• 조명전기설비학회논문지
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• 제24권7호
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• pp.9-19
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• 2010

Fuel cell (FC) distributed generation (DG) is gradually becoming more attractive to mainstream electricity users as capacity improves and costs decrease. New technologies including inverters are becoming available to provide a uniform standard interconnection of DGs with an electric power system. Some of the operating conflicts and the effect of DG on power quality are addressed and investigated through simulations on a real distribution network with an FC power plant. The results of these simulations have proved load tracking capability following the real and reactive power change of the load and have shown the flow of overcurrent from an FC power plant during the ground fault of a distribution line.

• 전기학회논문지
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• 제59권12호
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• pp.2190-2194
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• 2010

Wind power generation system (WPGS) of Ulleung Island causes frequency and voltage fluctuation due to wind speed variation during night time. Superconducting magnetic energy storage (SMES) system can overcome the fluctuations through the fast response time of energy charging and discharging. The SMES system should be connected to the terminal of the WPGS for frequency stabilization. To demonstrated the effectiveness of SMES system for power quality improvement, Ulleung Island power network was modeled in a real time digital simulator (RTDS). The RTDS-based simulation results of power quality improvement with SMES are investigated and discussed in detail.

• 한국산업정보학회논문지
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• 제6권3호
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• pp.44-50
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• 2001

정보기술의 활용은 비단 컴퓨터 커뮤니케이션 분야만이 아니라 생산/제조관리 시스템에도 활용되고 있다. 본 논문에서는 생산관리 시스템중 부품관리에 요구되는 품목의 코드화와 부품을 3차원 촬영으로 디지털화하는 장치의 개발을 다룬다. 촬영된 이미지는 웹 상으로도 제시되어 원격지에서 볼 수 있으며 이를 이용하면 원격지에서도 교육 및 훈련에 이용될 수 있다. 본 장치의 활용범위는 생산현장의 부품관리 이외에도 전자상거래, 사이버 전시, e-trade등에 적용가능하다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.37-39
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• 2003

This paper Presents an effective modeling scheme of high temperature superconducting transformer. So far there were numerical modeling and designs for conventional transformers for various applications. Recently, the interest and the R&D in superconducting technology and devices such as superconducting generator, motor, cable, fault current limiter and transformer have been increased gradually. With those interests, this paper proposes a simulation model of high temperature superconducting transformer using PSCAD/EMTDC, which can be applied to the utility network simulation readily under various system conditions.

• 조명전기설비학회논문지
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• 제21권9호
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• pp.81-86
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• 2007

Electric utility companies have the responsibility of providing good electricity for their customers. They have introduced the DAS(Distribution Automation System) to automate the power distribution networks. DAS engineers require state-of-the-art applications, such as a way to actively manage the distribution system and gain economic benefits from a flexible DAS architectural design. The existing DAS is not capable of handling these needs. It requires operator intervention whenever feeder overloading is detected while operator error could cause the feeder overload area to be extended. It also utilizes a closed architecture and it is therefore difficult to meet the system migration and future enhancement requirements. This paper represents a web based, platform-independent, flexible DAS architectural design and active database application. Recent advanced Internet technologies are fully utilized in this new DAS architecture allowing it to meet the system migration and future enhancement requirements. By using an active database, the DAS can minimize the feeder overloading area in the distribution system without operator intervention, thereby minimizing mistakes due to operator error.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2002년도 학술대회논문집
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• pp.139-145
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• 2002

Recently, power-electronics equipments or machine that microprocessor is included and computers have been installed continuously in industrial process or region of electronics customer. So concern for power quality, especially sags has been increased. Because those equipments are very sensitive to sags. The sag is phenomenon that magnitude of load voltage temporarily decreases because of power system fault. If a certain equipment in industrial process have any trouble result from sag, it can cause utility to be charged for enormous economics loss. Therefore it need to analyze the characteristic of sag and then mitigation method for sags in distribution system in odor to increase reliability. This paper gives an overview of sags characteristic due to short circuit fault in distribution system and after a general discussion of the various forms mitigation, gives a sags mitigation method with concentrating on changing the distribution system like spot network, on-site generation.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2012년도 춘계학술논문집 2부
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• pp.516-519
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• 2012

산업 현장에 필수적으로 사용하는 유틸리티 시스템(Utility System)의 하나인 에어를 생산하는 공기압 축기의 운전방식은 조작 패널부에 사용자가 설정한 셋팅값에 의해 내부의 밸브를 제어하여 로딩 및 언로딩 운전을 한다. 이로 인해 대용량(100HP, 200HP)의 공기압축기를 여러대 사용하는 수용가에서는 연속 다발적인 운전으로 인한 전력 사용량의 변동으로 역률 저하 및 연속가동으로 인한 설비 과부하 및 내부 기계 베어링 피로도 증가 및 파손 등 고장이 발생되는 문제점이 있다. 따라서 본 논문에서는 인공 신경회로망(ANN:Artificial Neural Network)을 이용하여 최적의 에너지 운용 알고리즘을 제안하여 실계통의 문제점을 분석하여 개선하고자 한다.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2011년도 한국컴퓨터종합학술대회논문집 Vol.38 No.1(A)
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• pp.352-354
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• 2011

The performance of multihop cognitive radio networks (CRN) can be improved significantly by using multiple channels in spectrum underlay fashion. However, interference due to the sharing of common radio channel and congestion due to the contention among those flows that share the same links become an obstacle to meet this challenge. How to control efficiently congestion and allocate power optimally to obtain a high end-to-end throughput is a key objective in this work. We reexamined the Network Utility Maximum (NUM) problem with a new primary outage constraint and proposed a novel resource allocation strategy to solve it effectively and efficiently.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.497-499
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• 2006

There are several types of communication method which is used for the supply of electric power stably. But the communication methods used in KEPCO have weak points in the viewpoint of economy, technology and management. The Satellite communication systems have competitive power in price and technology for national wide utility owing to its wide area coverage and stability. This paper presents various adapted examples of the Power industry using he satellite communication systems.

• Journal of Communications and Networks
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• 제12권2호
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• pp.181-190
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• 2010

A multitude of overlay network designs for resilient routing, multicasting, quality of service, content distribution, storage, and object location have been proposed. Overlay networks offer several attractive features, including ease of deployment, flexibility, adaptivity, and an infrastructure for collaboration among hosts. In this paper, we explore cooperation among co-existing, possibly heterogeneous, overlay networks. We discuss a spectrum of cooperative forwarding and information sharing services, and investigate the associated scalability, heterogeneity, and security problems. Motivated by these services, we design Synergy, a utility-based overlay internetworking architecture that fosters overlay cooperation. Our architecture promotes fair peering relationships to achieve synergism. Results from Internet experiments with cooperative forwarding overlays indicate that our Synergy prototype improves delay, throughput, and loss performance, while maintaining the autonomy and heterogeneity of individual overlay networks.