• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.1044-1047
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• 2004

This aim of this study is is an experimental study to introduce the Reduction method of Floor Impact Sound in Apartment Houses by using Model Test, We are measured the floor impact sound in Rahamen and Apartment with Shear Wall and Post-tensioning. There is comparison between Rahmen Structure and Apartment with Shear Wall. The main results from this study are effective in reduction of heavt-weight The slab was constructed by rahamen structure. Heavy-weight can reduced by upgrading naturial frequency of floor impact sound in rahmen structure.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.671-674
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• 2006

Heavy-weight impact sounds generated by impact ball were classified according to the frequency characteristics on the equal loudness contours. Sound quality metrics such as Zwicker's loudness, sharpness, roughness of each classified impact sound were also measured. Loudness spectrum has been regarded as an indication of the characteristics difference of each classified impact sound. The adjectives in Korean expressing the sound quality characteristics of floor impact sounds were also investigated by adoptability and similarity tests. The group of the adjectives was used to evaluate the sound quality of floor impact sound by semantic differential test method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.839-843
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• 2008

Receiving room's floor impact sound level is been influenced to various factor of slab thickness, room size, structure etc. This study examined the noise of upper part slab and room mode in receiving room to be importance factor that influence in receiving room level among this factors. According to this study, vibration mode in slab and room mode are concentrated on frequency that is high level relatively. This causes bad effect in floor impact sound level. Therefore, method to reduce floor impact sound level is to change vibration mode using slab upper part's resilient material or reduce room mode in receiving room.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.969-973
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• 2007

The heavy-weight floor impact sound field of the receiving room in a testing building with bearing wall structure was investigated using bang machine and impact ball. The sound field was investigated through the impact sound pressure level distribution by the field measurement and computational analysis. Predicted sound field using the computational analysis agree with measurement result in the low frequency band. Result shows that standard deviations of the single number rating value are about 2dB in each impact source. Particularly, impact sound pressure level at 120cm height in 63Hz octave band was 5dB lower than spatial averaging value. It was found that receiving positions in the ministry of construction and transportation notice should be reconsidered.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.262-265
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• 2006

In order to investigate characteristics of floor impact sound generated in the apartment buildings, questionnaire survey was conducted for respondents living in apartments in 200t. Questions in the surrey were on the characteristics of real impact sounds, subjective annoyance and satisfaction on the heavy and light impact sources. From the survey results, it was found that most annoying time of a day and the space were 8 p.m. to midnight at living room. It was also revealed that the main source of the floor impact sound from the upper floor is a child's jumping and running at from six to nine. More than half of people were not satisfied on the floor impact isolation performance of their own apartments. The percentage of residents who were annoyed by the heavy-weight impact sound such as children's jumping and adult's walking was $5{\sim}10%$ lower than by light-weight impact sound. In addition, females being responded more annoyed by floor impact sound than males.

• Journal of the Korean Wood Science and Technology
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• v.51 no.5
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• pp.419-430
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• 2023

In this study, the floor impact sound insulation performance of Korean domestic Cross-Laminated Timber (CLT) slabs was evaluated according to their joint types, species and thicknesses in laboratory experiments. The sound insulation performance of the CLT has not been investigated before, thus, this study was conducted to quantify basic data on floor impact sound insulation performance of CLT slabs. 5-ply and 150 mm thick CLT panels made of 2 species, Larix kaempferi and Pinus densiflora, were used for the study. The CLT panels were assembled by 3 types of inter-panel joints to form floor slabs: spline, butt and half-lap. And the 150 mm thick Larix CLT slabs were stacked to the thicknesses of 300 mm and 450 mm. The heavy-weight floor impact sound insulation performance of the 150 mm CLT slabs were evaluated to be 70 dB for the Larix slabs and 71.6 dB for the Pinus slabs, and the light-weight floor impact sound insulation performance, 78.3 dB and 79.6 dB, respectively. No significant difference in the sound insulation performance was found between the slabs of the 2 species or among the 3 types of joints. The reduction of 1 dB in the heavy-weight floor impact sound and 1.6 dB in the light-weight floor impact sound per 30 mm increase in thickness were confirmed through the experiments. This study can be viewed as the basic research for the evaluation of floor impact sound insulation performance of CLT.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.7
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• pp.651-657
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• 2010

Previous experimental results performed by many researchers for a couple of decades in South Korea have shown that an absorbing sheet inserted in a conventional floating slab system for thermal insulation or vibration absorption may amplify the vibration of the slab system at specific frequency ranges depending on the material properties of the sheet. The amplified vibration, consequently, results in the heavy weight floor impact noise exceeding the sound level limit for an apartment house, 50 dB. In this study, the amplification mechanism is examined through numerical analysis and a new slab system is proposed to reduce the amplification and control the noise. The new slab system consists of studs connecting the base slab and upper concrete finishing yielding the dramatically increased stiffness of the slab. The numerical simulation is performed to investigate the effect of the slab system with studs on the vibration and noise control. The results show that the performance of the slab is sensitive to the number and location of studs, and the heavy weight floor impact noise can be reduced up to 6~7 dB compared to the conventional slab system at the optimal stud location.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.394-402
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• 2009

To investigate the heavy-weight impact noise of apartment houses, numerical analysis was performed. The analysis acoustic pressure consider acoustic mode by finite element method. The variables considered effecting on the acoustic pressure are the Acoustic mode, acoustic damping, and the impulse load. The heavy-weight impact noise is a changeable value in the room. Since the most part of the frequency component of heavy-weight impact noise has low frequency. The noise in low frequency is related to the vibration of structure, the reflection of acoustic wave caused by wall and the standing wave called by acoustic mode. The prediction by the numerical analysis was verified with test result of the heavy weight-impact noise at apartment houses.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.7
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• pp.501-508
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• 2014

Floor finishing materials such as floor coverings and floor mats can reduce floor impact noise easily. When an impact was applied to the floor, its finishing material is deformed and the impact force that was applied to the concrete slab is changed. The softer finishing materials were, the more impact force decreased. An experimental study was performed using 14 PVC floor coverings and 16 floor mats to capture the characteristics of impact force and impact noise in the residential buildings. The test results show that the impact force spectrum and the floor impact noise spectrum have a linear relationship in the case of a bare concrete slab, and the characteristics of impact force reduction are the same as those of floor impact noise reduction.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.390-393
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• 2005

In this study, examined heavy-weight floor impact sound to rahmen structure(steel reinforced concrete structure) and bearing-wall structure(box frame type structure) that have slab thickness of 4 form at a standard laboratory through noise and vibration measured. The results of ANSYS modeling of structures was predicted that the nature natural frequency increased according to change of thickness of each slab by finite element analysis, and acceleration value decreased. Rahmen structures compares with bearing-wall structure, nature frequency was predicted low. Measurement results of natural frequency and acceleration level for structures at a standard laboratory, tendency department such as ANSYS modeling appeared. Rahmen structures appeared that reduction effect is less in Acceleration level and heavy impact sound transmission level comparing with bearing-wall structure.