• Railway Journal
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• v.18 no.5
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• pp.29-32
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• 2015

PSS 4000과 같이 표준화된, 또한 사용이 쉬운 자동화 시스템은 사용자들의 초기 투자 비용은 물론 운영 비용도 감소시킬 수 있습니다. PSS 4000-R은 철도 분야 관련 승인이 된 제품이기 때문에 인증 작업량도 상당 부분 줄일 수 있습니다. PSS 4000-R은 같은 제품을 다양한 아키텍처로 구성하여 원하는 안전 무결성 등급(SIL 2, 3, 및 4)을 만족할 수 있습니다. 이러한 어플리케이션은 철도 건설 장비는 물론 레벨 크로싱 신호 감시와 같은 신호 제어 부분에도 사용될 수 있습니다. 각 프로젝트에 적용될 다양한 조건들을 손쉽게 적용 가능함 물론 복잡한 인증 업무도 파격적으로 줄여 줄 수 있는 PSS 4000-R 솔루션은 사용자에게 엄청난 비용절감 효과를 안겨 줄 것입니다.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.295-298
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• 2007

Recently, various problems have been occurred in Apartment reconstruction process. Such as, delaying schedule, additional cost increasing, etc. Those were caused by decision making which is lack of professionality in early phase of reconstruction process. Therefore, in this study proposed improvement plan by application of project management and construction management process in Apartment reconstruction project.

• Journal of Korean Society of Steel Construction
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• v.17 no.2 s.75
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• pp.115-130
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• 2005

This paper presents the effects of indirect costs on Life-Cycle-Cost(LCC) effective optimum design of steel-box girder bridges. The LCC formulations considered in the LCC optimization of the bridges consist of initial cost and expected rehabilitation costs including repair/replacement costs, loss of contents or fatality and injury losses, and indirect costs such as road user costs and indirect socio-economic losses. To demonstrate the LCC-effectiveness for optimum design of the bridges, an actual steel box girder bridge having two continuous spans(2@50m=100m) is considered as a numerical example. And also, in this paper, various sensitivity analyses are performed to investigate the effects of indirect costs caused by traffic conditions such as number of detour route, number of lane on detour route, length of detour route, and traffic volumes on the LCC-effective optimum design. From the numerical investigations, it may be concluded that indirect costs caused by traffic network may sensitively influence on the LCC-effective optimum design of steel-box girder bridges. Therefore, it may be stated that the traffic conditions should be considered as one of the important items in the LCC-effective optimum design of the bridges.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.1
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• pp.165-172
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• 1988

An optimal network design method using continuous form of design variables is considered. Modified Hooke-and-Jeeves algorithm has been implemented in order to solve nonlinear progamming problem which is approximately equivalent to the real network design problem (NDP) with system. efficiency criteria(i. e. travel time and costs) and construction cost as objective function. Various forms of construction cost function, locations of initial solution, and dimension of initial step size of link improvement are taken into account to show the validity of this approach. The results obtained are quite promising in terms of the numbers of evaluations in solving NDP, and the speed of convergence. Finally, some techniques in choosing efficient intial solution, initial step size and approximation are given.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.04a
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• pp.1133-1138
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• 2000

최소비용 선형 망 흐름 문제가 동등한 할당 문제로 변환될 수 있으며, 또한 선형 망 흐름 문제를 해결하기 위한 전통적 방법은 단순 싸이클 흐름을 변환시킴으로서 원시 비용을 개선하는 방법이다. Auction 알고리즘이 각각의 반복에서 분산계산을 제시하는 개체와 초기의 대상 가격을 선택하기 위하여 몇 개의 특별한 법칙과 함께 동일한 문제에 적용이 될 때, 개체는 ${\varepsilon}$-이완법의 형태에서 획득할 수 있다. 본 논문은 할당 문제를 해결하기 위한 방법으로 최소비용 흐름 문제를 일반화 시켜, 전형적인 반복에 최소비용 흐름 문제, 수학적 등가에 의한 최소비용 흐름 문제를 연구하였고, 최소비용 흐름 측면에서 수송문제의 확장과 ${\varepsilon}$-이완법을 도출하여 이를 PCB 설계에 응용하고자 하였다.

• Journal of the military operations research society of Korea
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• v.36 no.2
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• pp.107-124
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• 2010

In order to estimate the life cycle expense of the weapon system acquisition from the first demand planning phase until the last disuse phase, we apply the reliable expense analysis method to the current situation in Korea by using the sensitivity analysis. We estimate the total cost of the weapon system acquisition by focusing on the most important variables such as exchange rate, and hence by strengthening the function of the existing expense analysis method, which is used to be simply recognized as a tool of cost reduction. Therefore, this study could make a contribution to the literature in this area, in terms of deriving the most cost-efficient method of acquisition by comparing the various estimated costs that result from the different alternatives of the weapon system acquisition.

