• 한국전기전자재료학회논문지
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• 제28권12호
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• pp.837-842
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• 2015

In this study, the characteristics of electrostatic attenuation in plain shape glass filament sample (0.29 mm thickness, cross section of $12.25cm^2$, $16cm^2$, $20.25cm^2$) for insulator has been measured at temperature of $5^{\circ}C{\sim}38^{\circ}C$, humidity of 50%~90%. The results of this study are as follows. In case of samples that the cross section is $12.25cm^2$, $16cm^2$, $20.25cm^2$ at humidity of 50%~90%, it found that the electrification voltage of electrostatic increased with increasing temperature, with a return to decrease at $20^{\circ}C$. In case of samples that the cross section is $12.25cm^2$, $16cm^2$, $20.25cm^2$ at temperature of $5^{\circ}C{\sim}38^{\circ}C$, it found that the electrification voltage of electrostatic decreased with increasing humidity. In case of the sample at temperature of $20^{\circ}C$ and humidity of 65%, 75%, it found that the electrification voltage of electrostatic increased with increasing cross section. In case of the sample at humidity of 65% and cross section of $12.25cm^2$, the time that it takes to reduce electrification voltage of electrostatic in half decreased to 0.912s, 0.736s, 0.673s with increasing temperature to $10^{\circ}C$ $20^{\circ}C$, $30^{\circ}C$.

• JSTS:Journal of Semiconductor Technology and Science
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• 제1권3호
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• pp.158-166
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• 2001

Based on uniform hot carrier injection (optically assisted electron injection) across the $Si-SiO_2$ interface into the gate insulator of n-channel IGFETs, the threshold voltage shifts associated with electron injection of $1.25{\times}l0^{16}{\;}e/\textrm{cm}^2 between 0.5 and 7 MV/cm were found to decrease from positive to negative values, indicating both a decrease in trap cross section ($E_{ox}{\geq}1.5 MV/cm$) and the generation of FPC $E_{ox}{\geq}5{\;}MV/cm$). It was also found that FNC and large cross section NETs were generated for $E_{ox}{\geq}5{\;}MV/cm$. Continuous, uniform low-field (1MV/cm) electron injection up to $l0^{19}{\;}e/\textrm{cm}^2 is accompanied by a monatomic increase in threshold voltage. It was found that the data could be modeled more effectively by assuming that most of the threshold voltage shift could be ascribed to generated bulk defects which are generated and filled, or more likely, generated in a charged state. The injection method and conditions used in terms of injection fluence, injection density, and temperature, can have a dramatic impact on what is measured, and may have important implications on accelerated lifetime measurements.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1503-1510
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• 2011

The dropper length calculation method about the normal same encumbrance spans is well known independent to whether the pre-sag is given or not. But, the dropper length calculation method for the elevating span which consists in the end area of a tensioning section and normally consists with overlaps is not well known. In this study, firstly, we investigate the dropper length calculation method about the elevating span whether the insulator is contained in or not, we also recognize the effect of dropper length due to the change of the take-off point. Secondly, we very this calculation method with a catenary sample data and check again with Gyeongbu HSL design data.

• 센서학회지
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• 제1권2호
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• pp.131-145
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• 1992

본 논문은 SOI트랜스듀서 및 회로를 위해, Si 직접접합과 M-C국부연마법에 의한 박막SOI구조의 형성 공정을 기술한다. 또한, 이러한 박막SOI의 전기적 및 압저항효과 특성들을 SOI MOSFET와 cantilever빔으로 각각 조사했으며, bulk Si에 상당한다는 것이 확인되었다. 한편, SOI구조를 이용한 두 종류의 압력트랜스듀서를 제작 및 평가했다. SOI구조의 절연층을 압저항의 유전체분리층으로 이용한 압력트랜스듀서의 경우, $-20^{\circ}C$에서 $350^{\circ}C$의 온도범위에 있어서 감도 및 offset전압의 변화는 자각 -0.2% 및 +0.15%이하였다. 한편, 절연층을 etch-stop막으로 이용한 압력트랜스듀서에 있어서의 감도변화를 ${\pm}2.3%$의 표준편차 이내로 제어할 수 있다. 이러한 결과들로부터 개발된 SDB공정으로 제작된 SOI구조는 집적화마이크로트랜스듀서 및 회로개발에 많은 장점을 제공할 것이다.

• 한국가스학회지
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• 제6권4호
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• pp.33-39
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• 2002

[ $9\%$ ]니켈형 LNG 저장탱크는 내조와 외조가 독립적으로 초저온의 LNG를 저장할 수 있는 이중구조로 되어있다. 내조의 재료로는 초저온에서의 기계적 성질이 우수한 $9\%$니켈강을 사용한다. 그리고 내조파손에 의해 유출된 LNG를 저장할 수 있도록 콘크리트 외조가 설계된다. 코너프로텍션은 LNG 유출시 콘크리트 외조 코너부에 발생하는 열응력을 감소시키기 위해 단열재와 $9\%$니켈강 라이너를 시공하는 것을 말한다. 열하중에 의해 팽창과 수축이 반복되는 코너프로텍션의 경우 복잡한 응력상태가 발생되기 때문에 설계상의 어려움이 있다. 현재 한국가스공사에서 운용하고 있는 LNG탱크에는 TKK, KAWASAKI, WHESSOE사에서 설계한 코너프로텍션이 시공되어 있다. 본 논문에서는 유한요소해석을 통해 이들의 설계사양에 대해 ASME Section VIII Div. 2. Appendix 4에 기초한 건전성을 비교/분석하였다.

