• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.21-25
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• 1999

In order to remove minority carries of the base region at changing signal in conventional bipolar logic circuit, we made transistor which is composed of NPN transistor shortened buried layer under the Base region, PNP transistor which is merged in base, epi layer and substrate. Also the Ring-Oscillator for measuring transmission time-delay per gate was designed as well. In the result, we get amplitude of logic voltage of 200mV, the minimum of transmission delay-time of 211nS, and the minimum of transmission delay-time per gate of 7.26ns in AC characteristic output of Ring-Oscillator connected Gate.

• Journal of the Semiconductor & Display Technology
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• v.14 no.4
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• pp.84-87
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• 2015

We have designed and fabricated two different RF-DC Converters called doubler for 5.8GHz Microwave Wireless Power Transmission. The doubler as RF-DC Converter makes the rectified voltage be doubled. We measured and compared voltages of the doublers with those of the previous full-wave rectifying RF-DC Converter. The doublers show rectified double voltages. However, the full-wave rectifying converter has a high efficiency due to the suppression of reflecting harmonics. The other fabricated doublers causes so many harmonics that they can't convert the low-power RF to the full DC. In this paper, we show that the different doublers doesn't double the rectifying voltages compared with those of the full-wave rectifying converter and give a reason about that.

• Journal of the Semiconductor & Display Technology
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• v.15 no.1
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• pp.33-35
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• 2016

This paper proposes a method utilizing image compression and transmission method for image segmentation in order to reduce the time required in the process of analyzing the image information that has in the image compression process. Many studies of existing with respect to the image segmentation are being studied as a way to split a lot of a particular part in the image. We divide full image into the N equal parts. And it is compressed using the field coding. This will reduce the time-consuming than using the conventional method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.52-56
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• 2001

Experiments of 2 type on insulating compounds accomplished to change PVC using in URD(Underground) power cable jacketing. one was DB(Dielectric Breakdown) test on the pure base resins and the others were WVT(Water Vapor Transmission) test on the compounds which contained C/B(Carbon Black), anti-oxidant to base resin. a kind of specimens made by pressing to resin of pellet or lump form was HDPE(High Density Polyethylene), MDPE(Medium Density Polyehylene), LDPE(Low Density Polyethylene), LLDPE(Linear Low Density Polyethylene), PVC(Polyvinyl Chloride). As a results of AC DB and WVT test, we saw that strength of Insulation was HDPE> LLDPE = MDP E> LDPE and WVT ratio was HDPE

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.458-459
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• 2007

This paper describes the characteristics of lightning impulse current of ZnO block for transmission line arrester with external gap. The ageing parameters of lightning arresters are impulse current, moisture ingress, temperature ageing and so on. Especially it is important to estimate the change of electrical characteristics by impulse current. Total energy applied to the ZnO arrester each time is $4/10{\mu}s$, 30kA and $2/20{\mu}s$, 10kA impulse current. Before and After the test, the residual voltage variation of varistors passed was below 5%. According to the test, it is thought that the ZnO arrester shows good stability with impulse current test.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.538-540
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• 2007

A detailed study on aged sleeves for old transmission lines was carried out to clarify the deterioration of sleeves and the condition of installation. A lot of removed aged sleeves from transmission lines were investigated. Many biased installed cases and corrosion of steel sleeve part were found. These defects can cause a serious accident such as blackout during operating. The detailed results were presented in the text.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.397-400
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• 2004

The design concept for 8kV light triggering thyristor(LTT) with integrated BOD was discussed here in detail. The trade-off between light triggering input source againsthigh dV/dt limitation has been treated via grooved P-base for gate design. The main application point used for high voltage DC transmission(HVDC) was represented.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.558-559
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• 2005

Recently, polymer insulators that are used for high voltage applications have some advantages such as light weight, small size, vandalism resistance, hydrophobicity and easy making process. During outdoor service of polymer insulators, the surface of the insulating material is frequently subjected to moisture and contamination that lead to dry band arcing. Their tracking resistance, erosion resistance, end sealing and shed design are very important because dry band arcing causes degradation of polymer surface. In this paper, the tracking property of polymer suspension insulator for power transmission is investigated with CEA tracking wheel test. The diagnosis of insulator sample in tracking test has been analyzed by leakage current, STRI Guide, SEM, FTIR and thermal image.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.63-64
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• 2006

Recently, researches for high-speed optical devices have been increased to provide mass data transmission and high-speed optical communication. Optical modulator in the transmission link is one of the crucial devices in total optical network system and it can affect a great effect to the whole transmission properties. In this paper, traveling wave electro-absorption modulator (TWEAM) is examined to ensure high efficiency in the RF range and wide bandwidth. In addition, the temperature-dependence electrical characteristics of TWEAM is investigated. Temperature dependent property variations were characterized using I-V and C-V measurement.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.1
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• pp.61-64
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• 2010

Footing Resistance of a 154 kV transmission towers in korea is commonly required to be less than 15 ohm to avoid lightning back-flashover accident. The periodic measurement of Footing Resistance is important to verify that the grounding performance of the towers has been maintained good. Towers are electrically connected in parallel with overhead grounding wire, therefore footing resistance of each tower will be measured after disconnecting the overhead ground wires from the towers. however, In this paper, three direct measurement methods of footing resistance are presented. There are very useful methods without disconnecting overhead ground wires from the tower under measurement. They are compared in KEPCO 154 kV transmission towers. The experimental results describe performances of them.