• 소음진동
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• 제8권1호
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• pp.112-121
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• 1998

In this report, Experimental analysis for main factors and analyzing methods of electro-magnetic noise and no loading noise was conducted because of noise of AC generator, which is peripheral equipment by reduction of engine noise that would be the main cause of vehicle radiation noise. In addition, This is intended to suggest the noise reduction development basis of AC generator for actual fan and electro-magnetic noise by making-analyzing-testing it's sample.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 추계학술대회논문집
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• pp.132-137
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• 2000

Recently, a severe noise problem was encountered during a shop test of large scale vertical motor. In order to identify the noise characteristics and propose the countermeasure, a variety of experiments such as sound excitation test and contribution analysis was earned out in addition to ordinary noise and vibration measurements. The results showed that the severe noise level was dominated by an acoustic resonance phenonmenon in the cooler housing and higher sound power of outer fan. Through proper treatments, the noise level could be acceptable.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.203-204
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• 2019

Recently, the number of conflicts and complaints related to noise between floors is increasing every year. It is essential to acquisition objective noise data in order to resolve legal disputes over floor noise. However, specialized equipment for noise acquisition is difficult for ordinary apartment dwellers to use. In addition, in order to solve the problem of inter-layer noise, it is most effective to locate and remove the noise. Therefore, this study proposes a floor noise monitoring system for the measurement of floor noise and estimation of the noise source that can be measured without a professional device.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.725-738
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• 2006

The final purpose of this study is to develop noise abatement procedures for minimizing damages caused by aircraft noise, to establish appropriate noise limits and to suggest a plan for imposing surcharges and penalties on aircraft infringing the noise limits. This study establishes noise abatement procedures and suggests a plan to complement and improve upon NMS in Gimpo International Airport by reviewing the NMS structure. In addition, this study establishes a noise limit at each noise monitoring system and a verification system to discriminate infringing aircraft. Finally, this study suggests a control plan for aircraft infringing the noise limit.

• 한국소음진동공학회논문집
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• 제17권5호
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• pp.379-390
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• 2007

The final purpose of this study is to develop noise abatement procedures for minimizing damages caused by aircraft noise, to establish appropriate noise limits and to suggest a plan for imposing surcharges and penalties on aircraft infringing the noise limits. This study establishes noise abatement procedures and suggests a plan to complement and improve upon NMS in Gimpo International Airport by reviewing the NMS structure. In addition, this study establishes a noise limit at each noise monitoring system and a verification system to discriminate infringing aircraft. Finally, this study suggests a control plan for aircraft Infringing the noise limit.

• 한국음향학회지
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• 제6권2호
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• pp.5-14
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• 1987

소음과 음악이 정신작업에 어떠한 영향을 미치는가를 검토하기 위해, 국민학생을 대상으로 소음그룹과 음악그룹으로 나누어 좌반구작업으로서 수의 가산데스트를, 우반구작업으로서 그림의 패턴찾기 테스트를 실시하였다. 그 결과소음과 음악의 작업에 미치는 영향은 매우 달랐다. 음악그룹의 피험자가 가산작업을 한 경우의 작업량은 평균 작업량보다 다 적은 주기를 나타내는 경향이 있다. 이것은 좌반구에서 가제작업과 음악처리간의 간섭때문이다. 한편, 소음하에서의 의 가산작업은 소음과 가산작업이 좌우 다른 반구에서 처리되므로 소음의 영향은 나타나지 않았다. 소음하의 패턴 찾기 테스트에서는 피험자가 작업중에 동요를 나타내는 경향을 보였다. 의미없는 소음은 우반구에서 처리되기 때문에 이것은 우반구에서의 간섭효과로 실명할 수 있다.

