• The Pure and Applied Mathematics
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• v.16 no.1
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• pp.121-131
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• 2009

In this paper we examine the relation among law-invariant coherent risk measures with the Fatou property, distortion risk measures and spectral risk measures, and give a new proof of the relation among them. It is also shown that the spectral risk measure satisfies the monotonicity with respect to stochastic dominance and the comonotonic additivity.

• Architectural research
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• v.21 no.3
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• pp.69-77
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• 2019

Architects are facing increasing risks that result from heightened expectations of benefits and performance when designing green buildings compared to traditional buildings. This study aims to explore the possible risk factors for architects in green building projects in South Korea and assess risk mitigation measures. To attain this goal, 14 risk factors and 12 mitigation measures were determined through an extensive literature review. A questionnaire was administered to architects practicing green building design and criticality index was employed to assess major risk factors and mitigation measures. This study identified 'adoption of new technology and process', 'green building certification results', 'building products and materials', and 'energy saving uncertainty' as the major risk factors of green building projects. Additionally, the questionnaire proposed 'contract indicating each party's role, liability, and limitations clearly', 'utilizing integrated design process', and 'understanding client's goal in green building projects' as the three most effective risk mitigation measures in designing green buildings. There are few studies that focus on architects' perceived risks concerning green building projects; this study contributes to a deeper knowledge and attempts to fill the current literature gap, which would benefit South Korea's green building design practice by aiding in the development of better risk management strategies.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.3
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• pp.259-267
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• 2016

The study performs a risk analysis on container ship accidents using accident data collected over the six years from 2006 to 2011, presents the resulting risk level, and suggests three risk mitigation measures to reduce the overall risk, for the safer operation of container ships. More specifically, starting from the initial accident of collision, we developed 13 different accident scenarios using event tree analysis based on which the overall risk level was obtained and presented as a FN curve. Since diverse human factors are the main cause of most of the ship accidents, our study focuses on the effect of reducing human causes on the resulting risk level. For the research we considered the injuries for the calculation of fatality with the help of MAIS. The results show that collision was the main type of accident, accounting for 62 % of all accidents, and the measures employed were proven to be effective in the sense that the risk level was much lowered and the average number of fatalities was also reduced. With more data accumulated, more precise risk level will be calculated with which the practical risk mitigating measures will be also developed. For future study, economic loss and environmental damage as consequences need to be considered.

• Journal of the Korean Society of Safety
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• v.37 no.4
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• pp.120-128
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• 2022

Printed circuit boards (PCBs) are a basic component in the electronics industry and are widely used in nearly all electronic products, such as mobile phones, tablet computers, and digital cameras, as well as in electric equipment. PCB manufacturing involves the use of many chemicals and chemical processes and therefore has more risks than other manufacturing sectors. This study aims to identify the causes of possible accidents during PCB manufacturing through risk assessment, develop and implement safety measures, and evaluate the effectiveness of these measures. Note that the safety measures developed to mitigate the risks of a certain process were also implemented for other similar processes. The risk assessments conducted over seven years, from 2015 to 2021, at a PCB manufacturing company identified 361 hazardous processes. Between 2016 and 2019, 41-56 hazardous processes were identified per year; such processes decreased to fewer than 20 per year after 2020. Application of the risk assessment results to the improvement of the hazardous processes with the similar characteristics seems to be effective in decreasing the risks. Equipment-related factors such as lack of appropriate maintenance, low work standards, and defective protection devices were responsible for 59.8% of all possible accidents. Because PCB manufacturing involves many chemicals, skin contact with hazardous substances, electric shock, fire, and explosion were the most common types of possible accidents (81.7%). In total, 505 safety measures were implemented, including 157 related to purchase and improvement of equipment and devices for safety (31.1%), 147 related to the installation/modification of fire prevention facilities (29.1%), and 69 related to the use of standard electrical appliances (13.7%). Risk assessment conducted after implementing the safety measures showed that these measures significantly decreased risk; 247 processes (68.4%) had a risk level of 3, corresponding to "very low," and 114 processes (31.6%) showed a risk level of 4, corresponding to "low." In particular, risk assessment of 104 processes with risk scores of 12 and 10 other processes with risk score of 16 showed that the risk decreased to 4 after implementing the safety measures. Thus, implementing these measures in similar manufacturing sectors that involve chemical processes can mitigate risk.

• Journal of the Korean Society of Safety
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• v.35 no.3
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• pp.16-23
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• 2020

The use of construction machinery has been increasing every year due to the large scale, high-rise and lack of workers in construction work. On the other hand, deaths are on the rise every year due to inadequate risk management for construction machinery work. In addition, the number of deaths caused by the lack of signals or insufficient signals during construction machinery work is increasing rapidly, and it is deemed necessary to analyze the actual conditions and take countermeasures. Therefore this study has developed the Strength Risk Index (SRI) based on the Frequency Risk Index (FRI) and the 5W1H by analyzing in-depth deaths caused by construction machinery over the past five years. The risk index (RI) was assessed using the frequency and strength risk index derived to determine whether it is acceptable (acceptable risk < 0.25 ≦ unacceptable risk) and the risk assessment method for reducing risk was proposed by applying 3E (Engineering, Education, Enforcement) measures for each level of risk for unacceptable risk. It also proposed measures to improve the system, such as requirements for signal numbers, mandatory placement standards, and mandatory installation of side and rear monitoring cameras, as measures for accidents caused by failure to deploy signals or insufficient signals, which account for the highest proportion of deaths among construction machinery operators and workers.

