• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.447-450
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• 2005

The purpose of this study is to investigate properties of compressive strength of concrete using the shale rock as coarse aggregates. To evaluate properties of compressive strength of concrete using crushed shale rock, we performed the expriment according to the proportioning strength of $10MPa\~40MPa$ and the slupm of $12\%\~15\%$. The result of this study is as follow. The compressive strength of concrete using crushed shale rock is lower than those of granite aggregates. The proportioning strength is higher, the reduction of comperssive strength of concrete using the shale rock is higher.

• Journal of the Korean Ceramic Society
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• v.43 no.1 s.284
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• pp.28-32
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• 2006

Diarylethene in photochromic materials was doped in organic-inorganic hybrid low-melting glasses were synthesized through a nonaqueous acid-base reaction process, which consists of network units including a small number of bridging oxides. The organic phase is a dichlorodimethylsilane while the inorganic phase is a tin(II) chloride. Diarylethene was incorporated into the glasses without any degradation of its functionality. The open form of diarylenthene, which is converted from the opening one upon UV-irradiation, is change to the closed form visible light-irradiation. The rate constant of the photochemical reaction is $31.78\times10^{-3}s^{-1}$ with 400 W UV lamp irradiation.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.561-564
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• 2008

$Ba_{1-x}M_xGa_2S_4:Eu^{2+}$ (M = Ca, Sr) phosphor was prepared for white light emitting diodes application. Photoluminescence (PL) emission and excitation bands were red-shifted with increase of Ca and Sr content due to the crystal field effect. Moreover, the PL intensity under 450 nm was increased by substitution of Ca and Sr.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.653-655
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• 2015

The nodes of Ad-hoc network are made up of location registration for sending informations and a great number of packet transmissions to maintain routing route among the nodes. Under this environment, a huge number of traffics would be generated as mobility variable occurs more than in physical network. Hence, in this paper, focused on to study the relationship of nodes to analyze the extent of the traffic in order to control the traffics of the multi-hop in Ad-hoc.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.44-46
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• 2002

Service restoration following a complete or partial collapse starts with reenergize a transmission line from black-start generators. Voltage problems can arise by Ferranti effect as unloaded transmission line is reenergized. This paper presents analytical results on the primary restorative transmission system focused on the voltage problem during the early restoration process. Methodologies to handle load pick-up compensating Ferranti effect. and terminal voltage and reactive capability limitation of black-start generators about self-excitation are presented. An algorithm for static analysis about these methodologies is developed, and EMTDC simulation for verifying the efficiency of the algorithm is performed.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1864-1866
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• 2001

최근 배전계통에서는 전력공급 신뢰도 향상을 위해서 평상시 및 사고시의 전압/전류를 신속하고, 정확하게 계측할 수 있는 광계측 방식의 적용이 적극적으로 진행되고 있다. 본 논문은 이러한 것을 배경으로 하여 배전용 광 CT 및 PT의 국산화 모델의 선정, 시제품 제작 및 특성시험의 결과에 대해서 기술하였다.

• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.113-115
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• 2000

So far, it was very difficult to simulate the dispersed generation system including PV generation system using EMTP or EMTDC because the source of the dispersed generation system has a particular VI characteristic equation. In this paper, a novel simulation method of PV generation system has proposed and a new solar cell component for EMTDC is also developed. The VI characteristic equation of solar cell is used in order to realize the solar generation system in EMTDC simulation. Consequently the simulation of PV power generation system using field data is realized and acceptable results, which show close match between the real data of PV panel and the simulated data, were obtained.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1447-1449
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• 1999

The KEPCO is developing the load forecasting system using land-use simulation method and distribution planning system. A distribution planning needs the data of present loads, forecasted loads and substations. distribution lines information. By the distribution planning system, the distribution line designer determines the substations and feeder lines plan. This paper presents the method of formulation process for the long term load forecasting and optimal distribution planning, and describes the case study of long term distribution planning of Suwon-city according to the newly applied method.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2304-2306
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• 2004

This paper proposes an Intelligent Speed Estimator in order to realize the speed-sensorless vector control of an induction motor. Intelligent Speed Estimator used Model Reference Adaptive System which has Fuzzy-Neural adaptive mechanism as Speed Estimation method. The Intelligent Speed Estimator estimates the speed of an induction motor with a rotor flux of a reference model and adjustable model in MRAS. The Intelligent Speed Estimator reduces the error of the rotor flux between the voltage flux model and the current flux model using the error and the change of error as input of the Estimator. The computer simulation is executed to verify the propriety and the effectiveness of the proposed speed estimator.

• The Bulletin of The Korean Astronomical Society
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• v.34 no.2
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• pp.30.2-30.2
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• 2009