• 전기의세계
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• v.42 no.7
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• pp.9-17
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• 1993

전기 이중층 커패시트의 원리, 구조, 제조공정 대표적인 제품의 특성 및 응용에 대하여 개략적으로 살펴보고자 한다. 국내의 경우도 콘데서 제조사에서 개발하고 있는 것으로 알려져 있으나 아직 출시되고 있지는 않은 실정이다. 전자기기의 백업 전원, 태양전지 발전시스템의 보조 전원, 전기 차량의 전원 및 기타 각종 백업 전원으로 기존의 전지보다 우수한 성능의 디바이스가 강하게 요구되는 국내 실정을 감안할 때 전기 이중층 커패시터로의 대치 방안도 좋은 해결책의 하나가 될 것으로 판단되어 소개하는 바이며 이 분야 연구, 개발이 활성화 되기를 기대한다.

• KIPE Magazine
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• v.8 no.6
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• pp.16-20
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• 2003

본 특집원고에서는 분산전원이 기존의 배전계통에 도입될 경우, 보호방식측면에서 야기될 수 있는 문제점에 대해서 현장의 배전실무자들이 간단히 개략적으로 이를 검토분석 및 해석할 수 있는 방법을 소개하기로 한다. 이를 위하여 먼저, 기존 배전계통과 분산전원 연계배전계통의 보호방식상의 특징을 설명하고, 분산전원이 도입된 연계배전게통의 보호방식상의 문제점을 평상시와 비정상시로 나누어 제시하고, 이를 보호방식상의 문제점에 대한 대책을 각각 제시하기로 한다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.655-656
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• 2007

전력 계통에 연계형 분산전원이 도입되므로 인하여 기존배전선로와 달리 양방향 전력조류가 발생, 이에따른 보호계전방식의 수정을 필요로 하므로, PSCAD-EMTDC 시뮬레이터를 통하여, 이때의 배전계통의 현상들을 모의하고, 이에 따른 대책을 제시하므로 하여 배전계통 신뢰도를 향상시키기 위한 연구를 진행하였습니다. 기존선로를 이용해 연계된 분산전원과, 전용선로를 통하여 연계된 분산전원을 모의하고, 부하 상태와 사고 형태에 따른 시뮬레이션을 진행 현상을 분석하여 새로운 운영방식을 제시하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.06a
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• pp.407-413
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• 2009

외국산제품의 수입에만 의존하던 항로표지용 전원일체형 소형 LED 등명기(Self-powered LED Lantern)를 국내 처초로 개발하여 제작하고 시험을 통해 그 성능을 확인하였다. 이에 외국에서 생산되는 제품들의 동향과 국내 최초로 개발된 항로표지용 전원일체형 소형 LED 등명기(Self-powered LED Lantern)의 주요 특징 및 성능을 소개한다.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.19-20
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• 2014

본 논문에서는 왜곡된 단상 전원 전압 하에서도 교류 입력 전류를 정현적으로 제어할 수 있도록 하는 제어기법을 제안하였다. 단상의 물리량을 가상의 삼상 물리량으로 변환하여 이를 d-q축 동기좌표계로 변환된 물리량으로 제어하는 동기좌표계 전류제어기법을 적용하였으며, 왜곡된 전원 전압에 의한 왜곡된 위상각 성분을 추출하여 이를 d-q축 동기좌표계 지령전류에 보상하는 방법을 제안하였다. 제안한 기법으로 왜곡된 전원 전압 하에서도 교류 입력 전류의 고조파를 5%이내로 제한할 수 있음을 시뮬레이션을 통하여 확인하였다.

• Neonatal Medicine
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• v.18 no.1
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• pp.137-142
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• 2011

Purpose: In relation to perinatal healthcare, medical institutions and resources are limitative and also are in a state of flux due to the therapeutic specialty. We analyzed requests for interhospital transfers received by Busan 1339 Emergency Medical Information Center (EMIC) to grasp the state of perinatal healthcare delivery system. Methods: This study was conducted on the basis of data inputted into the computing system of Busan 1339 EMIC, between January 1 and December 31, 2009. In connection with 378 pregnant women and 136 newborns who were required to transfer, retrospective analyses were made of the success rate of transfer (SR), the number of contacted hospitals, the time required for transfer and the reason of transfer and refusal. Results: In the case of pregnant women, the SR were 65.5%. They came in contact with 2.7 hospitals, and it took 24.4 minutes. As for the reason of transfer, preterm labor accounted for the highest proportion. In the case of newborns, the SR were 71.3%. They came in contact with 2.4 hospitals, and it took 15.6 minutes. The most common reason of transfer were respiratory symptoms. In the reason of refusal with pregnant women and newborn, the lack of medical staff, medical equipments and wards accounted for great. Conclusion: Many pregnant women and newborns have been transferred to hospitals by EMIC, but the SR has not been higher yet. Accordingly, there is a need to evaluate the propriety of perinatal treatment system, as well as to set up effective perinatal healthcare delivery system.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.1
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• pp.91-97
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• 2011

