• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1818-1820
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• 2000

Due to recent technology advances, needs for flat panel displays, plasma display panels(PDPs) whose advantages are simple structure, high resolution, wide viewing angle is increasingly expected to be the first flat panel of large screen, walt hanging TVs. But the luminance and luminous efficiency of color PDP is net up to the level of a CRT. So, New electrode shape which is different from the conventional electrode has to propose to improve the luminance and luminous efficiency. In this paper, we suggested new shaped electrodes. In new shaped electrode, the discharge current was reduced compared with conventional type by reducing the unnecessary diffusion loss near the barrier rib. However, the luminance was nearly the same as conventional type. So, the luminous efficiency improved about 35%.

• Journal of Information Display
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• v.2 no.4
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• pp.63-67
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• 2001

The switching power loss due to the panel capacitance during sustain period in AC PDP driving system can be minimized by using the energy recovery circuits. We proposed a new energy recovery circuit, SER1 (Seoul national univ. Energy Recovery circuit 1st). The experimental results of its application to a 42-inch surface discharge type AC PDP showed superior performance of SER1 in energy recovery efficiency and low distortion voltage waveform. Energy recovery efficiency of SER1 was measured up to 92.3 %, and the power dissipation during the sustain period was reduced by 15.2 W in 2000 pulse/frame compared with serial LC resonance energy recovery circuit.

• Journal of Information Display
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• v.2 no.1
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• pp.14-19
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• 2001

Plasma display panel(PDP) have gained great attention due to their potential application to large-area display including HDTV. The luminance and luminous efficiency of PDP, however, should be improved to realize this goal. In this study, we examined experimentally the effects of phosphor thickness and discharge gap on the luminance and luminous efficiency of ac PDP. For the rib height of 110 ${\mu}m$, whereas the optimum phosphor thickness was about 30 ${\mu}m$. The optimum thickness of green phosphor was about 50 ${\mu}m$ for the rib height of $120{\sim}160\;{\mu}m$.

• Journal of KIEE
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• v.11 no.1
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• pp.46-50
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• 2001

In order to improve the luminous efficiency in ac PDP(Plasma Display Panel), we have suggested the new structures of sustain electrodes with waffle-type barrier ribs and the discharge current for a given pulse voltage has been decreased by eliminating the electrode area which has nothing to do with visible light emission area compared with conventional structure. As a result, the luminous efficiency was improved about 30% compared with the conventional structure.

• Journal of Technologic Dentistry
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• v.34 no.3
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• pp.221-226
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• 2012

Purpose: This study was performed to compare mechanical properties for sintering methods of porous Ti implants. Methods: The specimens of Ti implant were fabricated by several sintering methods. One of them is spark plasma sintering(SPS). Another is electro discharge singering(EDS) and the other is high vacuum sintering(HVS). Mechanical properties of porous Ti implants were evaluated by universal testing machine(UTM) and their fracture surface was examined under a sanning electron microscope(SEM). Results: The tensile strength was in a range of 71 to 230 MPa, and Young's modulus was in a range of 11 to 21 Gpa. It matched with range of cortical bone. Conclusion: Mechanical properties of porous Ti implants were similar to human bone. It was shown that sintering methods of spherical powders can efficiently produce porous Ti implants with various porosities. Porous metals will be commonly used in orthopedic and dental application despite of initial focus has been on bioceramics.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.35-38
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• 2005

Full-HDTV급 PDP를 구현하기 위해서는 고속 어드레스 구동이 필요하며 이러한 기술은 AWD 구동방식으로 구현하는 것이 용이하다. AWD 구동방식은 하나의 sustain 펄스 휴지기안에 복수개의 scan 펄스를 설치하는 것이 바람직하며 이 경우 sustain 펄스와 sustain 펄스 사이가 넓어진다. 본 연구에서는 이 휴지기를 고려한 sustain 방전특성을 해석하였다. 실험결과 address 바로 다음에 나오는 첫 번째 sustain 펄스는 공간전하 의존도가 높으며 두 번째 펄스부터는 공간전하 의존도보다는 벽전하 의존도가 더 높다는 사실을 알았다. 또한 수십${\mu}s$를 가지는 휴지기간에도 균일한 sustain 동작마진을 얻을 수 있음을 알았다.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.8
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• pp.415-419
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• 2004

A pulse power supply using IGBTs and MPC (magnetic pulse compression) circuit was developed for a metal vapor laser. The life time of the pulse power supply is expected to be much longer than that of a vacuum tube or thyratron type pulse power supply. A series-connected IGBT array generated a long pulse of its pulse width 2 ${\mu}\textrm{s}$ md then it was compressed to less than 100 ns by a three stage MPC circuit. This pulse power supply was applied to a laser plasma tube of 10 mm inner diameter and 0.5 m discharge length. and successfully operated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.233-236
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• 1997

An investigation has been made of the various plasma chemistry reactions that occur in the corona discharge of an electrostatic precipitator operating in a typical flue gas. As the results of investigation, sulphur dioxide is removed principally by reactions with OH radicals to produce sulphuric acid, while nitrogen oxides are removed principally by reduction via the N radical to molecular nitrogen. If electrostatic precipitator\ulcorner used for flue gases are operated with positive voltages instead of negative dc voltages, there are significant reductions in the emission of the undesirable gases SO$_2$, NO, and NO$_2$. Thus, in this paper we design the bidirectional pulse generator for removal of flue gas, where the pulse width is more than 50[nsec] and the maximum output voltage is more than 100[kVl.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.510-514
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• 1997

The thin film that is electrically conductive and optically transparent is called conductive transparent thin film. ITO(Indium-Tin Oxide) which is a kind of conductive transparent thin film has been widely used in solar cell, transparent electrical heater, selective optical filter, FDP(Flat Display Panel) such as LCD(Liquid Crystal Display), PDP(Plasma Display Panel) and so on. Especially in PDP, ITO films is used as a transparent electrode in order to maintain discharge and decrease consumption power through the improvement of cell structure. In this study, we prepared ITO by reactive r.f. sputtering with indium-tin(Sn 10wt%) alloy target instead of indium-tin oxide target. The ITO films deposited at low temperature 15$0^{\circ}C$ and 8% $O_2$. Partial pressure showed about 3.6 Ω/$\square$. At the end of firing, the resistance of ITO was decreased, the optical transparence was improved above 90%.

• Proceedings of the KIEE Conference
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• 2002.06a
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• pp.64-66
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• 2002

This study is to develop electromagnetic plasma reactors for indoor air purification, Removal effect of nitrogen oxide using magnetic field are investigated. And AC or DC high voltage is applied for corona discharge, flow rates are 150${\sim}$1500${\ell}$/min and NO initial concentration is about 10 ppm. In the results, NOx removal rate by AC power is about 10 % higher than that by DC power under the experimental condition of 700 ${\ell}$/min, 5 magnets. When magnet is applied to the reactor, NOx removal rate increased.