• Journal of Korea Port Economic Association
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• v.28 no.3
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• pp.215-234
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• 2012

Since ports play a role of gateway to the sea and hinterlands, it is essential to analyse the networks of shipping and inland when evaluating the function and development of a port. The container port of Gwangyang, starting to operate its facilities in 1998, has developed itself as a hub port. Using the data of shipping schedules of Korean ports and the measurement of centrality in sociology, this study analyses the process of world-wide shipping network expansion in Gwangyang and concludes some implications including earlier development of shipping networks due to incentives to shipping companies. Although Gwangyang port also has been expanding its inland network through developing trucking, railway transport, and coastal shipping, it has weakness in inland network as in the cases of interruption in 2004, resumption in 2009 and re-interruption in 2012 at coastal shipping. In 2000s the expansion of shipping and inland networks at the newly built container ports such as Pyungtaek, Ulsan, and Gunsan has enticed the competition among Korean ports at each hinterland. Nevertheless, the operation of Gwangyang container port is considered to affect indirectly the relocation of some manufacturers including Samsung Electronics. Studies on interrelation between development of container port and geographical demography of manufacturers are needed to assess the effects of container port on regional economy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.6214-6220
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• 2015

A track circuit has used stably more than 100 years for detecting train position, but solution of track circuit sort circuit incapacity due to a rust is necessary for side line in station yard, coast line and level crossing for conventional line in rural line. Domestically, Axle Counter System(ACS) has partially used for Hot Box System for high speed line and turnout for CBTC system. In contrast, most of countries has used ACS not only trunk line but also rural line and its application has increased for metro, electric car and industrial railway. In this paper, we has verified the operating status of ACS which installed with existing track circuit through log analsis to implement pilot application in mail track and turnout in station yard. And interface test with interlocking system has conducted at Obong shunting yard, as well as Cheongju station and has analyzed test result. Based on a test result, we made fail safe design, manufacturing skill and established system requirement specification for the smooth operation and maintenance.

• Journal of Practical Engineering Education
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• v.8 no.2
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• pp.103-109
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• 2016

In order to get the maintenance work for the normal operation of rail vehicles made safe maintenance training, which looked suffered direct physical train maintenance environment, gain experience to get out foster the practical skills, but experience the real maintenance in operational problems the maintenance procedures followed are difficult to be. So it can gain experience and knowledge of the actual maintenance work in safe conditions if you apply a simulation experience in a similar environment as possible to the actual train maintenance training can also reduce operational training costs. For a description of the current domestic and simulation programs of the railway sector it has been operating in overseas and is designed to train intensive training, maintenance and maintenance-related information is scarce situation. In this study, the contents of the theory of educational technology for effective training of train maintenance elements exhibit theory, theory of learning situations, designed to train maintenance training simulation through a previous study that investigated the problem-based learning theory.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.6_spc
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• pp.644-650
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• 2016

Track maintenance works based on track geometry recordings are essential to enhance the safety and comfort of railway transportation. Usually, the track irregularity has been measured by a special inspection trains which all were imported from abroad. Because the inspection train speed is limited under 160 km/h, it takes a long time to inspect railways and there is difficulty in daytime operation. To solve this problem, we started to develop a track geometry measuring system (TGMS) with measurement speed up to 300 km/h which can be installed in commercial vehicles such as HEMU-430X. In this paper, we introduce a newly developed inertial TGMS and propose two inertial navigation system (INS) algorithms (method A, B) for measuring track geometry. In order to investigate advantage and disadvantage of each algorithm, we performed vibration test of the TGMS, which was simulated by 6-axis shaking table. Through the vibration test, we analyzed the influence of vehicle vibration on the TGMS which will be installed on bogie frame. To the vibration test, two methods satisfied the required accuracy of track geometry measurement under the level of the actual vehicle vibration of HEMU-430X train. Theoretically, method A is sensitive to vehicle vibration than method B. However, HEMU-430X's bogie vibration frequency range is out of interest range of measurement system. Therefore, method A can also apply the HEMU-430X train.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1204-1212
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• 2008

This study enables to troubleshoot the problems of the existing dual system with the help of the implementation of totally dualized fault-tolerant system to L-CTC computer and HADAX, and equipments are simplified and systems are modernized with the addition of the control function, as a upgraded LCP control system, to L-CTC computer on the basis of WINDOWS based O/S switched from DOS environment. An error on Microlok, which is aninterlocking apparatus, forwarded to L-CTC computer ensures to handle the false data during the operation of the system. This paper discusses a sure way to prevent the deterioration of (SMRT) L-CYC system and to bolster its stability with formation of the dual system. Additionally, WINDOW based O/S consisting of L-CTC computer leads to simplification and modernization of facilities and enhances maintenance functions offering centralization for branch offices and machine rooms as well.

