• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.232-233
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• 2011

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.234-237
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• 2011

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.2
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• pp.247-254
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• 2008

Resilient materials are generally used for the floating floors to reduce the floor impact sound. Dynamic stiffness of resilient material, which has the most to do with the floor impact sound reduction. The resilient materials available in Korea include EPS(styrofoam), recycled urethane types, EVA(ethylene vinylacetate) foam rubber, foam PE(polyethylene). glass fiber & rock wool, recycled tire, foam polypropylene. compressed polyester, and other synthetic materials. In this study, we tested dynamic stiffness of resilient material and floor impact sound reduction characteristic to a lot of kinds of resilient materials. It was found that dynamic stiffness of multi-layered damping material could be estimated if know value of each layer that compose whole structure. And the test showed that the amount of the heavy-weight impact sound reduction appeared by being influenced from this dynamic stiffness of resilient material. The dynamic stiffness looked like between other resilient materials, a similar to the amount of the heavy-weight impact sound reduction was shown.

• KIEAE Journal
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• v.4 no.3
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• pp.71-78
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• 2004

Apartment housing is a widely-spread type in Korean housing market. Nevertheless, it has caused serious problems such as traditional community corruption, unsafe structure, defects and litigation from noise. Noise, especially in concrete structure for apartment housing, is hardly controlled in proper to prevent sound transmission between upper and lower families with existing system. In foreign countries, there are floating floor system to enhance the noise control performance in multi-family housing. This study is to examine the impact sound insulation performance of floors according to the different P'yong and Layers by field measurement in highrise building.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.572-579
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• 1998

In this paper, an analytical model for analyzing the interaction between train and floating slab track is presented. Train is modelled by 4-lumped masses system which are composed of a carbody supported by secondary suspension, a bogie frame supported by primary suspension, and two wheelsets supported by nonlinear Hertzian springs. In the track model, rail is considered to have a distributed mass and to be supported discretely at sleepers above ballast on slab. The slab supported by discrete isolators put on fixed floor is modelled by finite beam elements. Numerical analyses are carried out to examine anti-vibration effect of the GERB slab track which is same type laid in Puchon station on the subway No. 7 Line.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.30.5-30
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• 2001

This paper describes a new design of blimp having wheeled vehicle part. This system can work both on the ground using wheeled vehicle and in the air using the floating capability of the blimp part. The passive wheeled mechanism in the vehicle part enables the stable taking off, landing on as well as it is greatly helpful to keep a stationary position on the floor. On the other hand, the floating capability enables the wheeled blimp to fly freely regardless of the ground condition or obstacles. The wheeled blimp can be used as an agent robot for the tole-presence application. Using multimedia devices such as camera, speaker, LCD and microphone mounted on the blimp surface, this system can get necessary information at the local site and communicate with person from a distance. As a typical tele-presence application, the wheeled blimp is currently being developed to a tole-guidance robot working in public indoor areas such 35 exhibition halls, departments, hospitals, etc ...

• Structural Engineering and Mechanics
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• v.46 no.3
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• pp.371-385
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• 2013

Vibration isolators and anti-vibration mounts are ideal, for example, in creating floating floors for gymnasiums, or performance spaces. However, it is well-known that there are great difficulties on isolating vibration transmission in structural steel components, especially steel floors. Besides, the selection of inertia blocks, which are usually used by engineers as an effective vibration control measure, is usually based on crude methods or the experience of the engineers. Thus, no simple method or indices have been available for assessing the effect of inertia blocks on vibration isolation or stability of vibratory systems. Thus, the aims of this research are to provide further background description using a FE model and present and implement a modal approach, that was validated experimentally, the latter assisting in providing improved understanding of the vibration transmission phenomenon in steel buildings excited by a velocity-source type of excitation. A better visualization of the mean-square velocity distribution in the frequency domain is presented using the concept of modal expansion. Finally, the variation of the mean-square velocity with frequency, whilst varying mass and/or stiffness of the coupled system, is presented.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11b
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• pp.69-72
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• 2005

In this paper, FSTL(field sound transmission loss) measured in the mock-up is studied and compared to the STL measured in laboratory. A mock-up is built by using 6t steel plate, and two identical cabins are made where 25t or 50t panel is used to construct wall and ceiling inside the steel structure. Various wall panels and ceilings are tested, where the effects of U/T, sealing, panel thickness, ceilings are studied. It is shown that the effect of ceiling thickness is negligible and FSTL is lower than STL by 5-7 dB due to several flanking paths.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.296-299
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• 2004

단열 완충재의 하부단면에서 양각 형태가 전체 면적에서 .차지하는 비율에 따라 진동 충격음 저감량을 실험하였다. 양각 형태가 차지하는 비율이 높더라도 진동 충격음 저감량에는 큰 성능을 나타내지 않았다. 바닥 구조에서 슬래브와 상판 사이에 단열완충재를 설치할 경우 중량 충격음이 오히려 증가하는 경향을 보이고 있다. 이것은 뜬 바닥 구조에서 완충재의 설치로 인하여 슬래브와 상판간의 거동이 다르게 발생하기 때문이다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.942-945
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• 2005

The purpose of this study is to suggest a fundamental data for change of dynamic properties according to the loading time of resilient materials. 18 kinds of resilient materials included 4 representative types were measured at the load time of 24hours and 2hours by the method of Korea standard (KS F 2868) measuring the dynamic stiffness and the loss factor of materials under floating floors. As a result, the dynamic stiffness was increased rapidly in case of expandable polystyrene and rubber materials according to the load time, especially before 2 hours. The loss factor was represented that rubber materials with high elasticity are high, and expandable polystyrene, polyester, poly ethylene materials with low elasticity are low.