• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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• pp.137-140
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• 2003

Shorted-turns can have significant effects on a generator and its performance. Shorted-turn sensor for synchronous generator's field winding have been developed. One of effective method detecting inter-turn short circuits on round rotor winding is a method using sensor detecting. But the method needs duplicate design of sensor for characteristic change according to types and forms of generator Thus sensing skill without sensor depend on change of electric property in generator. For the reason, this paper presents shorted-turns phenomenon and the characteristic analysis of shorted-turns In synchronous generator by using 2-D finite element method(FEM).

• Transactions on Electrical and Electronic Materials
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• 제7권2호
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• pp.87-89
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• 2006

We investigated the current limiting characteristics of flux-lock type superconducting fault current limiter(SFCL) according to inductance variation of coil 2. The flux-lock type SFCL consists of two coils. The primary coil is wound in parallel to the secondary coil through an iron core, and the secondary coil is connected to the superconducting element in series. The operation of the flux-lock type SFCL can be divided into the subtractive and the additive polarity winding operations according to the winding directions between the coil 1 and coil 2. The current limiting characteristics in two winding directions were dependent of on the ratio of the number of turns of coil I and coil 2. The fault current increased when the number of turns of coil 2 increased in the subtractive polarity winding. On the contrary, the fault current decreased under the same conditions in case of the additive polarity winding.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제50권3호
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• pp.115-121
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• 2001

This paper deals with the electrical insulation design of a gas insulated power transformer based on extra turns method satisfying the impulse test performed in the worst condition. The calculation of electrical strength in insulation structure was done by 2D finite element method. The gas insulated power transformer was manufactured by selecting the optimum arrangement among design results. the validity of the design result is verified by the impulse test of manufactured machine.

• KIEE International Transactions on Electrophysics and Applications
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• 제5C권3호
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• pp.124-130
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• 2005

In this paper, we designed a cylindrical type light source having an electromagnetic principle of inductively coupled plasma, and measured its electrical-optical properties. Using the transformer principle, an electrically equivalent circuit cylindrical type light source was analyzed. According to the parameters of electromagnetic induction, which were diameter of coil with cpO.3$\~$ 1.2mm, number of turns with 4$\~$ 12 turns, distance with 40$\~$ l20mm and RF power with 10$\~$ 150W, the electrical .md optical properties were measured. When the diameter of the coil was cp0.3mm, number of turns was 8 and distance was 40mm, and the maximum brightness of 29,730 cd/m$^{2}$ was shown with RF power l50W. The relationship between electromagnetic induction and plasma discharges was demonstrated using the mode transition from E-mode to H-mode

• 전기학회논문지
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• 제57권6호
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• pp.982-984
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• 2008

This paper suggests anon-isolated high-gain boost converter using voltage-stacking cell. The voltage gain can be increased by adjusting number of voltage-stacking cells and transformer turns-ratio. Test results with 1kW prototype converter show that the voltage gain is three or four times higher than conventional boost converter at unity transformer turns-ratio and about 90% of efficiency is recorded under full load condition.

• 한국자기학회지
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• 제6권3호
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• pp.179-188
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• 1996

spiral 패턴과 meander 패턴의 공심 평면 인덕터에 대해 주파수, 도체간격, 도체폭, 턴수등을 변화시켜 저항, 인덕턴스와 같은 전기적인 특성치의 이론적인 예측에 대해 검토하였다. 도체폭이 커짐에 따라 저항과 인덕턴스는 감소한다. 이때 Q는 spiral pattern에서는 최대치를 가지는 도체폭이 존재하는 반면 meander pattern에서는 저항의 감소가 인덕턴스의 감소보다 작아지므로 도체폭이 증가하면 Q가 증가하였다. spiral pattern에서는 도체간격을 작게할 때 저항, 인덕턴스, Q는 더 이상 증가하지 않는 도체간격이 존재하지만 meander pattern에서는 인접 도체 사이의 상호 인덕턴스의 부호가 (-)가 됨에 따라 도체 간격은 가능한 한 커야 한다. 턴수가 증가함에 따라 저항, 인덕턴스는 증가하며 spiral pattern에서는 최대의 Q를 가지는 턴수가 존재하지만 meander pattern에서는 인덕턴스의 증가보다 저항의 증가가 크기 때문에 턴수의 증가에 따라 Q는 감소하였다.

