• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.4
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• pp.149-155
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• 2010

This paper was carried out to estimate pollution levels of various insulators in tunnel and establish cleaning period in each tunnel section. We estimate pollution level that is attached to insulators in environmental pollution area, industrial area, salt damage area. These results that the pollution quantity and conductivity were increased by pollution accumulation period. However, the conductivity showed each other big difference in each tunnel. In particular, the conductivity showed big in environmental pollution(tunnel A) and salt damage(tunnel C) area, It is considered to prevent accident that manage establishing periodic state of cleaning plan. Also, the Grease that spread on the insulator surface in existing is considered that it can prevent accident for long-term by restrain use.

• Journal of the Korean Institute of Telematics and Electronics
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• v.15 no.3
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• pp.18-23
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• 1978

In order to improve the efficiency of Cu2-xS-CdS PN junction type solar cell, a method of reducing the series resiatance is considered. In the fabrication of the thin film of Cu2-xS, what has the largest value of conductivity is fabricated at 250 $^{\circ}C$. The thin film of CdS which has beer fabricated at the temperature 250-30$0^{\circ}C$ of the substrate and 800-85$0^{\circ}C$ of evaporating material has the largest value of conductivity and also fairly good photoelectric characteristics. Therefore, the evaporated thin aim type CdS solar cell has been fabricated at the temperature 25$0^{\circ}C$ of the substrate and 800-85$0^{\circ}C$ of the evaporating material, and its efficiency is measured to he 6%.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.10
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• pp.2059-2064
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• 2011

The DGPS systems that is a GPS augmentation system were installed for ocean- and land-service. The ocean-based reference station of 11 site and the land-based reference station of 6 sites are operating for ocean- and land-service. Although the land-based reference stations provide the output power of 500W, the service shadow regions are occurred due to mountain lands and building area. In this paper, the service coverages for land-based reference stations are analyzed in conditions of output power enhancements of reference station. The service shadow areas are deduced from service coverages of land-based reference stations and ocean-based reference stations. The medium frequency-band wave propagation models are considered as DGPS wave propagation model. The service coverages are analyzed by considering the compensated ground surface-conductivity.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.6
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• pp.71-76
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• 2007

This paper describes a risk assessment of electric shock based on a experiment which demonstrates a submerged commercial power source. For the experiment a water tank was made and an outlet was installed on an interior wall. After filling the tank with a conductive water solution, the electric potential was measured with the distance, the direction from the power source, the conductivity and the level of the water solution. As a result, the potential distribution due to the outlet energized and exposed to the water solution depends on the distance from the submerged power source, however, the direction from the power source, the conductivity and the level of the water solution seemed to scarcely affected on the electrical shock risk.

• Korean Journal of Optics and Photonics
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• v.25 no.5
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• pp.279-285
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• 2014

We propose an electrically controllable terahertz wave modulator based on a metamaterial and vanadium dioxide ($VO_2$) thin film. A square loop shape is designed to play the roles of both a resonating metamaterial and a heater to electrically control the conductivity of $VO_2$. The transmission characteristics of the modulator were controlled by voltage. The transmission coefficient of the modulator was stably changed from 0.27 to 0.80 at 470 GHz according to the conductivity values of $VO_2$.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.1
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• pp.1-6
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• 2008

A wearable T-matching dipole UHF RFID tag antenna has been designed using conductive electro-thread. The conductivity of the electro-thread has been measured depending on the number of twisted thread. The measured conductivity has been used for simulation to have accurate simulation results. The flexible electro-thread or fabric has been used for fabricating the antenna instead of using copper tape since the electro-thread is more flexible and wearable than copper tape. The return loss and reading range of the fabricated electro-thread UHF RFID tag antennas have been tested. The reading range is approximately 2.4 m.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.265-265
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• 2009

전기이중층 커패시터 전극으로 사용하는 활성탄에 도전제로서 CNT와 super-p의 함량에 따른 이중층 커패시터의 특성을 연구하였다. CNT 함량이 4wt%까지는 도전제로서 CNT 함량이 증가할 수록 용량이 감소하는 반면 6wt%이상에서는 CNT 함량이 증가할 수록 단위 체적당 정전용량이 증가하였다. 충, 방전 특성과 직류 저항도 정전용량의 경향과 유사함을 보이고 있으며 이와 같은 결과는 비표면적이나 도전율에 의한 결과 보다는 분산성에 의한 결과로 예상된다. Super-p 10.5wt%, CNT 6.0wt%에서 단위 체적당 정전용량은 $22g/cm^3$, 직류저항 6.1[$\Omega$]의 전기이중층 커패시터 특성을 얻을 수 있었다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.3
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• pp.89-98
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• 1998

Some analytic results for a solenoid eddy current coil to test nondestructive conducting materials are described in this paper. Normalized impedance of solenoid coil encircling cylindrical conducting tubes or tow-conductor rods is analyzed. Electrical and magnetic properties such as conductivity, permeability and exciting frequency as well as the geometric ones of fill factor or radius ratio of the conductor are also considered. Impedance characteristics of the models obtained by numerical analysis are examined. Validation of the model is carried out using several samples of non-ferromagnetic conducting tubes and 2-conductor rods.

• Composites Research
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• v.35 no.2
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• pp.69-74
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• 2022

In this study, the conductive paste used in a wide range such as wiring in the electronic packaging field, the automobile industry, and electronic products is manufactured under various process conditions due to the simplicity of the process, and then the thermal, mechanical, and electrical characteristics are analyzed and simulation studies are conducted to optimize the process. to establish the conditions of the conductive paste manufacturing process. First, a conductive paste was prepared by setting various types of binder resin, an essential component of the conductive paste, and characteristics such as thermal conductivity, tensile strength, and elongation were analyzed. Among the binder resins, the conductive paste applied with a flexible epoxy material had the best physical properties, and a simulation study was conducted based on the physical property data base of the conductive face. As a result of the simulation, the best physical properties were exhibited when the Ag flake volume fraction was 60%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4835-4841
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• 2015

The effect of particle size and compaction pressure on the thermoelectric properties of n-type $FeSi_2$ was investigated. The starting powders with various particle size were pressed into a compact (compaction pressure; $70{\sim}220kg/cm^2$). The compact specimens were sintered at 1473 K for 7 h and annealed at 1103 K for 100 h under Ar atmosphere to transform to the semiconducting ${\beta}$-phase. The microstructure and phases of the specimens were observed by SEM, XRD and EDS. The electrical conductivity and Seebeck coefficient were measured simultaneously for the same specimen at r.t.~1023 K in Ar atmosphere. The electrical conductivity increased with decreasing particle size and hence the increases of relative density of the sintered body and the amount of residual metallic phase ${\varepsilon}$-FeSi due to a increase of the electrical conductivity. The Seebeck coefficient exhibited the maximum value at about 700~800 K and decreased with decreasing particle size. This must be due to a increase of residual metallic phase ${\varepsilon}$-FeSi. On the other hand, the change of compaction pressure appeared to have little effect on the thermoelectric properties. Consequently, the power factor would be affected more by particle size than compaction pressure.