• 대한전자공학회논문지
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• 제5권3호
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• pp.25-30
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• 1968

세논 섬광관의 방전회로에 관한 특성을 상세히 논했다. 섬광관은 전류에 비전형적이므로 방전회로에 관한 의 비선형 미분방정식을 유도하여 해를 상이형전자 계산기로 구했다. 또한 더욱이 임의의 섬광관에 대한 입력에너지 펄스지속시간 및 모양, 인덕턴스, 콘덴서 그리고 동작전압에 대해 완전히 고찰했다. 아울러 본 해석결과를 이용하면 성광관 방전계통회로를 정확히 설계할 수 있음을 제시했다.

• 대한전기학회논문지
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• 제40권6호
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• pp.626-629
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• 1991

The negative wire of an electrolytic ozone generator, proposed by authors, has been contaminated by attaching the impurity particulate in tap water, which is called BUILD-UP phenomenon. The higher applied voltage and the larger wire diameter have shown the higher build-up rate, which makes the current reducing largely and concurrently the ozone production smaller. It is found that the positive electrode of the ozone generator has a strong SELF-CLEANING effect by detaching the impurity particulate from its surface, which, however, is used us a novel means of solving the build-up problem. As a result, the build-up problem can be solved effectively by applying an alternate square wave pulse voltage to the electrodes so as to get the self-cleaning ability on the both electrodes during each of the half pulse duration time.

• 한국초전도ㆍ저온공학회논문지
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• 제6권3호
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• pp.1-5
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• 2004

This paper presents a study on the stability of bare and cu-laminated YBCO-coated conductor. we investigate the characteristics of quench/recovery behavior of YBCO test samples. bare and copper-laminated, by subjecting each test sample. immersed in a bath of liquid nitrogen boiling at 77.3 K. to a transport current pulse superimposed to a baseline DC current of 90-95% the critical current. The current pulse has an amplitude up to ∼4.5 times the critical current and a duration of 300 ms. This paper presents both experimental and simulation results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전기물성,응용부문
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• pp.120-122
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• 2003

We have been investigated phase-change with temperature and electric field in chalcogenide $Ge_2Sb_2Te_5$ thin film. $T_c$(crystallization temperature) is confirmed by measuring the resistance and conductivity with the varying temperature on the hotplate. We have measured I-V characteristics with $Ge_2Sb_2Te_5$ chalcogenide thin film. It is compared with I-V characteristics after impress the variable pulse. The pulse has variable height and duration that used voltage and current source.

• Journal of Power Electronics
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• 제14권6호
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• pp.1314-1321
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• 2014

A new simplified topology for a dynamic voltage restorer (DVR) based on direct converter with a reduced number of switches is presented. The direct converter is fabricated using only three bi-directional controlled switches. The direct converter is connected between the grid and center-tapped series transformer. The center-tapped series transformer is used to inject the compensating voltage synthesized by the direct converter. The DVR can properly compensate for long-duration, balanced, and unbalanced voltage sag and swell by taking power from the grid. The switches are driven by ordinary pulse width modulation signals. Simulation and hardware results validate the idea that the proposed topology can mitigate sag of 50% and swell of unlimited quantity.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1199-1202
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• 2003

In this research, microfabrication technique using localized electrochemical deposition is presented. Electric field is localized near the tip end region by applying ultra short pulses. Platinum tip is used as the counter electrode and copper is deposited on the copper substrate in 0.5 M CuSO$_4$ and 0.5 M H$_2$SO$_4$ electrolyte. The deposition characteristics such as size, shape, and structural density according to pulse duration and applied voltage are investigated. Micro-columns less than 10 $\mu\textrm{m}$ in diameter are fabricated using the presented technique. The process can be potentially used for three dimensional metal structure fabrications with micrometer feature size.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.227-227
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• 1999

Plasma display panel(PDP) is a leading technology for large-area flat panel displays. A current issue in operating the PDP cell is that the efficiency of the PDP cell is very low. To increase the efficiency of the PDP cell, the visible light needs to be maximized and the power consumption minimized. Since the excited xenons are related to the production of the visible light, it is important to optimize the cell geometry and the gas composition that produce the excited xenons more efficiently. A 2D-fluid code (FL2P) is developed and used to simulate the plasma dynamics and the radiation transport in the PDP cell. The cell is optimized with the code for various operating conditions and cell dimensions such as the voltage pulse, electrode length, electrode spacing, gap size, dielectric constant, gas mixture ratio, pressure, and pulse duration.

• International Journal of Precision Engineering and Manufacturing
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• 제6권2호
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• pp.5-11
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• 2005

Among the micro machining techniques, micro EDM is generally used for machining micro holes, pockets, and micro structures on difficult-cut-materials. Micro EDM parameters such as applied voltage, capacitance, peak current, pulse width, duration time are very important to fabricate the tool electrode and produce the micro structures. Developed micro EDM machine is composed of a 3-axis driving system and RC circuit equipped with pulse generator. In this paper, using micro EDM machine, the characteristics of micro EDM process are investigated and it is applied to micro holes, slots, and pockets machining. Through experiments, relations between machined surface and voltages and between MRR and feedrate are investigated. Also the trends of tool wear are investigated in case of hole and slot machining.

• 한국자기학회지
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• 제7권4호
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• pp.212-216
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• 1997

충전에너지 18 kJ의 커패시터뱅크 및 펄스코일에서 생성되는 주기 10.12 ms의 정현감쇄진동형 펄스자장을 이용하여 최대 인가자장 130 kOe의 펄스마그네토미터를 구성하였다. 자성측정은 펄스자장의 첫 번째와 두 번째 정방향 자장파크 사이의 파형을 이용하여 유도법으로 측정하였다. NdFeB 소결자석의 측정에 있어서 와전류에 의한 측정오차, 즉, 직류특성과의 차이가 직경 5 mm 이하의 시편을 사용할 경우 3% 이내인 펄스자장형 자기이력곡선 측정장치를 제작하였다.

• Journal of the Optical Society of Korea
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• 제13권1호
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• pp.86-91
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• 2009

The electrons injected into a laser wakefield undergo betatron oscillation and give rise to the emission of intense X-ray radiation. To investigate the generation conditions of the X-rays, the relativistic motion of an electron injected in an off-axis position has been simulated with wakefield profiles which are pre-calculated with a two-dimensional particle-in-cell code. The wakefield with a plasma density of $1.78{\times}10^{18}\;cm^{-3}$ is generated by the laser with an intensity of $1.37{\times}10^{18}\;W/cm^2$ and a pulse width of 30 fs. From the calculation of the single particle motion, the characteristics of the betatron radiation are investigated in the time domain. As the transverse injection position increases, the power and the duration time of the radiation increase, but the width of each pulse decreases.