• Journal of the Korean Vacuum Society
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• v.11 no.1
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• pp.68-75
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• 2002

It is observed the characteristic of the microwave air plasma in the wide range of the operating pressure, 1 mTorr ~ 760 Torr. The microwave air plasma was generated by an AC-type microwave source manufactured with a magnetron taken from a commertial microwave oven and the input power was fixed at 370 W. Characteristics of the plasmas were observed by an injection Langmuir probe and an OES(Optical Emission Spectroscopy). The breakdown electric field is drastically changed at 500 mTorr. For < 500 mTorr, the ratio of the breakdown electric field and the pressure decreased inversely to the pressure, $5.7\times10^4$V/m-Torr.However, the ratio increased linearly as 43 V/m-Torr for the operating pressure, > 500 mTorr. The minimum breakdown electric field was observed about 12. kV/m at 500 mTorr. It corresponds that the input frequency equals to the collision frequency. The effective collision cross section of the air at this pressure was calculated as $9.23\times10^{-l6}\textrm{cm}^2$.The results of the OES measurement revealed that the main ions were composed of the oxygen, argon, and nitrogen for > 500 mTorr. In contrast, only oxygen and argon ions were dominated for < 500 mTorr. ion temperature of oxygen (O(II)) in the air was decreased from about 1.2 eV to 0.5 eV as the pressure increased. Langmuir probe data shows that the plasma density for < 500 mTorr was higher that for > 500 mTorr.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1203-1206
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• 2005

Electron temperature and plasma density in coplanar alternating-current plasma display panels (AC-PDP's) have been experimentally investigated in accordance with discharge time by a micro-probe in this experiment. The resolution of a step mortor to move in micro-Langmuir probe is 10um.[1-3] The used gas in this experiment is He-Ne-Xe (4%) mixure gas. And sustain voltage is 320V which is above of firing voltage for degradation. The electron temperature and plasma density can be obtained from current-voltage (I-V) characteristics of micro Langmuir probe, in which negative to positive bias voltage was applied to the probe. And Efficiency is calculated by formula related discharge power and light emission. Those experiments operated as various discharge time ($0{\sim}72$ Hours). As a result of this experiment, Electron Temperature was increased from 2eV to 5eV after discharge running time of 20 hours and saturates beyond 20 hours. The plasma density is inversely proportional to the square root of electron temperature. So the plasma density was decreased from $1.8{\times}10^{12}cm^{-3}$ to $8{\times}10^{11}cm^{-3}$ at above discharge running time. And the Efficiency was reduced to 70% at 60hours of discharge running time.

• Korean journal of applied entomology
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• v.33 no.1
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• pp.26-32
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• 1994

Electroantennography, wind tunnel observation, and field trapping experiments were carried out to investigate the biological activity of synthetic sex pheromone in the onental tobacco budworm. Heli-couerpa assulta. Two major sex pheromone components of H. assulta, Z9-16' Ald and Z11-16: Ald. elicited a big EAG response in male, but not in female Their mIXture ratios did not give much influence on EAG size Fema]e H assulta showed a great EAG response only to its host plant e extract. EAG size also increased with the amount of mixture from 001 to 10 [lg but rather decreased w when the amount was 1 00 $\mug$. H. assulta always revealed a series of stereotyped behavior in a wind tunnel. The behavioral response was different when the males were stimulated with the sex pheromone containing some minor components, 16: AId and Z9.16: Ac, or being different in mixing ratios of the two major components. The best ratio of the sex phemmone components for a attracting H assulta male adults was 20-25: 1 between Z9-16: Aid and Z11-16: Ald in net house a and red pepper field experiments in Korea When the lure contamed Z9-16: OH, attracting power rapidly decreased. The synthetic sex pheromone showed a strong attraction when compared to virgin females

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.4
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• pp.293-299
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• 2002

The anchovy scoop net fishery is one of the important in the South sea and coastal of Jeju of Korea. They are using incandescent lamp as a fishing lamp at night to gather anchovy shoals in the water surface. Fishing lamp (AC 100 V 500 W$\times$2~3 or AC 100 V 1 ㎾$\times$1) was installed at 1 m ahead of the prow and 1.5 m height from the water surface. The fishing lamp let anchovy shoals rise to the water surface and are attracted to bag net. On this study, the distribution of submarine illumination of 1㎾ and 2 ㎾ incandescent lamp were analyzed and discussed to investigate the ability of fishing lamp which can gather anchovy shoals effectively. The submarine illumination of incandescent lamp showed peak in wave length 690 nm. The relationship between submarine illumination (L) and water depth (Z) of 1 ㎾ and 2 ㎾ incandescent lamp in vertical light is 1 ㎾ : L = 3851. 9 $e^{-1.4587Z}$ $R^2$=0.9952 2 ㎾ : L= 8211.9 $e^{-1.2852Z}$ $R^2$=0.9977 The submarine illumination of 2 ㎾ incandescent lamp of 0～4 m layers appeared to be 3 to 4 times higher than 1 ㎾ incandescent lamp, and in more deep layers than 6 m appeared to be equal value of each lamp. The light of incandescent lamp (1 ㎾) pass through much better into vertical direction than horizontal, and submarine illumination of 20 m layers was 1.0 l$\chi$. Therefore, fishing lamp power is thought that 1 ㎾ incandescent lamp is more efficient than 2 ㎾ to gather anchovy shoals in depth of 15~20 m to water surface.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.6
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• pp.117-125
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• 2007

