• Journal of the Korean housing association
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• v.10 no.2
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• pp.203-212
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• 1999

The purpose of this study is to evaluate the Korean residents' subjective opinion of the noise on the lowrise multifamily house in America. The results of this study can be applied for the prevention of noise when planning cities, roads, and multifamily houses in Korea. The subjects of this study are three kinds of multifamily houses and their 124 Korean residents in Athens, America. The results of this study are as follows. The Korean residents felt the noise from lawn mowers and the sound of filter fan of air conditioners were higher than all the other external noise. They were disturbed a little by the external noise. The air borne sound was recognized a little by Korean residents but they only felt moderate sound of building services and household equipment from the solid borne sound of the internal noise. They suffered worse from external noise in the summer and they felt worse from 8～12 o'clock due to external noise and 20～24 o'clock due to internal noise. The Korean residents liked the sound of birds or insects, the sound of cars and trains. However many Korean people in Athens disliked the sounds of birds or insects and lawn mowers more than these sounds in Korea. The Korean residents who were living in the apartment houses felt better than those in the other multifamily houses.

• Journal of the Korean Society for Railway
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• v.2 no.3
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• pp.18-25
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• 1999

A high speed train named Korean High Speed Train (KHST) with its maximum operating speed 350 km/h is now under development. For the successful design of a quiet and comfortable high speed train, it is important to understand the general features of the noise and vibration characteristics of high speed train. This paper reviews extensively collected materials on the noise and vibration characteristics of existing high speed trains. Based on the noise and vibration characteristics of TGV systems, a simple indoor-noise prediction rule is proposed for the TGV-type high speed trains such as KHST The indoor-noise of KHST at 350km/h is expected to be larger than at least 71 dBA. Some important researches conducted for designing KHST during last two years under the G-7 project are also briefly introduced at the last part of this paper.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.365-370
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• 2011

Structure-bone noise is an important aspect to consider during the design and development of a vehicle. Reduction of structure-bone noise of the compartment in a vehicle is an important task in automotive engineering. Many methods which analyze transfer path of noise have been used for structure-bone noise. The existing method to measure of frequency response function of transfer path has been tested by removing a source. This Paper presents an experimental analysis about Transfer Path Analysis of the vehicle interior noise according to Excitation or not. To identify these points of difference, experiment were conducted through an experimental test using simulation vehicle.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.215-217
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• 2008

This paper deals with the structural vibration characteristics for an outdoor units support of an air-conditioner. Even though main noise sources are compressor noise and fluid noise which is caused by the fan, the structural modification of the outdoor units support may affect vibration and noise. In this paper, damping ratios for two kinds of an outdoor units support of an air-conditioner are measured through the modal testing. In order to reduce the structural borne noise due to an outdoor units support of an air-conditioner, four kinds of rubber materials are selected and tested.

• The Journal of the Acoustical Society of Korea
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• v.10 no.2
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• pp.78-84
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• 1991

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.361-364
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• 2011

In this paper, This work demonstrates a experimental evaluation for vehicle road noise NVH performance from the component-level NVH measurements of Tire. The power unit noise from tire emitted by cars has been reduced. It has been found that tire noise dominates noise produced by the power train when vehicles are driven at high constant speed. Therefore tire pattern noise is affected by pattern and vehicle and transmission loss. Tire noise mechanism is generated by several mechanisms. The sound of tire can propagate either through the air or through the structure of vehicle. Pattern noise is the result of pressure variations through the air to the interior side of vehicle. Especially, smooth asphalt, the periodicity of tread design, groove depth is important factor, which have an influence on the reduction of tire pattern noise.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.54-60
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• 2006

This study looks over the relation between propeller and noise in ship stern structure. Near field noise and vibration measurements are compared with the analytical results using wave number method. To avoid singularity in wave number integration method, fast field method is introduced. Analytical results show that main transmission mechanism of high frequency noise is structure-borne type and that of low frequency noise is a air-borne type.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.1
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• pp.22-28
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• 2012

While a dash panel component, close to passengers, plays a very important role to protect heat and noise from a power train, it is also a main path that transfers vibration energy and eventually radiates acoustic noise into the cavity. Therefore, it is important to provide optimal design schemes incorporating sound packages such as a dash isolation pad and a floor carpet, as well as structures. The present study is the extension of the previous investigation how design variables affect sound radiation, which was carried out using the simple plate and framed system. A novel FE-SEA hybrid simulation model is used for this study. The system taken into account is a dash panel component of a sedan vehicle, which includes front pillars, front side members, a dash panel and corresponding sound packages. Design variables such as panel thicknesses and sound packages are investigated how they are related to two main NVH indexes, sound radiation power(i.e. structure-borne) and sound transmission loss(i.e. air borne). In the viewpoint of obtaining better NVH performance, it is shown that these two indexes do not always result in same tendencies of improvement, which suggests that they should be dealt with independently and are also dependent on frequency regions.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1405-1409
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• 2000

The electro-magnetic noise generated from fan-driving motor is one of important items in view of abnormal noise which affect the quality of air conditioner noise. The electro-magnetic noise of the outdoor unit is identified by the serial experiments for related parts, whose effects are verified to give proper measures for reduced noise level. The weight of fan appears to be the most important factor, and the stiffness of the frame, such as motor bracket is shown to be important also.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.1081-1085
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• 2002

A modeling is developed to predict the isolation performance of sound barrier systems under the sound pressure radiated from excited by point impact. The predicted results are compared with the measured results obtained by using APAMAT II. This instrument provides a combination of structure-borne noise and air-borne noise, which corresponds to rolling noise, by applying the excitation system projected steel balls against the steel sheet.