• Progress in Superconductivity and Cryogenics
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• v.17 no.3
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• pp.37-40
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• 2015

Recently, the electrical insulation design for electrical apparatuses is important to cope with the tendency of high voltage. The degradation characteristics of a superconducting coil due to an electrical breakdown should be considered to design a high voltage superconducting coil. In this paper, the degradation characteristics of 2G high temperature superconducting (HTS) wires are studied with respect to electrical breakdown tests. To analyze the dependency of the degradation characteristics of 2G HTS wires, the electrical breakdown tests are performed with AC(alternating current) and DC(direct current) voltage. All tests are performed by applying various magnitudes of AC and DC breakdown voltages. To verify the degradation characteristics of 2G HTS wires, the tests are performed with various 2G HTS wires with respect to stabilizer materials. The degradation characteristics of 2G HTS wires, such as Ic(critical current) and index number are measured by performing electrical breakdown tests. It is found that the characteristics such as Ic and index number can be degraded by an electrical breakdown. Moreover, it is concluded that the degradation characteristics of 2G HTS wires are affected by the stabilizer material and applied voltages. The cross-sectional view of 2G HTS wires is observed by using a scanning electron microscope (SEM). As results, it is found that the degradation characteristics of 2G HTS wires are concerned with hardness and electrical conductivity of stabilizer layers.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.28-31
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• 2003

We have investigated the electrical characteristics of the organic light emitting diodes (OLEDs) using the numerical device simulation. The current-voltage characteristics, the charge carrier concentrations, and the recombination rate profiles are presented. The simulation results of the effects of the various device parameters on the device characteristics are discussed.

• Progress in Superconductivity and Cryogenics
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• v.17 no.1
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• pp.48-52
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• 2015

The electrical insulation design for a superconducting coil system is important for developing high voltage superconducting apparatuses. Also, the degraded characteristics of superconducting tapes due to an electrical breakdown should be considered for superconducting coils design. In this study, the degradation characteristics of 2G high temperature superconducting (HTS) tapes were studied with respect to electrical breakdown tests. The degradation tests of 2G HTS tapes were performed with various stabilizer materials. The degradation characteristics of 2G HTS tapes such as critical current(Ic) and index number were observed by performing electrical breakdown tests. It was found that the characteristics such as Ic and index number can be degraded by an electrical breakdown. Moreover, it was concluded that the degradation characteristics of 2G HTS tapes were affected by a stabilizer material and applied breakdown voltage. The cross sectional view of 2G HTS tapes was observed by using a scanning electron microscope (SEM). As results, it is found that the degradation characteristics of 2G HTS tapes are concerned with hardness and electrical resistivity of stabilizer layers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.235-238
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• 2003

Thermo-plastic has generally bad electrical characteristics at high temperature comparing to thermoset-plastics when the plastic apply to electrical power apparatus as an electrical insulator. To solve the problem, we study engineering plastics such as Polyamide and Polyphthalamide as a base resin. And filler of the engineering plastics is glass fiber. Electrical characteristics studied are permittivity, loss factor and breakdown strength according to temperature and frequency of measuring signal. Electrical characteristics of Polyphthalamide has good temperature and frequency dependency comparing to those of Polyamide.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1213-1215
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• 1997

In order to investigate the electrical characteristics due to the BTA(Benzotriazole) additive in the transformer, the electrical characteristics of the transformer oils contained benzotriazole as an anti-static agent for streaming electrification is studied by measuring the electric conduction. As a result of the electrical conduction characteristics, it is confirmed that the conduction current of virgin specimen is more higher than that of specimen contained the BT A 10[ppm] over 35[$^{\circ}C$], but that of specimen contained the BT A 10[ppm] over 50[$^{\circ}C$] is increased.

