• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.7
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• pp.1047-1054
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• 2004

Internal defects in the glass, like-as micro-voids, micro-cracks, or inclusions, easily cause the failure when the glass is exposed to the shock or the thermal variation. In order to produce the highly reliable glass product, the precision inspection of the defect in the glass is required. For this purpose, this paper proposes a machine vision technique based on the auto-focusing method, which searches the defect and measures the location under the fact that the edge image of defect must be the most clear when the focal plane of CCD camera is coincided with the defect. As for the search index, the gradient indicator is presented. The basic principles are verified through the simulations for the computer-generated defect images, where the affects of defect shape, gray level of background, and the brightness of the defect image are also analyzed. Finally, experimental results for actual glass specimens are shown to confirm the applicability of this method to the actual field.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.302-302
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• 2011

수문 순환 및 물 수지에 관한 연구는 강수량, 지표유출량, 지하수, 토양수분 및 증발산량에 대한 정량화가 이루어질 때 실제적으로 규명될 수 있다. 그러나, 수문 순환 및 물수지 평가에 중요한 부분을 차지하는 증발산량의 경우 관측값보다 단순한 가정이나 경험식에 의한 추정값을 사용하고 있어 그 자료의 신뢰성에 대해서도 꾸준히 문제가 제기되어 왔다. 또한 수문 순환과 관련하여 실제 관측되고 있는 성분은 대개 기상 변수에 국한되어, 모형 검증에 필요한 증발산량 관측이 거의 없는 실정이다. 따라서 수문 순환 및 물수지의 정량적인 분석을 위해 수문 순환 과정에서 상당부분을 차지하는 증발산량의 측정이 필요한 실정이다. 본 연구는 국토해양부의 기초수문자료 구축사업의 일환으로 수행되었으며, 에디공분산 기술을 사용하여 한반도의 대표적 식생 기능 형태인 혼효림(설마천 유역, 2007년 8월부터)과, 논경지(청미천 유역, 2008년 8월 부터)에서의 증발산량 측정을 수행하였다. 그 결과 두 지점에서의 증발산량의 계절 및 연 변동 특성을 파악할 수 있었다. 혼효림(설마천 유역)에서 산정된 증발산량은 2008년 507mm, 2009년 440mm, 2010년 491mm이고, 논경지(청미천 유역)에서 산정된 증발산량은 2009년 554mm, 2010년 609mm의 값을 보였다.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.3
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• pp.237-243
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• 2007

Probabilistic seismic risk analysis was performed. Exceeding probabilities of combined stress and maximum horizontal displacement of steel piled pier due to surface ground motion which was transferred from base rock motion was expressed as seismic fragility curves. Occurrence probability of peak ground motion was calculated by using the seismic hazard map on design code for harbor and fishery structures of Korea. Finally seismic risk of pier structure was found by combining the fragility and the hazard and those were presented through numerical analysis.

• Science of Emotion and Sensibility
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• v.2 no.1
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• pp.147-155
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• 1999

온열쾌적감에 영향을 주는 중요한 요인들로는 온도, 습도, 기류 등의 물리적 요인과 성별이나 체질 등 뿐만 아니라 온열환경에서 느끼는 인간의 감성적인 측면도 요인으로 작용한다. 본 연구에서는 여러 가지 온열 환경 중에서 실내의 상하온도차와 기류방식의 제어에 따른 생체반응의 변화, 및 감성의 변화를 관찰하여 온열환경에 따른 인간의 온열쾌적감을 평가하기 위해 생리신호를 측정, 분석하였다. 인간에게 가장 쾌적함을 주는 최적의 실내 상하온도차와 기류제어방식을 구현하기 위한 평가방법으로 MST(mean skin temperature)분석 및 HRV(heart rate variability) 분석과 EEG 주파수 스펙트럼 분석을 시행하였다. 그 결과 실내의 상하온도차는 23$^{\circ}C$의 머리부위 온도에서 발 부위와의 온도차가 -3$^{\circ}C$일 때 가장 쾌적한 조건으로 나타났고, 기류제어방식은 감성기류조건에서 가장 쾌적함을 보였다. 본 연구를 통해 실내의 상하온도차와 기류방식에 대한 온열환경의 쾌적조건을 설정하였고, HRV 분석과 EEG의 주파수 분석이 주판신소설문평가와 유의한 결과를 나타내어 이러한 생리신호의 분석이 인간의 감성적 측면을 고려한 온열쾌적성을 펑가하는데 보다 객관적이고 신뢰성 있는 평가지표로 이용될 수 있음을 제시하였다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.3
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• pp.116-124
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• 2014

