• Proceedings of the IEEK Conference
• /
• 1998.10a
• /
• pp.541-544
• /
• 1998

A SiGe p-channel MESFET using $\delta-doped$ layers is designed and the considerable enhancement of the current driving capability of the device is observed from the result of simulation. The channel consists of double $\delta-doped$ layers separated by a low-doped spacer which consists of Si and SiGe. A quantum well is formed in the valence band of the Si/SiGe heterojunction and much more holes are accumulated in the SiGe spacer than those in the Si spacer. The saturation current is enhanced by the contribution of the holes inthe spacer. Among the design parameters that affect the performance of the device, the thickness of the SiGe layer and the Ge composition are studied. The thickness of $0~300\AA$ and the Ge composition of 0~30% are investigated, and the saturation current is observed to be increased by 45% compared with a double $\delta-doped$ Si p-channel MESFET.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.21 no.4
• /
• pp.128-134
• /
• 2013

High bending collapse performance (maximum resistance force and mean resistance force) of body center pillar is an important design target for vehicle safety against side impact. In this study, effect of the upper section shape and the thickness of outer reinforcement on bending collapse performance was investigated for the center pillar of a large passenger car. First, through bending collapse analyses using simple models with uniform section, an optimized center pillar upper section was chosen. Next, bending collapse performance for various models of the actual center pillar with changing the thickness of outer reinforcement were analyzed. The finally designed model showed distinctive enhancement in bending collapse performance nearly without weight increase.

• Journal of Ocean Engineering and Technology
• /
• v.17 no.6
• /
• pp.77-82
• /
• 2003

The absorption of water into an anti-corrosive organic coating, such as alkyd and urethane resin coating, was investigated, using a quartz crystal microbalance (QCM). Anticorrosive properties of the coatings were also measured, by means of electrochemical impedance spectroscopy (EIS). The overall absorption of water in the coating is determined by the chemical nature of resin, and decreases with increasing thickness. The enhancement of anti-corrosive performance, through increase of coating thickness, was more remarkable in the case of the coating that hadlower equilibrium water absorption. The absorption kinetics curves were Fickian in nature. The EIS analysis confirmed that the resin, having lower equilibrium water absorption, shows higher anti-corrosive performan.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.113-116
• /
• 2008

The active layer thickness and curing condition dependent performance of an organic thin film transistor (OTFT) with inkjetted organic semiconductor (OSC) layer is studied The best performance of the OTFT was found when the thickness of ose was ~120 nm cured at $60^{\circ}C$. The performance enhancement of the OTFT with inkjetted OSC layer was discussed by comparing the OTFT with spin-coated ose layer.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.184.1-184.1
• /
• 2014

Nanostructures on Graphene surface receive highly attraction for many applications ranging from sensing technologies to molecular electronics. Recently J. Jasuja et al. reported the electrical property tailoring and Raman enhancement by the implantation and growth of dendritic gold nanostructures on graphene derivatives [ACSNANO, 3, 2358, 2013] Here, we introduced Si vapor on the graphen to induce the nanostructure. The surface property change of graphene by controlling the amount of Si and the thickness of graphene were investigated using high resolution photoemission spectroscopy (HRPES), and atomic force microscopy (AFM). The Si nanostructures on graphene show the thickness dependency of graphene, and the size of Si nano-structure reached to 7 nm and 15 nm on the mono and the multilayered graphene after $30{\AA}$ Si evaporation.

• Journal of the Korean institute of surface engineering
• /
• v.35 no.6
• /
• pp.363-370
• /
• 2002

Empirical equations for the oxide thickness and the weight gain of Zircaloy-4 cladding during the oxidation in high temperature, high pressure steam have been developed. Firstly, the empirical equations for oxide thickness in 1 atm steam in 700~100$0^{\circ}C$ were made, then, the enhancement factor for the steam pressure effects on Zircaloy-4 cladding oxidation in high temperature steam was added. Based on the analysis of the weight fraction of dissolved oxygen in metal layer, empirical equations for the weight gain of Zircaloy-4 in high pressure, high temperature steam were developed. We compare the developed empirical equations with the Baker-Just correlation. The Baker-Just correlation can give a non-conservative estimation of oxidation of Zircaloy-4, depending on the steam pressure. These developed empirical equations can be used for the correct estimation of oxidation of Zircaloy-4 during accident analysis.

• Design & Manufacturing
• /
• v.2 no.3
• /
• pp.22-27
• /
• 2008

Forming of PET bottle was performed by injection-stretch blow molding. Blow molding is process of contacting the dies with air of materials by pressing. In this paper, the aim was to improve reliability of technical stabilization for the PET bottle that is last productive product and process technology which was able to do maximization by a preform performance enhancement of the uniform thickness that took temperature and a characteristic of materials. Preform design and dies manufacture were conducted using injection blow molding analysis results. Therefore thickness error of 5% for PET bottle can be obtained in this paper.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.24 no.4
• /
• pp.379-385
• /
• 2016

Door impact beam plays a key role in minimizing the occupant injury within the side impacted vehicle through preventing intrusion of the impacting vehicle. Steel pipe type door impact beam has been widely adopted since it has simple structure and the overall strength is easily determined according to the pipe size. The brackets welded at pipe ends connect the door impact beam and the door panels by spot welds. In this study, first, the effect of pipe thickness, bracket thickness and door mounting stiffness was respectively analyzed. Next, application of the tailor rolled pipe was examined and several alterations of the bracket mounting method were considered. Application of tailor rolled pipes with superior bracket mounting method showed remarkable strength enhancement and weight reduction possibility in comparison with the current door impact beam.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 1996.10a
• /
• pp.319-322
• /
• 1996

Automatic gauge control algorithm in rolling process is composed of several functions. Among them feedforward control method is used to compensate irregularity of input strip thickness before rolling process. Since it's very difficult to get an explicit relation between the degree of irregularity of input strip and manipulated variables, approximate linear equation like straight line is used in real system. Furthermore parameters included in such static equation should be changed by characteristics of input strip and modified by roll states. Despite this problem, rolling process use variables in feedfroward controller as a constant. Therefore this problem increases the possibilities of irregularity of thickness control. This paper presents an algorithm which can properly infer present states of process and intelligently manipulate the parameter of feedforward controller.

• Proceedings of the Safety Management and Science Conference
• /
• 2003.11a
• /
• pp.351-357
• /
• 2003

The optimum polymer gel electrolyte composition ratio was 23 : 66 : 11 wt% of P(VdF-co-HFP) : PVP =20 : 3), (PC: EC =44 : 22) and TEABF$_4$. And the optimal thickness of polymer gel electrolyte was 50 ${\mu}{\textrm}{m}$. The electrochemical characteristics result of unit cell were 31.41 Fig of specific capacitance, and 3.21$\times$10$^{-3}$ S/cm of ion conductivity. Ion conductivity of polymer gel electrolytes decreased according to added PVP through impedance analysis, and it was higher in 7 wt%, but electrochemical characteristics of unit cell were better in 3 wt% PVP. And for excellent ion conductivity of polymer gel electrolytes, the use of a thin layer electrolyte(20 $\mu\textrm{m}$) was an effective method, but with unit cell application, the best thickness was 50 $\mu\textrm{m}$. Unit cell showed higher capacitance and more stable electrochemical performance when hot pressed between polymer gel electrolyte and electrode. This results from enhancement of the physical contact between the electrode and the polymer gel electrolyte and good accessibility of the liquid electrolyte to the electrode surface.