• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1694-1700
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• 2007

In the electrified section, both of return current and signal current are flowing in the same rail in common. But signal current shall be allowed to flow in the specific track circuit and not in the other circuit while the traction return current shall come back to power sub-station. This paper presents measuring system that use both sensor and antenna. The aim of the system is to achieve the difference in current between the two rails and the presence of trimming capacitors. In order to improve the transmission level, trimming capacitors are connected between the two rails at constant spacing. To maintain the balance of traction return current, rails of both sides may be jointed by the so-called SVPMM. The traction return current is sometimes unbalanced owing to the ill-contact of SVPMM. In this paper, we propose a diagnosis method based on a short-circuited current(Icc), trimming capacitors and traction return current measured by Korail inspection vehicles. Whether Icc is good or bad depends not only on the presence of trimming capacitors but also on the unbalance of the traction return current.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.124-132
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• 2010

To predict and analyze the rolling stock's fire growth is considered not only important factor in estimating hazard analysis of rolling stock, but also a primary factor in aspect of a rail load facility. Because it's could be regarded as a ignition source in risk assesment for the facility i.e. tunnel and station. However, currently, standardized method to predict and analyze the fire growth has not been completed yet. it is due to the fact that fire growth is not only depended on thermal property of interior materials, but also is affected dominantly by various factors such as ignition source (characterized by location, duration, and intensity), train running condition and in/exterior ventilation condition. Especially, ventilation condition is one of the most effective factor to affect fire growth in compartment space as noticed by under-ventilation fire condition. In this study, the effect of each ventilation condition on fire growth and load were examined through the numerical method through FDS (Fire Dynamics Simulator).

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.324-329
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• 2010

The surroundings around subway are becoming more lively for project of CBD (an redevelopment project), however vibrations which are made through passing train cold spread buildings around. The structure-borne noise could be generated at the same time that makes people including developers and th citizens have negative viewpoint on railway. Especially, Seoul Metro 1-4 lines ar built alongside the road nearby houses and business district. That could make plenty of public resentments because of the structure-borne noise. Seoul Metro should make active alternative plans for their future urban environment projects which will be conducted. The case was Railway Facility which were conducted to minimize structure-borne noise from sharp curved track section (4 line, Sinyongsan~Ichon, R 250m). The section is adjacent to house district as near as 6.6m related with pusing international city project, the 4th urban environment project around international building, near Yongsan station. The interval of sleepers would be downsized in half with breaking existing case, and pad stiffness is reduced 4 ton from 10 ton. That makes structure-borne noise minimized because of vibrations are lowered about 19.1-23.0db. The structure above has remained for a year and a half from October, 2008, and had not any trouble to perform excellence with 80million ton rail accumulated tonnage.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.273-281
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• 2010

300km/h의 고속으로 운행중인 선로구간에 중간역 설치에 따라 분기기 부설시 기존선로의 레일응력 해소방안이 필요하며 또한 속도제한을 높게 하고 기간을 단축시킬 수 있는 방안을 통해 열차 이용객의 불편을 최소화하여야 한다. 경부고속철도 중간역사 오송, 김천구미역 신설에 따른 분기기 설치는 짧은 야간 차단작업시간(1일 6시간)에 여러 부분으로 나누어 시행하여야 하고 곧바로 고속열차를 운행시켜야 하는 매우 어려운 조건으로서 국내에서는 처음이고 세계적으로도 매우 드문 사례이다. 본 논문에서는 작업조건, 장비, 안전조치 등에 관한 사항을 제시하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1223-1228
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• 2007

Since KHSL 2nd phase was adapted as a main track design, the interests of concrete slab track system have been gradually increased in the division of rail track engineering and many engineering companies have been trying to adapt a concrete slab track system at this moment. Advantages of this system proved in advanced country, japan and Germany etc. are excellent maintenance, track stability and increasing of buckling resistance This developed turnout is same with the KHSR 1st phase's design and applications rules, components and signaling system since it observes KTX specification. Comparing it with the former turnout, High-elasticity pad, lubrication-free roller slide plate and Rheda2000 PC sleeper are only different. The purpose of this study is the development of high speed turnout on concrete slab track and its application on site. Now these studies are going to show the verification and confidence about the interface between ballast-track and concrete slab track by finding and solving the possible problems when it is installed on site and to make these turnouts applied perfectly and completely on concrete slab track. Its first trial construction in korea had been successfully completed at Sangju-station on July 20th ,2007 thanks to KORAIL and KR. Hereunder Sampyo E&C trys to introduce all of turnout technologies on concrete slab track system with Rheda 2000 sleeper

