• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.232.1-232.1
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• 2013

본 연구에서는 asymmetric과 symmetric 구조의 n채널 MOSFET 소자의 성능 평가에 관한 실험을 진행하였다. 소자의 성능 평가에 있어 아날로그 회로에서의 DC 이득은 중요한 파라미터 중 하나 이다. 따라서 본 연구에서는 gm/ID 측정법을 이용하여 각 소자의 DC 이득 특성을 분석하였다. 게이트 전압에 따른 드레인 전류-드레인 전압 특성 곡선으로부터 early voltage 값을 추출하였다. 이후 최종적으로 수치적 계산을 통해 DC 이득 값을 추출하였다. 실험 결과 asymmetric과 symmetric 소자의 경우 early voltage 값이 각각 -34 V와 -15 V였으며 따라서 DC 이득 특성 또한 asymmetric 소자의 경우가 우수한 것을 확인하였다.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.37 no.2
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• pp.6-11
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• 2000

In this paper, suggesting a new linearly -graded depletion edge approximation, the current-voltage characteristics of an n-type short-channel GaAs MESFET device has been analyzed by solving the two dimensional Poisson's equation in the depletion region. In this model, the expressions for the threshold voltage, the source and the drain ohmic resistance, and the drain current were derived. As a result, typical Early effect of a short channel device was shown and the ohmic voltage drop by source and drain contact resistances could be explained. Furthermore our model could analyze both the short-channel device and the long-channel device in a unified manner.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.184.1-184.1
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• 2013

It is generally known that electron beam has sterilization effects and can activate plant germination and growth. Compared to electron beam, electrical pulse has not been frequently studied with respect to the biological application. In this study, we have analyzed the effects of high voltage pulse on seed germination and growth using various plant species. We have used the high voltage generator for examining seed's responses to the high voltage pulse. The operating voltage and currents of the generator are about 300 kV and 30 kA, respectively. Pulse width is 60 ns. High voltage pulse has slightly activated germination and growth of radish during early stage. Various levels of germination and growth are observed in different plant species after treated with high voltage pulse.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.2
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• pp.339-344
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• 2017

A novel structure of phase locked loop (PLL) which has small size and fast locking time with Early-late detector, Duty-rate modulator, and Lock status indicator (LSI) is proposed in this paper. The area of loop filter usually occupying the larger portion of the chip is minimized using a single small capacitor. While the conventional PLL with a single capacitor loop filter cannot work stably, the proposed PLL with two charge pumps works stably because the output voltage waveform of the proposed a single capacitor loop filter is the same as the output voltage waveform of the conventional 2nd-order loop filter. The two charge pumps are controlled by the Early-late detector which detects early-late status of UP and DN signals, and Duty-rate modulator which generates a steady duty-rate signal. Fast locking time is achieved using LSI. It has been simulated and proved by HSPICE in a CMOS $0.18{\mu}m$ 1.8V process.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.8
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• pp.1218-1223
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• 2003

The effects of type (high and low voltages) and time (3, 40 and 60 min postmortem) of stimulation on drip loss and meat color at 24 h post-mortem were determined on M. longissimus dorsi of 38 crossbred steers and heifers. In addition, the effect of pH early postmortem (70 min postmortem) on the rate and extend of meat tenderization was examined. Either high or low voltage stimulation at 3 min showed a tendency for faster pH decline (p=0.052) and higher drip loss (p=0.08), and improved the color dimensions of L*, a* and b* (p<0.01), compared to stimulation at 40 min. This was equivalent to approximately one unit of an AUSMEAT color chip. On the other hand, although there were significant differences in pH decline between high voltage stimulation at 40 and 60 min, and between low voltage stimulation at 40 min and control sides, drip loss and meat color did not differ significantly (p>0.05). The results suggested that early application of stimulation, regardless of type of stimulation, improved overall meat color at 24 h postmortem through its effect on faster glycolysing rate. However, if the pH decline was moderate, the benefit of electrical stimulation on meat color was not apparent. An intermediate pH decline resulted in the lowest shear force. Due to differential ageing rates the optimum pH at 70 min postmortem increased with ageing time from 5.96, 6.07, 6.12 and 6.14 for 1, 3, 7 and 14 days postmortem, respectively. This implied that a small difference in the rate of pH decline was important, especially carcasses stimulated for very early postmortem, and the optimum rate of pH decline varied with intended ageing period. The study suggests that the beneficial or adverse effects of electrical stimulation on drip loss, meat color and tenderness is determined by the rate of pH decline, rather than by stimulation treatment and time of application per se.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.107-111
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• 1996

