• Journal of Radiation Protection and Research
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• v.29 no.2
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• pp.129-139
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• 2004

Recently, much attentions are paid to the risk associated with increased uses of medium size radiation sources in medical and industrial fields. In this study, radiation risks to the worker and to the general public due to $^{99m}Tc$ generator were assessed for both normal and accident conditions. Based on the event tree technique, exposure scenarios for various situations were derived. Uncertainty analysis based on the Monte-Carlo technique was applied to the risk assessment for workers and members of the public in the vicinity of the work place. In addition, sensitivity analysis was performed on each of the five independent input parameters to identify importance of the parameters with respect to the resulting risk. Because the frequencies of normal tasks are fat higher than those of accidents, the total risk associated with normal tasks were higher than the accident risk. The annual dose due to normal tasks were $0.6mSv\;y^{-1}$ for workers and $0.014mSv\;y^{-1}$ for public, while in accident conditions $3.96mSv\;y^{-1}\;and\;0.0016mSv\;y^{-1}$, respectively. Uncertainty range of accident risk was higher by 10 times than that of normal risk. Sensitivity analysis revealed that source strength, working distance and working time were crucial factors affecting risk. This risk analysis methodology and its results will contribute to establishment of risk-informed regulation for medium and large radioactive sources.

• Proceedings of the KSRS Conference
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• 2007.03a
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• pp.296-300
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• 2007

본 연구에서는 강원도 정선지역 및 삼척지역의 폐탄광 지역에서 관측된 지반침하지역의 공간자료와 각종 지반침하 관련요인을 분석하여, 지질학적구조와 지역적 특성이 상이한 지역에서 지반침하에 직접적인 영향을 주는 공통요인을 찾아내고자 하였다. 연구지역의 지반침하 관련요인들에 대해 GIS(Geographic Information System)를 이용하여 래스터 데이터베이스를 구축하고 모든 요인을 이용하여 분석한 위험지역과 하나의 요인씩 제거하며 분석한 위험지역을 비교하는 민감도 분석 (Sensitivity analysis)을 통해 지반침하와 연관성이 높은 요인을 추출하였다. 민감도 분석은 서로 다른 두 지역에 대해 수행하여 그 결과를 비교하였으며, 갱으로부터의 수평거리，RMR(Rock Mass Rating), 지하수 심도가 지반침하에 영향을 주는 공통요인으로 분석되었다. 본 연구결과, 폐탄광지역의 지반침하에 공통적으로 영향을 끼치는 주 요인을 구할 수 있었으며, 타 지역에서 지반침하 예측시 기존 연구에서 사용한 요인들의 데이터를 전부 구하지 못하는 경우에도 최소한의 필요한 요인을 정할 수 있으며 지반침하 예측의 효율성을 높일 수 있을 것이라 기대된다.

• 한국지구물리탐사학회:학술대회논문집
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• 2006.06a
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• pp.247-252
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• 2006

This study analysed the sensitivity of the attenuation functions for the seismic hazard estimation. For the seismic hazard estimation, this study used HAZUS software, which is developed originally by FEMA(USA). The scenario earthquake ($M_w=6.0$) is located the Hongsung area, where one of the recent macro earthquakes occurred in 1978. The area for seismic hazard estimation is assumed to be Boryung city in Choongnam-do. Three attenuation functions were applied for the sensitivity analysis. The results show that the attenuation functions have much influences on the seismic hazard on the various types of buildings. Therefore the attenuation function is very important factor for the seismic hazard estimation.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.122-122
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• 2019

가뭄위험도(Drought Risk)는 위해성(Hazard), 취약성(Vulnerability), 민감도(Sensitivity) 및 적응능력(Adaptive Capacity) 등 여러 가지의 지표를 활용하여 평가가 가능하다. 가용한 자료와 분석기법에 따라서 위해성과 취약성만으로도 평가가 가능하며, 유역내의 가용한 수자원인프라에 의한 적응능력을 포함하여 평가할 수도 있다. 본 연구에서는 미래 가뭄위험도를 평가하기 위하여 기후학적 인자인 가뭄 위해성과 사회 경제적 인자인 취약성 인자 그리고 유역내의 수자원 인프라시설(용수공급 시설)에 의한 적응능력과 관련된 지표를 조합하였다. 특히, 물수요와 공급가능량을 고려한 물수지분석을 통하여 미래 용수공급 안정성을 평가하였으며 다양한 기후변화 시나리오 기반 가뭄 위해성 인자를 Rating 기법을 활용하여 산정하였으며, 취약성의 경우 인구밀도, 농경지 면적 등의 민감도와 적응능력을 동시에 고려할 수 있는 용수 부족량을 시나리오별로 산정하였다. 본 연구를 통하여 도출된 한반도의 미래 가뭄위험도 평가 결과는 유역별 가뭄대책을 수립하기 위한 기초자료로 활용될 수 있을 것으로 판단된다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.5
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• pp.1753-1763
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• 2013

