• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4D
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• pp.387-396
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• 2012

Bridge is an indispensable facility as a social overhead capital. This study suggests and examines the ways of Economic valuation on maintenance alternatives for Bridge. In order to evaluate each alterative on the basis of the same time, the concepts of the basic year and the valuation year are introduced and applied. Interest rates and discount rates are also applied according to the time when each cost is incurred. This study also suggests the ways that the objects of the valuation on maintenance alternatives are not limited to construction cost, but the valuation period is fixed and so maintenance cost and remaining value incurred by maintenance alternatives are valuated. Furthermore, this study shows the way to estimate and evaluate maintenance cost through direct construction cost and annuity present value coefficient and the way to estimate remaining value based on the basic year. In addition, this study suggests economic valuation system, cost methods and analyses of the result through verification. The proposed system is considered to be applied to practical business.

• Korean Journal of Construction Engineering and Management
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• v.14 no.6
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• pp.14-21
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• 2013

While a detailed cost estimation utilizes the comprehensive quantity information obtained from a complete drawing and specification, an approximate cost estimation heavily relies on the subjective decisions. This phenomenon is because the approximate estimation is usually conducted in early stage of the construction phase where the drawing and specification are not available. This study developed a roadway construction cost estimation system which enables users to estimate the approximated cost of the project in early stage. The system identifies the variation of the construction costs due to the road route change using a cased based reasoning(CBR) method. Overall the system is expected to improves the accuracy and effectiveness of the estimation process, because it would provide users with increased accessability and consistent results in early stage of the project which leaded to the increased work transparency.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.1
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• pp.17-24
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• 2016

Many organizations have transformed their business in order to survive and compete in the future. They generate projects by creating a vision, using strategies and objectives with funds aligning strategies and make efforts to complete them successfully because project success leads to business success. All projects have triple constraints such as scope, time, and cost to be completed. Project cost performance is a key factor to achieve project goals and which is mostly related with risks among various cost drivers. Projects require a cost estimation method to complete them within their budget and on time. An accurate budget cannot be estimated due to the uncertainties and risks. Thus some additional money should be funded in addition to the base budget as a contingency reserve for identified risks and a management reserve for unidentified risks. While research on contingency reserve for identified risks included in project budget baseline have been presented, research on management reserve for unidentified risks included in total project budget is still scarce. The lack of research on estimation method and role of the management reserve have made project managers little confidence to estimate project budget accurately with reasonable basis. This study proposes a practical model to estimate budgets including contingency and management reserves for not only project cost management but also to keep the balance of organization's total funds to maximize return on investments for project portfolio management. The advantages of the proposed model are demonstrated by its application to construction projects in Korea and the processes to apply this model for verification are also provided.

• Journal of Navigation and Port Research
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• v.26 no.4
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• pp.383-390
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• 2002

The time cost of ship end cargoes is one of the most important data for decision-making of port investment and operational efficiency. Studies in this area were initiated internationally by Goss and Mann in late 70's and also done in Korea 10 years ago using the same methodology as Goss. The main purpose of this paper is to revisit to estimate the time cost using updated data. The estimation was undertaken sampling data on various investment and operating costs by vessel from 205 vessels, comprising 47.5％ of the notional fleet in Korea as well as on cargoes from international trade statistics. Compared with the study of 10 years ago, major finding of this research is that time costs of liquid and dry bulk carriers have increased, in case of the former type, showing almost doubled cost increase. The increase is deemed to be caused by very expensive LNG carriers. Lowered social discount rate in this study compared with 10 years ago, in general, has mused the costs to stay at similar level to the previous study. Sensitivity tests were conducted using various social discount rates.

• Journal of Korean Academy of Nursing Administration
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• v.14 no.2
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• pp.182-195
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• 2008

Purpose: Hospice care represents all meaningful aspects of physical, mental and economical status of the end stage patients. The purpose of this study was to estimate the cost of home-based hospice care. Method: Fifteen nurses participated in counting an hour for requirement and home visit data of 50 end stage patients were analyzed. The method of to estimate the cost of home-based hospice care was three ways. Result: In case, including traffic expense, Singles fixed fee per visit via direct inquiry was 112,970 won but in case, excluding traffic expenses, was 86,036 won and traffic expenses per visit was 26,934 won. Final cost of home-based hospice care integrated the fixed fee per the needed time for visit and fee-for services. The fixed fee per 30 minutes was 35,251 won and 60 minutes was 46,595 won and 90 minutes was 57,939 won. We included pain management and the management of emergency and bereavement care among fee-for services. Conclusion: The cost of hospice care should be establish for not only patient but the living spouse, families, and children of the dying and for anyone else affected by any patient's death.