In this paper, the voltage monitoring system is designed to monitor the outage and voltage fluctuation by using a dial-up telephone. The master station receives tire outage signal-such as interruption and voltage sag etc. - from the remote in on-line of real-time. The SCC(Serial Communication Controller) is adapted to monitor voltages multiple clients(about 256 clients) simultaneously. The voltage fluctuation in a normal range shall be transmitted to the master station, at early morning the clients use the telephone less frequently. The operating system shall be "window 95" and the database is programmed in Visual-basic for a easy analysis of voltage fluctuation.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.4
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• pp.99-106
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• 2010

A piezo-driven injector was applied with a purpose to evaluate the effect of induced voltage on spray characteristics. For this, injection rate, macroscopic imaging, ambient gas entrainment and particle sizing were carried out. It was shown that initial slope of injection rate was steeper as induced voltage increased, while slope of injection rate became mostly constant with fully opened needle. From macroscopoic imaging, longer spray tip penetration was produced with higher induced voltage. Moreover, wider spray angle was detected in the early stage of spray development, when higher induced voltage was applied. Ambient air entrainment rate was increased and particle size was reduced with higher induced voltage.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.522-523
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• 2014

Analysis of faults in induction motors has become a major field of research due to importance of loss and damage reduction and maximum online performance of motors. There are several methods to analyze the faults in an induction motor from conventional Fourier transform to modern decision-making neural networks. Considering detectability of fault among all methods, a new fault detection solution has been proposed; it is called as frequency-domain Discrete Wavelet Transform (FD-DWT). In this method, the stator current is decomposed through series of low- and high-pass filters and consequently, the fault characteristics are more visible, because additional components have been reduced. The objective of this paper is early detection of input voltage unbalance in induction motor using wavelet transform in frequency domain. Experimental results show the effectiveness of the proposed method in early detection of faults.

• Journal of the Korean Society of Safety
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• v.29 no.6
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• pp.46-48
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• 2014

This paper compared and demonstrated the performance of the earth plate for conventional type and early streamer discharging type developed a new plate in order to improve the performance of the ground plate for use in grounding. The results obtained are shown below; early streamer discharge earth plate was high 5 kV on DC flashover voltage and corona discharge current was higher than about 2 times under the same test conditions compared to the conventional earth plate. From the experiential result, streamer discharge earth plate had a function of rapid inflow/out flow than the general ground plane because of by corona discharge current to be generated in the sharp serrated in formed the ground plane when strike current occurred. In the future, the newly developed early streamer discharge ground plate would be beneficial for grounding work to be widely used to promote the convenience and economy of construction.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.12
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• pp.627-632
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• 2001

There are claims that ESE(Early streamer emission) Air terminals offer a vastly increased zone of protection over that of traditional lightning rods by causing the emission of an upward streamer/leader that will propagate towards the tip of downward leader at an early stage in the attachment process than would occur for a simple rod in the same geometrical configurations. This paper shows the results of comparing test a particular type of ESE air terminals with a simple rod conducted in the KEH HV laboratory, which are lightning impulse voltage test, flashover direction test and corona emission current measurement. The results from this test show a completely random scattering of flashovers to the conventional and ESE air terminals under identical electrics] and geometrical conditions, and thus shows no advantage of one terminal over the other.