• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.220-222
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• 2008

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.678-679
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• 2010

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.8
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• pp.802-808
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• 2009

In this paper, the experimental study on the identification of noise sources and noise transmission paths was carried out for the cabin noise control of construction equipment. In order to investigate noise and vibration characteristics of cabin structure, sound absorption, transmission, and radiation tests were performed using cabin assembly models. The noise/vibration source levels were obtained from the real cabins of wheel loader and excavator. Using transfer functions of cabins and real cabins' source data, cabin noise was decomposed into airborne and structureborne noise transmissions. Finally noise sources and major transmission paths were successfully identified for wheel loader and excavator's cabins.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.667-672
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• 2007

The source of wayside noise for the train are the aerodynamic noise, wheel/rail noise, and power unit noise. The major source of railway noise is the wheel/rail noise caused by the interaction between the wheels and rails. The Structure borne noise is mainly a low frequency problem. The train noise and vibration nearby the elevated railway make one specific issue. In this paper, the train noise and structure borne noise by train are measured. From the results, we investigated the effect on the sound absorption tunnel for elevated railway.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.84-89
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• 2009

In this paper, the experimental study on the identification of noise sources and noise transmission paths was carried out for the cabin noise control of construction equipment. In order to investigate noise and vibration characteristics of cabin structure, sound absorption, transmission, and radiation tests were performed using cabin assembly models. The noise/vibration source levels were obtained from the real cabins of wheel loader and excavator. Using transfer functions of cabins and real cabins' source data, cabin noise was decomposed into airborne and structureborne noise transmissions. Finally noise sources and major transmission paths were successfully identified for wheel loader and excavator's cabins.

• Journal of the korean Society of Automotive Engineers
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• v.8 no.4
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• pp.43-55
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• 1986

In the studies of noise reduction, it is important to know the generation mechanism of noise in order to identify the noise source. The relation between the structural vibration and the radiated sound is very complex and so this paper deals with a simplified radiation model that was originally developed as a verification tool for the acoustic intensity measurement procedure. As the first step for the identification of the noise source, this study deals with the noise evaluation by measuring sound pressure. On the next step, the acoustic radiational pattern is determined by the acoustic intensity method and this paper established that the acoustic intensity method is effective on the detection of noise. In the study, furthermore, the method could be used to predict the change in the sound radiational characteristics with the attachment of absorber and could be used in determining the attachment position.

• Journal of the Society of Naval Architects of Korea
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• v.28 no.2
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• pp.268-274
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• 1991

The methods of prelimiuary noose prediction by Janssen, Buiten, etc are introduced. The distribution of noise levels in newly built ships are investigated. A new procedure for noise prediction is proposed which reflects the results of the investigations. The dominant noise souroes(M/E, D/G) are regarded as one virtual source. The structureborne transmission loss are divided into vortical and horizontal components and the latter component depends on the number of decks as well as the number of frames. The all considered cabins are standardized with typical cabins which have the same acoustic properties. The measured and predicted noise levels are compared In the tables.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.596-599
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• 2008

Traditionally, tire made a role of function, which is supporting vehicle load, making brake, transferring traction, etc. But tire is a part of vehicle design, nowadays. In accordance with this market trend, customers need a wide tread design tire (i.e. low series tire). Generally low Series Tire means stiffer than general tire. That brings out increasing road noise. (Especially tire cavity resonance noise) Tire noise is divided in structure home noise and air borne noise. Tire cavity resonance noise (structure home noise) come from vibration between tire and vehicle. In the study, we investigated that tire cavity resonance noise is affected by stiffness of tread and sidewall.

• Transactions of the Korean Society of Automotive Engineers
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• v.1 no.1
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• pp.110-119
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• 1993

본 논문은 자동변속기를 탑재한 차량에서 에어콘(air condition)을 작동시키고, 공 회전시 기어의 변속을 "D"단에 두었을 때 실내에서 발생하는 이상음의 원인규명 및 해결 방 법에 관한 연구 결과를 논하고자 한다. 이 이상한 소음의 원인을 규명하기 위하여 실린더 내부의 연소압력, 메인 베어링캡(main bearing cap)의 진동, 엔진 마운팅 보스의 진동 및 차 량의 실내소음을 동시에 측정하여 분석하였으며 이 결과에 의하면 이상음의 원인은 크랭크 샤프트(crank shaft)의 굽힘진동이 파워플랜트(power plant)를 가진하여 진동을 증가시키고, 이 진동이 마운팅 보스를 통하여 차량의 차체에 전달되며, 차체의 진동에 의해서 발생하는 고체 전달음(structure-borne noise)이었다. 또한 이상음의 주기는 주파수 성분은 200-400Hz 이었다. 이 이상음은 크랭크 샤프트의 댐퍼 풀리의 질량을 저감하여 크랭크 샤프트의 동특 성을 개선함으로서 해결가능하고, 혹은 점화시기를 지연하여 연소 압력을 낮춤으로서 해결 가능하다.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.6
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• pp.91-96
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• 2008

As a remarkable reduction of the vehicle noise, the important of tire noise which is generated from the vehicle and the necessity of the research for the noise reduction is being emphasized. In this study, the road noise which is excited by the interaction between tire and road has been studied. The subjective test(feeling test) according to SAE J1060 rating scale is applied to the evaluation of the road noise. The combination of the several tires and vehicles are made to consider the effect of the vehicle suspension and the tire structure for road noise. The vehicles with 3-different suspension system are applied to road noise test and the eight kinds of tires are selected. As the results, the effects of the vehicle suspension and tire structure which affects on road noise are investigated.