• Nuclear Engineering and Technology
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• v.52 no.5
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• pp.975-983
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• 2020

Since the Fukushima Daiichi accident in 2011, concerns for the safety of multi-unit Nuclear Power Plant (NPP) sites have risen. This is because more than 70% of NPP sites are multi-unit sites that have two or more NPP units and a multi-unit accident occurred for the first time. After this accident, Probability Safety Assessment (PSA) has been considered in many countries as one of the tools to quantitatively assess the safety for multi-unit NPP sites. One of the biggest concerns for a multi-unit accident such as Fukushima is that the consequences (health and economic) will be significantly higher than in the case of a single-unit accident. However, many studies on multi-unit PSA have focused on Level 1 & 2 PSA, and there are many challenges in terms of public acceptance due to various speculations without an engineering background. In this study, two kinds of multi-unit Level 3 PSA for multi-unit site have been carried out. The first case was the estimation of multi-unit risk with conservative assumptions to investigate the margin between multi-unit risk and QHO, and the other was to identify the effect of time delays in releases between NPP units on the same site. Through these two kinds of assessments, we aimed at investigating the level of multi-unit risk and understanding the characteristics of risk in a multiunit context.

• The Journal of Asian Finance, Economics and Business
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• v.10 no.1
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• pp.57-66
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• 2023

There is a strong association between poverty levels and the probability of natural disasters. East Java, however, exhibits a distinct pattern. While the rate of poverty is declining, natural disasters are becoming more severe. Considering that East Java is an area with a high risk of natural disasters and a high poverty rate, this study aims to estimate the effect of environmental preservation and the magnitude of the impact of disasters as measured by the Disaster Risk Index (IRBI) on poverty. The 3SLS model is used on secondary data from 38 districts/cities from 2015 to 2021 as an analytical database. Based on the estimation results, there are 3 findings in this study: (i) the role of government, population development, and economic activity have a strong influence on nature conservation; (ii) nature conservation has a strong influence on disaster risk; and (iii) the disaster risk index has a strong effect on poverty. As a result, areas with a high level of disaster risk have a slower rate of poverty reduction. The role of this research is to show the need for the government's role in improving the quality of natural disaster mitigation anticipation, economic activity, and the role of the population in a sustainable manner.

• The Journal of Bigdata
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• v.7 no.2
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• pp.225-234
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• 2022

In this paper, we study the recent changes in the credit risk interconnectedness in Korea. Using the CDS spread data from November 2015 to August 2022, we estimate the network structure of sovereign and corporate credit risk. The results show that sovereign and corporate credit risks are interconnected significantly, particularly with respect to the banking sector where FX-related transactions are made. Since 2022 when the monetary policy has become contractionary, such credit risk interconnectedness seems to be strengthened because of greater common exposure.

• Journal of Navigation and Port Research
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• v.43 no.3
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• pp.166-171
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• 2019

Aids to Navigation(AtoN) Accident can reduce the credibility of AtoN by adding extra works to the administrators, and cause burdens and inconveniences to the users during their navigation leading to social costs (or economic losses). Prior research on social cost estimation model to determine the Encounter cost, Administrative cost and Risk cost on the Aton model was done to estimate the economic losses due to AtoN Accident. However, this research could not provide adequate study results on risk cost estimates. Therefore, this study complements the estimation model presented in the previous study, and the estimated social cost of 249 AtoN Accidents that occurred during the last 10 years (2008-2017) in the Busan Regional Office of Oceans and Fisheries jurisdiction area. The risk cost was estimated using contingent valuation method since the AtoN is a non-market goods. As a result, the social cost of AtoN Accidents for the past 10 years was estimated to total 12.4 billion won including Encounter cost of 3.1 billion won (25.38%), Administrative cost of 1.7 billion won (13.62%), and Risk cost of 7.5 billion won (61.01%).

• Journal of the Society of Disaster Information
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• v.18 no.3
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• pp.444-456
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• 2022

Purpose: Laboratories require Preliminary Risk Analysis of Hazard Factors, but there are many laboratories that do not. For the purpose of securing the safety of the laboratory, it is intended to find improvements so that the Risk Assessment can be easily applied. Method: Research papers and data from the Laboratory Safety Management Survey Report by the Ministry of Science and ICT were used. The study was conducted by comparing Preliminary Risk Analysis of Hazard Factors and Risk Assessment under the Occopational Safety and Health Act. Result: A technique for Risk Assessment of a laboratory was proposed. When Risk Assessment of the laboratory, a method was proposed to estimate the size of the possibility(frequency) and severity(intensity). Conclusion: For easy application in the laboratory, a checklist-type Risk Assessment technique was presented and actual evaluation was conducted. It is expected that the laboratory will improve through Risk Assessment to help prevent safety accidents.

