• Journal of the Korean Society for Railway
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• v.19 no.2
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• pp.234-242
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• 2016

In express operation plans for urban trains, it is effective for the reduction of the number of sidetracks to apply a high performance train that has improved acceleration/deceleration ability and a regular train to local and express trains, respectively. In this research, based on a plan to use a high performance train for a local train, an optimization methodology is suggested to reduce the number of sidetracks and the operation time of the local train simultaneously. The optimization solver applied in this research is a genetic algorithm; headway, location of sidetrack and waiting time at the sidetrack are considered as design variables in the optimization problem. Consequently, by applying this system to Seoul metro line no.7, the effect of the suggested methodology was verified by obtaining the proper optimum solution.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.2
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• pp.117-129
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• 2012

In this study, research was performed to establish the measurement and frequency of analysis for maintenance monitoring by investigation of tunnel maintenance monitoring system in the tunnel which was installed in the Seoul metro line 5, 7 and 8, using that the domestic and foreign application case, results of analyzed maintenance monitoring in the domestic tunnel and legal safety management standard of the facility. The results of the monitoring management about analysis frequency to the present are considered that the problem about measuring frequency does not occur. According to the analysis results of the maintenance monitoring which are located on the 5, 6th subway line, they are analyzed that the stress of concrete lining and reinforced bar are converged gradually after 45 months. Therefore Monitoring of measurement and analysis frequency is conduct more often within about 4 years after the measuring instrument installation. Four years later, slowing the frequency of measurement is considered reasonable.

• The Journal of the Convergence on Culture Technology
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• v.5 no.4
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• pp.37-41
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• 2019

The following study, as the importance of military role in a national disaster is emerging as a part of comprehensive security, there has been a number of elements of social disaster-related support in support of each type of national disaster aimed to improve the military's role towards comprehensive security but there has been no regular study of this topic. The point of this study is to analyze various aspects and hardships during the mission and improve the effectiveness of future support missions by observing and interviewing the military personnel which substituted the role of train drivers in the Seoul Metro in 2016, when the Korean Railroad Corporation [KORAIL] Workers Union was on strike [72 days] which is the longest period of a national disaster requiring military assistance.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.5
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• pp.1-17
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• 2021

Identifying the exact train and the type of train boarded by passengers is practically cumbersome. Previous studies identified the trains boarded by each passenger by matching the Automated Fare Collection (AFC) data and the train schedule diagram. However, this approach has been shown to be inefficient as the exact train boarded by a considerable number of passengers cannot be accurately determined. In this study, we demonstrate that the AFC data - diagram matching technique could not estimate 28% of the train type selected by passengers using the Seoul Metro line no.9. To obtain more accurate results, this paper developed a two-step method for estimating the train type boarded by passengers by applying the AFC data - diagram matching method followed by a mixture distribution analysis. As a result of the analysis, we derived reasonable express train use/non-use passenger classification points based on 298 origin-destination pairs that satisfied the verification criteria of this study.

• The Journal of the Convergence on Culture Technology
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• v.4 no.4
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• pp.413-418
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• 2018

The purpose of this study is to investigate the cause of rail corrugation and the track force for concrete track (STEDEF) in the urban transit. From the field measurements, the dynamic wheel load, vertical displacement of sleeper and rail bending stress were measured and it was evaluated by regarding to the rail corrugation. As a result of the study, the causes of rail corrugation was experimentally proved by frequency analysis using measured dynamic wheel load data. The influence of corrugation on dynamic wheel load, rail bending stress and sleeper displacement was evaluated that the periodic irregularities of rail corrugation on the rail surface amplified the dynamic track force such as the dynamic wheel load, and thus the rail bending stress and the vertical displacement of sleeper could be increased by a maximum of 1.7 times.

• The Journal of the Convergence on Culture Technology
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• v.5 no.1
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• pp.389-394
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• 2019

In case of damaged timber sleepers, maintenance is carried out according to the track inspection standard. However, it is difficult to detect the extent of damage on the bridge, and maintenance is depended on inspector's judgment. In this study, we propose to improve the evaluation criterion of timber sleepers for the ballast-less tracks on serviced urban railway bridge. The timber sleepers on railway bridge was classified according to degree of damage, and damage scores were calculated for each damage grade. Also we have improved the maintenance system of the timber sleepers through the history management system of the individual timber sleepers on railway bridge. As a results, it was judged that systematic management of timber sleepers could be possible during maintenance.

• Journal of The Korean Society For Urban Railway
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• v.6 no.4
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• pp.427-436
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• 2018

HADAX is a serial communication converter of train control computer. It is connected with various signal equipments such as wayside signal equipments, station signal equipments, train control computers, and transmits control information and signal condition information for train control. And transmits information to several electronic interlocking devices through a splitter interface. Since HADAX interfaces with many signaling devices through serial communication, frequent communication connection faults necessitate improvement of performance such as dual system configuration, integration of external splitter, and multi-channelization of communication card. The improved HADAX device should have compatibility with the dimensions of existing enclosure and enclosure, and verify the performance of dual system and splitter integration. Therefore, we verified the performance of HADAX through the route control test, dual system test, and multi-channel communication test with splitter integrated connection by connecting with the existing signal equipment.

• The Journal of the Convergence on Culture Technology
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• v.7 no.3
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• pp.517-522
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• 2021

In this study, the causes of damage to the concrete sleepers in a ballast track with under sleeper pads attached to the base of the sleepers installed in the sharp curved track(R=180m) of the urban railway bridge were analyzed. The damage types of concrete sleepers were investigated, and the correlation with track irregularity was reviewed. Also, stress generated in the concrete sleeper was reviewed through structural analysis. As a result, most of the cracks of the sleepers occurred in the section with severe track irregularity. In addition, as a result of the analysis, the stress generated in the track components and the sleepers was found to be reduce in the fastening system using the 4-anchor.

• The Journal of the Convergence on Culture Technology
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• v.8 no.4
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• pp.407-413
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• 2022

In this study, the empirical formula for evaluating cable tension based on long-term measurement for about 3 years according to temperature change was proposed by proving the correlation between the expansion joint displacement of the upper road bridge and the cable tension of the lower railway bridge. The tension prediction results using the empirical formula for tension evaluation each cables proposed in this study were found to be in good agreement with the cable tension using the vibration method within 3%. Therefore, it was analyzed that it could be applied together with the vibration method that was an experimental technique, to predict and evaluate the cable tension in serviced railway steel composite bridge. As a result of applying the estimated temperature calculated by the empirical formula for expansion proposed in this study to the empirical formula, it was analyzed that a high level of reliability could be secured when compared with the vibration method. Therefore, it is judged that the empirical formula for cable tension evaluation reflecting the estimated temperature proposed in this study can be used to predict the tension of cables according to climate change in the future and establish a maintenance plan.

• The Journal of the Convergence on Culture Technology
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• v.8 no.3
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• pp.265-270
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• 2022

The purpose of this study is to derive the damage weak part of the elastic rail fastening system for concrete tracks (System 300-1). In the concrete tracks, the elastic rail fastening system sticks the rail and the sleeper and reacts all the time when the train is running. Among the components of the rail fastening system, the resilience pad and tension clamp were fatigue members and were constantly deformed in response to compressive and uplift forces. In this study, the residual deformation characteristics of the tension clamp according to the period of use were analyzed using by specimens taken on site in the same section for 6, 11, and 16 years on the serviced urban transit. In addition, the damage mechanisms for each component were derived based on finite element analysis. As a result of the numerical analysis, the stress (strain) of each part of the tension clamp according to the external force from the applied clamping force was analyzed to derive the damaged weak part of the tension clamp.