• 디지털융복합연구
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• 제12권10호
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• pp.283-289
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• 2014

PRT(Personal Rapid Transit) 시스템은 자동차를 대체할 수 있는 지속 가능한 친환경 미래교통 수단으로 최근 국내외적으로 활발한 연구가 진행 중이다. 이러한 PRT 시스템의 중요한 특징 중 하나는 저비용으로 건설 운영될 수 있다는 것이다. 본 연구에서는 PRT 주행선로에 대해 차량의 주행안정성을 고려한 최적 평면 선형에 대한 기초 연구를 수행하였다. 설계 최고속도로 주행 시 곡선반경, 완화곡선 길이, 캔트(편경사)와 같은 주요 매개변수들에 대해 차량동역학 해석을 수행하였으며 최적선형 설계(안)을 제시하였다. 해석결과, 이론값을 만족함을 알 수 있었으며 기준 완화의 가능성도 확인할 수 있었다.

• 대한핵의학회지
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• 제27권2호
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• pp.233-238
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• 1993

Esophageal motility was evaluated from the analysis of 10 consecutive swallows using liquid bolus containing 0.5 mCi of $^{99m}Tc$ tin colloid. We have reviewed our experience of esophageal transit study in the 20 normal volunteers and 55 patients with dysphagia that was not related to mechanical obstruction. The purpose of this study is to measure the esophageal transit in normal subjects and in patients with various esophageal motility disorders. The overall sensitivity and specificity of radionuclide esophageal transit study in detecting esophageal motor abnormality were compared with manometric results as a gold standard, which were 80% and 100% respectively. Radionuclide transit study is a safe, rapid, noninvasive test and suitable as a screening test for esophageal motor disorders.

• 한국철도학회논문집
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• 제9권5호
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• pp.539-543
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• 2006

We need to make the standards of maintenance information for urban transit to reduce the cost to maintain the information and to share the information with maintenance workers. It is enable to do systematic maintenance for urban transit by using the information system based on the standardized information. In this paper we propose the major items to standardize and the methods to lay out the standard schemes to enable structured maintenance. We present the 4 items, bill of material, material classification, accident/fault classification, electronic document, to standardize. And we propose how to implement the information system for urban transit based on the standardized information. We describe the implemented information system in two parts; a rolling-stock and an infrastructure part. And also we describe the result of survey to evaluate the system installed at Seoul Metro and Seoul Metropolitan Rapid Transit.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.909-914
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• 2005

본 논문에서는 PRT (Personal Rapid Transit)의 원격 제어를 위한 무선 채널 환경에서 안테나 선택 기법을 적용한 MIMO-OFDM 시스템에서 귀환 정보의 양을 줄이는 효과적인 기법을 제안한다. 제안한 기법은 PRT 무선 채널 환경에서 차량에 할당된 주파수 채널 상관도에 따라 부반송파들을 그룹 단위로 나눈 후 그룹의 중앙에 위치한 부반송파의 채널 값을 기준으로 해당 부반송파 그룹의 송신 안테나를 선택한다. 모의실험을 통해 해당 그룹의 부반송파들의 수를 적절히 선택하면 적은 성능의 열화를 가지고도 귀환 정보의 양을 크게 줄일 수 있음을 확인하였다. 특히 PRT 무선 채널 환경에서 차량과 제어기지국 사이의 귀환 채널의 전송률이 고정된 경우, 차량의 속도가 증가할수록 제안한 기법이 더욱 좋은 성능을 보였다.

• International Journal of Railway
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• 제5권1호
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• pp.1-9
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• 2012

Reliability means that a product maintains its initial quality and performance at a certain period of time (time, distance, cycle etc) under given condition without failure. The given conditions include both environmental condition and operating condition. Environmental condition means a common natural environment such as temperature, humidity, vibration, and working condition means an artificial environment such as voltage, current load, place for installment, and hours of use, which occurs during the life of the product. In the field of railway vehicles, it is mandatory to use a part with the proved reliability as the extension of the life of vehicle become highly necessary. But the reliable assessment method for the reliability of the part is insufficient. If the reliability of the railway vehicle parts could be assessed by using the field data, the reliability of the entire system could also be evaluated reliably. In this study, life span of micro-switch for master controller is analyzed and prediction is performed based on its field data given by an operator considering the special circumstances of railway vehicles such as the operation of a large number of trains on the same line.