• 한국소음진동공학회논문집
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• 제12권10호
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• pp.758-765
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• 2002

KITECH and ODS performed a study of internal and external noise prediction of the Korean high speed prototype test train(HSR 350X). The object of this study was 3 kinds of cars, trailer car(TT2), motorized car(TMI ) and power car(TPI) and the predicted noise was for the two different driving speeds in free field and tunnel conditions. Data of carbody design and noise sources were delivered from manufactures. Some of noise sources which were not available in the project team, were chosen by experiences of ODS. Internal noise level of each car was predicted for two cases i.e, at 300 km/h and 350 km/h. In addition sound transmission path and dominant noise sources were also investigated for each section of the car, which is circular shell typed part of whole carbody. In case of TT2, the dominating sound transmission path is the (floor in terms of structure-borne noise and air-borne noise. The main noise sources are structure-borne noise from the yaw-damper and air-borne noise from the wheel/rail contact, whereas the dominating sound transmission path of TMI are floor and sidewall below the window in terms of structure-borne noise. The main noise sources of TMI are structure-borne noise from motor/gear unit and the yaw-damper in the free field, and air-borne noise from the wheel/rail contact and structure-borne noise from motor/gear unit in the tunnel. Through the external noise prediction for the KHST test train formation, the noise form the wheel/rail contact is estimated as one of the major sources. In addition, the noise specification of sub-component was proposed for managing each sub-surpplier to reach the KHST noise requirement. The specification provide the sound power of machinery part and transmission loss of component of carbody structure. The predicted noise level in each case exceeded the required limit. Through this study, the noise characteristics of the test train were investigated by simulation, and then the actual test will be performed in near future. Both measured and calculated data will be compared and further work for noise reduction will be continued.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.917-923
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• 2002

KITECH and ODS performed a study of internal and external noise prediction of the KHST test train. The object of this study was 3 kind of cars; trailer car(TT2), motorized car(TM1) and power car(TP1) and the predicted noise was calculated for the two different driving speeds in free field and tunnel conditions. Data of carbody design and noise sources were delivered from each manufactures. Some of noise sources which were not available in project team, were chosen by experiences of ODS. Internal noise level of each car were predicted for two cases i.e, at 300 km/h and 350 km/h. In addition sound transmission path and dominant noise sources were also investigated of each section of car, which is circular shell typed part of whole carbody. In case of TT2, the dominating sound transmission path is floor in terms or structure-borne noise and air-borne noise. The main noise sources are structure-borne noise from the yaw-damper and air-borne noise from the wheel/rail contact, whereas the dominating sound transmission path of TM1 are floor and sidewall below the window in terms of structure-borne noise. The main noise sources of TM1 are structure-borne noise from motor/gear unit and the yaw-damper in the free field, and air-borne noise from the wheel/rail contact and structure-borne noise from motor/gear unit in the tunnel. Through the external noise prediction for the KHST test train formation, the noise form the wheel/rail contact is estimated as one of the major sources. In addition, the noise specification of sub-component was proposed for managing each sub-surpplier to reach the KHST noise requirement. The specification provide the sound power of machinery part and transmission loss of component of carbody structure. The predicted noise level in each case exceeded the required limit. Through this study, the noise characteristics of the test train were investigated by simulation, and then the actual test will be performed in near future. Both measured and calculated data will be compared and further work for noise reduction will be continued.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.254-257
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• 2005

Locations and emission characteristics of noise source of rapier loom are important factors greatly. So, noise characteristics of rapier loom were investigated by the noise source identification as a part of experimental methods in this study. To identify the noise sources of the rapier loom sound intensity was measured under machine operation. In addition, frequency spectra of the sound at operator position was measured along with sound intensity to help identify the noise characteristics of the rapier loom. The results indicate that the sound power level occurs along the rapier loom.

• 한국소음진동공학회논문집
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• 제25권1호
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• pp.58-64
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• 2015

There are a lot of different types of noise from construction site and it depends on construction stage, equipment type and number of operating equipments. The problem is that the almost noise from construction site is high level and some kinds of noise levels are over 100 dB. In addition, if construction site is located in downtown, there are a few options to reduce noise level. Therefore several site mitigation plans were developed to reduce different types of construction noises such as breaker work, gang form and asphalt saw. They were applied in site and evaluated noise reduction performance. The test result of site insertion loss was between 4~8 dB depends on the equipment and type of work.