• Asia-Pacific Journal of Business
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• v.11 no.3
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• pp.243-260
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• 2020

Purpose - This paper aims to investigate the properties of crude oil based derivative security (DLS) focusing on step-down type for comprehensive understanding of its risk. Design/methodology/approach - Kernel estimation is conducted to figure out statistical feature of the process of oil price. We simulate oil price paths based on kernel estimation results and derive probabilities of hitting the barrier and early redemption. Findings - The amount of issuance for crude oil based DLS is relatively low when base prices are below $40 while it is high when base prices are around $60 or $100, which is not consistent with kernel estimation results showing that oil futures prices tend to revert toward $46.14 and the mean-reverting speed is faster as oil price is lower. The analysis based on simulated oil price paths reveals that probability of early redemption is below 50% for DLS with high base prices and the ratio of the probability of early redemption to the probability of hitting barrier is remarkably low compared to the case for DLS with low base prices, as the chance of early redemption is deferred. Research implications or Originality - Empirical results imply that the level of the base price is a crucial factor of the risk for DLS, thus introducing a time-varying knock-in barrier, which is similar to adjust the base price, merits consideration to enhance protection for DLS investors.

• Journal of Ocean Engineering and Technology
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• v.26 no.1
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• pp.60-63
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• 2012

The accident risks in the marine environment are increasing because of the tendency to build faster and larger ships. To secure ship safety, risk-based ship design (RBSD) was recently suggested based on a formal safety assessment (FSA). In the process of RBSD, a ship designer decides which risk reduction option is most cost-effective in the design stage using a cost-benefit analysis (CBA). There are three dimensions of risk in this CBA: fatality, environment, and asset. In this paper, we present an approach to estimate the environmental costs based on the size of an oil tanker involved in an accident using a neural network. An appropriate neural network model is suggested for the estimation,and the neural network is trained using IOPCF data. Finally,the learned neural network is compared with the cost regression equation by IMO MEPC 62/WP.13 (2011).

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.3
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• pp.191-199
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• 2012

Objectives: The study aim was to evaluate the application of a chemical exposure assessment tool for the Korean workplace. The Ministry of Employment and Labor in Korea (KMOEL) introduced the need for workplace risk assessments in 2011, requiring the Korean chemical industry to consider both domestic and international chemical regulation policies (e.g., estimations of exposure scenarios). Exposure scenarios are required in the European Union as part of material safety data sheets (MSDS) under the Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH) system. Methods: Although many programs for the estimation of exposure have been developed worldwide, to date there is no standard for the Korean workplace. To develop programs suitable for the Korean workplace, we examined the applicability of the European Center for Ecotoxicology and Toxicology of Chemicals target risk assessment (ECETOC TRA), which is recommended by the European Chemical Agency (ECHA). Results: To investigate the applicability of the ECETOC TRA to Korean industry, this study simulated 15 industrial processes. The predicted respiratory exposures for four processes using origin input parameters were underestimated compared to the measured respiratory exposure. Using calibrated input parameters, results for two processes were underestimated compared to the measured respiratory exposure. This result suggests that the use of calibrated input parameters reduces the differences between predicted and measured respiratory exposure. Conclusions: we developed applicable exposure estimating method by modifying the ECETOC TRA program; one suggested the development of exposure estimating program that explains Korea domestic workplace exposure scenario.This study will support the introduction of exposure scenario in MSDS system and protect health of worker from hazardous chemical.

• Health Policy and Management
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• v.31 no.4
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• pp.451-461
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• 2021

Background: Readmissions related to lack of quality care harm both patients and health insurance finances. If the factors affecting readmission are identified, the readmission can be managed by controlling those factors. This paper aims to identify factors that affect readmissions of convalescent rehabilitation patients. Methods: Health Insurance Review and Assessment Service claims data were used to identify readmissions of convalescent patients who were admitted in hospitals and long-term care hospitals nationwide in 2018. Based on prior research, the socio-demographics, clinical, medical institution, and staffing levels characteristics were included in the research model as independent variables. Readmissions for convalescent rehabilitation treatment within 30 days after discharge were analyzed using logistic regression and generalization estimation equation. Results: The average readmission rate of the study subjects was 24.4%, and the risk of readmission decreases as age, length of stay, and the number of patients per physical therapist increase. In the patient group, the risk of readmission is lower in the spinal cord injury group and the musculoskeletal system group than in the brain injury group. The risk of readmission increases as the severity of patients and the number of patients per rehabilitation medicine specialist increases. Besides, the readmission risk is higher in men than women and long-term care hospitals than hospitals. Conclusion: "Reducing the readmission rate" is consistent with the ultimate goal of the convalescent rehabilitation system. Thus, it is necessary to prepare a mechanism for policy management of readmission.

• Journal of Environmental Impact Assessment
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• v.15 no.6
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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.