• Proceedings of the KIEE Conference
• /
• 2001.07c
• /
• pp.1585-1587
• /
• 2001

ac PDP 동작에 있어 미량 불순물 가스는 panel 내의 휘도 및 방전 특성에 많은 영향을 미칠것으로 생각된다. $O_2$, O, C 및 $H_2$와 같은 불순물 가스는 ac PDP의 제조 공정 중에 발생하거나, 충전된 방전가스에 혼합되어 발생하는 등 여러 가지 원인으로 나타난다. 이 논문에서는, ac PDP의 동작 가스 중에 미량의 불순물 가스(Ar, $N_2$, $O_2$, $H_2$, $CO_2$)를 주입하여, 이 미량의 불순물 가스로 인한 ac PDP의 휘도 및 방전의 특성변화에 대한 관계를 조사하였다. 그 결과, $O_2$ 가스의 분압이 $2{\times}10^{-3}$/He+Ne+Xe(4%)일 경우, 방전전압은 12% 증가하였고, 휘도는 60% 감소하였다. 또한, $CO_2$ 가스의 경우는 방전전압은 14% 증가하였고, 휘도는 44% 감소하였다.

• Proceedings of the KIEE Conference
• /
• 2001.07c
• /
• pp.1588-1590
• /
• 2001

The voltage controlled ramp waveform(VCR) has recently been used in the reset period prior to addressing for plasma display. However, in this paper, the current controlled ramp waveform(CCR) which may prevent the oscillation of gap voltage cause current growth and decrease the background luminance has been suggested. As a result, in case of CCR method, the contrast ratio was about 14% increased compared with VCR method, whereas the addressing and sustainin discharge characteristics of CCR method were same with those of VCR method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.05b
• /
• pp.142-145
• /
• 2000

The performance of ac plasma display panels (PDP) is influenced strongly by the surface glow discharge characteristics on the MgO thin films. This paper deals with the surface glow discharge characteristics and some physical properties of MgO thin films prepared by reactive RF planar unbalanced magnetron sputtering in connection with ac PDP. The samples prepared with the dc bias voltage of -10V showed lower discharge voltage and lower erosion rate by ion bombardment than those samples prepared by conventional magnetron sputtering or E-beam evaporation. The main factor that improves the discharge characteristics by bias voltage is considered to be due to the morphology changes or crystal structure of the MgO thin film by ion bombardment during deposition process.

• The Journal of the Acoustical Society of Korea
• /
• v.16 no.6
• /
• pp.12-18
• /
• 1997

Beamforming method has a limited spatial resolution because of finite aperture size, so that the estimated source distributions are smoothed within the resolution. Especially for low frequency noise such as mechanical noise, this limitation often diminishes the direct use of beamforming method. In this study, the relation between smoothed beamforming and radiation power distribution of plate has been addressed. By adjustment of aperture size of array, the smoothed beamforming power shows radiation power distribution of plate. Numerical simulations are carried for simply supported plate.

• Journal of IKEEE
• /
• v.15 no.3
• /
• pp.205-210
• /
• 2011

A novel hysteresis tunable monolithic comparator circuit based on a 0.35 ${\mu}m$ CMOS process is suggested in this paper. To tune the threshold voltage of the hysteresis in the comparator circuit, two external digital bits are used with supply voltage of 3.3V. The threshold voltage of the suggested comparator circuit is controlled by 234mV by change of 4 digital control bits in the simulation, which is a close agreement to the analytic calculation.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.46 no.12
• /
• pp.65-71
• /
• 2009

In this paper, we propose an aircraft on-glass antenna for FM radio reception. To obtain broad matching bandwidth, we employed a multiple loop as the basic antenna structure, and the shape of the loops mimics the frame of a window in order to ensure pilots' field of view as large as possible. The detailed design parameters of the multi-loop structure were determined using a Pareto genetic algorithm with a full wave EM simulation tool. The optimized on-glass antenna was built and installed on a Korean utility helicopter (KUH) The measurement results showed a half power matching bandwidth of about 63.3 %, average vertical bore-sight gain of about -12.98 dBi in the FM band.

