• Journal of the Korean Society for Railway
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• v.11 no.4
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• pp.349-356
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• 2008

Put Safety-critical systems related to the railway communications are currently undergoing changes. Mechanical and electro-mechanical devices are being replaced by programmable electronics that are often controlled remotely via communication networks. Therefore designers and operators now not only have to contend with component failures and user errors, but also with the possibility that malicious entities are seeking to disrupt the services provided by theirs systems. Recognizing the safety-critical nature of the types of communications required in rail control operations, the communications infrastructure will be required to meet a number of safety requirements such as system faults, user errors and the robustness in the presence of malicious attackers who are willing to take determined action to interfere in the correct operation of a system. This paper discusses the safety strategies employed in the railway communications and proposes a security mechanism for Korean railway communication system. We present the developed communication safety evaluation tool based on the proposed security mechanism and also evaluate its protecting capability against the threats of masquerading, eavesdropping, and unauthorized message manipulation.

• Journal of Internet Computing and Services
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• v.8 no.3
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• pp.1-7
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• 2007

Since the DirectTV started its digital broadcasting services in 1994 for the first time in the U.S., digital broadcasting widened its services in many areas. In korea, TIT(Transport Information Technology) based IP-TV services have been provided in Saemaeul trains and some sections of subway trains. But the software systems for the service performed in alternated fashions and suffered from many problems such as suspension, memory leaking and overflow. These problems increased playback loss time and resulted in bad reliabilities. In this paper, a software TIT monitor is designed and implemented for the TIT system in physically poor environments. The designed system formalized monitoring time intervals for effective monitoring. Through the real experiments, playback time is improved in 14% comparing to existing system.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1707-1714
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• 2011

Since 2010 December, the Gyeongchun line can provide better service than the other modes in respect of cost & time efficiency by operating electric double track from Sangbong station to Chuncheon station. However customers living in the Northern part of capital area, which there are stations of line No.1, have inconvenience to transfering twice to access Gyeongchun line. To minimize inconvenience, this study has analyzed the demand variation of Geongchun line upon changing the terminal of some trains on Gyeongchun line which reduces the number of transfer. In this study, the demand variation has been estimated by the direct demand model considering only saving time between O/D. So some additional modifications are required, because the effect of fare and accession convenience has not been considered.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2007.10a
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• pp.19-36
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• 2007

When the trains runs at a high speed in the tunnel, passengers feel a pain in the ear that fast pressure fluctuation inside the tunnel being delivered with pressure fluctuation inside the passenger car. These phenomena are called "aural discomfort". Aural discomfort increase the passengers' uncomfort so that it is decreased a service level and serious case, it is able to damage the ear of the passenger. therefore aural discomfort must be considered the high-speed railroad tunnel cross-section design. To solve the problem of aural discomfort in a railway tunnel, some countries have standards on aural discomfort. It has been studied that different countries have different standards on aural discomfort. For that reason, the criteria of aural discomfort was reviewed through the standards of Kyungbu HSR line and different countries in this paper. And then Numerical Analysis of the Characteristics with tunnel cross-section change has been used for the selection of the optimum cross-section of Honam. The numerical analysis results were compared to field test results in order to verifying the reliability of the numerical analysis.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.2
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• pp.51-56
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• 2008

High quality power supplying of high voltage distribution lines electric railway system is the important function, high voltage distribution system is complicated witch is compose with distribution line, circuit break, protection facilities and so on. Among this components, role of substation is most important for elevation of reliability in electric power system. Therefore, the enhanced reliability considering the preventive inspection, repair work replacement is necessary. This paper proposes protection method in railway high voltage distribution lines. we model distribution system using PSCAD/EMTDC(Power System Computer Aided Design/Electro Magnetic Transients DC Analysis Program) and extract various fault data. In conclusion this methods can protection of ground fault.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.549-552
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• 2018

One of railway communication technology, LTE(Long Term Evolution) based LTE-R(LTE-Railway) is rapidily adopted to supply various control signal and to supply diverse communication service be needed for safety operation of train. In this paper, railway communication technology and service based on LTE-R is studied. And domestic an international standardization trends of related on railway communications are investigated. Results of this study can be used as basic data for research of railway communication based on LTE-R and development of railway communication systems.

• Satellite Communications and Space Industry
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• v.14 no.1 s.29
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• pp.102-109
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• 2007

본 논문은 고속열차와 같은 고속 이동체에서 위성무선연동 전송기술을 이용하여 지상무선망과 동일한 수준의 인터넷 서비스를 제공하기 위한 이동형 위성 인터넷 접속기술에 관한 것이다. 이러한 서비스 제공을 위해서는 터널이나 역사(Railway Station)와 같은 N-LOS 환경에 대한 대처기술이 필요하며, LOS 환경에서도 철로상에 설치되어 있는 Electronic Power Post나 Power Bridge 등으로 인한 주기적이고 짧은 시간동안의 신호열화 현상이나 고속 이동에 따른 도플러 현상에 대한 극복기술이 필요하다. 이러한 기술들이 집약된 본 시스템을 소개한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.864-867
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• 2016

In high speed railway system, LTE(Long Term Evolution) based LTE-R(LTE-Railray) mobile technology is used to supply various control signal required for safty operation of train. In this paper, railway communication technology be used in railway communication system based on LTE-R is investigated in focused on application services. Standardization trends for LTE-R technology are also considered. Results of this study can be used as basic data for research and development of LTE-R and railway mobile communication.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.6
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• pp.1025-1032
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• 2017

In this paper, the level of service (LOS) is defined for high-speed railway links and rolling stocks. Based on this LOS, how to manage high-speed railway facility is also suggested. The LOS is divided into 6 levels from A to F. The measurement of effectiveness (MOE) for railway links is derived from the relationship between a total delay time and a railway link utilization ratio. Another MOE, volume over capacity (V/C), is also proposed. On the other hand, the LOS for high-speed railway rolling stocks is based on the density of people in a rolling stock. Above all, LOS D is defined to the total number of seats. Then, LOS A is 50% of the LOS D, LOS B is 70% of the LOS D, LOS C is 90% of the LOS D and LOS D~F is defined as the maximum seats and standing people at the level of each. Finally, a method to manage high-speed railway links and rolling stocks is proposed in order to keep the level of service at the target by the government.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.9
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• pp.1172-1179
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• 2020

With the establishment of the railway integrated radio network (LTE-R) environment, radio-based train control transmission and reception and various forms of service are provided. The smooth delivery of these services requires improved performance in a highly reliable and available wireless environment. This paper measured the LTE-R radio communication environment to improve radio communication performance of railway integrated wireless network reliability and availability, analyzed the results, and established the wireless environment model. Based on the built-up model, we also proposed an improved radio-access algorithm to control trains for improved reliability, suggesting a way to improve stability for handover that occur during open-air operation, and proposed an algorithm for frequency auto-heating to improve availability. For simulation, data were collected from the Korea Rail Network Authority (Daejeon), Manjong-Gangneung KTX route, which can measure the actual data of LTE-R wireless environment, and the results of the simulation show performance improvement through algorithm.