• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.346-353
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• 2005

Track substructure(ballast, subgrade) should have sufficient strength and adequate stiffness to fully support track superstructure(rail, fastener, sleeper). Vertical support stiffness of track comes from the sufficient thickness, adequate strength and stiffness of material of substructure layers. Since the vertical support stiffness of track substructure is closely related with the track geometry, the evaluation of the stiffness is very important to understand the track states. This paper introduces the system, which are composed of Ground Penetrating Radar(GPR), Portable Ballast Sampler(PBS), and Light Falling Weight Deflectometer(LFWD), to evaluate substructure condition and summarizes the field test results performed with the reliable system.

• 한국자동차공학회논문집
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• 제11권2호
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• pp.56-62
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• 2003

Spray characteristics of conventional diesel fuel and bio-diesel fuel(methyl-ester of soybean oil) were compared, in terms of spray tip penetration and spray angle, by using a commercial high pressure common rail injection system for light-duty DI Diesel engines. The experiments were carried out under the non-evaporating condition at ambient density(8.8, $15.6 kg/\textrm{m}^3$) and injection pressure(75, 135 MPa). The experimental method was based on a laser sheet scattering technique. Spray tip penetrations of bio-diesel fuel were longer, on the whole, than those of conventional diesel fuel, except for lower injection pressure(75 MPa) under lower ambient density$(8.8 kg/\textrm{m}^3)$. But spray near angle and spray far angle of bio-diesel fuel were smaller than those of conventional diesel fuel, implying spray angle is related to the growth rate of spray tip penetration. The experimental results of spray tip penetration agreed well with the calculated values by the Wakuri et al.'s correlation based on the momentum theory.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1069-1077
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• 2008

레이저와 카메라를 이용한 레일 마모도 측정 시스템은 정확한 마모도 측정을 위하여 레일에 조사된 레이저의 영역을 왜곡 없이 획득하고 이를 레일 단면과 정밀하게 일치시키는 과정이 매우 중요하다. 그러나 기존의 레일 마모도 측정 시스템은 빗물 등의 레일 위에 이물질이 있을 경우와 온도와 같은 측정 환경에 민감하게 반응하는 레이저의 특성으로 인하여 오차가 발생할 수 있으며 특히 외부에서 유입되는 태양광, 등과 같이 레일에 조사된 레이저와 같은 파장을 가지는 빛의 간섭에 의하여 레일에 조사된 레이저 영역 추출에 한계를 가진다. 또한, 2차원 상의 좌표 값으로 표현되는 추출된 레이저 영역을 레일단면에 맵핑시키는 과정에서 발생하는 기하학적 왜곡과 변형으로 측정 정밀도에 대한 한계가 발생하는 문제점을 가지고 있다. 본 논문에서는 레일 마모도 측정을 위하여 카메라로부터 입력되는 1메가급 해상도의 영상을 초당 480 프레임의 속도로 실시간 처리할 수 있는 DSP와 FPGA가 탑재된 고성능 영상처리보드를 개발하고 이를 기반으로 각 프레임에 대한 2D 영상 데이터를 3차원 상의 데이터로 맵핑함으로써 정밀한 레일 마모도 측정 방법을 제안하고자 한다. 획득한 영상으로부터 레일에 조사된 레이저의 영역을 정확하게 추출하기 위하여 웨이브렛 기반의 영상 알고리즘을 적용하고 2차원 상의 좌표값으로 표현된 레이저 영역을 카메라 모델과 투시 변환을 이용하여 레일의 단면에 정확하게 위치시킴으로서 ${\pm}0.5mm$ 이하의 오차범위를 가지는 고정밀 레일 마모도 측정 시스템을 개발하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2001년도 춘계학술대회 논문집
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• pp.193-199
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• 2001

In this study, the carbody design of the rubber tired AGT(Automated Guide-way Transit System) under development by KRRI was numerically analysed to evaluate its structural strength according to the standard specifications for Korean LRT (Light Rail Transit). The numerical results showed that the detail design of the carbody was strong enough to satisfy the specifications with respect to the axial compression strength, the vertical strength and the vertical stiffness(natural frequency). However, the carbody design had some problems on the fatigue strength by twist loadings. So, it was recommended that the carbody design should be modified to improve the twisting strength by reinforcing the front end structures.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.884-888
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• 2005

The interests of the government and civil business owner against the Light rail transit are increasing, it may be caused by the enterprise conception which does not consider a city circumstance that the construction plan is insensitively performed. This article present the forecast method of minimum transportation demand which secures a profitability. If It is in advance investigated the number of passenger using the existing traffic system of the area, it will be possible that the LRT project is planned on a realistic basis.

