• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1694-1714
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• 2007

This study is to estimate economic benefits of Standardization R&D of Urban Rail System. Benefit was to be realized through standardization of main areas such as train vehicle, railway, power system, and signal system. To derive and calculate the quantitative benefit, the sources of economic impact was divided into three dimensions -operational cost savings, import substitution, and safety effects. Economic effect of the standardization was categorized based on a modified BSC model. Economic benefits from time and labor savings are converted into cost savings. Import substitution and investment multiplier effect have a positive impact in addition to cost savings. The estimation of the standardization R&D of Urban Rail System was conservatively estimated 370 billion Won. Cost effectiveness of standardized safety system was conservatively translated into economic benefit in this analysis. This study provides a practical guide to economic evaluation of the various railway R&D projects.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1466-1472
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• 2007

State estimation is to estimate the values of the states that minimize the error between the real states and the measured states, which are usually hampered by noise. It exploits the redundant data and the equality constraints achieved from the power systems. In the electric railway feeding systems, especially, the measured states may have significant level of noise in comparison with the commercial power systems. Since the meters - the sources of the data that include vehicles - are distributed in the long distance along the railroad, they are vulnerable to the signal interference. In this paper we have studied the application of state estimation method to the AT feeding systems and shown that this method can increase the reliability of the measured data.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.2
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• pp.102-106
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• 2014

Energy saving is as important as developments of green energy and alternative energy. The need for development of high-efficiency lighting apparatus further increased. This paper compared with the size of electrical equipment and analyzed the size of electrical capacity for the railway station building. Also discussed energy saving measures that can be achieved by using high-efficacy lighting fixtures, and the percentage of the lighting load capacity of the entire building.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.3
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• pp.294-300
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• 2009

In high speed railway bridges, dynamic analysis is important because of high passing velocity and moving load at the regular intervals, and damping ratio is a major parameter to predict dynamic responses. In this paper, damping ratios were estimated by using half power band width method and extended Kalman filter according to acceleration signal conditions, and a relationship between estimated damping ratios and representative values of bridge vibration was derived. From the results, damping ratios estimated from total ambient vibration were more reliable than only free vibration part. In case of using extended Kalman filter, the estimated damping ratios varying with RMQ(root mean quad), as one of representative values of bridge vibration, have more feasible trend. Thus, it is shown that further studies on reliabilities of estimated damping ratios are needed.

• Journal of the Korean Society for Railway
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• v.6 no.4
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• pp.232-238
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• 2003

A health monitoring system becomes a very useful tool to obtain information on long term behavior of the important railway structures such as very long span and special type bridges. It can be also used to give a warning signal to the maintenance engineer when the structure shows abnormal behavior. However, due to long term use and temperature changes, the health monitoring system needs to be calibrated periodically. In this study, calibration and gauge factor readjustment process made for the health monitoring system installed in the railroad bridges and tunnel are reviewed and a few findings are updated. Future work will be concentrated on the long-term analysis of the measurement data and on the database structures so that the assessment of the structure is possible

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.427-435
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• 1998

In this paper will be presented an algorithm for designing of a railway interlocking table which is a document describing the functional specification of the interlocking device. The ability to produce an interlocking table has been handed down in the signalling engineers society. And the signalling engineer makes the most of his expertise to produce an interlocking table. But, the expertise has not yet been organized into technical system, the core of the expertise is a hard nut to crack. Therefore, we analyze into signal engineering expertise, and propose a generalization of interlocking notion. Also, an algorithm is drawn up based on a train route setting principle to solve practical and general problems by computer And the performance of the algorithm is evaluated for test program based on AutoCAD technology. The evaluation result shows that it can be utilized as the effective algorithm for computer control of the signalling system as interlocking device, that it improved in safety

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1451-1453
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• 2000

The automatic/driverless operation which are great important techniques in metro railway are required to increase higher safety, greater reliability, and transport capacity. To satisfy such demands, we must have the system design and testing technique for the railway system operation. These techniques are related to the onboard train control and communication systems which include TCMS(Train Control and Monitoring System), ATO(Automatic train Operation), ATC(Automatic train Control), and TWC(Train to wayside communication). These sub-systems must be interfacing with not only each others but also the signal system on the ground. We tested the train control system on the 7 line that has been developed on the basis of the standardized type EMU for korea railway systems.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.3-7
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• 2003

The dynamics of the pantograph motion and contact forces of the high-speed railway are investigated through signals. acquired during a test run. The signals are obtained from accelerometers, load cells, and strain gauges attached to various positions of the pantograph, and they are processed in time-and frequency-domains to evaluate the dynamic characteristics and load forces. The natural frequencies of the pantograph is found to be 8.5Hz. There also are frequency components varying linearly with the train speed. The signal frequency components above 40Hz are attenuated as they pass through the primary and secondary suspensions.

• Multiscale and Multiphysics Mechanics
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• v.1 no.3
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• pp.261-270
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• 2016

The longitudinal velocity (forward speed) having significant importance in proper running of railway wheelset on track, depends greatly upon the adhesion ratio and creep analysis by implementation of suitable dynamic system on contamination. The wet track condition causes slip and slide of vehicle on railway tracking, whereas high speed may also increase slip and skidding to severe wear and deterioration of mechanical parts. The basic aim of this research is to design appropriate model aimed estimator that can be used to control railway vehicle forward velocity to avoid slip. For the filtration of disturbance procured during running of vehicle, the kalman filter is applied to estimate the actual signal on preferered samples of creep co-efficient for observing the applied attitude of noise. Thus error level is detected on higher and lower co-efficient of creep to analyze adhesion to avoid slip and sliding. The skidding is usually occurred due to higher forward speed owing to procured disturbance. This paper guides to minimize the noise and error based upon creep coefficient.

• Journal of the Korean Society for Railway
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• v.7 no.3
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• pp.232-238
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• 2004

The dynamic characteristics of the current collection process of the high-speed railway are investigated through signals acquired during a test run. The signals are obtained from accelerometers, load cells, and strain gauges attached to various positions of the pantograph, and they are processed in time-and frequency-domains to obtain the dynamic characteristics. The main natural frequency of the pantograph is found to be 8.5Hz. There also are components at low frequencies varying linearly with the train speed. The contact frequency components above 20Hz is attenuated as they pass through the secondary suspension. The main frequency component of the load cell signal is found to be related with the rolling motion of the panhead generated by the stagger in the catenary.