• Journal of Korean Society of societal Security
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• v.1 no.3
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• pp.69-76
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• 2008

The object of this study is to develop a tool for quantifying risks related to the rail transportation of hazardous commodities and to present mitigation measures. In this study, the Quantitative Risk Assessment (QRA) is used as a risk analysis tool. Based on the previous explosion history (Iri explosion) and consideration of its high risk, Iksan-si is selected as a model city. The result, expressed as average individual risk for exposed people with various distance, indicates that the model city is considered to be safe according to the nuclear energy standard. Also, the mitigation measures are provided since Societal risk of Iksan-si is set within ALARP. Risk reduction measures include rail car design, rail transportation operation, demage spread control as well as derail prevention and alternative routes for reducing accident frequencies. Finally, it is expected to achieve high level of public safety by appling the risk reduction measures.

• International Commerce and Information Review
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• v.9 no.2
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• pp.65-86
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• 2007

This paper reviews the properties and application methods of widely used types of risk measures, identifies the rationale and business-side effects of hedging, derives the theoretical formula of optimal hedging ratio, and analyzes the various functional aspects of VaR(Value-at-risk) as a risk measure and a hedging tool. Especially this paper focuses on the characteristics of VaR compared with other risk measures in terms of their own principal determinants and identifies its stronger aspects in the dimension of hedging strategy tools. As well, this paper provides the detailed processes deriving the optimal hedge ratios based on the distributional parameters and risk factors. In addition, this paper presents the detailed and substantial processes of estimating the minimum variance hedge ratio and minimum-VaR hedge ratio using the actual data and shows that the minimum variance hedge ratio proves helpful for many cases although it is not appropriate for the non-linear portfolio including the option contracts. We demonstrate the trade-off relationship between the minimum variance hedge strategy and the minimum-VaR hedge strategy in their hedging costs and performances through calculation of the respective VaRs and variances of unhedged and hedged portfolios and the optimal hedge ratio and hedging effectiveness values for the given long position in US Dollar with the short position in Euro.

• Industrial Engineering and Management Systems
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• v.11 no.2
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• pp.176-182
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• 2012

This paper presents a new approach to risk comparison in uncertain environment. Based on the uncertainty theory, some uncertain risk measures and risk comparison rules are proposed. Afterward the bridges are built between uncertain risk measures and risk comparison rules. Finally, several comparable examples are given.

• Journal of Korean Society for Quality Management
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• v.51 no.2
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• pp.155-170
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• 2023

Purpose: Nowadays, the risk assessment system is widely used in many industrial and public areas to reduce the possible risks. The system is used to determine the priorities of the government quality assurance works in Defense Agency for Technology and Quality. However, as the risk assessment system is used for other purposes, there are some items that need improvement, and in this study, we propose improvement plans by benchmarking the risk assessment systems of other institutions. Methods: In this paper, first, the procedures of risk assessment system used in many industrial sites were reviewed, and how each institution specialized and applied the system. Afterwards, by benchmarking various risk assessment systems, an improvement plan on how to operate the risk assessment system in the case of government quality assurance for centrally procured military supplies was presented, and practical application cases were presented to prove the usefulness of the improvement plan. Results: The proposed risk assessment system differs from the existing system in five major aspects. First, inputs, outputs, and key performance indicators were specified from the systematic point of view. Second, risk analysis was analyzed in four dimensions: probability of occurrence, impact, detection difficulty. Third, risk mitigation measures were classified, control, transfer, and sharing. Fourth, the risk mitigation measures were realized through document verification, product verification, process verification, and quality system evaluation. Finally, risk mitigation measures were implemented and the effectiveness of the risk mitigation measures was evaluated through effectiveness evaluation. Conclusions: In order for the risk assessment procedure proposed in this study to be applied to actual work, it is necessary to obtain the consent of the person involved in the work due to the increased time for risk identification and preparation of the government quality assurance log, and a change in the information system that performs the actual work is required. Therefore, the authors of this study plan to actively perform internal seminar presentations and work improvement suggestions to apply these research outputs to actual work.

• Journal of applied mathematics & informatics
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• v.27 no.3_4
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• pp.843-856
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• 2009

In possibility framework, we propose two risk measures named Fuzzy Value-at-Risk and Fuzzy Conditional Value-at-Risk, based on Credibility measure. Two portfolio optimization models for fuzzy portfolio selection problems are formulated. Then a chaos genetic algorithm based on fuzzy simulation is designed, and finally computational results show that the two risk measures can play a role in possibility space similar to Value-at-Risk and Conditional Value-at-Risk in probability space.