• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2006.10a
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• pp.138-144
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• 2006

Non-contact transportation of a large-sized glass plate using air cushion for the sputtering system of liquid crystal display panel was considered. The gas is injected through multiple small holes to maintain the force for levitating glass plate. Complex flow field and resulting pressure distribution on the glass surface was numerically studied to design the air injection pad. The exhaust hole size was varied to obtain evenly distributed pressure distribution at fixed diameter of the injection hole. Considering the force for levitating glass plate, the diameter of the exhaust hole of 30 to 40 times of the gas injection hole was recommended.

• Journal of Ocean Engineering and Technology
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• v.21 no.5
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• pp.25-32
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• 2007

The piled-raft foundation, a new design concept, is one of the most effective kinds of foundation for reducing settlement of structures. An alternative piled-raft system with disconnection cap and a sand cushion between the pile and raft was also investigated to compare the influence of ultimate bearing capacity and settlement. Load-settlement relation curves were used to evaluate the ultimate bearing capacity. In the numerical analyses, a plane strain elasto-plastic finite element model (Mohr-Coulomb model) was used to present the response of the piled-raft foundation.

• Journal of Mechanical Science and Technology
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• v.19 no.4
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• pp.976-984
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• 2005

This paper presents the analysis results of dynamics in the billiards game within the frame­work of rigid-body mechanics and a numerical simulation program. The friction exists between the ball and the table bed as well as between the ball and the rail. There are three parts in the dynamic behavior of the ball on the table bed; motion of the ball on the table bed, collision between balls, and collision between the ball and the cushion. During the development of the simulation program, the dynamics problems such as rolling motion and three-dimensional frictional impact motion have been analyzed in detail. The theoretical issues are implemented into a viable graphic simulation program and its efficacy is demonstrated through the experi­mental validation of the billiards game. The resulting analysis results are verified quantitatively and qualitatively using high-speed video camera. Through the experimental tests, it was found that the physical parameters such as coefficients of restitution and friction vary according to the motion variables and corresponding empirical formulations were developed. The simulation and experimental results agree well.

• Journal of Advanced Marine Engineering and Technology
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• v.23 no.6
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• pp.794-805
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• 1999

Pneumatic cushioning cylinders are commonly employed for vibration and shock control. A mathematical simulation model of a double acting pneumatic cushioning cylinder designed to absorb shock loads is presented which is based on the following assumptions; ideal equation of state isentropic flow through a port conservation of mass polytropic thermodynamics single degree of freedom piston dynamics and energy equivalent linear damping. These differential equation can be solved through numerical integration using the fourth order Runge-Kutta method. An experimental study was conducted to validate the results obtained by the numerical integra-tion technique. Simulated results show good agreement with experimental data. The computer simulation model presented here has been extremely useful not only in understanding the has been extremely useful not only in understanding the basic cushioning but also in evaluating different designs.

• Earthquakes and Structures
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• v.15 no.2
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• pp.215-225
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• 2018

To reach a better foundation treatment project, an optimized analysis of composite foundation was studied in the field of hydraulic engineering. Its unique characteristics in hydraulic engineering were concluded. And, the overall and detailed analysis of the composite foundation model established was carried out. The index parameters of the vertical reinforced rigid pile composite foundation were formulated. Further, considering the unique role of cushion in hydraulic engineering, its penetration and regularity were analyzed. Then, comparative and optimized analyses of cushion multistage physical dimensions and multistage material characteristics were established. The parameters of the piles distance were optimized and the multilevel scientific and reasonable parameters information was obtained. Based on the information of these parameters, the practical application was verified. It effectively supported the effective application of vertical reinforcement rigid pile composite foundation in hydraulic engineering. The service mechanism of composite foundation was fully analyzed.

• Journal of Auto-vehicle Safety Association
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• v.6 no.2
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• pp.55-60
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• 2014

To verify the performance of roadside safety facilities, strength and occupant protection test are performed by evaluation criteria. Strength test use a truck and occupant protection test use a sedan. Strength perfomance is analyzed pass rate by post lateral resistance of the safety barrier. Occupant protection performance is analyzed from THIV(Theoretical Head Impact Velocity) and PHD(Post-impact Head Deceleration) by crash cushion test.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.07a
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• pp.226-232
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• 2002

포장이란 유통단계에서 제품이 파손되거나 손상되지 않도록 보호하는 수단이며 원가절감과 생산성 향상을 통한 상품성의 제고는 물론 부가가치 증대 및 매출신장에도 큰 영향을 미친다. 더욱이 포장재료의 재활용, 환경친화성 신소재 개발 등에 따른 포장의 중요성에 대한 인식의 전환이 요구된다. 최근 환경보호 문제가 전 세계적으로 확대되면서 포장폐기물 처리의 중요성이 새로이 인식되어, 포장완충재의 주종을 이루던 플라스틱계 재료의 사용이 환경오염과 관련하여 엄격히 규제됨에 따라 환경친화력이 우수한 지류완충재의 사용이 증가하고 있으며, 농산물의 직거래가 활발해지고 생산자 실명제를 도입한 결과 농산물 포장용 골판지 상자의 기능이 운반용에서 판매용으로 전환되고 있으며 화려한 디자인과 필요이상의 강도로 설계, 유통되고 있어 과대포장이 심각한 수준에 달하고 있다. 유통과정 중 제품을 적절히 보호하고 적정 포장비로 물류합리화를 위해서는 제품의 완충 및 적정포장설계가 필요하며, 이를 위한 첫 번째 조건이 완충재 자체에 대한 특성의 평가와 이의 객관적 자료화이다. (중략)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.1004-1006
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• 2014

This study was conducted to improve the understanding of factors affecting an automobile seat cushion in dynamic conditions. When there are two dummies on the seat to measure each places respectively at once, the shape of the transfer function changes because the dummies affect each other as if they are linked with some kind of a spring when under excitation. A simple two-degree-of-freedom linear model is used to define a translational stiffness of dynamic coupling phenomenon. The cushion deflection model was created to find the relation between dynamic coupling and distance. Experimental set-up was made to compare with the two-degree-of-freedom linear model. The dynamic coupling factor could be utilized to improve the dynamic comfort of automobile seats.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.787-788
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• 2009

• Transportation Technology and Policy
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• v.8 no.4
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• pp.35-44
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• 2011