• Journal of Electrical Engineering and Technology
• /
• 제9권5호
• /
• pp.1712-1718
• /
• 2014

Experimental analysis according to the plasma actuator design variables was performed in order to verify the effects of sliding discharge plasma on aerodynamic drag reduction of a high-speed train. For the study, sliding discharge plasma actuator and high-frequency, high-voltage power supply were developed and experimented to figure out the best design variables for highest ionic wind velocity which could reduce the drag force. And then, 5% reduced-scale model of a high-speed train was built for wind tunnel test to verify it. From the results, it was confirmed that sliding discharge plasma had contribution to reduce the drag force and it had the potential to be applied to real-scale trains.

• 한국철도학회논문집
• /
• 제11권5호
• /
• pp.513-518
• /
• 2008

새로운 운송시스템은 기술개발뿐 아니라, 경제성 확보가 필수적인 요소이며, 튜브운송시스템은 현재 개발 초기 단계로서 다양한 기술이 제안피고는 있으나 세계적으로 상용화된 사례는 없는 실정이다. 따라서 튜브운송 시스템의 개념설계 단계에서부터 경제성을 고려한 성능조건을 설정하고 이를 설계 요구조건에 반영함으로써 사회적으로 유의미한 기술의 개발이 가능할 것으로 생각된다. 국내에서 과거 대중교통문제를 해결하기 위하여 신 교통수단을 도입하였으나 도입당시 기술적 문제 및 경제성을 고려하지 않음으로 경쟁력 있는 교통수단이 되고 있지 못한 실정이다. 그러므로 본 연구에서는 튜브운송시스템의 개념설계를 위한 설계 요구조건 확립을 위하여 경제성을 고려한 튜브운송시스템의 성능조건을 도출고자 하였다. 이에 우선적으로 타당성 분석방법론을 검토하고 이에 따른 비용/편익을 산출하였으며 수단간 비교분석 및 사례분석을 통하여 화물운송을 위한 튜브운송시스템 최소 성능조건을 도출하였다.

• International Journal of Contents
• /
• 제14권4호
• /
• pp.39-50
• /
• 2018

This paper analyzes the existing transportation systems of Nigeria and Korea and proposes a new railway and roadway design for Nigerian cities. The research findings and feasibility study revealed that the state of Nigeria's transportation system was critical as was its market segment, infrastructural deficit and financial requirement needed to implement a smart transportation system. The dilapidation of the existing infrastructure coupled with poor maintenance culture and limited public transport services has hindered the economic growth of Nigeria and its cities. A case study of Korea and Japan shows some possible solutions to Nigeria transportation challenges. Analytical and descriptive methods were used to critically assess the infrastructural challenges, movement, and convenience. The study proposed the design of a new intercity railroad and roadway across Abuja, Enugu, Lagos and Port Harcourt cities. The proposed designs have been established to be an innovative solution with advanced benefits over the current system. The implementation of the proposed designs is estimated to cost about US$(77,832,027,719) across the study areas. Thus, the discussion, conclusion, and recommendations given present a proposal to the Nigerian government on the possibility of solving the Nigerian intercity railroad and roadway transportation challenges across Abuja, Enugu, Lagos and Port Harcourt cities through smart designs.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2010년도 춘계학술대회 논문집
• /
• pp.371-379
• /
• 2010

2005년 교토의정서가 발효되면서 세계는 에너지절감 및 저탄소 수단위주의 대중 교통정책이 펼쳐지고 있다. 우리나라는 현재 세계 8위의 탄소배출국이며 2013년부터는 온실가스 감축의무대상국에 포함될 예정이다. 본 논문에서는 국가교통시설의 투자전략을 고효율 및 저탄소 정책을 달성할 수 있도록 녹색교통수단인 철도를 중심으로 대중교통체계를 개편하기 위해 다양한 추진전략을 제시하였으며 추진전략은 크게 속도, 접근성, 도시개발, 유비쿼터스 측면에서 고려하였다. 본 연구에서 제시한 4가지 주요전략은 1시간철도, Seamless 30, Rail Urbanism, U-Rail 로 정의 하였으며 1시간철도는 1시간대 연결 가능한 고속철도망 구축, Seamless 30은 주요 거점역까지 30분 이내 접근, Rail Urbanism은 철도기반의 도시계획 실현, U-Rail은 Ubiquitous 기반의 철도서비스 제공이라는 목표를 설정하였다. 각 추진전략별 세부추진과제를 수립하여 교통분야의 전문가를 중심으로 AHP 분석을 실시하였으며 각 세부추진과제별 추진 우선순위를 도출하여 단기, 중기, 장기로 구분하여 Action Plan을 제시하였다.

