• Journal of the Korean Society of Clothing and Textiles
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• v.47 no.1
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• pp.110-122
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• 2023

The COVID-19 pandemic increased people's time at home and caused an 80% increase in noise disputes between floors. The purpose of this study is to propose suitable materials for making indoor shoes (insoles) to minimize noise between floors. Subjects without back pain and leg-related disease (e.g. arthritis, etc.) from three different age groups (childhood, adolescence, and adulthood) were recruited for the study. Five polymer insole materials were considered: Chloroprene Rubber (CR foam), Ethylene Propylene Diene Monomer (EPDM foam), Natural Latex foam, Ethylene Vinyl Acetate (EVA foam), and Polyurethane (PU foam). From these materials, 20 combinations were prepared and randomly tested for noise and vibration. The results revealed a significant difference in noise and vibration levels based on the type of material used and the age of the subject. Nevertheless, all materials under consideration successfully reduced noise and vibration; in particular, type A-C greatly decreased. The CR foam material was especially effective at noise and vibration reduction (p<.01). This study suggests that adding insoles into socks that children wear at home could reduce noise vibration and disputes between floors.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.356-360
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• 2006

Recently, for the purpose of improving the isolation performance of impact noise, many resilient materials have been installed in a residential building. As one of the reduction method for improving the performance of light-weight impact noise, this study is focused on the load condition of floating layer over resilient material. We studied the correlation between the mass or load of the floating layer and the reduction of light-weight impact noise by experiments in reverberation chamber for testing the impact noise. The results show that the reduction of impact noise is improved by increasing the mass per unit area of floating layer until about $140kg/m^2$. But the reduction is not obvious by adding extra mass on the floating layer.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.6
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• pp.620-627
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• 2023

Ship noise is one of the important factors for the living and health of seafarers, and ef orts to reduce ship noise are actively underway. There are two methods of noise reduction: passive noise Control (PNC) and active noise control (ANC). Unlike cars and airplanes, ANC is not widely used for noise reduction on ships. This study aimed to reduce the noise generated in the engine room by using soundproof panels and high-frequency vibration generators, as well as active noise control (ANC). For this purpose, an experimental model was made using an acrylic box, and the noise reduction effect was measured under four conditions. The experimental results are as follows: First, the soundproof panel had a noise reduction effect in all ranges from 55 dB to 85 dB. In the case of using a high-frequency vibration generator, there was no ef ect in the low noise range such as 55 dB(A), but there was a noise reduction effect in the high noise range such as 70.8 dB(A) and 85 dB(A).Second, when the soundproof panel and the high-frequency vibration generator were used simultaneously, the noise reduction ef ect was up to -2.2 dB(A). The results of this experiment were obtained from an experimental model made of acrylic, and they may be different from actual ships made of steel plate. In future studies, we plan to experiment using iron plate (considering the material, thickness, and structure) used in actual ships. We hope that this study will help to improve the living environment and health of seafarers on ships.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.923-927
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• 2003

The aim of this study is to investigate the characteristics and quantity of the noise reduction by pipe material, wrapped pipe with glass wool and installed pipe height The characteristics of noise emission from drain-pipes is as follows. The noise reduction pipe in PVC can reduce noise levels in 7-10㏈ and the cast-iron pipe can reduce in 14㏈compared with the normal PVC pipe. In these days, the glass wool was used for preventing the burst and the noise reduction. But the glass wool for wrapping pipe is not effective to the noise reduction. The characteristics of noise emission from various installed pipe height were measured As the ceiling space of the remodeled building was raised, the noise level was troubled by increasing of the vertical pipe length.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.691-692
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• 2012

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.127-132
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• 2001

A successful design approach for noise barriers should be multidisciplinary because noise reduction goals influence both acoustical and non-acoustical considerations, such as maintenance, safety, physical construction, cost, and visual impact. These various barrier design options are closely related with barrier dimensions. In this study, we have proposed an optimal design method of straight noise barriers using genetic algorithm, providing a barrier having the smallest dimension and achieving the specified noise reduction at a receiver region exposed to the industry and traffic noise, to help a successful barrier design.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1998.04a
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• pp.510-515
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• 1998

Most of large structures such as ship, airplane, and so on have internal structure home noise sources. The operation of the machineries results in vibration and noise of the structure. Particularly, the vibration of the machineries is transmitted to the far place from the sources and emits noise into the water or outdoor as well as the inner space of the structure. In the case of warships this emission into the water induces noise to reduce the performance of its underwater acoustic equipment. Therefore the structure home noise levels of the installed machineries are strictly limited. This paper shows examples of structure home noise reduction from machineries including pumps.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.109-112
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• 2005

Since 1989, when the first European noise regulation against construction equipments came into force, much investigation had been devoted to reduce the noise and had produced the remarkable improvement in noise reduction technology. EU Directive 2000/14/EC Stage 2, more stringent noise regulation, is going to be implemented from Jan. 2006. The technology trends and examples for noise reduction in typical construction equipment R&D is described briefly.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.449-452
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• 2005

This paper introduces a study for the noise reduction of a range hood for household. Generally, range hoods have a built-in sirocco fan from which squawky noises are generated. Though the squawky noises have low noise level, these kinds of noises make most of the users nervous. For the purpose of noise reduction, in this study, a perforated plate system is installed in the fan housing of range hood. From the experimental results, it is confirmed that the noise level omitted front the range hood is decreased above 2dB(A) in all frequency regions due to the effect of noise reduction by perforated panel system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.848-851
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• 2004

This paper studied a method for minimizing the noise level emitted from range hoods. Range hoods were used for discharging various hazardous materials generated during household cooking to the outdoors, thus preventing them from being diffused through rooms in the house since they are the main cause of air pollution within dwellings. This study assumed that static pressure was not applied at the discharge outlet of the range hood. As such, the range hood was installed on the wall without the use of a connecting duct or other connectors attached to its discharge outlet. The vibration having the greatest influence on the noise level was determined by measuring the vibration at the front side of the hood where the acoustic omission was at its maximum. A method was then proposed to reduce the noise by simply suppressing the vibration at the vibrating part.