In the design phase of sea-crossing bridge projects, ship collision problem is mostly participated in decision of substructure section and it would be performed by risk assessment and impact simulations. Ship collision risk is assessed by probability model which is similar to method II of Guide Specification and Commentary for Vessel Collision Design of Highway Bridge(AASHTO, 2009). However, several factors used in the applicable code are limited to inland waterways or have many local characteristics. Accordingly, it should be needed judgement of engineer or referred to related criteria, research finding. In this study risk assessment for In-cheon bridge and review of existing substructure's impact risk and resistance capacity are performed using the 2010's ship passage data. And then consideration regarding to presumption and applied instance of factors needed for risk assessment and related research findings are performed on the basis of AASHTO Guide's Method. As a result of study, adequate variable region of factors needed for risk assessment is defined and sensitivity analysis for appropriate region is performed. Consequently, factors that should be applied carefully or needed for direct analysis of local data are confirmed. This research could be fundamental material to risk assessment related to design for sea-crossing bridge taken into account ship collision.

• Life and Agrochemicals
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• v.26 no.5 s.208
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• pp.37-39
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• 2005

• Journal of the Korean Society for Railway
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• v.12 no.2
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• pp.190-198
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• 2009

This study shows the developing process of the risk assessment models for railway casualty accidents. To evaluate the risks of these accidents, the hazardous events and the hazardous factors were identified by the review of the accident history and engineering interpretation of the accident behavior. The frequency of each hazardous event was evaluated from the historical accident data and structured expert judgments by using the Fault Tree Analysis (FTA) technique. In addition, to assess the severity of each hazardous event, the ETA (Event Tree Analysis) technique and other safety techniques were applied. The risk assessment models developed can be effectively utilized in defining the risk reduction measures in connection with the option analysis.

• Nuclear Engineering and Technology
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• v.19 no.4
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• pp.249-265
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• 1987

For the probabilistic risk assessment of the high level radioactive waste repository, some methods have been proposed up to now. Since the system has highly uncertain input parameters, the evaluated risk for some input parameter values has high uncertainty. In this paper, methods of uncertainty and sensitivity analysis are devised to analyse systematically these factors and applied to a probabilistic risk assessment model of the high level waste repository, The statistical package SPUSA developed through this study can be used for any other fields, e.g., statistical thermal margin analysis, source term uncertainty analysis, etc.

• Korean Journal of Environmental Biology
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• v.32 no.1
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• pp.68-74
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• 2014

Scientific study has investigated the body condition differences by habitat characteristics in larvae Korea salamander (Hynobius leechii) from March to April in 2012. To examine the sensitivity of external environment (predation risk), we divided two groups according to habitat characteristic; 1) Permanent pond and 2) Temporary pond. Howere, each larva was measured by head width at the level of the eye (HWE), largest head width (LHW) and snout-vent length, and we calculated the ratio of the head size by dividing HWE/LHW. As a result, larvae were larger in permanent pond group, had a faster growth rate than in temporary pond group. When exposed to the predator, larvae in permanent pond were smaller HWE/LHW than larvae in permanent pond. Therefore, these results indicate larvae in temporary pond more sensitive to the external environment.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.175-177
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• 2008

본 논문에서는 I-PIU를 통해 등기화된 데이터를 취득 이용하여 실시간 계통 감시는 물론 광역정전방지에 대한 방법을 제안하고 있다. 또한 민감도 지수(Sensitivity Factor)를 이용한 취약도 지수(Vulnerability Index)와 실시간 데이터를 이용한 거리계전기 동작을 예측 알고리즘을 적용하여 실시간 계통의 상황감시는 물론 계통의 위험 정도를 미리 알리는 거리 계전기 모니터링 시스템을 설계하였다 이는 운영자로 하여금 개통의 위험 요소를 적절한 조치를 취해 제거함으로써 치명적인 광역 정전 사태의 방지와 효율적 계통관리를 기대 할 수 있다.