• Journal of the Korean Society for Railway
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• v.11 no.5
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• pp.513-518
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• 2008

Currently, urban areas face congestion problems that diminish personal mobility and freight-transport productivity. An increasing number of experts suggest that separating freight traffic from passenger traffic makes sense in terms of economics, the environment, and safety. Some experts suggest that tube transportation is the solution. The objective of this paper is to evaluate the potential benefits and limitations of tube transportation system as a viable mode of transport that can alleviate congestion on roadways. Specifically, this research employs theoretical and practical method identifying, evaluating, and selecting appropriate freight pipeline systems; evaluating the technical and economic feasibility of tube transportation; and estimating environmental, energy, and safety benefits.

• Journal of the Korean Society of Systems Engineering
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• v.6 no.1
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• pp.53-59
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• 2010

본 논문은 전세계적으로 신교통시스템으로 연구되고 있는 튜브운송시스템에 대한 개념과 화물용 튜브운송시스템의 운영개념서 및 운영요구사항의 개발에 관한 것이다. 철도시스템의 개발 초기에 시스템의 정확한 운영개념을 확립하고 이를 기반으로 시스템에 대한 사용자의 명확한 사용자 요구사항 및 운영요구사항을 도출하는 과정은 매우 중요하며, 시스템의 개발 초기 단계 측 개념설계 단계에서 반드시 수행되어야 한다. 본 논문을 통해서 문헌적인 운영개념서의 형식에 대한 조사, 특징, 그리고 현실적인 운영상황을 고려한 화물용 튜브운송시스템의 운영개념서를 제안하였다. 운영개념서를 통해서 사용목적, 운영시나리오, 비상상황 등의 정보가 식별하였으며 이를 바탕으로 시스템의 운영요구사항서를 개발하였다. 개발된 운영개념서 및 운영요구사항서는 확인된 사용자 요구사항 및 시스템 요구사항으로 구체화 되며, 시스템 아키텍처의 참고문서로서 활용될 수 있다.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.139-150
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• 2010

Recently, full-scale research about a passenger tube train system is being progressed as a next-generation transportation system in Korea in light of global green technology. The Korea Railroad Research Institute (KRRI) has commenced official research on the construction of a tube train system. In this paper, we studied various parameters of the tube train system such as the internal tube pressure, blockage ratio, and operating speed through computational analysis with a symmetric and elongated vehicle. This study was about the aerodynamic characteristics of a tube train that operated under standard atmospheric pressure (open field system, viz., ground) and in various internal tube environments (varying internal tube pressure, blockage ratio, and operating speed) with the same shape and operating speed. Under these conditions, the internal tube pressure was calculated when the energy efficiency had the same value as that of the open field train depending on various combinations of the operating speed and blockage ratio (the P-D relation). In addition, the dependence of the relation between the internal tube pressure and the blockage ratio (the P-${\beta}$ relation) was shown. Besides, the dependence of the relation between the total drag and the operating speed depending on various combinations of the blockage ratio and internal tube pressure (the D-V relation) was shown. Also, we compared the total (aerodynamic) drag of a train in the open field with the total drag of a train inside a tube. Then, we calculated the limit speed of the tube train, i.e., the maximum speed, for various internal tube pressures (the V-P relation) and the critical speed that leads to shock waves under various blockage ratios, which is related to the efficiency of the tube train (the critical V-${\beta}$ relation). Those results provide guidelines for the initial design and construction of a tube train system.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.3
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• pp.377-385
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• 2018

Super-speed vacuum tube system, where the air resistance is minimized to obtain high speed of the vehicle, is considered to be a viable alternative transportation system. Air-tightness is one of the most important design requirements of the system, because the internal pressure of the system needs to be maintained significantly lower than the atmospheric pressure. This study performed an experimental test, where a series of concrete tube specimens were applied by external loads to induce cracks and the effective air-permeability of the cracked tube structures were measured. The test results indicates that the information on the length and the width of the load-induced cracks are not enough to anticipate the system air-tightness, whereas the load-induced displacement has higher correlation with the systems air-tightness. Based on these results, a direction of future research for effect of the load-induced cracks on the system air-tightness is suggested.

• Journal of the Korean Society of Systems Engineering
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• v.6 no.2
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• pp.29-35
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• 2010

In general, an Architecture of a system is embodied as applied results of a requirement analysis of a system in early development phase. These efforts play a important role in analyzing and understanding a system considering operational, functional, and physical view and deriving a correct solution before developing the system. In this paper, the architecture of the Tube Transportation System(TTS) known as the new transportation system in Railway Domain is depicted by performance parameter has already developed. The existing performance parameters are shown by a variety of types with many meanings rather than types of general requirements refined. As these early performance parameters have analyzed and complemented to a level of requirement by requirement managers and other domain specialists, the architecture of the Tube Transportation System was developed systematically and then system requirements will be drawn up definitely. The presented architecture will provide a framework of developing a TTS and also offer an information in performance analysis of TTS.

• Journal of the Korean Society of Systems Engineering
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• v.5 no.2
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• pp.17-26
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• 2009

This paper is about that case study of the Tube Transportation System that the new transportation system offering passenger and logistic service in a metropolis having plenty of the floating population or between medium-sized cities, and solving large issues like terrible traffic jams and environmental problems etc. in this region. Also it presented that elicitation results of performance parameter and the categorization system of it applying a systematic analysis methodology. By the medium of this paper, It showed that definition, case study, performance parameters, and the categorization system of parameters of a general tube transportation system before developing requirements of a specific tube transportation system. From now on, it will come in pretty handy in systems engineering of activities to establish a concept of a new tube transportation systems and develop requirements.

• Computational Structural Engineering
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• v.23 no.3
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• pp.87-96
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• 2010

• Journal of the Korean Society for Railway
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• v.11 no.3
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• pp.59-71
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• 2008

• Journal of the Korean Society for Railway
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• v.17 no.3
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• pp.186-192
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• 2014

In this paper, a reliability analysis is performed where the pressure change inside a concrete tube is probabilistically estimated considering the uncertainties inherent in the material and the system discontinuity. A set of uncertain quantities related to the equivalent system air permeability and the atmospheric pressure, are defined as random variables with specific distribution. The pressure change inside a concrete tube is then probabilistically described using both analytical and simulation approaches. The reliability analysis confirms that the geometric configuration of a concrete tube needs to be changed from the initial configuration obtained from the deterministic analysis.

• Journal of the Korean Society for Railway
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• v.13 no.5
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• pp.516-520
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• 2010

Parametric study has been conducted to calculate the capacity of vacuum pump system that will be used to maintain the pressure of the tube structure under atmosphere level. Recently many railroad researchers pay attention to the tube train system as one of the super high speed transportation system. To achieve the super high speed, the inside of tube system should be maintained at low pressure level. In the low pressure environment, it is well known that air resistance of train is drastically decreased. Vacuum pump system will be used to make low pressure state for tube structure, exhaust the leakage air and supplement additional vacuum pumping. As results of these studies, we get the lump capacity of vacuum pump for various parameters. These results can be applied to analyze the effects of the reduction of air resistance.