Recently, a fuel cell with low voltage and high current output characteristics is remarkable for new generation system. It needs both a DC-DC step-up converter and DC-AC inverter to be used in fuel cell generation system. Therefor, this paper, consists of an isolated DC-DC converter to boost the fuel cell voltage 380[VDC] and a PWM inverter with LC filter to convent the DC voltage to single-phase 220[VAC]. Expressly, The fuel cell system which it proposes DC-DC the efficient converter used PWM the phase transient control law and it depended to portion resonance ZVS switching, loss peek voltage and electric current of realization under make schedule, switching frequency anger and the switch reduction. And mind benevolence it sprouted 2 in stop circuit and it added and a direct current voltage and the electric current where the ingredient is reduced in load side ripple stable under make whom it will be able to supply. Besides the efficiency of 92[%]is obtained over the wide output voltage regulation ranges and load variations. Also, under make over together the result leads simulation and test, the propriety confirmation.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.229-229
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• 1999

교류형 플라즈마 방전 표시기(AC Plasma Display Panel, AC PDP)의 구동에서의 방전 현상은 기입방전, 유지방전, 소거 방전이 있다. 이중 유지 방전은 표시장치로서의 휘도와 계조의 표현을 위한 방전으로 표시기로서의 효율을 결정하게 된다. 본 연구에서는 유지 방전 전압의 상승 시간의 변화에 따른 방전현상과 휘도, 효율의 변화를 살펴 보았다. 방전 현상에서의 가장 큰 변화는 교류형 플라즈마 방전 표시기의 방전 개시 전압과 방전 유지 전압의 변화이다. 유지 전압의 상승시간이 증가할수록 방전 개시 전압과 방전 유지 전압의 변화이다. 유지 전압의 상승 시간이 증가할수록 방전 개시 전압과 방전 유지 전압의 차(sustain margin)는 감소하여 상승 시간이 1$\mu$s/100V 이상의 영역에서는 방전 개시 전압과 방전 유지 전압이 차이가 없어지게 된다. 이는 방전 유지 전극 위의 유전체에 쌓이게 되는 벽전하(wall charge) 양의 감소에 의한 방전 약화의 영향을 보여질 수 있다. 그러나 방전 유지 전압의 형태와 전류의 시간적인 변화를 살펴보면 이러한 약한 방전은 벽전하의 감소에 의한 방전 시의 전계 감소보다는 방전 전류의 발생 시간이 방전 전압이 증가하여 최고점에 이르지 못한 시간에 위치하여 방전이 형성될 때의 전계가 강하지 못하기 때문인 것을 알 수 있다. 방전 전류를 측정한 결과에 의하면 방전 전류의 시작은 변위 전류가 흐르고 난 후부터 시작되며 그 결과 방전 전류가 최고점에 도달하는 시간은 방전 전압 상승 시간이 길어질수록 낮은 전압에서 형성되게 된다. 또한 방전 유지 전압의 상승 시간이 길어질수록 플라즈마 방전표시기의 휘도와 효율은 낮아지고 이 결과 또한 약한 전계에서의 방전에 의한 결과로 생각되어진다.플라즈마의 강도값을 입력하여 플라즈마의 radiation을 검출하고, 스퍼터링 공정중 실질적인 in-situ 정보로 이용하였다. PEM을 통하여 In/Sn의 플라즈마 강도변화를 조사하였다. 초기 In/Sn의 플라즈마 강도(intensity)는 강도를 100하여, 산소를 주입한 결과, plasma intensity가 35 줄어들었고, 이때 우수한 ITO 박막을 얻을 수 있었다. Pulsed DC power를 사용하여 아크 현상을 방지하였다. PET 상에 coating 된 ITO 박막의 표면저항과 광투과도는 4-point prove와 spectrophotometer를 이용하여 분석하였고, AES로 박막의 두께에 따른 성분비를 확인하였다. ITO 박막의 광투과도는 산소의 유량과 sputter 된 In/Sn ion의 plasma emission peak에 따라 72%-92%까지 변화하였으며, 저항은 37$\Omega$/$\square$ 이상을 나타내었다. 박막의 Sn/In atomic ratio는 0.12, O/In의 비율은 In2O3의 화학양론적 비율인 1.5보다 작은 1.3을 나타내었다.로 보인다.하면 수평축과 수직축의 분산 장벽의 비에 따라 cluster의 두께비가 달라지는 성장을 볼 수 있었고, 한 축 방향으로의 팔 넓이는 fcc(100) 표면의 경우 동일한 Ed+Ep값에 대응하는 팔 넓이와 거의 동일한 결과가 나타나는 것을 볼 수 있다. 따라서 이러한 비대칭적인 모양을 가지는 성장의 경우도 cluster 밀도, cluster 모양, cluster의 양 축 방향 길이 비, 양 축 방향의 평균 팔 넓이로부터 각 축 방향의 분산 장벽을 얻어낼 수 있을 것으로 보인다. 기대할 수 있는 여러 장점들을 보고하고자 한다.성이 우수한 시

