• International Journal of Railway
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• v.5 no.2
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• pp.71-76
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• 2012

Recently, axle load, operating speed and traffic density on railroads have had a tendency to increase and thereby cause additional pressure applied on used track. These operating conditions frequently result in service failure due to wear caused by wheel-rail contact and fatigue damage under cyclic loading. Among rail defects, the transverse crack, which has been the most dangerous type of fatigue damages, is developed from the subsurface crack near the rail running face and grows perpendicular to the rail surface. Therefore, it is necessary to investigate systematically the growth behavior of transverse crack for rail steel under mixed mode. In this study, the fatigue crack growth behavior of the transverse crack in rail steel was experimentally investigated under mixed-mode variable amplitude loadings.

• Journal of The Korean Society For Urban Railway
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• v.6 no.4
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• pp.339-350
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• 2018

The rail wear measurements in urban underground railway have been analyzed to predict the particulate matter emission caused by rail wear which is one of the major sources of particulate matter emission for underground railway systems. From the rail profile variations measured in the interval of one and half year by dedicated rail wear measuring instrument over the commercial urban underground railway line, 'line-s' which is about 45km long, the characteristics as well as the amount of rail wear have been analyzed after dividing the whole line into about 170 section with radius of curve(R). It has been concluded that the vertical wear parameter V0 and corner wear parameter C0 have been selected to represent the wear amount of straight and curved rail respectively. The amount of rail wear as well as the particulate matter emission by rail wear over the whole line normalized by the rail length as well as the number of train has also been deduced from the relationship between the rail wear parameters and the amount of rail cross-section area.

• Journal of Korean Society of Transportation
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• v.14 no.1
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• pp.165-177
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• 1996

Recently, many local governments suffering from traffic congestion have plans to introduce light weight (mid-size) rail transit systems, since the systems' investment costs are known to be much less than heavy rail transits such as the subway in Seoul. Most of the governments expect private partners to be involved in the systems' constructions and operations mainly because of their financial difficulties. Since the governments do not have experiences of evaluating and selecting privately financed transportation systems, they may need an evaluation guideline. This paper discusses evaluation criteria, methodologies, and procedures which will be helpful to local governments faced with evaluating light weight rail transit systems proposed by private companies.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.101-108
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• 2000

Tins paper is designed (ⅰ) to envisage the characteristics of high speed rail stations that will be in operation when the Seoul-Pusan line currently under construction is completed and (ⅱ) to assist policy makers in mapping out transportation strategies by providing insights into how advanced countries have handled problems under similar circumstances. Ultimately, tins paper intends to present alternatives of trans-modal systems in an attempt to set a direction for future policy making in the high speed rail sector. The alternatives recommended in tins report stress two important elements for maximized utility of high speed rail: One is to maintain consistency in transportation policies and the other is to attract consumers to the station areas.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1958-1963
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• 2010

Space Elevator introduced in the science fiction titled "The Fountatins of Paradise" by Arthur C. Clarke in 1979 could be attainable for the transportation of human and distribution from earth to space. Space Elevator could reduce shipping expenses and risks of the transportation system. Developing Space Elevator has to need rail technologies for the train and the rail using Carbon nanotube cable, installation of rail appropriated for Earth-orbiting. For this reason, rail technologies for developing Space Elevator will be suggested by this study through the case study.

• Journal of the Korea Institute of Building Construction
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• v.12 no.6
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• pp.596-606
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• 2012

In recent years, LEED-NC (Leadership in Energy and Environmental Design for New Construction) has become one of the most widely adopted environmental certification systems in the United States. However, according to some researchers, the adoption of the LEED-NC is perceived to add to construction cost and duration compared to conventional building standards. Therefore, it is necessary to examine the economic benefits of LEED-NC to consider how it can be applied worldwide. This study focuses on the impact of LEED-NC on the appraised unit value of parcels in San Francisco County based on the number of LEED-NC Public Transportation Access (PTA) qualified buses, light rail and commuter rail stops, distance to the closest bus, light rail and commuter rail stops, zoning class and parcel size. As a population of interest, San Francisco County was chosen since it is known as a region with well-organized transportation systems including bus, light rail and commuter rail systems. According to the correlation results, this study shows that the appraised land value is significantly affected by LEED-NC PTA, and is correlated to a higher appraised unit value of land parcels.

• International Journal of Railway
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• v.6 no.4
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• pp.148-154
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• 2013

This article has tried to review the maximum contact stresses in the contact area of the wheel and rail as a result of lateral movement of the wheel on rail by taking advantage from Hertz theory. Since wheel movement on rail is accompanied by lateral movement due to wheel profile conisity, so the contact point of wheel and rail is not constant and the contact stresses are therefore changeable in every single moment. Since the shape of rail profile and rail inclination, wheel diameter and the mechanical properties of the wheel and rail are effective on the stresses of contact area, these parameters have been studied by applying Hertz theory. This article aims to calculate the contact stresses in different parts on the wheel surface by using Hertz theory.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1647-1656
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• 2007

With the growing international consensus regarding sustainable development of transportation, the plan of transportation infrastructure needs to meet various requirements toward enhancing environmental conditions. Accordingly, the upcoming long-term plan of high-speed rail network has to be reflecting the sustainability of transportation systems. In this paper, we propose methodologies based on multi-attribute utility theory for determining priorities of sustainable high-speed rail investment. The proposed methodologies identify indicators for sustainable transportation systems such as economic, environmental, social, and transportation-related ones and then, explain the way how to evaluate the overall sustainability by comparing the relative importance among indicators. This will help transportation agencies to prioritize high-speed rail investment toward sustainable transportation systems.

• Transportation Technology and Policy
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• v.13 no.3
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• pp.66-75
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• 2016

• Journal of Korean Society of Transportation
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• v.22 no.3 s.74
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• pp.167-177
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• 2004

The Hub-and-spoke strategy is widely used in the field of transportation. According to containerization and the development of transshipment technology, it is also introduced into European rail freight transportation. The objective of this article is to develop a service network design model for rail freight transportation based on the Hub-and-spoke strategy and efficient algorithms that can be applied to large-scale network. Although this model is for strategic decision, it includes not only general operational cost but also time-delay cost. The non-linearity of objective function due to time-delay factor is transformed into linearity by establishing train service variables by frequency. To solve large scale problem, this model used a heuristic method based on decomposition and three newly-developed algorithms. The new algorithms were examined with respect to four test problems base on the actual network of European rail freight and discussed the accuracy of solutions and the efficiency of proposed algorithms.