• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1251-1253
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• 2001

This paper presents on capacity design of DC-fed-traction system. The system is introduced including a characteristics of train, feeding network configuration, and design method of substation arrangements. Optimal design procedures is described, and program for capacity computation of the system is presented using the nodal equation, K.C.L, K.V.L, Ohm's law and superposition theory. For the proof of the proposed algorithm, we accomplished the simulation of DC traction system for HA-Nam LRT. By considering whole component in DC traction system the conclusion will be much precise.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.1
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• pp.61-67
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• 2013

The turnout point system is installed to separate the main rail track from other tracks in rail load stations. It is also important to set up the switch point system to change the direction of the turnout point, to lead and change the direction of tracks. The switch point system can be negatively affected by heavy snow during winter seasons which can cause critical safety problems. Furthermore, the maintenance and repair of the conventional system is prohibitively expensive due to its complexity and high probability of failure. In this paper, an efficient switch point system is proposed which simplifies the equipment structure and lowers the cost for maintenance and repair, while improving safety and performance of the rail road system.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2090-2100
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• 2011

Railway rail fastening system is the critical device which gives big influences to not only the vehicle driving stability and the orbit's structural stability against the impulsive load, but also the noise vibration and the ride comfort. As a part of the low-carbon green growth, the importance of the railroad industry is getting highlights on its excellent energy-efficiency and eco-friendliness. However, so far the Korea's domestic rail fastening system technology is not so good and the technical reliance to abroad is very heavy. In this study, we conducted comparative analysis on the rail fastening system with new and used one of the same type. And those systems are imported by Seoul Metro and are being used by it. With this basis, we developed the components and the materials and then, established the durability assessment methods appropriate to the Korean domestic circumstances. And through the reliability qualification test on the 7 parts of the rail fastening system, we've improved the reliability and guaranteed the 15 years of service lifetime. ($B_{10}Life15$) Establishment and standardization of Reliability Standard on the parts of the rail fastening system such as anti-vibration pads, guide-plate, screw spike made it possible to perform the internationally fair assessment. And it is thought that we can satisfy the manufactures' and consumers' needs of cost-cutting and qualification security by shortening of assessment period on rail fastening system.

• 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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• 2010.06a
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• pp.549-556
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• 2010

Reliable fast working maglev switch is one of the key technologies needed for the maglev system to be commercialized. Switch for the maglev system is large, heavy, complicated, expensive compared with that of the traditional wheel-on-rail system. This paper reports the development of a segmented maglev switch for urban transit maglev system under construction for the 6.1 km long double track maglev commercialization line in Inchon international airport in 2012. Test results along with details of the segmented maglev switch components are reported.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1743-1753
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• 2011

Seoul Metropolitan Government has performed alternative transit system, light rail transit(LRT), for settling the problems of urban public transit system based on conventional bus service and heavy rail transit(HRT). LRT projects of total 8 lines(about 73.6km), including Ui-Sinseol line, have been planned as Build-Transfer-Operate(BTO) projects. For the first LRT, Ui-Sinseol line, however, design of structure had met standard for design of HRT, because of no domestic design code for LRT when participates of Ui-Sinseol project submitted the design proposal. This case study reports a successful example of LRT design minimizing the scale of stations designed in base of HRT code. The problems, like oversized structures compared with LRT vehicles, excessive costs for construction, had been resolved through negotiations with the participates of Ui-Sinseol line. Result suggests that present and future costs for construction and maintenance of the LRT projects in Seoul be considerably reduced in advance.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.3019-3025
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• 2008

An experimental study was performed to assess the effect of diesel and JP-8 aviation fuel on the spray characteristics, performance and emissions in a single cylinder optical diesel engine. Both fuels were injected via an 8-hole solenoid-driven injector in a common-rail injection system. For better understanding of spray development, the macroscopic images were captured with high speed camera, offered evidences for the results of performance and emissions. From macroscopic spray images, the spray tip penetration of JP-8 shorter than that of diesel while spray angle of JP-8 was wider than that of diesel. It indicates that the vaporization of JP-8 is superior to that of diesel. The lower cetane number of JP-8 resulted in increased portion of premixed combustion. The IMEP with JP-8 is lower than that of diesel-fueled engine. Especially, using JP-8 has a potential for reducing soot.

• International Journal of Safety
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• v.11 no.2
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• pp.1-4
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• 2012

The falling accidents have increased in the structure and heavy industries. Therefore, a various falling prevention systems with safety block and lanyard have been supplied in order to prevent falling accidents and acquire the long life and cost down for the maintenance. However, there are not the reliable and domestic the falling prevention system until now. Almost systems were imported from U.S.A, Japan, U.K and Germany. The structural safety of the imported safety block is satisfied sufficiently, but it has heavy weight due to the cover with the aluminum and thickness. So, many workers are not feeling themselves. Thus, the aim of this work is to develop a commercial safety block that has a light weight and strength. And the cost efficiency of the system and safety for workers also will be improved remarkably.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.745-752
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• 2011

Light Rail Vehicle(LRT) is "New Transit System" that has transportation capacity as well as physical size of vehicle is in-between bus and subway. The demand of LRT system is increasing rapidly; both domestically and internationally. Reason being is that it is more economical and eco-friendly compare to existing heavy rail vehicle. Especially, Busan Subway Line 4 K-AGT (Rubber-tired LRT) being the first of its kind to start revenue service in Korea, it is very much likely that application of its demand will continue to increase. Considering its trend, study to reduce implementation cost of LRT is being pursued in many different aspects; reducing construction cost is one that aspect. In this study, on-site application of 'Up-Down Turnout System' implementation research has been carried out which can replace existing 'Left-Right Turnout System'. When safety of its type gets verified, application of this system to line which intends to use K-AGT, Shin-Lim Line and Dong-Book Line, expects to save its construction cost. This thesis paper reports ongoing research of AGT 'Up-Down Turnout System' development and main component design factors, fundamental principle, performance test result.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.2051-2057
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• 2008

This paper is a feasibility study on the calculation of operating cost in regards to the overall operation following the completion of a number of LRT lines currently in progress. Owing to the absence of operating experience in driveless LRT system at home, the difficulties lie in the assumption of the optimal operating budget applying domestic real situation. Nevertheless, with 34 years of accumulated operating experience in heavy rail transit system, Seoul Metro, the nation's biggest urban rail transit operator, performs O&M consultancy services for several on-going projects along with every effort to acquire know-how where the appropriateness of the cost estimation as a required deliverable is reviewed and a more efficient way is provided. The main focus of this study is to seek a method to calculate the optimal amount of operating expenses as well as a cost-effective alternative for possible weaknesses from the standpoint of the operator. The body of this paper discusses the five issues such as personnel cost, overhead, maintenance cost, additional purchase price, alternative investment fee from a more macroscopic point of view, and the conclusion deals with the adequacy of the reason for selection of institutions with various operating know-how.