• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.9
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• pp.1343-1347
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• 2013

This paper presents an analysis methods for current collection quality in catenary system by means of video image based monitoring system. Arcing is the sparking at the interface point between pantograph and contact wire when the electric trains have traction current values at speed. Percentage of arcing at maximum line speed is measurable parameters for compliance with the requirements on dynamic behaviour of the interface between pantograph and contact wire in accordance with requirement of IEC and EN standards. The arc detector and video is installed on a train aim at the trailing contact strip according to the travel direction. The arc detector presented and measured verity of value such as the duration and power density of each arc and the video image is measured a image when the arc is occurred in pantograph. In this paper we analysis of video image in accordance with power density of arcing from arc detector and compared with video image and power density of arcing so as to produce quality of arcing from image.

• Journal of the Korean Society for Railway
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• v.20 no.3
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• pp.349-355
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• 2017

Failures of railway systems can result in train delays or accidents, and therefore high reliability is required to ensure safety of railway systems. To improve reliability, railway systems are designed with redundant systems so that the standby system will continue to function normally even if the primary system fails. Generally, overall system reliability can be evaluated by the reliabilities of the parts of the whole system and the reliability of the redundant system considering common failures in case of each system is not conform physical, functional and process independent. In this study, the reliability of the hot-standby sparing system is analyzed the independent systems and dependent systems with common failures. The reliability for the standby system can be effectively analysed using Markov models, which can model the redundant configuration and the state transition.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.7
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• pp.619-625
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• 2015

There is a large interest to find reliable and automatic methods for crack detection and quantification in the railway bogie frame. The non-destructive inspection of railway bogie frame has been performed by ultrasonic and magnetic particle testing in general inspection. The magnetic particle method has been utilized in the defect inspection of the bogie frame but the grinding process is required before inspection and the dust is developed resulting from the processing. The objective of this paper is to apply the inspection method of bogie frame using infra-red thermography. The infra-red thermography system using the excitation of eddy current was performed for the defect evaluation of weld specimen inserted artificial defects. The result shows that the infra-red thermography method can detect the surface and inner defects in weld specimen for bogie frame.

• Journal of the Korean Society for Railway
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• v.17 no.2
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• pp.106-113
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• 2014

In this study, a practical evaluation technique to detect the deterioration of railroad lines by means of train performance and track geometry measures is suggested. A train that has a specific performance and is running the straight line can make minimum travel time (ideal time). But the actual travel time will be increased by the track geometry and various speed limitations. By comparing these travel times, we can easily define the degree of line deterioration. This method does not require complex vehicle performance measures and/or specifications that exceed those of typical Train Performance Simulations (TPS). For this reason, ease of use is ensured and the results are similar to those obtained by running a TPS for practical evaluations.

• Journal of the Korean Society of Systems Engineering
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• v.8 no.2
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• pp.11-17
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• 2012

Suppliers in light rail transit project makes a systems engineering management plan(SEMP) as a top level plan which has a SEMS and SEDS as an control and monitoring means. In this paper, we analyze the international standards and some related documents, and present the directions to make the SEMS and SEDS which have WBS, accomplishments, schedule, events, person in charge. And then customize the project management tool and make SEMS and SEDS of LRT project as an example. The research results can be applied in LRT project after tailoring based on the project.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.10
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• pp.1069-1077
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• 2015

In tunnel excavation using blast, the wire saw rock cutting method generates a discontinuity perimeter around the center cut, and thus prevents blast vibration propagation to reduce vibration and noise. Therefore, the method is expected to be easy to use and economical compared with other methods. In this paper, the cutting mechanism of wire saw in tunnel excavation is investigated. A model describing the changes in cutting depth and wire saw shape inside a rock during cutting is established and validated for this purpose. Through a simulation using the model, the important characteristics of wire saw cut are investigated, and the influences of cutting conditions, such as wire saw tension, wire saw speed, feed speed, depth, and diameter of boring, on cutting performance are also examined. A method to improve the cutting performance is proposed based on the results.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.523-531
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• 2007

The research for the improvement of the aptitude test system in the field of railroad is progressing actively in advanced countries. Our government is also promoting some systematic supplementation for railroad safety on the basis of the Railroad Safety Act. In this paper, we focus our attention on an improvement of the present aptitude test system which will lead to the improvement of the safety supervision of Korean railroad. For this purpose, we perform a comparative analysis of domestic and foreign aptitude test systems for train drivers. We provide useful information that is needed to derive desirable aptitude test systems.

• Journal of the Korean Society for Railway
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• v.6 no.1
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• pp.73-79
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• 2003

The Korean high speed railroad is scheduled to open in 2004. For railroad-based integrated transfer system, it is essential to develop the intermodal information system for easy transfer to other travel modes. The understanding of mode choices by KTX passengers is crucial for the intermodal transportation planning. Recent development of Intelligent Transportation Systems(ITS) made it possible for railroad users to access the transportation information in a cabin or waiting areas at the station. Development of intermodal transportation information system will influence the relative demand for traveling by train from competing other transportation modes. The research is focused on a general overview of the ITS with an emphasis on intermodal transportation information system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.6
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• pp.881-885
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• 2013

In this paper, we present a deterioration judgment model of urban rail power equipment using driving history, the frequency and number of failures. In addition, we have developed a deterioration judgment program based on the derived failure rate. A deterioration judgment model of power equipments on metro system was designed to establish how much environmental factors, such as thermal cycling, humidity, overvoltage and partial discharge. The deterioration rate of the transformers followed the Arrhenius log life versus reciprocal Kelvin temperature (hotspot temperature) relation. The deterioration judgment program is linked to the online condition monitoring system of urban railway system. The deterioration judgment program is based on the user interface it is possible to apply immediately to the urban rail power equipment.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.307-313
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• 2002

Due to the fact that high speed railroad will be opened to traffic and TSR and TCR will be connected to Korean railroad network in near future, the efficient operation methods of Railroad freight transportation have been embossed as a matter of concern. But, it is true that the present level of our railway infrastructures and operation systems are still low. This study examines the freight transportation system and introduces new logistic service systems including network strategies and terminals which are haying developed overseas to increase the efficiency of existing railroad transportation system. In case of giving careful consideration to the new methods, it is expected that the high developed freight transportation systems will be applicable to our country.