• 대한토목학회논문집
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• 제42권1호
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• pp.83-93
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• 2022

최근 도시철도 노인 무임승차제도에 대한 논란이 거세지고 있다. 이에 본 연구는 부산김해경전철의 운영적자를 재정지원 하고 있는 부산시와 김해시 소속 공무원들을 대상으로 노인무임승차제도에 관한 10년간의 의식변화를 비교·분석하였다. 부산김해경전철은 국내에서 유일하게 노인무임승차제도를 실시하지 않는 도시철도이다. 2011년 9월과 2021년 4월, 노인 무임승차제도에 대한 이해와 지식이 상대적으로 높은 지자체 공무원들의 의식 조사를 실시하여 그 변화 과정을 추적하고 행정적, 정책적 고찰을 수행하였다는 점에서 차별성을 지닌다. 분석 결과를 요약하면, 부산김해경전철 개통 전후 의식변화가 확실히 나타났으며, 개통 이후 시간이 지남에 따라 찬성과 반대가 거의 동일한 비율로 수렴하는 것으로 나타났다. 특히 개통 전에는 교통관련부서 근무경험이 없는 응답자일수록 찬성 비율이 높았으나 시간이 지날수록 근무경험이 없는 그룹도 찬성 비율이 차츰 낮아졌다. 또한 시간이 지날수록 노인 무임승차제도의 지속보다는 정책대안 모색의 필요성이 강조되었다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2292-2299
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• 2011

The CBTC(Communication Based Train Control) system, a recent train control system, is a wireless communication based train control system that is operated in the moving block system control by tracking trains in real time. In additioin, the system helps to increase the volume of traffic by shortening driving headways through controlling moving block system control. Furthermore, driverless modes are performed by controlling ATP(Automatic Train Protection)/ATO(Automatic Train Operation). In this paper, controllable elements in ATO driverless train control system, affecting comfortable ride, will be analysed and applied to CBTC train control system that developed by POSCO ICT. Finally, the test results of improved comfortable ride will be showed by appling the developed system to the Gyeong-san light rail transit test track.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.872-880
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• 2011

In terms of accessibility and time the tram rail and bus transportation system is equipped with all the benefits of. In addition, construction and operating costs than light rail trams reduce AGT, and by car from the city center by inhibiting the transport demand management, pedestrian-oriented transportation system, including city jaebuheung can expect several effects, depending on the expected introduction of trams are. Accordingly, increasing interest in streetcars and trams, and the forum is running and the green at the National Assembly, Korea Railroad Research Institute samurai tram lines in the Korean research team developed the tram is thriving. In this study, in Korea as a way to introduce a tram tram to enhance the safety and reliability challenges for the advancement and promotion of foreign tram with the safety regulations and accident cases learn safety measures to strengthen the domestic transportation. The expected introduction of the tram fits the matter at issue and the perception of citizens and the passengers can make changes to present policies, the successful national introduction of trams and safety study aims to review.

• 한국소음진동공학회논문집
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• 제22권4호
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• pp.307-317
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• 2012

The LRT(light rail transit) system, which has medium transport capacity between subway and bus is an advanced transportation system. It has many benefits like chap construction and operational cost down through driverless and flexible route planning. The rubber tired AGT(K-AGT) is a kind of LRT, which has rubber wheels and side guides. The side guides has many advantages, but brings vibration and noise problems from the friction between the guide rail and the wheels. This is the major source for the of passengers' discomfort. The purpose of this paper is to analyze dynamic characteries and running stability of the rubber tired AGT localization bogie if the AGT's speed is increased from 70 km/h to 80 km/h. The current design parameters of bogie suspension, as it is designed, was examined to satisfy the comfort index of the railway vehicle in performance test.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.799-804
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• 2005

In this work, the characteristics of train performance of Korean rubber-tired AGT system(K-AGT) are evaluated by using TPS(Train Performance Simulation) and these results are compared to those of other LRT(Light Rail Transit) systems. The performance characteristics of K-AGT was analyzed by comparing the scheduled speed and the energy consumption in case of station interval change and rail track condition change in, the scheduled construction line. In the scheduled construction line, scheduled speed of K-AGT was no difference with other systems and energy consumption was less than other LRT's. In case station intervals are increased, scheduled speed of K-AGT shows similar increasing rate and in curved and graded track conditions K-AGT has no difference in scheduled speed with other systems. As a simulation result by track condition change, when the track which is smaller than curved line of 250m dominates more than $50\%$ in whole track, K-AGT is similar to other systems to the point of scheduled speed and there is advantage in energy consumption.