• 한국정밀공학회지
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• 제30권5호
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• pp.467-473
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• 2013

Diverse approaches for reducing the total energy consumption of machine tools have been introduced and developed, to cope with rapid increase of total energy costs in world-wide manufacturing industries. To realize the improvement of the energy efficiency, systematic and integrated strategies must be considered, including energy-saving design, optimized control operation and concrete evaluation of the energy efficiency. This paper proposes key enabling technologies required to improve the energy efficiency of 5-axis multi-functional machining tools, considering both of system design and operation in the real production environments. Related standardized procedures of the energy efficiency evaluation is also represented.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1732-1750
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• 2010

Operation of KORAIL's level crossing is in charge of KORAIL. As taking over existing level crossing to KORAIL, they do not conduct risk assessments, so we do not know about any possibilities of inner risk. And present operation of safety of the level crossing is just regular checking of reaction and functions of safety equipments physically, we need to react to the changes of what's going on around of level crossing and incestigation of traffic flow and surrounding conditions more spontaneously. So, we have to prepare the strategies against accidents of level crossing cost-effectively based on regular risk assessments for sustainable safety improvements and overcome operational problems of present level crossing's safety. Here, we're going to investigate the level of safety level and present risk factors of the level crossing using risk assessments for accidents/error of the equipments to show operational strategies of level crossing based on risk assessments.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2001년도 봄 학술발표회 논문집
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• pp.375-382
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• 2001

This paper deals with the compensation method of AMD stroke by adopting variable gain feedback control strategy. The gains, generally known to be constant, are designed to have variable values according to the structural responses and the AMD stroke. This strategy has the advantage of compensating AMD stroke under any kind of loadings, on the other hand the conventional strategies work only under the specific loading. The strategy shows that the AMD stroke is compensated to prevent the stroke saturation and the control force is found not affected by the compensating operation while the control force is reduced and the control efficiency is decreased during the compensating operation in the conventional strategies.

• 한국기후변화학회지
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• 제9권4호
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• pp.313-318
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• 2018

The growth rate of international aviation is expected to be higher than that of most industries and the proportion of carbon emissions from the aviation industry will become very significant as the year 2050 approaches. Constraining the growth of this industry is not desirable because it is essential for human welfare as well as the development of related industries. However, reduction of carbon due to aviation is not easy because it is difficult to improve fuel efficiency in a significant way. The ICAO (International Civil Aviation Organization), which is the main organization responsible for handling this problem, developed a program named CORSIA (Carbon Offsetting and Reduction Scheme for International Aviation). The present study analyzes various strategies for countries and airlines to comply with CORSIA using a fuel-efficient system. We conclude that countries should improve their airspace utilization systems, airport facilities, and air navigation systems. Additionally, based on the results of a flight data analysis, airlines should improve their operational efficiency in terms of operations control, flight operation, and maintenance management.

• 한국산학기술학회논문지
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• 제18권6호
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• pp.653-661
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• 2017

본 논문은 탄소배출 규제와 같이 새롭게 변화하는 물류 환경에서 유통업체들이 올바른 물류전략을 선정하기 위하여 탄소배출을 고려한 두 물류전략의 총 운영비용의 비교 분석 연구를 수행하였다. 본 연구에서는 물류전략간 운영비용 비교를 위하여 기존 EOQ(Economic Order Quantity) 모형을 활용하여 국내의 물류환경 및 탄소배출을 고려한 모형으로 확장하였고, 이 모형을 바탕으로 실증연구 분석을 수행하였다. 실증 연구로는 대형 유통업체의 농산물 유통을 대상으로 하여 기존의 물류 전략과 직배송 물류 전략의 운영비용 및 경제적 주문량을 산정하고 분석하였다. 실증연구 결과 농산물을 운송함에 있어 직배송 물류전략이 기존 물류전략 대비 50% 이상의 운영비용 절감효과가 있는 것으로 분석되었고, 이는 직배송 물류전략이 기업의 운영비용 절감에 더 효과적인 것으로 판단할 수 있다. 결론적으로, 탄소배출을 고려하였을 때 직배송 물류전략이 기존 물류전략보다 경제적 환경적인 효과가 있다고 분석될 수 있으며, 농산물의 신선도도 함께 높이는 전략이라고 판단된다.

• Journal of Computational Design and Engineering
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• 제1권4호
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• pp.233-242
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• 2014

A magnetically levitated vehicle (Maglev) system is under commercialization as a new transportation system in Korea. The Maglev is operated by an unmanned automatic control system. Therefore, the plan of train operation should be carefully established and validated in advance. In general, when making a train operation plan, statistically predicted traffic data is used. However, a traffic wave often occurs in real train service, and demand-driven simulation technology is required to review a train operation plan and service quality considering traffic waves. We propose a method and model to simulate Maglev operation considering continuous demand changes. For this purpose, we employed a discrete event model that is suitable for modeling the behavior of railway passenger transportation. We modeled the system hierarchically using discrete event system specification (DEVS) formalism. In addition, through implementation and an experiment using the DEVSim++ simulation environment, we tested the feasibility of the proposed model. Our experimental results also verified that our demand-driven simulation technology can be used for a priori review of train operation plans and strategies.

• 한국지열·수열에너지학회논문집
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• 제16권4호
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• pp.1-8
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• 2020

For a central cooling system of a medical facility composed of absorption chiller and screw chiller, the study was conducted on how to minimize the energy cost. In consideration of the energy cost, the optimal operation method in which the operation method of the heat source is changed according to the size of the cooling load was derived through simulation analysis. When applying the optimal operation method, the indoor environment, energy consumption, and energy cost were analyzed and compared with the reference operation method.

• 한국ITS학회:학술대회논문집
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• 한국ITS학회 2005년도 제4회 추계학술대회 및 정기총회
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• pp.34-39
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• 2005

• 대한안전경영과학회지
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• 제6권2호
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• pp.49-65
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• 2004

Ministry of Environment developed ‘Emergency Response Information System (ERIS)’ in 2001, which is in operation. As a next step, currently National Emergency Response Information System (NERIS) is being developed. The main difference among ERIS and NERIS is to enhance the system in the national level, including transportation of hazardous materials. This paper introduces concepts and methods applied to NERIS, especially HAZMAT, and the information system, operating strategies. Based on GIS and transportation-network data, the best route can be offered using Risk Analysis. Strategies for reporting and first-response information systems are also designed for emergencies in the paper.

• 한국유통학회지:유통연구
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• 제1권2호
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• pp.85-114
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• 1996

The franchise system has become more widely adopted by Korean distribution industries than before as foreign direct investment is liberalized in these industries. However, a number of problems has arisen between franchisers and franchisees recently. In this regard, the objective of this study is to identify problems arisen between franchisers and franchisees of convenience store operation. More specifically, this paper investigates how credibility between two parties is affected by the internal political structures, including bureaucratic structure and relational norms, and impact strategies of franchisers. The results of this study can be summarized as follows : Under rapidly changing channel environment, credibility between franchisers and franchisees tend to be characterized as the bureaucratic structure rather than relational norms. This result suggests that franchisees are more likely to recognize the power of franchisers in Korean convenience stores. This paper also shows that the adoption of coercive impact strategies decreases credibility and vice versa. The results of this paper suggest following implications. In order to have mutually beneficial relationship franchisers and franchisees have to share benefits and costs incurred by their convenience store operation, and to raise their ability to revise contract terms to accommodate changes in external environments. It is also important for the development of convenience store operation to construct more efficient relationship between franchisers and franchisees by adopting supportive norms rather than opportunistic ones.