• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.490-490
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• 2013

In semiconductor industry, it is expected that plasma process which use 450 mm source will be used at next generation. However, main obstacle of the large area plasma source is plasma uniformity from it. When electrode is enlarged, field difference between center area and side area reduces the plasma uniformity [1-3]. Therefore we investigate multi-electrode which diminish this field difference.We designed two multi-electrode models. One has two segments and the other has five segments. Each multi-electrode model is connected with two power generator and two matchers. One generator and one matcher is connected with center electrode part. The other one generator and the other one matcher is connected with side electrode part. The ion density is measured at 29 points by using floating harmonic method [4-6]. After measuring the data of each multi-electrode model, we discuss the difference of profile between two models' data.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.2
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• pp.224-229
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• 1996

Performance characteristics of single cell in phosphoric acid fuel cell were studied for various electrode fabrication parameters such as teflon content, electrode structure, thickness of electrocatalyst layer, platinum content and electrode area. The performance of single cell was decided from the measured voltage-current through a load change. The electrode of 40wt.% teflon exhibited high initial performance of single cell, but in the long term operation, the cell performance of 45 wt.% teflon was better. Also the single cell appeared good performance in case of electrodes with duplicate structure, thin electrocatalyst in thickness, more platinum content, and small area. These results of cell performance were discussed as related to the electrolyte flooding, formation of 3 phase boundary area, internal resistance of electrode, and microstructure of electrode.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.5
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• pp.58-64
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• 2000

This paper proposes a method for determining optimal EDM parameters based on discharge area from the physical model of a tool electrode. Main parameters, which affect the EDM performance, are peak value of currents, pulse-on time, and pulse-off time. Such parameters are closely dependent on the discharge area in EDM process. In this paper the discharge area is estimated from the CMM scanning data to the tool electrode. The method is very useful when any geometric information to the tool electrode is not provided from tool modeler or producer. The method consists of following four steps. First a triangulation mesh is constructed from the CMM data. Secondly, the z-map is modeled from the triangulated mesh. Thirdly, the discharge area is estimated from intersection between the z-map model and a z-height plane. Finally, the machining parameters are easily calculated by some known EDM equations to the discharge area. An example is introduced to show that the machining parameters are calculated from the CMM data to a tool electrode.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.6
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• pp.883-888
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• 2012

Anode electrode is one of the most important factors in microbial fuel cell (MFC). This study was conducted to investigate the effects of mediator as methylene blue (MB) and electrode surface area on the power density of MFC with sponge and carbon nano tube (CNT) electrode (SC). The SC electrode with MB (MC) showed the maximum power density increased from 74.0 $mW/m^2$ to 143.1 $mW/m^2$. The grid shaped sponge and CNT (GSC) electrode showed the maximum power density of 209.2 $mW/m^2$ due to the increase of surface area from 88.0 to 152.0 $cm^2$. The GSC electrode with MB (GMC) revealed the maximum power density of 384.9 $mW/m^2$ which was 5.2 times higher than that obtained from the MFC with SC. Therefore MB and increase of surface area led to enhance the performance of microbial fuel cell such as power density.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.69-72
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• 2008

A new electrode structure is proposed in this paper which can increase the discharge efficiency of plasma display panels and also decrease the panel capacitance by decreasing the electrode area effectively. Even with the decreased electrode area, the proposed structure could suppress the requirement for increasing the voltage and improve efficiency by limiting the discharge current.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.2
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• pp.115-120
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• 2014

Photo electrode is an important component for DSSC. DSSCs electrical characteristics and efficiencies fabricated with different $TiO_2$ photo electrodes thickness and modified phoro electrode surface area were studied. $11{\mu}m$ $TiO_2$ photo electrode shows a 4.956% efficiency. The highest short circuit current density was a $9.949mA/cm^2$. Efficiencies and short circuit current density increased as tape casting thickness decreased. Modified surface area of the photo electrode by needle stamp processing were studied. 200 times needle stamp processing on photo electrodes shows a highest 5.168% efficiency. Also the short circuit current density was a $10.261mA/cm^2$.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.478-478
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• 2012

