• Journal of the Korea Institute of Building Construction
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• v.23 no.6
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• pp.761-772
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• 2023

The fire resistance design of timber structures involves calculating the residual section based on charring depth, which is then utilized in structural design. Charring depth is determined from fire-resistance test results in Korea, which currently do not account for the charring properties of the adhesive used in Glued Laminated Timber(GLT) production. This study fabricated GLT using various adhesives employed in domestic GLT production, comparing the charring properties by adhesive type and the fire resistance performance relative to the directionality of the laminated surface. Melamine demonstrated the most advantageous fire resistance performance, followed by resorcinol and polyurethane. Furthermore, it was established that the laminated section exhibited a higher charring rate, influenced by the adhesive, compared to the laminated surface, which significantly impacts the fire resistance performance.

• 대한공업교육학회지
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• v.34 no.2
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• pp.321-330
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• 2009

This study presents the blow molding of injection stretch-blow molding process for PET bottle. The numerical analysis of the blow molding of PET bottle is considered in this paper using CAE with a view to minimize the thickness difference. In order to determine the design parameters and processing conditions in blow molding, it is very important to establish the numerical model with physical phenomenon. In this study, a shell model with thickness has been introduced for the purpose and blow simulations with 3-type blow process condition are carried out. The simulations resulted in the thickness distribution in good agreement with the physical phenomenon. Also, from the result of numerical analysis, we appropriately predicted the thickness distribution along the PET bottle wall and Using the result of numerical analysis we apply the preform design and blow molding process condition for optimization.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.4749-4755
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• 2014

In this study, to maximize the heat release from the heat generating environment, such as a high-capacity inverter, the heat release performance of the extruded-type heat sinks with the variation of the base thickness were investigated using the experimental and numerical methods. The base thickness was varied from 5 to 14 mm. The heat release was characterized by the amount of heat released through the heat sink, the surface temperature of heat sink base between the heat sources, and temperature of heat sources. The surface temperatures between heat sources and the amounts of heat release were improved more as the base thickness was decreased. In contrast, the temperatures of the heat sources decreased with increasing base thickness. Based on the case study of these heat sinks, it is believed that a heat sink with a 9.5mm-thick base was optimized for the heat release.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.698-701
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• 2013

This paper has presented the change of subthreshold swings for gate oxide thickness of asymmetric double gate(DG) MOSFET, and solved Poisson equation to obtain the analytical solution of potential distribution. The symmetric DGMOSFET is three terminal device. Meanwhile the asymmetric DGMOSFET is four terminal device and can separately determine the bias voltage and oxide thickness for top and bottom gates. As a result to observe the subthreshold swings for the change of top and bottom gate oxide thickness, we know the subthreshold swings are greatly changed for gate oxide thickness. Especially we know the subthreshold swings are increasing with the increase of top and bottom gate oxide thickness, and top gate oxide thickness greatly influences subthreshold swings.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.12
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• pp.2939-2945
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• 2014

This paper has analyzed the change of threshold voltage for oxide structure of symmetric and asymmetric double gate(DG) MOSFET. The asymmetric DGMOSFET can be fabricated with different top and bottom gate oxide thickness, while the symmetric DGMOSFET has the same top and bottom gate oxide thickness. Therefore optimum threshold voltage is considered for top and bottom gate oxide thickness of asymmetric DGMOSFET, compared with the threshold voltage of symmetric DGMOSFET. To obtain the threshold voltage, the analytical potential distribution is derived from Possion's equation, and Gaussian distribution function is used as doping profile. We investigate for bottom gate voltage, channel length and thickness, and doping concentration how top and bottom gate oxide thickness influences on threshold voltage using this threshold voltage model. As a result, threshold voltage is greatly changed for oxide thickness, and we know the changing trend greatly differs with bottom gate voltage, channel length and thickness, and doping concentration.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.755-758
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• 2014

This paper has analyzed the change of threshold voltage for oxide structure of symmetric and asymmetric double gate(DG) MOSFET. The asymmetric DGMOSFET can be fabricated with different top and bottom gate oxide thickness, while the symmetric DGMOSFET has the same top and bottom gate oxide thickness. Therefore optimum threshold voltage is considered for top and bottom gate oxide thickness of asymmetric DGMOSFET, compared with the threshold voltage of symmetric DGMOSFET. To obtain the threshold voltage, the analytical potential distribution is derived from Possion's equation, and Gaussian distribution function is used as doping profile. We investigate for bottom gate voltage, channel length and thickness, and doping concentration how top and bottom gate oxide thickness influences on threshold voltage using this threshold voltage model. As a result, threshold voltage is greatly changed for oxide thickness, and we know the changing trend very differs with bottom gate voltage, channel length and thickness, and doping concentration.

