• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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• pp.148-150
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• 2008

In this paper, we report the improved driving methode using planar-gate for field emission light source. Due to the cold cathode in field emission device, it has advantage for driving system in terms of high speed pulse driving with narrow duty ratio. This paper shows that our driving method offers the stable and reliable driving system without rapid electric field variation for field emission light source.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.200-200
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• 2012

We investigated a flexible transparent film using the spinning multi-walled carbon nanotubes (MWCNTs). Spin-capable MWCNTs on iron catalyzed on a SiO2 wafer was grown by chemical vapor deposition, which was performed at $780^{\circ}C$ using C2H2 and H2 gas. The average diameter and length of MWCNTs grown on the substrate were ~15 nm and $250{\sim}300{\mu}m$, respectively. The MWCNT sheets were produced by continuously pulling out from well-aligned MWCNTs on a substrate. The MWCNT sheet films were produced simply by direct coating on the flexible film or grass. The thickness of sheet film was remarkably decreased by alcohol spraying on the surface of sheet. The alcohol splay increased transmittance and decreased electrical resistance of MWCNT sheet films. Single and double sheets were produced with sheet resistance of ~699 and ${\sim}349{\Omega}/sq$, respectively, transmittance of 81~85 % and 67~72%, respectively. The MWCNT sheet films were heated through the application of direct current power. The flexible transparent heaters showed a rapid thermal response and uniform distribution of temperature. In addition, MWCNT yarns were prepared by spinning a bundle of MWCNTs from vertically super-aligned MWCNTs on a substrate, and field emission from the tip and side of the yarns was induced in a scanning electron microscope. We found that the field emission behavior from the tip of the yarn was better than the field emission from the side. The field emission turn-on voltages from the tip and side of MWCNT yarns were 1.6 and $1.7V/{\mu}m$, respectively, after the yarn was subjected to an aging process. Both the configuration of the tip end and the body of the yarn were changed remarkably during the field emission. We also performed the field emission of the sheet films. The sheet films showed the turn on voltage of ${\sim}1.45V/{\mu}m$ during the field emission.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.433-433
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• 2016

Carbon nanotubes (CNT) emitter has widely become an attractive mechanism that draws growing interests for cold cathode field emission. CNT yarns have demonstrated its potential as excellent field emitters. It was demonstrated that a small focal spot size was achieved by manipulating some electrical parameters, such as applied bias voltage at the mesh gate, and electrostatic focal lenses, geometrical parameters, such as axial distances of the anode, and the electrostatic focal lens from the cathode assembly, and the dimension of the opening of the electrostatic lens. Electrical-optics software was used to systematically investigate the behavior of the electron beam trajectory when the aforementioned variables were manipulated. The results of the experiment agree with the theoretical simulation results. Each variable has an individual effect on the electron beam focal spot size impinging on the target anode. An optimum condition of the parameters was obtained producing good quality of X-ray images. Also, MWCNT yarn was investigated for field emission characteristics and its contribution in the X-ray generation. The dry spinning method was used to fabricate MWCNT yarn from super MWCNTs, which was fabricated by MW-PECVD. The MWCNT yarn has a significant field emission capability in both diode and the triode X-ray generation structure compared to a MWCNT. The low-voltage-field emission of the MWCNT yarn can be attributed to the field enhancing effect of the yarn due to its shape and the contribution of the high-aspect-ratio nanotubes that protrude from the sides of the yarn. Observations of the use of filters on the development of X-ray images were also demonstrated. The amount of exposure time of the samples to the X-ray was also manipulated. The MWCNT yarn can be a good candidate for use in the low voltage field emission application of X-ray imaging.

