• 전기학회논문지
• /
• 제63권2호
• /
• pp.250-256
• /
• 2014

In this study, we deposited and investigated ${\mu}c$-Si:H thin films prepared by Plasma Enhanced Chemical Vapor Deposition(PECVD) system. To deposition silicon thin films, we controlled $SiH_4$ gas concentration, RF input power, and heater temperature. According to the experiments, the more $SiH_4$ gas concentration increased, deposition rate also increased but crystalline property decreased at the same conditions. In the RF input power case, deposition rate and crystalline property increased together when the input power increased from 100[W] to 300[W]. If RF input power was 300[W], deposition rate has reached saturation point. In the heater temperature, deposition rate increased when heater temperature increased. Crystalline property maintained a certain level until heater temperature was $250[^{\circ}C]$. And then it was a suddenly increased. Multistep method has been proposed to improve the quality of ${\mu}c$-Si:H thin film. $SiH_4$ gas was injected with a time interval. According to the experiments, crystallite ratio improve about 20~60[%] and photo conductivity increased up to six times.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 1998년도 전력전자학술대회 논문집
• /
• pp.58-62
• /
• 1998

In the industrial motor drive systems, a torsional vibration is often generated because of the elastic elements in torque transmission. One of general methods for the system is H$\infty$ controller to suppress the torsional vibration and reject the torque disturbance. vibration and reject the torque disturbance. Moreover, the two-degrees-of-freedom controller, which includes the H$\infty$ controller, is designed in order to improve the command following property. In this paper, we propose a new H$\infty$ controller with partial state feedback. This method having simple structure satisfies with the fast command following property and the attenuation of disturbances and vibrations simultaneously, just like the complicated TDOF H$\infty$ controller

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2000년도 하계학술대회 논문집 A
• /
• pp.576-578
• /
• 2000

This paper address the prediction method of a soil thermal property depending on soil moisture contents and suggests the guideline to determine the soil thermal resistivity for the calculation of the cuurent carrying capacity of underground power cables in Korea.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.529-534
• /
• 2005

In this paper, a new type of output feedback control, called a $H_2/H_{\infty}$ fnite memory control (FMC), is proposed for deterministic state space systems. Constraints such as linearity, unbiasedness property, and finite memory structure with respect to an input and an output are required in advance to design $H_2/H_{\infty}$ FMC in addition to the performance criteria in both $H_2$ and $H_{\infty}$ sense. It is shown that $H_2$, $H_{\infty}$, and mixed $H_2/H_{\infty}$ FMC design problems can be converted into convex programming problems written in terms of linear matrix inequalities (LMIs) with some linear equality constraints. Through simulation study, it is illustrated that the proposed $H_2/H_{\infty}$ FMC is more robust against uncertainties and faster in convergence than the existing $H_2/H_{\infty}$ output feedback control schemes.

• 대한수학회보
• /
• 제45권1호
• /
• pp.59-66
• /
• 2008

Keskin and Harmanci defined the family B(M,X) = ${A{\leq}M|{\exists}Y{\leq}X,{\exists}f{\in}Hom_R(M,X/Y),\;Ker\;f/A{\ll}M/A}$. And Orhan and Keskin generalized projective modules via the class B(M, X). In this note we introduce X-local summands and X-hollow modules via the class B(M, X). Let R be a right perfect ring and let M be an X-lifting module. We prove that if every co-closed submodule of any projective module P contains Rad(P), then M has an indecomposable decomposition. This result is a generalization of Kuratomi and Chang's result [9, Theorem 3.4]. Let X be an R-module. We also prove that for an X-hollow module H such that every non-zero direct summand K of H with $K{\in}B$(H, X), if $H{\oplus}H$ has the internal exchange property, then H has a local endomorphism ring.

