• The Journal of the Acoustical Society of Korea
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• v.37 no.5
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• pp.378-386
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• 2018

The present paper suggests the original form of the bell pavilion for the King Song-Dok bell which is one of the precious national treasure of Korea. In order to this, many literatures were reviewed including both historical and acoustical references. As the results, the model of the bell pavilion for the King Song-Dok bell is suggested as follows considering acoustical characteristics of the King Song-Dok bell and the traditional Korean bells ; 1) The bell pavilion has the rumbling puddle beneath the bell on the ground floor for resonance of sound 2) Many lumbers are used for columns and beams rather than boards since natural frequencies of the bell are 64 Hz and 168 Hz so that the sound absorption of the low frequency sound may not be occurred. 3) Only some boards may be used for the area between upper and middle molding of lintel in order to prevent of direct sunlight and sea breeze since this type of structure were used for bell pavilion of the same age. 4) Square form with the odd number of 3 or 5 Kans is adopted for bell pavilion considering the weight and the size of the bell which had been used traditionally 5) Finally, half-hipped structure is used for the roof of the bell pavilion which was the predominant form of the age.

• Science of Emotion and Sensibility
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• v.15 no.2
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• pp.201-208
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• 2012

The objectives of this study were to investigate the psychoacoustic properties of PTFE(Poly tetra Fluoroethylene) laminated vapor permeable water repellent fabrics which are frequently used for sportswear, to examine the relationship among fabrics' basic characteristics, mechanical properties and the psychoacoustic properties, and finally to propose the predicting model to minimize the psychoacoustic fabric sound. A total of 8 specimens' frictional sound were recorded and Zwicker's psychoacoustic parameters such as loudness(Z), sharpness(Z), roughness(Z), and fluctuation strength(Z) were calculated using the Sound Quality Program. Mechanical properties of specimens were measured by KES-FB system. Loudness(Z) of specimen D-1 was the highest, which means the rustling sound of the specimen D-1 was the most noisy. Statistically significant difference among film type was observed only in loudness(Z) for fabric sound. Based on ANOVA and post-hoc test, specimens were classified into less loud PTFE film group (groupI) and loud PTFE film group (groupII). Loudness(Z) was higher when staple yarn was used compared when filament yarn was used. According to the correlation between the mechanical properties of fabrics and loudness(Z) in groupI, the shear properties, compression properties and weight showed positive correlation with loudness(Z). According to the regression equation predicting loudness(Z) of groupI, the layer variable was chosen. In groupII, variables explaining the loudness(Z) were yarn types and shear hysteresis(2HG5).

• Journal of Korea Water Resources Association
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• v.53 no.12
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• pp.1097-1107
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• 2020

A methodology has been proposed to understand the spatiotemporal changes of the river topography through the longitudinal change of the geometric characteristics of the cross-sections and the properties related thereto. Three-dimensional spatial information of the riverbed was obtained through the detailed bathymetry survey using an acoustic echo sounder for the reach from Gumi Weir to Chilgok Weir in the Nakdong river. Geometric informations for the reference sections were extracted using the acquired bathymetry survey data. By comparing the geometric properties for the reference sections, it was possible to catch the topographic characteristics and its changes over a reach of the channel. Through comparison with past survey data, it was also possible to quantitatively grasp the amount of change in cross-sectional area and volumetric change of riverbed. It is expected that a quantitative evaluation of river topography changes will be possible by applying the method proposed in this study.