• Journal of the Korean Society for Railway
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• v.14 no.4
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• pp.364-369
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• 2011

For the safety management of tunnel, effective measurements should be continuously carried out. Most of sensors currently being applied for tunnels measure only the local status, thus many of them are needed to monitor an entire tunnel. For the railway tunnel where trains of same conditions are regularly operated, dynamic responses of tunnel structure to train operations can be a good index to estimate the deformation of tunnel structure in wide area. Meanwhile, the electromagnetic interference caused by overhead centenary in railway tunnel obstructs the use of electric-based sensors. In this study a brand new accelerometer using FBG optical fiber sensors is developed to solve these problems. Sensitivity and capacity of the accelerometer are enhanced with effective structural design of its components and verified with laboratory tests. A case history where the developed accelerometers were applied to a safety monitoring system of a high-speed train tunnel is presented. The performances of the developed accelerometers are validated from the measured acceleration data.

• Journal of the Korean Society for Railway
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• v.17 no.6
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• pp.457-465
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• 2014

This study proposes a policy for urban railway travel demand management system in order to decrease the load factor of the Seoul metro Circle line, particularly for the segment between Sadang and Samsung stations, through analyzing the transit smart card data. We propose mixed train operations of the existing Circle line and a line that goes toward Samsung station in order to transport passengers that have two distinct groups: those with the destination of Samsung station and those with destinations after Samsung station. The introduction of a mixed train operation that encourages passengers passing through Samsung station to take a Circle line train will decrease the congested load factor by 11.3% during the morning peak hours using the mixed train operation of the Circle and Samsung lines. This policy could be an effective method to decrease the load factor and improve the comfort of rail passengers without extra investment in the railway facilities.

• Journal of Distribution Science
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• v.4 no.1
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• pp.53-78
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• 2006

We call this world network society. Logistics is one of important network systems which connect people, materials and information. The World Economy Conditions of 21st Century has been Changed so rapidly. These Changes are more conspicuous in Northeast Asia than other Regions. China, North Korea and Russia have reformed their Economical and Social Systems, which enlarged the Trade Volume and Traffic Demand in this Area and between Europe. The Railway System Crossing the Eurasia Continent, such as TSR(Trans Siberian Railway), TCR(Trans China Railway), TMR(Trans Manchuria Railway), TMGR(Trans Mongolia Railway) and TKR(Trans Korea Railway), have been becoming very important to enhance the International Transportation efficiency and to connect each continents by International Railways. This Paper investigated and surveyed the logistical Environments surrounding this Korea Peninsula. And concerned with the Crossing Continents Railway, TSR,TCR(TMR, TMGR), TKR, operating Conditions and Tasks that must be considered and solved were also investigated. Especially the Current Logistical Conditions of China, Russia, and North Korea and their Problems were surveyed. And the SWOT of these Railways were analyzed and compared. The Visions and Goals of these Inter-Continental Railways were suggested in terms of their Rationalization of Operations and efficient Connections among many Countries. Not only the Policies and Strategies/Tactics which should be considered but also and Many detail countermeasures which should be introduced and adopted were suggested.

• Journal of the Korean Society for Railway
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• v.20 no.4
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• pp.491-499
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• 2017

Railway turnout systems are one of the most important systems in a railway and abnormal turnout systems can cause serious accidents. To detect an abnormal state of a turnout, turnout clearance detectors are widely used. These devices consider a failure of a turnout clearance detectors to be a failure of the turnout system, that could hinder train operations. Analysis of turnout clearance detector failures is very important to ensure normal train operation. We categorized failures of detectors into four groups to identify failure characteristics of the 140 detectors, which are composed of main line detectors (A), side tracks (B), detectors that are in operation more than 80 times a day (C) and detectors that are in operation fewer than 10 times per day. Failures of detectors have mainly been caused in the control part, in the cables and sensors; failures are classified into four groups (A, B, C and D). We have tried to find failure density distributions for each type of failures, inferring the parameter distributions a priori. Finally, using the Bayesian inference we proposed a maintenance time for control parts through the mean time of the detector, life and the life expectancy.

• Journal of the Korean Operations Research and Management Science Society
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• v.30 no.2
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• pp.41-61
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• 2005

The concept of revenue management (RM) has been used widely in the air-transportation industry, and proven as a good system for managing perishable assets. While the airlines are the oldest and most sophisticated users of RM, these practices have been an enormously important innovation in other service industries such as the travel, the railway, the internet and the manufacturing industries. In this paper, reviewing several studies on RM, we introduce the fundamental concepts and the major models of RM covering seat allocation with multiple fare classes and overbooking. Future research directions also are suggested.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.299-304
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• 2008

Catenary and Pantograph are a power supply devices for electric trains and shall be steadily contacted. Rail catenary must be installed precisely and managed for stable train operations. But external factors such as weathers, nature, etc., or aging affect catenary geometry. Changed catenary height causes high voltage spark or instant electric disconnection. Big spark and disconnection damage pantograph shoe and catenary coating and might interrupt rail operations. To prevent a big scale spark or electric disconnection catenary maintenance shall be required with catenary geometry measurement systems. In this paper, we describe the development of catenary height and stagger measurement system. The catenary height and stagger measurement system uses Acuity company's AR4000 Range Finder for distance measurement and AccuRange Line Scanner for degree measurement. This system reports suspicious overhead line sections with excessive height and stagger variance.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.606-615
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• 2006

This study identifies the comparison of Technical specification and Characteristics of DC Protection Relay(ETCPU200) used in DC Distribution System in Korea. ETCPU200 has completed Field Test and approved its capability by finding out causes of recent operations through lately developed digital DC protection relay in parallel operation at Maebong-Substation, Nakseongdae-Substation, Euljirosaga-Substation, Jegi-Substation and Chongryangri T/P area. It also examines additional features for efficient System Analysis and Operations.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.24-31
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• 2000

This paper evaluates the efficiency of Korea National Railroad on the basis of revenues from 1980 to 1999. There was a significant inefficiency in this organization due to operating at an decreasing return to scale area. Although Korean Railroad in 1990s has made a great effort, his performance is still low. Consequently, it is important to insure substantiality of operations than to expand business area in order to finally improve the efficiency, in particular the revenue efficiency, of the Korea Railroad.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.237-244
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• 2005

The Auxiliary Inverter supply the power to Loads of Electric Locomotive. The Auxiliary Inverter have three characteristics. First, The Auxiliary Inverter is VVVF(variable voltage variable frequency) inverter. And, the output voltage is AC $0^{\sim}440V$. Second, The Auxiliary Inverter is controled all operations by CCU(Center Control Unit). Last, The Auxiliary Inverter have the SIBMON program. This program easily displays most of all status of auxiliary inverter.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1279-1284
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• 2008

This paper presents the operating characteristic of high voltage impulse(HVI) track circuit owing to the ill-contact of impedance bond lead wire. The characteristic operations of the track include rail voltage and current. Measurements are carried out using oscilloscope with current probe and it analyzed the abnormal operation due to connector of protective wire. Finally, suitable track circuit is proposed for conventional line, and operating characteristic of HVI track circuit is affected by bypass circuit.