• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1992.11a
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• pp.110-113
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• 1992

This paper presents the results on experiments of relative dielectric constant dielectric loss, conductivity change and breakdown voltage of the L.D.P.E. mixed with Dodecyl Alcohol. The frequency range is 0.1 - 20 MHz and temperature, 20 - 80 $^{\circ}C$. Dielectric properties were similar to those of nonpolar polymers. Until $60^{\circ}C$ the conductivity value of compound was decreased with temperature increasment. And, its breakdown voltage was measured higher, about 3-4KV, than that of the pure L.D.P.E.. Also the amount of remnants of DA in the compounds were considered.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.10
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• pp.659-664
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• 2016

Thermal and electrical conductivities of the natural, artificial, and expandable graphites were analyzed after treatment in NaOH aqueous solution. In order to investigate the elimination of the oxidized groups and impurities on the graphite surfaces after NaOH treatment, the graphite samples were structurally characterized by using XRD, XPS, Raman, FE-SEM. The thermal and electrical conductivities of the graphite samples were significantly improved after NaOH treatment. These results were caused by the structural rehabiliation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.518-521
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• 2003

A new measurement system was developed by fault diagnosis system for traction motor using current signal analysis. The motor current signature analysis method is used for traction motor fault diagnosis. The diagnosis system program is constructed by artificial neural networks algorithm, those results from the program are used to train neural networks. The trained neural networks have the ability to compute adaptive results for non-trained inputs, and to calculate very fast due to original parallel structure of neural networks with high accuracy within destined tolerance. This system suggested that available test for checking, the probable extent of aging, and the rate of which aging is taking place.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.517-520
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• 2001

The optical properties of $TiO_2$ thin films dispersed in epoxy film, which were prepared with bis-(4, 4'-P-toluenesulfonylacidic isoproplyidene) cycolhexadiol(BTSPC) and UVI 6990 in dry sol-gel process, were investigated. In the case of irradiating UV light on $TiO_2$ thin films, how many nanopartlcles of $TiO_2$ are dispersed in epoxy film was investigated by AFM. The absorption peak of the films was showed at 360nm. Squarylium dye was dispersed in $TiO_2$-epoxy film. Photodegration concerned with amount of dye and time of UV light irradiation was investigated. UV light irradiation on the film occurred dramatical photodegration.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.378-381
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• 2001

The electron drift mobility of poly(4,4'-cyclohexylidenediphenyl carbonate) (PC-Z) doped with 3,5-dimethy-3,5-di-t-butylstilbenequinone(MBSQ), 3,5,3,5-tetra-t-butyl stilbenequinone(TBSQ) and 3,5,3,5-tetra-methyl stilbenequinone(TMSQ) was measured by the time-of-flight technique. The electric field and temperature dependences of the electron drift mobility were discussed with Poole-Frenkel, Arrhenius formulations and non-Arrhenius type of temperature dependence. It was assumed that the hopping sites were Gaussian distribution. Mobility and activation energy of MBSQ were increased with increasing dopant. However, mobilities and activation energy of TBSQ and TMSQ were increased and decreased, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.406-409
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• 2001

The conductivity properties and synthesis of $LaNiO_{3}$ ceramics from $La_{1+\delta}NiO_{3}(\delta=-0.06,0,0.06)$ were investigated. A single perovskite phase was realized at $800^{\circ}C$. $La_{2}NiO_{4}$ and other unexpected oxide were observed at $1000^{\circ}C$. The Microstructure was showed clearly that it is a low density porous material. $LaNiO_3$ ceramic showed a metallic conductivity. The conductivity of La rich samples had a higher value than the La poor samples.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.312-315
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• 2001

Recently organic electroluminescent devices have been intensively investigated for using in full-color flat-panel display. Since the quantum efficiency of electrophosphorescent device decrease rapidly as the luminance increase, it is desirable to operate the electrophosphorescent display with active matrix rather than passive matrix. Here we report the study of driving electrophosphorescent diode with all organic thin film transistor(OTFT). The structure of electrophosphorescent diode is ITO/TPD/BCP:Ir(ppy)$_3$/BCP/Alq$_3$/Li:Al/Al. In OTFT. polymer is used as an insulator and pentacene as an active layer. Detailed performance of the integrated device will be discussed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.05a
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• pp.6.2-8
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• 1996

The NO$_2$ GAS-detection characteristic of CuTBT (Copper-tetra-tert-butylphtha1ocyanine) LB films were investigated through a study of current-voltage (I-V) characteristics with a variation of number N of interdigital electrodes (N=1∼25). A concentration of 200ppm NO$_2$ gas was used. It was found that a conductance G increases monotonically as the number of interdigital electrode increases, and a sensitivity $\Delta$G ($\Delta$G=G$\_$gas//G$\_$air/) is at least higher than 50 and stable. As far as a sensitivity is concerned, the sensitivity when N=26 is greater than that when N=1 by 70 or so. It indicates that the number of interdigital electrodes affects the currents, sensitivity and stability.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1988.05a
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• pp.17-19
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• 1988

$YBa_2Cu_3O_{7-x}$ oxide superconductors were fabricated by the hot isostatic pressing (HIP). It was shown that their structures were orthorombic and constited of a single (123) phase. While as-sintered compacts had many pores, they were remarkably reduced by Hiping. The on-set and off set temperature of (123) compound sintered at $950^{\circ}C$ in oxygen and hiping at $880^{\circ}C$ were the highest and it showed 0 resistance at $90^{\circ}K$. The critical current density ($J_c$) of the above superconductor was $27A/cm^2$ and it also showed a number of twin structures, which are typical of high $T_c$ superconductor. It seemed that the low current density may be due to the many pores of starting-sintered compacts.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.204-205
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• 2005

[ $(Na_{0.5},\;K_{0.5})NbO_3$ ] ceramics were studied as lead free Piezoelectric materials. The addition of CdO were enhanced the sinterability of the NKN ceramics. The $(Na_{0.5},\;K_{0.47}Cd_{0.02})NbO_3$ ceramics show that electromachanical coupling factor($k_p$) is 0.34and mechanical quality factor($O_m$) is 120.