• Journal of Biosystems Engineering
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• v.43 no.2
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• pp.94-102
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• 2018

Purpose: In this study, a maintenance free super-capacitor battery charging system based on the photovoltaic module, to be used in agricultural electric carriers, was developed and its charging characteristics were studied in detail. Methods: At first, the electric carrier system configuration is introduced and the electric control components are presented. The super-capacitor batteries and photovoltaic module used in the experiment are specified. Next, the developed charging system consisting of a constant current / constant voltage Buck converter as the charging device and a super-capacitor cell as a balancing device are initiated. The proposed circuit design, a developed PCB layout of each device and a proportional control to check the current and voltage during the charging process are outlined. An experiment was carried out using a developed prototype to clarify the effectiveness of the proposed system. A power analyzer was used to measure the current and voltage during charging to evaluate the efficiency of the energy storage device. Finally, the conclusions of this research are presented. Results: The experimental results show that the proposed system successfully controls the charging current and balances the battery voltage. The maximum voltage of the super-capacitor battery obtained by using the proposed battery charger is 16.2 V, and the maximum charging current is 20 A. It was found that the charging time was less than an hour through the duty ratio of 95% or more. Conclusions: The developed battery charging system was successfully implemented on the agricultural electric carriers.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.6
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• pp.34-42
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• 2011

With the progress of USN technology, fields to which wireless sensor node is applicable are increased under a condition that it holds a lot of problems to solve for betterment. One of the problems which acts as an obstacle to USN industry diffusion is the wireless sensor node battery exchange to their individual life cycle. Exchanging the battery of so many sensor nodes one by one requires a great deal of times and costs. Such problem is against the convenience supply -aim by applying USN technology. In this paper, using RF wireless power transmission system that power transmission / harvesting module from a distance of 5 m and the power of 10 dBm with a current of 1 mA or more for Sensor Nodes in lithium-polymer battery charging system tested and verified.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.3
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• pp.13-23
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• 2022

Demand and interest in electric vehicles are increasing rapidly due to environmental issues. Improving the performance of electric vehicles requires the development of automotive batteries and battery joining technologies. Aluminum alloys are the most widely used metals in the electric vehicle industry, and aluminum bonding is used in all processes comprising automotive batteries. Therefore, in this paper, based on the characteristics of aluminum and aluminum alloys and knowledge of various aluminum joining technologies, the main and the next generation bonding technologies used in automotive battery are reviewed. It also explains the structure of automotive secondary battery cells and the integration order of 'cell-module-pack' where joining is used in the process, also various environmental conditions that must be considered when joining.

• Journal of Environmental Health Sciences
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• v.17 no.1
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• pp.95-103
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• 1991

For the purpose of estimating the working environment and the relationship between the airborne lead concentration and the ZPP level in the whole blood of the workers, the airborne lead concentrations and the ZPP level were measured at the 26 plants which deal with lead, from October 5 to November 5 in 1988. Analysis of the airborne lead concentration was performed by NIOSH Method 7082, and the ZPP level was measured by a hematofluorometer. The following results are concluded. 1. The average airborne lead concentration of the lead battery manufactures is 0.025mg/m$^{3}$ and that of the secondary lead smelters is 0.023mg/m$^{3}$. There were no significant differences between industry (p>0.1) 2. At the lead battery manufacture, the process of lead powder production showed the highest concentration of 0.034mg/m$^{3}$ but there were no significant differences among the processes (p>0.1). At the secondary lead smelter, the process of dismantling waste batteries showed the highest concentration 0.141mg/m$^{3}$, and there were very significant differences among the processes (p<0.005). 3. The ZPP level in the whole blood showed significant differences between industry (p<0.10). The average ZPP level of the lead battery manufactures is 133.0 + 106.3 $\mu$g/100ml and that of the secondary lead smelters is 149.6 + 110.9 $\mu$g/100ml. 4. The correlation coefficients between the airborne lead concantration and ZPP level were 0. 426 (p<0.001) for the lead battery manufactures and 0.484 (p<0.001) for the secondary lead smelters. The correlation coefficients between the work duration (in months) and the ZPP level were 0.238 (p<0.001) for the lead battery mannfactures and 0.075 (p>0.10) for the secondary lead smelters. 5. The linear regression equation, with the airborne lead concentration as an independent variable and the ZPP level as a dependent variable, is Y=96.84+1300.34X (r=0.448, p<0.001) for the 26 plants which deal with lead. The linear regression equation, with the work duration(in months) as an independent variable and the ZPP level as a dependent variable, is Y=127.28 +0.49X (r=0.162, p<0.05). 6. The correlation coefficients between the amount of inhaled lead and ZPP level were 0.349 (p < 0.001) for the lead battery manufactures and 0.318(p<0.001) for the secondary lead smeltes. The linear regression equation for the 26 plants surveyed, with the amount of inhaled lead as an independent variable and ZPP level as a dependent variable, is Y=123.63+18.82X (r=0. 335, p<0.001).