• 한국전산유체공학회:학술대회논문집
• /
• 2008.03b
• /
• pp.444-447
• /
• 2008

A nuclear fuel test loop (after below, FTL) is installed in IR1 of an irradiation hole in HANARO for testing neutron irradiation characteristics and thermo hydraulic characteristics of a fuel loaded in a light water power reactor (PWR) or a heavy water power reactor (CANDU). There is an in-pile section (IPS) and an out-pile section (OPS) in this test loop. When HANARO is normally operated, the fuel loaded in the IPS has a nuclear reaction heat generated by a neutron irradiation. To remove the generated heat and to maintain an operation condition of the test fuel, a main cooling water system (MCWS) is installed in the OPS of the FTL. The pump can not continuously suck a fluid and not pressurize the fluid during a cold function test. To verify the flow characteristics of the MCWS, a flow net work analysis has been conducted. When the higher elevation pipelines wholly filled with coolant, it was confirmed through the analysis results that the pump pressurized the coolant normally. And the analysis results described the system characteristics with operation temperature and pressure variation satisfactorily.

• 한국정보교육학회:학술대회논문집
• /
• 2006.08a
• /
• pp.161-171
• /
• 2006

본 연구의 목적은 초등학생의 컴퓨터 이용 실태를 분석하여 정보통신 윤리교육에 보다 나은 방향을 제시하기 위해 다음과 같은 연구 문제를 제시하여 연구하였다. 첫째, 초등학생의 컴퓨터 이용 실태는 어떠한가? 둘째, 초등학생의 인터넷 이용과 대화방 사용실태는 어떠한가? 셋째, 초등학생의 불법 복제와 정보통신 윤리 실태는 어떠한가? 위와 같은 연구문제를 해결하기 위해 인천광역시 서구 지역에 있는 초등학교 학생들에게 설문지를 배부하여 응답하도록 하였으며 그 설문자료를 분석한 결과를 요약하면 다음과 같다. 이와 같은 분석 결과를 토대로 결론을 정리하면 다음과 같다. 첫째, 초등학생의 컴퓨터 이용시간 및 컴퓨터를 이용하여 주로 하는 일을 살펴보면 컴퓨터 이용 시간의 적절한 조절 능력과 컴퓨터 활용 능력의 배양이 필요하다. 둘째, 건전한 인터넷 문화를 이룰 수 있도록 지도해야 한다. 셋째, 개인의 인격이 존중되듯이 개인의 사생활도 보호되어야 한다. 넷째, 불건전 사이트에 대한 의식은 대다수의 초등학생들이 부정적인 견해를 견지하고 있다. 따라서 보다 나은 인터넷 서핑을 위해서는 아동들로 하여금 불건전 사이트에 대한 접속을 차단할 수 있는 여러 가지 방법을 모색하고 지도를 통해 불건전 사이트에 접속하지 않도록 하는 교육이 실시되도록 하여야 한다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2019.11a
• /
• pp.71-72
• /
• 2019

In this study, we describe a method of measuring position using the Additional Secondary Factor (ASF) compensation technique of the eLoran concept in the situation where only Loran-C signals are received without eLoran time broadcasting. Next, we describe the result of test performed to verify the method. The test results showed the position accuracy within 20m and we found the possibility of the method. The method is expected to be used to verify user positioning accuracy before improving Loran-C to eLoran.

• Proceedings of the KIEE Conference
• /
• 2002.07c
• /
• pp.1644-1648
• /
• 2002

The relationships between MgO deposition conditions and firing voltage of AC PDP were investigated as a function of ambient temperature. Substrate temperature and growth rate were selected as the major parameters that can affect the properties of MgO most significantly. Firing voltages increase with increasing temperature regardless of deposition conditions of the MgO layer. However, the relative magnitude of the firing voltage variation decrease with increasing substrate temperature and decreasing deposition speed. It was also found that the sample obtained at the condition of lower deposition rate shows better dynamic margin characteristics.