• IEIE Transactions on Smart Processing and Computing
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• 제5권6호
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• pp.440-444
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• 2016

In this paper, an equivalent circuit model for near-field noise emission is proposed to implement a multimedia operation-monitoring system for mobile devices. The proposed model includes a magnetic field probe that captures noise emissions from multimedia components, and a transfer function for near-field noise coupling from a transmission line source to a magnetic field probe. The proposed model was empirically verified with transfer function measurements of near-field noise emissions from 10 kHz to 500 MHz. With the proposed model, a magnetic field probe was optimally designed for noise measurement on a camera module and an audio codec in a mobile device. It was demonstrated that the probe successfully captured the near-field noise emissions, depending on the operating conditions of the multimedia components, with enhanced sensitivity from a conventional reference probe.

• Journal of the Korean Physical Society
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• 제73권11호
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• pp.1698-1702
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• 2018

We simulate the light transmission through an extremely small nanoscale aperture having a 10 nm diameter punctured in a metal film positioned at the center of a plasmonic bull's eye grating. A considerable directive emission of transmitted light with a divergence angle of 5.7 degrees was observed at $10{\mu}m$ from the nanohole opening at the frequency of surface plasmon polariton excitation, an confirmed by measuring the distance dependent transmission amplitude. Observations of the electric field in cross-sectional, near-field, and far-field views near-field enhancement associated with the surface plasmon excitation, and the interference of the electric field light through the nanohole in the near-field region is responsible for such a considerable directive emission.

• 한국세라믹학회지
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• 제39권1호
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• pp.92-98
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• 2002

Pb(Zr$_{0.8}$Ti$_{0.2}$)O$_3$강유전체 음극의 상부 전극 크기를 변화시키며(500$mu extrm{m}$~900$\mu\textrm{m}$)비대칭 전극 구조에서의 전자 방출에 대하여 연구하였다. 펄스 전기장을 가했을 때 나타나는 분극 반전에 의한 전류 밀도는 상부 전극 크기를 감소시킴에 따라 증가하였다. 이것은 비대팅 전극 구조에 의해 강유전체 표면에서 stray-field가 발생하고, stray field가 전극의 모서리 부근의 강유전체 표면 하부에도 분극 반전을 발생시켰기 때문이다. 전기장 전산모사를 통하여 이러한 stay-field의 존재 가능성을 예측할 수 있었고, 분극 반전에 의한 전류 밀도 측정 결과 stray-field가 미치는 거리는 약 11-l4$\mu\textrm{m}$이었다. 전자방출의 문턱전계는 항전계 의 약 3배인 61-68kV/cm이었으며, 문턱전계가 단순히 강유전체의 항전계에 의해 결정되는 것이 아니라, 강유전 음극의 구조에 의해 결정되는 stray-field의 세기와 stray-field가 미치는 거리에 영향을 받음을 전산모사를 통해 예측할 수 있었다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권1호
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• pp.59-63
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• 2000

For the Mo-tip field emitter array, the method by which the geometrical structure of the gate insulator wall could be modified in order to improve field emission properties(turn-on voltage and gate leakage current). The device having a gate insulator of complex shape, which means the combined geometrical structure with round shape made by wet etching and vertical shape made by dry etching processes, was fabricated and the field emission properties of the three kinds of devices were compared. As a result, the electric field applied to tip apex could be increased and gate leakage current could be decreased by employing the gate insulator having geometrical wall structure of mixed shape. Finally, the obtained empirical results were analyzed by simulation of electric field distribution at/near the tip apex and gate insulator using SNU-FEAT simulator.

