• Journal of Korean Tunnelling and Underground Space Association
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• v.5 no.3
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• pp.241-250
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• 2003

Rock mass is very inhomogeneous in nature and data obtained by site investigations and tests are very limited. For this reason, many uncertainties are to be included in the process of constructing structures in rock mass. In the design of a tunnel, support pattern, advance rate, and excavation method, which are important design parameters, must be determined to be optimal. However, it is not easy to determine those parameters. Moreover if those parameters are determined incorrectly, unexpected risk occurs such as decrease in the stability of a tunnel or economic loss due to the excessive supports etc. In this study, how to determine an optimal support pattern and advance rate, which are the important tunnel design parameters, is introduced based on a risk analysis. It can be confirmed quantitatively that the more supported a tunnel is, the larger reliability index becomes and the more stable the tunnel becomes. Also an optimal support pattern and advance rate can be determined quantitatively by performing a risk analysis considering construction cost and the cost of loss which can be occurred due to the collapse of a tunnel.

• Korean Journal of Microbiology
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• v.37 no.2
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• pp.101-108
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• 2001

Risk assessment defines as the process of estimating both the probability that an event will occur and the probable magnitude of its adverse effects. Chemical or microbial risk assessment generally follows four basic steps, that is, hazard identification, exposure assessment, dose-response assessment, and risk characterization. Risk assessment provides an effective framework for determining the relative urgency of problems and the allocation of resources to reduce risks. Using the results of risk analyses, we can target prevention, reme-diation, or control effects towards areas, sources, or situations in which the greatest risk reductions can be achieved with resources available. Risk assessment is also used to explain chemical and microbial risks as well as ecosystem impacts. Moreover, this process, which allows the quantitation and comparison of diverse risks, lets risk managers utilize the maximum amount of complex information in the decision-making process. This information can also be used to weigh the cost and benefits of control options and to develop standards or treatment options.

• Journal of the Korea Safety Management & Science
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• v.20 no.1
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• pp.1-9
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• 2018

As the chemical industry becomes more advanced, the awareness of chemical accidents is rising, and legal systems for chemical safety management are strengthened. In this study, quantitative risk assessment of liquid chlorine leak was conducted. Risk assessment was performed in the order of frequency analysis, consequence analysis, and risk calculation. The individual risk was presented in the form of contour lines. The social risk was expressed by the FN curve. The risk of day and night was in an unacceptable area, so it was required to mitigate risk. Therefore in-building, which could trap the pool, was selected as a risk mitigation measure. As a result of the cost benefit analysis, it was concluded that this measure should be reasonably implemented.

• Journal of Korea Trade
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• v.23 no.5
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• pp.45-65
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• 2019

Purpose - As the well-known Structure-Conduct-Performance paradigm implies, risk structure of a corporation may affect its risk management activity and the activity may in turn determine its performance. Depending on its goal, Foreign Direct Investment (FDI) can shape its risk structure, risk management and its performance. Under this assumption, we investigate the relationship between the goals of FDI and risk management for the first time in academics. Design/methodology - This empirical research uses a survey of 279 current Korean enterprises' FDIs in China with the recently developed business risk quadrant model. Companies are classified into either a market- or an efficiency-seeking group, to identify how each group perceives and manages risks, and values the performance of risk management. Also, we apply integrated risk management method that multinational corporations have introduced in China, then verify the mediating effect between risk factors and performance. Findings - Our research shows the FDIs can expose themselves to differing risk structure although risk management activities simply represent the level of empowerment given to local management by headquarter due to limit of sample size despite diversity of risk and risk management tools. To sum, market seekers are found to have more strategic risk (revenue related risk) than efficiency seekers with financial risk (cost related risk). The market seekers can manage their risk by empowering their local organisation while the efficiency does the opposite ways. The risk management appears to be successful in general. Originality/value - Previous studies on small and medium enterprises' FDIs to China have concentrated on the analysis of entry determinants, withdrawal factors and individual risk management. Meanwhile, this research establishes enterprise-wide risk factors faced by the companies that advance into China, according to the method of the classification by ERM and verifies if they could synthetically improve performance through risk corresponding measures.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.5
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• pp.681-688
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• 2022

According to a recent study, most construction companies in Korea do not manage risk effectively, and it is judged that the risk management system needs to be improved. In addition, most risk-related studies deal with risks from a macroscopic perspective, and there are few studies dealing with process risks at the project construction stage. Therefore, this study tried to suggest a risk response plan through analysis and classification of risk factors that may occur in retaining work among process risks. To this end, a workshop was held for risk experts to identify and analyze risks that may occur during the construction of retaining work for apartments. As a result of the study, it was expected that savings of KRW 4.97 billion would be possible in the 95 % confidence interval, and the maximum possible cost was reduced from KRW 15 billion to about KRW 10 billion. Based on the risk reduction ratio, it was found that risks that can be reduced without any special input cost, risks with large effects in response to risks, and risks with insignificant effects were found. Therefore, using the types and risk factors presented in this study as guides, it is expected that it will be helpful in successfully operating the project if an appropriate response strategy is prepared and systematically responded to the site conditions.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.3
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• pp.243-248
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• 2015