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1647-1652
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• 2008

Track geometry consists of tangent and curved lines, which caused undesirable changes in initial track geometry by traffic loads. The bigger the changes are, the worse the riding comfort and running stability of train. This is so-called track irregularity and is the most important quality parameters of ballasted track. To be able to objectively assess track irregularity, track geometry should be able to be measured. Practically, railway companies use moving chord method, this method determine versine values via a chord. The versine is the vertical distance to curve measured in the middle of the chord. This type of method measures only versine of track irregularity curve by transfer function from specific property of measuring tool. In this report, review the characteristics of two types of measuring tools by comparing the measurements. The one is GRP-1000 system, optical surveying system with Total station and lazar prism trolly. This calculates track geometry by surveying absolute coordinates of two points each on both rail heads. The other is Trackmaster, measures versine with 2m of chord length.

• 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.

• 한국재난정보학회 논문집
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• 제9권1호
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• pp.113-122
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• 2013

우리나라는 철도이용객 증가에 따라 여러 다양한 철도안전 관련 제도 등을 마련하고 있으며, 이러한 차원에서 철도 보안검색시스템의 도입을 검토 중에 있다. 본 연구는 철도 보안검색시스템 도입에 앞서 이에 대한 충분한 대비를 위하여 외국의 철도보안검색제도 시행현황을 살펴보고, 국내 도입가능한 철도보안 검색방법 등을 제시하였다. 또한, 철도이용자들을 대상으로 하여 철도 보안검색 제도 시행과 관련한 설문조사결과를 바탕으로 철도 보안검색 제도에 대한 견해, 제도 시행 시 문제점, 개선방안 등을 파악하였다. 결론적으로 고속철도역에 대한 시범적 실시를 통해 점진적 시스템 도입이 필요하다고 제안하였다.

• International Journal of Computer Science & Network Security
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• 제23권5호
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• pp.121-127
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• 2023

A 500 km/h linear motor high speed terrestrial transportation service is planned to launch 2027 in Japan. In order to support 5G service in the train, the Sub-carrier spacing frequency of 30 kHz is planned to be used instead of common 15 kHz sub-carrier spacing to mitigate Doppler effect in such high-speed transportation. In addition, to increase the cell size of 5G mobile system, plural Base Station antenna will transmit the identical Down Link (DL) signal to form the expanded cell size along the train rail. In this situation, forward and backward antenna signals will be Doppler shifted by reverse direction respectively and the receiver in the train might suffer to estimate accurate Channel Transfer Function (CTF) for its demodulation. In this paper, Delay and Doppler Profiler (DDP) based Channel Estimator is proposed and it is successfully implemented in signal processing simulation system. Then the simulated performances are compared with the conventional Time domain linear interpolated estimator. According to the simulation results, QPSK modulation can be used even under severe channel condition such as 500 km/h, 2 path reverse Doppler Shift condition, although QPSK modulation can be used less than 200 km/h with conventional Channel estimator.

• 한국산학기술학회논문지
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• 제18권3호
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• pp.562-568
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• 2017

기존 선하역사의 소음 및 진동 문제를 해결하기 위해 제안된 사전 제작형 플로팅 슬래브 궤도는 길이 5m 정도의 슬래브 패널을 공장에서 제작하고 방진장치를 설치하여 일체화한 궤도이다. 이를 통해 별도의 열차 운행 중단 없이 급속 시공이 가능하여 신설역사 뿐 아니라 기존 선하 역사에 적용이 가능한 장점이 있다. 그러나 패널 길이가 5m로 짧아 실제 시공 구간 길이에 따라 다수의 패널이 설치되어야 함에 따라 궤도의 불연속 구간이 많이 발생한다. 또한 플로팅 슬래브 궤도의 작동 원리 상 일반 궤도에 비해 차량 운행으로 인한 과도한 변위가 발생할 여지가 있고 기존 궤도와의 접속부에서의 지지강성 차이로 인해 동적 불안정성이 발생할 우려가 있다. 본 연구에서는 사전 제작형 플로팅 슬래브 궤도에 대해 차량-궤도 상호작용 해석을 수행하여 윤중변동율, 차체가속도, 레일응력 및 상압력의 검토를 통해 동적 안정성을 확인하였다. 검토 결과 플로팅 궤도 구간 내에서의 동적 안정성은 확보하는 것으로 나타났지만 기존 궤도와의 접속부에서는 일부 기준을 초과하는 것으로 나타나 이를 해소하기 위한 방진장치 배치 방안을 제시하였다.