• Korean Chemical Engineering Research
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• v.43 no.3
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• pp.425-431
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• 2005

New type of supercapacitor using high surface area activated carbons mixed with high conductivity polypyrrole (Ppy) has been prepared in order to achieve low impedance and high energy density. Mixed carbons of BP-20 and MSP-20 were used as the active electrode material, and polypyrrole doped with 2-naphthalenesulfonic acid (2-NSA) and carbon black (Super P) as conducting agents were added to activated carbons in order to enhance good electric conductivity. Electrodes prepared with the activated electrode materials and the conducting agents were added to a solution of organic binder [P(VdF-co-HFP) / NMP]. The ratio of optimum electrode composition was 78 : 17 : 5 wt.％ of (MSP20 : BP-20=1 : 1), (Super P : Ppy=10 : 7) and P(VdF-co-HFP) respectively. The performance of unit cell with addition of 7 wt％ Ppy have shown specific capacitance of 28.02 F/g, DC-ESR of $1.34{\Omega}$, AC-ESR of $0.36{\Omega}$, specific energy of 19.87 Wh/kg and specific power of 9.77 kW/kg. With addition of Ppy, quick charge-discharge of unit cell was possible because of low ESR, low charge transfer resistance and quick reaction rate. And good stability up to 500 chargedischarge cycles were retained about 80％ of their original capacity. It was concluded that the specific capacitance originated highly from compound phenomena of the pseudocapacitance by oxidation-reduction of polypyrrole and the nonfaradaic capacitance by adsorption-desorption of activated carbons.

• Korean Chemical Engineering Research
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• v.51 no.3
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• pp.308-312
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• 2013

Active carbons with high specific surface area and micro pore structure were prepared from the coconut shell char using the chemical activation method of NaOH. The preparation process has been optimized through the analysis of experimental variables such as activating chemical agents to char ratio and the flow rate of gas during carbonization. The active carbons with the surface area (2,481 $m^2/g$) and mean pore size (2.32 nm) were obtained by chemical activation with NaOH. The electrochemical performances of hybrid capacitor were investigated using $LiMn_2O_4$, $LiCoO_2$ as the positive electrode and prepared active carbon as the negative electrode. The electrochemical behaviors of hybrid capacitor using organic electrolytes ($LiPF_6$, $TEABF_4$) were characterized by constant current charge/discharge, cyclic voltammetry, cycle and leakage tests. The hybrid capacitor using $LiMn_2O_4$/AC electrodes had better capacitance than other hybrid systems and was able to deliver a specific energy as high as 131 Wh/kg at a specific power of 1,448 W/kg.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.7
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• pp.710-721
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• 2013

The noise prediction of motor driving system is one of the most important parts in EV/HEV, as the number of power electronic devices increases. This paper describes the mechanism of noise making process and proposes a simulation model of motor driving system for the prediction of the conducted noise. Theoretical calculations and model based simulations were carried out. DOD-dependent-battery parameters were extracted by AC analysis, and an inverter model including dynamic diode was used. Furthermore, 2-D EM tool was used for the motor modeling and was combined with the circuit models of battery and inverter. The simulated voltages, currents and spectrums in the motor driving system showed qualitatively meaningful results, suggesting the validness of the suggested modeling methods.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.3
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• pp.257-265
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• 2016

In this study, an optimal design for motor-driven track type traveling system applied into high clearance working machineries in orchard is proposed. Tractive performance and hill climbing ability were predicted and evaluated for the optimal motor traveling system by taking into account of soil characteristics in orchard utilizing the high clearance working machineries. Design criteria for tractive performance were based on the traction force calculated from tractive effort subtracted by motion resistance, while hill climbing ability had its design criteria that fulfill the climbing 20% slope ground at a speed of 3km/h. Based on the evaluation results of traction and climbing ability, two DC48V, 4500rpm, 1.6kW AC motors were independently applied to both left and right side of orbits; each motor is designed to transmit power on driving sprocket of track type traveling system via 50:1 reduction gear ratio. The motor-driven track type traveling system developed in the study found to have 396 kgf of tractive force, which is 12.5% higher than climbing resistance at orchard soil having 20% slope ground (352 kgf), demonstrating sufficient tractive performance and hill climbing ability.