• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.731-735
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• 2006

The Rolling Stock pursues more safe, speedy and accurate operation on the increment of the passenger and the short headway. Signalling system is providing an assurance on safety and reliability of the system, which is based on fail-safe concept. Therefore we are willing to study up on MMI device for new onboard ATP/ATO equipment which is used for driver to recognize train status and fault more quickly and to solve any problem more rapidly, which can maximize the stability and reliability of the system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 A
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• pp.384-386
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• 1998

In the emergency case such as a single line operation in a double line section because of a line broken or train's mal-operation, single line equipments that can operate without a line indication are needed. The main purpose of this study is to verify and analyze the availability of the single line operation that is able to operate without the indication of up or down line, and to offer a realizably alternative method to improve this situation. In order to carry out this study, we concentrated on getting related information. And to adopt the single line operation to existing line, the technology survey of other countries signalling system and the technical analysis of the interior signalling equipment were performed. As a result of this study, the required system and effect of the single line operation system were represented.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.396-405
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• 2009

열차제어 지상신호시스템에서 핵심적인 철도보안기능을 수행하는 연동장치는 철도산업의 안전성 확보 지침에 따라 높은 안전성과 신뢰성을 갖추어야만 한다. 따라서 연동장치는 높은 안전성과 신뢰성을 달성할 수 있도록 실시간 운영체제 및 그 구성 하드웨어의 랜덤 고장에 대처하기 위한 Fail-Safe형 다중 제어시스템으로 구성된다. 이러한 구성에서는 운영자 인터페이스를 포함한 다양한 장치와의 메시지 교환을 위한 인터페이스 가능을 구현하기 어려운 특성이 존재한다. 본 논문에서는 연동장치와 상위 인터페이스 설비간의 통신기능을 구현하기 위한 Dual Ethernet 네트워크 구성 및 DPST (Dual Packet Seamless Transfer) 통신 프로토콜을 제안한다. 제안된 시스템의 구성에서는 특정 네트워크 장비의 랜덤 고장이나 통신오류에 강인한 특성을 보이며 통신채널의 장애를 검출할 수 있는 기능이 추가되어 설비의 유지보수에 효과적인 정보로 활용될 수 있음을 실험적으로 검증한다. 제안된 네트워크 구성 및 운영 프로토콜을 현대제철 전용철도용 전자연동장치에 구현하고 그 성능과 특성을 유럽표준규격 EN50159의 지침을 토대로 타당성을 분석한다.

• 전기학회논문지
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• 제62권9호
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• pp.1324-1328
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• 2013

The reason of train location detection is generally the train interval control between the railway stations and the train path control in the railway station yard in order to avoid train collision. It is very important to know the train location for shortening the train headway, and improving the efficiency of railway maintenance as well as the safe operation of trains. Therefore, the accurate detection of train location is the prerequisite technology in railway signalling system. The track circuit and the wheel sensor of rolling stock have been used to detect the train location widely in urban railway as well as high speed train. The track circuit is continuously monitored by electrical equipment to detect the absence of the train and the tachometer and encoder is used for the wheel sensor to measure the train speed. But speed sensor failures are frequent due to the extremely harsh operating conditions encountered in rail vehicle. The CBTC(Communication based Train Control) system has been used in urban railway system recently. But the installation of CBTC system is very high and the modification of design is difficult. This paper deals with the feasibility of new train location detection method using magnetic sensors.

• 한국컴퓨터정보학회논문지
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• 제25권2호
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• pp.83-92
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• 2020

본 논문에서는 5G 시스템에서 저지연 통신들을 위한 효율적인 세션 관리 기법을 제안한다. 본 논문에서의 효율적인 세션 관리 기법은 저지연 통신들을 위한 세션 설정 실패 시 불필요한 재시도 제어 오버헤드를 방지, 단말의 배터리 소모를 막고 네트워크 리소스 낭비를 방지할 수 있도록 제안한다. 제안하는 기법은 만약 단말이 네트워크 실패 혹은 리소스 부족으로 인하여 5G 시스템과의 저전력 통신을 위한 Always-on PDU 세션 설정이 실패했을 때, 5G 네트워크로부터 실패 관련 특정 정보를 포함한 NAS 메시지에 의하여 단말의 Always-on PDU 세션 재설정을 제한한다. 실험 결과, 현재 3GPP 5G 시스템에서의 세션 관리 방안과 비교하여 제안하는 ESMS는 불필요한 제어 오버헤드를 최소화하고, 단말의 배터리 효율성을 향상시킬 수 있음을 확인하였다.

