• Earthquakes and Structures
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• 제24권4호
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• pp.303-316
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• 2023

Rapid post-earthquake damage estimation of subway stations is particularly necessary to improve short-term crisis management and safety measures of urban subway systems after a destructive earthquake. The conventional Performance-Based Earthquake Engineering (PBEE) framework with constant earthquake occurrence rate is invalid to estimate the aftershock risk because of the time-varying rate of aftershocks and the uncertainty of mainshock-damaged state before the occurrence of aftershocks. This study presents a time-varying probabilistic seismic risk assessment framework for underground structures considering mainshock and aftershock hazards. A discrete non-omogeneous Markov process is adopted to quantify the time-varying nature of aftershock hazard and the uncertainties of structural damage states following mainshock. The time-varying seismic risk of a typical rectangular frame subway station is assessed under mainshock-only (MS) hazard and mainshock-aftershock (MSAS) hazard. The results show that the probabilities of exceeding same limit states over the service life under MSAS hazard are larger than the values under MS hazard. For the same probability of exceedance, the higher response demands are found when aftershocks are considered. As the severity of damage state for the station structure increases, the difference of the probability of exceedance increases when aftershocks are considered. PSDR=1.0% is used as the collapse prevention performance criteria for the subway station is reasonable for both the MS hazard and MSAS hazard. However, if the effect of aftershock hazard is neglected, it can significantly underestimate the response demands and the uncertainties of potential damage states for the subway station over the service life.

• Asian Pacific Journal of Cancer Prevention
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• 제16권5호
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• pp.1759-1764
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• 2015

Purpose: To establish the concept of lung cancer hazard assessment theoretical models, evaluating the degree of lung cancer risk of Beijing for regional population lung cancer hazard assessment to provide a basis for technical support. Materials and Methods: ISO standards were used to classify stratified analysis for the entire population, life cycle, processes and socioeconomic management. Associated risk factors were evaluated as lung cancer hazard risk assessment first class indicators. Study design: Using the above materials, indicators were given the weight coefficients, building lung cancer risk assessment theoretical models. Regional data for Beijing were entered into the theoretical model to calculate the parameters of each indicator and evaluate the degree of local lung cancer risk. Results: Adopting the concept of lung cancer hazard assessment and theoretical models for regional populations, we established a lung cancer hazard risk assessment system, including 2 first indicators, 8 secondary indicators and 18 third indicators. All indicators were given weight coefficients and used as information sources. Score of hazard for lung cancer was 84.4 in Beijing. Conclusions: Comprehensively and systematically building a lung cancer risk assessment theoretical model for regional populations in conceivable, evaluating the degree of lung cancer risk of Beijing, providing technical support and scientific basis for interventions for prevention.

• 식품과학과 산업
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• 제51권3호
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• pp.185-195
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• 2018

Nutrition through food is a very important life support activity for humans in maintaining a healthy life. Nevertheless, there is no absolute safe food. In the Modern Food Law, risk analysis developed as an alternative to food safety. However, the Korean Food Sanitation Act introduced risk analysis, but many problems have arisen because the right risk concept is not reflected. To solve the problem, it is necessary to reflect the exact concept of the risk. According to our Food Sanitation Act, risks are used as risk, hazard, and harmful according to the context. The study pointed out these problems and suggested a variety of comparative legal and realistic alternatives.

• 환경영향평가
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• 제15권6호
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• pp.373-383
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• 2006

