• 전기학회논문지
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• 제58권9호
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• pp.1706-1713
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• 2009

In this paper, a parallel operation algorithm for high power PEMFC generation systems is proposed. According to increasing the capacity of fuel cell systems with several fuel cell stacks, the different dynamic characteristics of each fuel cell stack effect on imbalance of load sharing and current distribution, so that a robust parallel operation algorithm is desired. Therefore, a power-sharing technique is developed and explained in order to design an optimal distributed PEMFC generation system. In addition, an optimal controller design procedure for the proposed parallel operation algorithm is introduced, along with informative simulations and experimental results.

• Journal of Electrical Engineering and Technology
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• 제5권2호
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• pp.246-254
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• 2010

This paper presents a multiagent system for microgrid operation in the grid-interconnected mode. An energy market environment with generation competition is adopted for microgrid operation in order to guarantee autonomous participation and meet the requirements of participants in the microgrid. The modified Contract Net Protocol (CNP) is used as a protocol for interactions among agents. The multiagent system for microgrid operation based on the modified CNP and the energy market environment is designed and implemented. To verify the feasibility of the suggested multiagent system, experiments on three operation conditions are carried out.

• Industrial Engineering and Management Systems
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• 제1권1호
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• pp.19-28
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• 2002

An operation sequence of parts is one of the most important production factors in the design of cellular manufacturing systems. Many similarity coefficient method (SCM) based approaches have been proposed to solve cell formation problems in the literature. However, most of them do not consider the operation sequence factor. This study presents an operation sequence ratio (OSR) and modifies some existing similarity coefficients using the OSR to solver cell formation problems considering operation sequences. The computational results show that the OSR ratio is useful and robust in solving cell formation problems with operation sequences.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 학술대회 논문집 전문대학교육위원
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• pp.153-157
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• 2002

Electricity living body formation operation appliance is using most imports until present. And, because electricity living body formation operation appliance is too expensive, it becomes burden to buy in small scale hospital. Also, problem that economical damage by income is added follows, Therefore, this treatise developed electricity living body formation operation appliance by home production, Ultra high frequency eruption circuit used LC circuit, and output frequency is possible to 8 [MHz], and output voltage amplified maximum 800 [V]. This operation appliance could display size of fixed current. This developed product could microscopic operation fewer than 1 [mm]. This development technology is considered by do metallic surface heat treatment, melting, welding, induction heating device and that can apply to domestic animals surgical operation and so on.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계합동학술대회 논문집
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• pp.127-132
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• 2002

Electricity living body formation operation appliance is using most imports until present. And, because electricity living body formation operation appliance is too expensive, it becomes burden to buy in small scale hospital. Also, problem that economical damage by income is added follows. Therefore, this treatise developed electricity living body formation operation appliance by home production. Ultra high frequency eruption circuit used LC circuit. and output frequency is possible to 8 [MHz], and output voltage amplified maximum 800 [V]. This operation appliance could display size of fixed current. This developed product could microscopic operation fewer than 1 [mm]. This development technology is considered by do metallic surface heat treatment, melting, welding, induction heating device and that can apply to domestic animals surgical operation and so on.

• 한국항공운항학회지
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• 제27권4호
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• pp.96-104
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• 2019

The response to climate change of international air transport industry might be initiated by ICAO's CORSIA (Carbon Offsetting and Reduction Scheme for International Aviation) which will impact on international airlines' flight operation behavior in the future. Though the airlines' efforts to reduce fuel consumption has been a major issue in economics of aviation industry, the improvement of fuel efficiency in flight operation will have additional impact on their profitability by introducing carbon emission cost. The fuel consumption in flight operation will be somewhat influenced by pilots' technical action for maneuvering aircraft during flight operation. This study will investigate pilots' behavior on decision for tactical aircraft control for mission flight. The data will be collected by the survey through sample pilots asking about their intention and perception on fuel savings during flight operations. The data will be analyzed by AHP process and the study will find out the elements and factors influencing pilots' behavior on technical decision of flight and their weights on fuel saving effects.

• 전기학회논문지
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• 제67권6호
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• pp.708-714
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• 2018

Islanded operation of a microgrid can ensure the reliable operation of the system when a large accident occurs in the main grid. However, because the generation capability of a microgrid is typically limited, a microgrid operator should take islanded operation risk into account in scheduling its generation resources. To address this problem, in this paper we have proposed two unit commitment formulations based on the islanding scenario that reflect the expected and worst-case values of the islanded operation risk. An optimal resource scheduling strategy is obtained for the microgrid operator by solving these optimization problem, and the effectiveness of the proposed method is investigated by numerical simulations.

• 전기학회논문지
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• 제67권6호
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• pp.738-744
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• 2018

This paper proposes a low cost hot swap operation circuit of a parallel operation power supply for servers. Hot swap function for server power system is essential in 24 hour operation system such as internet data center, server, factory and etc. Server power supplies used in internet data centers have two or more parallel operations with the hot swap operation. However, the cost of the power supply is high because the controller IC for hot swap operation is very expensive. Therefore, this paper proposes a parallel-operated power supply with a low-cost hot swap controller for servers. The proposed system can operate hot swap function by using discrete devices and reduce the cost by more than 50%. A 1.2kW prototype system is implemented to verify the proposed low cost hot swap controller.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2004년도 춘계종합학술대회
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• pp.784-787
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• 2004

타원곡선 암호시스템에서의 가장 줄기가 되는 연산은 스칼라 곱셈 연산이다. 본 논문에서는 기존의 두배점-덧셈 (double-and-add) 알고리즘으로 처리하였던 스칼라 곱셈 연산을 개선하여 네배점-덧셈(fund-and-add) 알고리즘을 사용하기 위하여 네배점 (point quadruple) 연산을 유도한다. 유도된 식은 C 프로그램을 사용하여 실제 계산에 응용하여 증명하였다. 네배점 스칼라 연산은 타원곡선 암호시스템의 효율적이고 빠른 연산을 처리하는데 응용될 수 있다.

• 전기학회논문지
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• 제65권7호
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• pp.1115-1120
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• 2016

This paper presents the daily load forecasting for special days considering the rate of operation of industrial consumers. The authors analyzed the power consumption pattern for both the special and ordinary days according to the contract power classification of industrial consumers, and selected 400~600 specific consumers for which the rates of operation during special days are needed. Load forecasting for 2014 special days considering the rate of operation of industrial consumers showed a noticeable improvement on forecasting error of daily peak demand, which proved the effectiveness of the survey for the rates of operation during special days of industrial consumers.