• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.83-86
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• 2005

The aim of this study is to establish the indoor noise limits of apartment houses for mad traffic noise. To achieve this goal, psycho-acoustic experiments were carried out with the mad traffic sound sources modulated by the transmission loss characteristics of the external windows. As a result of this study, followings are suggested. 1) On correlation between dose level and psycho-acoustical response, the initial level of negative feeling is located on $40.1{\sim}40.6$ Leq dB(A). 2) On the degree of satisfaction to road traffic noise, near 35% Point being same dissatisfaction degree is to be assumed $40{\sim}41$ dB(A) of indoor noise level presented into three vocabulary. It is suggested to be reasonable level of 40 dB(A) on the indoor noise limits for intruding road traffic noise, and it is appropriate to be the 5dB level difference between grades.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.277-282
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• 2006

Road traffic noise is not produced by any one factor rather occurs as a composition of various factors. Its occurrence is made by running engine noise, tire frictional, and exhaust noise etc. The quality of the noise depends on the size of the vehicles, rotation and engine speed, vehicle load, package state of the road and incline etc. The occurrence of noise level of heavy trucks appears louder than smaller vehicles and the noise levels produced differs according to speed and load etc between similar size vehicles. Other factors such as traffic density, average speed, mixing rate of heavy vehicles, and the distance between vehicles also generate road traffic noise. In this paper we examine 2, 4, and 6-lane roads in Jeonju. Consequently, this study examined the means used to measure road traffic noise. It was found that when there is a large traffic density and the average velocity is below 70 km/hr, the noise level could receive a relative proper value by the current measuring means. But in the case of night-time, it was found that the current measuring method is inapposite.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1276-1279
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• 2006

This article on environmental noise qualify is concerned with the relationships between the annoyance and perception and sound quality metrics according to exposition time for traffic noise. For invested the characteristics of noise quality, we conducted to the subjective experiments of the annoyance response using the absolute 100 scaling method for the traffic noise sources. The traffic noise sources are composed to varieties exposition time from 15sec to 1200sec. As the results, the first there are decreased the perception loud level for the increase of exposition time with logarithm scale, but increased the annoyance. Second, evaluation index of annoyance is correlated to the loudness(sones), tonality and logarithm scale time with R2=0.83. Also, the composition ratio of traffic noise according to exposition time has the change of range as the logarithm scale ($30{\sim}50%$), tonality($27{\sim}37%$) and loudness($34{\sim}20%$).

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.2
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• pp.1-8
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• 1987

Recently, as subway traffic have been increased, vibration of each parts of subway influence on structures above subway tunnel. This paper presents a new method to reduce which was generated by subway traffic. By comparing directional coherence relationship of X, Y, Z-axis and vibrational coherence relationship of spherical signal which was unified by three directional signals, effective vibration diminishing method was proposed. It can be found that locomotive vibration(specially 1-2Hz) have the worst effect on the vibration of structures and the vibration of subway box ranked 2nd, the vibration of earth ranked 3rd.

• Geomechanics and Engineering
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• v.24 no.2
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• pp.143-156
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• 2021

Rail transit lines usually pass through many complicated topographies in mountain areas. The influence of inclined bedrock on the train-induced soil vibration response was investigated. Model tests were conducted to comparatively analyze the vibration attenuation under inclined bedrock and horizontal bedrock conditions. A three-dimension numerical model was built to make parameter analysis. The results show that under the horizontal bedrock condition, the peak velocity in different directions was almost the same, while it obviously changed under the inclined bedrock condition. Further, the peak velocity under inclined bedrock condition had a larger value. The peak velocity first increased and then decreased with depth, and the trend of the curve of vibration attenuation with depth presented as a quadratic parabola. The terrain conditions had a significant influence on the vibration responses, and the inclined soil surface mainly affected the shallow soil. The influence of the dip angle of bedrock on the peak velocity and vibration attenuation was related to the directions of the ground surface. As the soil thickness increased, the peak velocity decreased, and as it reached 173% of the embedded pile length, the influence of the inclined bedrock could be neglected.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.613-617
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• 2007

Noise maps of a city in Korea have been made using commercial noise map softwares by measuring the basic data in the city. The result in this study will be used to evaluate the environmental impact of noise from various noise sources and to implement the Korean noise map standard.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1996.10a
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• pp.131-137
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• 1996

To perform condition monitoring of P.C. Box girder bridge under ambient traffic, dynamic characteristics were identified using the results of load test an analysis. It was found that natural frequencies obtained from the measured acceleration data for the forced vibration part and free vibration part were nearly identical. Thus it can be concluded that dynamic parameters are properly determined under ambient traffic condition. Finite element model for analysis was calibrated using measured frequencies. Change of dynamic characteristics were predicted through analysis of the established finite element model with anticipated change.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.616-622
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• 2001

The road traffic noise becomes aggravated due to the rapid increase of motor vehicles. It has a great effect on the dwelling environment. Therefore we investigate the characteristics and sources of the motor vehicle noise through grasping the status of the motor vehicle noise. Traffic noise results from the collective contribution of the noise produced by individual motor vehicles. The motor vehicle noise varies enormously depending upon its type and mode of operation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.1040-1044
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• 2001

This study is to propose an analyzing method of road traffic noise in apartment sites using computer simulation program. The evaluation method used in this study is to calculate "Site Equivalent Noise Level". It will be possible to set up effective sound proof system with calculation of "The Number of Houses Exceeding Standard Noise Level".

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.357.1-357
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• 2002

The purpose of this study is to propose indoor noise level in residential buildings affected by transportation noise (road traffic, railway and air-craft noise) based on subjective evaluations. 30 subjects participated in the experiment to evaluate the noise. Experimental environment reproduced real living and office environment, and in asking subjects' annoyance to the noise. (omitted)