The Journal of the INCE of Japan
Online ISSN : 1883-7506
Print ISSN : 0386-8761
Volume 36 , Issue 1
Showing 1-3 articles out of 3 articles from the selected issue
Dissertation—Contribution
  • Takayuki Koizumi, Nobutaka Tsujiuchi, Satoshi Morita, Hirofumi Wada, H ...
    2012 Volume 36 Issue 1 Pages 81-88
    Published: February 01, 2012
    Released: January 16, 2020
    JOURNALS FREE ACCESS

    The statistical energy analysis (SEA) is an effective method to predict noise and vibration in the high-frequency band. To predict vibration and noise accurately by using SEA, it is important to estimate parameters called loss factors and modal density. The power injection method (PIM) is an effective experimental method to estimate parameters accurately. It is necessary to measure the vibration in a lot of points in experiment. The number of measurement point influences estimated result at the PIM. However, there is no concrete guideline concerning the measurement point. In addition, it is necessary to measure the vibration in all elements to estimate parameters, when the structure is changed. This paper described that the difference of the measurement point influences the analytical result. And we estimated the loss factor from the result of an experiment in only of the attached element, when damping material was attached to the subsystem. As a result, we can present the concrete guideline concerning decision of the measurement points. And it is possible to omit the process of estimating the loss factor after the structure-changing by using the proposed technique in the study.

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  • Sunao Kunimatsu, Yoshihiro Hirao, Yasutoshi Kitamura
    2012 Volume 36 Issue 1 Pages 89-99
    Published: February 01, 2012
    Released: January 16, 2020
    JOURNALS FREE ACCESS

    In the present state, prediction of vibration in vibration pollution has been considered for every source of vibration. The ground vibration near the house is estimated mainly by assuming the ground to be the homogeneous half-space, and using the Bornitz’s empirical equation. In this method, the factor for attenuation characteristic by distance in Bornitz’s equation is calculated by multiple linear regression analysis from the measured vibration level at observation points near the source of excitation and in ground propagation path. Moreover, the vibration level in the house is estimated by adding 5 dB as the amount of vibration amplification to the vibration level at the ground near the house. However, it is known that the frequency characteristics near the source of excitation changes in the propagation process from source to the house and the magnitude of vibration does not decrease monotonously by distance. Therefore, in this paper, the prediction method of the vibration in the detached house in consideration of frequency was studied while pointing out the importance of the frequency characteristic of vibration in the propagation process from the source of excitation.

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Dissertation—Technical Report—Contribution
  • Hiroshi Yoshinaga, Shingo Andou, Shinri Sone
    2012 Volume 36 Issue 1 Pages 100-105
    Published: February 01, 2012
    Released: January 16, 2020
    JOURNALS FREE ACCESS

    Traffic volumes and A-weighted sound power levels(LWA)are the bases for the prediction or the estimation of A-weighted equivalent continuous sound pressure level(LAeq)of road traffic noise. The LWA values in a certain 1999 document are generally used by the Ministry of Land, Infrastructure, Transport and Tourism. As more than 10 years have passed since the LWA values were published, the continuous usage of the values has been validated. The LWA measured in 2010 were almost equal to the values in the 1999 document, and the estimated LAeq based on the values in the 1999 document were accurate. The validation of continuous usage of the values in the 1999 document to estimate road traffic noise is confirmed.

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