• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1900-1902
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• 2000

In this paper, the temperature distribution and thermal stress analysis of mold transformer for power distribution system is investigated by FEM. Filler type epoxy is applied for good cooling effect in mold transformer.

• 대한수학회보
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• 제46권1호
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• pp.107-116
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• 2009

We consider a single server multi-class queueing model with Poisson arrivals and relative priorities. For this queue, we derive a system of equations for the transform of the queue length distribution. Using this system of equations we find the moments of the queue length distribution as a solution of linear equations.

• 산업경영시스템학회지
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• 제20권44호
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• pp.61-68
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• 1997

The algorithm of customer demand decomposition suggested by this study is a reconstruction method of distribution network under the allowance of same level supply. Regional distribution center(RDC) distributes additional inventories of some of the supplying items to retailers under its charge to reduce the time needed for emergency delivery to neighborhood retailer where backlog happened. This also restrict the purpose of the inventories held by RDC as only regular supply. All of which leads to the creation of more realistic method allowing the affiliation of closing related RDC with one in the vicinity. In this study, the role of RDC is restricted only as supplying items regularity and the conruction of distribution system processing through the closing by consideration of the possibility of supplying retailers from the RDC in the vicinity is discussed.

• 조명전기설비학회논문지
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• 제14권3호
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• pp.22-28
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• 2000

본 논문에서는 산업용 수변전 계통의 전기적 특성을 PTW(Power Tools for Windows)를 이용하여 종합적으로 분석하기 위한 기법올 제시했다. 케이블의 정.영상 임피던스는 T&D(Transmission and Distribution)와 BICC규정등을 수변전설비에 적합하게 수정 적용하였고, 변압지의 X/R 자료는 IEEE 표준자료를 이용하였다, 이러한 기법은 실제 운전 중인 2개의 공장올 모델로 전력조류계산, 고장계산 및 과부하시 전통기의 과도특성 등을 분석하여 그 효율성을 입증하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전력기술부문
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• pp.151-153
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• 2006

This paper describes the transient phenomena considering transformer model in combined distribution systems with power cables. To evaluate the overvoltage, the change of transformer model and system structure are considered. Transformer parameters calculated by BCTRAN of EMTP are considered to evaluate surge generation in underground distribution systems when underground distribution system has various parameters. It is evaluated that overvoltage value increases and decreases according to the structure of system. However it is confirmed that there is not much effect to overvoltage as transformer is operated in distribution line.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 하계종합학술대회 논문집
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• pp.712-717
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• 1989

A communication system through distribution lines was developed for distribution automation. Since all facilities in distrbution systems are connected by distribution lines, economical communication systems can be realized by using these lines as data transmission lines. But it has a problem in transmission reliability bcause of its sensitivity to noise and impeadance. Therefore, to cope with this problem. measurement and analysis of the communication characteristics are made according to the influence of load impeadence change, signal level and noise generated in load. Field tests were carried out at Kyung Ki branch of the KEPCO for half year starting in Feburary 1988.

• 산업경영시스템학회지
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• 제17권31호
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• pp.59-72
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• 1994

This paper deals with ordering policies of consumable goods which have large demand rates in a multi-level distribution system. The system we are concerned consists of one Central Distribution Center(CDC) and N non-identical Regional Distribution Centers(RDCs) which have different demand rates, minimum fillrates, leadtimes, etc. The customer demand on the RDC is stationary poisson and the RDCs demand on the CDC is superposition of Q-stage Erlang distributions. We approximate the RDCs and CDC demand distribution to nomal in order to enhance the efficiency of algorithm. The relevant costs include a fixed ordering cost and inventory holding cost, and backorder cost. The objective is to find a continuous-review ordering policy that minimizes the expected average costs under constraints of minimum fill rates of RDCs and maximum allowable mean delay of CDC. We developed an algorithm for determining the optimal ordering policies of the CDC and the RDCs. We verified and compared the performance of the algorithm through the simulation using the algorithm result as the input parameters.

• 전기학회논문지P
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• 제67권3호
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• pp.119-124
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• 2018

Recently, LVDC distribution network and DC microgrid with many advantages are being built. However, this LVDC distribution is an IT grounded or ungrounded system, and it is difficult to detect a ground fault because the fault current is small. In this paper, we propose a signal injection method for unipolar LVDC distribution network to detect ground fault in ungrounded LVDC distribution, and various analyzes were performed for ground fault detection.

• 정보처리학회논문지A
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• 제12A권5호
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• pp.405-412
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• 2005

혈액 유통 과정에서 여러 가지 문제들이 빈번히 발생하고 있다 현행 혈액 유통 과정을 알아보고, 유통 과정의 문제점을 파악하여 근본적인 해결 방안이 필요하다. 본 논문에서는 혈액 유통 과정의 여러 가지 문제점들을 해결하고, 체계적인 혈액 관리를 위해 RFID 시스템을 도입하고자 한다. 다양한 RFID 시스템 종류들 중에서 혈액 유통과정에 적합한 Reader와 Tag를 설계하고, 정보의 DB화를 통한 전자 태그의 구분과 이를 이용해 오브젝트 설계 및 혈액 유통 RFID(Radio Frequency Identification) 시스템 설계를 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전력기술부문
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• pp.315-318
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• 2002

The use of high-temperature superconducting materials for transmission cable application is being realized in prototype situation. HTS cable systems have been installed in laboratories and tested successfully around the world. In korea. the first step in development of superconducting cables is distribution system. In this paper. it is proposed the HTS distribution system modeling using ATPDraw and EMTDC programs. In the multilayer conductor, the inner layers have higher impedance than the outer layers. As a result, the current concentrate$ in the outer layers. This paper presents the result of the current distribution in EMTDC.