• Journal of KSNVE
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• v.10 no.1
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• pp.82-96
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• 2000

The purpose of this study is to figure out the relationship between the mini-laboratory and the reverberation room for the domestic floor structures which are practically constructed in apartment houses. For this purpose, seven specimen which were varied in structures and thicknesses were tested in Chonnam National University reverberation room and in the artificial mini-laboratory which is the $\farc{1}{3}$ scale model of the former. From the result of this study, it was proved that there is a good correlation between the mini-laboratory and the reverberation room for the apartment floor structures as well as floorcovering PVC. The result of this study could save the labor and the time, etc.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.8
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• pp.651-658
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• 2014

Notification 2013-611 of MOLIT has come into effect. It relates primarily to new standard impact source. In this study, an in-depth experimental analysis of the difference between a bang machine and an impact ball was performed via field testing of shear wall and flat plate structure at 51 sites. This paper focuses on the difference in single number quantities between a bang machine and an impact ball. At wall thicknesses of 180 and 210 mm in shear wall structure, the single number quantities exhibited differences of 3.1 and 4.5 dB, respectively, and at thicknesses exceeding 250 mm in flat plate structure, the difference was constant at 4.6 dB. With regard to flat plate structures, the single-index difference increased up to 11 dB as the thickness of the floor slab increased. In general, the highest level of contribution for the bang machine was 63 Hz, irrespective of thickness determining bandwidth. The highest level for the impact ball were 63 Hz and 125 Hz. In future research, when reviewing additional field performance measurement data, it will be necessary to consider a detailed examination instead of the current method of uniformly adding 3 dB for all thicknesses and types of structures.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.3
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• pp.274-281
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• 2013

Field measurement method of heavy/soft impact sound pressure level which is regulated in JIS and ISO has been using in Korea, Japan and Canada. It is reported that heavy/soft impact sound pressure level was varied by the sound field condition of receiving room such as sound absorption power and room volume. In this study, it is checked that heavy/soft impact sound pressure level was affected by the receiving sound field condition. Rubber ball and bang machine sound pressure level was measured in the vertically connected reverberation chamber. In oder to check the effect of receiving sound field on heavy/soft impact sound pressure, sound absorption power was changed with polyester sound absorption blankets with air space and glass wool. The reverberation time at 1 kHz band was changed from 10 s to 0.2 s by sound absorption material. Rubber ball sound pressure level measured without sound absorption material was 58 dB in $L_{i,Fmax,AW}$, but the level was 46 dB with sound absorption treatment. From this result, it is confirmed that sound field correction method is needed in the heavy/soft impact sound pressure level measurement method using bang machine and rubber ball.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.800-803
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• 2005

Impact sounds, such as those created by footsteps, the dropping of an object or the moving of furniture, can be a source of great annoyance in residential buildings. Running and jumping impact sound by child and walking by adult are one of the most irritating noises in an apartment buildings. It's necessary to know that the impact power characteristics of real impact source in an apartment buildings. This study aims to investigate the impact power and impact time of normal walking and fast walking for 62 adults. It is shown that when the weight of the person increase, the maximum impact power increases. The impact power waveform for the adults walking varies for subjects walking types. The normal walking impact power lower than that of fast walking and impact time is higher than that of fast walking. The range of the impact power generated by adults walking is less than 1000 N.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.586-591
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• 2002

Recently, the research and discussion to set up the evaluation standard for nor impact noises in multistory residential buildings has been vividly carried out In Korea. Therefore, the correlation between the methods and auditory responses was investigated through this research to investigate the applicability of the L index evaluation method and the reverse A characteristics evaluation method that are listed in JIS A 1419 since Japanese circumstance are similar to Korean after evaluating the duality of Korean multistory residential buildings. As a result, it was found that the correlation between the value resulted from L index evaluation and the value from reverse A characteristics evaluation is high. In addition, it was also revealed that human responses to each Impacter was similar. Consequently, it is considered th:31 the tendency about the two methods would be similar.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.1187-1192
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• 2003

The railroad noise has been considered as one of environment pollution and complaints about it have been increasing every you. Therefore, the establishment of railroad noise monitoring network is necessary. It will be designed for monitoring railroad noise, storing data of railroad noise continuously and providing the fundamental knowledge for the measures of railroad noise. For this, we investigated the actual condition of railroad noise and status of noise level by floor in apartments around the capital region, Daejeon, Daegu, Gwangju, and Busan. Additionally, we present the basic data that will be used for predicting the noise level near railroad in the environmental impact assessment

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.2 s.107
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• pp.149-155
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• 2006

There are various types of noise around us such as road traffic noise, aircraft noise and floor impact sound, equipment noise, etc. Researches on the noise criteria and the evaluation method for the diffuser noise of HVAC are insufficient. dB(A) and NC values represented in ASHRAE guide book are applied as a noise criteria for diffuser noise, which have some problems like that the values between dB(A) and NC have deviation even if the sound is same one. Therefore, the evaluation method should be considered and proposed based on the subjective responses. From these reasons, this study aimed to analyze the evaluation factors for the diffuser noise of HVAC reflected on the subjective responses by surveying vocabularies and grouping them with factor analysis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.349-354
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• 2005

There are various types of noise around us such as road traffic noise, aircraft noise and floor impact sound, equipment noise etc. Recently researches on the criteria to evaluate the noises have been progressed, however, researches on the noise criteria and evaluation method for the diffuser noise of HVAC are insufficient. dB(A) and NC values represented in ASHRAE guide book are applied as a noise criteria for diffuser noise, which have some problems like that the values between dB(A) and NC have deviation even if the sound is same one. Therefore, the evaluation method should be considered and proposed based on the subjective responses. From these reasons, this study aimed to analyze the evaluation factors for the diffuser noise of HVAC reflected on the subjective responses by surveying vocabularies and grouping them with factor analysis.

• Magazine of RCR
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• v.10 no.4
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• pp.57-64
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• 2015

• Journal of KSNVE
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• v.11 no.3
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• pp.443-448
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• 2001

The subjective unwantedness felt from the noise sources in living environment has been evaluated by investigating the limit of perceptual loudness of the noise. The noise limits were selected by the subjects. And the noises were analyzed to find out whether there is any correlation with Zwicker parameters and ACF/IACF factors. It seemed that the loudness of noise from vacuum cleaner does not affect its perceives noisiness. Traffic noise also seems to be less influential in annoyance rating. It was resealed that floor impact noise generated by bang machine is the most irritating noise that can be heard in residential buildings.