• Proceedings of the KSR Conference
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• 2011.10a
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• pp.329-336
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• 2011

Urban transit is promoting improvement of the concrete track to solve many problems maintenance in ballasted track. But concrete track has a lot of noise compared to ballated track by multiple reflections. The concrete track is to install sound absorption blocks to reduce noise. And it has a lot of research and effort. This is study analyzed the effect of sound absorption blocks though field measurements, in the range of installed sound absorption blocks. And this was an analysis of the surface shape and sound absorption effects of sound absorption blocks.

• Journal of KSNVE
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• v.6 no.3
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• pp.349-355
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• 1996

For a rail traffic noise, a typical source has a length of 200m - 400m so that the noise pollution areas have been located in the transition regions where the sound level drops between 3dB/dd and 6dB/dd. Therefore, in this region, parameters such as a horizontal distance from the track, the geometry of the ground surface, the environmental effect, and the boundary impedance condition play import roles, especially in our nation's situation. In this study, modelling techniques for the finite length of noise source have been investigated in order to evaluate the rail traffic noise level. Then. noise correction value .${\Delta}$SPL for various location in the track region is represented by the non-dimensionalized horizontal and parallel distance from the track. As an application, a high speed train is examined. Beas on the noise data measured for a Eurostar in France, the sound power value per unit length $H_1$is calcuated. It turns out that$H_1$is 109 dB. Overall sound power from the highspeed train to be serviced in our country is expected to 135 dBA.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.1
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• pp.1-9
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• 2017

In this study, a test-bed system simulated a tunnel and concrete track is tested on cite and invested an allowed limit of multi-layered sound absorbing panel for reducing noise reflected on the concrete track in train tunnel considering the criteria and limitation on the theoretical back ground. The studied results are an effective evaluating system of the sound absorbing coefficient influenced fluid effects depending on the vehicle speed in the urban train tunnel and measuring not only structural behaviors of maximum displacement and acceleration of the panel but also dynamic characteristics of damping ratio and natural frequency.

• Journal of Broadcast Engineering
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• v.13 no.5
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• pp.602-611
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• 2008

The sound design performed in the production of media contents, such as TV, movie, and CF, have been conducted through the experienced feeling of some experts in the aspect of auditory effects that communicates stories. Also, there have been few studies of the quantitative approach and verification to apply visual and auditory effects felt by users. This study is a non-equivalent control group pretest-posttest design and investigates the difference in communication effects in which the difference in a sound design in the production of media contents that affects users. This study analyzed the brain quotient (BQ) obtained by the measurement of brain waves during the watching of an experiment image (track A) designed by using a 60-second TV CF only and an experiment image (track B) designed by sound effects and music and investigated which sound design represents differences in communication effects for users. The results of this investigation can be summarized as follows: First, in the results of the comparison of the attention quotient (ATQ), which is the BQ of recognition effects, between A and B tracks, the track A showed a higher difference in activation than the track B. It can be analyzed that the sound design based on music showed higher levels in attention and concentration than that of the sound effect design. Second, in the results of the comparison of the emotional quotient (EQ), which is emotional effects, between A and B tracks, the track A represented a higher difference than the track B. It means that the sound design based on music showed higher contribution levels in emotional effects than that of the design based on sound effects. Third, in the results of the comparison of the left and right brain equivalent quotient (ACQ), which is memory activation effects, between A and B tracks, there were no significant differences. In the results of the experiments, although there are some constraints in TV CF based on the conventional theories in which sound effects based design affects strong concentration, and music based design affects emotional feeling, the music based design may present more effects in continued concentration. In addition, it was evident that the music based design showed higher effects in emotional aspects. However, it is necessary to continue the study by increasing the number of subjects for improving the little differences in ACQ. This study is useful to investigate the communication effects of the sound based design in media contents as a quantitative manner through measuring brain waves and expect the results of this study as the basic materials in the fields of sound production.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.479-484
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• 2005