The purpose of this study was to evaluate RPM maintenance in X-Smart according to the power supplied by the AC adapter and rechargeable battery. Five new X-Smart were used in this study. A handpiece with rubber disk which has reflective tape was mounted on the vice. To measure the RPM, a non-contact type digital tachometer was used. RPM measurements were recorded every 5 minutes to 180 minutes and repeated 3 times per motor from each power source. To evaluate a difference of the RPM changes, two-way repeated measures were performed using $SPSS^{TM}$ 14.0. All tests were conducted at the 95 percent confidence level. There was no significant difference in the RPM change between the power sources. Continuous use of X-Smart with a rechargeable battery for up to 180 minutes could be safely used as an endodontic wireless motor with a reliable RPM maintenance.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.6
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• pp.730-736
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• 2014

Test standards for electrical and electronic equipment required for ship operations is applying the IEC-60533 standard. However, although a test procedure and a specified regulation are clearly defined in the deck and bridge zone and general power distribution zone, they are not regulated in the special power distribution zone with ship propulsion system. For these reasons, the costs for additional research and development have been invested. In this paper, we was measured power noise in a special power distribution zone in ship and we were compared and analyzed values measured. The actual experiments are performed on the ship of Korea Maritime and Ocean University. As a result, the acquired data on Hanbada shows that loop antenna with low frequency band(160kHz) and ultra log antenna with high frequency band(1.97GHz)occur about 6-8dB differences and about 8.7 difference respectively. Also, the acquired data on Hannara shows that each loop antenna of 1MHz, 11MHz, and 25MHz occurs about 7dB difference about 4-5dB differences respectively. so standard of Special distribution zone must be specified by comparative analysis of data obtained by the experiment more.

• The Journal of the Convergence on Culture Technology
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• v.6 no.1
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• pp.155-162
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• 2020

We extracted the meaning of educational experience of the parents who moved to rural village for their children's education. While moving to the cities for the childen's education is general trend, moving to the rural village for the children's education is peculiar phenomenon. For the study, in-depth interviews were conducted with six parents who moved to rural village, and the statements were analyzed by the phenomenological analysis method of Colaizzi. As a result, thirty themes, eight theme clusters, and three meaning categories were extracted. Three categories which characterize the experience of parents who moved to rural village for their children are 'longing for nature-friendly life in rural area', 'positive experience of communication and empathy with neighbors', and 'children's happiness-centered education'. Eight theme clusters are 'dislike confined environment of an apartment', 'positive experience of childhood in the countryside', 'value direct and indirect experiences of variety', 'free and stimulating environment of countryside', 'experience of communicating and empathizing with neighbors','regret private education caused by parents' greed', 'value child centered education', 'yearn for the self-directed learning around character and art-physical abilities'. Based on the result, implications were discussed and follow-up studies were suggested.

• Environmental and Resource Economics Review
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• v.28 no.2
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• pp.201-229
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• 2019

This paper estimates the effects of generation mix changes in the $7^{th}$ and $8^{th}$ Basic Plan for Long-term Power Supply and Demand from two aspects: economic efficiency through electricity prices and environmental performance through $CO_2$ and air pollutants(NOx, SOx, PM) emissions. Particularly, we examined additional generation mix conversion paths that take into account the trade-off between economic efficiency and environmental performance through scenario analysis. According to our results, the conversion from the $7^{th}$ plan to the $8^{th}$ plan should increase the electricity prices in the mid- and long-term, while reducing GHG and air pollutants emissions at the same time. The alternative generation mix that combines $7^{th}$ and $8^{th}$ plans shows that there exists a path to mitigate the trade-off between economic and environmental in the long-term. It will be next to impossible to derive a optimal generation mix that simultaneously considers the core values, such as supply stability, environmental performance, economic efficiency, energy safety and energy security, when establishing the power supply and demand plan. However, by exploring the effects of various generation mix paths and suggesting near-optimal paths, people can best choose their direction after weighhing all the paths when deciding on a forward-looking generation mix in the long term.