• Journal of the Korean Society for Precision Engineering
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• v.21 no.2
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• pp.21-26
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• 2004

The formed tool is used to machine the geometrical shape of bearing rubber seal efficiently. The bearing rubber seal has complex geometry for the complicated geometrical shape to prevent leakage of lubricant oil and influx of the dust effectively. Because it is difficult to machine the unique shape exactly by the conventional tool, the formed tool is used in machining a rubber seal die. In this paper, It is performed to investigate machining characteristic of the formed tool； cutting edge wear, cutting force, and surface quality. Also, an efficient precision machining condition is proposed, and the inspection results of rubber seal with CAI are discussed.

• Korean Journal of Materials Research
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• v.14 no.7
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• pp.516-521
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• 2004

We applied a deuterium plasma treatment to the surface of polycrystalline silicon films using PECVD and observed the change with AFM, XRD, ET-IR, and SIMS measurement. A bias temperature stressing (BTS) test was carried out to evaluate the reliability of the thin-film transistors (TFT). TFTs with channel lengths as small as 2 ${\mu}m$ were electrically stressed fer up to 1000 sec at room temperature. From the parameter variation such as s-factor, leakage current and on/off ratio, we suggest that the deuterium plasma treatment suppress the hot carrier effect and improve the stability of TFTs.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2130-2131
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• 2011

Electric fire breaks out by various causes such as electric short, overload(over current), leakage current, poor contact, static electricity, insulation deterioration, partial disconnection and etc. In this paper, we studied analysis technique for scientific and systematic judgment for distinction of electricity fire existence and nonexistence, and described about electricity fire cause analysis process for collecting physical evidences. We handled external form analysis, Substance extension analysis, X-ray transmission analysis, cross-section analysis, thermal analysis, chemical structure analysis, surface structure analysis, component analysis, electrical properties analysis, and circuit analysis by analysis technique for electricity fire cause judgment. We expect that analysis technic elevation and correct cause of fire analysis of scene of a fire investigators and analysts through this paper which see help.

• Journal of the Korean Society of Safety
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• v.14 no.2
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• pp.109-115
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• 1999

The release of gas from the LPG storage tank by the rupture or leakage can occure explosion and this causes serious damage to people and structures. In this study, the explosion effect and damaging distance were measured for the LPG cloud explosion to perform the quantitative risk assessment for the PSM, and the effective parameters on the explosion were found. The gas dispersion and mass contaminant in the explosion limits were calculated by using DEGADIS, and it was converted to TNT equivalency and damaging distance. As a result, the wind speed was the most effective parameter on the diffusion rate and TNT equivalency, and the damaging distance were increased with decrease of wind speed and surface roughness.

• Journal of Electrical Engineering and Technology
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• v.6 no.6
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• pp.836-841
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• 2011

Plasma polymerized methyl methacrylate (ppMMA) thin films were deposited by plasma polymerization technique with different plasma powers and subsequently thermally treated at temperatures of 60 to $150^{\circ}C$. To find a better ppMMA preparation technique for application to organic thin film transistor (OTFT) as dielectric layer, the chemical composition, surface morphology, and electrical properties of ppMMA were investigated. The effect of ppMMA thin-film preparation conditions on the resulting thin film properties were discussed, specifically O-H site content in the pMMA, dielectric constant, leakage current density, and hysteresis.

• 한국가스학회:학술대회논문집
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• 2007.04a
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• pp.18-23
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• 2007

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.717-720
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• 2001

Ferroelectric lead ziroconate titanate (PZT) thin film were fabricated on the different bottom electrodes. Both Ru and Ru/RuO$_2$bottom electrodes were deposited by RF-magnetron sputteirng method. The structure phase and surface morphology of the PZT thin film were largely affected by the bottom electrode. It was observerd that used of Ru/RuO$_2$double electrode reduced leakage current and better ferroelectric properties compare with RuO$_2$bottom electrode. From these results, Ru/RuO$_2$hybride bottom electrode is thought to be the available structure for the bottom electrode.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.194-197
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• 2002

Applying dual layer insulator on plastic substrates improved electrical characteristics of organic thin film transistor(TFT). A high-quality silicon dioxide(SiO$_2$) suitable for a insulator was deposited on plastic substrates by e-beam evaporation at 110$^{\circ}C$. The insulator film which was treated by N$_2$ annealing at 150$^{\circ}C$ showed excellent I-V, C-V characteristics. The dual layer insulator structure of polyimide-SiO$_2$ improved the roughness of SiO$_2$ surface and showed very low leakage current. In addition, the flat band voltage has been reduced from -2.5V to about 0.5V.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.378-379
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• 2008

Recently, composite hollow bushings have been increasingly employed mainly from the various characteristics. Composite bushings are superior to porcelain bushings in several respects, including lighter weight, better anti-pollution and anti-explosion properties, and easer manufacturing. Filament wound GRP tubes which have various winding angle were manufactured by using a filament winding machine. This paper will show some design issues and winding condition for composite bushing. And, results show that the winding condition of composite GRP tubes can be used to improved their bending strength and pressure, For bending and pressure tested, tubes with the hybrid winding pattern show higher strength than those of unit winding pattern. Also, the influence of absorption was evaluated through such as measurement of the dye penetration test and water diffusion test, also aspects of surface state using scanning electron microscopy.

• International Journal of Fluid Machinery and Systems
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• v.6 no.1
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• pp.18-24
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• 2013

In order to apply the design method of diagonal flow fan based on axial flow design to the design of radial-outflow type diagonal flow fan which has lower specific speed of 600-700 [$min^{-1}$, $m^3/min$, m], radial-outflow type diagonal flow fan which specific speed was 670 [$min^{-1}$, $m^3/min$, m] was designed by a quasi three-dimensional design method. Experimental investigations were conducted by fan characteristics test, flow surveys by a five-hole probe and a hot wire probe. Fan characteristics test agreed well with the design values. In the flow survey at rotor outlet, the characteristic region was observed. Two flow phenomena are considered as the cause of the characteristic region, one is tip leakage vortex near rotor tip and another is pressure surface separation on the rotor blade.