• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전력기술부문
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• pp.174-177
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• 2003

Kinds of most frequent faults happened on overhead distribution system are the single line-to-ground fault, the line-to-line fault and the two line-to-ground fault. Occasionally, the three line-to-ground fault and the disconnection of a wire are happened in severe conditions. In this study, the single line-to-ground fault, the line-to-line fault, two line-to-ground fault on three-phase four-wire overhead distribution system were experimentally simulated and characteristics of total leakage current of distribution arrester caused by these faults were investigated. Also, the changing aspect of total leakage current of distribution arrester caused by voltage variation was investigated. In a consequence, abnormal voltages caused by voltage variation, the line-to-line fault, the two line-to-ground fault have a little effect on total leakage current of ZnO arrester. But abnormal voltages caused by the single line-to-ground fault have an important effect on total leakage current of ZnO arrester.

• 전기의세계
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• 제23권1호
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• pp.49-51
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• 1974

지금까지 대부분 전자계산기를 사용코저 하는 사람, 즉 user가 직접 전자계산소에 가서 service를 요청하면, 계산소에서 필요한 처리를 하여 그 결과를 용지에 인서하여 user에게 수도하는, 즉 off-line batch처리방식이 위주였다. 그러나 KIST등 일부에서는 중앙의 전자계산소와 통신선으로 연결된 user의 원격단말장치(remote terminal)에 의하여 user가 직접 계산소에 가지 않아도 이 단말장치에서 service를 받을 수 있는 on-line방식이 시도되었으며, 최근에는 대한항공회사의 항공좌석예약 on-line real time system과 외환은행의 은행창구업무 on-line real time system의 개발이 결실을 보기에 이르러, 우리나라에서도 이제 본격적인 정보사회의 모습을 갖추게 될 단계에 다달하게 되었다. 따라서, 여기서는 on-line real time system의 개념을, 이 방면에 관한 지식이나 상식이 없는 회원을 위하여 되도록이면 쉽게 해설코자 한다.

• 수산해양기술연구
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• 제34권2호
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• pp.139-143
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• 1998

In the fishing process on the sea eel pots, the most dangerous and difficult labor is manually separating process of several thousand pots from main line with high speed hauling operation. In this study, the automatic separating system of the pot from main line is developed. This system is composed with the clip connected to the pot by branch line, the keeper attached to the main line by pressing and the separator separating the clip and the keeper. In the experiment, static and dynamic characteristics of the system are investigated. From the considerations on the experimental results, it is ascertained that the automatic separating system of the pot from main line proposed in this study has good operating performance.

• 한국시뮬레이션학회논문지
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• 제11권4호
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• pp.69-80
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• 2002

This study deals with the productivity improvement on a flow production system with the consideration of line-balancing. In a flow production system, similar product models are produced on a same assembly line, the predefined process order and the limitation of total worker number. The system can be increased the work-in -process(WIP) inventory and the worker's idle time. In this study, the worker assignment model is developed to assign evenly workload of process to each product model in such a manner that each process has the different number of worker. This worker assignment model is the mathematical model that determines worker number in each process such that the idle time of processes is reduced and the utilization of worker is improved. We use a simulation technique to simulate the production line proposed by the mathematical model and apply real production line. With the result of simulation, this study analyzes the propriety of production line and proposes the alternatives of new production line

• 대한공간정보학회지
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• 제17권2호
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• pp.123-131
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• 2009

21세기 정보통신기술은 다양한 공간정보를 온라인으로 전송할 수 있는 수준에 이르고 있으며, 컴퓨터를 이용한 출력기술도 품질면에서 인쇄와 대등한 위치에 이르렀다. 이와 더불어 지도 사용자들 역시 다양한 공간정보를 온라인 상에서 직간접적으로 취득하길 원하고 있다. 그럼에도 불구하고 우리나라의 지형도 공급시스템은 오프라인 형태를 유지하고 있어 온라인 형태의 선진국에 비해 재고관리, 신속성, 경제성면에서 비효율성을 나타내고있다. 본 연구에서는 효율적인 지도공급시스템을 구축하기위해 현 공급체계의 문제점을 분석하고, 사용자요구지도제작, 온라인 결제 및 판매, 재고관리, 메타데이터구축, 보안모듈 등을 개발하였다. 개발된 시스템을 평가한 결과 기존의 방식에 비해 지도공급 및 관리의 효율성이 향상되었으며 사용자요구지도의 제작이 가능해졌다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권1호
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• pp.8-15
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• 2004

