• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.3
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• pp.196-200
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• 2010

The number of railway tunnels has been increasing rapidly. Although fires in long railway tunnels are rare, the consequences can be devastating. Prior to this study, there were no adequate time-temperature curves for the fire safety assessment of Korean railway tunnels. We studied a standard foreign time-temperature curve for which the heat rate is based on the traffic and the types of vehicles. We then proposed a hydrocarbon curve as a fire design model for railway tunnels in Korea. We examined the implications of this proposed model on railway tunnel structures using numerical analysis.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.7
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• pp.976-980
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• 2018

The traction power system is configured to transmit electricity to the vehicles through mechanical contact between the OCL (Overhead Contact Line) and the pantograph. The system measures the current collection performance of the OCL, or the OCL installation condition is examined through maintenance for commercial operation. Maintenance continues to check the conditions through visual inspection by walking and inspection vehicles. The current collection performance is divided into the percentage of arcing(%), the contact force, and the uplift. The percentage of arcing is composed of a vision based system and used to verify the performance of a new OCL. However, it is not always possible to measure the current collection performance during commercial operation, and maintenance based on human resources can not be replaced. This paper presents the minimum performance condition of video devices in the current collection system of commercial vehicles. In addition, a continuous arcing was measured, and current collection performance was examined on the traction power system at the 250 km/h. It was analyzed with a minimum duration of arc of 1 ms. The frame rate is then shown by comparing the number of frames in the image at the time intervals of the number of the arcing. It is expected that the result of this study can be used for examining the minimum performance of video devices depending on their purpose.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.879-891
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• 2009

Impedance of rails is increased by the magnetic coupling between rails and reinforcing bars in the concrete slab track. Currently, the current of track circuit has been compensated by installing the compensation capacitors on track circuit because of increasing the impedance of rails. In case of a rapid transit railway, the compensation capacitors are installed every 20[m] to compensate the current of track circuit in the concrete slab track. Because the interval of one block for a rapid transit railway is as long as 1500[m], the compensation capacitors are installed about the number of 70$\sim$75 on track circuit. However, in case the compensation capacitors are broken over the number of three, it is a problem that the amplitude of current is under standard amplitude of current which is 0.8[A]. In this paper, it was suggested installing a compensation capacitor by using resonance phenomenon on the concrete slab track. We represent the electrical model of track circuit and the four terminal network, calculate the parameters demanded for the electrical model in the concrete slab track. Also, we computed the position and capacitance of the compensation capacitor about 2040[Hz], 2400[Hz], 2760[Hz], 3120[Hz] which currently is the track circuit frequency in the Gyeongbu rapid transit railway and demonstrated the validity of it, using the Matlab and PSpice program.

• Journal of the Korean Society for Railway
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• v.13 no.6
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• pp.608-616
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• 2010

Seoul Metropolitan Rapid Transit Corporation, managing the line number 5,6,7 and 8 has inspected and maintained for the maintenance of the facilities spread in the extended 152km and 148 stations. Despite the thorough inspection for prevention of the facility failure, the failure has continuously occurred, due to the environmental factors of the underground, mechanical worn-out caused by frequent use, aging facilities, system error, negligence on use, etc. We have achieved a 53.4% reduction in the number of failure by the end of June, 2010 by breaking the conventional way of inspections and maintenance and by adopting quantitative goal management and new way of work. In this paper, we will analyze the problems of inspections and maintenance of the railway facilities, the failure reduction strategy and the performance of each strategy.

• Structural Engineering and Mechanics
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• v.45 no.6
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• pp.723-740
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• 2013

This paper presents a parametric study of reinforced concrete bridge tall piers with hollow, rectangular sections. Such piers are typically used in railway construction of prestressed concrete viaducts. Twenty one different piers have been studied with seven column heights of 40, 50, 60, 70, 80, 90 and 100 m and three types of 10-span continuous viaducts, whose main span lengths are 40, 50 and 60 m. The piers studied are intermediate columns placed in the middle of the viaducts. The total number of optimization design variables varies from 139 for piers with column height of 40 m to 307 for piers with column height of 100 m. Further, the results presented are of much value for the preliminary design of the piers of prestressed concrete viaducts of high speed railway lines.

• Journal of the Korean Society for Railway
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• v.20 no.4
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• pp.539-549
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• 2017

This paper proposes an analytical methodology of station capacity calculation on high - speed railway. Our method explicitly takes into account the effect of the number of sidings and the combination of train halting patterns (stop - stop, pass - stop, stop - pass, pass - pass) on the capacity of a station. To verify the reliability of our model, we conducted capacity analysis of selected stations using the Railsys simulator. We found that the difference in calculated capacity between our model and Railsys was less than 10%. After Monte Carlo simulation, our model was determined to be a good one. In addition, the consistency in capacity between our model and the train-path allocation program (Korea Rail Network Authority) was statistically significant.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.579-582
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• 2002

For train service, safety and reliability is an inevitable performance. Specially, turn-out system of the railway for safety because of actual part. Hence the management is strictly executed over turn-out systems of the railway. Also number of turn-out system need to monitoring systems. In this paper, the data multi-acquisition system for monitoring it is necessary to reduce the cost from the expensive characteristics of multi-monitoring system according to the importance of each data because this system is based on communication of one to several units. We designed the data multi-acquisition system using numbers of micro-controller and the experiment was executed to the actual turn-out system.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.10
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• pp.993-1001
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• 2007

An analysis model has been developed to assess running safety of railway vehicle passing curves. By using ADAMS/Rail, a computer analysis has been conducted by changing various parameters according to the track conditions. Analysis results show as follows: A derailment coefficient of left wheel was increased according to increase of cant at low speed, while it was decreased as increase of cant at high speed. A unload rate of left wheel was also increased according to increase of cant at low speed, while it was decreased as increase of cant at high speed. A wear number of left wheel was increased according to increase of cant at all speed, but only at 35 m/s, it was decreased as increase of cant. A friction coefficient of left wheel was Increased according to increase of cant at all speed, but only at 35 m/s. it was decreased as increase of cant.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.1051-1055
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• 2005

In this paper, the trend of the market demand for the technology of railway cars and the development direction of other country or company were studied by analysing the patent map. The effort for developing the technology is intensified from the middle of 1960s and it seems to be more strengthened especially in the parts of bogie, driving motor/power, window and door. Recently the increasing rate of the number of patent application from Germany and China is noticeable. The results of this paper can be used for making the development plans of competitive technologies and benchmarking of them.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.6
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• pp.841-849
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• 2014

Urban railway with rectifiers is connected by parallel circuits because substations are joined by the power rail. Thus, if an input voltage of a substation is increased, then the voltage of rectifiers is also increased, and which leads to an increase in the peak power of the substation. To solve this problem, this paper proposes a new method reducing the peak power of substations by adjusting the operation number of rectifiers. Its feasibility is exemplified by some simulations performed for Incheon subway Line 1 and GA(Genetic Algorithm) method has been applied to obtain the optimal input. Simulation results show that peak power can significantly be reduced using the method proposed in this paper.