• Journal of KIISE
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• v.44 no.6
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• pp.601-606
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• 2017

Recently, we have frequently encountered flying drones with the growth of drone industry. However, it is difficult for a driver to stabilize the motor speed of drones, since the voltage of a Lithium polymer battery used in drones may suddenly drop or rise when its power is exhausted. The instability of the motor speed precludes the drone from maintaining a flight altitude, so that the fuselage of a drone performs ascending and descending repeatedly. For solving this problem, existing techniques either add a compensator considering voltage drop of battery or change the control model. Since these techniques use hardware-implemented modules or depend on motor type and experimental results, there is a problem that new suitable modules should be implemented in accordance with the used motor of the fuselage. For solving this problem, in this paper, we implement a motor speed controller in the firmware of drones by considering voltage drop of battery to enhance drone flight stability.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.131-134
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• 2001

The three-dimensional precision measurement technology for industry product of middle and/or large scale has been developed. Theodolite measurement system which is one of the technology is widely used in aerospace industry. This paper describes measurement method and results for spacecraft structure test model by using the measurement system. And structural stability for STM is desribed through the comparison between design values and measured values.

• Journal of the Korean Electrochemical Society
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• v.10 no.3
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• pp.184-189
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• 2007

The importance of secondary battery industry is getting excited according to the development of battery industry as a high efficiency energy supplier of electronic machine of mobile information such as mobile phone, lap-top computer, PDA. It is rasing the interest about security of safety and high efficiency of cathode material for main part of secondary lithium battery. The cathode material which has been used like $LiCoO_2,\;LiMn_2O_4,\;LiNi_xCo_yMn_zO_2,\;LiNi_xCo_yM_zO_2$ (M=Al, Zr, Mg etc.,) the most typical material is $LiCoO_2$. But it is studying the development of substitute such as efficiency amelioration of $LiCoO_2$, thetiary element, olivine element because of the capacity of $LiCoO_2$, the matter of security; especially the betterment of efficiency, security research of safety has been actively processed in domestic and overseas about surface coating treatment of active cathode which is using oxide ($M_xO_3$). This study analyses side effect of battery according to increase of surface treatment, formation of precipitation for reagent condensation, non-reagent residue of oxide ($M_xO_3$) which is remains during the surface treatment of $LiCoO_2$; conducts study of new process, the consideration of the electrochemical property to improve oxide solution of mixing rate, mixture of surface treatment, dryness, calcinations conditionetc.

• Journal of the Korean Society of Industry Convergence
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• v.1 no.1
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• pp.31-41
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• 1998

Fuel conservation and environmental pollution control are the principal motivating factors that are urging at present widespread research and development activities for electric hybrid vehicles throughout the world. The paper describes different possible energy storage devices, such as battery, flywheel and ultra capacitor, and power sources, such as gasoline engine, diesel engine, gas turbine and fuel cell for next generation hybrid electric vehicle. The technology trend and comparison in energy storage and power devices indicate that battery and gasoline engine, respectively will remain the most viable devices for hybrid vehicle at least in the near future.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.7
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• pp.992-998
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• 2015

The ESS is composed of Battery Package, PCS(Power Conditioning System) Package, BCU(BESS Control Unit). In Jeju smart grid test-bed, we have developed a business model by ESS power system, renewable energy, transportation, such as customers, and have demonstrated above things. We have analyzed the EMS(Energy Management System) model of KPX where manages supply and demand of domestic electrical power system. We modified and launched EMS for microgrid but the cost was expensive and the system was large size. For releasing this system from industry as a whole, it is imperative to develop PMS(Power Management System) for microgrid. However, the cost of EMS for microgrid is expensive, some systems because it is a large development of the all of the first fruits in urgent PMS(Power Management System) for microgrid to be used in industry in general. Therefore, in this paper, we propose the ESS model considering the power systems characteristics and extensibility in korea. and also we propose the PMS to manage the ESS systems.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.2_1
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• pp.139-147
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• 2020

In order to satisfy the voltage levels of the low voltage battery side and high voltage DC bus, a high voltage gain with bidirectional operation is required. In this system, the cost effectiveness of the design is a critical factor; therefore, the system should be designed using a small number of components. This paper propose a novel bidirectional converter composed with a quasi-sepic and switched-indictor network. The proposed converter consists a small number of components with a high voltage gain ratio. Detailed analysis are made with respect to the operating mode, number of components, voltage and current ripple and efficiency. To verify performance of the proposed converter, simulation was performed is this paper. The simulation results are shown to verify the feasibility and performance of the proposed bidirectional converter.