• Plant Journal
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• v.7 no.3
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• pp.48-64
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• 2011

In this work, risks in EPC project for overseas power plant projects are analyzed and risk management methods are suggested to reduce cost and to shorten time. 79% of risks occurred in the engineering phase for S project located in South-East Asia. The impact scales of risks on major project objectives which are cost, time, scope, and quality are analyzed as 3.5, 3.8, 2.7, and 3.7, respectively. The level of impact scales is very similar to each other except the impact scale of scope. The risk management methods suggested in this study have to be applied at the appropriate time to manage risks effectively. After that, risks are managed continuously by monitoring.

• Journal of Navigation and Port Research
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• v.30 no.7
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• pp.561-566
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• 2006

In this paper, we propose a new ship scheduling set packing model considering limited risk or variance. The set packing model is used in many applications, such as vehicle routing, crew scheduling, ship scheduling, cutting stock and so on. As long as the ship scheduling is concerned, there exits many unknown external factors such as machine breakdown, climate change and transportation cost fluctuation. However, existing ship scheduling models have not considered those factors apparently. We use a quadratic set packing model to limit the variance of expected cost of ship scheduling problems under stochastic spot rates. Set problems are NP-complete, and additional quadratic constraint makes the problems much harder. We implement Kelley's cutting plane method to replace the hard quadratic constraint by many linear constrains and use branch-and-bound algorithm to get the optimal integral solution. Some meaningful computational results and comments are provided.

• Wind and Structures
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• v.14 no.1
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• pp.71-80
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• 2011

This study presents a decision making process for installation of wind barrier which is used to reduce the wind speed applied to running vehicles on expressway. To determine whether it is needed to install wind barrier or not, cost and benefit from wind barrier are calculated during lifetime. In obtaining car accidental risk, probabilistic distribution of wind speed, daily traffic volume, mixture ratio in the volume, and duration time for wind speed range are considered. It is recommended to install wind barrier if benefit from the barrier installation exceed construction cost. In the numerical examples, case studies were shown for risk and benefit calculation and main risky regions on Korean highway were all evaluated to identify the number of installation sites.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.29 no.2
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• pp.1-13
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• 2021

Fuel costs represent one of the most substantial expenses for airlines, accounting for 20% - 36% of the airline's total operating cost. The present study discusses the so-called discretionary fuel that is additionally loaded at the discretion of airlines to cover unforeseen variations from the planned flight operations. The proper range of the discretionary fuel to be loaded for economic flight operations was estimated by applying Monte Carlo simulation technique. With this simulation model for loading discretionary fuel, airlines cannot only reduce the total amount of fuel to be consumed but also minimize the risk of unplanned flight disruptions caused by insufficient fuel on board. Airlines should be able to guarantee proper risk management processes for fuel boarding by carrying enough fuel to high-risk airports. This study would provide a practical guideline for loading proper amounts of discretionary fuel. Future researchers should be encouraged to improve this study by elaborating the weather variable.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.483-488
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• 2019

This study first examines whether the high matching principle reduces the cost of equity, and then examines the effect on discretionary accruals and capital cost. According to previous studies, the higher the response to revenue cost, the higher the earnings quality. The higher the quality of earnings, the lower the information risk, and the lower the information risk, the lower the capital cost of enterprise. Discretionary accruals can play two roles in opposing each other. One is that managers use the discretionary accruals to provide private information about the future of the corporation to the market, thus enhancing the usefulness of the earnings. The other is that managers can use the discretionary accruals opportunistically to distort earnings and provide misinformed information to investors, thus reducing the usefulness of earnings. The results of this study represents that the higher the responding to the revenue cost, the less the cost of equity. In the case of firms with high revenue response, we examine whether discretionary accruals reduce the cost of equity capital. As a result of the study, the higher the responding to the revenue cost, the lower the cost of equity capital. Companies with higher matching principle have been shown to reduce their capital costs by using discretionary accruals.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.143-144
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• 2012

A number of construction projects tied to the concerns and decision-making is also very complicated. In addition, more than any other industry, is inherent in many risk factors. In the course of the construction project on risk factors that exist in the early stages of project risk factors to predict in advance and prepare a project by shortening the construction period and project cost as you can to maximize performance. In this study, I proposed risk management processes and how they are used in web-based schedule risk in the process of change management system, and between 3D CAD, 4D CAD taking into account the linkages, risk management strategy process in the BIM environment.

