• Korean Chemical Engineering Research
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• v.51 no.5
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• pp.580-586
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• 2013

In this paper, polymer composite membranes and ceramic composite membranes were prepared in order to compare differences in pervaporation performances relative to the support layers. PVDF was used for the polymer support layers, and $a-Al_2O_3$ was used for the ceramic support layers. For active layer was coated for PDMS, which is a rubbery polymer. The characterization of membranes were analysed by SEM, contact angle, and XPS. We studied performances relative to the composite membrane support layers in the ABE mixture solutions. The results of the pervaporation, the flux of the ceramic composite membrane was shown to be $250.87g/m^2h$, which was higher than that of polymer composite membranes, at $195.64g/m^2h$. However, it was determined that the separation factor of the polymer composite membranes was 31.98 which were higher than that of the ceramic composite membranes, at 20.66.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.5
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• pp.75-85
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• 1998

This paper presents the procedures and technique of the decision on the decision on the mount in a diesel engine development newly. To assess the vibration chara- cteristics of the engine plus transmission, their inertia moments are calculated for three engine versions. i.e., NA(Naturally Aspirated), TC(Turbocharged) and TCI(Turbocharged and Intercooled). These data are used to determine the mount layout and stiffness values affecting the noise quality of an engine as well as a vehicle. The main purpose of this paper is to design the mount rubber having the optimal stiffness characteristics through the investigation of the calculation results and the mount conditions when an engine is installed in a vehicle using the existing engine mount room. Thus, this paper describes the optimal mount positions, rubber stiffnesses, natural frequency, mode shapes and so on using ADAMS program to apply the newly developed engines to three different vehicles.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.678-678
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• 2009

환경 소음,진동 개선의 측면에서 철도 레일 하부로 전달되는 진동 및 구조소음을 효과적으로 차단하기 위하여 국내에서도 탄성지지 구조의 플로팅 슬라브를 적용하는 경우가 증가하고 있다. 플로팅 슬라브 구조설계에 있어 주안점은 슬라브 자체 중량에 비하여 열차 중량과 열차 주행간에 발생하는 동하중이 2$\sim$3배 이상 높아 열차 주행 안정성을 고려해야 하는 점이며 열차의 고속화 경향에 따라 동하중의 증가는 더욱 커지고 있다. 특히, 열차의 구조 동특성과 동하중의 주파수 특성을 고려할 경우 슬라브 구조의 동적 설계변수(고유진동수, 감쇠비 등) 결정이 매우 제한되고 있음을 고려하면 탄성지지부의 감쇠 및 강성의 가변 특성의 부여는 매우 중요하다 할 수 있다. 본 연구에서는 MR 댐퍼와 MR 방진고무 등의 반능동 소재를 사용하여 열차 주행간에 발생하는 탄성지지 슬라브의 진동을 제어하는 시뮬레이션을 수행함으로써 적용 가능성을 확인하고자 한다.

• The Journal of the Acoustical Society of Korea
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• v.8 no.1
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• pp.38-47
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• 1989

The optimal mounting system for reciprocating comperssor supported on a flexible is designed. Four short hollow rubber cylinders are used as mounting pads, and so the thickness, diameter, height and location of the rubber mounts are considered as design parameters. The optimal mounts parameters which give the smallest force transmittance, are obtained by Constrained Rosenbrock Method.

• 프린팅코리아
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• v.8 no.9
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• pp.54-59
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• 2009

