• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.3
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• pp.213-220
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• 2008

In this paper, the regenerative inverter system with voltage drop compensation mode is proposed. When the main rectifier is broken, the DC traction can not be supplied the power from the utility. Actually, the reserve rectifier is mounted in the substation to prevent this accident. In this paper, the voltage drop compensation mode is added to the regenerative inverter system in order to substitute the reserve rectifier. The proposed regenerative inverter system returns the regenerative energy from the DC line voltage to the utility. In addition, the inverter can be compensate the harmonics caused by the power conversion devices used in the DC traction system. We demonstrated the effectiveness of the proposed control algorithm by using computer simulation.

• Journal of Drive and Control
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• v.9 no.1
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• pp.1-9
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• 2012

Nowadays, various researches about eco-friendly vehicles such as hybrid electric vehicle, fuel cell vehicle and electric vehicle have been actively carried out. Since most of these green cars have electric motors, the regenerative energy technology can be used to improve the fuel economy and the energy efficiency of vehicles. The regenerative brake is an energy recovery mechanism which slows a vehicle by converting its kinetic energy into electric energy, which can be either used immediately or stored until needed. This technology plays a significant role in achieving the high energy usage. However, there are some technical problems for controlling the regenerative braking and the electro-hydraulic brake during switching at transient region. In this paper, the performance simulator for fuel-cell vehicle is developed and transient response characteristics of the regenerative braking system are analyzed in the various driving situations. And the hardware-in-the-loop simulation of electro-hydraulic brake is performed to validate the transient characteristics of the regenerative braking system for fuel-cell electric vehicle.

• The Journal of KAIRB
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• v.6 no.1
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• pp.1-4
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• 2024

The strengthening of Institutional Review Board (IRB) and Human Research Protection Program (HRPP) for clinical research on advanced regenerative medicine reflecting the 3 Principles of the Belmont Report (Respect, Beneficence, Justice) is very important. The research institution IRB should naturally be in charge of managing the clinical research process. And it is crucial to reinforce HRPP for the protection of research subjects in institutions conducting advanced regeneration clinical research. So, it is needed to establish a Protection System for Advanced Regenerative Medical Research Subjects composed of clinical research management communication system for advanced regenerative medicine between KAIRB (Korean Association of IRB) of research institutes and National Management Agency for Advanced Regenerative Medical Research. In advanced regenerative medicine clinical research to verify safety and efficacy of the investigational drugs to the subjects with rare and incurable diseases rather than to treat the patients, it is hoped that a management system that guarantees the scientific characteristics of research and the rights of research subjects would be well organized and operated.

• Journal of Mechanical Science and Technology
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• v.15 no.11
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• pp.1490-1498
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• 2001

In this paper, a regenerative braking algorithm is presented and performance of a hybrid electric vehicle (HEV) is investigated. The regenerative braking algorithm calculates the available regenera tive braking torque by considering the motor characteristics, the battery SOC and the CVT speed ratio. When the regenerative braking and the friction braking are applied simultaneously, the friction braking torque corresponding to the regenerative braking should be reduced by decreasing the hydraulic pressure at the front wheel. To implement the regenerative braking algorithm, a hydraulic braking module is designed. In addition, the HEV powertrain models including the internal combustion engine, electric motor, battery, CVT and the regenerative braking system are obtained using AMESim, and the regenerative braking performance is investigated by the simulation. Simulation results show that the proposed regenerative braking algorithm contributes to increasing the battery SOC which results in the improved fuel economy. To verify the regenerative braking algorithm, an experimental study is performed. It is found from the experimental results that the regenerative braking hydraulic module developed in this study generates the desired front wheel hydraulic pressure specified by the regenerative braking control algorithm.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.6
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• pp.635-641
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• 2016

