• 전기학회논문지
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• 제66권6호
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• pp.885-891
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• 2017

The energy storage system(ESS) is a core component for exchanging the power system structure of the unidirectional power flow into a bidirectional structure. Its important role has been increasing because it has multiple functions such as output stabilization of new renewable energy, demand management, frequency regulation, etc. However, the performance evaluation technology of ESS in korea is lower than one of advanced countries and the recognition of standardization is also lack compared to advanced countries. Furthermore, in order to more accurately and reliably validate the performance of the ESS in advanced countries, it has been required to perform not only performance testing by H/W devices but also performance verification by S/W tool. Therefore, in order to verify the performance testing of ESS by S/W tool, this paper proposes the modeling method of performance testing devices for MW scaled ESS by using the PSCAD/EMTDC S/W, based on real testing devices in domestic institute. From the simulation results of proposed modeling method, it is confirmed that the proposed modeling method is a useful tool for performance validation of ESS.

• 비파괴검사학회지
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• 제30권4호
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• pp.317-323
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• 2010

원자력발전소 배관 용접부에 대한 수동 초음파검사는 KPD(Korean Performance Demonstration)의 일반 절차서를 사용하여 기량 검증을 인정받고 있으나, 자동 초음파검사의 경우에는 일반 절차서가 없으며 해당 자동 검사 장비를 이용하여 절차서 기량 검증을 받아야 한다. 현재까지 국내에서 수행되고 있는 자동 초음파검사에 대한 절차서 기량검증은 대부분 펄스-반사기법을 적용한 절차서이나, 최근에 각광받고 있는 위상배열 초음파검사 기법을 이용한 절차서 기량검증은 국내에서 시행된 사례가 전무하다. 본 연구에서는 원자력발전소 가동중검사에 위상배열 초음파검사 기법을 적용하기 위하여 위상배열 초음파 신호취득 및 평가 소프트웨어를 개발하고 위상배열 초음파 탐촉자 및 웨지를 설계 하였다. 개발된 절차서에 대하여 결함 검출, 길이 및 크기 측정에 대한 기량검증을 수행하였으며, 검증된 위상배열 초음파탐상검사 절차서는 향후 원자력발전소 배관 용접부 검사에 적용할 예정이다.

• 응용통계연구
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• 제10권1호
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• pp.177-187
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• 1997

고정효과가 하나인 이원혼합모형에서의 고정효과 유의성검정에 대한 검정력 분석을 고려한다. 고정효과 수준간의 차이를 검정하는데 사용되는 일반화 최소제곱 F 통계량을 헨더슨의 방법 III, 사전추측값이 1인 MINQUE 추정량, 최우추정법, 제한적 최우 추정법을 이용하여 구하고 이 검정 통계량들의 검정력을 모의실험을 통하여 알아본다. 모의실험의 결과는 결론적으로 검정력의 측면에서 살펴본 효율성은 4가지 추정량 모두 대체적으로 비슷한 것으로 판명되었다.

• 한국신뢰성학회지:신뢰성응용연구
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• 제17권2호
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• pp.136-142
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• 2017

Purpose: In this paper, we propose a test method for evaluating the life time of the inverter which is one of the main internal configuration systems in order to evaluate the life time of the power supply for the vehicle. Methods: The performance and failure criteria required for the development of the accelerated life test method were established and the Taguchi method was used to derive the stress factors affecting performance and reliability. Results: The major stress of the product degradation were considered to be high temperature. Conclusion: The acceleration factor was estimated through a two-level high temperature test and a test methods was designed to guarantee the accelerated life time of the inverter.

