• Convergence Security Journal
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• v.13 no.1
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• pp.11-17
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• 2013

In this paper, the information security requirements in the mobile ad-hoc network(MANET) are presented, and the algorithm to establish the protection node(gateway) is proposed to prevent the distributed denial of service(DDoS). The information security technology and security threats in the MANET are presented, and protection node is decided to minimize the total cost through the sending nodes and receiving nodes by way of protection node. To set up the protection node, the minimization algorithms of maximum cost and the average cost between the protection node and receiving nodes are compared with the optimal solutions, in which optimal solution is found out by all enumeration method. From the results, the total cost between the sending and receiving nodes is minimized under the average cost minimization algorithm rather than the using of the maximum cost.

• Environmental and Resource Economics Review
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• v.6 no.2
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• pp.209-231
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• 1997

본 논문은 전통적인 산업연관분석이 고정투입계수를 시용하고 있어서 상대가격체계의 변화에 따른 경제 주체들의 비용최소화 노력을 모형 내에 반영하지 못하고 있다는 한계를 극복하기 위하여 상대가격체계의 변화에 따라 가변투입계수를 갖는 "반복다중최적화(IMO) 모형"을 이용하여 탄소세 부과가 가격구조에 미치는 영향을 분석하였다. 분석 결과는 고정투입계수모형에 비하여 가격인상효과는 전반적으로 낮게 나타났으며, 특히 에너지집약산업은 고정투입계수모형에 비하여 가격상승률이 낮게 나타난 반면, 기타산업은 가격상승폭이 높게 나타났다. 이러한 결과는 에너지원에 대한 탄소세의 부과효과가 상대가격변화에 적응한 경제주체들의 비용최소화 노력으로 각 산업으로 분산된 결과라 여겨진다.

• Journal of Environmental Policy
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• v.5 no.4
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• pp.107-126
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• 2006

The voluntary agreement between industries and government on the recycling of wastes has been analysed. The agreement is one of the threatened voluntary agreements. Theoretically these agreements make it possible to fulfill recycling goals with minimized cost. It is the objective of this paper to evaluate the efficiency of the voluntary agreement on recycling wastes by examining of Nash Equilibrium. In the first place, the equilibrium of a bilateral agreement between the representative of industries (association of firms) and government will be analysed to confirm if cost minimization strategies by the association result in a sub-game perfect Nash Equilibrium. This is followed by an analysis of a multilateral agreement among the members of the association to see how the equilibrium and efficiency conditions change. We tried to find some implications that the result of the analysis casts on the environmental policy matters.

• Environmental and Resource Economics Review
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• v.6 no.1
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• pp.45-57
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• 1996

공기업(公企業)이 정부의 수익성사업이나 국가기간사업을 독점적으로 수행함에 있어 야기되는 X-비효율성 및 기술혁신의 결여, 사기업(私企業)의 경우와 달리 이윤극대화라는 단일 목적만을 추구할 수 없는 공기업(公企業)의 경영여건, 노사분규로 인한 요소사용비율의 변화, 그리고 각종 정부규제등 여러 제약된 여건하에서 생산요소의 비효율적 배분으로 인하여 생산비용의 최소화가 이루어지고 있다고는 볼 수 없다. 본 연구에서는 공기업(公企業)을 대상으로 실증적으로 시장가격의 함수인 암묵가격(暗默價格)(shadow price)을 설명변수로 사용하는 일반비용함수(一般費用函數)(generalized cost function)를 추정한 후, 효율성검정을 실시하여 생산비용의 최소화여부를 알아본다. 한국 전기업의 '88년 '93년의 2년간 10개 시 도별 자료를 사용하여 효율성검정을 실시한 결과, 생산비용의 최소화는 이루어지고 있지 않음을 알 수 있었다. 생산의 비효율성으로 인하여 비용은 평균 27.4% 증가되었으며 자본과 노동은 각각 적정수준보다 평균 10.6%, 2.1% 만큼 적게 사용된 반면, 연료는 255% 만큼 필요 이상으로 사용되었다.