Domestic road and railroad construction have been increasingly growing and for reasons of mitigating traffic congestion, urban plan and refurbishment project, deeper and longer tunnels have been built. The event of fire is the most fatal accident in a tunnel, and it can be very disastrous with a high possibility. In this study, QRA (Quantitative Risk Analysis) which is one of quantitative risk analysis approaches was applied to tunnel fire safety design and the evaluation of QRA cases and the cost comparison of QRA methods were carried out. In addition analysis of risk reduction effect of tunnel fire safety system was conducted using AHP (Analytic Hierarchy Process) and the priority of major factors that could mitigate the risk in tunnel fire was presented. As a result, significant cost reduction effect could be obtained by incorporating QRA and it is expected to design fire safety system rationally. The priority of fire safety system based on risk mitigation effect by fire safety system considering the cost is in order of water pipe, emergency lighting, evacuation passage and smoke control system.

• Journal of Environmental Health Sciences
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• v.47 no.5
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• pp.486-495
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• 2021

Background: Particulate matter (PM) is one of the leading causes of premature death worldwide. Previous studies in South Korea have applied a relative risk calculated from Western populations when estimating the disease burden attributable to PM. However, the relative risk of PM on health outcomes may not be the same across different countries or regions. Objectives: This study aimed to estimate the premature deaths and socioeconomic costs attributable to long-term exposure to PM in South Korea. We considered not only the difference in PM concentration between regions, but also the difference in relative risk. Methods: National monitoring data of PM concentrations was obtained, and missing values were imputed using the AERMOD model and linear regression model. As a surrogate for relative risk, hazard ratios (HRs) of PM for cardiovascular and respiratory mortality were estimated using the National Health Insurance Service-National Sample Cohort. The nation was divided into five areas (metropolitan, central, southern, south-eastern, and Gangwon-do Province regions). The number of PM attributable deaths in 2018 was calculated at the district level. The socioeconomic cost was derived by multiplying the number of deaths and the statistical value of life. Results: The average PM₁₀ concentration for 2014~2018 was 45.2 ㎍/m³. The association between long-term exposure to PM₁₀ and mortality was heterogeneous between areas. When applying area-specific HRs, 23,811 premature deaths from cardiovascular and respiratory disease in 2018 were attributable to PM₁₀ (reference level 20 ㎍/m³). The corresponding socioeconomic cost was about 31 trillion won. These estimated values were higher than that when applying nationwide HRs. Conclusions: This study is the first research to estimate the premature mortality caused by long-term exposure to PM using relative risks derived from the national population. This study will help precisely identify the national and regional health burden attributed to PM and establish the priorities of air quality policy.

• YAKHAK HOEJI
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• v.51 no.3
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• pp.186-193
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• 2007

This study was performed to analyse the economic value of abciximab which is used in PCI to prevent high-risk patients with ischemic complications. The effectiveness of abciximab was extracted from published clinical trials by search-ing CCIS, and the direct medical costs relevant to using abciximab were estimated from the NHI claims database. The results in terms of cost per life-year gained (LYG) and cost per QALY gained showed that abciximab was cost-effective enough to deserve its cost. Social net benefit resulting from abciximab in PCI was estimated to be 60-70 billion Won per year.

• The Journal of Korea Robotics Society
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• v.17 no.1
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• pp.58-67
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• 2022

In this paper, we propose an approach resolving inaccuracy of the low-cost redundant manipulator workspace with low encoder and low stiffness. When the manipulators are manufactured with low-cost encoders and low-cost links, the robots can run into workspace inaccuracy issues. Furthermore, trajectory generation based on conventional forward/inverse kinematics without taking into account inaccuracy issues will introduce the risk of end-effector fluctuations. Hence, we propose an optimization for the trajectory generation method based on the DDPG (Deep Deterministic Policy Gradient) algorithm for the low-cost redundant manipulators reaching the target position in Euclidean space. We designed the DDPG algorithm minimizing the distance along with the jacobian condition number. The training environment is selected with an error rate of randomly generated joint spaces in a simulator that implemented real-world physics, the test environment is a real robotic experiment and demonstrated our approach.

• 한국벤처창업학회:학술대회논문집
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• 2009.10a
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• pp.111-138
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• 2009

This research focuses on what factors determine firm's decisions on R&D outsourcing and how R&D outsourcing affect R&D performance. In recent years many firms outsource R&D activities instead of internalizing it. Thus, further investigation is necessary to find out this recent trend. Based on several theoretical background the study developed three determining factors of R&D outsourcing which are transactional level, firm level, and risk level. Transactional level composes of independent variables such as R&D cost saving, asset specificity and uncertainty which mainly comes from Transaction Cost Economics theory. Firm level composes of openness to technology from outer source, R&D capability, and outsourcing experience. Risk level composes of technological risk, cost-related risk and managerial risk. The result shows that R&D outsourcing is significantly related to cost saving aspect, low asset specific firms, firms without solid technological background, firms which are open to external technology, firms with other types of outsourcing experience, and firms which take technological risks. However, proposed relationship between degree of R&D outsourcing and R&D performance found out to be insignificant. This research is contribute to the field of outsourcing study since it will give guidance to managers who need to make strategic decisions on R&D outsourcing activities.