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Lee, Byung-Kwon;Jeon, Jin-Yong
- Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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- 2002.11a
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- pp.351.2-351
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- 2002
The overall noise reduction was compared in regard to the vibrational characteristics of floor impact noise in a multi story residential building which has several noise reduction treatments. The vibration through its structural elements such as wall, floor and ceiling and sound emitting were investigated for each insulation treatment. It was found that, in case of heavy-weight impact noise, the vibration energy is emitted mostly from ceiling, but for the light-weight impact noise, most of the energy comes through ceiling and walls. (omitted)
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이정학;서종수
- Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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- 2003.05a
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- pp.749-754
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- 2003
In this paper, we introduce the measurement of the underwater noise with 32channel hydrophone array of Samsung CAvitation Tunnel (SCAT) and the detection technique of noise sources by using the beam-forming method. Measurement and way signal Processing under fluid flow are essential works for the underwater acoustics, especially for the detection of noise sources. As the acoustic impedance of the water is relatively high and the tunnel is an enclosed system, we have to consider the interaction between tunnel and water together with the reflection of noise in the beam-forming technique. Also, for a hydrophone array system that is fixed on one side of tunnel wall as done in SCAT is liable to suffer from some limitations in the detection of the noise sources with the array, we discuss these limitations particularly on the frequency range and spacing of noise sources.
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배동명;신창혁;김도균
- Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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- 2003.05a
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- pp.938-943
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- 2003
In accordance with the tendance to construct high-rise apartment buildings, the elevators tend to high speed up and to the drive more frequently. So, the problem of vibration and noise produced by the operating elevator has been treated as an important subject all the more. In this research, the actual levels of vibration and noise which generated and transmitted by the elevator operation in apartment buildings were measured and these characteristics were analysed to examine the countermeasures to be able to reduce the these vibration and noise level, and to design the several vibration and noise control.
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설한신;이수갑;표상우;서정천
- Journal of the Society of Naval Architects of Korea
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- v.41 no.2
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- pp.21-32
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- 2004
The non-cavitating noise of underwater propeller is considered numerically in this study. The main purpose is to analyze non-cavitating noise from underwater propellers in various operating conditions with different configurations. Noise is predicted by using time-domain acoustic analogy, boundary element method, and computational hydro-acoustics. The flow field is analyzed with potential-based panel method, and then time-dependant pressure data are used as the input for Focus Williams-Hawkings formulation to predict far field acoustics. Furthermore, boundary element method and computational hydro-acoustics are also considered to investigate duct propeller and ducted multi-stage propeller to consider the reflection and diffraction of sound waves. With this methodology, noise intensity and directivity of each noise sources could be well analyzed.
https://doi.org/10.3744/SNAK.2004.41.2.021 인용 PDF KSCI

Kang, S.W.
- Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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- 2013.10a
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- pp.658-663
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- 2013
A new formulation of the MNDIF method is introduced to extract highly accurate eigenvalues of concave acoustic cavities with arbitrary shapes. It is said that the MNDIF method cannot yield accurate eigenvalues for concave cavities. To overcome this weak point, a new approach of dividing a concave cavity into two convex domains is proposed. The validity of the proposed method is shown through a case study.
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