• Proceedings of the KSR Conference
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• 2009.05a
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• pp.628-635
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• 2009

To assure the safety of urban railway train, it is necessary to observe the specified driving principles under an essential condition during running on tracks. These principles arises from a great deal of experience for a long time and include safe distance between trains, the railway signaling, block system, regular block of the highest priority and driving prohibition of simple railway vehicle in the main track, etc. Therefore, it is important to apply these principles to domestic urban railway driving regulations and railway vehicle driving regulations. However, domestic urban railway administrator established his own operation rules within the regulation. In this study, domestic urban railway administration's own rules are examined and the appropriate driving regulation on the safe driving principles is proposed.

• Proceedings of the KSR Conference
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• 2001.05a
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• pp.431-436
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• 2001

Rockfall has long been a serious problem, especially derailment of train running on the track in mountainous regions. The purpose of this study is to suggest the reasonable items of check and evaluation to railroad rock slopes for safe maintenance and management of rockfall-worried railroad sites. Therefore, main and sub items were extracted from the survey of foreign and other authorities' cases and evaluation table (temporary) composed of items classified by important degree was suggested. To evaluate the availability and reasonability of items, statistical analysis based on field investigation namely SMR(Slope Mass Rating) and explanation values was carried.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.574-579
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• 2003

In this study, a measuring system for performance of pantograph was developed. The measuring system was installed on the prototype high speed train and measurement has been conducted during running on the test track. The measuring system is composed of video monitoring system and telemetry & data processing system. It can monitor the hazard behavior of pantograph and measure acceleration and vertical force of the pan head. Owing to the measuring system, performance of pantograph and safety of interface system of pantograph and catenary is evaluated.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.146-151
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• 2005

Main parameters of wheel-rail combination are investigated by profile analysis. A rolling radius difference is one of the main characteristics that describe a contact between wheelset and railway track, which in turn defines the dynamic behavior of a wheelset. This paper describes functional relation between lateral wheelset displacement and rolling radius difference or conicity on new/worn wheel of existing narrow gauge vehicle. Information about curving behavior and running stability are given by this both relations. The optimal wheel profile for railway vehicle with narrow gauge is adopted through this analysis. And, the applicable limit value of conicity which is used in order to do dynamic simulation of vehicle is presented.

• International Journal of Railway
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• v.6 no.3
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• pp.107-111
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• 2013

In order to constrain the railway roadbed settlement which causes track irregularity, and thus threats running stability and ride quality, advanced Back-to-Back (BTB) reinforced retaining wall was numerically analyzed as railway roadbed structure. This study is intended to improve conventional Back-to-Back reinforced retaining wall as the technology which would reduce the roadbed settlement in a way of constraining the lateral displacement of its prestressed vertical facing and inducing arching effects in roadbed (backfill) placed between masonry diaphragm wall and vertical facing. As a result of numerical analysis, it was found that the roadbed settlement was reduced by 10% due to the prestressed vertical facing and embedded masonry diaphragm wall of the advanced Back-to-Back reinforced retaining wall system.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.1
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• pp.114-120
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• 2012

Eco-driving technique for electric vehicles (EVs) is investigated in this paper. Many findings on EVs have been reported; however, they did not deal with eco-driving from the viewpoint of theoretical study. The authors have developed an energy-saving driving technique - the so-called "eco-driving" technique based on dynamic programming (DP). Optimal speed profile of an EV, which minimizes the amount of total energy consumption, was determined under fixed origin and destination, running time, and track conditions. DP algorithm can deal with such complicated conditions and can also derive the optimal solution. Using the proposed method, simulations were run for some cases. In particular, the author ran simulations for the case of a gradient road with a traffic signal. The optimization model was solved with MATLAB.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.43-49
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• 2006

To design railway vehicles to ensure comfortable running, ride comfort of human exposed on vibrating carbody should be considered. Also, to improve ride comfort for passenger coach, many factors should be analysed and evaluated. There are many factors as suspension characteristics of railway vehicle, track characteristics to run etc. In this paper, passenger coach sujected to test on specific routine were evaluated using test results. Test routine were divided by 13 sections to analyse more detail. And the characteristics of every section were analysed distributions of radius curves, tunnel and bridge which could give impact to ride comfort. The evaluation of ride comfort were accomplished by UIC and ISO methods.

• Journal of the Korean Society for Railway
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• v.10 no.1 s.38
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• pp.22-28
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• 2007

During the passage of the train, the railway bridge undergoes vibration and noise. The noise of railway bridge can be occurred from various sources. The wheel-rail contact, noise from machinery parts, structural-borne noise, pantagraph noise and aerodynamic noise of the train work in combination. Running train is one of the most important factors for railway bridge vibration. The repeated forces with equidistant axles cause the magnification of dynamic responses which relates with maintenance of the track structure and structure-borne noises. The noise problem is one of the most important issues in services of light rail transit system which usually passes through towns. In the present study, The vibration and noise of the LRT bridge will be investigated with utilizing dynamics responses from moving train as input data for noise analysis.

• Journal of the Korean Society for Railway
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• v.10 no.1 s.38
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• pp.67-73
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• 2007

Experiments were carried out to investigate smoke movement in platform of a subway station which currently is in service in Pusan, the second largest city in Korea. The recently constructed underground station of the "bank type" (two platforms on both sides of track) which is the popular layout of platforms in Korea, is chosen in Pusan. The smoke generator and heater are used for simulating the smoke movement at the fire break in the platform located in the 2nd basement of the station. Video recordings were used to monitor smoke lowering. In this study, the movements of smoke in the underground station are investigated under various smoke-control operating modes. Three tests wire conducted according to its operating mode of the ventilation systems in the platform: no operation of any ventilation systems, smoke extraction mode in occurrence of fire (presently running mode) and full capacity of smoke extraction where all vents are activated in the platform. The results can be used for comparing with the numerical prediction results of fire subway stations.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.544-547
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• 2000

Polypyrrole (PPy) was chemically synthesized within the pores of nanoporous polycarbonate (PC) Particle Track-etched Membranes (nano-PTM). Hollow tubules are formed because polypyrrole initially deposits on the surface of the pores walls. By running successive syntheses, we have obtained wires (filled tubules). The redox property of PPy nanotubules was investigated by cyclic voltammetry. The redox potential was lowered as much as 0.5V vs. Ag/AgC1, comparing with electrosynthesized PPy film. It suggests that an electron hopping mechanism of PPy nanotubules was improved. Electric conductivity of PPy nanotubules and nanowire was evaluated. We obtained good electric conductivity of PPy nanotubules even in the neutral state. The conductivity and activation energy were $10^1$ order at the room temperature and 25.3 meV respectively.