• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.1
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• pp.90-97
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• 2016

Sunken vessels accidents have harmful impacts on the marine environment because of oils and chemicals in the vessels. The government has managed them and developed risk assessment which can evaluate potential risk quantitatively since 1999. But the grades of present risk assessment has changed greatly depending on quantity of remaining fuel oils, and the list of remaining fuel oils omitted in status report of sunken vessels. Therefore, the aim of the study is to estimate and develop model for quantity of remaining fuel oils and verify the remaining fuel estimation comparison with active vessels. To accomplish the purpose of the study, apply this verified estimation model to current risk assessment and recommend guideline for an accurate sunken vessels risk assessment.

• Journal of Soil and Groundwater Environment
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• v.20 no.4
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• pp.51-65
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• 2015

Indoor inhalation of vapors intruded into buildings is an important exposure pathway in volatile organic compoundscontaminated sites. Site-specifically measured indoor air concentration is preferentially used for risk assessment. However, when indoor air concentration of VOC is not measured, the indoor air concentration needs to be estimated from soil concentration or measured soil gas concentration of the VOC. Some risk assessment guidance (e.g., Korea Ministry of Environment (KMOE) and American Society for Testing and Materials (ASTM) International guidance) estimate the indoor air concentration from soil concentration while other guidances (e.g., United States Environmental Protection Agency (USEPA) and Dutch National Institute for Public Health (RIVM)) estimate it from measured soil gas concentration. This study derived indoor inhalation risks of intruded benzene in two benzene-contaminated residential areas with four different risk assessment guidances (i.e., KMOE, USEPA, ASTM, and Dutch RIVM) and compared the derived risks. The risk assessment results revealed that indoor air estimation approach from soil concentration could either underestimate (when the contaminant is not detected in soil) or overestimate (when the contaminant is detected in soil even at negligible concentration) the indoor air inhalation risk. Hence, this paper recommends to estimate indoor air concentration from soil gas concentration, rather than soil concentration. Discussions about the various indoor air concentration estimation approaches are provided.

• Journal of the Korean Society of Safety
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• v.24 no.3
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• pp.96-101
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• 2009

In this study, a risk-appearance frequency evaluation model for railway level-crossing accidents is developed with the frequency estimation based on the accident history. It follows the worldwide common safety management approach and reflects the operation conditions and accident properties of the domestic railway system. The risk appearance frequency evaluation process contains a development of accident scenarios by defining the system configurations and functions, and a frequency estimation of hazardous events based on the accident history. The developed model is verified with the accident history during 5 years('03-'07) for 3 hazardous events: 'Being trapped in level crossing(Hl)', 'Crossing during warning signal(H2)' and 'Breaking through/detouring the barrier(H3)'. This risk appearance frequency evaluation model will be combined with a consequence evaluation model so as to offer full risk assessment for the railway accident. The accident risk assessment will contribute to improving the safety management of the railway system.

• Korean Journal of Construction Engineering and Management
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• v.7 no.4 s.32
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• pp.177-183
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• 2006

Risk-based estimation has been successfully introduced into the construction industry. By incorporating historical data associated with probability analysis, risk-based estimate is an effective decision support aid in considering whether to launch a particular project. The industry challenges, however, especially related with management issues, such as labor shortage, wage growth, and supply chain complexity, have often resulted in poor cost performance. The insufficient assessing the project characteristics (i.e., resource availability, project complexity, and project delivery method) can be the main reasons in the poor cost performance. Because the accuracy level of cost performance prediction can be enhanced by extensive evaluation of the subject project characteristics, a new approach for predicting cost performance in an earlier stage of a project can improve the Industry substantiality, in other words, value maximization. The purpose of this paper is to develop a new methodology in developing a risk-based estimate tool by incorporating extensive project characteristics. To do this, an extensive industry survey was conducted from both private and public sectors in building industry in Korea. In addition, significant project characteristics were identified in terms of cost performance indicator. Although the data collection is limited to Korean industry the suggested approach provides the industry with a straightforward methodology in risk management. As many researchers maintained that front-end planning efforts are crucial in achieving the successful outcome in building projects, the new method for risk-based estimation can Improve the cost performance as well as enhance the fulfillment in terms of business sustainability.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.3B
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• pp.248-253
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• 2011

Collision avoidance algorithm of vessels have been studied to avoid collision and grounding of a vessel due to human error. In this paper, We propose a collision avoidance algorithm using bayesian estimation theory for safety sailing and reduced risk of collision accident. We calculate collision risk for efficient collision avoidance using bayesian algorithm and determined the safest and most effective collision risk is predicted by using re-planned with re-evaluated collision risk in the future(t=t'). Others ship position is assumed to be informed from AIS. Experimental results show that we estimate the safest and most effective collision risk.

