• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2206-2207
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• 2011

컴퓨터 통신기술 발달에 따라 철도의 열차제어에 대한 기술도 기존의 궤도회로기반에서 무선통신기반으로 변화되고 있다. 국내에서도 도시철도용 무선통신기반 열차제어시스템의 개발이 진행됨에 따른 개발품의 성능평가에 대한 관심이 높아지고 있다. 따라서 본 논문에서는 새롭게 개발되는 무선통신기반 열차제어시스템의 성능평가를 위해 성능시험 항목의 선정과 현장에서의 시험을 위한 시험선로 지상 및 차상인프라 구축에 대한 기본적인 검토를 기반으로 시험 및 성능평가 시행의 종합기본계획을 수립하는 검토를 수행하였다.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1236-1238
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• 2001

The electrified railway has various power supply schemes. Although the identical trains are operated in same condition and the impedance of track are equal, the genealogy impedance of track is changed according to composition method of feeding scheme. So, the collection voltage of train and supplying power from railway substation are greatly unlike. For simulation of collection voltage and power supply according to feeding scheme, using 6-port network analysis proposed previously simulate collection voltage and supply power according to feeding scheme(Parallel Post feeding system, normal feeding system and tie feeding system) and compare and investigate each characteristics.

• Journal of information and communication convergence engineering
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• v.18 no.1
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• pp.28-32
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• 2020

Railway transportation is the main land-based transportation in most countries. Accordingly, railway-transportation safety has always been a key issue for many researchers. Railway pedestrian accidents are the main reasons of railway-transportation casualties. In this study, we conduct experiments to determine which of the latest convolutional neural network models and algorithms are appropriate to build pedestrian railroad accident prevention systems. When a drone cruises over a pre-specified path and altitude, the real-time status around the rail is recorded, following which the image information is transmitted back to the server in time. Subsequently, the images are analyzed to determine whether pedestrians are present around the railroads, and a speed-deceleration order is immediately sent to the train driver, resulting in a reduction of the instances of pedestrian railroad accidents. This is the first part of an envisioned drone-based intelligent security system. This system can effectively address the problem of insufficient manual police force.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1029-1036
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• 2006

South and North Koreas are putting forth efforts to overcome the distrust and animosity of the past 50 years to open an era of harmony and cooperation where the two halves can work together for mutual benefits. As part of those efforts, both parties are working now to reconnect the railways between the North and the South that remained broken for the past 60 years. In addition, the restoration of Trans-Korean railway paves the way for the "Silk Road Railway" which links European continent to Asian regions and Pacific Rim. The restoration project acts as a conduit for cooperation within in the Northeast Asian continent, hence, an important tool for facilitating peace and prosperity within the Northeast Asian region. Notably, the Railway project is regarded as the cardinal future-oriented peace building project for cultivating constructive, cooperative relations (Trans-Korean Railway and Trans-Asian Railway works) by stimulating human resources and commodity flows through railroad transportations. Northeast Asian region takes on a similar instance to the unification of European continent through its astounding development in railroad transportation, i.e., the international re-construction of Railroad lines will act as a catalyst to link Eurasian areas into one regional community for cooperation and peace. At present, the government is creating a momentum to bind trans-Eurasian railroad works and an initiative for "Northeast Asia Railroad networks and consultative organization". The South Korean administration paves the way to develop railroad network within South-North Korean, Russia and Eurasian region. It also fosters railroad cooperation with China for people and goods transports. To achieve such objectives, the project requires wide publicity and cross-border cooperation from concerned countries. The blueprint would have to be drafted up for Northeast Asian railroad train demonstration runs, Northeast Asian transportation agreements, with a bid to promote constitute Northeast Asian Railroad Consultation body. Moreover, the government would also have to prepare both, a draft of the linkage and the mandated standardized proposal.

• Journal of the Korean Society of Systems Engineering
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• v.2 no.2
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• pp.45-50
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• 2006

Tilting technology is to tilt the train on the curve in order to minimize centrifugal force to passengers and to improve the speed within the limits of passenger's comfort and safety. According to reports from other countries, there is 15~30% speed improvement compared to the conventional trains. Recently, the advent of World-Wide-Web(WWW) and the explosive popularity of the Internet gave birth to collaborative applications which were enabled by computers and networks as their primary media. The progress of 3D computer graphics enabled collaborative applications with 3D virtual environments or distributed virtual environments. In this paper, we explain our implementation of the Share collaboration engine which is for collaboration applications based on a distributed virtual environment. The Share collaboration engine proposes a new Share network architecture for management of participants, and it provides some synchronization methods for 3D objects in virtual collaboration. TTX_PDM is an experimental application that tries to prevent wastes of human, material and time resources in networked virtual collaboration.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.51 no.6
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• pp.255-261
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• 2002