• KIEE International Transactions on Electrophysics and Applications
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• v.2C no.6
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• pp.321-326
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• 2002

This paper describes the mechanical and electrical characteristics of insulating paper impregnated with diluted varnish(W-128), according to Korean Standards. The varnish was diluted with a solvent of 6 different wt%. Kraft paper and Nomex paper were impregnated with the diluted varnish in a vacuum condition, and then completely dried. As the mechanical characteristics, the thickness of the completely dried varnish, the drying time and the tensile strength of the specimens were measured, and as the electrical characteristics, the permittivity, the tan $\delta$ and the specific resistance were evaluated as well.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.1
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• pp.6-11
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• 2005

In this paper, two types of vertical SIT(Static Induction Transistor) structures are proposed to improve their electrical characteristics including the blocking voltage. Besides, the two dimensional numerical simulations were carried out using ISE-TCAD to verify the validity of the device and examine the electrical characteristics. First, a trench gate region oxide power SIT device is proposed to improve forward blocking characteristics. Second, a trench gate-source region power SIT device is proposed to obtain more higher forward blocking voltage and forward blocking characteristics at the same size. The two proposed devices have superior electrical characteristics when compared to conventional device. In the proposed trench gate oxide power SIT, the forward blocking voltage is considerably improved by using the vertical trench oxide and the forward blocking voltage is 1.5 times better than that of the conventional vertical power SIT. In the proposed trench gate-source oxide power SIT, it has considerable improvement in forward blocking characteristics which shows 1500V forward blocking voltage at -10V of the gate voltage. Consequently, the proposed trench oxide power SIT has the superior stability and electrical characteristics than the conventional power SIT.

• Safety and Health at Work
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• v.11 no.4
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• pp.405-417
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• 2020

Background: Electrical socket outlets are used continuously until a failure occurs because they have no indication of manufacturing date or exchange specifications. For this reason, 659 electrical fires related to electrical socket outlets broke out in the Republic of Korea at 2018 only, an increase year on year. To reduce electrical fires from electrical socket outlets, it is necessary to perform an accelerated test and analyze the thermal, insulation resistance, and material properties of electrical socket outlets by installation years. Methods: Thermal characteristics were investigated by measured the temperature increase of electrical socket outlets classified according to year with variation of the current level. Insulation resistance characteristics was measured according to temperature for an electrical socket outlets by their years of use. Finally, to investigate the thermal and insulation resistance characteristics in relation to outlet aging, this study analyzed electrical socket outlets' conductor surface and content, insulator weight, and thermal deformation temperature. Results: Analysis showed, regarding the thermal characteristics, that electrical socket outlet temperature rose when the current value increased. Moreover, the longer the time that had elapsed since an accelerated test and installation, the higher the electrical socket outlet temperature was. With respect to the insulation resistance properties, the accelerated test (30 years) showed that insulation resistance decreased from 110 ℃. In relation to the installation year (30 years), insulation resistance decreased from 70 ℃, which is as much as 40 ℃ lower than the result found by the accelerated test. Regarding the material properties, the longer the elapsed time since installation, the rougher the surface of conductor contact point was, and cracks increased. Conclusion: The 30-year-old electrical socket outlet exceeded the allowable temperature which is 65 ℃ of the electrical contacts at 10 A, and the insulation resistance began to decrease at 70 ℃. It is necessary to manage electrical socket outlets that have been installed for a long time.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.7
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• pp.38-46
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• 1993

Based on the close correlation between the optoelectronic and electrical characteristics of laser diodes, this paper is to present an exact model for electrical characteristics of laser diodes with bulk active layers so that the optoelectronic characteristics may be estimated from the electrical Characteristics. Among the considered models, the most exact model is shown to be one which uses the Fermi-Dirac integral and the bimolecular recombination and takes into account the energy-gap shrinkage with the injected carrier density.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.1054-1056
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• 2001

This paper deals with underground transmission system of present and ZnO element of newly developed. in the characteristics of ZnO element of newly developed, an newly developed ZnO element compared with previous ZnO element that electrical characteristics and external characteristics. In result, characteristics of newly developed ZnO element is improved than previous one.