• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.3
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• pp.53-60
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• 2012

The fall-of-potential method is commonly used in measuring the ground resistance of large-scaled grounding system and the current and potential auxiliary electrodes are horizontally arranged. Because the distances between the ground grid to be tested and auxiliary electrodes are limited in downtown areas, it is very difficult to measure accurately the ground resistance of large-scaled grounding system. In this paper, the fall-of-potential method of measuring the ground resistance with the vertically-placed current and potential auxiliary electrodes was examined and discussed. The validity and good accuracy of the proposed method of measuring the ground resistance were confirmed through various simulations and actual tests carried out in uniform and two-layer soil structures.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.01a
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• pp.23-24
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• 2014

본 논문에서는 최근 모바일 기기에서 많이 사용되고 있는 마름모 패턴의 터치스크린패널(TSP; Touch Screen Pannel)에서 정확한 터치 위치를 획득하는 방법을 제안한다. 가로와 세로로 배치된 ITO 투명전극필름은 사용자의 터치로 인하여 변화된 정전용량(mutual capacitance)을 측정하여 터치위치를 파악한다. 그러나 터치패턴의 모양과 손가락의 크기에 따라서 측정되는 상호정전용량의 값에 차이가 발생하며 이 차이는 터치위치 계산에 영향을 미쳐서 정확한 터치위치를 획득하기 어렵게 한다. 이러한 결과로 TSP 상에서 직선을 그어도 측정된 터치 값은 S자 형태로 나타난다. 본 논문에서는 이러한 문제를 완화하기 위하여 Matlab 상에서 터치상황을 시뮬레이션하고 이를 이용하여 터치위치를 보상하여 보다 더 정확한 터치위치를 구하는 방법을 제안한다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.457-458
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• 2007

We investigated a resistor network model for the horizontal AlInGaN LED. Adding the proposed current density dependent relative quantum efficiency, the power simulation can be also obtained. Comparing the simulation and the measurement results for the LED with the size of $350{\mu}m$, the model is reasonable to simulate the forward voltage and the light output power. Using this model we investigated the optimization of the position and the number of the finger electrodes in a given chip area. It shows that the center disposition of the p-finger electrode in p-area is optimal for the voltage and best for the power. And the minimum number of the n-finger electrodes is best for the power.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.1-7
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• 2018

In a microcolumn, a miniaturized electrostatic deflector is often adopted to scan an electron beam. Usually, a double octupole deflector is used because it can avoid excessive spherical aberrations by controlling the electron beam path close to the optical axis of the objective lens and has a wide scan field. Studies on microcolumns have been performed to improve the low throughput of an electron column through multiple column applications. On the other hand, as the number of microcolumns increases, the number of wires connected to the components of the microcolumn increases. This will result in practical problems during the process of connecting the wires to electronic controllers outside of the vacuum chamber. To reduce this problem, modified quadrupole and octupole deflectors were examined through simulation analysis by selecting an ultraminiaturized microcolumn with the Einzel lens eliminated. The modified deflectors were designed changing the size of each electrode of the conventional Si octupole deflector. The variations of the scan field and electric field strength were studied by changing the size of active electrodes to which the deflection voltage was to be applied. The scan field increased linearly with increasing deflection voltage. The scan field of the quadrupole deflector and the electric field strength at the center were calculated to be approximately 1.3 ~ 2.0 times larger than those of the octupole deflector depending on the electrode size.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.9 no.1
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• pp.47-53
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• 1995

In this paper, the characteristics of breakdown voltage($\textrm{V}_{Brms}$) -temperature(T) for air insulated power installation in flowing air with variation of T(30[$^{\circ}C$] -180[$^{\circ}C$]) are presented. To study these subjects, needle-to-needle gap in the circular pipe(inner diameter 5[cm]) are used. Also, theories of gas discharge and hydrodynamics in pipe were used to analysis for the characteristics. The $\textrm{V}_{Brms}$ is proportional to flow velocity. At high velocity, $\textrm{V}_{Brms}$ is described the saturation. At high T(180[$^{\circ}C$]), $\textrm{V}_{Brms}$ is about 4.7(kV] lower than low T(30[$^{\circ}C$]). The empirical equation obtained from this study is $\textrm{V}_{Brms}=A\times{Log[Re}+B$. Where A, B : Constant.

