• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.436-439
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• 1999

This paper present a study on the interference levels on the communication lines, which are parallel to the electrified rails. The interference study is carried out using a circuit model approach. First, the self and shunt impedances of all the conductors in the rail system and the mutual impedances between different conductors are computed. Several different scenarios are analyzed, including the load condition and a few fault conditions with different fault locations. The induced potentials on the communication cables are computed. The effect of the buried ground wires is also analyzed by comparing the results with and without the presence of the ground wires. The results presented in the paper can be used as a reference for estimating interference levels in similar rail systems.

• Journal of the Korea Safety Management & Science
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• v.12 no.3
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• pp.163-168
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• 2010

Recently, there are many problems of service qualities such as regular-rapid-safe -comfortable transport, that was traditionally advantages in urban railway transportations. These problems cause train delays that affects consecutive schedule, capacity, operation plans, and it is hard to prevent the propagation of delay and find the recovery solution. Because the urban transport demands is continuously increased and the railway service is also expanded, the railway operation company makes efforts to improve operation performance and efficiency for passengers. In this paper, we analyse the issues and problems existing in the major operation line of high-density urban railways, and suggest the development direction of intelligent operation technology to improve the urban railway service by minimizing the occurrence and propagation of delay. And the result of numerical case study is also presented.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.165-175
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• 2003

Railway route maps including subways is a guide map which offers transport information as well as cartographic diagrams and is not only a way of communication, but it should give also concrete image and pleasing form. The elements of route map should meet satisfaction requirement condition and design attributes with aesthetic principles. To guide passengers by giving geographic information effectively, we need to understanding the following concepts and its application of basic elements such as expressing its structure and value. Therefore it should appear as a diagram with typography, form, symbols and colour. This means the aim of a good visualization should be done by a method that is concrete and a synthesis of well composed elements.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.768-773
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• 2003

The inspection of track irregularity, which is the most important index for the evaluation of the dynamic safety of the rolling stock, is performed by setting up the testing train set. The self-diagnosis for the various rolling stocks and railways can be obtained if it is possible to take the simultaneous inspection of track irregularity for the commercial vehicle while it is running and to build up a dynamic safety evaluation system. It is expected to have some good effects, such as preventing accident with the low dynamic safety, cutting cost for the testing train set and evaluating the exact influence on the rolling stock and railway. In this study, innertial measuring method, which allows us to directly measure the track irregularity from the commercial vehicle, will be considered and some overseas cases will be explored as well.

• Proceedings of the KSR Conference
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• 2002.05a
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• pp.590-596
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• 2002

Contact wires are made by metallic materials and exposured at atmosphere. We have investigated mechanical properties and the present condition of air pollution as to the messenger wires and ACSR wires of these contact wires. Mechanical properties between new contact wires and used, the used one's tensile strength and elongations was decreased by effect from corrosion. We observed a fatigue properties which was investigated by fatigue test because contact wires were affected with amplitude vibration everytime the train passed through the railways. In the evaluation of fatigue test, it was also shown that fatigue life of the used wires was decreased 50 ∼ 60% compared with that of new ones in average by effect from corrosion.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.724-729
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• 2005

Winter weather condition can cause icing and ice coats on 25 kV overhead contact wire. This generates shocks at the mechanical interface of the collecting strips of the pantograph and the contact wire and extra electrical resistance, which may affect quality of current collection at the contact wire / collecting strips of pantograph interface. De-icing operations should he performed just before train operation to avoid the formation of another ice layer. Thus, the work in this paper is investigation and analysis of de-icing system which could be applied to the electric car line of railways.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.152-157
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• 2005

Recently, higher speeds have been promoted in old overhead-lines. For high-speed operation in electric railways, increasing contact loss of the pantograph is one of the most important subjects. The contact loss causes power interruption and increases wear of contact strips and contact wires. In order to investigate the causes of contact loss and to work out effective improvement methods, theoretical analyses, experiments have been carried out. First of all, the wave propagating velocity (phase velocity) and characteristics of contact wire are one of the important indices for the current collecting performance. In this paper, mathematical formula arc derived for the prediction of the traveling wave velocity. The measured values in the experiment agree well with the theoretical predictions.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.203-210
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• 2005

Rockey slopes adjacent to railways are disclosed from severe weathering and hazard of failure of themselves. Consequently it causes directly rockfall or landsliding on the railway. Conventional solutions-rigid system like rocksheds, shotcrete, retaining walls, etc to these causes are limited to protect train, rail, our properties and lives from the harmful attack - rockfall. debris flow and sliding. Flexible concept for solutions with passive and active type method based on Euro Code 7 capable of high energy absorption and light materials are rapidly replacing the rigid systems with natural friendly, early installation, cost and time saving and reducing danger in works all over the world.

• Proceedings of the KSR Conference
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• 2002.05a
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• pp.41-46
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• 2002

This paper deals with the exchange of tourists and the operation of sightseeing train encouraged by the inter- Korean cross-border railway project. First of all, how the inter-Korean cross-border railway project has developed will be discussed. After this, tile present tourism state, facilities, the state of railways and roads of North Korea, and major tourist attraction around the Kyonguisun will be shown. And then, several aspects on the agreements between the Korean National Railroad (KORAIL) and North Korean railroad system will be summarized. And, finally, the economic effect of the line including the operation schedule of the Kyonguisun sightseeing train, the demand forecast, the computation of railway fare, and profit sharing will be depicted.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.823-829
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• 2005

The extent of slack is correlative with the wheelbase of vehicle as well as the distance between the inner faces of flanges. Since the movable clearance of wheel flange is getting reduced in curved track, the vehicle is more difficult to negotiate the track. By this reason, a certain extent of slack is normally designed for curved track to allow the movable clearance corresponding to that of straight track. In case of some foreign railways,. the fixed extent of slack has been classified by the ranges of curve radius. In case of KNR, the slack is calculated by a formula for each case of curve radius and it therefore seems quite precise method. However, since there is a wide range of slack adjustment $(S'=0\~15mm)$ in calculation formula itself, too excessive or too little slack can be calculated. This study is to approach the technical review on slack calculation and to offer the reasonable slack design through the full-scale experiment at sharp curved track without slack.