• The Journal of the Korea institute of electronic communication sciences
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• 제15권3호
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• pp.473-478
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• 2020

The communication between train and it's moving environments is considered as a necessity factor to support accuracy and safety for operation of train. Communication structure and performance between sensor and train used to measure and monitor between train and it's moving environments is required in operation of the train. In this paper, railway sensor network based on LTE-R is described and analyzed for moving train to support effective measure operation and environment data from various sensor devices located through railway and then transfer the data to data control center. Finally, implementation requirement for railway sensor network is suggested.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• 제15권4호
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• pp.129-142
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• 2016

This study performs an evaluation, using the economic feasibility analysis method, of the LTE based railway wireless networks (LTE-R) service that is planned to be used for the future railway networks in Korea. Its objectives are using the evaluation results and working to reflect the factors that lead to a maximization of benefits in designing an integrated railway wireless network. This study analyzes the impact of implementing an LTE-R on the railway networks, in contrast to the existing wireless network methods, e.g. VHR and TRS to new rail lines on an economic view. This results found that the benefit cost ratio is greater than 1.0 with a 10% contribution to benefits of the wireless network service in the case study on the Wonju-Gangneung rail line that will start operations in 2018; as a result, an ICT design is desired. For the introduction of an LTE-R service for the Wonju-Gangneung rail line, design specifications need to increase to benefits for each service, which will verify actual contributions and therefore result in an overall economic effect.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제16권5호
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• pp.3071-3080
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• 2015

The increased demand on the transport of both passengers and goods through rail systems implies higher traffic intensity and congestion on the railways, resulting in greater likelihood of accidents and also degraded passenger services. To cope with the issues, development of an integrated communication network for rails has attracted great deal of attention lately. GSM-R is such an example developed in Europe, which seems to have restrictions in providing various communication services due to network speed limit. For the reason, an LTE-based approach is under study in Korea. After the network development, operation management of the network is necessary. Design of operation management systems has been studied little and thus is the objective of this paper. To do so, a conceptual design has been carried out based on model-based approach. Specifically, a context model has first been created using the use case diagram. Then, SysML models of operational scenarios were developed for the management system. The SysML models have alternatively been expressed as EFFBD models to simulate and verify them. Consequently, the result of the conceptual system design for the operation management of the integrated wireless network is expected to be used as a basis for the detailed design later.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• 제3권2호
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• pp.9-17
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• 2004

In this paper, we examine the MIMO(Multiple Input Multiple Output) system in the point of mobile communication that is used for railway environment. First, under the radio environment, wireless channel characteristics are analyzed between moving train and base station, both assuming track side base stations and non-track side base stations. Next, the paper introduces the MIMO system which can be used to solve the problem of performance degradation in railway environment, and analyzes its performance in terms of channel capacity and diversity. We especially compares open-loop scheme with closed loop scheme at the diversity and analyses their performance according to antenna correlation. Finally, the we presents experimental result from the ESCORT project that was studied in railway environment with the MIMO system.

• The Journal of the Korea institute of electronic communication sciences
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• 제9권7호
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• pp.819-825
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• 2014

The diurnal range of temperature in korea is increasing. We know that the environment has deteriorated through report about railway damage and economic loss caused by climate. In these conditions, Monitoring device for railway must operate to support the operations and maintenance. Therefore, In this paper, COM-based monitoring device implemented using Industrial-Extended electronic components and made, We tested compliance about temperature environment of actual railway. We verified through testing about cold and dry heat of monitoring device. Used components in this product will be able to utilize the development of the railway industry of electronics.

• TTA Journal
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• 통권169호
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• pp.102-107
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• 2017

• The Transactions of the Korean Institute of Electrical Engineers
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• 제37권12호
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• pp.903-913
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• 1988

Induced voltage causing disturbances on the communication lines of electric train is dealt with when the AT power supply system is employed. Induction interference is of three types, namely, normal state induced voltage, unusual induced voltage in case of power faults, and noise-induced voltage. Calculation of induced voltages occurring in the AT system is more complicated and extensive than in the BT system. In this paper we obtain an algorithm to calculate the induced voltages on the communication lines in the AT system and an algorithm for the induced current in case of the accident that the line falls to the ground. These algorithms are developed to a package of computer programs and their validity was checked on a simulated system. We supply the measures to protect the communication lines suitable for the AT system and we can also evaluate the protection capabilities. Because of the ability to evaluate the protection measures, this package is expected to be very useful when electric train system is constructed on communication lines near the railroad.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제33권7B호
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• pp.601-607
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• 2008

The induced voltages by AT power feeding system of electrified traction line to telecommunication line are calculated with the method of multi-conductor line solution in the CCITT Directives. There is a screening effect by railway line itself among various shielding factors against induction. It is the argue point whether the multi-conductor line solution contains the railway line effect since the calculation method does not show any expression about shielding factors. So this paper illuminates the mysterious question by reviewing the shielding factor principle on traction system, scrutinizing the Japanese bible about induction, analyzing the multi-conductor line solution itself, and comparing the result calculation considering the effect of railway screen. This paper concludes that multi-conductor line solution contains the screening effect of railway lines.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제11권10호
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• pp.3756-3760
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• 2010

In this paper we propose network design for power line communication of electric railway using messenger wire. we carried out feasibility study on the power line communication(PLC) using Contact wire and messenger wire which are required at electric railway. First of all, full-duplex data communication was implemented using coupler which is suspended on messenger wire at non-voltage state. We verified data transfer rate was found to be good, and then proposed a design example of PLC network as the main components for PLC. we will study continuously make an effort to verify on the network design of PLC for further study.

• The Journal of the Korea institute of electronic communication sciences
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• 제11권1호
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• pp.17-22
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• 2016

In relay networks, relay nodes amplify or demodulate/remodulate the received signal from the transmitter, and transmit that signal to the receiver. The received signals from several relays are combined and used for demodulation at the receiver, which enhances the performance of the overall system. Partially differential modulation scheme which uses coherent modulation at the relay and non-coherent modulation scheme at the receiver is adopted for modulation scheme. We analyze the performance of systems depending on various energy allocations of source and relays given the total energy in relay networks.