• Journal of Environmental Science International
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• v.27 no.11
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• pp.947-956
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• 2018

Trains have been a major means of transport in Korea during these past decades. However, train facilities such as stations and repair shops are contaminated with organic and inorganic substances. There is a high probability of train facility contamination with polyaromatic hydrocarbons (PAHs). This study evaluated the PAH and heavy metal contamination of soil near railroads in the Kyungpook area. A total of 18 soil samples were collected from the railroads and analyzed for 16 PAHs and 6 heavy metal species. The contamination level of the top soil was found to be slightly higher than that of the subsoil for contamination with PAHs. The ratio of carcinogenic PAH concentration to the total PAH concentration was relatively high, with a maximum of 0.9. The toxicity equivalent (TEQ) of the PAHs were 500.6 ng/kg in the topsoil and 355.5 ng/kg in the subsoil. The ratio of low molecular PAHs (LPAHs) to high molecular PAHs (LPAHs) ranged from 6.7 to 29.5; this shows that contamination is primarily due to combustion of fuel rather than due to petroleum. The ratio of phenanthrene to anthracene and the ratio of fluoranthene to pyrene also show that contamination occurred due to combustion for transportation. The heavy metal contamination level was lower than the Korean standard, but higher than the background concentration; this indicates that the soil was affected by the operation of the railways.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.66-72
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• 2019

To improve ride quality and running stability of high speed train(HST), it is important that connection between coaches adopts the articulated bogies by using a gangway ring, unlike the conventional independent bogies assembled with car bodies. Although the gangway ring should be ensured absolute safety against passenger movement between coaches during train operation, there is still a lack of quantitative durability criteria of that. Therefore, in order to improve the passenger safety of HST, it is important to study the test requirements on durability evaluation for the ring. In this study, seven mixed loading cases were derived from the triaxial loading(vertical/lateral/longitudinal) modes. The safety factor of each component is at least 2.4 or more from the results of the finite element analysis. In addition, fatigue safety was evaluated through durability analysis from the viewpoint of strain-life design. Durability tests for the gangway ring carried out a total of 10 million cycles in 4 phases load conditions. After the durability test, the defect of each component was investigated using nondestructive testing techniques.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.3
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• pp.231-238
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• 2021

In addition to individual calls and group calls, the Trunked Radio System (TRS), which belongs to a group, can make calls simultaneously, and many users can use it within a limited time by adjusting the call time. Also, the LCX infrastructure network of the subway Most of the FM, firefighting radio, TRS of the National Police Agency and the terrestrial DMB service built in 2005 are commonly connected to the network for service and operation. In connection with the analysis, call reception sensitivity, handoff, interference with other signals, time delay, etc. were analyzed, and tests such as reception field strength for each output of the repeater and the success rate of the call terminal were conducted and the test results were analyzed. In addition, it will help TRS cell design and network construction by predicting equipment output capacity and service coverage based on test results.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.3
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• pp.147-155
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• 2022

The accumulated ice and snow during the operation of aircraft and railway vehicles can degrade aerodynamic performance or damage the major components of vehicles. Therefore, it is crucial to predict the temporal growth of ice for operational safety. Numerical simulation of ice is widely used owing to the fact that it is economically cheaper and free from similarity problems compared to experimental methods. However, numerical simulation of ice generally divides the analysis into multi-step and assumes the quasi-steady assumption that considers every time step as steady state. Although this method enables efficient analysis, it has a disadvantage in that it cannot track continuous ice evolution. The purpose of this study is to construct a surrogate model that can predict the temporal evolution of ice shape using reduced-order modeling. Reduced-order modeling technique was validated for various ice shape generated under 100 different icing conditions, and the effect of the number of training data and the icing conditions on the prediction error of model was analyzed.

• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.2
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• pp.121-139
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• 2023

Various tunnels such as road, subway, and railway are under construction and operation. Various types of linings are used for structural stability of tunnel structures, and concrete segment linings are mainly installed in TBM tunnel construction. In this paper, when a fire occurs in a tunnel, the impact on the concrete segment lining, which is the structure in the tunnel, and related standards, fire resistance evaluation and fire resistance method are investigated through literature review and related contents are presented. Through this, it is intended to provide an information for practitioners to secure the safety of concrete segment linings against tunnel fires.