• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.223-225
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• 2001

When a wide area blackout occurres, reenergizing transmission lines should be done at first. The KEPCO(Korea Electric Power Corporation) divides whole power system grid Into seven subsystem. This paper describes the investigation of facts, such as voltage rising and system stability, which occur in case that the blackstart plant of the Honam area will be displaced from Juam H/P to Seojingang H/P.

• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.278-281
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• 2001

Identifying the fault location has to deal with multiple possible candidates. It presents a new technique to diagnosis a fault region. The proposed diagnosis scheme identifies accurately the location based on the protective device operations and load current change at the substation. An Expert system is presented using these facts.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.71-73
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• 2005

한국전력공사에서는 전압원 인버터형 FACTS 기기인 UPFC를 전남 강진군 강진변전소에 설치(2003. 5. 23준공) 운전하였다. 강진 UPFC는 한전과 (주)효성이 공동으로 투자하고, 지멘스와의 기술제휴를 통해 개발하였으며, 40MVA 병렬인버터, 40MVA 직럴인버터로 구성되어 총 80MVA 용량이다. 준공이후 2년여에 걸친 운전으로, 강진UPFC의 고장정지는 현저히 줄었다. 본 논문에서는 강진 UPFC의 주요 이벤트, 고장해소 및 설비의 신뢰성 향상을 위한 대응 조치들에 대해 정리하였다.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1785-1787
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• 2003

본 논문에서는 현재 대용량 전력변환 소자인 사이리스터는 해남-제주간의 HVDC변환소에 채용되어 운전중에 있고, BTB 및 SVC등에 채용되고 있으며, 향후 FACTS, 남북 전력계통연계, 동북아 계통연계 등 전력변환용으로 사용될 부품으로 사용범위가 날로 증가하고 있는 2,208개의 사이리스터의 수명 및 신뢰성을 평가하기 위해 고온직류 blocking 가속열화시험조건에 대해서 기술하였다.

• Korean Institute of Interior Design Journal
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• no.9
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• pp.24-29
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• 1996

The objectives of this study is to create an environment which students could apply effectively through focused on the innovative methods of education and CAD course contents. The facts which were able to figure out from this study were as follows ; 1. After the analysis of the CAD course contents of the american universities, their common contents were in order of introduce to Computer Aided Drafting and design with Auto CAD/ provide fundamental knowledge of the application for use in design/ examine and how this effects 2 D image and model creation/ CAD as a design tool . Over all trend of CAD course contents of interior design program in american university is moving toward utilizing CAD as a design tool. 2. On the other hand, common contents of our local universities were simply introducing CAD. It means that our course contents are more methodological and theoreatical . And american university's program is focused on problem solving solution as a design tool.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.211-213
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• 2005

한국전력공사에서는 전압원 인버터형 FACTS 기기인 UPFC를 전남 강진군 강진변전소에 설치(2003. 5. 23준공) 운전하였다. 강진 UPFC는 한전과 (주)효성이 공동으로 투자하고, 지멘스와의 기술제휴를 통해 개발하였으며, 40MVA 병렬인버터, 40MVA 직렬인버터로 구성되어 총 80MVA 용량이다. 준공이후 2년여에 걸친 운전으로, 강진 UPFC의 고장정지는 현저히 줄었다. 본 논문에서는 강진 UPFC의 주요 이벤트, 고장해소 및 설비의 신뢰성 향상을 위한 대응 조치들에 대해 정리하였다.

• The KIPS Transactions:PartD
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• v.8D no.4
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• pp.339-346
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• 2001

A problem for mining association rules under the interactive environments is to mine repeatedly association rules with the different minimum support. This problem includes all subproblems except on the facts that mine repeatedly association rules with the s믇 database. This paper proposed the efficient algorithms to improve the performance by using the information of the candidate large itemsets which calculate the previous association rules. The proposed algorithms were compared with the conventional algorithm with respect to the execution time. The comparisons show that the proposed algorithms achieve 10∼30% more gain than the conventional algorithm.

• Journal of Advanced Navigation Technology
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• v.13 no.5
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• pp.662-668
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• 2009

Design of IPI(Inverted PI) feeding internal antenna for the gain improvement of mobile phone was proposed. IPI feeding structure affects on both low radiation resistance of antenna and increase current for the internal antenna such as IFA(Inverted F Antenna). By these facts, antenna fed by IPI can get the gain improvement with increasing radiation efficiency. For the verification, we applied IPI feeding structure to conventional quad band IFA. Measurement shows that IPI-IFA has 0.3~2.0[dB] higher gain than conventional IFA on GSM/DCS/USPCS/WCDMA band.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.11a
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• pp.232-233
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• 2005

Stainless steel has been stably used closed by passivity oxidation films($Cr_2O_3$) is made by neutral atmospheric environment. However, passivity oxidation films of the surface of stainless steel occasionally comes to be destroyed in seawater which is influenced by an environment having halogen ion like $Cl^-$, then, localization corrosion comes to occur. Stainless steel 304 for shaft system material of the small-size FRP fishing boat on seawater environments made an experiment on simulation of sacrifical anode(Al, Zn). Through these experiment and study, following results have been obtained ; According to the field inspection and corrosion simulation, the corrosion on the 2nd class stainless steel shaft(STS 304) in FRP fishing boat has been verified to occur by crevice corrosion and galvanic corrosion etc.. According to the comparison and analysis of Stainless steel 304 shaft materials after simulation leaving unprotected and applying cathodic protection, unprotected shaft specimen of stainless steel 304 was severely corroded, but, protected shaft specimen was not totally corroded. This result is assumed to be made by the facts that anodic reaction, $Fe{\rightarrow}Fe^{2+}$ + $2e^-$, has been restricted by the cathodic protection current of sacrificial anode material.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.504-507
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• 2007

The KOMPSAT-2 satellite is a push-broom system with MSC (Multi Spectral Camera) which contains a panchromatic band and four multi-spectral bands covering the spectral range from 450nm to 900nm. The PAN band is composed of six CCD array with 2528 pixels. And the MS band has one CCD array with 3792 pixels. Raw imagery generated from a push-broom sensor contains vertical streaks caused by variability in detector response, variability in lens falloff, pixel area, output amplifiers and especially electrical gain and offset. Relative radiometric calibration is necessary to account for the detector-to-detector non-uniformity in this raw imagery. Non-uniformity correction (NUC) is that the process of performing on-board relative correction of gain and offset for each pixel to improve data compressibility and to reduce banding and streaking from aggregation or re-sampling in the imagery. A relative gain and offset are calculated for each detector using scenes from uniform target area such as a large desert, forest, sea. In the NUC of KOMPSAT-2, The NUC table for each pixel are divided as HF NUC (high frequency NUC) and LF NUC (low frequency NUC) to apply to few restricted facts in the operating system ofKOMPSAT-2. This work presents the algorithm and process of NUC table generation and shows the imagery to compare with and without calibration.