• 조명전기설비학회논문지
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• 제29권5호
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• pp.65-70
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• 2015

Lightning is one of hazards affecting the rapid-transit railway system. There are two effects, which are direct lightning surge to electric car line and induced lightning surge. Protection methods for the direct lightning surge are studied with various occasions, however, study of induced lightning surge is insufficient in spite of a large or small effects. In this paper, it is analysed the way that serge voltage is induced to electric car line by lightning strikes. By modeling the propagation process and the coupling phenomenon of electromagnetic wave produced by lightning strikes, it is achieved to make integrative circuit model combined with existing electric car model. The study is conducted into three different waveform of electromagnetic wave produced by lightning; rectangular wave, double exponential distribution wave, triangle wave. It is also simulated that the inducing serge is coupled to electric car line in an arbitrary location. The simulation results in that, when rapidly changing rectangular wave is supplied, maximum power is induced to electric car line.

• 국제학술발표논문집
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• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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• pp.426-431
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• 2011

The quality of performance evaluation on engineering consultants that provide design-related technical services is difficult to be measured, and only a handful of papers discussed the quality during the design stage. Although design cost is relatively far less than construction cost for a project, the decisions made in the design phase have a significant impact on the final products of the project, especially for large public construction projects. Therefore, this research focuses on reviewing and then establishing a performance evaluation framework for the consulting firms that execute detailed design and provide technical services for the Taipei Rapid Transit Systems (TRTS). By interviewing experts, this study first established a set of indicators to evaluate these firms' performance. Then, those indicators were incorporated into the four aspects of balanced scorecard (BSC) to establish the architecture of the evaluation mechanism. The weight of each indicator was calculated by analytic hierarchy process (AHP) from a survey conducted among experts. The results showed that the top-three indicators were quantity take-off, functions conformity, and budgeting. The framework of performance evaluation established by this study can be applied to measure service performance during the design stage. It not only facilitates the monitoring of consulting firms, but also helps to reduce unnecessary change orders and disputes during the construction stage.

• 한국자동차공학회논문집
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• 제21권4호
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• pp.144-152
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• 2013

PRT(Personal Rapid Transit) system is a new transportation system which will meet increasing demands of traffic in Korea. It is also an environment-friendly transportation and automatically operated. For these reasons, researches on the PRT system are actively undergoing, but the PRT vehicles have different forms of subway, bus, etc. There are no design standards to evaluate structural integrity, yet. In this paper, Structural design specifications are derived, which are based on the performance test standard for EMU and the ASCE-APM standards. We also perform the static and fatigue analyses by FE simulation and suggest strategies to improve an initial structure design. In addition, we derived the design specifications for energy-absorbing structures to meet the conditions of the collision scenarios predefined from a view point of operation safety.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1683-1688
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• 2008

These days, in Korea, according to improving the standard living, people generally work 5 days a week and it results more leisure hours. On weekends or in specific season, travel to mountain region around the major city is much in demand, and, in case of public transportation, the demand exceeds the supply. So, people tend to go other places, even overseas, for their holidays. The situation in Korea reflects the needs for mountainous light rail transit system with the object of convenient and rapid transport of passengers. In this paper, the guideline for mountainous light rail transit planing is proposed, and the representative mountainous light rail transit system is analyzed to choose the proper mountainous light rail transit system which adapts the demand for transportation and the terrain in Korea.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.284-290
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• 2009

최근 국내에서도 대도시의 도로 교통 혼잡과 그로 인한 환경오염으로 인해 신교통시스템의 중요성이 증대하고 있는 가운데 기존 지하철의 과중한 건설비 및 운영비 부담을 대체할 수단으로서 신교통시스템의 도입에 대해 적극적인 정책을 수립하고 있는 실정이다. 현재의 도시교통의 문제점을 해결하고 미래 도시교통의 모습을 새롭게 만든다는 의미에서 신교통시스 템에 대한 분명한 인식과 도입방안에 대한 검토가 시급한 시점으로, 신교통 차량시스템은 효율적인 서비스 제공 및 교통문제 해결을 위해 다양한 형태로 발전해 왔으며, 전용 주행로를 갖는 철도시스템의 장점인 정시성 및 안전성과 버스의 장점인 유연성을 만족시킬수 있는 시스템으로 개발되어 왔다. 본 논문에서는 신교통시스템 도입시 차량시스템 선정시 고려사항 및 기존노면 교통수단과 공용으로 주행로를 사용할 수 있는 차량시스템으로 저상굴절버스, 노면전차, GRT(Guided Rapid Transit, 유도 고속차량) 시스템의 해외운행 사례 및 시스템을 비교, 장단점을 중심으로 고찰 하고자 한다.