• Journal of the Microelectronics and Packaging Society
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• v.7 no.2
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• pp.13-19
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• 2000

Shear strengths of BGA solder joints on Cu pads were studied for Cu-containing Sn (0, 1.5, and 2.5 wt.% Cu) and Sn-40Pb (0 and 0.5wt.% Cu) solders, with emphasis on the roles of the Cu-Sn intermetallic layer thickness and the roughness of the interface between the intermetalic layer and solder. The shear strength test was performed for as-soldered solder joints with various soldering reaction times up to 4 min. The addition of Cu to the pure Sn solder results in an enhanced growth of the intermetallic layer whereas the effect of Cu addition to the Sn-40Pb solder is primarily on the reduction of the roughness of the intermetallic/solder interface. The critical thickness of the intermetallic layer for a maximum shear strength depends on the solder materials, which was measured to be ~ 2.3 $\mu\textrm{m}$ for Sn-Cu solders and ~ 1.2 $\mu\textrm{m}$ for Sn-Pb-Cu solders. The shear strength at the critical intermetallic layer thickness seems to increase as the intermetallic/solder interface becomes rougher. This is in accordance with the observation that the sheared fracture occurred initially within the solder tends to shift towards the intermetallic/solder interface as the intermetallic layer grows above the critical thickness.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.275.2-275.2
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• 2016

본 연구에서는 pilot급 대면적 roll-to-roll 스퍼터를 이용하여 상온에서 제작한 ITO/Cu/ITO 다층 투명 전극의 유연 투명 히터 적용 가능성과 투명 전극의 면저항이 히터의 input 전압에 미치는 영향을 연구하였다. 상부/하부 ITO 두께를 35 nm로 고정하고 Cu interlayer의 두께를 변수(4 nm~ 12 nm)로 하여 제작한 ITO/Cu/ITO 다층 투명 전극의 전기적, 광학적, 구조적, 표면 특성을 분석하고 삽입된 Cu의 역할을 연구하였다. Cu 두께의 증가에 따라 면저항은 25.4 Ohm/square에서 5.80 Ohm/square로 급격히 감소하나 투과도 역시 75.51%에서 62.62%로 감소하였다. 유연 투명 히터에 적용하기 위해 최적화된 ITO/Cu/ITO 다층 박막의 유연성을 다양한 밴딩 테스트를 통해 분석하였으며, 10,000번의 반복 굽힘 시험에도 저항의 변화가 없음을 관찰 할 수 있었다. 이러한 저저항, 고투과, 고유연 ITO/Cu/ITO 다층 투명 전극을 이용하여 유연 투명 히터를 제작하였으며, Cu interlayer의 두께에 따른 유연 투명 히터의 발열 특성을 평가하였다. 유연 투명 히터의 온도를 100도에 이르게 하기 위한 Saturation input voltage는 투명 전극의 면저항에 가장 크게 영향을 받았고, 면저항이 낮아질수록 더 낮은 saturation input voltage에서 100도에 도달함을 알 수 있었다. Cu interlayer의 두께가 12 nm 일 때에는 6V의 input voltage로도 유연 투명 히터의 온도가 100도에 도달함 알 수 있었다. 이를 통해 roll-to-roll 스퍼터로 제작된 대면적 ITO/Cu/ITO 다층 투명 전극이 차세대 유연 투명 히터용 투명 전극으로 적용 가능성이 매우 높음을 확인하였다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.6
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• pp.599-606
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• 2010

In the present study, actuators with diaphragms of different thickness and chambers of different diameter are fabricated to examine experimentally how the behavior characteristics of the actuator diaphragm in a thermopneumatic micropump are affected by diaphragm thickness and chamber diameter under various operating conditions with different values of input voltage and frequency. The actuator comprises a microheater set on Pyrex glass, a chamber, and a diaphragm. For all values of the input energy, as the frequency decreases below 10 Hz, the maximum center deflection of the diaphragm greatly increases irrespective of diaphragm thickness and chamber diameter. At low frequencies, as the heat energy supplied to the chamber increases, the center of deflection of the diaphragm increases; the magnitude of deflection is high for thin diaphragms and for diaphragms whose chambers have small diameters. At frequencies higher than 10 Hz, all the design variables such as diaphragm thickness, chamber diameter, and the input energy have negligible effect on the center deflection of the diaphragm.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.3
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• pp.179-184
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• 2003

This study investigated the relationship of fuel weight and depth together with slope on the spread of forest fire. Fire spread was faster on the greater slope in forested land. Fire had a greater spread rate with lighter fuel weight. The thickness of the fuel bed and forest fire spread rate were not related. The fire spread rate was closely related to the slope and weight of the fuel bed (significant at 0.01, 0.05, respectively). The thickness of the fuel bed was not significant (0.05).