• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.555-558
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• 2005

If sound pressure values on boundary are available, then we can predict the sound field in it. Similarly, we can reproduce sound field by manipulating sound pressure values on boundary. In this paper, a noble method of sound reproduction using this concept is introduced and evaluated for the case in which sound field is 2-D half-infinite plane by computer simulation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1425-1431
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• 2006

In this study, An analysis of correlation between the vibration transmissions and the dynamic characteristics for floor impact sound insulation materials through model test was carried out. As the results, the correlation coefficients between the vibration transmissions and the dynamic characteristics for floor impact sound insulation materials were over 0.8 at the heavy and light floor impact source and less dynamic stiffness was more effective in reducing the vibration transmission.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.811-816
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• 2011

This study includes investigation on sound transmission phenomena through a structural panel including structural vibration and feedback control methodology to minimize the transmission. Focus is placed on finding the relation between vibration pattern and sound transmission, and on finding optimal sensor and actuator location. A simple analog feedback control circuit is designed and implemented to verify the approach.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.2
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• pp.184-191
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• 2009

This study examined small-size specimen's effectiveness that is used to evaluate floor impact sound performance. Floor impact sound level of small-size specimen is higher than full-size. This is due to excessive impact power of Bang machine. Impact hammer that has small impact power relatively can solve this problem. But, according to the size of specimen, mode shape and frequency that influence to structural borne sound is changed. Slab mode of full-size specimen was changed to frequency design of resilient materials. But in case of small-size specimen, there is no change of vibration mode by resilient materials change, Vibration mode of small-size specimen is the same. Therefore, it is not proper that use small-size specimen in floor impact sound estimation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.498-501
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• 2006

When an object or objects, rigid or flexible, presents in incident sound field, the sound wave is scattered. This, we call, is scattered sound field. It, of course, depends on the amplitude and the direction of the incident sound field as well as the geometry and the surface impedance of the scatterer(object). This paper addresses the way to measure scattered sound field by using arbitrary incident sound wave. This means that the method can decompose the scattered field from measured sound field with respect to any magnitudes and directions of incident plane-waves.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.332.2-332
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• 2002

Booming sound is one of the most important interior sound of a passenger car. The conventional booming noise research was focused on the reduction of the A-weighted sound pressure level. However A-weighted sound pressure level can not give the whole story about the booming sound of a passenger car. In this paper, we employed sound metric which is the subjective parameter used in psychoacoustics. (omitted)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1002-1006
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• 2000

It is diffuse sound field that measuring condition of absorption ratio and sound transmission loss for material consist of building are measured in reverberartion room and on-site. In this study, for upkeeping diffuse sound field in reverberation room, it is measured and etimated that sound field is effected according to sound source lacation and characteristics of emission directivity for sound source.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.4 s.97
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• pp.412-420
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• 2005

This article proposes analytical solutions for sound radiation from radial vibration modes of a thick annular disk. Structural eigensolutions are calculated using the transfer matrix method. The far-field sound pressure distribution is obtained using two alternate methods. In the first method, pressure is calculated using the Rayleigh integral technique. The second method treats sound radiating radial surfaces as cylindrical radiators of finite length. The Sinc function approach is employed for calculations. Acoustic powers and radiation efficiencies of radial modes are also determined from the far-field sound pressure calculations. Analytical predictions match well with measured data as well as computational results from a finite element code in terms of structural eigensolutions and from a boundary element code in terms of sound pressure, directivity etc.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.257-260
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• 2004

This study aims to evaluate factors of ceiling structure influencing to the floor impact sound. For this reasons, we measured the vibration of ceiling and the floor impact sound by ceiling structure. The main results from this study are that ceiling structure makes worse to non-ceiling structure for an effect of air layer in heavy-weight floor impact sound. But it has an effect on light-weight floor impact sound about $2\sim8dB$.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.6
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• pp.415-422
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• 2003

In an apartment buildings, the floor Impact sound from upstairs has been regarded as a main source of noise causing discontentment among occupants. To set the optimum design for sound insulation, it is necessary to suggest the useful tools or technique that predict the floor impact sound. The purpose of this study is to suggest the supplementary formula(equation) and constant k considering vibration transmissibility in order to predict more precisely heavy floor impact sound by Impedance Method that have been briskly studied in Japan from comparing the measured values with the predicted values. The analyzed results had showed that if the damping material was glass wool or rubber, k=5 was proper and if the damping material was polystyrene foam, k>5 was desirable.