• Journal of the Korean Society of Safety
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• v.37 no.2
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• pp.88-96
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• 2022

Widespread infectious diseases are a concern for workers working in confined spaces. However, there is no risk assessment index for the risk of infectious disease in the workplace. Therefore, we propose a simple but effective index model to assess the risk of infectious diseases in the workplace. The proposed model identifies the risk of each workplace through an evaluation sheet comprising the frequency and intensity of the infectious disease. The intensity of an infectious disease is generally governed by the density of workers, whereas frequency is the sum of physical-e nvironmental and human management factors. By multiplying intensity and frequency, the risk of the workplace is derived. Through the proposed model, we evaluate the risks of workers at 15 different work sites. The proposed model clearly reveals what should be improved to keep workers safe from infectious diseases and will be helpful in assessing the risk of contagious disease at the work place.

• The Journal of Fisheries Business Administration
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• v.47 no.1
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• pp.87-100
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• 2016

Suhyup Bank became to be subject to regulation of capital ratio by Basel III which was introduced in order to enhance stability of the financial institution. Accordingly, Suhyup Bank will require recapitalization. It is important to estimate the risk-weighted assets in calculating of Suhyup Bank's recapitalization scale. Therefor, this study aimed to present a scientific model as estimated the risk-weighted assets. Risk-weighted assets are calculated by applying different risk weights for loans, may have a certain relationship with the loans. Results show that the risk-weighted assets is affected by the previous year's risk-weighted assets and influenced the increase in loans during the year. Since the required basic capital adequacy ratio was specified, the risk-weighted assets should be predicted reasonably. Accordingly, on this study it was tried to derive the accounting equation to predict the risk-weighted assets based on management data of a bank since introduction of Basel III. As the risk-weighted assets were weighted differently according to the type of loans, if the accounting equation is derived by using the type of loans, then it would be helpful for the risk management of banks in the long-term. According to this, the increase of loan would be predicted on the basis of past management performance of Suhyup Bank, and for this reason, the future risk-weighted assets of Suhyup Bank were predicted. The result of this study was showed that 98.3% of risk-weighted assets of the previous year, 62.4% of the secured loan changes and 95.1% of the credit loan changes affected risk-weighted assets.

• Environmental Analysis Health and Toxicology
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• v.18 no.1
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• pp.1-13
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• 2003

To estimate the annual WTP for risk reduction of environmental problems such as outdoor and indoor air pollution, and drinking water contamination, a questionnaire survey was conducted by dichotomous contingent valuation method in Seoul. Several covariate models based on Turnbull, Weibull and Spike models were developed and applied to WTP estimation with uncertainty analysis. WTP estimates for risk reduction of air pollution were 13,000 won, 12,000 won, and 10,000 won per month in low-bounded Turnbull, Weibull and Spike models, respectively. The estimates for indoor air pollution were 17,000 won,20,000 won and 21,000 won and these for drinking water contamination were 10,000 won, 13,000 won and 14,000 won in each model, respectively. Goodness of fit for Weibull model was better than those for other models. WTP estimates for indoor air pollution were higher than those for other pollution problems.

• 한국방재학회:학술대회논문집
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• 2010.02a
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• pp.16-24
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• 2010

This paper introduces the applications of Taiwan Earthquake Loss Estimation System (TELES), which is developed by the National Center for Research on Earthquake Engineering (NCREE). Seismic disaster simulation technology (SDST) integrates geographical information system to assess the distribution of ground shaking intensity, ground failure probability, building damages, casualties, post-quake fires, debris, lifeline interruptions, economic losses, etc. given any set of seismic source parameters. The SDST may integrate with Taiwan Rapid Earthquake Information Release System (TREIRS) developed by Central Weather Bureau (CWB) to obtain valuable information soon after large earthquakes and to assist in decision-making processes to dispatch rescue and medical resources more efficiently. The SDST may also integrate with probabilistic seismic source model to evaluate various kinds of risk estimates, such as average annual loss, probable maximum loss in one event, and exceeding probability curves of various kinds of losses, to help proposing feasible countermeasures and risk management strategies.

• The Korean Journal of Applied Statistics
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• v.26 no.3
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• pp.483-494
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• 2013

The importance of financial risk management has been highlighted after several recent incidences of global financial crisis. One of the issues in financial risk management is how to measure the risk; currently, the most widely used risk measure is the Value at Risk(VaR). We can consider to estimate VaR using extreme value theory if the financial data have heavy tails as the recent market trend. In this paper, we study estimations of VaR using Peaks over Threshold(POT), which is a common method of modeling fat-tailed data using extreme value theory. To use POT, we first estimate parameters of the Generalized Pareto Distribution(GPD). Here, we compare three different methods of estimating parameters of GPD by comparing the performance of the estimated VaR based on KOSPI 5 minute-data. In addition, we simulate data from normal inverse Gaussian distributions and examine two parameter estimation methods of GPD. We find that the recent methods of parameter estimation of GPD work better than the maximum likelihood estimation when the kurtosis of the return distribution of KOSPI is very high and the simulation experiment shows similar results.