• Journal of the Korean Society for Railway
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• v.15 no.3
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• pp.294-299
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• 2012

Rail transport has been considered an environmental-friendly transport mode compared with other transport modes such as ship, truck, and aircraft. However, air pollutions emitted by diesel locomotives have emerged as social issues. In addition, the railway industry may not be able to avoid a duty of alleviating greenhouse gases emission owing to the Korean government policies for green growth which is an economic paradigm that simultaneously pursues growth and environmental improvement. Moreover, rising oil prices has burdened a train operating company. The purpose of this paper is to develop a methodology of determining an economical speed of diesel freight locomotive from the viewpoint of the train operating company. In the methodology, we first define an operational cost function based on various cost factors and then suggest formula to calculate an economical speed of diesel freight locomotive. To estimate the influence of cost factors such as diesel price, carbon taxes, and time costs on the speed of diesel freight locomotive, sensitivity analysis was conducted.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.593-598
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• 2000

Experimental study is conducted to clarify the pneumatic characteristics of brake system for freight train. Empty-load and diaphragm brake systems are mainly installed in the freight trains owned by KNR(Korean National Railroad). Experimental train set is composed of sixteen freight train and one diesel locomotive that are now in use. From the experimental results, in case of commercial brake, empty-load brake system responds to the brake command more slowly than the diaphragm brake system. But, in case of release command, the response time of diaphragm brake system is shorter than that of empty-load one. In the emergency brake test, the decreasing rate of brake pipe pressure of tenth car is almost same that of decreasing rate of commercial brake service.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.12
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• pp.1739-1747
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• 2001

Experimental study has been conducted to clarify the pneumatic characteristics of brake system for freight train and enhance the performance of diaphragm valve. Empty-load and diaphragm valves are installed in pneumatic brake system for freight trains of KNR (Korean National Railroad). Experiments are conducted by using freight train and diesel locomotive in operation. From the experimental results. new quick release valve shortens release time after brake application. In case of normal brake application, the release time is shortened to 34% of the original diaphragm valve. Reducing the release time of pneumatic brake system will be helpful to assure brake-release application and save maintenance efforts like wheel grinding.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.525-532
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• 2001

Experimental study has been conducted to clarify the pneumatic characteristics of brake system for freight train and enhance the performance of diaphragm valve. Empty-load and diaphragm brake systems are mainly used in the freight trains of KNR (Korean National Railroad). The train set is composed of thirty freight cars and diesel locomotive. From the experimental results, new quick release valve shortens release time after brake application. In case of normal brake application, the release time is short by 34% of that of original diaphragm control valve. It will be expected to assure brake-release application and reduce maintenance efforts.

• Journal of Environmental Health Sciences
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• v.34 no.2
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• pp.153-160
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• 2008

Personal noise exposure was assessed in railroad operators working in 40 operation units including the Gyeongbu line, Honam line, and Janghang line between 2004 and 2006. 8-hour TWA were assessed based on the MOL (Ministry of Labor) guideline on noise evaluation, and 17% of these measurements exceeded 85 dBA while 70% were over 80 dBA. When the ACGIH TLV is adopted, 40% of measurements were over TLV (85 dBA). The noise exposure risk of railroad operators was higher for diesel locomotive operation and longer operational distances; in addition, the risk was higher for passenger car operation compared to freight car driving. Given that in Korea, over the past 30 years diesel locomotives have provided most of the railway's motive power and that hearing protective equipment is not likely to be used by workers during operation, railroad operators are at a high risk of noise-induced hearing loss. The result of audiometric test among 568 railroad operators showed that 32.6% of those tested had a hearing threshold shift of more than 40 dB. In conclusion, this study calls for more fundamental measures including noise control countermeasures within the operation areas, development of equipment that generates less noise and adopting limitation on the operation distance for a work shift.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.158-166
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• 2007

After constructing the high-speed railroad, KORAIL acquired advanced maintenance techniques about Rolling-stocks. Also RCM theory is applied to maintenance field like as inspection period and method. In the meantime, the development of the maintenance methode for Rolling-stock is slow when it compares to the components and system technology. For this reason KORAIL tries to build the optimal maintenance system which can lead the Rolling-stock maintenance technique. The existing vehicle except High Speed train KTX are separated to electric motor car, electric locomotive, diesel locomotive, diesel car, passenger car and freight car. The inspection period and methode for existing vehicles which mentioned above will be examined and the optimal Rolling-stock maintenance technique will be applied.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.645-652
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• 2018

Recently, as South Korea has joined the OSJD, the rules of the OSJD need to be applied to South Korea. Therefore, the railways are connected to the continent railway in terms of software, but the railway systems in neighboring countries have been developed and operated for a long time, and are quite different with some restrictions in terms of hardware. Therefore, this study analyzed the current railway systems of neighboring countries' based on the TSI used in Europe for technical interoperability. A real operation with the operation models within the specific route was assumed and vector functions for the Infrastructure vector & Rolling stock vector were produced. The IOP value was calculated by working out the interfacing matrix value between the infrastructure vector and rolling stock vector. As a result of calculating the IOP in a specific route, which is from Busan South Korea to Vladivostok with the diesel locomotive hauling freight cars, the value was only 22%, which is fairly low in terms of the interoperability. In other words, there are 77.8% restricting items preventing their interoperability. Such restricted causes should be improved to increase the technical interoperability in the long term. Moreover, and when railway systems are constructed and manufactured, it is important to keep IOP 100% to increase the operating efficiency in continental railways.