• Proceedings of the KIEE Conference
• /
• 2006.04b
• /
• pp.298-300
• /
• 2006

The changeable set system need to be developed to devoid a traffic congestion for rush hour. We will apply the changeable set system to solve this problems. The cost-effectiveness is reviewed when we apply this system on Korean urban transit system.

• Proceedings of the KIEE Conference
• /
• 2006.10c
• /
• pp.263-265
• /
• 2006

The pure electric braking system need to be developed to stop the electric train to zero speed by electricity. This system has advantages like reduction of weight, maintenance cost, noise, and dust generated by disk friction. Therefore, we will study this system for Korean urban transit system.

• Proceedings of the KSR Conference
• /
• 2006.11b
• /
• pp.1442-1447
• /
• 2006

Recently, According to rapid advancements in railway system and IT have enabled manless operation in urban transit system. Futhermore, development countries have been tried to develop unmaned operation system for reliability, safety, efficiency, and some ones already adopted. In this paper, we define system requirements and functionalities, and establish the system scenarios to handle the various accidents/faults in manless operation environment.

• Proceedings of the KSR Conference
• /
• 2002.10a
• /
• pp.440-445
• /
• 2002

In this paper, traction system for urban transit maglev system is proposed. Using vector control strategy to control magnitude and frequency of output voltage transiently is general. But in case of traction system for railway vehicle, it is impossible that adapt vector control because there is one-pulse mode in a high speed region. So this paper proposes the control strategy using vector control in a low speed region and slip frequency control in a high speed region. And also proposes overmodulation method that makes to change in one-pulse mode softly. The performance of traction system will be verified by simulation results using ACSL.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.17 no.5
• /
• pp.115-126
• /
• 2009

This paper studied on the application of the crashworthiness regulations of Korean Railway Safety Law and Urban Transit Safety Law to the urban Maglev vehicle of KIMM. The Urban Maglev vehicle has to comply with the crashworthiness regulations for urban transit vehicles. The collision load cases have been simulated by using explicit finite element analysis. From the numerical results, the crashworthiness regulations of the Urban Transit Safety Law were completely satisfied, but maximum crash pulse requirement in 25 km/h crash event and no plastic deformation requirement in 10 km/h crash event in the Korean Railway Safety Law were not. If a commercial urban Maglev vehicle is developed in the near future, it is necessary that some soft buffing and energy absorbing devices are adopted in its front end so as to satisfy the crashworthiness regulations of the Korean Railway Safety Law.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.619-627
• /
• 2009

It is very important that reduce the maintenance cost and extend life time of the urban transit EMU through effective maintenance method research. The maintenance cost of the urban transit EMU shares 70%$\sim$80% of it's life cycle cost. It means that the maintenance cost is bigger than the introduction cost of the urban transit EMU. In this study, we were survey and analysis for the reliability centered maintenance of internal and external many industry parts. Finally, we suggested the reliability/availability management System of the Urban Transit EMU' Maintenance.

• Journal of Korean Society of Transportation
• /
• v.24 no.1 s.87
• /
• pp.59-72
• /
• 2006

In spite of continuous implementation of the transportation demand management (TDM), the profuse use of car at the peak-time has caused chronic traffic congestion in the Seoul downtown area. This study makes a comparative analysis on the effectiveness of commuting cost subsidy system for public transit user with other policy instruments such as an increment in fuel tax and park cost. This study not only follows standard guidelines of stated preference methodology to guarantee objectivity, but also uses sample enumeration method and non-Parametric bootstrapping method to secure reliability of empirical results. As a result of empirical studies, the conversion effect of car to public transit is superior to other two Policy instruments. Also. an increment in fuel tax and park cost is income-regressive from the equity aspect in a wage bracket, but commuting cost subsidy system for Public transit user is Income-progressive As a fundamental research on commuting cost subsidy system for public transit user, this study is likely to Provide Policy-makers with quantitative information useful in establishing Public transport Policy to Promote the use of the public transit.

• The Bulletin of The Korean Astronomical Society
• /
• v.35 no.2
• /
• pp.65.2-65.2
• /
• 2010

We present four new transits of the planetary system TrES-3 observed between 2009 May and 2010 June. Among those, the third transit by itself indicates possible evidence for brightness disturbance, which could originate from a starspot or an overlapping double transit. A total of 107 transit times, including our measurements, were used to determine the improved ephemeris with a transit epoch of $2454185.910950\pm0.000073$ HJED (Heliocentric Julian Ephemeris Date) and an orbital period of $1.30618698\pm0.00000016$ d. We analyzed the transit light curves using the JKTEBOP code and adopting the quadratic limb-darkening law. In order to derive the physical properties of the TrES-3 system, the transit parameters are combined with the empirical relations from eclipsing binary stars and stellar evolutionary models, respectively. The stellar mass and radius obtained from a calibration using $T_{eff}$, log $\rho$ and [Fe/H] are in good agreement with those from the isochrone analysis within the uncertainties. We found that the exoplanet TrES-3b has a mass of $1.93\pm0.07\;M_{Jup}$, a radius of $1.30\pm0.04\;R_{Jup}$, a surface gravity of $28.2\pm1.1\;m\;s^{-1}$, a density of $0.82\pm0.06\;\rho_{Jup}$, and an equilibrium temperature of $1641\pm23K$.

• Proceedings of the KIEE Conference
• /
• 2001.07b
• /
• pp.1220-1222
• /
• 2001

We proposed a modularization design technique for implementing software of on-board train control system. We already proved the efficiency of CASE Tool(SCADE) for safety critical software design. The several functions of train are implemented on CASE tool each modules. We divided functions of train into modules based on the modularization design. We used MATLAB for design of on-board train control software. We proved that this technique is more useful for the software design of on-board train control for EMU.

• Proceedings of the KSR Conference
• /
• 2007.11a
• /
• pp.729-733
• /
• 2007

Urban transit is a large scale complex system which combines rolling stocks, power supply, signal communications, tracks & stations. Therefore standardization is very important because it is difficult to find causes when failures or accidents occur. The standardization of urban transit increases safety and economical efficiency, and also gives passengers convenient and comfortable feeling. We, Korea Railroad Research Institute(KRRI), had finished the 1st phase study of urban transit standardization from '95 to '06. And 2nd phase study on rolling stock, information & communication, subway station has been performed from July '07. In this paper, we introduce what we study on urban transits standardization during coming 5 years. We expect our study will contribute to increase the efficiency of urban transit.