In order to scheme the optimal assumption that satisfies the travel demand, it should be review the elements that affect on determining the headway, which are signal systems, line shape, vehicle(Light Rail Transit) performance, and so on. When applying the conventional signal systems, including Fixed Block System and Moving Block System, It was confirmed whether or not satisfy the requirements of target line with the way of a numerical formula reviewing and Train performance Simulation on the main line, station, depot, and so forth. Therefore, it should be used as references that decide target line and each sub-system after identifying the compliances for Minimum Headway to Moving Block System.

• 대한전기학회논문지
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• 제41권5호
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• pp.459-467
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• 1992

This paper presents a new algorithm for the countermeasure to alleviate the line overloads due to contingency without shedding loads in a power system. This method for relieving the line overloads by line switching is based on obtaining the kine outage distribution factors-the linear sensitivity factors, which give the amount of change in the power flow of each line due to the removal of a line in a power system. There factors are made up of the elements of sparse bus reactance matrix and brach reactances. In this paper a fast algorithm and program is presented for obtaining only the required bus reactance elements which corresponds to a non-zero elements of bus admittance matrix, and elements of columns which correspond to two terminal buses of the overloaded(monitored) line. The proposed algorithm has been validated in tests on a 6-bus and the 30-bus test system.

• 한국전기전자재료학회논문지
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• 제23권2호
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• pp.148-152
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• 2010

The superconducting fault current limiter (SFCL) applied into the neural line of a power system, which can limit the unsymmetrical fault current from the single-line ground fault or the double-line ground fault, was reported to be the effective application location of the SFCL in a power system. However, the limiting operation for the symmetrical fault current like the triple line-ground fault is not effective because of properties of the balanced three-phase system. In this paper, the limiting method of the symmetrical fault current in a power system with a SFCL applied into neutral line was suggested. Through the short-circuit experiments of the three-phase fault types for the suggested method, the fault current limiting and recovery characteristics of the SFCL in the neutral line were analyzed and the effectiveness of the suggested method was described.

• 한국컴퓨터정보학회논문지
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• 제11권2호
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• pp.275-283
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• 2006

프로그램 저작물의 지적재산권 보호를 위해 저작자는 프로그램 심의조정위원회에 등록하여 저작권을 보호 받는다. 프로그램 등록은 off-line과 on-line으로 처리되고, on-line을 통한 프로그램 등록은 프로그램 등록자의 편의성 제공과 함께 저작물을 외부의 저작권 침해요소로부터 보호한다. 그러나, 등록된 저작물의 무결성과 기밀성은 내부의 위험요소(시스템 오류, 내부 관리자 불법접근 및 수정)에 보장 받지 못하는 단점이 있다. 본 논문에서는 저작물 기밀성 무결성 보증과 다중서명메커니즘을 이용하여 내부의 시스템 오류 및 내부자에 의한 저작물 침해요소로부터 신뢰된 저작물을 보장하고, 전자서명 관리의 편의성을 제공하는 시스템을 제안한다.

• Journal of Electrical Engineering and Technology
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• 제13권3호
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• pp.1079-1088
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• 2018

A line overload emergency control strategy based on the source-load synergy coefficient is proposed in this paper. First, the definition of the source-load synergy coefficient is introduced. When line overload is detected, the source-load branch synergy coefficient and source-load distribution synergy coefficient are calculated according to the real-time operation mode of the system. Second, the generator tripping and load shedding control node set is determined according to the source-load branch synergy coefficient. And then, according to the line overload condition, the control quantity of each control node is determined using the Double Fitness Particle Swarm Optimization (DFPSO), with minimum system economic loss as the objective function. Thus load shedding for the overloaded line could be realized. On this basis, in order to guarantee continuous and reliable power supply, on the condition that no new line overload is caused, some of the untripped generators are selected according to the source-load distribution synergy coefficient to increase power output. Thus power supply could be restored to some of the shedded loads, and the economic loss caused by emergency control could be minimized. Simulation tests on the IEEE 10-machine 39-bus system verify the effectiveness and feasibility of the proposed strategy.