• Elastomers and Composites
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• 제46권1호
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• pp.10-21
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• 2011

최근 자동차 산업의 발전과 더불어 수요자의 요구가 다양화, 고급화됨에 따라 차량의 흡/차음에 대한 관심이 크게 증가하고 있다. 일반적으로 차내의 소음과 진동을 줄일 수 있도록 하기 위하여 섬유재료(펠트, 유리섬유), 폴리우레탄 foam, PET 섬유재료 등과 같은 소음진동 흡수재료를 사용되고 있다. 이러한 소음 진동을 위한 흡/차음재료들은 자동차에 장착되어 다양한 부분에서 발생하는 소음 및 진동을 차단하여 쾌적한 승차감을 주는 주요한 부품으로 자리잡고 있다. 또한, 차량의 소음 진동 제거를 위한 자동차용 흡/차음재료의 요구는 최근들어 더욱 높아지고 있으며 소음 진동 저감 이외에 연비개선을 위한 경량화, 비용절감 등도 함께 고려되고 있다. 따라서 본고에서는 자동차 내장 흡/차음재료의 필요성과 더불어 관련기술에 대하여 중심으로 살펴보도록 하겠다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 추계학술대회 논문집
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• pp.463-464
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• 2009

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.883-888
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• 2002

This study describes the limit and application of the two-microphone impedance tube method to the sound transmission loss measurement of several sound isolation materials with different physical properties. For the sound isolation materials having small flexural rigidity, it is shown that the two-microphone impedance tube method is validated to practically measure the sound transmission loss. For the sound isolation materials having large flexural rigidity, on the other hand, it is found that the two-microphone impedance tube method is no longer valid to measure the sound transmission loss because the regions of resonance and mass law are moved into the higher frequencies. In addition, in order to accurately measure the sound transmission loss of sound isolation materials, their size should be decided based on the consideration of the effect of acoustic excitation on their vibration response.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.141-146
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• 2007

A gear whine sound due to the axle system is one of the most important sound qualities in a sport utility vehicle (SUV). In the previous research about the gear whine sound, it was known that it is difficult to evaluate the gear whine sound objectively by using the only A-weighted sound pressure level because of the masking effect. In this paper, for the objective evaluation of the axle-gear whine sound, the characteristics of the axle-gear whine sound is at the first investigated based on the synthetic sound technology and the new objective evaluation method for the axle-gear whine sound is developed by using the sound metrics, which is the psychoacoustics parameters, and the artificial neural network (ANN) used for the modeling of the correlation between objective evaluation and subjective evaluation.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.519-524
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• 2013

The purpose of this study is that developing the index which evaluate sound quality of door latch and improving its sound quality through that results. For that, various operating sound of door latch was used for jury test. Loudness and sharpness related metrics are dominant in sound quality index we developed. This research investigate the main transfer path of its operating sound through sound field visualization and get conclusion that could reduce the impact sound of door latch. Therefore, we could verify sound quality improvement of modified product by using sound quality index.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.385-388
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• 2005

Finite element method and Taguchi method were used to reduce the floor impact vibration of the reinforced concrete slab in the apartment buildings. At first, experimental results show that sound peak components to influence the rating of floor impact sound insulation were coincident with natural frequencies of the reinforced concrete slab, and there is a high linear relation between floor impact vibration and sound. The tables of orthogonal arrays were used for finite element analysis with 5 factors related to slab shape parameters and its results were analyzed by statistical method. The most effective factor to reduce the floor impact vibration was the length of living/kitchen room and the floor impact vibration was predicted by 30% reduction in the acceleration peak by the optimal design values of the factors.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.1187-1190
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• 2007

This study aims to induce acoustic environmental characteristics which could be used for soundscape design by carrying out factor analysis on sound source image and cognition analysis on subjects' responses on selective questions due to class differences. The results of this study are as follows ; Satisfaction rate differences on exterior acoustic environment due to sensitivity and residence year were revealed. After factor analysis of living sound sources' image, it is known that natural sound, traditional sound, socials traffic sound, rural sound, religious sound and the others are main factors. Social traffic sound is the most one that should be eliminated and traditional sound is selected as a most Korean-like sound. Natural sound is evaluated as the most one that should be preserved and the most retrospectively one.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.377-382
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• 2003

In our previous study, we have developed sound quality index for steady rumbling sound of passenger car. In this paper, we will study sound quality index for transient rumbling noise. The subjective evaluation of rumbling sound can be indicated to objective parameters by sound metrics of psychoacoustics and principal rumble component. And artificial neural network can be estimated complexity and nonlinear characteristics of relation between subjective evaluation and sound metrics. We applied to sound metrics and artificial neural network to development of sound quality index for transient rumbling sound of passenger car.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.849-854
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• 2001

A study on performance of the sound absorbing noise barrier is presented. Noise barrier of sound absorbing type is composed of the front panel, sound absorbing material, and back panel. For allowing sound path, front panel is usually perforated. The performance of the noise barrier is governed by the opening ratio of the perforated panel, sound absorption coefficient of the sound absorbing material. In this study, the effects of the opening ratio, diameter of the hole, thickness of the sound absorbing material are investigated. It is found that the thickness of the sound absorbing material must be at least 50 mm to ensure the required minimum NRC value 0.70, and the opening ratio is greater than 0.2. It is shown that the thickness of the back panel is crucial in providing required STL (Sound Transmission Loss) value. The performance of the developed noise barrier is measured, where its sound absorbing coefficient and sound transmission loss satisfy the criteria.

• 한국소음진동공학회논문집
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• 제13권6호
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• pp.445-451
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• 2003

Booming sound is one of the most important interior sound of a passenger car. The conventional booming noise research was focused on the reduction of the A-weighted sound pressure level. However A-weighted sound pressure level cannot give the whole story about the booming sound of a passenger car. In this paper, we employed sound metrics, which are the subjective parameters, used in psycoacoustics. According to recent research results. the relation between sound metrics and subjective evaluation is very complex and has nonlinear characteristics. In order to estimate this nonlinear relationship, artificial neural network theory has been applied to derivation of sound quality index for booming sound of a passenger car.