• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.347-349
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• 2007

Charge equalization scheme for HEV lithium-ion battery system is proposed in this paper, where all the primary windings with in parallel bi-directional switches are coupled in series to provide the equalizing energy from the whole battery string to the specific under charged cells. Moreover, to realize minimized size of equalization circuit employing the proposed cell balancing scheme, the optimal power rating design rule according to equalization time and SOC distribution of imbalance is proposed. A prototype of HEV lithium-ion battery system of four cells shows the outstanding charge equalization performance while maintaining greatly reduced size of cell balancing circuit.

• Journal of the Korean Electrochemical Society
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• v.10 no.1
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• pp.31-35
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• 2007

In this review article, we are going to explain the recent development of lithium secondary batteries for a cellular phone. There are three kinds of rechargeable batteries for cellular phones such as nickel-cadmium, nickel-metal hydride, and lithium ion or lithium ion polymer. The lithium secondary battery is one of the most excellent battery in the point of view of energy density. It means very small and light one among same capacity batteries is the lithium secondary battery. The market volume of lithium secondary batteries increases steeply about 15% annually. The trend of R&D is focused on novel cathode materials including $LiFePO_4$, novel anode materials such as lithium titanate, silicon, and tin, elecrolytes, and safety insurance.

• Journal of the Economic Geographical Society of Korea
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• v.25 no.4
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• pp.499-513
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• 2022

This study targets the rechargeable battery industry, which has been rapidly growing recently. The rechargeable battery industry is closely related to the electric vehicle industry. However, other factors also influence it. Currently, rechargeable battery companies show a pattern of restructuring production space by various means. To determine the causes of these production spaces, the factors affecting regional and national scales were thoroughly examined. As a result, the location factors for rechargeable battery-related companies are determined by cooperative relationships with assembled car companies, government policy regulations, and the stability of supply of key materials. And a spatial strategy was implemented to make the most of these circumstances.

• 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.

• Applied Chemistry for Engineering
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• v.20 no.6
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• pp.692-695
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• 2009

Ohmic joule heating electrodes were developed for the electrical heater of the floor of a room. A composite slurry of super pure black and polyvinylidene fluoride with/without the additives of multi-walled carbon nanotube or kindney stone powder was coated as a thin film on the polyethylene terephthalate film. The performances of heating electrodes were evaluated checking specific conductivity, adhesion strength and hardness. The addition of kindney stone powder increases specific resistance and hardness in a small extent. However, the addition of carbon nanotube increases specific conductivity and hardness. The properties of various compositions of ohmic joule heating electrodes were evaluated.

• Korean Journal of Agricultural Science
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• v.45 no.2
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• pp.290-297
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• 2018

Electric drive technology is continually advanced to improve fuel efficiency in the automobile industry. It could improve the fuel efficiency of automobiles by 50% as well as agricultural machinery. The purpose of this study was to measure and analyze the power and current of an electric transplanter based on the planting distances during field operations. The electric transplanter was constructed by mounting the major components of a motor drive system onto a transplanter. The electric transplanter had a 3 kW motor power, and the major components included an inverter, battery, and a battery management system (BMS). The field tests were conducted by travelling at two speeds (300 and 760 mm/s) and by planting at three distances (260, 420 and 630 mm) with the working speed (300 mm/s), during travelling and transplanting. The results showed that the required power increased when the travelling speed was fast. One-way ANOVA for the planting distance and Duncan's multiple range test at a significance level of 0.05 were used to analyze the motor power using statistical analysis software. In addition, the required power increased when the planting distances were short at every working condition. The results of this study would provide useful information for the development an electric transplanter.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.4
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• pp.330-336
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• 2012

FCEV uses 250 ~ 450 V instead of using 12 V battery. High voltage vehicle can cause electric shock, fire and explosion accident. Therefore, it has potential factors that can cause hazard of safety for users. United states of America and Europe legislate regulations such as ECE R100, FMVSS 305 for regulating electrical safety during driving or after collision. The company manufacturing high voltage components must do advanced R&D about Method for improving and confirming the safety of high voltage. We develop the specific hardware components of high voltage wiring system for the power train system and power supply system of Hyundai Motors FCEV. This paper shows test method of insulative performance for securing the electrical safety of high voltage components such as power cable, connectors and buss-bar, and proposals the guide line value for human safety of FCEV according to the test result of our development components.

• Transactions on Electrical and Electronic Materials
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• v.16 no.3
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• pp.135-138
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• 2015

A manganese dioxide (MnO₂) layer and zinc (Zn) layer are used as the cathode and the anode to develop filmtype manganese battery, in which a stack of a MnO₂ layer, gel electrolyte, and Zn layer are sandwiched between two plastic layers. This paper describes the chemical equation of swelling control upon the film-type manganese battery. We examined the reduction of hydrogen formation, by using calcium hydroxide Ca(OH)₂ as an additive in the electrolyte of film-type manganese battery. The phenomena or an effect of reduced hydrogen gas was proven by cyclic voltammogram, X-ray photoelectron spectra (XPS), and volume of hydrogen formation. The amount of H₂ gas generation in the presence of Ca²⁺ ion was reduced from 4.81 to 4.15 cc/g-zinc (14%), and the corrosion of zinc electrode in the electrolyte was strongly inhibited as time passed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.9
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• pp.751-757
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• 2000

The r.f. power effect for Pt doping is investigated on structural and electrochemical properties of amorphous vanadium oxide(V$_2$O$_{5}$) film, grown by direct current (d.c.) magnetron sputtering. Room temperature charge-discharge measurements based on a half-cell with a constant current clearly indicated that the Pt doping could improve the cyclibility of V$_2$O$_{5}$ cathode film. Using glancing angle x-ray diffraction(GXRD) and high-resolution transmission electron microscopy (HRTEM) analysis, we found that the Pt doping with 10W r.f. power induces more random amorphous structure than undoped V$_2$O$_{5}$ film. As the r.f. power of Pt target increases. large amount of Pt atoms incorporates into the amorphous V$_2$O$_{5}$ film and makes $\alpha$-PtO$_2$microcrystalline phase in the amorphous V$_2$O$_{5}$ matrix. These results suggest that the semiconducting $\alpha$-PtO$_2$ microcrystalline phase in amorphous matrix lead to a drastically faded cyclibility of 50W Pt doped V$_2$O$_{5}$ cathode film. Possible explanations are given to describe the Pt doping effect on cyclibillity of the amorphous V$_2$O$_{5}$ cathode film battery. film battery.

• Korea Trade Review
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• v.47 no.5
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• pp.305-319
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• 2022

The Chinese government has been promoting core industries in accordance with the 'Made in China 2025'. As a result of injecting huge subsidies to develop core industries, a great success has been achieved in the electric vehicle and battery industry, however, the semiconductor industry has almost no performance. This study aims to examine whether the subsidy policy of a developing country helps their own domestic firm to overcome the first mover advantage of an advanced country's firm. From the game theoretical analysis, the results have shown that the subsidy policy of the developing country's government creates the profits shifting effect which arises from the developed country's firm to the developing country's firm. When there exists R&D efficiency gap between the two firms, however, most of these profit shifting effects are offset, which implies that the subsidy policy of developing countries is likely to fail.