앞으로 환경문제에 대한 대책은 더욱 급속한 스피드로 진행되어 갈 것이다. 그 가운데 품질과의 양립이 중요해지지만, 사용하는 인쇄기의 성능을 최대한 끌어올려 높은 인쇄품질을 실현하려면 사용하고 있는 자재의 밸런스가 좋은 상태를 유지해야 한다. 오존층의 파괴 등 지구 온난화를 비롯한 지구 규모에서의 환경보호에의 대책은 기업이 솔선수범하여 도전할 테마다. 동시에 인체에도 영향이 적은 제품개발이 무엇보다 중요하다. 일반적으로 인쇄는 잉크 또는 롤러와 밀접한 관계를 가지고 있다. 잉크의 특성으로 인해 인쇄물의 건조가 되지 않거나 잉크의 지지도가 나쁘게 되며 세척에 많은 시간을 요구하게 된다면 인쇄 품질을 기대하기는 어려울 것이다. 또한 롤러를 반복적으로 세척하고 새로운 것으로 교체하는 경우에도 작업 능률의 저하를 가져 올뿐만 아니라 작업자의 피로를 유발하여 안전사고 위험에도 쉽게 노출될 수 있다. 이에 이러한 문제점들에 대해 알아보았다.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.4
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• pp.307-316
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• 2002

In order to evaluate the deformation and stiffness of frame structure for fishery, composed of unit platforms which made of two concentric high density polyethylene buoys fixed by clamps and belts and rubber hinge components, under wave, the structural analysis for the square type of the structure was carried out by using finite element methods. The accurate physical properties of rubber hinge components determined by material tests were an important parameter to evaluate more reliable structural stability for the structure. The idealization to beam element with equivalent stiffness and rubber element with linearity for rubber hinges was necessary for the modeling of rubber component which has hyper-elastic characteristics. In addition, it was shown that the structural response of the structure under wave was larger in the hogging condition than that of in the still water or in the sagging condition.

• Journal of the Korean Geosynthetics Society
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• v.9 no.3
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• pp.9-18
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• 2010

A series of model tests were performed to investigate the load transfer by soil arching in geosynthetic-reinforced and pile-supported(GRPS) embankment systems. In the model tests, model piles with isolated cap were inserted in the model container and geosynthetics was laid on the pile caps below sand fills. The settlement of soft ground was simulated by rubber form. The loads acting on pile caps and the tensile strain of geosynthetics were monitored by data logging system. At the given interval ratio of pile caps, the efficiency in GRPS embankment systems increased with increasing the height of embankment fills, then gradually converged at constant value. Also, at the given height of embankment fills, the efficiency decreased with increasing the pile spacing. The embankment loads transferred on pile cap by soil arching increased when the geosynthetics installed with piles. This illustrated that reinforcing with the geosynthetics have a good effect to restraint the movement of surrounding soft grounds. The load transfer in GRPS embankment systems was affected by the interval ratio, height of fills, properties of grounds and tensile stiffness and so on.

• Membrane Journal
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• v.22 no.2
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• pp.142-154
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• 2012

In order to remove $CO_2$ from the DME plant process, we investigated the composite membrane with rubbery polymers as the separation layer and its separation performance of $CO_2$ and $H_2$. Hollow fiber membranes for supporting layer were prepared by solution spinning method. In case of using PDMS as a separation layer, the composite membranes showed the permeation rates of $CO_2$ were over 300 GPU and minimum $CO_2/H_2$ selectivitties were 4.3 and in case of using PEBAX as a separation layer, the composite membranes showed the permeation rates of $CO_2$ were over 120 GPU and minimum $CO_2/H_2$ selectivities were 5.

• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.3
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• pp.305-315
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• 1986

Redesign of the mounting system to minimize vibration of a variable displacement engine through computer simulation is considered. A three degree of freedom model is established for an in-line four-cylinder automobile engine with a three point mounting system. The engine mount locations and angles, and isolator sizes are chosen as design parameters. Constraints on isolator deformations and design parameters are imposed. The gradient projection method is utilized for optimization. Simulation studies show significant vibration reduction can be obtained especially at idling speed.

• 정보저장시스템학회:학술대회논문집
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• 2005.10a
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• pp.215-216
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• 2005

Nowadays, mobility as well as basic performances has been the important performance index of hard disk drive, It makes a system unstable to satisfy mobility, huge storage capacity and high transfer rate. Shock and vibration analysis has been important because hard disk drive could be exposed by external shock and vibration. The probability of this situation has been increasing. In this research, each component and the whole system of 2.5in HDD are made to a finite element model. Results of finite element analysis are compared with the results of experimental modal analysis. Shock analysis is executed for 2.5in hard disk drive.