The spatial mapping of risk is very useful data in planning for disaster preparedness. This research presents a methodology for making the landslide life risk map in the Boeun area which had considerable landslide damage following heavy rain in August, 1998. We have developed a three-stage procedure in spatial data analysis not only to estimate the probability of the occurrence of the natural hazardous events but also to evaluate the uncertainty of the estimators of that probability. The three-stage procedure consists of: (i)construction of a hazard prediction map of "future" hazardous events; (ii) validation of prediction results and estimation of the probability of occurrence for each predicted hazard level; and (iii) generation of risk maps with the introduction of human life factors representing assumed or established vulnerability levels by combining the prediction map in the first stage and the estimated probabilities in the second stage with human life data. The significance of the landslide susceptibility map was evaluated by computing a prediction rate curve. It is used that the Bayesian prediction model and the case study results (the landslide susceptibility map and prediction rate curve) can be prepared for prevention of future landslide life risk map. Data from the Bayesian model-based landslide susceptibility map and prediction ratio curves were used together with human rife data to draft future landslide life risk maps. Results reveal that individual pixels had low risks, but the total risk death toll was estimated at 3.14 people. In particular, the dangerous areas involving an estimated 1/100 people were shown to have the highest risk among all research-target areas. Three people were killed in this area when landslides occurred in 1998. Thus, this risk map can deliver factual damage situation prediction to policy decision-makers, and subsequently can be used as useful data in preventing disasters. In particular, drafting of maps on landslide risk in various steps will enable one to forecast the occurrence of disasters.

• 인터넷정보학회논문지
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• 제20권3호
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• pp.1-11
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• 2019

자동차, 원자력, 철도, 항공 등의 분야에서 발생하는 소프트웨어의 고장이나 사고는 바로 큰 재산 피해나 인명 피해로 연결될 수 있다. 이에 체계적이고도 효과적인 안전품질 관리의 필요성이 커지고 있으며, 최근 관련 산업 분야에서는 IEC 61508을 기반으로 안전 국제 표준이 제정되어 산업에 적용되고 있다. 국제 표준에서 명시하고 있는 안전 생명주기에 따르면 소프트웨어 안전성 품질을 확보하기 위해서는 개발 초기 단계에서 위험원 및 위험 분석(Hazard and risk analysis)을 통한 안전 요구사항을 개발하도록 권고하고 있다. 본 논문에서는 소프트웨어의 안전성 요구사항의 식별 및 정의를 위해 SysML을 활용한 STPA 기반의 위험원 분석 프로세스를 제안한다. 세부적으로는 SysML의 BDD과 IBD 다이어그램을 활용하여 기존 STPA 분석에서 활용되고 있는 제어구조도를 보다 명확하게 정의할 수 있도록 개선하였고, SD 다이어그램을 활용하여 안전 제약사항(요구사항)을 상세화할 수 있도록 하였다. 제안 방법의 적용 결과, STPA에서 누락되었던 위험원을 추가적으로 식별할 수 있었고, 위험원의 발생 시나리오도 상세하게 구체화할 수 있었다.

• 한국환경보건학회지
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• 제42권6호
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• pp.419-429
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• 2016

Objectives: According to the new Chemical Control Act from the Korean Ministry of Environment (2014-259), workers handling hazardous chemicals should wear personal protective equipment (PPE). However the act simply states in basic phrases that every worker handling one or more of the 69 listed chemicals should wear PPE and does not consider the unique hazard characteristics of chemicals and work types. The main purpose of this study is to provide basic data to revise the act to suit particular work processes and situations. Methods: The hazard rank of the substances was classified based on hazardous characteristics such as LC50 and vapor pressure using matrix analysis. The workplace exposure risk of the substances was also determined through a matrix analysis based on the previously determined hazard ranks and the demands of manual handling together with the likelihood of accident frequency of the operation combined with the exposure of workers during spill accidents. Results: To meet the demands for developing subsequent guidelines for the risk-based application of PPE in hazardous workplaces, this study sorted the 69 listed chemicals into five hazardous categories based on their LC50 and vapor pressures, and also assigned exposure categories according to exposure vulnerability for various types of work which are frequently performed throughout the life cycle of the chemicals. Conclusion: In the next study, an exposure risk matrix will be produced using the hazard rank of chemicals and workplace exposure risk, and then PPE will be selected to suit the categories of the exposure risk matrix.

