity has been meshed as an 8 (vertical lines) * 10 (horizontal lines) and the PGA is calculated for each point of the mesh using the logic tree method and the five attenuation relationships (AR) with different weighted coefficient. These calculations have been performed by the Poisson distribution of four hazard levels. Then by using it, four regional maps of the seismic hazard regions have been provided for Sanandaj and its vicinity. The results show that the maximum and minimum value of PGA for the return periods of 75, 225, 475, 2475 years are (0.114, 0.074) (0.157, 0.101), (0.189, 0.121) and (0.266, 0.170), respectively.

• 대한안전경영과학회지
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• 제4권1호
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• pp.37-47
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• 2002

Risk analysis is a formal deductive procedure for determining combinations of component failures and human errors that could result in the occurrence of specified undesired events at the system level. This method can be used to analyze the vast majority of industrial system reliability problems. This study deals with the application of knowledge-engineering and a methodology for the assessment ＆ measurement of reliability, availability, maintainability, and safety of industrial systems using FTA(fault tree analysis), A fuzzy methodology for fault-tree evaluation seems to be an alternative solution to overcome the drawbacks of the conventional approach (insufficient Information concerning the relative frequencies of hazard events). To improve the quality of results, the membership functions must be approximated based on heuristic considerations, The purpose of this study is to describe the knowledge engineering approach, directed to integrate the various sources of knowledge involved in a FTA.

• 한국지리정보학회지
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• 제17권4호
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• pp.200-214
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• 2014

Technology Planning은 기술의 급격한 발전 쇠퇴와 함께 중대해지고 있다. Technology Roadmapping은 Technology Planning을 위한 기술로서, 어떤 기술을 어떤 시간 내에서 추구해야 할지를 선택하는 도구이기도 하며 불확실한 미래에 대한 기술전략으로서 핵심기술을 선행 확보하고 조직간 목표와 전략을 공유할 수 있는 방법론을 제공한다. 따라서 과제의 계획 단계에서 기술 트리는 매우 유용한 도구라 할 수 있다. 본 연구에서는 국내외 기술트리 활용 사례를 분석하고, 향후 융합형 포털 시스템 구축을 위한 연구 수행체계와 요구되는 기반 확보를 위한 방안을 도출하고자 하였다. 수재해 정보플랫폼에서 목표로 하는 6개의 주요 시스템은 기초정보제공시스템, 분석정보제공시스템, 수재해주제도제공시스템, 국가재난정보제공시스템, 수재해증강현실시스템 및 오픈정보플랫폼시스템이다. 각 목표 시스템에서 필요로 하는 기능에 대응하는 일반적이고 표준화된 핵심 기술을 브레인스토밍을 통해 도출하고, 기술 분야에 따라 분류 및 그룹화 하여 기술트리를 도출하였다.