• 한국조경학회지
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• 제35권1호
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• pp.69-78
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• 2007

The purpose of this study is to determine the basis for the names of mountain passes that have been different since antiquity, especially names such as those written in Chinese characters. For this purpose, this researcher focused on 108 mountain passes listed in the section of Gyeongsangdo that is a part of Joseon's representative human geographic literature, 'Sinjong Dongguk Yeoji Seungram'. Then the author found out their location by reviewing 'Joseon Hugi Jibang Jido', 'Daedong Yeojido' and 'Hanguk Jimyeong Chongram'. Out of the 180 passes, 30 were finally selected to be analyzed. Again 15 among 30 were found named as 'Hyeon', 7 as 'Ryeong' and remainder were called either term on occasion. The study tried to find out standards according to whether the 30 passes were named as 'Hyeon' or 'Ryeong'. To carry out the study, the author made 3 hypotheses. First, the passes' altitudes were examined. Then visual characteristics were investigated when seen from the summit of the passes. Finally, the number of the passes' turns was investigated to know whether this discriminates between 'Hyeon' and 'Ryeong'. The results of the study can be summarized as follows. With the altitudes and the visual characteristics as mentioned above, it was not possible to determine features that clearly discriminate 'Hyeon' from 'Ryeong'. However, the number of the turns was significantly different in accordance with the names of the passes, 'Hyeon', 'Ryeong' and 'Hyeon or Ryeong'. It seems that 'Hyeon' and 'Ryeong' were discriminatively used depending on how mountain passes were apparently perceived with the number of their turns.

• 한국운동역학회지
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• 제19권4호
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• pp.663-669
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• 2009

본 연구의 목적은 런닝 턴 동작시 많은 정확한 턴을 위한 방법으로 발의 움직임을 역학적으로 분석하기 위함이다. 런닝 턴 동작에 대한 많은 역학적인 요인들 중 정확한 턴을 위해서는 감속이 발생되고 이런 감속은 진행하고자 하는 방향으로 턴을 할 수 있게 해준다. 턴이 시작되는 시점인 발의 회전각과 이로 발생되는 몸통의 각을 3차원 영상분석과 지면반력 분석을 하였다. 따라서, 여러 매개변수들 중 수직축(z축)에서 발의 총 회전각($\theta_f$)/몸통 총 회전각($\theta_d$)= 발의 효과($\varepsilon$)로 단순화 시켜 간단한 방정식을 만들어서 설명했으며, 자료 산출을 위해 평균 속력 4.5m/s에서 진행 방향 $0^{\circ}$, $30^{\circ}$, $60^{\circ}$ 턴에 대한 분석을 통해 턴의 각이 커지면 커질수록 입각기 시간, 발 변위, 좌 우힘이 증가했음을 알 수 있었다.

• 대한조선학회논문집
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• 제54권3호
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• pp.187-195
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• 2017

The operation planning of transports used to move blocks is the one of key factors. Furthermore, reducing the running time through the effective plan contributes to pulling forward the whole logistic process of the shipyard and substantially saving the fuel consumption of itself as well. The past researches of the transporter focused on finding only the shortest distances, so called, Manhattan distance. However, these searching approaches cannot help having the significant difference in the real operational time and distance with the minimum cost approach which considers the speed retardation for turns or safety at the intersection. This study suggests the noble transporter's operational model which could take account of the consuming operational time around the crossroads on the shipyard. Concretely, the proposed method guarantees the minimization of transporters' turns and passage number which are huge burdensome to the operation time and the whole planning of transports with the given period. Resultantly, this paper is willing to explain the appropriateness of our approach, compared with the previous ones.

• 전기학회논문지
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• 제67권3호
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• pp.485-489
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• 2018

Studies have been actively conducted on the magnetic-resonance wireless power transmission (WPT) for commercialization. Such studies are essential for improving the transmission efficiency. In the magnetic-resonance WPT, the inductance (L) and capacitance (C) vary significantly depending on the design of the coils, and the efficiency sharply changes accordingly. To address this problem, studies on the coil design are required. In this study, the S-parameter characteristics according to the number of turns of the coil were analyzed to improve the efficiency of the superconducting WPT. Superconducting coils were designed, and the reflection coefficient ($S_{11}$) according to the turns was analyzed. It was confirmed that the power transmission characteristics were improved as the reactance approached $0{\Omega}$