• Korean Business Review
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• v.18 no.2
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• pp.21-43
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• 2005

Since China opened its market to foreign investors, overseas Chinese firms have been the biggest foreign investors. Because of the uncertain market environment, other foreign finns incurred larger liabilities of foreignness than overseas Chinese finns. Some parts of liabilities of foreignness stem from cultural differences and last for quite long time. Therefore better understanding of Chinese culture and guanxi network can give overseas Chinese finns competitive advantages over those from other countries by offering market information and reducing transaction costs. Also better management skills, information about export markets and abundant capital allow them to maintain competitive strengths over local firms. As foreign firms accumulate market knowledge in China, they can reduce liabilities of foreignness. However, it is very difficult for foreigners to understand Chinese cultures and to utilize guanxi network as well as Chinese. It is likely that Overseas Chines firms can have competitive strengths in some industries such as banking, retailing, and foreign trade, where relationship with local contractors and exploitation of worldwide Chines networks can play important roles to make successful business deals.

• Journal of Korean Society of Steel Construction
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• v.17 no.2 s.75
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• pp.227-241
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• 2005

This paper presents a practical and realistic Life-Cycle Cost (LCC) optimum design methodology for steel bridges considering the long-term effect of environmental stressors such as corrosion and heavy truck traffics on bridge reliability. The LCC functions considered in the LCC optimization consist of initial cost, expected life-cycle maintenance cost, and expected life-cycle rehabilitation costs including repair/replacement costs, loss of contents or fatality and injury losses, road user costs, and indirect socio-economic losses. For the assessment of the life-cycle rehabilitation costs, the annual probability of failure, which depends upon the prior and updated load and resistance histories, should be accounted for. For the purpose, Nowak live load model and a modified corrosion propagation model, which takes into consideration corrosion initiation, corrosion rate, and repainting effect, are adopted in this study. The proposed methodology is applied to the LCC optimum design problem of an actual steel box girder bridge with 3 continuous spans (40m+50m+40m=130m). Various sensitivity analyses are performed to investigate the effects of various design parameters and conditions on the LCC-effectiveness. From the numerical investigation, it has been observed that local corrosion environments and the volume of truck traffic significantly influence the LCC-effective optimum design of steel bridges. Thus, these conditions should be considered as crucial parameters for the optimum LCC-effective design.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.4
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• pp.342-347
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• 2016

This paper dealt with the economic analysis on the application of shipboard LED (Light Emitting Diode) luminaires to replace incandescent and fluorescent lamps, which account for over 80 % of light source on a training or naval vessel. The rates of savings achieved in the power consumption, initial investment, maintenance cost, and fuel cost were analyzed. The break-even points and the $CO_2$ emissions were also calculated. For the training vessel, the initial investment was increased by 3.8 times, while the maintenance cost over five years was reduced by 51 %. When 40 %, 50 %, and 60 % of luminaires were turned on, the calculated break-even points were 11 months, 9 months, and 7 months, respectively. On the other hand, the initial investment was increased by 3.5 times while the maintenance cost over five years was saved by 55 % for the naval vessel. The break-even points were calculated as 15 months, 12 months, and 10 months, respectively. Moreover, the $CO_2$ emissions of the training and the naval vessels were reduced by 69 % and 65 %, respectively. From the results, it was revealed that the maintenance cost can be reduced by more than 50 %, and that the power consumption, fuel cost, and $CO_2$ emissions can be reduced by more than 60 % if LED luminaires are used on two types of vessels.

• Journal of the Korean Geotechnical Society
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• v.31 no.5
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• pp.23-33
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• 2015

In the present study, a ground heat exchanger was installed for each heat source in the system at the site to evaluate ground heat conductivity, constructability, and economic feasibility; the factors considered in the study included ground heat, groundwater, fillers (such as bentonite and pea pebbles) and the shape of the heat exchange pipe (e.g., U and D-U). The aim was to determine the ground heat exchanger appropriate for the geothermal system in the 3rd-phase construction of Incheon International Airport. A comparative cost analysis of the initial costs based on the above information showed that although the initial costs of the regular vertical closed loop-II and modified vertical closed loop were lower than those of the regular vertical closed loop-I, they could not be expected to deliver high economic efficiency from the viewpoint of constructability (filler injection, heat exchange pipe insertion). The initial costs proved to be higher in the case of Geohil.