• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.390-392
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• 2001

This paper presents an intersection of technologies of ITS (intelligent transport systems) and CBTC(communication based train control) in urban transit system. ITS is based on Information and communication technologies. And also these techniques are fundamental for railway system. ITS has some technologies useful in railways such as traveler information service, public transportation information service, and advanced vehicle control Systems. Therefore, both systems need to technological cooperation. In this paper, we proposed useful an cooperation method for both systems.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.471-473
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• 1999

Recently, the computer based control systems instead of conventional relays circuitry are widely used to industrial applications, and also those technology is available to railway signaling which are safety-critical systems. However, the safety and reliability of software for those systems are harder to demonstrate than in traditional relays circuitry because the faults or errors can not be analyzed and predicted to those systems. So, the safety problems are crucial more and more in computer based control system. In this paper, the GRAFCET(GRAphe Fonctionnel do Commande Etape/Transition) language is used as a analysis and verification tool for safety-critical interlocking logic. The general description for Grafcet notation are provided and the general modeling for interlocking logic is presented.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.119-125
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• 2016

This study examined the running dynamic characteristics of a hybrid type wheel-rail high speed train, in which the propulsion method of maglev is applied. A wheel-rail high speed train propelled by a superconducting linear synchronous motor (SC-LSM) is expected to be superior to a maglev train regarding economical and interoperable aspects, still having powerful thrust force as maglev. In this paper, regarding the two methods of applying the SC-LSM to an existing wheel-rail train, to investigate the influences of SC-LSM propulsion on the dynamic characteristics of wheel-rail high speed train, the dynamic model of train including interaction between the rotor and stator of SC-LSM is established. Through the simulation using the model, the influence of the interaction between the rotor and stator of SC-LSM on stability, ride comfort and the effect of guideway irregularity are investigated.

• Journal of Digital Convergence
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• v.14 no.5
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• pp.283-291
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• 2016

The railroad is one of the most popular means of transport. However, railroad agencies are managing the railroad information and provide its service respectively. That is, because of managing the different information and its type, the user will not receive the correct and integrated information. Thus, it is needed to employ methods for converting the various types of railroad information into the unified railroad information. In this study, we investigated how to (semi-)automatically convert railroad information in each agencies to standard railroad information. Railroad passengers can use the railroad information service at a time, at a glance and in one place. In addition, we believe that there can be provided the opportunity to create an new service, which will dramatically develop a railroad information service through these systematic and integrated railroad information management.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.600-604
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• 2007

Techniques related to railroad industry have progressed rapidly and the automation of work is prevailing. Since the railroad accidents due to the human error occupy considerable proportion among the railroad accidents, it is necessary to study the propriety of the physical examination system for the railroad workers. In this paper, we perform a comparative analysis of domestic and foreign physical examination systems for railroad workers. Through the comparative analysis, we suggest that test of the sleep-disorder be included in the physical examination.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.9
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• pp.759-764
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• 2014

Lateral force of wheel is important parameter when we evaluate the safety of a railway vehicle on curved track. The lateral force of wheel is influenced by the steering performance of wheelsets. Generally, in passive type vehicles, the steering performance of wheelsets is influenced by the parameters like primary spring stiffness, wheel base, conicity of the wheel profile, etc. But, the steering performance of passive type vehicle has its limit. To overcome the limit of the steering performance of passive type vehicle, active steering technology is being developed. In this paper, we analyze the lateral force of wheel and the safety of the railway vehicle on curved track by adopting the active steering technology. As results of dynamic analysis for vehicle model equipped with active steering system, the lateral force of wheel is reduced and the safety is improved remarkably.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.7
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• pp.687-693
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• 2013

The service conditions of railway cars have become more difficult in recent years due to increased speed. Faulty components in the railcars may result in service interruption, or in extreme cases, derailment. Thus, it is important to diagnose and monitor the main components of railcars. Temperature monitoring is one of the basic methods used to diagnose abnormal conditions in the main components of railway cars, such as in bearings, reduction gears, and traction motors. In this study, we developed a monitoring system for the main components, using an infrared thermography technique. This technique has the advantage of infrared thermal camera imaging of temperature contours in the components. Various hardware and software components of the monitoring system are used to acquire the sensor data, to identify potential problems in railcar operation.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.7
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• pp.673-678
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• 2013

Driving gear units can be affected by various problems, including those associated with external or internal defects in the bearing, problems with the lubricant oil, high-loading of the railway, and frequent impacts generated by rail joints. Temperature monitoring is a basic method in diagnosing abnormal conditions in the reduction gear and other components. This paper describes a new wireless monitoring system for the temperature diagnosis of abnormal conditions of the reduction gear. Integrated circuit (IC)-type temperature sensors were installed in the reduction gear box of a high-speed railway car. The temperature data from the reduction gear were acquired and analyzed in situ during high-speed rail operation. Analysis of these data was used to alert the driver and/or maintenance personnel when problems occurred.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.6
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• pp.613-620
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• 2012

Rails are subjected to damage from rolling contact fatigue, which leads to defects such as cracks. Rolling contact fatigue damages on the surface of rail such as head check, squats are one of growing problems. Another form of rail surface damage, known as "Ballast imprint" has become apparent. This form of damage is associated with ballast particles becoming trapped between the wheel and the surface of rail. These defects are still one of the key reasons for rail maintenance and replacement. In this study, we have investigated whether the ballast imprint is an initiator of head check type cracks and effect of defect size using Finite element analysis. The FE analysis were used to investigate stresses and strains in subsurface of defects according to variation of defect size. Based on loading cycles obtained from FE analysis, fatigue analysis for each point was carried out.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.7
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• pp.597-602
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• 2015

In this paper, we studied the steering performance of wheelset with primary suspension characteristics of railway vehicle. We carry out dynamic analysis and experimental study for the vehicle models which are different primary suspension characteristics. The steering angle of a vehicle model (Case 1) operating in domestic subway lines is insufficient compared with an objective steering angle for curved track. And the steering angle of a vehicle model (Case 2) with improved self-steering performance of wheelset is a little improved compare to previous vehicle model. But also Case 2 model is still insufficient compared with an objective steering angle and has its limit in steering performance. So to overcome this limit of steering performance of passive type railway vehicle, an active steering technology is being developed. In case of vehicle model with active steering system, the steering performance is improved remarkably compared to passive type vehicle model.