Regenerative braking performance of an electrically powered vehicle is closely related to driving distance per battery charge. An electric vehicle uses appropriate amounts of mechanical braking force and electromagnetic regenerative braking force to recover energy and increase driving efficiency. In particular, when it drives on a downhill road, energy recovery rate is maximized through regenerative braking during coasting based on the mass inertia of the vehicle. Since an electric two-wheeled vehicle covered in this paper is lighter than an electric four-wheeled vehicle, the improvement of its driving distance per battery charge through regenerative braking is different from an electric four-wheeled vehicle. This study compared the driving characteristics of an electric two-wheeled vehicle based on regenerative braking. Two driving test modes were simulated with a chassis dynamometer system. By analyzing the measurement of a chassis dynamometer, the driving characteristics of a two-wheel electric vehicle, such as driving efficiency, were analyzed. In addition, test results were reviewed to draw the limitations of conventional test methods for regenerative braking performance of an electric two-wheel vehicle.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1505-1510
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• 2007

In this paper, the power simulation is used for the prediction of regenerative energy and examination of install location of regenerative inverter for DC railway system. The power simulation was composed to train performance simulation(TPS) and power flow simulation. We performed the power simulation for Seoul subway line 5 and 7, calculation of regenerative energy and examination of substations where regenerative inverter is installed.

• Journal of the Korean Society for Railway
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• v.12 no.2
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• pp.254-259
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• 2009

DC transit system has been adopted in the metropolitan area, Korea since 1974. Electric multiple (EMU) in this system always reiterates that acceleration and retardation. When EMU decelerates using electric breaking, regenerative power occurs. Regenerative power can be consumed in vicinity EMU on the same line or in resistor. If DC transit system has inverter for reusing regenerative power, Energy efficiency in DC transit system and the replacement cycle of brake shoe in EMU will be increased and dust due to mechanical braking decreased. This paper present the developed inverter for regenerative power and its test equipment. Test for developed inverter is performed at test equipment and is divided into three items, which are regeneration mode, active filter mode, and system link test.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.12
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• pp.2392-2396
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• 2011

This paper deals with the power integration of large urban railway systems to improve regenerative energy utilization. Current regenerative energy utilization is low because there is no special plan for using this energy. If the railway system is integrated with other railway systems, the efficiency is expected to be improved. Through the case studies, to find the realistic effect of integrated operation, real system for the Seoul Metro lines, especially line 5 and 7, had been applied.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.676-681
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• 2005

The regenerative braked cars are being introduced in DC electric railway for energy saving. There has been a recent tendency for DC traction substation with regenerative inverter to increase in number. This is strongly related to the desire for effective utilization of electric power regenerated by DC electric cars and to the aim ensuring stable operation of regenerative braking system. The regenerative inverters DC power feed back from a generative car into AC power at a substation and supplies it to distribution lines. This paper suggest the result of characteristic analysis and capacity simulation. economical analysis in the regenerative inverter system.

• Clinical and Experimental Otorhinolaryngology
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• v.11 no.4
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• pp.224-232
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• 2018

Objectives. Spiral ganglion neurons (SGNs) include potential endogenous progenitor populations for the regeneration of the peripheral auditory system. However, whether these populations are present in adult mice is largely unknown. We examined the presence and characteristics of SGN-neural stem cells (NSCs) in mice as a function of age. Methods. The expression of Nestin and Ki67 was examined in sequentially dissected cochlear modiolar tissues from mice of different ages (from postnatal day to 24 weeks) and the sphere-forming populations from the SGNs were isolated and differentiated into different cell types. Results. There were significant decreases in Nestin and Ki67 double-positive mitotic progenitor cells in vivo with increasing mouse age. The SGNs formed spheres exhibiting self-renewing activity and multipotent capacity, which were seen in NSCs and were capable of differentiating into neuron and glial cell types. The SGN spheres derived from mice at an early age (postnatal day or 2 weeks) contained more mitotic stem cells than those from mice at a late age. Conclusion. Our findings showed the presence of self-renewing and proliferative subtypes of SGN-NSCs which might serve as a promising source for the regeneration of auditory neurons even in adult mice.