• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.627-629
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• 2004

V type suspension string sets prevent instabilities from swing motion by the horizontal angle and by wind pressure. These installation conditions are controled mainly 3 items - normal swing angle by horizontal angle of line, unusual swing angle by strong wind, minimum vertical loads. We calculated and analysed that factors for the 765kV transmission line condition. And we were tested swing characteristics of V-string sets in real size test situation. So, we find to installation condition for the V type suspension string sets. This results will be used to design of V type suspension string set and to decision of the installation condition.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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• pp.981-983
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• 1999

In this paper, the electrical characteristics of $\lambda$ vibration-mode piezoelectric transformer for applying to CCFL driving inverter was investigated. Piezoelectric transformer was made of PZT - PMN - 0.5wt% $Nb_{2}O_{5}$ composition. As a results of the electrical characteristics of piezoelectric transformer, when applied voltage was $35[V_{rms}]$ in $100[k{\Omega}]$ load resistance, output voltage was about $710[V_{rms}]$ and output power was more than 2[W]. As output power increased, step-up ratio and temperature was very stable until output power was 2.5[W]. Also, Efficiency was maximum in $70[k{\Omega}]$ load resistance, and about 89[%]. Also, when CCFL was used as load, the maintaining voltage was $700[V_{rms}]$ and the luminescence was $2000[cd/m^2]$ in applying $25[V_{rms}]$ to piezoelectric transformer. Conclusively, piezoelectric transformer fabricated in this paper can be applied to piezoelectric inverter for CCFL driving.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 춘계학술대회 논문집 전기설비전문위원
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• pp.31-34
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• 2005

The 765kV transmission line will be maintained by live-line works for efficient operation, In order to maintain the 765kV transmission lines safely by live-line works, lineman have to know flashover characteristics of the insulator strings with damaged insulators. This paper suggests flashover characteristics of the 765kV insulator strings from experimental test results directly.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.336-339
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• 2001

Transmission line data are very important for studying loadflow. Short circuit data(positive sequence, zero sequence) of 345kV and 154kV line were calulated and compared with KEPCO's line characteristics data. This Paper presents method of verification and complement of line data in PSS/E loadflow data using TMLC (Transmission Line Characteritics) program.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 E
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• pp.2136-2138
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• 1999

In this study, we describe the change of electrical properties of XLPE with electrical-tree degradation. XLPE insulation was used as specimen which was cut off from 22.9kV XLPE insulated cable and made in a type of block. The applying voltages are 8kV, 10kV, 12kV and frequency is 60Hz Ogra needles having tip radius of 10$\mu\textrm{m}$ were inserted in blocks. PD quantity and $tan{\delta}$ and DC current were measured from inception of tree to breakdown and their characteristics were analyzed.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.834-838
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• 2002

In this paper, we have fabricated 4H-SiC schottky diodes utilizing a metal-oxide overlap structure for electric filed termination. The barrier height and Ideality factor were measured by current-voltage, capacitance-voltage characteristics. Schottky barrier height(SBH) were 1.41ev for Ni and 1.35eV for Pt, 1.52eV for Pt/Ti at room temperature and Pt/Ti Schottky diode exhibited Ideality factor was 1.06 to 1.4 in the range of $25^{\circ}C{\sim}200^{\circ}C$. To improve the reverse bias characteristics, an edge termination technique is employed for Pt/Ti/4H-SiC Schottky rectifiers and the device show excellent characteristics with higher blocking voltage up to 780V compared with unterminated devices.

• Nuclear Engineering and Technology
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• 제36권1호
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• pp.47-52
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• 2004

Recently, a new sintered pellet-type LiF:Mg,Cu,Na,Si TL detector which has a high sensitivity and good reusability, named KLT-300(KAERI LiF:Mg,Cu,Na,Si TL detector), was developed by the variation of the dopants concentrations and the parameters of the preparation procedure at KAERI (Korea Atomic Energy Research Institute). In this study, the thermoluminescent characteristics of the newly developed TL detectors were investigated. The sensitivity of the TL detector was compared with that of the TLD-100 by light integration. The dose linearity of the detector was tested from $10^{-6}$ Gy up to 30 Gy. The dose response was very linear up to 10 Gy and a sublinear response was observed at higher doses. The energy response of the detector was studied for photon energies from 20 keV to 662 keV. The result shows that a maximum response of 1.004 at 53 keV and a minimum response of 0.825 at 20 keV were observed. The reproducibility study for the TL detector was also carried out. The coefficients of variation for each detector separately did not exceed 0.016, and for all the 10 detectors collectively was 0.0054. Lower limit of detection for the detector was investigated at 70 nGy by the Harshaw 4500 TLD Reader and the residual signal of the TL detector was found to be $0.57\%$.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.122-122
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• 2010

ZnO is a widely investigated material for the blue and ultraviolet solid-state emitters and detectors. It has been promoted due to a wide-band gap semiconductor which has large exciton binding energy of 60 meV, chemical stability and low radiation damage. However, there are many problems to be solved for the growth of p-type ZnO for practical device applications. Many researchers have made an efforts to achieve p-type conductivity using group-V element of N, P, As, and Sb. In this letter, we have studied the optical characteristics of the antimony-doped ZnO (ZnO:Sb) thin films by means of photoluminescence (PL), PL excitation, temperature-dependent PL, and time-resolved PL techniques. We observed donor-to-acceptor-pair transition at about 3.24 eV with its phonon replicas with a periodic spacing of about 72 meV in the PL spectra of antimony-doped ZnO (ZnO:Sb) thin films at 12 K. We also investigate thermal activation energy and carrier recombination lifetime for the samples. Our result reflects that the antimony doping can generate shallow acceptor states, leading to a good p-type conductivity in ZnO.

• 한국재료학회지
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• 제16권3호
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• pp.178-182
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• 2006

A single electro-discharge-sintering (EDS) pulse (1.0 kJ/0.7 g), from a $300{\mu}F$ capacitor, was applied to atomized spherical Ti-6Al-4V powder in a low vacuum to produce porous-surfaced implant compacts. A solid core surrounded by a porous layer was formed by a discharge in the middle of the compact. XPS (X-ray photoelectron spectroscopy) was used to study the surface characteristics of the implant material. C, O, and Ti were the main constituents, with smaller amounts of Al, V, and N. The implant surface was lightly oxidized and was primarily in the form of $TiO_2$ with a small amount of metallic Ti. A lightly etched EDS implant sample showed the surface form of metallic Ti, indicating that EDS breaks down the oxide film of the as-received Ti-6Al-4V powder during the discharge process. The EDS Ti-6Al-4V implant surface also contained small amounts of aluminum oxide in addition to $TiO_2$. However, V detected in the EDS Ti-6Al-4V implant surface, did not contribute to the formation of the oxide film..

• 한국전자통신학회논문지
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• 제8권6호
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• pp.797-803
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• 2013

본 논문에서는 플라즈마 중합법에 의해 유기절연막을 제작 후 이를 이용한 유기박막트랜지스터의 특성향상을 위해 반도체박막의 표면처리를 하였다. 그 결과 반도체층의 $O_2$ 플라즈마을 활용하여 30 [sec]동안 표면처리시 박막의 표면에너지는 $38mJ/m^2$값에서 $72mJ/m^2$값으로 증가되었으며, 이에 따른 유기트랜지스터의 이동도는 평균값 기준하여 29% 증가된 $0.057cm^2V^{-1}s^{-1}$의 값으로 증가된 값을 얻을 수 있었다. 이로부터 반도체박막 표면개질에 의한 유기트랜지스터의 이동도 특성향상이 가능함을 알았다.