• International Journal of Railway
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• v.4 no.3
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• pp.70-73
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• 2011

Controlling the exterior and interior noise emission has become an important issue in the research and development of high speed trains. As the operating speed of the train increases, the noise emission characteristics are expected to deviate from that of the existing trains due to several changes in the basic train layout. For train speed in excess of 350 km/h in particular, the aerodynamic noise component starts to exceed the structure-borne noise component, and even an incremental speed increase is accompanied by a rapid elevation in the noise level. The present study presents an engineering approach for predicting the aerodynamic noise level at the design stage for high speed trains. The experimental noise measurements from test run of Korean high speed train under development are presented as a partial validation of the proposed approach. While the overall aerodynamic noise can be cast in a single power law relationship against the train speed, different parts of the train show power law relationships unique to each component.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1325-1326
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• 2011

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.97-100
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• 2007

This study deals with the sound insulation performance of the damping sheet, which is widely used in a train. The wall of train is assumed to be a plate made of steel and two damping sheets. In case of damping sheet only, the sound transmission loss follows the mass law. If a steel plate is attached to damping sheet, the transmission loss is found to be higher than single of only steel plate, as we can anticipated, about $3{\sim}5$ dB. This is very well known consequence that is because the density of area increases. However, the increase of the transmission loss is not higher than what we can expect by the mass law. That's because the steel is perfectly blocked from the transmission of the air ; There is no defect in that material.

• Proceedings of the Safety Management and Science Conference
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• 2012.04a
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• pp.233-243
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• 2012

HBD(Hot Box Detector) is a device to monitor temperature rises to inappropriate lubricant use or mechanical defects. If a train operates without recognizing such an effect, it might result in bearing overheating due to defects and cause a dangerous situation that it could derail a train owing to the damage of axles. Now for the Gyeongbu HSL at 300km/h, the laws related to monitoring overheated axle bearings are notified in the Railway Safety Law and the Railway Construction Law. But in case of the conventional speed-up lines that a train operates at 180 to 230 km/h, the revised bill of relevant standards is ongoing. Therefore in this paper we present references and reviews investigated in order to use the optimal HBD in the conventional speed-up lines.

• Journal of Industrial Technology
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• v.31 no.A
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• pp.33-38
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• 2011

In an express tilting train, side wall insulating the noise from the exterior sound source consists of two parts. One is the layered composite panel including aluminum honeycomb, glass wool and nomex honeycomb. The other is the double glazed window. In this study, sound insulation performance of the two parts is investigated by mass law and experiment. Based on ASTM E2249-02, the intensity sound transmission loss (TL) is measured on the specimens of the two parts. Mass law deviation (MLD) is considered in order to compare the sound insulation performance in respect of weight. Contribution of each part to the sound insulation is analyzed and the sound insulation strategy for the interior noise reduction is investigated.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.172-178
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• 2007

The purpose of Railroad Vehicles License Management in accordance with the Railroad Safety Law is to improve the quality of railroad safety. And the train simulators come into use for training of train operation and testing to issue Railroad Vehicles License. So, It is very important that the simulators for the Railroad Vehicles License Test require to work correctly, to measure driver's operation quality in numerical system and to ensure the justice of license test. In fact, nobody can guarantee that the simulators are feasible performance to use in license test. The simulator for train driver license test can be used effectively for studying of needed performance and quality to test new driver's skill. This study hopefully provides the base for improving the quality of the simulator for train driver's license test and contributes furthermore to improve the simulator development technology and railroad safety.

• Composites Research
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• v.24 no.5
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• pp.9-16
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• 2011

This paper describes the crashworthiness evaluation and performance improvement of tilting train made of sandwich composites. The applied sandwich composite of carbody structure was composed of aluminum honeycomb core and glass/epoxy & carbon/epoxy laminate composite facesheet. Crashworthiness analysis of tilting train was carried out using explicit finite element analysis code LS-DYNA 3D. The 3D finite element model and 1D equivalent model were applied to save the finite element modeling and calculation time for crash analysis. The crash conditions of tilting train were conducted according to four crash scenarios of the Korean railway safety law. It found that the crashworthiness analysis results were satisfied with the performance requirements except the crash scenario-2. In order to meet the crashworthiness requirements for crash scenario-2, the stiffness reinforcement for the laminate composite cover and metal frames of cabmask structure was proposed. Consequentially, it has satisfied the requirement for crash scenario-2.

• Journal of the Korean Society for Railway
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• v.10 no.4
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• pp.398-404
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• 2007

The objective of this study is to verify the hypothesis that cognitive process of railway drivers would be influenced by train speed. The hypothesis is tested by investigating railway drivers' cognitive processes at different speeds of a locomotion. The experiment shows that human performance of railway drivers decreases as the train speed becomes faster. In addition, simple signals outperformed complex signals at every train speed. Therefore, it is suggested to redesign complex signals simpler for improving drivers' human performance. It is also recommended that the Korean railway safety law should be revised to mention requirement of the signal design, especially for the fastest train including KTX. The implications of the experiments are discussed in detail.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1210-1213
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• 2006

Indoor air quality is an important determinant of human health and comfort. However, the complexity of pollution sources and the multitude of parties responsible for creating indoor exposures makes the improvement of air quality difficult. The KTX HVAC(Heating, Ventilating and Air-Conditioning) system is important facility to provide comfortable environment passenger service. The Ministry of Environment is planning to enforce$\square\square$Indoor Air Quality Management law in Public Facilities$\square\square$in year 2008. Hereupon, the train and the subway are included. In this research air quality in the KTX Train compartment has measured. As a result, The average amounts of PM10(particulate matters), $CO_2$(carbon dioxide)measured $20{\mu}g/m^3$, 1,097ppm in KTX respectively. There are compare to regulation the value is 10% for PM10 and 43% for $CO_2$. Thus, the indoor air quality of KTX train have been proved satisfy the recommendation the Ministry of Environment guidelines.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2256-2262
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• 2011

In this study, sound transmission loss (STL) is investigated on the multi-layered windows used in the KTX-sancheon and next generation HEMU-400x high speed train. Using TLOSS, which is developed as a special purpose STL analysis program, STLs of the multi-layered glass windows are analytically investigated and compared with the mass law result. Window specimens for the two train models are manufactured and intensity transmission losses are measured based on ASTM E2249-02. The problems in aspect of sound insulation are diagnosed on the two window models. The aim of this study is to provide useful data for the improvement of the interior noise in the high speed train.