• Proceedings of the KSR Conference
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• 2006.11b
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• pp.646-658
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• 2006

In this paper, the details of electric traction voltages which are widely used for metro and mainline trains are presented. The problems encountered in catenaries, pressure of the pantograph pan, catenary contact cross sectional area, materials etc are well covered. Catenary height from the rail for main line, bridges, sheds etc is discussed. The catenary running details and switching of one catenary to another are explained. The dead zones in 3 phase grid as well as in DC are presented here. The pantograph structure, blades, shoes etc. for AC/DC EMUs are dealt. The schematic diagram for electrification systems used for railways are given and explained with typical electrical parameters of Indian Railways.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.6
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• pp.500-506
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• 1999

This paper presents the h밍h performance [GBT type auxiliary jXlWer supply designt.'Cl by new concept. For t the simplification and higher performance, the direct :3 level PWlVl inverter using the high capacity IGBT and t the 32bit DSP are adopted. The cost as well as bulk and weight is appreciably reduced about 40% lower than t those of conventional one. the electrical efficiency above 94~) o and the audible noise level is less than 65dB. In a addition, the TIID(Total lIannonic Distortion) factor is below 5% an이 the voltage fluctuation on a transient s state is below 10%.w 10%.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.673-678
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• 2008

In crushed service areas of Metro railway lines, there are problems such as the buildup discontent, the irregular operation time and rotation of rolling stocks, caused by frequently occurred train delay. Train delay is affected by operation conditions or infrastructure capacities such as train schedule, line capacity, car rotation plan, shunting movements at origin and destination, and also by transport demand characteristics. Furthermore, a delay produce another delays and spread over the following trains. So it is not easy to build up a protection and recovery plan. In this research, we conduct experimental analysis study based on the real metro data, and as a result, present the relation between the traffic demand and the dwell time. And finally, propose future research themes for improving the operation efficiency of metro railways.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.732-741
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• 2008

After freight train line opening between Munsan of South Korea and Bongdong of North Korea last December 2007, people's expectation and interest about trans North-South and continental railways have been increasing. However, the commercial traffic of freight by train has not been increased as much as we expected in the mean time road traffic is more increased. This study examined the Kaesong industrial complex which has a high rail accessibility. Especially, we interviewed the owners of enterprises in Kaesong to integrate their opinions for deriving the problems and improving the business conditions. Also, this study embodied the methods for improving rail freight traffic between North and South Korea. Based on this study, we expect more research will carry out on this field to reform the operation system of trans Korea railways by Kaesong industrial complex development project and the commercial reconversion from road to rail.

• Proceedings of the KOR-KST Conference
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• 2007.11a
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• pp.888-894
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• 2007

• Magazine of the Korea Concrete Institute
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• v.26 no.1
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• pp.41-45
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• 2014

• Proceedings of the Korean Geotechical Society Conference
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• 1996.10a
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• pp.3-24
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• 1996

• Journal of the Korean Institute of Gas
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• v.10 no.3 s.32
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• pp.41-47
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• 2006

When an underground pipeline runs parallel with DC electric railways, it suffers from electrolytic corrosion caused by the stray current leaked from the railway negative returns, i.e., the rails. Perforation due to the electrolytic corrosion may bring about large-scale accidents even under cathodically protected condition. Traditionally, drainage bonding methods have been widely used as a mitigation method for stray current interference. In particular, the increased adoption of forced drainage method to gas pipelines makes the interference much more sophisticated. In this paper, we analyze the electric interference between pipelines and railways from the results of field investigation carried out in Seoul and Busan.

• Journal of the Korean GEO-environmental Society
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• v.18 no.12
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• pp.13-23
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• 2017

This paper discusses about the reinforcement materials and construction method in order to cope with roadbed settlement in operating railway. In Korea, concrete tracks have been introduced to urban railways, high-speed railways, and general railways, but some recently constructed concrete tracks have experienced roadbed settlements. Reinforcement of the railway roadbed is urgent task for safe operation of railway, but it is difficult to reinforce the roadbed and there are no case history of reinforcing railway roadbed under an operating railroad track. Therefore, in this study, the target performance level for roadbed reinforcement was determined, and infiltration and solidity injection efficiency were investigated for selected reinforcement materials. As a result of the study, it was found that the generally used reinforcement materials and methods for geotechnical works need to be improved for applying in railway roadbed reinforcement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.15-20
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• 2019

This paper evaluated the construction costs of 11 design cases to decrease the horizontal forces applied to the abutment. They include two abutment types, which are to improve backfill materials for a reversed T-shaped abutment and geosynthetic Reinforced Abutment for Railways (RAR). The first type of economic analysis was that the internal friction angles of backfill materials were increased from Φ=35° to Φ=40° and 50° for a reversed T-shaped abutment. In addition, the second type was the cases with the design of geosynthetic RAR. When friction angles of 40° or 50° were applied through the improvement of the backfill material, the decrease in construction cost of the abutment was not large (2.0~3.9%), even though the horizontal forces applied to the abutment had decreased to 18~48%. In the case of applying the RAR, however, a maximum 30% cost reduction was evaluated by the decrease in horizontal force to "0" theoretically. The cost reduction resulted from the decrease in wall thickness, base slab size, and number and material change of pile foundation for the abutment.