• Journal of Korean Society of Environmental Engineers
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• v.39 no.12
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• pp.679-684
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• 2017

Recently, the speed of high-speed railway has been rapidly increase with the development of high-speed train design and operating technology. This causes a lot of complaints related the environmental noise in residential areas near the high-speed railway. In order to operate the high-speed railway in accordance with the design speed, noise reduction technology should be developed to meet the noise characteristics of high-speed railway. And it is important to develop the prediction technology by grasping the noise radiation characteristics. In order to meet these requirements, in recent years, infra-research for 400 km/h high speed railway has been conducted. Reliable noise prediction and noise reduction techniques have been developed through this study. This paper is concerned with wind pressure safety and noise performance evaluation of the newly developed 400 km/h noise reduction device. The wind pressure safety and The noise performance of the developed device was confirmed by this paper.

• Proceedings of the KSR Conference
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• 2009.05b
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• pp.409-417
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• 2009

This paper is focused on a relationship between the noise and vibration of a wheelset and the railway irregularity of a high speed railway using a time-varying frequency transform for a preliminary research of the railway condition monitoring by an in-service high-speed railway vehicle. Generally, the monitoring has been performed by a special railway inspection vehicle or industrial engineers for railway maintenance. However, they have been limited at night due to the in-service high-speed railway vehicles, and too slow to monitor all of the section. To solve this problem, the monitoring should be performed by an in-service high-speed railway vehicle. For the research, the noise and vibration of a wheelset are utilized, because they are closely related to the railway condition. They are measured by using some microphones and accelerometers, and stored in an on-board data acquisition system. The signals are post-processed by a time-varying frequency analysis and compared with the result of a railway geometry and profile measurement system. From the comparison, it is able to observe the relationship between the noise and vibration of a wheelset and the irregularity of a high-speed railway. Also, some distinct frequency components are observed, which are not observed in the railway geometry and profile.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.759-763
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• 2006

The World Health Organization(WHO) has recommended population of sleep disturbance as one of the environmental health indicators. But the percentage of respondents who felt highly sleep disturbed, that is, %HSD can???thave application to sleep disturbance from instantaneous noise. Therefore, this study has been carried out to present the technique for assessing sleep disturbance on instantaneous noise quantitatively. The study of sleep disturbance on night time instantaneous railway noise has been undertaken. Noise monitor has been in operation from 22 hours to 7 hours during 6 nights at 12 locations. To assess instantaneous noise induced sleep disturbance, it was decided to measure body movement by actiwatch. %motility was used as indicators of sleep disturbance. %motility is the expected value of probability of motility value during 7 epochs (105s) of any noise event. The measures of instantaneous motility have been related to measures of instantaneous railway noise events. The relationship shows that %motility is a good predictor for assessing sleep disturbance and Korean is more sensitive to noise than European although the railway noise have been considered in this study. This study can be extended to assessing long-term sleep disturbance and give a guideline far policy decision.

• The Journal of the Acoustical Society of Korea
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• v.21 no.2
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• pp.142-149
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• 2002

With rapid industrial development, a railway has become a main traffic means. But, the railway noise has caused much annoyance for the residents living nearby railway tracks. Therefore, execute regulation standard of railway noise has established for quite dwelling environment from January 2000. However efficient soundproofing measures are very difficult because of the lack of basic data and insufficiency of the existing research. In this point, this study attempts to survey the characteristics of attenuation and propagation of railway noise. And this study intends to get the basic data for establishment of a standard for domestic railway noise.

• Journal of KSNVE
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• v.8 no.2
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• pp.289-296
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• 1998

To predict the noise propagation from an elevated railway, sound radiation characteristics of elevated structure are measured by using the sound intensity method. In the base of the results, we propose the source model of elevated structure noise and the calculation model for elevated railway noise. Acoustic model of the former is modeled a row of single sources with directivity cos .theta. positioned in the center of a bogie and arranged in the lower side of slabs. Also prediction model is presented with rolling noise and elevated structure noise calculated by considering the power level of a source for one-third octave band, ground absorption and barrier deflection. Noise level unit patterns of a passing train is calculated based on this model and the results are compared with available field data.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.882-886
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• 2007

People living in the large cities are exposed to high level noise due to road-traffic, railway-traffic and aircraft. Nowadays, some researches are ongoing to reduce the noise by using noise map. However it has to be decided which prediction model is the most suitable in Korea. In this study, it has been focused on railway noise prediction models which are employed in a commercial software(Sound Plan) and developed by Korea Railroad Research Institute, and comparative study of the prediction models has been made.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.500-504
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• 2008

Residents in an area where both trains and cars pass through are exposed to not only road traffic noise but also railway noise. Nevertheless, the degree of annoyance the caused to the residents is being under evaluated as the noises have been evaluated separately. Therefore, this study aimed at evaluating the integrated noise of road traffic and railway, and proving the accuracy of the evaluation result.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.366-371
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• 2004

For the reduction and efficient management of railway noise, first of all prediction of railway noise is necessarily requisted. At home and abroad many studies for prediction of raiiway nearby noise have been accomplished. But it is impossible to predict easily and exactly for the Korean Railway, because the acoustic powers for each rolling stock operated in Korea have not been built yet. So in this study, prediction model equation for environmental noise for Korean rolling stock Mugungwha was suggested using SEL of engine and rolling noise component separately. In this prediction model, the number of car, distance from the rail can be considered. Finally for the validation of prediction nlodel equation, the predicted Leq was compared to the measured Leq.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.7
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• pp.741-745
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• 2008

Residents in an area where both trains and cars pass through are exposed to not only road traffic noise but also railway noise. Nevertheless, the degree of annoyance the caused to the residents is being under evaluated as the noises have been evaluated separately. Therefore, this study aimed at evaluating the integrated noise of road traffic and railway, and proving the accuracy of the evaluation result.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.11
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• pp.1020-1026
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• 2013

An accurate railway environmental noise prediction model is required to make the proper solution of the railway noise problems. In this paper, an engineering model for predicting the noise of conventional passenger cars is presented considering the acoustic source strength in octave-band frequencies and the propagation over grounds with varying surface properties. Since the formation of a train can be variable, the source strength of each locomotive and passenger car was estimated by measuring the pass-by noise and analysing the wheel-rail rolling noise. Some validation cases show on the average small differences between the predictions of the present model and the measurement results.