• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.448-454
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• 2010

Currently a KTX train of 20-car formation is 388m long and carries 931 passengers including one captain and three crews which is quite a few to cover the lengthy service area and many customers. On the other hand, if a passenger wants to talk to an attendant, he has to wait for an attendant passing by his/her seat or walk to an intercom which is placed at every other car. Any of these choices is inconvenient. So, in this paper, we presented a system design for developing an audio/visual communication system for a passenger and an attendant. The system was analyzed and designed according to the Object-Oriented methodology with UML (Unified Modeling Language). Based on a problem statement, a Use-case Diagram, Sequence Diagrams, Class Diagram, State Charts, collaboration Diagram were generated. The design will be used in system implementation to a HEMU-400X test train and to be tested.

• 한국측량학회지
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• 제13권2호
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• pp.209-218
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• 1995

철도속도향상 계획은 미래에 있어 풍요로운 사회를 실현시키는데 중요한 역할을 담당하게 될 것이다. 열차 운행속도에 매우 큰 영향을 주는 선형 요소는 곡선구간으로서 이 구간에서는 열차의 주행성과 승객의 승차기분을 저해하는 요인을 줄이기 위해 완화곡선구간을 포함한 곡선부에 캔트 및 슬랙을 설치하게 되는데 이러한 값들은 열차의 종류가 다르기 때문에 균형적인 값을 사용하지 못하고 어느 정도 부족한 상태로서 유지되고 있다. 본 연구에서는 곡선반경별로 설정캔트량을 조사하여 부족캔트량에 대한 횡가속도를 산출하여 곡선부에서의 주행성을 검토하여 효과적인 곡선관리 방법을 제시하였으며 선형개량요소를 적용하여 속도향상 효과를 얻었다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.2114-2119
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• 2008

When a train enters into a tunnel, a compression wave is generated by a front nose and a expansion wave is generated by a rear nose each other. Because the compression wave and expansion wave have interactions with the train in a tunnel repeatedly, the internal pressure of the train is dramatically varied. And this pressure variation gives passengers discomfort like ear-ache. In this paper, we had measured the internal pressure variation of TTX developed and being on Test-Running in Honam line and made an analysis of pressure variation rate. As a result, the internal pressure variation was different as to the length of tunnel. Though the entering velocity of TTX is similar on test tunnels, on the short tunnel, the pressure drop was lower then that of the long tunnel. And it was expected that the rates of internal pressure variation would be exceeded the limits on 160km/h entering velocity.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1936-1942
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• 2009

Shinbundang-line is new Metropolitan Railway which was invested by private capital and is under construction for opening in 2010. Now Shinbundang-line pursues various innovation, for example, an express train which uses long distance of each station, and an unmanned operation. And it may be independent of existing metropolitan railway system from a viewpoint of line and fare system. So according to the present plan, Shinbundang-line will be not able to get sufficient demand because of weak connection with existing lines and monotonous function of the line. And it may be difficult to deliver various innovation which Shinbundang-line prepares to passengers. Hereupon, in this paper, I propose 3 methods for increasing competitive power of Shinbundang-line railway. First, making Shinbundang-line a trunk railway line of southern metropolitan area was proposed in relation to northern and southern extension of it. In addition connection with bus and light rail was discussed. Second, multipurpose usage of Shinbundang-line was proposed as express train and conventional passenger train in that line in addition to simple metropolitan railway. Finally, an effective operation method which Shinbundang-line must have was proposed from unmanned driving and fare system side. These methods can improve Shinbundang-line and then it will solve traffic congestion of southern metropolitan area effectively.

• 시스템엔지니어링학술지
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• 제2권2호
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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.

• ETRI Journal
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• 제38권6호
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• pp.1052-1063
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• 2016

We propose a millimeter wave (MMW)-based mobile hotspot network (MHN) system for application in high-speed railways that is capable of supporting a peak backhaul link throughput of 1 Gbps per train at 400 km/h. The MHN system can be implemented in subways and high-speed trains to support passengers with smart devices and provide access to the Internet. The proposed system can overcome the inherent high path loss in MMW through system designs and high antenna gains. We present a simulation of the system performance that shows that a fixed beamforming strategy can provide high signal-to-interference-plus-noise-ratio similar to those of an adaptive beamforming strategy, with the exception of 15% of the train path in which the network can use link adaptation with low-order modulation formats or trigger a handover to maintain the connection. We also demonstrate the feasibility of the MHN system using a test bed deployed in Seoul subway line 8. The backhaul link throughput varies instantaneously between 200 Mbps and 500 Mbps depending on the SNR variations while the train is running. During the field trial, the smartphones used could make connections through offloading.