• 한국전기전자재료학회논문지
• /
• 제21권1호
• /
• pp.5-11
• /
• 2008

To study the effects of $H_2$ gas on AIN insulation thin film, we prepared AIN thin film on Si and GaAs substrate by means of reactive sputtering method using $H_2$ gas as an additives, With treatment conditions of $H_2$ gas AIN thin film shows variable electrical properties such as its crystallization and hysterisis affected to electrical property, As a results, AIN thin film fabricated on Si substrate post-treated with $H_2$ gas for 20 minutes shows much better an insulation property than that of pre-treated, And AIN film treated with $H_2$ gas comparing to non-treated AIN film shows a flat band voltage decreasment. But In GaAs substrate $H_2$ gas does not effect on the flat band voltage.

• 한국식품과학회지
• /
• 제22권3호
• /
• pp.350-356
• /
• 1990

참깨와 들깨 단백질을 알칼리에서 추출시킨 후 참깨는 pH6.0, 들깨는 pH4.0에서 침전시켜 분리 단백질을 제조하여 그들의 기능성 즉, 용해도, 유화성, 기포성, 유지 및 수분 흡착력 등을 pH와 염농도를 달리하여 측정하였다. 단백질 용해도는 참깨 단백질이 pH6.0에서, 들깨와 대두 단백질은 pH4.0에서 가장 낮아 등전점을 보이었고, pH2.0과 pH8.0 이상에서는 크게 증가하였다. 0.1M NaCl 첨가시에는 참깨 단백질과 들깨 단백질의 경우 전 pH 범위에서 단백질 용해도가 증가하였다. 유화력은 각 시료 단백질의 등전점 부근에서 가장 낮았으며 0.1M NaCl 첨가시에는 모든 시료들의 유화력이 증가되었으나 0.5M NaCl 농도에서는 오히려 감소되는 경향이었다. 유화안정성은 유화력과 비슷한 크기로 나타나, $80^{\circ}C$에서 30분 가열에서도 이들 단백질이 열에 안정함을 보이었다. 기포 형성력은 참깨와 들깨 단백질이 대두 단백질에 비해 현저히 낮았으며, 0.1M NaCl과 0.5M NaCl 첨가시에는 모두 그 값이 증가되는 경향을 보이었다. 기포 안정성은 대두 단백질이 10분 이내에 크게 감소된 반면 참깨와 들깨 단백질은 30분까지 완만하게 감소하였다. 유지 흡착력은 들깨 단백질이 가장 높은 값을 보였고, 수분 흡착력은 시료간에 차이가 없었다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 일렉트렛트 및 응용기술
• /
• pp.31-35
• /
• 2002

It is hard to expect excellent electrical, mechanical and chemical properties from most of the composite materials presently used as insulators due to insufficient wettability property caused by the difference of interfacial properties between the matrix material and the reinforcer. Therefore, various interfacial coupling agents have been developed to improve the interfacial properties of composite materials. But if the wettable coupling agents are used outdoor for a long time, change in quality takes place in the coupling agents themselves, bringing about deterioration of the properties of the composite materials. In this study, composite materials were put to dry interfacial treatment by use of plasma technology. It has been presented that the optimum parameters for the best wettability of the samples at the time of generation of plasma were oxygen atmosphere, 0.1 torr of system pressure, 100 W of discharge power, and 3 minutes of discharge time. Also, the surface resistance rate and dielectric property were improved.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2005년도 추계학술대회 논문집
• /
• pp.295-298
• /
• 2005

This paper is concerned with the precision material property measurement of a micro metal thin foil that is used in MEMS technology. Since these MEMS components require great precision and accuracy, evaluation of reliability such as the lift cycle endurance test, impact test, and residual stress test is necessary for these components. However, in practice, real reliability tests are not easy to perform due to consideration of various factors. Rather than actual testing, it would be much easier to evaluate the reliability of components by the analytical approach. Although the analytical method is utilized by software tools, it is obviously necessary to acquire fundamental properties of materials through real test methods. In this paper, the oriented mechanical properties of aluminum thin foil are measured by nano scale material property measurement system.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 하계학술대회 논문집 A
• /
• pp.250-252
• /
• 2003

This paper is the estimation of the thermal property for the backfill materials according to the experimental measurements both a laboratory and field test.