• 한국압력기기공학회 논문집
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• 제11권2호
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• pp.13-19
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• 2015

Steam generator is one of the most important component of nuclear power plant, and it's integrity and reliability are to be assured to high level by pre-service inspection and in-service inspection. To improve the reliability of steam generator heat exchanger tubes and to secure the management of nuclear power plant safely, KHNP CRI recently has developed eddy current testing system for steam generator. KHNP CRI have performed a series of experimental verification and field application to confirm the performance of the developed ECT system in accordance with ASME Code requirements. The ECT system consists of a remote data acquisition unit, an ECT signal acquisition and analysis software, a water chamber robot controller and a probe push-puller. In this paper, we will details of the developed ECT system and the software and their experimental performance. And also we will report the field applying performance and the issues for further steps.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 추계학술대회 논문집 전력기술부문
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• pp.122-124
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• 2008

Korea Electric Power Research Institute has being carried out an IEC 61580 communication service test on IED trial products developed related to power IT project "The verification of Performance of the Substation Automation System and Its Field Test". This paper describes control testing, one of the IEC 61850 conformance testing items, which consists of DO, enhanced DO, SBO and enhanced SBO with a number of test cases.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권3호
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• pp.1393-1405
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• 2017

It is well known that duty-cycling control by dynamically adjusting the polling interval according to the traffic loads can effectively achieve power saving in wireless sensor networks. Thus, there has been a significant research effort in developing polling interval adaptation schemes. Especially, Dynamic Low Power Listening (DLPL) scheme is one of the most widely adopted open-looping polling interval adaptation techniques in wireless sensor networks. In DLPL scheme, if consecutive idle (busy) samplings reach a given fixed threshold, the polling interval is increased (decreased). However, due to the trial-and-error based approach, it may significantly deteriorate the system performance depending on given threshold parameters. In this paper, we propose a novel DLPL scheme, called SDL (Sequential hypothesis testing based Dynamic LPL), which employs sequential hypothesis testing to decide whether to change the polling interval conforming to various traffic conditions. Simulation results show that SDL achieves substantial power saving over state-of-the-art DLPL schemes.

• 비파괴검사학회지
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• 제29권2호
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• pp.145-152
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• 2009

국내 원전 가동중검사 기술은 대부분이 선진국에서 도입한 비파괴검사 장비를 진단현장에 적용하는 운영기술로 지금까지 선진 운영 기술의 습득에 중점을 두어, 검사 시스템 하드웨어 및 소프트웨어의 국내 제작 기술은 매우 미흡하였다. 때문에 국산 고유모델의 원전 가동중검사용 진단장치 개발의 필요성이 끊임없이 제기되었다. 본 연구에서는, 원전 배관 자동 초음파검사 시스템의 핵심 기술인 고성능 다채널 초음파 펄서/리시버와 A/D converter 보드, 디지털 제어보드를 개발하고 그 성능을 검증하였다. 검증 실험 결과는 개발된 시스템이 설계 목적에 부합하는 성능을 보이는 것으로 확인되었다.

• 한국유통학회지:유통연구
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• 제1권1호
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• pp.109-127
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• 1996

The purpose of this study was to represent hypotheses of the interrelationship of the level of cooperation, conflict, and performance and to report the findings testing the hypotheses in car channels. This study provides some general guidance toward better cooperation, conflict, and performance management. The results indicate that noncoercive bases of power and dependence hale a positive effect on cooperation, while the proposed inverse relationship between coercive bases of power and cooperation is not statistically significant. Coercive bases of power have a positive effect on conflict, while conflict is not statistically significant for noncoercive bases of power, dependence, and cooperation. Finally, cooperation has a positive effect on dealer performance, but conflict has a negative effect on dealer performance.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.35.2-35.2
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• 2011

A wind turbine power performance test is very important to wind turbine manufacturers because a wind farm developer or planner must want to define power performance characteristics and reliability of new wind turbines. Based on the IEC 61400-12-1, A wind turbine test site has to be nicely installed at flat terrain for testing. We are developing the wind power system which is IEC wind class IIa model with rated power of 3MW. KEPCO's Gochang power testing center was considered as candidates to build the test site without site calibration. This paper aims to verify the validity of the test site by using implement site assessment result that was based on IEC 61400-12-1.