• Journal of the Korean Institute of Gas
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• v.13 no.4
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• pp.53-60
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• 2009

For the case of the facilities using utilities such as cooling water and steam, risk of the facilities is zero because the consequence of failure (COF) through equipment damage area is zero. Therefore, to improve the estimation method of the risk by COF through equipment damage area in the risk-based inspection (RBI), this study developed the procedures of RBI, in which the risk was estimated by COF through financial loss. And, the RBI program (KS-RBI Ver 3.1) was developed to establish inspection interval based on the risk of the facilities estimated by COF through equipment damage area and financial loss, simultaneously, and the developed RBI program was applied to a petrochemical process. As a result, risks of the facilities estimated by COF through financial loss were similar to risks by COF through the equipment damage area. But, for the case of the facilities using utilities or expensive facilities, the estimation method of the risk by COF through financial loss was more accurate than through equipment damage area.

• Atmosphere
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• v.34 no.1
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• pp.1-21
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• 2024

Private companies are increasingly required to take more substantial actions on climate change. This study introduces the principle and cases of climate (physical) risk estimation for 11 private companies in Korea. Climate risk is defined as the product of three major determinants: hazard, exposure, and vulnerability. Hazard is the intensity or frequency of weather phenomena that can cause disasters. Vulnerability can be reflected in the function that explains the relationship between past weather records and loss records. The final climate risk is calculated by multiplying the function by the exposure, which is defined as the area or value of the target area exposed to the climate. Future climate risk is estimated by applying future exposure to estimated future hazard using climate model scenarios or statistical trends based on weather data. The estimated climate risks are developed into three types according to the demand of private companies: i) climate risk for financial portfolio management, ii) climate risk for port logistics management, iii) climate risk for supply chain management. We hope that this study will contribute to the establishment of the climate risk management system in the Korean industrial sector as a whole.

• Nuclear Engineering and Technology
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• v.53 no.11
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• pp.3465-3473
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• 2021

For a long time, research into integrated deterministic-probabilistic safety assessment has been continuously conducted to point out and overcome the limitations of classical ET (event tree)/FT (fault tree) based PSA (probabilistic safety assessment). The current paper also attempts to assert the reason why a technical transformation from classical PSA is necessary with a re-interpretation of the categories of risk. In this study, residual risk was classified into interpolating- and extrapolating-censored categories, which represent risks that are difficult to identify through an interpolation or extrapolation of representative scenarios due to potential nonlinearity between hardware and human behaviors intertwined in time and space. The authors hypothesize that such risk can be dealt with only if the classical ETs/FTs are freely relocated, entailing large-scale computation associated with physical models. The functional elements that are favorable to find residual risk were inferred from previous studies. The authors then introduce their under-development enabling techniques, namely DICE (Dynamic Integrated Consequence Evaluation) and DeBATE (Deep learning-Based Accident Trend Estimation). This work can be considered as a preliminary initiative to find the bridging points between deterministic and probabilistic assessments on the pillars of big data technology.

• Communications for Statistical Applications and Methods
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• v.14 no.1
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• pp.71-80
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• 2007

The present paper investigates estimation of a scale parameter of a gamma distribution using a loss function that reflects both goodness of fit and precision of estimation. The Bayes and empirical Bayes estimators rotative to balanced loss functions (BLFs) are derived and optimality of some estimators are studied.

• Journal of applied mathematics & informatics
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• v.6 no.2
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• pp.661-668
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• 1999

Reliability estimation using Gibbs sampler considered for modeling mixture exponential reliability problems. Gibbs sampler is developed to compute the features of the posterior distribution. Bayesian estimation of complicated functions requires simpler esti-mation techniques due to the mathematical difficulties involved in the Bayes approach. The Maximum likelihood estimator and the Gibbs estimator of reliability of the system are derived. By simula-tion risk behaviors of derived estimators are compared. model de-termination based on relative error is considered. A numerical study with a simulated data set is provided.

• Journal of the Korean Society of Safety
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• v.14 no.4
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• pp.120-125
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• 1999

This study evaluated the effect of the accidents caused by fire, explosion, and toxic gas release by using SuperChems, quantitative hazardous material release modeling software, which estimates the potential area of damage. According to the loss severity, the appropriate risk management principles can be applied. Risk management is divided into the two methods which are risk control and risk financing. Risk control includes risk avoidance, risk spreading and diversification, and risk reduction. Risk financing includes risk retention and risk transfer. The results of this study can help the related company determine the appropriate reserve fund and the amount to be insured against the third party losses according to the estimated loss severity.

• Journal of Construction Engineering and Project Management
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• v.3 no.2
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• pp.49-57
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• 2013

A sea dike construction has been increased in Korea because of the actively deployed reclamation project in basis of efficient application in land. The degree of completion in sea dike construction is affected by final closing construction, which has a lot of uncertainty that often results in higher accidents rate. Therefore, this research identified risk factors of final closing construction and classified them. This research examines the likelihood and its impact for each risk factor and calculates the risk degree as to the risk matrix. Based on this, the impact and the environmental conditions that affect to risk factors are investigated and further responsive methods are established for each risk factor. Ultimately, this research attempts to provide the risk retrenchment method for inspectors by proposing risk estimation model, responsive action list, and risk management process.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.870-877
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• 2006

Recently, failures of equipments are linked directly to extensive damages of human lives or financial losses from the increasing uses of train control equipments utilizing computers. Then safety activities have to progress for guaranteeing safety during the system life-cycle. In this paper, we examine the methods for risk analysis and assessment of safety activities and propose optimized one method for risk assessment. There are original risk assessment methods; risk graph and risk matrix method under the qualitative analysis, IRF(Individual Risk Formula) calculations and statistical calculations method under the quantitative analysis. Best-Practice(BP) risk analysis method is proposed for combining advantages of the qualitative and the quantitative analysis. In the comparison of risk graph and risk matrix method for safety estimation, BP method has no applications published up to now, but we can expect that this method will be utilized widely for the risk assessment due to various strong points.

• The Korean Journal of Applied Statistics
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• v.23 no.4
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• pp.669-681
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• 2010

Value-at-Risk(VaR) is an important part of risk management in the financial industry. This paper present a VaR forecasting for financial time series based on the quantile regression for GARCH models recently developed by Lee and Noh (2009). The proposed VaR forecasting features the direct conditional quantile estimation for GARCH models that is well connected with the model parameters. Empirical performance is measured by several backtesting procedures, and is reported in comparison with existing methods using sample quantiles.

• The Journal of Information Systems
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• v.13 no.1
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• pp.1-20
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• 2004

Most of the software development projects bear risks that need analysis and management. Risk management plays a critical role for the success of software project management. In this study, we have used delphi method to delineate critical risk factors. The study pulls out 20 project risk factors from 21 project managers. It is certainly clear that certain features are more risky than others. Our study shows that unrealistic cost estimation and changes in scope and objective are more risky than other features.