Recently, traction motors in trains are supplied with single phase a.c. power. After this power is converted to d.c. power, it is inverted to three phase power to operate traction motors. As going through the process of the conversion, harmonic current is generated in train. The method of conventional analysis on harmonics, studied by RTRI, is modeled with equivalent circuit of ac AT-fed electric railroad system using by the distributed constant circuit. However, this circuit as two-port network model has some difference in comparison with real system. The reason why the conventional method is different from the real system is that the conventional method dose not include three conductor groups, that is catenary, rail, and feeder, and admittance between the conductors for line capacitance. Therefore, this method has a little error. This paper proposes new method to more effectively estimate Harmonic current. In this method, numerous components in electric railway are categorized and each component is defined as a four- port network model. The equivalent circuit for the entire power supply system is also described into a four-port network model with connections of these components. In order to evaluate the efficiency and the accuracy of a proposed method, it is compared with values measured in Kyung-Bu high speed line and ones calculated by the conventional method.

• Journal of the Korean Society for Railway
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• v.16 no.6
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• pp.534-539
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• 2013

The research about the Korean integrated wireless network for railways is in progress. The network integrates and complements the various railway functions. In addition, the network is trying to change from wire communication to radio communication. The activities for the railway frequency acquisition are also in progress for the implementation of the network. This paper analyzes the problems for the Korean railway communication networks. The problems revolve around the dispersed network structure, the limited functions, the different communication methods, the technology limitation for the communication methods, and the usage of the non-licensed band. Subsequently, we explain the current state and trend for the foreign communication of the railways. This paper suggests improvement plans for the problems and also explains the expected efficiency for the improvement plans.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.5
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• pp.883-887
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• 2016

The power supply system in Korean electrified railway has adopted AT feeding. If a fault occurs in some substation for any reason, the vicinity substation must feed electric power on the outage substation through catenary. So, the feeding distance grows twice of the normal state at extended feeding condition. If substation's feeding distance is longer than normal condition, the catenary impedance and train to supply electric power from the substation. Therefore, the severe voltage drop can occur and power supply shall be not allowed. This paper presents the model of compensator against voltage drop using multi-port network algorithm. Whole traction power supply system can be analyzed with this model. Computer simulation including this model is performed based on real train schedule and increased schedule in case studies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6604-6610
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• 2015

In this paper, an efficient Wireless Access in Vehicular Environment (WAVE) packet transmission scheme for railroad communication is proposed. WAVE communication is a wireless local area network (WLAN) based communication and it is developed to be suitable for vehicular communication. There has been a lot of study on WAVE's applicability to Intelligent Transport System (ITS). As one of main transportation methods, by using WAVE, quality of railroad communication including WLAN based Communication Based Train Control (CBTC) can be enhanced and variety of railroad communication systems can be integrated into WAVE. However, there are technical challenges to adopt WAVE in railroad communications. For the simplest single-PHY WAVE, time division alternation of 50ms between Control Channel (CCH) and Service Channel (SCH) is required. Since there are delay sensitive railroad traffic types, alternation operation of CCH and SCH may cause performance degradation. In this paper, after identifying a couple of problems based on detailed analysis, a novel packet transmission scheme under railroad environment is proposed. In order to verify if the proposed scheme meets the requirement of railroad communication, WAVE transmission is mathematically modeled.

• Journal of the Korean Society for Railway
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• v.20 no.1
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• pp.20-30
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• 2017

Due to the evolution of wireless communications technology, Long Term Evolution (LTE), which is a $4^{th}$ generation mobile communications system, has been adopted as a railway communications system. This LTE Railway (LTE-R) system is composed of various elemental functions, which are largely categorized into public safety and wireless communications for train control. Research on the public safety functions of railway communications have their roots in TRS based national public safety communication systems, and research on wireless communications functions for train control have their roots GSM-R, which is utilized by the ETCS in Europe. Based on these circumstances, this paper first analyzes the requirements for developing public safety technology in LTE-R, and compares those requirements with the functions of public safety LTE (PS-LTE), which is being deployed for the first time in the world by the South Korean government. Based on an analysis of the common and specific functions of LTE-R and PS-LTE, we conclude that there is little problem in integrating LTE-R and PS-LTE from the perspective of functionality. Second, this paper provides a comparison of the LTE-R requirements for the Quality of Service (QoS) with those of GSM-R utilized by the ETCS. This offers a guideline to allow LTE-R to be applied to a 500km/h train control system.