• Korean Journal of Construction Engineering and Management
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• v.17 no.2
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• pp.70-79
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• 2016

The current remodeling cost estimation process is not only dependent on the historical data of new building construction, but it also has a poor linkage with risk-based estimation approach. As such, there is a high risk of falling short of initial budget. To overcome this, a risk-based estimation approach is necessary by providing a probabilistic estimation in consideration of the potential risk factors in conducting the remodeling projects. In addition, the decision-making process should be linked with the risk-based estimation results in stead of intuitive and/or experience-based estimation. This study provides a probabilistic estimation process for residential remodeling projects by developing a detailed methodology in which a step-by-step approach can be achieved. The new proposed estimation approach can help in decision-making for remodeling projects in terms of whether to proceed or not, by effectively reflecting the potential risk factors in the early stage of the project. In addition, the study can enhance the reliability of the estimation results by developing a sustainable estimation process model where a risk-based evaluation can be accomplished by setting up the cost-risk relationship database structure.

• Journal of the Korean Institute of Gas
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• v.16 no.6
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• pp.80-86
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• 2012

From 1982, the Korean Ministry of Employment and Labor has executed the risk assessment regulation for manufacturing industries. When a manufacturing company install, transfer, or modify the major facilities, the program inspects and verifies safety of the working place to ensure safety against risks. This study performed cost-benefit analysis of the program for the eight industrial categories that were free from the program. The cost-benefit analysis is the basic method to estimate the effect of the policy execution, and used to justify the policy effectiveness. As a result, there is the biggest benefit in the manufacture of basic metal products and then motor vehicles, trailers and semitrailers, other manufacturing, other machinery and equipment, wood products of wood and cork, rubber and plastic products, food products, furniture in order. Thus the hazard prevention program should be applied into the 8 industrial categories in order to strengthen national competitiveness, protect labors's safety, reduce the social cost and improve the welfare.

• Proceedings of the KIEE Conference
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• 2006.11a
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• pp.393-395
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• 2006

In competitive market, it is important to establish a plan of transmission expansion considering uncertainty of future generation and load behavior. For this reason, revised transmission expansion model is proposed in this paper. In the proposed model, information of predictable future condition are included in a cost function of transmission expansion investment. Also, to reduce risk of the investment, mean-variance Markowitz approach is added to the objective function of cost. By optimization programming, the most robust and the minimum cost plan can be obtained.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.1
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• pp.9-16
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• 2016

The project schedule risk in the engineering and facility construction industry is increasingly considered as important management factor because the risks in terms of schedule or deadline may significantly affect the project cost. Especially, the project-based operating companies attempt to find the best estimate of the project completion time for use at their proposals, and therefore, usually have much interest in accurate estimation of the duration of the projects. In general, the management of projects schedule risk is achieved by modeling project schedule with PERT/CPM techniques, and then performing risk assessment with simulation such as Monte-Carlo simulation method. However, since these approaches require the accumulated executional data, which are not usually available in project-based operating company, and, further, they cannot reflect various schedule constraints, which usually are met during the project execution, the project managers have difficulty in preparing for the project risks in advance of their occurrence in the project execution. As these constraints may affect time and cost which role as the crucial evaluation factors to the quality of the project result, they must be identified and described in advance of their occurrence in the project management. This paper proposes a Bayesian Net based methodology for estimating project schedule risk by identifying and enforcing the project risks and its response plan which may occur in storage tank engineering and construction project environment. First, we translated the schedule network with the project risks and its response plan into Bayesian Net. Second, we analyzed the integrated Bayesian Net and suggested an estimate of project schedule risk with simulation approach. Finally, we applied our approach to a storage tank construction project to validate its feasibility.