• Transactions of the KSME C: Technology and Education
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• v.3 no.3
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• pp.165-173
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• 2015

This paper presents numerical results of static structural stability analysis in development of a vertical transfer device of a PRT(Personal Rapid Transit) vehicle. The vertical transfer of a fully occupied vehicle operating on a road network is the first attempt, which is expected to contribute to overcome the limitations of conventional 2-dimensional operation mode. In particular, the vertical transfer apparatus designed based on vertical circulating conveyors is capable of continuous transfer without time delay so that it enables to accommodate a high traffic density. This system has been frequently used in a logistics field; however, it is essential to assess a structural integrity because an external force by a vehicle weight is exerted on the conveyors in the form of a concentrated load unlike a conventional logistic transport. In this study, prior to the production process, the structural performance of the pilot design in an early stage is numerically evaluated using the commercial finite element method (FEM) solver (i.e., $Ansys^{(R)}$).

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.4
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• pp.100-115
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• 2020

Recently, with the development of various sensors and communication technologies, the market for wearable devices capable of recording physical activity in connection with a smartphone is expanding. The purpose of this study is to analyze physical activity for each transportation modes in order to utilize wearable devices in the field of transportation. This study consists of three steps: data collection, basic statistical analysis, and physical activity analysis. Four adult males and females were recruited as investigators, and physical activity and route information were collected through Fitbit, a commercial wearable device. From the collected physical activity information, a percentage of heart rate reserve (%HRR) using a heart rate was derived and used for analysis. As a results, it was found that there is a statistically significant difference in heart rate for each transportation mode, and physical activity intensity is the highest when walking. In addition, the results of physical activity analysis for the case of using different routes for the same OD were presented. The results presented in this study are expected to be used as basic data for preparing public transportation activation policies and providing customized services for the future.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2503-2516
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• 2011

According to Railway Safety Act, Korea Transportation Safety Authority (KOTSA) has been entrusted with 'Integrated Railroad Safety Audit (IRSA) and has implemented the safety audit to the railroad operation agencies such as Korea Railroad (KORAIL) and the railroad facility management organization such as the Korea Rail Network Authority (KR Network). The target of IRSA is to establish the effective rail safety management system and to raise the safety level of the railroad operation and facility agencies by checking synthetically their performance of safety duties with sincerity according to the Railway Safety Act. Even though newly introduced IRSA is conducted smoothly, it is necessary to study the methodology and criteria of the state's safety audit system. The purpose of this paper is to improve the efficiency of IRSA by the comparative research between IRSA and other similar safety audit system and to establish the consecutive improvement concept of IRSA. Second purpose is to confirm the effectiveness of IRSA by the analysis of the relationship between audit results and the safety level of the rail operation agencies.

• Proceedings of the KIEE Conference
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• 2008.04c
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• pp.178-180
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• 2008

With the increase in population, the area of human activities has expanded, resulting in the dramatic increase in the need for transportation system. Tilting trains are currently in operation in 13 countries around the world. TTX(Tilting Train express) has been developed by KRRI(Korea Railroad Research Institute) for last 6 years to satisfy the need. This train developed in this Project is designed for a design speed of 200km/h and a maximum operating speed of 180km/h. We developed a measurement system for on-line test. the measurement console desk is mounted on T car, which is designed as the DAQ system train. It is comprehensive of the industrial computers, LCD monitors, communication cards and the communication channel measurement system. Using this system, SIV performance evaluation was conducted.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.7
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• pp.694-701
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• 2013

The gear-reduction units of Korean high-speed trains consist of a motor reduction unit, an axle gear box reduction unit, and a tripod joint shaft. A reduction gear unit is a gearbox used to reduce the rotational speed of the input shaft to a slower rotational speed on the output shaft. This reduction in output speed helps to increase torque. Defective reduction gear units in high-speed trains are caused by damage to the gear or by gear fatigue. To diagnose potential problems, it is important to know the vibration characteristics of the reduction gear units. In this study, we analyzed the vibration characteristics of reduction gears under various conditions. The test setup included a full-scale test rig to evaluate reduction gear under both normal and extreme operating conditions.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1181-1182
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• 2007

