• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.579-585
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• 2002

This study has measured and evaluated the sound insulation of building elements of the hotel near airport. That measurement was made in both the actual site and laboratory. The differences of sound insulation performance in between granite and double glass were measured. Moreover, the difference of sound insulation was analyzed. For the measurement, this study has tried several methodologies, and analyzed the differences respectively. The results from this analysis were applied to produce a design guides for sound insulation to prevent external noise and to make more silent indoor space which satisfied the standard rate of noise.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.457-460
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• 2004

This study examines the sound insulation of the light-weight wall using light-weight concrete and offers the basic datum for enhancing it. The sound insulation of the light-weight wall is determinated by the density, installation method, absorption materials, air layers etc. Among the factors, the solution of outlet that is the major cause of reducing sound insulation should be made. If absorption materials are installed in the cavity walls, it enhances to 15dB in 500Hz.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.976-979
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• 2004

The KS of 'Laboratory Measurement of Impact Sound Insulation of Floors' is not established yet. To establish this KS, present conditions of domestic laboratory test facilities for measuring impact sound insulation of floors in laboratory and current researches were reviewed As a result the outline of 'Laboratory Measurement of Impact Sound Insulation of Floors' is suggested.

• Journal of the Korean Wood Science and Technology
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• v.30 no.3
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• pp.75-84
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• 2002

In order to find out impact insulation properties, various types of current radiant floor heating systems and light-framed floors that are used in light-framed residential buildings were evaluated for two types of impact sources at the same time. Sound Pressure Level (SPL) was different from each impact sources for those spectrum patterns and peaks. In case of light-framed floor framework, the excitation position and the assumed effective vibrating area have effects on sound pressure level but it is not considerable, and Normalized SPL was reduced for each frequency by increasing the bending rigidity of joist. The mortar layer in the radiant heating system had relatively high density and high impedance, therefore, it distributed much of the impact power when it was excited, and reduced the Normalized SPL considerably. Nevertheless, Increasing a thickness of mortar layer had little influence on SPL. Ceiling components reduced the sound pressure level about 5~25 dB for each frequency. Namely, it had excellent sound insulation properties in a range from 200 to 4,000 Hz frequency for both heavy and lightweight impact sources. Also, there was a somewhat regular sound insulation pattern for each center frequency. The resilient channel reduced the SPL about 2~11 dB, irrelevant to impact source. Consequently, current radiant floor heating systems which were established in light-framed residential buildings have quite good impact sound insulation properties for both impact sources.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.10a
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• pp.222-226
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• 1997

The reproducibility of measured level is a prior condition for the reliable assessment of the sound insulation performance. To review the reproducibility of impact sound level, 20 floors were selected in highrise apartment house, and then impact sound levels of two kinds of typical floors were measured with 10 times in each receiving point. The impact sound insulation class values were derived with a standard tapping machine and bang machine. Inspection of the result showed that smaller scale of the room caused to lower the reproducibility and that the higher values of standard deviation in lower frequency caused to deteriorate the reliability of assesment. Thus to enhance the reproducibility of the impact sound insulation class, greater allowable deviation of measured level is required in lower frequency than in higher one.

• Journal of the Korean Wood Science and Technology
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• v.40 no.6
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• pp.431-444
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• 2012

Constituents of timber framed floor affect the insulation performance against impact sound significantly. Among them, installation of massive sound absorbing layer and reinforcement of stiffness of timber floor have been considered as major factors that improve the insulation performance against impact sound. Researches on evaluating the effect of floor constitutions have been carried out through the field measurements for timber framed buildings in Korea. It is concluded that the impact sound pressure level at the relatively lower frequency governs the overall insulation performance, and can be improved by the installation of sound absorbing layer and reinforcement of floor stiffness. Especially, the insulation performance against heavy impact sound was improved significantly when the massive cement mortar layer for floor heating system was installed and the stiffness was reinforced by shortening the joist span using additional beam at the mid-position of original span.

• Journal of the Korean Society for Railway
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• v.6 no.1
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• pp.10-14
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• 2003

Since most of main noise sources of the railroad vehicle are transmitted to the passenger's ear through the vibration of the panel, the sound insulation performance of the panels should be high enough to protect the passenger's ear from the noisy environment. Specifically, the composite materials which are generally used for reducing the weight of the vehicle compartment have the low insulation performance, thus noise control actions should be taken appropriately by considering the insulation performance of the panels. In this study, the insulation performances of the inner/outer panels of the compartment are evaluated. In addition, the contribution of the insulation performance of aluminum door is estimated and compared to those of composite panels. The results can furnish an in-depth understanding of the insulation characteristics of the panel of railroad vehicle.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.2
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• pp.92-99
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• 1998

The sound insulation capacity of honeycomb sandwich plates which have relatively higher strength ratios to weight is poorer than those of uniform and another sandwich plates. Therefore, improvement of the sound insulation capacity of the honeycomb sandwich plate which has a meritof lightness is required to use it in automobile and rapid rail road industries. In this study, to improving the sound insulation capacity of the honeycomb sandwich plate, the sound transmission loss of the structure is experimentally investigated by adding a viscoelastic damping layer, The effective add position and thickness of the layer were investigated from the viewpoints of both sound transmission loss and improved sound transmission loss over the frequency range from 800Hz to 10kHz.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.197-202
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• 2001

The compressor is one of major noise sources in air conditioner outdoor units, especially deteriorating the sound quality. Therefore, the sound insulation materials layered with sound absorption materials are applied around compressors. In this study, the performance of the sound insulators is examined by measuring the insertion losses in power base and the effects of sound absorption materials, method of application and the shape of the insulators are also investigated. The importance of minimizing the opening is revealed well.

• The Journal of the Acoustical Society of Korea
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• v.11 no.2
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• pp.50-58
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• 1992

To improve the quality of dwelling environment of domestic apartment house, it is required to establish the sound insulation standard and the performance evaluation method which is suitable to the domestic residential conditions. In this study, the properties of internal noisy sources of a single unit in apartment houses and the sound insulation performance of party walls are investigated and analyzed, as a primary step to the establishment of sound insulation standard. Based on these data, the differences in sound insulation index of each plane type are investigated along with their causes. Also, the factor which affect and decide the insulation performance are analyzed in an effort to improve the performance of party wall structures.