• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.3
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• pp.302-310
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• 2018

Despite the accident rate for fishing vessels accounts for 70% of all maritime accidents, few studies on such accidents have been done and most of the them mainly focus on causes and mitigation policies to reduce that accident rate. Thus, this risk analysis on sea accidents is the first to be performed for the successful and efficient implementation of accident reducing measures. In risk analysis, risk is calculated based on the combination of frequency and the consequence of an accident, and is usually expressed as a single number. However, there exists uncertainty in the risk calculation process if one uses a limited number of data for analysis. Therefore, in the study we propose a probabilistic simulation method to forecast risk not as a single number, but in a range of possible risk values. For the capability of the proposed method, using the criteria with the ALARP region, we show the possible risk values spanning across the different risk regions, whereas the single risk value calculated from the existing method lies in one of the risk regions. Therefore, a decision maker could employ appropriate risk mitigation options to handle the risks lying in different regions. For this study, we used fishing vessel accident data from 1988 to 2016.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.3
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• pp.49-56
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• 2011

This paper deals with a methodology for searching optimal route of hazard material (hazmat) vehicles. When we make a decision of hazmat optimal paths, there is a conflict between the public aspect which wants to minimize risk and the private aspect which has a goal of minimizing travel time. This paper presents Efficient Vector Labeling algorithm as a methodology for searching optimal path of hazmat transportation, which is intrinsically one of the multi-criteria decision making problems. The output of the presented algorithm is a set of Pareto optimal paths considering both risk and travel time at a time. Also, the proposed algorithm is able to identify non-dominated paths which are significantly different from each other in terms of links used. The proposed Efficient Vector Labeling algorithm are applied to test bed network and compared with the existing k-shortest path algorithm. Analysis of result shows that the proposed algorithm is more efficient and advantageous in searching reasonable alternative routes than the existing one.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1414-1418
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• 2009

International construction projects typically manifest difficult, complex, and varied types of risk exposures; because of this, there is a need for accurate evaluation of risk-integrated performances during the timeframe of project execution. Given the financial crisis currently affecting the world economy recession, risk management has become a more crucial part for the success of international project management. However, the majority of risk management approaches, particularly for overseas projects, are focused primarily on simple forms of checklists, formalization of risk variables affecting project performance for a specific phase, or more complicated computational methods that restricting practical utilization in real-world projects; moreover, these methods lack the conceptual basis to broadly visualize the level of risk over all phases of a project. This study suggests an efficient, yet simple risk-integrated total index to successfully assess the risk levels of overseas construction projects. To this end, this paper first investigates the life cycles and key processes of decision-making for a given project and then derives formulas to represent the total risk index (TRI) along the key decision-making processes. In addition, the study examines the relationships between TRI and performance levels based on the analysis of 126 real-world project samples. Validations using the proposed TRI showed a high correlation to project performance, signifying the usefulness of the proposed approach for construction firms when investigating the level of risks and key areas for management focus.

• Geomechanics and Engineering
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• v.22 no.3
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• pp.207-217
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• 2020

Slope reliability analysis and risk assessment for spatially variable soils under rainfall infiltration are important subjects but they have not been well addressed. This lack of study may in part be due to the multiple and diverse evaluation indexes and the low computational efficiency of Monte-Carlo simulations. To remedy this, this paper proposes a highly efficient computational method for investigating random field problems for slopes. First, the probability density evolution method (PDEM) is introduced. This method has high computational efficiency and does not need the tens of thousands of numerical simulation samples required by other methods. Second, the influence of rainfall on slope reliability is investigated, where the reliability is calculated from based on the safety factor curves during the rainfall. Finally, the uncertainty of the sliding mass for the slope random field problem is analyzed. Slope failure consequences are considered to be directly correlated with the sliding mass. Calculations showed that the mass that slides is smaller than the potential sliding mass (shallow surface sliding in rainfall). Sliding mass-based risk assessment is both needed and feasible for engineered slope design. The efficient PDEM is recommended for problems requiring lengthy calculations such as random field problems coupled with rainfall infiltration.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.17
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• pp.129-146
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• 2002

