• Nuclear Engineering and Technology
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• 제49권4호
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• pp.710-720
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• 2017

In Korea, many nuclear power plants operate at a single site based on geographical characteristics, but the population density near the sites is higher than that in other countries. Thus, multiunit accidents are a more important consideration than in other countries and should be addressed appropriately. Currently, there are many issues related to a multiunit probabilistic safety assessment (PSA). One of them is the quantification of a multiunit PSA model. A traditional PSA uses a Boolean manipulation of the fault tree in terms of the minimal cut set. However, such methods have some limitations when rare event approximations cannot be used effectively or a very small truncation limit should be applied to identify accident sequence combinations for a multiunit site. In particular, it is well known that seismic risk in terms of core damage frequency can be overestimated because there are many events that have a high failure probability. In this study, we propose a quantification method based on a Monte Carlo approach for a multiunit PSA model. This method can consider all possible accident sequence combinations in a multiunit site and calculate a more exact value for events that have a high failure probability. An example model for six identical units at a site was also developed and quantified to confirm the applicability of the proposed method.

• Environmental Analysis Health and Toxicology
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• 제25권3호
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• pp.207-214
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• 2010

Toxicity identification and quantification are important factors to evaluate the effect of industrial effluent on the aquatic environment. In order to measure the potential and real toxicity of mixed chemicals in the effluents, the biological method (i.e., WET test) should be used as well as chemical analysis method. In this study, we conducted WET test for various kinds of industrial effluents using aquatic organisms such as water flea (Daphnia magna), algae (Pseudokirchneriella subcapitata), fish (Oryzias latipes, Danio rerio), and microorganism (Vibrio fisheri). In addition, we carried out chemical analysis and TIE (Toxicity Identification Evaluation) for effluents in order to identify the substances causing toxicity. Among the 30 kinds of wastewater, S13 showed the highest eco-toxicity and $Ca^{2+}$ and $Cl^-$ ion were suspected as major compounds causing toxicity for aquatic organisms. In order to confirm these suspected compounds, various confirmation procedures need to be carried out.

• 한국수자원학회논문집
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• 제33권6호
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• pp.681-688
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• 2000

수해에 따른 피해확대를 방지하기 위해서는 지역주민의 피난행동양식의 분석 및 관련정보의 공개 등과 같은 제반 정보를 활용한 재해위기관리의 대책이 불가피하다. 본 연구에서는 수해의 대응대책 중 특히 인명보호의 차원에서 중요한 피난활동을 대상으로 실제 피난행동을 하기까지의 영향요인을 분석하였다. 피난행동을 규정하는 심리적인 영향요인에 대해서는 주민의 의식조사를 토대로 내.외적인 요인으로 분류하여 도출하였으며, 수량화(II) 이론을 이용하여 수해에 대한 주민의 의식 및 행동양식을 지리적.사회적 영향인자와 관련하여 분석하였다. 또한 GIS를 이용한 유역정보의 축적 및 활용을 통하여 유역주민이 재해에 대한 자주적인 판단능력을 고양함으로써 수해에 따른 피해를 최소화하는 방안에 대하여 고찰하였다.

• 한국안전학회지
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• 제29권1호
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• pp.1-6
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• 2014

With increasing number of citizen using subway stations everyday, safety, health and comfort of passengers and occupants became an important social issue. Considering the fact that various physical variables and pollutants are related to indoor air quality (IAQ) which may cause health problem, IAQ need to be closely monitored and controlled in multiple locations in subway stations. This study is a continuation of the previous studies and delay induced in wireless-wired network is experimentally evaluated and the risk involved is assessed. In doing that, a key parameter is identified to be the network delay in different network media. Application of information-theoretic measure to assess the risk in network delay is then discussed. The idea is based on the general principles of engineering design and their applications to quantification of uncertainty in network delay. Experimental results show that more risk is involved in wireless data communication. Efficient and fast conversion of transmission data in both LonWorks/IP server and ZL converter is also noted.

• 한국건축시공학회지
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• 제17권3호
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• pp.287-294
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• 2017

최근 건설프로젝트가 대형화 복잡화되어 감에 따라, 건설공사에서의 리스크 및 불확실성이 급증하고 있다. 증가하고 있는 건설 공사의 위험을 정량적으로 평가하고 관리 할 수 있는 모델 개발을 위해서는 위험 인자를 식별하고 위험인자의 발생 빈도와 심도를 계량화하는 연구가 우선되어야 한다. 이에 본 연구에서는 건설현장에서 발생한 사고 데이터를 기반으로 하여 위험요인의 확률분포 및 리스크 레벨별 위험의 발생 확률과 위험의 발생 빈도를 몬테카를로 기법을 통해 시뮬레이션하였다. 시뮬레이션을 통해 사고 원인의 확률 분포 및 사고 원인별 위험도를 분석하여 계량적 분석 결과를 도출하였다. 본 연구의 결과는 향후 정량적 위험관리모델 및 위험관리 연구를 위한 기초 자료가 될 것이다.