Penetration depth of inorganic waterproofing agent is difficult to assess quantitatively because inorganic waterproofing agent for concrete is not an internal waterproof membrane. However, evaluation of penetration depth of inorganic waterproofing agent is one of the most important evaluation index to secure efficiency in a consistent penetration. Therefore, this paper was proposed penetration depth measurement method of inorganic waterproofing agent for concrete and the penetration depth of the conventional inorganic waterproofing agent have been evaluated through the proposed penetration depth measurement method. As a result of test, the measured penetration depth throught the proposed penetration depth measurement method of inorganic waterproofing agent showed that more than 90% reliability.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.1
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• pp.9-14
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• 2018

This study describes the design and implementation of IMUX(Input Multiplexer) for Satellite Communication. The IMUX unit for SHF band consists of Combine Filter, Power Splitter, Isolator and Channel Filter. Through the pre-simulation analysis of space environment, the possibility of the malfunction of equipment minimized and we designed a reliable IMUX through simulation for vibration analysis generated during the launch, and compared pre-simulation of main performance results to test results about main performances of IMUX after production.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.2
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• pp.261-266
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• 2017

This study describes the design and implementation of SHF band Upconverter Digital Satellite Communication. The SHF band Upconverter unit consists of PLDROand frequency converter. In frequency converter, microstripBPF and LPF designed through the pre EMsimulation are implemented to minimize the unwanted spurious in frequency converter. Through the pre-simulation analysis ofspace environment, the possibility of and minimized about the malfunction of equipment and we designed a reliable SHF band Upconverter through simulation for a TID according to the vibration generated during the launch and space radiation environment, and compared pre-simulation of main performance results to test results about main performances of SHF band Upconverter after production.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.983-988
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• 2017

This study describes the design and implementation of OMUX(Output Multiplexer) for Satellite Communication. The OMUX unit for SHF band consists of LPF(Low Pass Filter), manifolder and Channel Filter. Through the pre-simulation analysis of space environment, the possibility of the malfunction of equipment minimized and we designed a reliable OMUX through simulation for vibration analysis generated during the launch, and compared pre-simulation of main performance results to test results about main performances of OMUX after production.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.1
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• pp.58-65
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• 2008

Reliability-Centered Maintenance plan for maintenance schedule of generating unit is being assessed in this paper. Maintenance schedule is a key index that can be used to determine stability and cost. In this paper, stochastic FMECA is described for the life assessment by using probability distribution, and combustion-turbine generations in Korean power systems have been assessed for maintenance schedule. Such an assessment can be a useful guide for maintenance plans in restructured power industry.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.6
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• pp.63-73
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• 2011

Travel speed is an important parameter for measuring road traffic. UTIS(Urban Traffic Information System) was developed as a mobile detector for measuring link travel speeds in South Korea. After investigation, we founded that UTIS includes some missing data caused by the lack of probe vehicles on road segments, system failures and etc. Imputation is the practice of filling in missing data with estimated values. In this paper, we suggests a new model for imputing missing data to provide accurate link travel speeds to the public. In the field test, new model showed the travel speed measuring accuracy of 93.6%. Therefore, it can be concluded that the proposed model significantly improves travel speed measuring accuracy.