• International Journal of Railway
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• v.5 no.2
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• pp.84-88
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• 2012

Derailment due to wheel failure would cause a tremendous social and economical cost in service operation. It is necessary to evaluate quantitatively the safety with respect to high-speed train. Although the safety of railway wheel has been ensured by an regular inspection, all critical defects cannot be detected in inspection cycles and the wheel has been replaced because a defect quickly become critical for safety. Therefore, it is important to calculate quantitatively the fracture limit and remnant life of damaged railway wheel in wheel-rail system. In present paper, the critical crack size of wheel for high-speed train is simulated based on fracture scenario and the safety of wheel is evaluated.

• Journal of Auto-vehicle Safety Association
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• v.10 no.4
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• pp.50-53
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• 2018

Some local government, community rehabilitation center, special school operate buses which can be used by wheel chair user in order to commute. However, there are no regulations or laws for safety management of buses and its wheel chair lifts. To prevent discrimination among the physically challenged people, government of Korea plan to supply buses which wheel chair users are able to on board. Safety management system should be prepared to ensure safe and convenient use of express and intercity buses for wheel chair users. In this study, domestic and international standards and regulations of wheel chair lift are thoroughly reviewed and based on this research, national safety standards for wheelchair lift are suggested for the future.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.664-669
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• 2004

In rolling stock, wheels are one of the most important components to run on the track in safety. Especially, it is important that wheel profile cause the variation of dynamic characteristics and running safety. The purpose of this paper is to propose the wheel profile and to know the effectiveness of improved wheel profile by using microphones. We also performed analysis of running safety to know application of improved wheel profile before the test. In result, the improved wheel profile was stable in running safety and noise level was reduced.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.4
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• pp.642-652
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• 2010

This study examines the inconveniences and problems of established safety-equipment by investigating the actual conditions for elderly people who use welfare services such as wheel chairs provided by care institutions. Suggestions will be made on how to improve the function and convenience of use to suit the needs of the elderly and how to create beautiful wheel chair safety-wear. Medical treatment helpers for the elderly were surveyed about the wearing conditions of wheel chair safety equipment. The present wheel chair safety equipment was shown to be aesthetically unpleasant; in addition, feelings of restriction and unpleasantness were noted (concerning the wearing of the equipment). In addition, there was no feeling of fixed stability. The wheel chair safety-wear that has been designed reflects the inconveniences and problems of current wheel chair safety equipment in material, design, and patterns along with the results of those surveys. Both objective and subjective tests compared the manufactured safety-wear with current equipment. According to the results, the new safety-wear is superior than existing ones.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.7
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• pp.591-595
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• 2015

The roller rig tester for safety performance evaluation of wheel derailment is a test facility which can give the test load condition to the test wheel, similar to the actual dynamic condition in actual running condition. This study describes the evaluation result on the durability of the resilient wheel equipped with the ring damper and the damping material, and installed in the half part of a full scaled bogie in combination with the primary spring when it rotates under the dynamic condition. The evaluation result on durability of resilient wheel after load test of 2 million cycles shows that the safety of wheel is not affected by the applied load in visual inspection and nondestructive test, however, in the bolt used for fastening the ring damper to the wheel the loosening was found. Accordingly the use of self-locking nut and washer is recommended.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.262-267
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• 2006

The maximum speed of the conventional railway rolling-stock which is restrained to 150km/h will be increased to 200km/h with the development of korean tilting train. The improvement of quality for railway wheel which is closely connected with the safety of train is needed. On the one hand, the speed limit of the wheel standard for the conventional rolling-stock is 150km/h. Thus, a study on the safety of wheel structure, test items and criteria is needed to apply this standard to tilting train wheel. This study is started to present the improvement scheme and to extend the speed limit for conventional wheel standard. For this, we studied the safety of wheel structure, wheel material tests and the criteria for wheel standard and show the results

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.606-610
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• 2004

In this paper, we would like to explain about the structure analysis of wheel set as variation of contact position between wheel and rail. Measurement of interacted force between wheel and rail is necessary for running safety evaluation as important factor of derailment mechanism. It's necessary to running safety evaluation of rolling stock. Wheel unload and lateral force change as variation of contact position between wheel and rail. Interacted force between wheel and rail got as each contact position through computer simulation. This is necessary process as first research for evaluation of derailment phenomenon and running safety.

• Journal of the Korean Society of Safety
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• v.32 no.5
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• pp.41-46
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• 2017

The coefficient of derailment and the rate of wheel load reduction were used as the index of train running safety that was directly affected the train derailment safety. In aspects of track, the train running safety depends on the complex interaction between wheel and rail, and the track-vehicle conditions (i.e., the curvature, cant, track system, vehicle speed and the operation conditions, etc). In this study, the relationship between the train running safety and the track curvature and vehicle speed for direct fixation concrete tracks currently employed in Korean light rapid transit was assessed by performing field tests using actual vehicles running along the service lines. The measured dynamic wheel load, lateral wheel load and lateral displacement of rail head were measured for same train running on four tested tracks under real conditions, which included curved and tangent tracks placed on the tunnel and bridge, thus increasing the train speed by approximately maximum design speed of each test site. Therefore, the measured dynamic track response was applied to the running safety analysis in order to evaluate the coefficient of derailment, the rate of wheel load reduction and the track gauge widening at each test site, and compare with the corresponding Korean train running safety standard. As the results, the lateral track response of direct fixation concrete track appeared to increase with the decreased track curvature; therefore, it was inferred that the track curvature directly affected the train running safety.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1703-1712
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• 2010

The safety of tilting train running on curved track is, in general, evaluated with a derailment coefficient calculated by the ratio of wheel load and lateral force, Particularly on curve, the wheel load and lateral force on rail may cause trackbed to be deformed, depending on their intensity, and moreover, often result in critical accident such as derailment. This study hence was intended to identify the cause of wheel load and lateral force so as to suggest the allowable wheel load reduction rate, lateral force limit and derailment coefficient, thereby quantitatively evaluating the operational safety of tilting train. This study therefore was aimed to analyze the wheel load and lateral force occurred during tilting train's operation on circular curve in such a way of comparing with traditional trains, by axle and speed, in a bid to eventually evaluate the operational safety of tilting train.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.5
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• pp.895-901
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• 2016

Nowadays, the axle counter has been developed to the wide range of the track circuit blocks as well as the wheel detection device. The axle counter, as becoming an important device for the high speed railway, must be guaranteed in accordance with the safety. With considering the safety and the high speed, performance evaluation a wheel detection sensor is described in this paper. To increase the safety, digital proximity sensor instead of analog is employed in the wheel detection sensor. Therefor the wheel detection sensor can minimize noisy signals caused by the harsh railway environments. And, to meet the high speed railway requirements, the performance of the wheel detection sensor is also successfully verified using the speed simulator at the velocity 500Km/h.