• International Journal of Highway Engineering
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• v.11 no.1
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• pp.59-67
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• 2009

With the development of high-cost vehicle detectors, low-cost detectors have also been studied due to the advantage that more detectors are provided within limited budgets. This study proposed a method to estimate vehicle speeds using vehicles' track data from auto manufacturers and time stamps obtained when vehicles' tires pass an inclined sensor (here, a tape switch sensor). In speed estimation, small vehicles and large vehicles is distinguished according to the ratio of time stamps for a wheelbase and a rear track obtained from a tape switch sensor. In particular, speed estimation can be adjusted through a parameter to determine vehicles' size so as to take into account location properties such as vehicles' classification ratio. The low-cost vehicle detector with an inclined sensor proposed in this study is expected to be widely utilized to monitor traffic conditions thanks to low cost.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.3
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• pp.182-186
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• 2004

In this paper, the cost for capacitive reactive flower is evaluated considering the deregulation environment. For the cost assessment of reactive power, the duration curve of reactive power demand is introduced and investigated. Also, a guideline is suggested to estimate the Q-cost by using the inverse of the Q-demand duration curve. In order to obtain optimal real reactive power allocation, a new algorithm is proposed by using the piecewise linearization of the inverse of the Q-demand duration curve and the Linear Programming technique. The proposed method is tested with sample systems using MATLAB. The test results show that the algorithm yields reasonable reactive power allocation and Provides fair cost evaluation for reactive power.

• 한국연소학회:학술대회논문집
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• 2013.06a
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• pp.19-20
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• 2013

The cofiring of renewable fuel in coal fired boilers is an attractive option to mitigate $CO_2$ emissions, since it is relatively low cost option for efficiently converting renewable fuel to electricity by adding biomass as partial substitute of coal. However, it would lead to reduce plant efficiency and flexibility in operation, and increase operation cost and capital cost associated with renewable fuels handling and firing equipment. The aim of this study is to investigate reduction of carbon dioxide at varying percentage of biomass in fuel blend to the boiler biomass, and estimate operation and capital cost. Wood pellet, PKS (palm kernel shell), EFB (empty fruit bunch) and sludge are considered as a renewable fuels for a cofiring with coal. Several approaches by the cofiring ratio are chosen from past plant demonstrations and commercial cofiring operation, and they are evaluated and discussed for CO2 reduction and cost estimation.

• Journal of the military operations research society of Korea
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• v.28 no.2
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• pp.85-94
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• 2002

Calculation of proper expenses on acquisition and purchasing defense product is matter of survival and weighing the morality for both defense industry and the national facilities. With this reason, both parties have been a big job to estimate the resonable cost. The cost are composed of many subordinated parts such as material cost, labor cost, and so on. In the compositions of that cost, the most important part in between companies and the government throughout the whole calculating process is to define the proper labor cost. When both parties calculate imported articles or overhead expenses, they can easily calculate and confirm by documented evidences or related materials. In other hand, the labor cost, which can be seen as two absolutely different numbers and opinions can be created, depends on analyzer's point of view. These interpretation and judgment of data cannot avoid analyzer's intention. In accordance with the above matters, defining the reasonable labor cost will be the top priority in order to analyze the proper expenses. This study will provide a method of proper labor cost estimation before starting the actual manufacturing to calculate the rational labor cost.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.6
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• pp.4176-4184
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• 2015

Cost Estimate for alternative in design phase of construction become criterion for profitability and feasibility analysis of projects. Initial design phase performed schematic estimate based on similar data in the past. The quantity take-off according to estimators experience and calculation method are occurred different or missing. IT (Information Technology) technology evolution has been promoting BIM technology in construction. It is changing the paradigm of planning, design, construction and maintenance phase throughout the construction project. A number of studies have been attempted to apply BIM technology in the construction. In this paper, we propose schematic estimation framework linking standard format IFC (Industry Foundation Classes) and estimate related knowledge. As a result, it performs a cost prediction for decision-making in the design phase, and expected to overcome the limitations of previous studies. In addition, it is possible actively coping with changes.