• Earthquakes and Structures
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• 제20권4호
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• pp.445-455
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• 2021

Lake Van Basin, located in Eastern Turkey, is worth examining in terms of seismicity due to large-scale losses of property and life during the historical and instrumental period. The most important and largest province in this basin is Van. Recent indicators of the high seismicity risk in the province are damage occurring after devastating earthquakes in 2011 (Mw=7.2 and Mw=5.6) and lastly in 2020 Khoy (Mw=5.9). The seismic hazard analysis for Van and its districts in Eastern Turkey was performed in probabilistic manner. Analyses were made for thirteen different districts in Van. In this study, information is given about the tectonic setting and seismicity of Van. The probabilistic seismic hazard curves were obtained for a probability of exceedance of 2%, 10% and 50% in 50-year periods. The PGA values in the Van province vary from 0.24 g - 0.43 g for earthquakes with repetition period of 475 years. Risk priorities were determined for all districts. The highest risk was calculated for Çaldıran and the lowest risk was found for Gürpınar. Risk priorities for buildings in all districts were also determined via rapid seismic assessment for reinforced-concrete and masonry buildings in this study.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2015년도 학술발표회
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• pp.236-236
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• 2015

Flood is one of the major natural disasters affecting millions of people. Thailand also, frequently faces with this type of disaster. Especially, 2011 mega flood in Central Thailand, inundated highway severely attributed to the failure of national economic and risk to life. Lesson learned from such an extreme event caused flood monitoring and warning becomes one of the sound mitigations. The highway flood hazard mapping accomplished in this research is one of the strategies. This is due to highway flood is the potential risk to life and limb, and potential damage to property. Monitoring and warning therefore help reducing live and property losses. In this study, degree of highway flood hazard was assessed by weighting factors for each cause of the highway flood using Multi Criteria Analysis (MCA) based Analytic Hierarchy Process (AHP). These weighting factors are the essential information to classify the degree of highway flood hazard to enable pinpoint on flood monitoring and flood warning in hazard areas. The highway flood causes were then investigated. It was found that three major factors influence to the highway flood are namely the highway characteristics, the hydrological characteristics and the land topography characteristics. The weight of importance for each cause of the highway flood in the whole country was assessed by weighting 3 major factors influence to the highway flood. According to the result of MCA analysis, the highway, the hydrological and the land topography characteristics were respectively weighted as 35, 35 and 30 percent influence to the cause of highway flood. These weighting factors were further utilized to classify the degree of highway flood hazard. The Weight Linear Combination (WLC) method was used to compute the total score of all highways according to each factor. This score was later used to categorize highway flood as high, moderate and low degree of hazard levels. Highway flood hazard map accomplished in this research study is applicable to serve as the handy tool for highway flood warning. However, to complete the whole warning process, flood water level monitoring system for example the camera gauge should be installed in the hazard highway. This is expected to serve as a simple flood monitor as part of the warning system during such extreme or critical event.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.951-952
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• 2006

Railway signaling systems are so vital to ensure the safe operation of railroad and the assurance and demonstration of the safety is so important. The safety management process shall consist of a number of phases and activities, which are linked to form the safety life-cycle. The basic processes of safety management and safety activity throughout the lifecycle are 'risk analysis' and 'hazard control'. The safety managements and activities for the two kinds of aspects are implemented throughout the whole steps of system lifecycle. The risk analyses and hazard controls like those are needed, these activities have to be carried out through the whole of system lifecycle.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.796-805
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• 2008

Safety Management of Korean railway industry has been rapidly changed into a risk-based approach adopted by developed countries since Railway Safety Act 2004, Rolling Stock Risk Assessment Guidance and its following regulations came into force. The fundamental requirements for the risk-based safety management is to carry out a systematic hazard identification and quantified risk analyses including cost-benefit analyses, but there has been rare a serious discussion over risk acceptance criteria and value of life in order to be able to judge the results of risk analyses and carry out cost-benefit analyses. This study presents the results of a review of risk acceptance criteria and value of life which may be adoped to Korean railway industry through the analyses with comparison of risk accepatnce principles and risk accepatnce criteria which have been already applied to other countries or other railway operators.