• 대한기계학회논문집B
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• 제32권9호
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• pp.645-651
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• 2008

For a high speed train driving at 300 km/h, aero-acoustic noise is a dominant component among various noise sources. The aeroacoustic noise is mainly due to inter-coach spacings because discontinuities in the train surface significantly disturb turbulent flows. This often leads to the uncomfortableness of passengers. Interestingly, the aero-acoustic noise reduces with decreasing the mud-flap spacing of the inter-couch spacing. We perform numerical simulations to investigate flow characteristics around the inter-coach spacing. We model the inter-coach spacing as a simple 2-D cavity with flaps, and calculate the velocity and pressure field using two equation turbulence models, varying the flap spacing. The results show that a wider flap spacing develops a higher inflection point in mean velocity profiles over the cavity. It is likely that large eddies generated near the inflection point persist longer in the downstream since they are less affected by the wall. This probably induces the more aero-acoustic noises. The wider spacing also results in the larger pressure difference between the inside and outside of the cavity. This is also responsible for the increased noise since the large difference would cause a strong flow oscillations in and out of the cavity.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집 특별세미나,특별/일반세션
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• pp.429-433
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• 2009

Since the "Low Carbon, Green Growth" as a social requirements is attracted public attention, the policies and investments of the railway which have been less estimated than road is re-considered. Since the starting the commercial service (2004. April), the KTX have been operated successfully while transport passengers over 100million for years. And also the project for development of KHST (Korea High Speed Train ; G7) had been accomplished with a good result, the first trainset of KTX-II which base on G7 project was manufactured and testing now. On the other hand, the world's technology of the high speed train is more faster, and changing to a distributed traction system. To catch up the world's leading technology, the HEMU(High-speed Electric Multiple Unit) project will secure new technology and aims to promote the technology of domestic high-speed train. The authors indicates the result of detail review such as a curve, slope of the track and electrical dead section of the catenary to test at 400kph and also the performance simulation of the developed rolling stock in this paper. As the result, the authors devise the test scenario to perform a maximum speed test (stability at max. speed, acceleration & deceleration etc) with the restricted conditions such as track length, track available time etc by considering above result.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1270-1278
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• 2008

A great deal of development has been made in the field of railroad control in Korea. Like the recent High speed railroad (KTX) and the intercity light rail train (LRT) are being vigorously promoted. Therefore, in concert with the new railroad development projects, improved train control technics are being applied. Along with the focus on these newly developed advanced technologies the need for a reliable safety system for the safety of the passengers and railroad control personnel alike is being intensified. New safety facilities are continuously being developed in order to safely introduce and develop these new technologies. There is an urgent need for research and development of safety facilities for the implementation of the presently developed facilities as well as for the presently being used. Therefore, this research will study the safe operation of Korean railroad and the implementation situation of the class, functionality, ensured safety range etc. of the safety facilities for users and operators. In studying the material of the kinds of implemented safety facilities and technologies being used abroad we have researched into the most suitable direction of development of safety facilities for the Korean railroad environment.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1264-1269
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• 2008

We designed a track circuit of Tag in-tag out type that can be used for light rails and monorails. This method is called RFID-Tag and it literally uses RFID-Tag and replaces a fixed track circuit and implements a moving block. The distance between RFID-Tags is set to the length of a train and thus a train is always in contact with one of the tags. A train runs in RFID-Tag in -RFID-Tag out type at all times and the distance between trains can be precisely controlled through the application of a moving block combined with the basic principle of a fixed block, which enables the continuous speed control and enhances the satisfaction of passengers. When constructing a track circuit using RFID-Tag the Tag in-tag out brings us the cost reduction and is more economical than the existing fixed track circuit in that sense and easy for installation and maintenance. The wireless communication between onboard and wayside makes the continuous control possible and can improve the control capacity of ATP/ATO by the implementation of a moving block on top of a fixed one.