• 한국재료학회지
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• 제9권10호
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• pp.1032-1036
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• 1999

Pb($\textrm{Zr}_{0.5}\textrm{Ti}_{0.5}$)$\textrm{O}_3$ 강유전체의 상부 전극 크기를 변화시키며 펄스 전기장에 의한 전자 방출 특성 및 열화에 대하여 연구하였다. 상부 전극 크기 감소에 따라 상부 전극 모서리 부근에서 분극 반전에 기여하는 강유전체 분율이 증가되어 분극이 높아졌으며, ANSYS 5.3에 의한 전기장 시뮬레이션을 통하여 비대칭 전극 구조에서의 상부 전극 모서리 부근의 전기장이 증가한다는 것을 알 수 있었다. 분극 증가에 기여하는 상부 전극 모서리 주변의 강유전체의 부피 및 전극크기당 전자 방출량은 상부 전극 크기에 무관하였다. 전자 방출 횟수에 따라 상부 전극이 침식되어 분극 및 유전 상수는 감소하였으나 전극 복구에 의해 재생되었으며, 강유전체의 표면 손상에 의해 항전계 및 유전 손실은 증가되었다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.568-570
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• 2004

A shielding effectiveness of mesh screen filter of plasma display panel (PDP) has been calculated in this paper. Since the screen filter is located near the radiation source, the near field wave impedance of the radiation source, i.e., the PDP electrodes, has been considered to calculate the shielding effectiveness. The near field shielding effectiveness of screen filter at 30${\sim}$300 MHz has been estimated to be more than 65${\sim}$80 dB. The measured shielding effectiveness of screen filter is 10${\sim}$50 dB at 30${\sim}$300 MHz[1]. The resulting discrepancy indicates that there are other EMI emission sources such as emission from PCB and cable besides the PDP electrodes.

• 한국광학회:학술대회논문집
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• 한국광학회 2001년도 하계학술발표회
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• pp.10-11
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• 2001

• Journal of the Optical Society of Korea
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• 제6권1호
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• pp.1-4
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• 2002

We studied experimentally the angular spectrum of the light emitted from dye Molecules near a plane boundary. It is confirmed that the molecules near the boundary can emit light into the evanescent wave mode, and the light emission with the angle greater than the critical angle is detected with good accuracy. The angular spectrum of the spontaneous radiation is measured, and the spectrum shows contributions from the molecules both near and far away from the boundary. The polarization dependence and the pumping angle dependence are also measured. The experimental results are in good agreement with quantum theory.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.859-862
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• 2003

Well-aligned multiwall carbon nanotubes (MWCNTs) were prepared at low temperature of 400 $^{\circ}C$ by utilizing a radio frequency plasma-enhanced chemical vapor deposition (rf-PECVD) system. The MWCNTs were treated by an external rf plasma source and an ultra-violet laser in order to modify structural defect of carbon nanotube and to ablate possible contamination on carbon nanotube surface. Structural properties of carbon nanotubes were investigated by using a scanning electron microscopy (SEM), Raman spectroscopy, Fourier transformer Infrared spectroscopy (FTIR) and transmission electron microscope (TEM). In addition, the emission properties of the MWNTs were measured for the application of field emission display (FED) in near future. Various post treatments were found to improve the field emission property of carbon nanotubes.

• 한국연소학회지
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• 제17권4호
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• pp.60-65
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• 2012

The MILD combustion and pollutant emission characteristics were investigated computationally. The temperature of supplying air-stream and mixing rate (${\Omega}$) of exhaust gas in the air-stream were adjusted to investigate the effects of those parameters on the MILD combustion in jet flow field. The emission indices for NO (EINO) and CO (EICO) were introduced to quantify the amount of those species emitted from the combustion. The high-temperature region disappeared gradually as the mixing rate increased for fixed air-stream temperature. The EINO increased as the air-stream temperature became higher for fixed mixing rate, and the EINO decreased dramatically with increasing the mixing rate for each air-stream temperature condition. The EICO also decreased with increasing the mixing rate and it was nearly independent of air-stream temperature except for near ${\Omega}$ = 0.7. It was found that the CO supplied in the air-stream can be destroyed in the MILD combustion over the certain mixing rate.