• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1890-1901
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• 2007

This paper explored train frequency of intercity rail station. Main factors to decide train frequency are location of station, social-economic index and land use of station area and travel demand. In this paper, we focused on travel demand which is critical factor to decide train frequency. Tests on a KTX case show that train frequency can be efficiently decreased in weekday to transport same demand. The work has shown many subjects that need further research. It is important to include various factors influencing on train frequency decision.

• International Journal of Railway
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• v.9 no.2
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• pp.41-45
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• 2016

In this paper, a study on the efficiency improvement of the magnetic levitation train using the LIM (Linear Induction Motor) was presented. The maglev train has the advantage of being environmentally friendly since much less noise and dust is produced. However, due to structural limitation, compared to a rotating induction motor, linear induction motor, the main propulsion engine of the maglev train has a relatively greater air gap and hence has the lower operation efficiency. In this paper, the relationship between the operating condition of the train and the slip frequency has been investigated to find out the optimum slip frequency that might improve the efficiency of the magnetic levitation train with linear induction motor. The slip frequency is variable during the operation by this relationship only within a range that does not affect the levitation system of the train. After that, the comparison of the efficiency between the conventional control method with the slip frequency fixed at 13.5[Hz] and the proposed method with the slip frequency variable from 9.5[Hz] to 6.5[Hz] has been conducted by simulation using Simplorer. Experiments of 19.5[ton] magnetic levitation trains owned by Korea Institute of Machinery and Materials were carried out to verify the simulation results.

• Journal of the Korean Society for Railway
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• v.9 no.1 s.32
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• pp.18-22
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• 2006

The dynamic characteristics of the current collection system are investigated by conducting a test run in which signals from accelerometers and load cells attached to the various parts of the pantograph are analyzed in both the time and frequency domains. The dynamic characteristics of the current collection system are found to be strongly influenced by the train speed; the fluctuation in the pantograph motion increases in direct proportion to the train speed. There exist two major fequency components in the pantograph motion related to the current collection, a speed-dependent component arising from the train traversing a span of the catenary, and a speed-independent component related to the pantograph resonant frequency. The train acceleration is also found to exert strong influence on the current collection system characteristics. The effect of the train motion is found to be stronger on the speed-dependent frequency component than on the speed-independent one.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1134-1139
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• 2007

In recent years, public complaints about railroad noise by KTX and Ordinary train are increasing. Restriction of railways uses same standard without distinguishing the type of railways. According to the type of railways, the frequency characteristics of emitting noise is different. Therefore it is requested to know how vary the public response to each types of railway. The noise annoyance to three types of trains (KTX, Electric train, Diesel train) was analyzed by Jury Evaluation Test for assessing the effect of frequency characteristics. The numerical results by a Semantic Differential Method showed that annoyance response to three type of trains depended on the frequency characteristics. As a result, this study proposed that the KTX could have a bonus level of maximum 2.9dB(A) to ordinary train.

• International Journal of Safety
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• v.5 no.1
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• pp.1-4
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• 2006

The safety performance of the current collection system is evaluated by conducting a test run in which accelerometer and load cell signals are analyzed. It has been found that the current collection performance is strongly influenced by the train speed, with the major frequency components arising from the train traversing the span spacing and the 8.5 Hz component originating from the panhead resonance. The train acceleration is found to have significant influence on the span passing frequency but negligible effect on the resonant response.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.1
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• pp.237-242
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• 2017

This paper presents development of the transponder system which provides an accurate train position, especially for supporting 400km/h high speed train. Here, we analyzed an operating frequency band of the transponder system which can be interoperable with the Eurobalise system already installed in Korea railroad as to be used for the automatic train protection (ATP). By investigating the power frequency band and its data frequency band of the transponder system, we presents the adoptable frequency band for the developed transponder system. Additionally, through the real testbed using HEMU-430X, we evaluate its performance requirement and shows interoperable operation with the Eurobalise system.

• Proceedings of the KSR Conference
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• 2002.10b
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• pp.1035-1040
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• 2002

Railway plate girder bridges have characteristics that are not show dominant frequency in dynamic response frequencies like obtained vertical acceleration on the bridge during the train passing because the train loading relatively bigger than the bridge self-weight. This paper experimentally confirmed in FFT result has various frequencies due to inherent characteristic of railway train loading. To establish classification of dynamic frequency range in railway bridge acceleration during the train passing, vibration frequencies result from experimental test are analyzed concerning actuation vibration factors. Factors are train velocity, train type, mass ratio of vehicle/bridge, stiffness of bridge, bridge/track and vehicle/track. From the result, it is proposed that the frequencty classfication table with corresponding factors. Using the proposed table to develop rehabilitation technique of the plate girder bridge, to expect vibration reduction and comfort enhancement of the railway plate girder bridge.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.4 s.247
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• pp.473-480
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• 2006

This paper explains analytical and experimental studies to evaluate the natural frequency of a composite carbody of Korean tilting train. The composite carbody with length of 23m was manufactured as a sandwich structure composed of 40mm-thick aluminium honeycomb core and 5mm-thick woven fabric carbon/epoxy face. From the finite element analysis, the 1st bending and 1st twisting natural frequency of the composite carbody were 11.67Hz and 14.4Hz, respectively. In order to verify the analytical results, the natural frequency measuring tests were performed. The measured 1st bending and twisting natural frequencies of the composite carbody were 10.25Hz and 11.0Hz, respectively. Both of these results satisfied the design requirement.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.3
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• pp.335-344
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• 2008

In recent years, public complaints against railroad noise by KTX and Ordinary train have been rising. Regulation of railways noise uses same standard without distinguishing the type of railroad cars. According to the type of railroad cars, the frequency characteristics of emitting noise is different. Therefore it is requested to know how the public response vary to each types of railroad cars. The noise annoyance from three types of trains(KTX, electric train, diesel train) was analyzed by jury evaluation test for assessing the effect of frequency characteristics. The numerical results by a semantic differential method showed that annoyance response to three type of trains depended on the frequency characteristics. As a result, this study proposed that the KTX could have a bonus level of maximum 2.9 dB(A) compared to ordinary train.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.163-170
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• 2001

Axle Gearbox of the High Speed Train has rotational degree of freedom centered on the Axle Shaft Center Line, and constrained by the Reaction Arm connected to the Bogie Frame via Resilient Ring made of Rubber. This System is laid on the Power Train and can influence on the Power transmitted from Motor to Axle. The stiffeness of the Resilient Ring have to be selected for the Natural Frequency of this System do not overlap with the Teeth-mating Frequency. To confirm the Design Parameters, Calculation and Experiment were executed and compared.