• 한국정보처리학회논문지
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• 제6권3호
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• pp.729-741
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• 1999

ATM networks are widely deployed as the network that is capable of supporting multimedia services efficiently now. To date, a large portion of ATM connections, particularly in the WAN environment, have been of a permanent virtual circuits-requiring management intervention for set-up and tear-down. However, switched virtual circuits are required to support a range of desired characteristics on demand, to a reachable end user. To establish, maintain and release on-demand call/connections, the user-network interface(UNI) and node-node interface(NNI) signalling capabilities are required. Two protocols have been specified for NNI signalling within a public network: the broadband integrated-services user part(B-ISUP) protocol specified by the ITU-T, and the private network-network interface(PNNI) protocol specified by the ATM Forum. PNNI offers different type of internetwork or internodal interface from the traditional B-ISUP approach favored to date public network operators. In spite of its name, PNNI may find its place in network service provide networks as well as in private networks. Thus many public network operators and ATM equipment manufacturers are still unable to choose the NNI interface architecture of their system. In this paper, we survey the characteristics of the B-ISUP and PNNI protocols, and investigate the applicability issue of these specifications to the ATM-based Information Infra-Network of Korea. Analyzing the characteristics of the two protocols and clarifying the NNi requirements of the ATM-based Information Infra-Network of Korea, we propose that the B-ISUP protocol is more suitable than PNNI.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.843-848
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• 2005

Currently the train traffic control system is built wholly by one package construction. It is under variable circumstance such as variation of signalling equipment and station expansion. This condition reduces system reliability and availability. And the term of system change is longer than 10 years, so it is hard to update to the latest technology and the new function. In order to do the system should be replaced to new one completely. The step by step construction of ADS(Autonomous Decentralized System) is one of the solution. So the simulation of it on the real station help to find system requirement and verify good of online expansion and online test.

• 한국철도학회논문집
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• 제9권5호
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• pp.601-605
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• 2006

Reliability of the Railway signaling system which is safety critical is determined by reliability of hardware and software. Reliability of hardware is easily predicted and demonstrated through lots of different studies and environmental tests, while that of software is estimated by the iterative test outcomes so estimates of reliability will depend on the inputs. Combinations of inputs to and outputs from the software may be mostly combinatoric and therefore all the combinations could not be tested. As a result, it has been more important to calculate reliability by means of a simpler method. This paper identifies the reliability prediction equation applicable to reliability prediction for railway signaling system software, and performs the simulation of onboard equipment of automatic train control for high speed train to review reliability prediction and validity.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1291-1296
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• 2004

CBTC(Communication Based Train Control) System has many superior train control performances than conventional track-circuit-based train control system with higher train operation efficiency, and less installation and maintenance cost. It is expected that CBTC will replace the conventional train control systems in near future. As CBTC has different mechanisms from conventional track-circuit-based train control systems in identifying train positions, and communicating information between train and ground facility, we have to pay a carful attention to making the interface between CBTC equipments and other signalling devices. This paper provides the construction of the interface between CBTC train-born equipment and other train control equipments including ATO, TCMS, brake controller, door controller.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(III)
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• pp.252-257
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• 2003

It is necessary to have a maintenance of track and its equipment for safety and s the railroad transportation. In the paper, we examine the safety problems, protecti and composition of protection system for safety within the track which RTRI develo system consists of a mobile business tool carried by each worker. a terminal of t platform temporarily installed in the maintenance car. a connector attached to signalling system and a central administrative device installed at the control cen used independently to detect positions of workers and maintenance cars. Each m correctly grasp the geometrical relations with other workers cars and other objects conditions based on the state information exchanged between the machines by the control protocol. the track occupancy monitor information broadcast by th administrative device and the line information. The protection system executes its f this basic structure.