• 한국철도학회논문집
• /
• 제17권2호
• /
• pp.100-105
• /
• 2014

해중철도 부근에서 테러나 사고에 의해 수중폭발이 발생하였을 경우, 함체에 치명적인 손상을 가할 수 있으므로, 충분한 강도를 확보해야 한다. 본 연구에서는 설계 목적으로 해중철도 인근에서 수중폭발이 발생한 경우, 경험에 기초한 공식을 이용하여 충격압을 추정하고, 충격압에 의한 해중철도의 응답을 해석할 수 있는 간이 해석 방법을 제안하였다. 해중철도 함체를 탄성 지지된 보로 이상화하고, 초기 최대 충격압이 작용하는 보에 대해 정적 유한요소해석을 실시한 후, 동하중 계수와 조합함으로 최대 변위 및 굽힘 모멘트를 계산한다. 간이해석 결과는 상용 유한요소해석 소프트웨어를 이용한, 시간에 따른 과도응답해석 결과와 비교하여 양호한 일치를 보임을 확인하였다.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2008년도 추계학술대회 논문집
• /
• pp.45-49
• /
• 2008

The monorail system as new transportation system mostly has being constructed as an elevated construction. In particular, in case of construction to elevated structure in the center of a city, it is important to decision for a monorail station to be considered the minimization. We must purchase the required lands prior to design the monorail stations because of separation of a platform and a waiting room. So We can exclude the problem that it have too close between a monorail station and the other building. Therefore the standard width and elevation of the monorail station shall be considered the efficient execution, economic and transportation. We have many thing to resolve as the plan of minimization to the station of monorail. But we know the ultimate in environmentally friendly transportation, of course, is our monorail system and we are positive as to a popular transportation craze.

• 전기학회논문지
• /
• 제67권12호
• /
• pp.1729-1734
• /
• 2018

Recently, interest in environmentally friendly transportation systems has been increasing, and study on railway systems has been aggressively conducted. Therefore, lots of studies have been done in railway advanced countries to improve performance of PWM converter. The research on the PWM converter for railway vehicle was mainly carried out on the converter mounted on railway vehicle such as the high-speed railway and metropolitan railway. In also, a lot of study has been carried out to improve converter performance installed in the ground. The high-capacity transform used in this paper converted from AC 22.9kV to AC 590V. The converter changed from AC 590V to DC 950V. In general, in the case of rectifier, the DC power supply system has a negative impact on inverter control characteristics because it can not avoid the pulsating component. In this study, it was performed current control for high-capacity converter using Matlab Simulink. The PWM converter is normally performed through the voltage and current at starting mode, powering mode, and braking mode. In the light-load test and the on-line test, we have studied for the PWM converter characteristics. Using this research, we have founded that the converter has excellent performance.

• 한국전산유체공학회지
• /
• 제20권3호
• /
• pp.62-69
• /
• 2015

Pressure change inside cabin as well as in tunnel has been calculated to assess the passenger pressure comfort of high-speed train. $C-STA^{TM}$, a CFD program based on axi-symmetric Navier-Stokes equation and Roe's FDS has been used to simulate the pressure change in tunnel during a high-speed train passing through it. To present the relative motion between the train and the tunnel, a modified patched grid scheme based on the structured grid system has been employed. The simulation program has been validated by comparing the simulation results with field measurements. Extensive parametric study has been conducted for various train speed, tunnel cross-sectional area and tunnel length to the pressure change in cabin. KTX-Sancheon(KTX2) high-speed train has been chosen for simulation and the train speed have been varied from 200 km/h to 375 km/h. The tunnel length has been varied from 300 m to 7.5 km and tunnel area from $50m^2$ to $120m^2$. Total 504 simulations have been conducted varying the parameters. Based on the database produced from the parametric simulations, minimum tunnel cross-sectional area has been surveyed for various train speeds based on Korean regulation on pressure change in cabin.

• 한국안전학회지
• /
• 제31권5호
• /
• pp.141-148
• /
• 2016

There exists required safety integrity level (SIL) to assure safety in accordance with international standards for every electrical / electronics / control equipment or systems with safety related functions. The SIL is allocated from lowest level (level 0) to highest level (level 4). In order to guarantee certain safety level that is internationally acceptable, application of methodology for SIL allocation and demonstration based on related international standards is required. Especially, in case of the SIL allocation method without determining of quantitative tolerable risk, the additional review is needed to check whether it is suitable or not is required. In this study, the quantitative risk reduction model based on the safety integrity allocation results of railway platform screen door system using Risk Graph method has been examined in order to review the suitability of quantitative risk reduction according to allocated safety integrity level.

• 전기학회논문지
• /
• 제64권6호
• /
• pp.948-953
• /
• 2015

In this paper, we studied the environmental requirements for the railway transponder system. The transponder system is comprised of a reader installed beneath the train, a tag installed on the track, and a portable programmer. Among them, the transponder tag should be designed to withstand harsh environments, such as wide operating temperature range, mechanical shock and vibration, etc. To validate stable and reliable service under railway conditions, we carried out environmental test for transponder tag. We then installed the tags on the Honam high-speed test line.