• 한국환경보건학회지
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• 제50권2호
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• pp.138-145
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• 2024

Background: Appropriateness issues have emerged regarding the non-application of hazardous substance safety standards for items classified as 'other textile products'. Objectives: Testing for formaldehyde (HCHO) and risk assessment were conducted on 'other textiles products' to provide reference data for promoting product safety policies. Methods: Testing was conducted on five items (102 products) classified as 'other textile products' according to relevant standards (textile products safety standards), and the risk of each product was assessed using the evaluation methodologies of the European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) and European Chemical Agency (ECHA). Results: Out of the 102 products tested, HCHO was detected above the quantification limit in five. Based on these results, the screening risk assessment indicated that three products exceeded the criteria. Upon reassessing the emission and transfer rates of products exceeding the criteria, it was confirmed that there were no instances of exceeding the criteria. Conclusions: Risk assessment results can be used as supporting data for non-application of hazardous substance standards. However, it is deemed necessary to transition towards a management approach based on risks in order to addressing emerging trends such as convergence/new products.

• 한국컴퓨터정보학회논문지
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• 제14권10호
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• pp.207-215
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• 2009

최근 도시화 율이 증가됨에 따라 발생되는 도시의 범죄 예방을 위하여 컴퓨터정보기술과 GIS 기술을 이용한 범죄 공간의 분석에 대한 연구가 활발하게 이루어지고 있다. 본 논문에서는 정적인 환경에서 도시공간정보에 포함된 지역특성을 이용하여 단위 셀별 우범 위험도를 계량화하여 래스터 형태의 확률 지도를 구성하였다. 지형적 특성에 의한 상대적 위험도, 시설물에 의한 상대적 위험도, 수목이나 하천에 의한 위험도 등을 기본으로 하여 위험도 확률 지도를 구축한다. 이를 통합한 위험도 확률 지도를 구할 때는 각각의 단위 위험도에 기후나 계절적 요인에 의해 가중치를 적용한 후 평균하게 된다. 또한 일회성 분석이 아닌 범죄 발생 상대적 위험지수의 패턴을 판독키로 하여 전체 위험도의 확률 지도를 생성하여 이후 발생하는 범죄의 유형을 계량화하는 확률지도에 추가적으로 적용하어 정적인 정보가 아닌 시간의 흐름에 따라 범죄 위험도 확률지도가 달라질 수 있는 모델과 시뮬레이션 하는 방법론을 제안하였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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• pp.45-46
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• 2019

Accident rate in domestic construction industry has been increased rapidly in every year. In particular, the rate of death has been shown very high compared with other industries. It means that safety activities performed by government is not effective in reducing the rate of accident. To solve these problems, the risk factors should be predicted in advance, controlled, monitored and managed from start of project to end of project. However, most studies have been conducted by using frequency of occurrence of accident and only listed the importance of risk. Therefore, the objective of this study is to provide basic material to develop risk quantifying model for human accidents on construction site in South Korea. In the future, it is expected to be used as a reference of study on developing safety mangement checklist in construction industry and model for forecasting accident.

• 자원리싸이클링
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• 제30권5호
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• pp.3-9
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• 2021

우리나라에서 연, 아연, 동, 주석, 니켈, 알루미늄 등의 베이스메탈의 수급구조는 양극화된 특성을 지니고 있다. 연, 아연, 동 등은 국내에 세계적 규모의 생산기업이 있는 반면, 주석, 니켈, 알루미늄 등은 국내 생산기업이 전무하거나, 생산량이 미비하여 내수량의 대부분을 수입에 의존하고 있다. 따라서 베이스메탈의 수입중단 또는 국내생산기업의 생산 중단 등의 공급중단에 따른 리스크에 대한 대비가 필요하다. 본 연구에서는 베이스메탈 6종(구리, 연, 아연, 알루미늄, 니켈, 주석)을 대상으로 수입중단 리스크 발생 시 대응이 필요한 물량과 시장이 대응할 수 있는 물량, 정부가 대응해야 하는 물량(전략비축)을 정량화하였다.

• Nuclear Engineering and Technology
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• 제54권8호
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• pp.2924-2932
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• 2022

Motivated by learning from experience and exploiting existing knowledge in civil nuclear operations, we have developed in-house generic Probabilistic Safety Assessment (PSA) models for pressurized and boiling water reactors. The models are computationally light, handy, transparent, user-friendly, and easily adaptable to account for major plant-specific differences. They cover the common internal initiating events, frontline and support systems reliability and dependencies, human-factors, common-cause failures, and account for new factors typically overlooked in many PSAs. For quantification, the models use generic US reliability data, precursor analysis reports, the ETHZ Curated Nuclear Events Database, and experts' opinions. Moreover, uncertainties in the most influential basic events are addressed. The generated results show good agreement with assessments available in the literature with detailed PSAs. We envision the models as an unbiased framework to measure nuclear operational risk with the same "ruler", and hence support inter-plant risk comparisons that are usually not possible due to differences in plant-specific PSA assumptions and scopes. The models can be used for initial risk screening, order-of-magnitude precursor analysis, and other research/pedagogic applications especially when no plant-specific PSAs are available. Finally, we are using the generic models for large-scale precursor analysis that will generate big picture trends, lessons, and insights.