Light Rail Transit (LRT) System is an urban transit system which has approximately an intermediate transportation capacity between conventional subway and bus ($5,000{\sim}25,000$ persons per hour and per direction). It is a high-tech system which operational capacity, punctuality and mobility are remarkably improved. There are some types of LRT systems such as monorail, tramway, AGT(Automated Guideway Transit), and so on. The LRT systems have been applied and being operated in about a hundred lines around the world and many projects that apply the LRT systems in Korea are being proceeded and scheduled. For the efficient management, economical construction, and safe operation of various LRT systems, the establishment of national standard is necessary such as vehicle standardized specification, vehicle performance test standard, vehicle safety standard, construction guide, operation regulation, etc. of LRT systems. This paper presents the standard specification of electrical equipment of linear induction motor type light rail vehicle, that is LIM AGT(AGT system propelled with linear induction motor) vehicle. The LIM AGT system has been applied in Japan subway and ART(Advanced Rapid Transit) system of Canada and Yongin LRT is currently under construction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.755-761
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• 2017

In railways powered by AC power, the main circuit breaker (MCB) is used for supplying the electric power to the catenary of the vehicle. Generally, the main circuit breaker is located between the pantograph and the main transformer, and the phase of the power applied to the vehicle changes according to the operation timing of the main circuit breaker. The operation of the main circuit breaker should be actively controlled according to the phase of the power source, since the phase of the power causes unintended transient states in the vehicle's electrical system in the form of an inrush current and surge voltage. However, the MCB has a delay time when it operates which is not constant. Therefore, an intelligent controller is needed to predict the operation delay time and control the opening and closing of the MCB.

• Journal of the Society of Disaster Information
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• v.7 no.4
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• pp.259-265
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• 2011

After the commercial opening of the KTX in 2005, the high speed railroad has been rapidly emerged as the major transportation means due to its high energy efficiency. Recently, the government has announced its plan to build the future transportation system around the high speed railroad. Based on this policy, the existing lines as well as the lines under construction or design are planning to increase design speed. In this paper, the suitability of the mid-span PSC girder bridges for the high speed railroad is evaluated via dynamic analysis. IT, Precom, and WPC girder bridges are considered for the purpose of this study and, for comparison, the identical modeling method and the analysis technique are utilized. The performance indices used for dynamic performance evaluation are the natural frequency, the vertical displacement, the end axial displacement, track irregularity, etc. The KTX train is utilized as a dynamic load, and the dynamic analysis is performed up to the train speed of 420km/hr with the increment of 10km/hr.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2911-2916
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• 2015

The elevated railway station, above which a train is passing, is vulnerable to noise and vibration compared to other station types. To better identify the vibration characteristics of the elevated railway station, the transferred vibration from approach bridges should be analyzed. In this paper, through experiments and simulations, the transfer characteristics of the vibration from approach bridges is analyzed. The study structure is Geomgok station and the anaylses are conducted using ABAQUS three dimensional numerical model. To identify the change in the transfer characteristics for various bearing types, the analyses are performed considering mechanical properties of bearing for railway bridges. The measurement is performed using the accelerometers attached to the approach bridges and the station structure along the passing path of trains.

• Journal of the Korean Society for Railway
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• v.13 no.3
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• pp.339-348
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• 2010

The government continues to make efforts to improve effectiveness, integration and connectivity of public transportation systems. But there have been only a few studies about it. This paper addresses the quality evaluation of pedestrian facility service in transfer stations at urban railroad. LOS (Level Of Service) model of urban railroad by facility based on the body ellipse and density recalculated considering the recent Korean body standard and the suggested Pedestrian Moving Equivalent (PME) and Pedestrian Waiting Equivalent (PWE). For LOS model for the ticket booths and ticket vending machines, queuing theory has been applied to determine LOS of Pedestrians. And the importance weights among the pedestrian facilities is obtained by applying AHP analysis. Lastly, this paper shows and discusses the evaluation results of overall LOS of pedestrian facilities of five urban railroad transfer stations in Seoul.