• Journal of Sensor Science and Technology
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• v.8 no.1
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• pp.32-37
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• 1999

A capacitance-type humidity sensor with mesa structure in which porous silicon layer is used as humidity-sensing material is developed and its humidity sensing properties are measured. This sensor has a structure where two electrodes are set on the up-side of the wafer against the past typical structure having these electrodes on the up and down-side of the wafer. Therefore, the sensor can be fabricated monolithically to be more compatible with the IC process technology, and is possible to detect more correct output capacitance by removing the effect of the parasitic capacitance from the bottom layer and other junctions. To do this, the sensor was fabricated using process such as localized formation of porous silicon, oxidation of porous silicon layer, and etching of oxidized porous silicon layer. From the completed samples, the dependence of capacitance on the relative humidity of 55 to 90% more was measured at room temperature. As the result, the measured capacitance increased monotonously higher at the low frequency of 120 Hz, where the capacitance was observed to increase over 300%.

• Journal of Korean Physical Therapy Science
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• v.4 no.2
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• pp.399-403
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• 1997

The purpose of this study was to determine the efficacy of electrode placement on procaine iontophoresis. Thirty-three healthy students with an age range of 19 to 34 years, were participated in this study. The subjects were randomly assigned into 3 groups. Each subjects received iontophoresis on the proximal 1/3 of volar surface of dominant forearm with soft cotton pad($3.5{\times}3.5cm$) soaked in 2 ml of 4% procaine hydrochloride (pH 5.1) at 4 mA for 10 minutes(total current 40 mA min) of anodal DC. In transversal electrode placement(TEP) group, dispersive electrode was placed on the proximal 1/3 of dorsal surface of the forearm. In longitudinal electrode placement (LEP) group and control group, dispersive electrode were placed on the distal 1/3 of volar surface of the forearm. After procaine iontophoresis, duration of anesthesia were evaluated at five minutes intervals on five random locations in the iontophoretically area using a 21-gauge sterile hypodermic needle pressed with 1 mm invagination until return the sharp pin-pricking pain sensation. The data were ana lysed with one-way ANOVA to determine signific~nt differences between groups. The results showed significantly differences in the local anesthetic duration between the 3 groups(p<0.001). The anesthetic durations of TEP group and LEP group were significantly longer when compared with control group(p<0.05). Anesthetic durations of TEP group and LEP group were not significantly difference, but anesthetic duration of LEP group tends to longer than TEP group. In view of these results, clinicians should consider the electrode placement method when performing the iontophoresis.

• Progress in Medical Physics
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• v.7 no.2
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• pp.29-40
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• 1996

We had designed and made the cylindrical ionization chamber which operated above 5 mR/h. Using commercial electrometer, we investigated the characterictic of charge collection in the ion chamber. The active volume was 190.4㎤ and overall length and diameter in the chamber was 15.5cm, 5.22cm, respectively. The chamber had three electrodes(inner, central, wall electrode). And background current was 8.39${\times}$10$\^$-14/${\pm}$1.5${\times}$10$\^$-15/A to arrange the electrodes which were coaxial in chamber axis. The collection efficiency of chamber for Cs$\^$137/ was 99.7％ when the opreating voltage was applied 400V. Comparing with the commertial dosimetry system, the exposure calibration constant was 4.531${\times}$19$\^$7/R/C. By normalizing to CS$\_$137/ the relative energy response of the chamber was 1.30 for Am$\_$24/, 1.05 for C0$\_$60/, respectively. When the irrarition tranversed to the chamber axis, the isotropic effect of the chamber was not considerable.

• Journal of the Korea Society of Computer and Information
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• v.17 no.9
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• pp.149-156
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• 2012

The Fabric Electrode was proposed for the effective production of the display based on electrowetting in this paper and designed the source driver of flexible display which could be driven by the electrowetting cell. The electrowetting cell matrix was implemented on the substrate(PET) by imprinting. The driver fabric, wetting electrode fabric and conductive fabric was placed horizontally and vertically in the groove between cell matrix and the electrowetting cell matrix can be driven by the cross-point as electric connection. The integration density of driver module is decreased because using the R/2R DAC module per channel in the conventional method. The proposed method could utilize the effective production process and reduce the production price of a display panel. The source driver which consume lower power and can increase the integration density because of reducing the number of driver device per channel was designed and evaluate the driver operation by the simulation using the VHDL programming in this paper.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.4
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• pp.468-480
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• 1993

In this paper, at first, the characteristics of double mode SAW (DMS) resonator are analysed by applying the wave guide model and coupled mode theory to 1-port resonator. The DMS resonators (2-pole), which are arranged in a close, parallel configuration of two identical 1-port resonators on a single plate, and 4-pole DMS filters are designed and fabricated at the center frequency of 150.15 MHz with 3-dB bandwidth of 80 KHz. The empirical design characteristics are obtained from the comparison of experimental and theoretical values resulted from several fabrications, and the narrow bandpass filters are implemented on the basis of the above empirical results, which can be used to mobile communication systems. A ST-cut quartz substrate is selected for the stable temperature-frequence characteristics, and high resolution photolithography is applied to the fabrication of filter to get the fine electrode patterns.