• KEPCO Journal on Electric Power and Energy
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• v.2 no.4
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• pp.543-548
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• 2016

Live-line maintenance for electric power lines is very dangerous because of their ultra-high voltage environments and the risks of falling from heights. Recently, drone technology has been spotlighted due to its maneuverability and stable controllability, and has been being applied to maintenance works in the electric power industry. This paper presents a new type of drone that can be transformable by introducing biomimetics to its mechanism and can run on an overhead ground wire as well as it can fly. Its technical feasibility was confirmed through experiments.

• Korean Institute of Interior Design Journal
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• no.25
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• pp.130-134
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• 2000

The purpose of this study is to identify the perceptual differences among independent elderly relative to falls risk associated with specified environmental design factors. The sample consisted of 135 independent elderly who live in Ulsan. The data were collected by utilizing questionnaire which included demographic information, and environmental design assessments accompanied by line drawings. The data were analyzed by using SAS program. The major findings were as follows: (1) There were 35(25.9%) elderly experienced fall(s) within one year and about half of the fallers fell more than once. (2) The elderly perceived lighting is the most hazardous interior design factor related to increased risk of falls. (3) There was a significant difference among age groups on perception of lighting factors and the elderly perceived floor factors differently by their perceived health status.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.375-376
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• 2008

송전선로에 절연물로 사용되는 애자는 설치 이후 장시간 사용에 따라 고전압 스트레스, 기계적 스트레스, 열 및 환경 스트레스 등으로 열화가 진행되기 때문에 안정적인 전력설비 운영을 위하여 활건 애자 비파괴 열화 상태 점검이 필요하다. 본 연구에서는 비파괴 상태 진단 감시 기술인 주파수 응답 함수 측정을 통한 고유 진동수 분석을 통하여 현재 활선 애자로 사용되고 있는 NGK210, KRI210, NGK300 및 KRI300 4가지 종류 애자의 동특성 실험을 수행하였으며, 이를 통하여 애자의 결함이 발생하였을 때 고유진동수 변화를 분석하였다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.7
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• pp.14-21
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• 2015

Distribution systems are operated in radial structure, but temporal loop structure could be founded the live load transfer. Main purposes of reconfiguration of distribution network are load balancing, loss minimization and voltage drop maintaining. In the loop structure, huge loop current can be flowed between two substations in case of large voltage angle difference. Protection devices of distribution line can be triped by this huge loop current. So, precise calculation of loop current is very important for secure switching. This paper proposes a novel calculation method of loop current using the voltage angle differences measured at the tie switches. Feasibility of the propose method has been verified by various case studies based on Matlab simulation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.9-15
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• 2016

Distribution networks are operated in radial fashion during the normal state. Loop configuration is also required temporally in case of live load transfer among the adjacent feeders. Voltage angles of each substation buses are very important data in order to calculate power flow of the loop structured distribution feeders. This paper proposes substation bus voltage angle calculation method using voltage angle difference measured at the normally open tie switches. Simulation case studies using Matlab simulink have been performed to establish feasibility of proposed method.

• Proceedings of the KSR Conference
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• 2006.11a
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• pp.239-252
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• 2006

The existing track structure for urban Maglev system is designed for the Maglev vehicles of HSST in Japan and UTM in Korea. The tracks hvaing cross beams for supporting rails are located on bridge girders and have several draw backs. Linimo in Nagoya, Japan, the first commercial urban Maglev line, has separated tracks from a bridge to overcome the previous track structure. However, the Linimo just put the existing track on bridge deck. This study suggests a improved track structure for urban Maglev system and compares the behavior of the new and existing track through static structural analyses. In the improved track, the power collector of a Maglew vehicle is installed parallel to the bridge deck surface, and, thus, the bottom width of the track structure is not limited by the vehicle's width. Therefore, the live load is distributed more effectively by the wide bottom of the track. Also, steel plates instead of steel cross beams are used to support rails, and, thus, the rail's deflection is improved.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2005.05a
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• pp.51-54
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• 2005

In the contemporary, all social shifts as well as the fields of design have been changed much faster than past. And continually it will be changed in the future. In this situation, futuristic design will be much more important paradigm than now. Emotion and digital can be key issues in the futuristic design paradigms. Karim Rashid is one of most famous futuristic designers, and all his works are expressed emotion and digital. Also he uses various factors to express futurism such as curved line, futuristic colors, special materials, and so on. In the future, we will live in the emotion and digital culture age. According to social shifts, our life should be change with Futurism. Therefore his role will be more important, and he has to consider relationship between men and their surroundings as he designs all his work's range, specially housing design.

• Proceedings of the KIEE Conference
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• 2007.04b
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• pp.20-23
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• 2007

활선작업시 개폐섬락전압은 철탑형태와 작업유형에 따라 개폐섬락전압이 달리 나타나게 된다. 즉, 활선작업자의 위치, 철탑 종류 및 애자장치 종류 등에 따라 개폐섬락전압은 다르게 나타나기 때문에, 적용하고자 하는 활선공법이 있다면, 이에 대한 개폐섬락전압의 특성을 파악해 둘 필요가 있다. 점퍼V련은 일반적으로 선로의 수평각이 중각도 지역에 설치된다. 즉, 수평각이 너무 커서 조립식 점퍼장치를 설치할 수 없는 철탑에 점퍼V련 장치를 설치한다. 765kV 송전선로에서 실제 점퍼V련 장치가 많이 설치되어 있지 않으나, 이 경우에도 유지보수 사항이 발생할 수 있기 때문에 안전한 활선작업을 위한 실규모급 개폐섬락특성에 대해 검토할 필요가 있다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05a
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• pp.18-22
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• 2000

The partial discharge testing is widely used in insulation property measurement because it gives low stress to high voltage equipment which is undertaken tests. Therefore it is very useful method compare to previous destructive methods and effective diagnosis method in power transformer that requires live-line diagnosis. But partial discharges have very complex characteristics of discharge pattern so it is required continuous research to development of precise analysis method. In recent, the study of partial discharge is carrying out discover of initial defect of power equipment through condition diagnosis and system development of degradation diagnosis using HFPD(High Frequency Partial Discharge) detection. In this study, simulated transformer is manufactured and HFPD occurred from transformer is measured with broad band antenna in real time, the degradation grade of transformer is analyzed through produced patterns in simulated transformer according to applied voltages.

• Journal of Microbiology and Biotechnology
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• v.16 no.10
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• pp.1513-1517
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• 2006

One single lactic acid producing bacterium, isolated from kimchi, inhibited the growth and adherence of Helicobacter pylori to the human gastric epithelial cell line MKN-45. This isolate was identified as Lactobacillus plantarum and termed L. plantarum strain PL9011. The adherence of H pylori, in the presence of live or nonviable L. plantarum strain PL9011 (10-fold CFU), decreased to 14-20%. The spent culture supernatant of L. plantarum strain PL9011 resulted in the eradication of H pylori. This activity remained stable following neutralization and heat treatment, but not following pepsin treatment, thereby suggesting small peptides as the inhibitory factor. L. plantarum strain PL9011 did not produce any harmful metabolites or enzymes. The results obtained in this study suggest that the L. plantarum strain PL9011 may be a potential novel probiotic for the stomach.