Comparison it analyed the tunnel travelling hour interior noise arresting quality of the inside and outside of the country high-speed vehicle from the research which it sees. In the interior sound arresting comparison objective vehicle of the tunnel travelling hour KTX vehicle from the research which it sees and it limited by the TGV vehicle of France and the ICE vehicle og Germany and the Shinkansen vehicle of Japan comparison it analyzed the interior sound arresting from the open field and the tunnel line. The tunnel passage hour interior sound arresting problem of the domestic KTX vehicle follows in the concreate track tunnel the ballast track tunnel and the interior sound arresting quality is appearing different.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.737-747
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• 2011

5678SMRT has installed various sensor for operating conditions(field of electric, facilities, signal, communication equipment and track) and environment of Every Function Room for remotely detecting and monitoring. Installed sound sensor for analyzed after remotely heard the noise of every equipment at Every Function Room and temperature sensor for check the temperature condition of Every Function Room. Additional installed voltage sensor in signal equipment room for monitoring RF track-circuit's voltage condition. Installed displacement sensor at The Chungdam bridge's railway for measuring and monitoring track displacement caused by temperature change and Pan/Tilt camera at sub-station and drainage for remotely field monitoring. Installed sensor for each equipment's operating condition and failure at Every Function Room then periodic check of workforce turned to around-the-clock surveillance by sensor therefore improvement of operating equipment. SMRT is lots of prevent a failure by Immediately detect of precondition of equipment failure by analyzed the sensor data. If the occurrence of an failure, become detected Immediately so possibility correct diagnosis and order by remotely field check by installed camera and sound sensor at field.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.361-368
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• 1998

This paper sums up the study of the soundproof facilities to be placed on the test track section within the Seoul-Pusan H.S.T project. The objective of this study is to determine optimum design of soundproof including height, length, location, sound absorbing materials for test track(chonan-taejon). This paper shows the model to design the shape and materials of noise barrier for high speed trains(TGV, ICE, etc). Noise prediction is to be conducted by MITHRA. Various parameters affecting the noise propagation outdoors are surveyed and discussed in relation to H.S.T. noise.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.2
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• pp.208-213
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• 2007

As recent research on home service robot has been performed actively in these days. It becomes very important for the robot to react upon voice and sound source, and then tracks an object position in dynamic environment like a home. When people choose a path for finding a destination of objects, in case of sound, they track a direction of the sound source. Or in case as a position of the object be girded with a point on map, people track the position according to absolute orientation of the present position and the sound source position. In this paper, In this manner we had views on what people decide own direction when they react one's voice or go some directions. We suggest a algorithm that intelligent mobile robots on which we installed a sound source tracking board and a digital magnetic compass board go some object's positions by the direction of sound source and absolute orientation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.644-647
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• 2013

The important source of noise from railways is rolling noise caused by wheel and rail vibrations induced by acoustic roughness at the wheel-rail contact. The main contributors for rolling noise are the sleepers, rail and wheels. In order to analyze and predict rolling noise, it is necessary to understand the vibrating behaviors of railway tracks, as well as the wheels. In the present paper, theoretical modelings of the railway track are reviewed in terms of the rolling noise, and they are applied for the three representative types of domestic railway tracks operated: the conventional ballasted track, KTX ballasted track and KTX concrete track. The characteristics of waves propagating along rails were investigated and compared between the tracks. The tracks were modeled as discretely supported Timoshenko beams and compared in terms of the averaged squared amplitude of velocity which is directly related to the sound radiation from the rails.

• Journal of KSNVE
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• v.8 no.4
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• pp.603-608
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• 1998

In order to obtain basic data for the prediction of railway noise propagation, the noise radiation characteristics (source position, radiation directivity, etc) of trains were measured by using the sound intensity method. The measurements were performed at a side of railway by setting an intensity-probe array. As the measurement results, it was found that rolling noise due to interaction between wheel and rail and motor noise radiation from the lower part of train are dominant. The location of main sound sources can be described as being at the height of 0.1m in the center line of track, and the radiation directivity in the cross section of actually running trains are presented as a dipole source.