Recently, there are many researches in order to increase the deposition rate (D/R) and improve film uniformity and quality in the deposition of microcrystalline silicon thin film. These two factors are the most important issues in the fabrication of the thin film solar cell, and for the purpose of that, several process conditions, including the large area electrode (more than 1.1 X 1.3 (m2)), higher pressure (1 ~ 10 (Torr)), and very high frequency regime (VHF, 40 ~ 100 (MHz)), have been needed. But, in the case of large-area capacitively coupled discharges (CCP) driven at frequencies higher than the usual RF (13.56 (MHz)) frequency, the standing wave and skin effects should be the critical problems for obtaining the good plasma uniformity, and the ion damage on the thin film layer due to the high voltage between the substrate and the bulk plasma might cause the defects which degrade the film quality. In this study, we will propose the new concept of the large-area multi-electrode (a new multi-electrode concept for the large-area plasma source), which consists of a series of electrodes and grounds arranged by turns. The experimental results with this new electrode showed the processing performances of high D/R (1 ~ 2 (nm/sec)), controllable crystallinity (~70% and controllable), and good uniformity (less than 10%) at the conditions of the relatively high frequency of 40 MHz in the large-area electrode of 280 X 540 mm2. And, we also observed the SEM images of the deposited thin film at the conditions of peeling, normal microcrystalline, and powder formation, and discussed the mechanisms of the crystal formation and voids generation in the film in order to try the enhancement of the film quality compared to the cases of normal VHF capacitive discharges. Also, we will discuss the relation between the processing parameters (including gap length between electrode and substrate, operating pressure) and the processing results (D/R and crystallinity) with the process condition map for ${\mu}c$-Si:H formation at a fixed input power and gas flow rate. Finally, we will discuss the potential of the multi-electrode of the 3.5G-class large-area plasma processing (650 X 550 (mm2) to the possibility of the expansion of the new electrode concept to 8G class large-area plasma processing and the additional issues in order to improve the process efficiency.

• Journal of Ocean Engineering and Technology
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• v.19 no.2 s.63
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• pp.53-59
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• 2005

The effect of pH on the corrosion characteristics in the dissimilar friction welded zone of IN713LC-SCM440 in the loaded torsional stress was studied. The corrosion experiment was performed for 120 hours on the specimens with five steps of pH. The surface corrosion pattern of the SCM440 area showed global corrosion and narrow pitting, which was caused by galvanic corrosion between friction welded IN713LC and SCM440, but corrosion did not proceeded from the IN713LC area. The average relative electrode potential gradually tends to decrease with the elapse of the immersion time in the acidity area. The average corrosion current also gradually tend to decrease The corrosion rate showed a larger value when the average relative electrode potential was higher and the average relative current was lower. The corrosion rate showed a larger value when the average relative electrode potential was higher in the acidity area, and it showed large when the average relative electrode potential was lower in the alkalinity area.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.10 no.2
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• pp.37-42
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• 2012

Purpose : This study is to examine the effect of electrode size during transcranial direct current stimulation on hand function. Methods : By randomly assigning 26 right hand dominant subjects to two groups (I: carbon rubber electrode / II: disposable circular self-adhesive electrodes) with 13 subjects in each group depending on the electrode size, a positive electrodeof transcranial direct current stimulation was placed on the primary motor area (C4) and a negative electrode was placed on the left primary motor area (C3) and the stimulation was applied for 20 minutes.Hand function assessment before and after transcranial direct current stimulation were measured with JTT (Jebsen-Taylor hand function test). Results : According to hand function assessment by JTT, there were no interactions on both hands, and statistically significant differences according to time appeared in the main effect test. Conclusion : Regardless of the electrode size, it appears that transcranial direct current stimulation on the primary motor area activated hand function affected.

• Journal of Korean Physical Therapy Science
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• v.10 no.2
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• pp.193-198
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• 2003

Acupuncture has been used as a clinical treatment in Oriental medicine for various diseases. In the present study was carried out to investigate the effects of acupuncture and electrical stimulation on the change neuronal nitric oxide synthase(nNOS) immunoreactive cells in the periaqueductal gray(PAG) area of the male SD rats. Enhanced expression of nNOS was detected in the dorsolateral-PAG(DL-PAG) area of rat with stress by fixed body, and acupuncture and needle electrode electrical stimulation groups at Hapgok like acupoint decreased the stress-induced enhancement in the expression of nNOS. The present results demonstrate that acupuncture and needle electrode electrical stimulation is effective in the modulation of expression of nNOS in the DL-PAG area under stress conditions.