• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.254-257
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• 2002

The purposes of this research are to identify the source and to analyze the pathway of nitrate contamination in "cultural village", Jeungpyeong. In order to examine recharge processes and flow pattern that closely related to the influent of nitrate contaminant, the flow field was simulated and the oxygen and hydrogen stable isotopes were analyzed. The nitrogen isotope was used to delineate contaminant sources. The shallow groundwater was mainly composed of precipitation, but leakage of domestic water and sewage contributed to the recharge. Nitrate contaminants were possibly from the leakage of sewage and animal waste. The nitrate concentration decreased due to dilution by low concentration water.ion water.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.221-224
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• 2002

To demonstrate prevention of the leachate leakage out of the landfill with creating inward hydraulic gradient, a tracer test and continuous waterlevel monitoring at the Inside and outside of the barrier wall of a costal landfill were peformed. When the tracers were injected into the well outside of the vertical wall system with high water level, then they were detected at the well inside of the system with low water level. Furthermore the lowered water level at the inside of the landfill than that at the outside prevented leachate leakage out of the landfill. This study reports results of the tracer test and waterlevel monitoring.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.178-182
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• 1991

Contact resistance and contact leakage current of the $Al/TiSi_2/Si$ system are investigated for $N^+\;and\;P^+$ junctions. Titanium disilicide is one of the most common silicides because of its thermal stability, ability, to form selective formation and low resistivity. In this paper, the effect of RTA temperature and Junction implant dose are characterized. The $TiSi_2$ contact resistance to $N^+$ silicon is lower than that of Al to $N^+$ silicon, but $TiSi_2$ of contact resistance to $P^+$ silicon is higher than that of Al to $P^+$ silicon. The $TiSi_2$ of contact leakage current to $N^+\;and\;P^+$ silicon is similar to that of Al contact.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1111-1112
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• 2011

This paper investigated application of fractional-slot concentrated-winding axial flux permanent magnet machines for wind turbines. Design criteria of cogging torque and voltage regulation was firstly proposed for this kind of application. Fractional winding has small cogging torque which is highlight for wind turbines, but slot leakage inductance would increase voltage regulation, which is an important performance index of generators. By varying slot opening, cogging torque and slot leakage inductance could be adjusted. In this paper, cogging torque and inductances were calculated by both analytical and finite element methods. Voltage regulation was studied by two-axis model under unity-power-factor load and verified by transient finite element analysis.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.172-172
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• 2003

It has been known that Pd-MILC shows much faster and lower temperature crystallization than Ni-MILC but it can not be put into practice due to the quality issue of thus fabricated poly crystals. In this study, addition of Pd into Ni-MILC has been attempted in order to take advantages of the Pd-MILC without sacrificing of the Ni-MILC TFTs. It turns out that when 5% of Pd has been added to Ni for MILC, MILC growth rate increases two - three times faster than pure Ni-MILC. The MILC growth rate shows monotonic increase with increase the amount of Pd in Ni up to 50%. Even when small amount of Pd was added to Ni like 5%, crystallization phenomenon already follows the way of Pd-MILC. The Poly-W thus fabricated shows lower leakage current than pure Ni-MILC TFT without losing any amount of on-current This fact is very important in low temperature poly-TFTs because MILC-TFTs, especially suffer from the relatively high leakage current

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.12
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• pp.48-53
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• 2011

Polymer thin films were prepared by capacitively coupled plasma polymerization process for application of gate insulator. The polymer thin films revealed to form polymer layers with original properties of the monomer. Among the plasma polymer thin films, the styrene polymer having large number of phenyl sites revealed higher dielectric constant of k=3.7 than that of conventional polymer. The plasma polymerized styrene thin film revealed no hysteresis characteristics and low leakage current density of $1{\times}10^{-8}[Acm^{-2}]$ at field strength of $1[MVcm^{-1}]$, which measured by I-V and C-V measurements using MIM and MIS devices.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.291-294
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• 2007

This paper preserts the characteristics of leakage currents flowing through 18 kV zinc oxide (ZnO) surge arrester under the mixed DC and AC voltages. The I-V curves of ZnO surge arrester were measured as a function of the voltage ratio K The I-V curves under the mixed DC and AC voltages lay between the pure DC and AC characteristics, and the cross-over phenomenon in I-V curves was observed at the low current region As a result, the increase of DC component to mixed voltages causes the increase of resistive component of total leakage current th ZnO surge arrester.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.581-584
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• 2000

This paper describes the effect of lightning impulse current on ZnO varistors(390 V, 6.5 kA) used in low-voltage AC mains as a protective device against transient overvoltages. A lightning impulse current standardized in IEC 61000-4-5 is applied to the varistors, and the energy applied to the varistor at each time is about 12 J. In the experiment, various Parameters such as leakage current, reference voltage are measured with the number of applied impulse current. Also, micro-structure changes of the varistors after applying the lightning impulse current of 200 times are compared. The electrical characteristics of the varistors are degraded by overtime impulse current, showing increase in leakage current and decrease in reference voltage.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.8
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• pp.365-370
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• 2001

We have proposed and fabricated a new poly-Si TFT employing air-cavities at the edges of gate oxide in order to reduce the vertical electric field induced near the drain due to low dielectric constant of air. Air-cavity has been successfully fabricated by employing the wet etching of gate oxide and APCVD (Atmospheric pressure chemical vapor deposition) oxide deposition. Our experimental results show that the leakage current of the proposed TFT is considerably reduced by the factor of 10 and threshold voltage shift under high gate bias is also reduced because the carrier injection into gate insulator over the drain depletion region is suppressed.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.866-868
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• 1998

Room temperature vulcanizing(RTV)silicone rubber has been widely used to coat porcelain insulators to render water repellency to prevent formation of water filming on the surface and thus to suppress the leakage current and consequent flashover. However, the electrical property and its hydrophobicity of RTV silicone rubber coating under outdoor conditions may be influenced by many environmental factors. In this study various treatments, such as salt-fog, salt water immerging and UV irradiation were applied to samples for investigation the change of the electrical property and hydrophobicity. As a result the leakage current increased and contact angle decreased as the degradation time longer. But the degraded RTV silicone rubber has recovered its hydrophobicity during the drying time in ambient condition because LMW(Low Molecular Weight)silicone fluid diffused from the bulk to the surface.