• Proceedings of the Korean Reliability Society Conference
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• 2000.04a
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• pp.55-61
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• 2000

본 연구에서는 열화시스템의 교체정책을 결정할 때 열화에 의한 시스템의 성능의 저하로 인한 제품의 품질 특성치와 목표치(target value)와의 차이를 손실함수를 통해 비용으로 반영하여 교체정책을 제시하였다. 비용함수에는 검사비용, 교체비용, 손실비용이 포함되며, 이 비용들을 최소화하는 교체정책이 제시되었다. 또한 교체정책 결정 시 고려되는 열화에 의한 특성치의 변화, 검사비용, 열화추세 등의 변화에 따른 총비용의 변화와 상호관계를 실험을 통해서 관찰하였고, 실험결과 시스템의 특성에 따라 총비용을 최소화하는 최적검사주기가 존재함을 알 수 있다. 열화에 의한 특성치의 변화가 교체주기와 비용의 변화에 크게 영향을 주는 것으로 나타난 반면 검사비용은 정책결정에 큰 영향을 주지 않는 것으로 관측되었다. 손실함수의 도입을 통해 품질 특성치와 목표치와의 차이로 인한 비용을 줄일 수 있으며 이는 교체주기의 감소경향을 나타낸다.

• International Journal of Highway Engineering
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• v.13 no.4
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• pp.167-175
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• 2011

Evaluation of fuel consumption for the various road condition and vehicle type is necessary to perform the economic analysis of road construction which is important for the efficient design and management of road. Economic analysis of road should consider the social cost which can be divided into agency cost including initial construction expense, maintenance cost, and so on, and user cost consisting of vehicle operating cost, congestion cost, etc. Since vehicle operating cost depends on the traffic volume, fuel consumption that is a major part of vehicle operating cost will change by traffic volume as well. Fuel consumption is significantly affected by vehicle speed and road condition, especially the roughness. Thus, fuel consumption should be evaluated in terms of road condition, which is not currently considered. In this study, the estimation model of fuel consumption for the passenger cars in Korea has been developed by considering the road condition. First, the relationship between vehicle speed and fuel consumption that is used to calculate the vehicle operating cost for investment evaluation of transportation facility and the initial feasibility study of road construction was investigated. Second, with the consideration of road roughness, fuel consumption of the passenger car was measured. From the measurement, it was found that fuel consumption increased by $80m{\ell}$ per 100km driving as the roughness increased by 1m/km. Therefore, it is recommended that for the economic analysis of road design and management, the fuel consumption should be a function of road roughness.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.5
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• pp.1165-1171
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• 2015

Due to the increasing trend of operation and maintenance cost (O&M cost) of infrastructure, the accurate estimation of O&M cost is crucial part to the government. Recent literatures pointed out that gradual climate changes such as average temperature changes, average precipitation changes, and etc. have significant impact on infrastructure O&M cost. This research is intended to develop a long-term O&M cost prediction model of road facilities by considering the impacts of average temperature changes. For this end, the climate change scenarios of Intergovernmental Panel on Climate Change (IPCC)'s $5^{th}$ report are adopted to structure the impact of average temperature changes by using binomial lattice model. The proposed framework is expected to regional government in supporting decisions for road O&M cost.

• Environmental and Resource Economics Review
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• v.12 no.2
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• pp.299-325
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• 2003

This study uses Conrad's model(nominal fishing effort) of a fishery to analyze theoretically the effects of cost changes on fishing effort, harvest level, and stock size. Static and dynamic open access effects are also modeled present value maximizing scenarios through simulations, and compared an extended model, Cunningham's model(diminishing fishing effort). Results show that an increase in the unit cost of effort goes up the fish stock in static open access, but open access dynamics shows the exhaustion of fish stock as the unit cost of effort decreases. In conclusion, we can derive the optimal equilibrium of resource, given conditions and parameters, as well as utilize this comparative statics to efficient fishery management.

• Journal of Korean Society of Transportation
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• v.16 no.1
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• pp.7-24
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• 1998

