• Transactions on Electrical and Electronic Materials
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• v.14 no.3
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• pp.116-120
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• 2013

This paper proposes a novel RF MEMS dc-contact switch with stiff membrane on a quartz substrate. The uniqueness of this work lies in the utilization of a seesaw mechanism to restore the movable part to its rest position. The switching action is done by using separate pull-down and pull-up electrodes, and hence operation of the switch does not rely on the elastic recovery force of the membrane. One of the main problems faced by electrostatically actuated MEMS switches is the high operational voltages, which results from bending of the membrane, due to internal stress gradient. This is resolved by using a stiff and thick membrane. This membrane consists of flexible meanders, for easy movement between the two states. The device operates with an actuation voltage of 6.43 V, an insertion loss of -0.047 dB and isolation of -51.82 dB at 2 GHz.

• New & Renewable Energy
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• v.4 no.1
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• pp.31-36
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• 2008

Stainless steels have been widely considered as metallic bipolar plates, due to their passive surface film, which is good for corrosion resistance. However, the high resistivity of the passive film increases interfacial contact resistance between the bipolar plates and the electrodes. Stainless steels thermal spray coated with a mixture of tungsten carbide and stainless steel powders showed that the coated layer safely combined with the matrix but they suffered many internal defects including voids and cracks. Many cracks were formed in the coated layer and the interface of the matrix and the coated layer during the rolling process. The coated and rolled stainless steels showed lower interfacial contact resistance and corrosion resistance than bare stainless steel because of low resistivity of tungsten carbide and numerous defects, which caused crevice corrosion, in the coated layer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.931-934
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• 2002

In recent year there have been several developments in lamp technology that promise savings in electrical power consumption and improved quality of the lighting space. Above all, the advantage of Electrodeless fluorescent lamp is the removal of internal electrodes and heating filaments that are a light-limiting factor of conventional fluorescent lamps. Therefore, the life of Electrodeless fluorescent lamps is substantially higher than that of conventional fluorescent lamps and last up to 100,000 hours. In this paper, the Electromagnetic emitting properties were presented by simulation software operated at 2.65MHz and some specific conditions.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1756-1758
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• 2001

Recently, ozone is utilized in various fields and its needs are expanding. In this paper, fluorescent discharge type ozonizer has been designed and manufactured. Ozone discharge and generation characteristics have been investigated in accordance with a sort of internal electrodes, output voltage of power supply. flow rate and discharge power. Air has been used as the supplied gas of the ozonizer.

• Journal of the Korean Ceramic Society
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• v.38 no.6
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• pp.499-505
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• 2001

The behaviour of ionic compound crystals under combined chemical and externally applied electrical potential gradients is discussed. Firstly, a systematic overview is given. Then a formal analysis follows. The transport equations of the ions and the electric defects predict that even with reversible electrodes demixing, and in particular decomposition of the compound will occur if the applied d.c. current density is sufficiently high. These predictions are illustrated by appropriate experiments. With the help of the solid solution (Me, Fe)O, where Fe-ions are the dilute species, we investigate experimentally the behaviour of a ternary ionic crystal under a d.c. electric current load. All the compounds were placed in a galvanic cell, and the internal reactions which then could be observed were driven by the electric field in this cell. In addition, we discuss the influence of the electric field on the classical solid state reaction AX+BX=ABX$_2$, if again the reaction couple is placed in a galvanic cell.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1992.11a
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• pp.128-131
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• 1992

In this paper, the skewness properties of partial discharge at interface layer in mica-epoxy composite material were investigated and studied on interface specimens which has internal electrodes. As a result, it has been confirmed that the interface exists as abnormal resin layer and the contact condition at the interface is depended upon the density of si lane aqueous solution. The Pulse frequency of discharge at abnormal interface has been shown a linear increasing with enlargement of discharge quantity according to rising of the applied voltage. Whereas, in case of normal interface, pulse frequency represented exponential increasing at the saturating point of discharge quantity. The aging model can be represented from the variable characteristics of skewness.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.2307-2308
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• 2008

We observed internal space charge behavior for two types of epoxy composites under dc electric fields to investigate the influence of water at high temperature. In the case of glass/epoxy specimen, homocharge is observed at water-treated specimen, and spatial oscillations become clearer in the water-treated specimens. Electric field in the vicinity of the electrodes shows the injection of homocharge. In aramid/epoxy specimens, heterocharge is observed at water-treated specimens, i.e. negative charge accumulates near the anode, while positive charge accumulates near the cathode. Electric field is enhanced just before each electrode. In order to further examine the mechanism of space charge formation, we have developed a new system that allows in situ space charge observation during ion migration tests at high temperature and high humidity. Using this in situ system.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.145-148
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• 1999

In this paper, multi gap type ozonizer(MGO) has been designed and manufactured. The ozonizer is equipped with three electrodes(central electrode of screw shape, internal electrode and external electrode) of cylinder shape. This paper describes the following two characteristics: $\circled1$ The characteristics of discharge with variation of output voltage of AC H.V source, flux of oxygen supplied gas and discharge voltage. $\circled2$ The characteristics of ozone generation by varying flux and discharge power.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.1090-1092
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• 1999

In this paper, multi discharge type ozonizer has been designed and manufactured. The of ozonizer is equipped with three electrodes(central electrode of screw shape, internal electrode and external electrode). This paper describes the following two characteristics: (1) The characteristics of discharge with variation of output voltage of AC H.V source, flow rate of oxygen supplied gas and discharge voltage. (2) The characteristics of ozone generation by varying flow rate and discharge power.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.129-130
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• 1998

In this paper, We designed the ECG-NIBP-$SpO_2$ patient monitor. This production can measure Electrocardiograph, Heart Rate, Noninvasive Blood Pressure, and Oxygen Saturation for Noninvasive Mehod and can display each information. These informations were implemented by the electrodes of ECG part, the cuff of NIBP module and the finger probe with light sensor of $SpO_2$ without injection of needle or catheter. In addition, We developed a new analysis algorithm and measurement technique for NIBP and $SpO_2$ to observe patient's conditions correctly.