• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.15 no.6
• /
• pp.231-238
• /
• 2015

In this paper, we have studied a sheet resistance property of N- and P-type thin films deposited on ITO glass by use of RF magnetron sputtering. The N-type samples which has the deposition condition of 150W RF power, shows the highest current value, and the samples deposited for 15 minutes shows a better Ohmic contact property. As the substrate temperature, RF power and deposition time are increased, the sheet resistance of the samples is increased, and the low sheet resistance sample shows a better I-V property. The P-type samples shows the highest current value by 150W RF power condition as similar as N-type samples. and the samples deposited for 20 minutes shows a better ohmic contact property. The sheet resistance of the both types samples is increased as increasing RF power and deposition time.

• Tribology and Lubricants
• /
• v.16 no.1
• /
• pp.9-14
• /
• 2000

It has been cleared in previous author's paper that the fatigue life before the pitting on the rolling contact surface with lubricant are influenced by the wear amount. In this study, the wear type has been clarified when wear amount is extremely large such as the case without lubricant. The test of rolling contact fatigue has been conducted under two different of herzian pressures and three different of slide ratios without lubricant. In addition, residual stress and half-value breadth using X-ray diffraction on worn surface have been measured as well as the wear amount. The results show that the pitting type wear by rolling contact fatigue has not been occurred when the wear amount is considerably large. Thus this type of wear has been deduced by the fatigue wear depending on delamination theory.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.10a
• /
• pp.556-559
• /
• 2004

This study was aimed to verify the acceptable contact force between power collector and 3rd rail type conductor rail for the Korean standardized rubber-tired AGT light rail vehicle. The power collector was designed and manufactured to satisfy the Korean standardized Specifications of the rubber-tired AGT light rail vehicle. Based on the dynamic behavior, contact force variation and interruption in the worst installation tolerance of the conductor rail, its initial contact force was set up. With rotary disk type equivalent test apparatus with circular conductor rail, the interruptions were measured. As the results, acceptable contact force was proposed to ensure power collection stability.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2003.10a
• /
• pp.175-178
• /
• 2003

Mechanical behavior of a fuel stack was studied by the orthotropic material model. The fuel stack is mainly composed of bipolar plate (BP), gasket, end plate, membrane electrolyte assembly (MEA), and gas diffusion layer (GDL). Each component is fastened with a suitable pressure. It is very important to maintain a suitable contact pressure of BP, because it affects the efficiency of the fuel cell. This study compared mechanical behavior of various fastening types of the fuel cell stack. Bar, band, and modified band fastening type are used. The band fastening type showed that it reduces total volume of the cell, but it does not improve the contact pressure distribution of each BP. The modified band fastening type was designed by considering the deformations of band fastening type, and it showed a good enhancement of contact pressure distribution.

• Journal of Astronomy and Space Sciences
• /
• v.17 no.2
• /
• pp.151-162
• /
• 2000

The general properties of the NCBs, divided into A and F types according to their spectral types, have been presented. The evolutionary status of the F type near-contact binaries are closer to that of the contact systems, i.e., W UMa type binaries, if it is assumed that the evolution of the NCBs is governed by the thermal relaxation oscillation theory. The mass-radius relation, mass-luminosity relation and H-R diagram of the NCBs provide that the A type NCBs suffer from more active mass transfer than F types. The components of the NCBs ar still in main-sequence like W UMa type stars and their two components lines parallel to the ZAMS.

• Korean Journal of Materials Research
• /
• v.26 no.8
• /
• pp.412-416
• /
• 2016

The electrical properties of Au/n-type Ge Schottky contacts with different contact areas were investigated using current-voltage (I-V) measurements. Analyses of the reverse bias current characteristics showed that the Poole-Frenkel effect became strong with decreasing contact area. The contribution of the perimeter current density to the total current density was found to increase with increasing reverse bias voltage. Fitting of the forward bias I-V characteristics by considering various transport models revealed that the tunneling current is dominant in the low forward bias region. The contributions of both the thermionic emission (TE) and the generation-recombination (GR) currents to the total current were similar regardless of the contact area, indicating that these currents mainly flow through the bulk region. In contrast, the contribution of the tunneling current to the total current increased with decreasing contact area. The largest $E_{00}$ value (related to tunneling probability) for the smallest contact area was associated with higher tunneling effect.

• The Bulletin of The Korean Astronomical Society
• /
• v.37 no.2
• /
• pp.143.1-143.1
• /
• 2012

We attempt to investigate the main reason of the asymmetrical light curves of contact and near-contact eclipsing binary base on the hypothesis that cool spot was produced on late type star while hot spot was produced from transferred material from their companion star hitting surface. We select 7 eclipsing binary systems which showed asymmetric light curves and mass transfer. Period variation and mass transfer rate were obtained from O-C diagram. Radial velocity curves and light curves of those 7 eclipsing binary system were adopted from available literature in order to obtain the absolute dimension. For four contact eclipsing binary system (AD Phe, EZ Hya, AG Vir and VW Boo), their component stars belonged to spectral type G to K was fitted by cool spot model. While the other two near-contact systems (RT Scl and V1010 Oph) and one contact system (SV Cen) was fitted by cool spot model. The densities of the materials are adopted from stellar model which calculate by stellar structure code. The calculated spot temperature turns out to agree with the photometric solution but there are no correlate between period variation rate and type of spot.

• ETRI Journal
• /
• v.32 no.5
• /
• pp.722-728
• /
• 2010

This paper presents the design and fabrication model of a touchpad based on a contact-resistance-type force sensor. The touchpad works as a touch input device, which can sense contact location and contact force simultaneously. The touchpad is 40 mm wide and 40 mm long. The touchpad is fabricated by using a simple screen printing technique. The contact location is evaluated by the calibration setup, which has a load cell and three-axis stages. The location error is approximately 4 mm with respect to x-axis and y-axis directions. The force response of the fabricated touchpad is obtained at three points by loading and unloading of the probe. The touchpad can detect loads from 0 N to 2 N. The touchpad shows a hysteresis error rate of about 11% and uniformity error rate of about 3%.

• Tribology and Lubricants
• /
• v.5 no.2
• /
• pp.60-67
• /
• 1989

For the life prediction and fatigue failure prevention of the constant velocity joint, the maximum equivalent stress and its location in depth from the contact area are essential. These values give the fundamental information to determine the depth of the surface hardening treatment at the contact area. Contact stresses are evaluated at the surface and subsurface of the ball groove of the Weiss type constant velocity joint. The maximum contact pressure and the maximum equivalent stress are obtained. The effects of various parameters such as the radius of ball groove, friction coefficient, and residual stress are studied. The maximum equivalent stress and the maximum contact pressure increase as the radius of the ball grove increases. The location of the maximum equivalent stress moves toward surface as the friction coefficient increases. It was also found that the maximum equivalent stress becomes minimum when the compressire residual stress is about 0.16 times of the maximum contact pressure.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 1999.11a
• /
• pp.80-80
• /
• 1999