• Wind and Structures
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• 제23권3호
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• pp.211-229
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• 2016

In recent years, the frequency and duration of supply interruption in electric power transmission system due to flashover increase yearly in China. Flashover is usually associated with inadequate electric clearance and often takes place in extreme weathers, such as downbursts, typhoons and hurricanes. The present study focuses on the wind-induced oscillation of conductor during the process when a downburst is passing by or across a specified transmission line. Based on a revised analytical model recently developed for stationary downburst, transient three-dimensional wind fields of moving downbursts are successfully simulated. In the simulations, the downbursts travel along various motion paths according to the certain initial locations and directions of motion assumed in advance. Then, an eight-span section, extracted from a practical 500 kV ultra-high-voltage transmission line, is chosen. After performing a non-linear transient analysis, the transient displacements of the conductors could be obtained. Also, an extensive study on suspension insulator strings' rotation angles is conducted, and the electric clearances at different strings could be compared directly. The results show that both the variation trends of the transient responses and the corresponding peak values vary seriously with the motion paths of downburst. Accordingly, the location of the specified string, which is in the most disadvantageous situation along the studied line section, is picked out. And a representative motion path is concluded for reference in the calculation of each string's oscillation for the precaution of wind-induced flashover under downburst.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1189-1194
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• 2011

도시형 자기부상열차는 전자기력으로 레일에서 낮은 높이로 부상하여 운행되는 열차이다. 자기부상열차는 궤도와의 직접적인 접촉 없이 움직이기 때문에 소음이 적고 기계적 마찰에 의한 진동이 거의 발생하지 않는다. 또한 급곡선 주행이 가능하고 경사도가 높은 언덕지역도 쉽게 주행 할 수 있기 때문에 도심에서의 새로운 교통수단으로 주목받고 있다. 따라서 도시형 자기부상열차의 성공적인 실용화를 위하여 제3궤조 전차선로 설비와 인터페이스를 통하여 안전성과 신뢰성 확보는 필수 고려 사항중 하나이다. 특히 파워레일, 신축확장장치, 절연 구분장치, 지지금구와 같은 제3궤조 전차선로 설비는 내 부식성, 시공의 편의성 및 유지보수성을 고려하여 설치되어야 한다. 본 논문에서는 자기부상열차 시스템 구축을 위한 제3궤조 설비의 구성요소에 대한 인터페이스 항목을 분석하고 전차선로의 안전성을 높일 수 있는 시스템 엔지니어링 인터페이스 체계를 제시하고자 한다. 또한 제안하는 자기부상용 제3궤조 전차선로 시스템은 한국기계연구원내 시험을 통하여 시스템의 안전성을 증명하였으며, 시스템 구성품의 수명분석을 통해 제3궤조 전차선로 운영의 신뢰성을 향상시키고자 한다.

• 대한기계학회논문집A
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• 제26권10호
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• pp.2187-2193
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• 2002

We present a novel method for 3D microfabrication with LIGA process that utilizes a deep X-ray mask in which a micro-actuator is integrated. The integrated micro-actuator oscillates the X-ray absorber, which is formed on the shuttle mass of the micro-actuator, during X-ray exposures to modify the absorbed dose profile in X-ray resist, typically PMMA. 3D PMMA microstructures according to the modulated dose contour are revealed after GG development. An X-ray mask with integrated comb drive actuator is fabricated using deep reactive ion etching, absorber electroplating, and bulk micromachining with silicon-on-insulator (SOI) wafer. 1mm $\times$ 1 mm, 20 $\mu$m thick silicon shuttle mass as a mask blank is supported by four 1 mm long suspension beams and is driven by the comb electrodes. A 10 $\mu$m thick, 50 $\mu$m line and spaced gold absorber pattern is electroplated on the shuttle mass before the release step. The fundamental frequency and amplitude are around 3.6 kHz and 20 $\mu$m, respectively, for a do bias of 100 V and an ac bias of 20 $V_{p-p}$ (peak-peak). Fabricated PMMA microstructure shows 15.4 $\mu$m deep, S-shaped cross section in the case of 1.6 kJ $cm^{-3}$ surface dose and GG development at 35$^{\circ}C$ for 40 minutes.

• 한국안전학회지
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• 제34권5호
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• pp.55-62
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• 2019

In this paper, we introduce a case of a fire accident during parking of a large truck that is repeatedly occurring. The shape and location of the combustion and electrical singularity commonly found in other vehicle fire accidents could limit the starter motor as the ignition section. In addition, it was possible to confirm the electrical melting singularity that could act as a cause of ignition between the start motor B terminal and the start motor enclosure. By combining the above investigations and investigations, it was possible to estimate the electric fire expressed from insulation breaking of the starter motor B terminal, and by using the renewable starter motor comparison product mounted on the fire vehicle, an experiment was performed to reproduce the ignition process from the starter motor under specific conditions. So. It is hoped that this will raise awareness about vehicle fires, which can lead to large fires or casualties, share the risks of using starter motors for regeneration, and help in the rapid and accurate investigation of similar vehicle fires in the future.