• Journal of the Korean Institute of Gas
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• v.18 no.2
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• pp.81-86
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• 2014

The analysis of the cost optimization and the total demand weight of 9% Ni-steel plates for installing shell stiffeners in the side wall of the large capacity LNG storage tank are carried out in order to reduce the costs of the plates for stiffeners. This study can be possible for developing the calculation program which evaluates the bill-of-material for stiffeners to reduce the manual calculation time of tank designer, and to enable the estimation of weight and cost for various plate width. The results show that the demand weight and cost are reduced as the plate width is wider. Nevertheless, both the weight and the cost with plate width for stiffeners should be compared and evaluated to obtain the optimum cost time to time because of various cost incremental factors of plates such as transportation and handling cost, etc.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.450-453
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• 2004

본 연구는 리드타임이 상이한 다단계의 공급 사슬에서 수송비용과 재고비용을 최소화하는 다기간의 차량일정계획 수립에 관한 연구이다. 일반적인 공급사슬모형과 차량일정계획 문제를 통합한 모형으로서, 각 단계의 가용차량과 차량 용량이 제한된 제약조건하에서 비용을 최소화하는 차량일정을 구하는 문제이다. 본 연구에서는 이에 대한 최적화 수리모형과 2단계의 분할해법을 제시하였으며, 다양한 공급사슬모형에 대한 발견적 기법의 성능을 분석하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.149-158
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• 2019

The scheduling of planned maintenance problem of a system consisting of a number of components was studied. The purpose of maintenance scheduling is to minimize the cost of maintaining long-term operations. On the system side, the cost of a system shutdown can be minimized by grouping and inspecting a number of components. In addition, proper inspection cycles can be selected for each component to identify the failure sufficiently early to minimize the cost of the failure. To reduce the complexity of the calculations, the 'base interval approach' used in previous studies was applied and, in addition, the inspection cost savings from simultaneous inspections of multiple components were considered. To compare the effectiveness of inspection cost savings, this paper presents the results of simulation analysis performed by referring to the cases in the existing studies.

• Journal of Energy Engineering
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• v.6 no.2
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• pp.188-197
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• 1997

MARKAL model was applied for assessment of iron and steel technology for the year of 2032 considering cost and environmental effects based on 1992. Technology, energy and material flows were analyzed in iron and steel sector. Reference iron and steel system was designed according to this analysis. Six scenarios were developed considering cost and environmental limitations such as CO$_2$emission control and SOx reduction cost. Competitiveness of technologies in iron and steel sector was assessed under different environmental limitations with cost minimization. Through this study, it was confirmed that MARKAL model can be applied to technology assessment in the field of iron and steel industry.

• Journal of Korea Port Economic Association
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• v.26 no.3
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• pp.42-55
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• 2010

This paper primarily deals with a decision-making for determining the number of voyages in each ship size under a specific port structure in order to minimize the total transport cost consisting of transport cost at sea, queuing cost in port, and inventory cost in yard. As a result of computer simulation using queuing model characterized by inter-arrival time distribution, we were able to find out some combination of voyage numbers of 3 ship-size(50,000-ton, 100,000-ton, and 200,000-ton), where the total transport cost can be minimized under a specific port structure. The simulation model also allows us to figure out any trade-off relationship among sea transport cost, queuing cost in port, and inventory cost in yard. Put it differently, an attempt to reduce the sea transport cost by increasing the number of voyages of the largest ship size, the transport cost incurred in both port and yard is hypothesized to be increased and vice versa. Consequently, Port managers are required to adjust the number of annual number of voyages allocated in each ship size, put into the sea lines for importing raw materials, in order to optimize the transport costs incurred under the specific port system. We may consider a net present value(NPV) model for performing an economic feasibility analysis on port investment project. If a total discounted net benefit, including cost savings, exceeds the initial investment for an additional berth construction, then we accept the port investment project. Otherwise, we reject the proposed port investment plan.

• Proceedings of the Safety Management and Science Conference
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• 2013.11a
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• pp.99-104
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• 2013

비용편익분석은 어떤 사업으로 인하여 자연배분의 변화가 생길 때 그에 따른 경제적 편익을 측정하게 되며 사업을 시행하여 생기는 편익과 비용을 비교하여 경제성을 평가하고 대안 중에서 우선순위를 결정할 때 유용하다. 따라서, 본 논문은 자본에 관한 투자기준을 마련하기 위해서 분석용 모델인 "비용편익분석"을 활용 하여 제조기업의 어떤 사업계획에 의하여 생겨나는 자본요소가 어떻게 투자되어야 생산비용을 최소화 할 수 있는지를 자본투자에서 가장 핵심적인 생산설비투자와 기술개발투자에 대한 비용편익분석을 통하여 그 방법론을 제시함으로써, 자본투자에 있어서 "비용효과분석"의 활용성을 확인하고자 한다.