• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.1-9
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• 2016

Train control systems have changed from wayside electricity-centric to onboard communications-centric. The latest train control system, the CBTC system, has high efficiency for interval control based on two-way radio communications between the onboard and wayside systems. However, since the wayside system is the center of control, the number of input trains to allow a wayside system is limited, and due to the cyclic-path control flows between onboard and wayside systems, headway improvement is limited. In this paper, we propose a train interval-control and train-centric distributed interlocking algorithm for an autonomous train-driving control system. Because an autonomous train-driving control system performs interval and branch control onboard, both tracks and switches are shared resources as well as semaphore elements. The proposed autonomous train-driving control performs train interval control via direct communication between trains or between trains and track-side apparatus, instead of relying on control commands from ground control systems. The proposed interlocking algorithm newly defines the semaphore scheme using a unique key for the shared resource, and a switch that is not accessed at the same time by the interlocking system within each train. The simulated results show the proposed autonomous train-driving control system improves interval control performance, and safe train control is possible with a simplified interlocking algorithm by comparing the proposed train-centric distributed interlocking algorithm and various types of interlock logic performed in existing interlocking systems.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.1
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• pp.149-156
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• 2012

This paper suggests the data transmission technology for applying to the actual railway line based on the technological trends and theories for the wireless Mesh techniques. This paper presents a technical basis that is applicable to the economic and efficient use of frequency and to the development of a Communication Based Train Control System by demonstrating its Applicability, Availability, Reliability and Safety for the train control system of the radio frequency of the bandwidth of 5.7 GHz at the experiments.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1269-1274
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• 2011

To cut down the maintenance expenses at branch lines, the foreign developed countries have developed the low-cost signalling on low-density lines. These examples are FFB(FunkFahrBetrieb) Radio based train operation by German railways(Deutsche Bahn AG), ERTMS REGIONAL by Europe and LOCOPROL system using a GPS. Also, Korea is developing Information and Communication Technology based low-cost signalling on low-density lines. The characteristics of this system are directly controled switch and crossing by driver. For the purpose of this paper, we reviewed the business process for switch and crossing control. Specially, we compared and analysed both methods whether the driver takes control over the operation procedures of switch or the control message is carried by the command of the controller. And by utilizing the instrument of UML, I planned the switch according to the control authority and the operation procedures needed for the control of crossing.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.12
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• pp.1796-1803
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• 2015

Unlike commercial LTE network, LTE-R railway network is arranged along a railroad track and the base stations of the network (RUs) are also installed on the waysides. For urban railway systems that are composed of underground tunnels, the leakage coaxial cables are widely used due to the radio propagation characteristics in tunnels. In theory, the tunnel sections are interpreted as the waveguide with blank spaces and for this reason, the tunnel sections are expected to be better than open ground sections in terms of the radio propagation characteristics. In this paper, we analyze the radio propagation characteristics based on this theory by replacing the leakage coaxial cables in the network with Yagi antennas. The test has been carried out in the 2.2km tunnel in the Daebul test track of KORAIL with 2.6GHz LTE-R Network. The LTE-R applicability in urban railways has been tested through the analysis on the radio propagation characteristics with the unmanned train operation system in Daebul tunnel.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.4
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• pp.563-570
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• 2023

The Safety Transmission Unit(STU) is a critical device used in railway systems to ensure safe and efficient operations by providing communication between trains and railway infrastructure. It is responsible for transmitting vital information and commands, allowing for the control and coordination of train movements. The STU plays a crucial role in maintaining the safety of passengers, crew, and the overall railway network. This paper presents the design and testing of a STU for the next-generation wireless-based train control system. An analysis of european and domestic standards was conducted to review requirements and ensure the design of a STU for the train control system meets international standards. Based on this analysis, hardware and software designs were developed to create an internationally recognized level of safety for the communication device. To verify the functionality of the STU, a simulator was developed, and it was confirmed that the designed features were successfully implemented.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.3
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• pp.533-539
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• 2017

ERTMS/ETCS Level 2 is currently planning, making contract, constructing and operating at several lines in European well-developed railway countries different from past ten years ago, and applying extensively for purpose of its intercompatibility and operational efficiency, and economic feasibility. On the other hand, ATP system correspond to ETCS Level 1, which was domestically introduced in early 2000, has introduced, operated, and planned or constructed in national railwaynetwork, but the lines, which its improvement period is come, are being occurred starting Gyeongbu Line. Therefore, we study the consideration and construction plan by stages if LTE-R Korean Radio-based Train Control System for conventional & high-speed railway under domestic development is extensively applied as the third National Railway Network Construction Plan was announced.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1054-1060
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• 2010

LRT(Light Rail Transit) is currently adopting a more upgraded signal system these days. This latest signal system is a train on-board signal system with moving block based on the realtime bi-directional wireless communications. The system applies RF-CBTC(Radio Frequency - Communication Based Train Control System) in order th execute fully automated manless operation. This paper reviews the performance requirements and safety of RF-CBTC that will be applied to the fully automated manless operation for LRT.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.7
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• pp.1303-1310
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• 2016

The track circuit carries out a train detection using a electrical closed loop, and incidentally it detects the rail rupture using the track circuit current flowing rail. However, in the case of the axle counter or the Radio based train control system, it requires a new way for detecting the rail rupture because of not using the track circuit. To solve this problem, it periodically checks non-steady state of rail by the track inspection car. but real-time detection of the rail rupture is impossible. Therefore, this paper analyzed feasibility to realize a real-time detection of rail rupture by using the return current.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2787-2794
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• 2011

A mesh node, a component of a mesh network, is connected with the network by dynamic routing using routing protocol and collects the information of adjacent or connected mesh nodes for its self-management and settings. Also, it relays packets between the mesh nodes and provides AP(Access Point) with its corresponding functions based on IEEE 802.11 a/b/g for clients' access to the network. In this paper, the study focused on the design and performance tests of Wireless Mesh Network(WMN) which is applied to the wireless communication network for the CBTC(Communications Based Train Control) system. The WMN was established on a K-AGT test-line (Kyeongsan city, Gyeongsangbuk-do), and to verify the applicability, its operation and performances are checked by measuring the data throughput, delay latency, quality measurements such as transmission loss, radio interference and path recovery and setup between the on-board and wayside.

• Journal of the Korean Society for Railway
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• v.16 no.4
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• pp.262-271
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• 2013

Wireless communication networks are recently taking an important role in railroad systems as railways now require high speed and high density operation with the aid of advanced information technology to improve maintenance efficiency and to handle passenger service growth. Train control systems are consequently changing from track circuitbased systems to communication-based systems. This paper analyses the role of wireless communication networks in recent railroad systems, reviews foreign cases, and then suggests a communication network constructing policy for increased transport capacity increase, securement of safety, and efficient train control.