1960년대 이후 경제규명의 괄목할 만한 성장과 생산규모가 확대되어 비용 최소화를 통한 물류분 야의 근대화가 핵심적인 문제로 대두됨에도 불구하고 체계적이며 효율적인 물류체계의 부재로 인한 물 류비의 상승은 산업경쟁력을 약화시켜 물가상승등의 경제불안을 초래하고 있다. 또 가중되는 도시내 교 통혼잡과 최근들어 시행되고 잇는 도시내 화물차량에 대한 각종 규제로 물류비중 수송비의 비증은 지속 적으로 증가되고 있는 실정이다. 이에 따라 사회적으로 물류비를 절감시킬수 있는 물류시설에 관한 관 심이 고조되고 있으며 국가나 지방자치 단체 차원에서도 지역간의 물류거점으로서의 유통단지나 복합화 물터미널 등에 대한 필요성이 강조되고 있는 실정이다. 그러나 이러한 지역간 물류거점으로서 체계뿐만 아니라 도시내에서의 물류활동 즉 도시내에 위치한 최종소비자를 대상으로한 수·배송은 도시교통문제 와 물류서비스를 최종적으로 실행과 직결되어 있다는 점에서 매우 중요한 의미를 갖는다. 따라서 본연 구에서는 도시내 물류거점 시설인 배송센타를 대상으로 배송센타 1일 가동시 총물류비용 모형을 도출하 여 1일 총물류비용을 최소화 할 수 있는 배송센터 최적수 결정 모의 실험 모형을 구성하였다. 이와 병 행하여 최근 들어 대형화물차량에 대한 도심진입규제 통행제한 등 각종 화물차량 규제로 인하여 배송행 태 변화에 따른 사례를 상정하여 민간 차원에서 규제후 변화된 물류비의 변화정도와 그비용을 감소시킬 수 있는 방안의 검토를 시행하였다.

• Journal of Korea Port Economic Association
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• v.26 no.1
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• pp.172-194
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• 2010

External costs emerge as a consequence of negative external effects. The EU commission and national government in Europe made themselves the internalization of external costs and began to make various measures. The traffic sector plays an important role. At the same time, it affects as financial loads to logistics service providers and carriers in Europe. This study examines current development in european logistic market conditions. It describes the reaction of different market players and stakeholders in the logistic value chain in EU, Switzerland and Germany. A portfolio of different strategic answers to the changing market environment is being developed. Therefore, different options for the internalization of external costs are proposed. This study finally derives propositions for future research.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.533_534
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• 2009

본 논문에서는 수요반응(Demand Response) 프로그램 적용 시 각 소비자의 부하패턴 변화에 따른 계통운영자(Independent System Operator : ISO)의 총 발전비용 변화량을 Shapley Value를 이용하여 각 소비자가 총 발전비용 감소에 기여한 정도를 파악할 것이다. 또한 사례연구를 통하여 수요반응 프로그램에서의 각 부하패턴 변화 유형에 따른 총 발전비용 감소에 대한 기여도 및 Shapley Value 적용 전후의 결과를 비교 분석하였다.

• ICROS
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• v.10 no.3
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• pp.17-20
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• 2004

정유 및 석유화학, 철강산업계는 제품수요의 변화, 에너지 및 원료단가 상승, 운전비용 상승 및 환경 규제 강화 등 다양한 주위 상황 변화로 인하여 기존 프로세스의 최적운전을 통한 비용절감이나 친환경적 운전이 매우 중요한 이슈가 되고 있다. 공정 개선을 통해서 이러한 문제를 해결하기 위한 방안으로는 새로운 설비를 도입하거나 기존 설비를 고치거나 기존의 공정 설비 및 장치를 최대한 이용할 수 있도록 조업 조건을 설정해 주는 방법 등이 있다. 그 중 비용 측면에서 유리하며 짧은 시간 내에 공정의 생산성을 향상시킬 수 있는 방법은 환경변화에 맞춰 공정이 유연하게 대처하도록 최적의 조업을 유지하는 것이다.(중략)

• Journal of Environmental Policy
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• v.9 no.1
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• pp.31-55
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• 2010

This study aims to estimate potential climate change damage in Korea using the PAGE model. This study reviewed previous a reasearch to compare relative sensitivity to climate change in Korea and other regions to generate climate change damage function. It was found that sensitivity to climate change in Korea is similar to other Organization for Economic Cooperation and Development (OECD) countries. This study estimated climate change impact for three scenarios. If no action is taken, climate change damage cost in Korea could reach US$ 12,928 ~ 57,900 M. Cumulative Net Present Value (NPV)of climate change impact from 1990 to 2100 would be between US$ 143,226 ~ 921,701 Mdepending on emission scenarios. However, this result should be interpreted with caution as it draws its damage function based on only a few available references. Results also showed that an adaptation policy could decrease the degree of climate change impact significantly. If an adaptation policy is implemented, climate change impact will be decreased by US$ 11,355 million dollars in Korea in 2100.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.8
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• pp.1843-1849
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• 2009

In real-time 3D Graphics, pipeline optimization is one of techniques enhancing rendering performance. Pipeline optimization is kind of buffer reordering problem, but it is NP-hard. Therefore techniques that is approximating optimal solution and suitable for real-time 3D graphics are needed. This paper analyze pattern of rendering states changing costs for real-time 3D graphics, and based on this, the algorithm that brings rendering states into line by changing costs is proposed. The proposed technique shows good performance enhancement when costs of some rendering states are much higher than others. Proposed technique shows 2.5 to 4 times better performance than non-ordering algorithm and becomes more faster when rendering costs of a state gets higher.