• 한국산학기술학회논문지
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• 제16권1호
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• pp.837-844
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• 2015

본 연구는 대도시의 공원 및 녹지를 탄소배출 저감형으로 변화시키기 위한 도시 그린필드의 조성 및 관리방안을 제시함으로서, 저탄소 사회실현 및 녹색성장을 위해 국내 도시가 나아가야 할 공원녹지의 계획방향을 제안하는데 목적을 두고 있다. 연구의 순서로는 먼저 이론고찰을 통해 탄소저감형 도시계획 및 도시 그린필드의 개념과 특성을 검토함으로써 탄소저감과 도시 내 그린필드의 관련성을 고찰한다. 이어서 국내 도시 그린필드의 문제와 과제에 대하여 파악하고, 탄소저감형 그린시티계획을 수립한 대전광역시를 대상으로 공원녹지 상황을 도시계획을 통해 파악함으로서 도시 그린필드의 여건을 분석한다. 끝으로 대전광역시 그린필드의 조성 및 관리방안을 광역 그린네트워크, 그린필드 보존 및 확충 그리고 법 및 제도적 측면에서 연구함으로서 그린필드의 확보에 중점을 두고 공원 및 녹지계획을 수립하고 있는 국내 대도시의 미래 탄소저감형 그린필드의 계획방향을 제시한다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1996년도 재료학회 추계학술발표회
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• pp.87-87
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• 1996

• 전자공학회논문지 IE
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• 제44권3호
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• pp.1-5
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• 2007

Si 팁 기술의 장점을 살리면서 팁을 실리사이드화하여 팁표면의 열화학적 내구성을 증가시키고 전계방출 전류밀도를 금속 팁에 가깝게 끌어올릴 수 있는 새로운 3극관 형태의 전계방출 팁 구조를 제작하였다. 제작된 소자의 전계방출 특성을 $10^{-8}Torr$의 초고진공 상태에서 캐소드-애노드 간격을 $100{\mu}m$로 하여 측정한 결과, turn-on 전압이 약 40V로, 방출전류가 인가 전압 150V에서 약 $69{\mu}A$로 나타났다.

• 한국전기전자재료학회논문지
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• 제13권5호
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• pp.426-430
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• 2000

We have studied the field emission characteristics of multi-layered diamond-like-carbon (DLC) films deposited by vertical electrodes type plasma enhanced chemical vapor deposition with CH$_4$ and H$_2$ mixture. We deposited a thin layer of DLC on the p$^{+}$-Si substrate and then turned off plasma before another deposition of a new DLC layer. The thickness and the number of DLC layers are varied. The emission characteristics of multi-layered DLC films were compared with conventional one. The multi-layered DLC film shows higher emission current than conventional one.e.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.341-344
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• 2005

The method of measurement for field tests on noise emission from water supply installations in bathroom of apartment house. This part of standard gives detailed descriptions for Held tests on noise emission from water supply installations in bathroom, bed room and living room of apartment house. Noise emission affect from working pressure and quantity of flow. The measuring position have to investigated measuring for emission noise.

• Journal of Information Display
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• 제2권3호
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• pp.44-47
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• 2001

The extracted field emission current can be used to controllably heat microfabricated cold field emission cathode tips. The heating can be sufficient to smooth and recrystallize the tip surface by surface self-diffusion, and at least partially clean the surface of contaminants by thermal desorption. Self-heating not only allows for the achievement and maintenance of stable emission characteristics, but can be used to make the current-voltage characteristics of microfabricated field emitter tips nearly identical to one another. The resulting improvement in emission uniformity will allow for more reliable array operation at increased electron emission current densities.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.66.2-66.2
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• 2011

A polymer-based multi-walled carbon nanotube (MWCNT) field emission device was fabricated from a composite dispersion of MWCNTs and waterborne polymethyl methacrylate (PMMA). The waterborne PMMA synthesized through the emulsion polymerization method was added to minimize the reagglomeration of dispersed MWCNTs with surfactants in water, and increase the adhesion between the and the substrate. The field emission properties of the fabricated device were optimized by adjusting the density of the emitter and the adhesion between the MWCNTs and the substrate. These were done by controlling the polymer concentration added to the MWCNT dispersion, as well as the amount of spray coating on the substrate. The results confirm the successful fabrication of a polymer-based MWCNT field emission device with a low field of 1.07 $V/{\mu}m$ and a good electric field enhancement factor of 2445. The device was fabricated by adding 0.8 mg/mL of polymer solution to the MWCNT dispersion and applying 20 cycles of spray coating. Application of this same MWCNT/polymer composite solution to a flexible polymer substrate also resulted in the successful fabrication of an electric field emission device with uniform emission and long time stability.