The electronic technology development have occurred in the face of existing legal barriers to legal efficacy of computer information goods, and the liberating promise of electronic transactions cannot fully realized unless there is predictability in the legal rules that govern such transactions. This study analyzes some theoretical fundamentals of the Act. First, it proposes that the Act clarify and set forth uniform legal principles applicable to computer information transactions. Secondly, it suggests that if the individual is risk averse, the acceptance set for electronic transactions will be a convex set, and that the application of the Act will make the acceptance set more expanded by lowering the probability of conflicts and by downsizing the risk averness. Thirdly, it also suggest that through the mothod of contingent commodities analysis, the application of the Act by means of its restricted regulations will give more expected utility than the absence of the Act. Fourthly, it derives some implications that the degree of legitimate restriction will be affected by the objective risk inherent to the electronic transactions, and the individual's subjective risk-averseness. Finally, it concludes that harmonization of restriction and protection of individual's rights in electronic transaction process will be a necessary condition for more efficient body of law from the law-economic perspectives.

• Journal of the Korea Safety Management & Science
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• v.24 no.4
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• pp.61-70
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• 2022

In spite of lab safety act for over 10 years, over 100 safety accidents in the laboratory have been constantly occurring. The ideal safety management system is to prevent accidents by differential classifying and managing laboratory regulatory materials according to the risk level. In order to approach this system, in-depth interviews with safety managers were first conducted to identify the current status of safety management in domestic university laboratories. And then through comparative analysis of safety management systems in domestic and foreign laboratories, a new regulatory substance classification standard based on the analysis of the hazards and the classification of risk grades, and a safety management system are proposed. From this study, it will contribute to the creation of a safe laboratory environment by differential classification and management laboratory regulatory materials based on the risk level.

• International Commerce and Information Review
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• v.3 no.2
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• pp.1-16
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• 2001

This study discusses some theoretical implications for efficient utilization of the global E-commerce in a world of uncertainty by beginning with measures of risk and return for the global E-commerce, and by moving to risk and return for a efficient transaction portfolio of many risky methods of transaction. Decision rules are developed to show how individuals choose optimal transaction portfolios that maximize their expected utility of wealth. First, the individuals will generally want to allocate positive amount to the global E-commerce, which requires that the expected marginal utility of wealth equals zero. Secondly, the optimal transaction portfolio will be determined by finding the point of tangency between the efficient trading line and the hightest indifference curve in the mean-variance plane. Thirdly, if the global E-commerce is positively correlated with wealth, it must have an expected return that is higher than the risk-free transaction methods in order to compensate for its risk. Fourthly, on the other hand, if the global E-commerce is negatively correlated with wealth, it will have an expected return that is less than the risk-free transaction methods. Finally, the valuation of global E-commerce depends on the degree of individual's risk aversion and the covariance between the expected return of total wealth and the return of global E-commerce.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.409-412
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• 2002

In this presentation, the methods that is appropriate to remediate the farmland contaminated by petroleum hydrocarbon was considered using the case histories of the abroad. As a result of a consideration, most remediation procedures were based risk assessment and management, risk-based procedure. It is also useful to use natural attenuation mechanism to remediate petroleum-contaminated sites. However, more research efforts are demanded for developing a cost-effective and efficient technologies.

• Journal of the Korean Society of Safety
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• v.27 no.4
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• pp.62-67
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• 2012

Risk Assessment, a basis of health and safety management system, is an calamity prevention activity which regularly measure the level of a risk to passively improve potential hazard. A problem, the assessment not being improved to be applied to the construction work site where requires diversity and complexity, causes the assessment to be inefficient to bring quality results. A study on the investigates and compares the surveyed degree of recognitions of workers who works in companies executing the risk assessment By the investigation and comparison, it is expected to bring the better solution for early and efficient application for those companies which are not taking the risk assessment.

• Korean Management Science Review
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• v.30 no.3
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• pp.55-70
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• 2013

In this study we suggested two optimization models to determine conversion weight of convertible bonds. The problem of this study is same as that of Park and Shim [1]. But this study used Value-at-Risk (VaR) for risk measurement instead of CVaR, Conditional-Value-at-Risk. In comparison with conventional Markowitz portfolio models, which use the variance of return, our models used VaR. In 1996, Basel Committee on Banking Supervision recommended VaR for portfolio risk measurement. But there are difficulties in solving optimization models including VaR. Benati and Rizzi [5] proved NP-hardness of general portfolio optimization problems including VaR. We adopted their approach. But we developed efficient algorithms with time complexity O(nlogn) or less for our models. We applied examples of our models to the convertible bond issued by a semiconductor company Hynix.