• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.505-508
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• 2000

A coreless printed circuit board(PCB) transformer is employed in a contactless energy transfer circuit that achieves an efficient power conversion at the presence of a considerable airgap between the source and the load side. A half-bridge series resonant converter is selected as the contactless energy transfer circuit in order to minimize the detrimental effects of large leakage inductance small magnetizing inductance and poor coupling coefficient of the coreless PCB transformer. The operation and performance of the proposed contactless power converter are verified on a 7 W experimental circuit that provides an 18V/0.4A output from a 210-370 V input source.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.12
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• pp.2173-2178
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• 2007

Dynamics of plasma sheath was analyzed using simple ion fluid model with poison equation. Incident ion current, energy, potential distribution and space charge density profile were calculated as a function of time. The effects of initial floating sheath on the evolution of biased sheath were compared with ideal matrix sheath. The effects of finite rising time of pulse bias voltage on the ion current and energy was studied. The influence of surface charging on the evolution of sheath was also investigated

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.10
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• pp.69-74
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• 2014

With the increasing interest of energy efficiency, several buildings and factories begin to monitor energy usages with a built-in energy management system. However, the built-in energy monitoring system does not reflect the dynamics of buildings and factories energy usage. To overcome the latter, we deploy several sensors to monitor the dynamics of buildings energy usage patterns. In this paper, we are proposing a framework of a sensor based energy monitoring system. Based on our limited experiments, we can monitor power usages by a person, device and time period. As a result, we can plan a better energy usage and improve energy efficiency by the monitored energy usage profile data.

• Proceedings of the Korean Vacuum Society Conference
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• 1995.02a
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• pp.21-21
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• 1995

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3141-3143
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• 1999

Fuel cell systems offer high energy efficiencies for transportation application. In addition, they can use alcohols and alternative fuels as the fuel, while producing little or no noxious emissions. Fuel cell-powered energy source should be competitive in performance characteristics and in capital and maintenance costs with internal combustion engine systems. From computer simulation program, battery and fuel cell energy output and total power profile, motor power, battery energy output, fuel cell energy output. It simulates the performance of fuelcell/battery powered energy source operation over any user inputted transit route cycle, and provides performance criteria through user specifications for preliminary design consideration.

• Journal of Broadcast Engineering
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• v.19 no.6
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• pp.934-941
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• 2014

In this paper, we present a low profile 2-layered meander built-in monopole antenna for portable RFID reader using FDTD(Finite Difference Time Domain) method. The input impedance, return loss, and VSWR in the frequency domain are calculated by Fourier transforming the time domain results. The double meander 2-layer structure is used to enhance the impedance matching and increase the antenna gain. The measured bandwidth of the antenna is 0.895 GHz ~ 0.930 GHz for a S11 of less than -10dB. The measured peak gain of proposed low profile RFID built-in antenna is 2.3 dBi. And the proposed built-in antenna for portable RFID reader can offers relatively wide-bandwidth and high-gain characteristics, in respectively. Experimental data for the return loss and the gain of the antenna are also presented, and they are relatively in good agreement with the FDTD results. This antenna can be also applied to mobile communication field, energy fields, RFID, and home-network operations, broadcasting, and other low profile mobile systems.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.4 no.4
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• pp.300-306
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• 2011

In this paper, we suggest a usage profiles for electric home appliances. In Korea, it is published the records for total consumption of electricity in a house but the electric home appliance consumption records in a households are not. To build the data, we must collect the usage of every appliances in a house and the information of the household which live in the house. Unfortunately, it is hard to get the data because of the worry about the breach of privacy. In this paper, we make a scenarios on the electricity consumption pattern of a few households type. Based on the conjecture, we make the power consumption profiles for some home appliances. Comparison to the total electric consumption records for a house, we found our scenarios are quite reasonable.

• Journal of the Korean Institute of Telematics and Electronics
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• v.13 no.2
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• pp.23-27
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• 1976

$Si{\cdot}SnO_{2}$ heterojunction was prepared by oxidzing at oxygen atmosphere $SnO_{2-X}$ Which made by Flith evaporation of $SnO_{2}$ powder on III surface of p and n type Si single crystals. The energy band Profile of $Si{\cdot}SnO_{2}$ heterojunction was depicted from its physical properties. This heterojunction was very good rectifying junction, very sensitive in spectral response of Photovoltage at from 400nm to 1200nm, and -10$^{18}$sec of time contant. From above properties, this heterojunction was found ps good high speed photovoltaic device and solar cell.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.1
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• pp.11-17
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• 2011

A major source of durability problems in concrete structures is the corrosion of steel by the damage of passivity layer around steel bars. As chloride ion penetration is major cause of the destruction of passivity layer, evaluation of depth and concentration profile of chloride ion is the essential factor for the service-life estimation of concrete structure. To estimate chloride ion penetration characteristics, this paper on the basis of in-situ experimental data investigated the depth and concentration profile of chloride ion penetration. The core specimens are obtained at air-zone, splash zone, and tidal zone in Wando, Masan, Incheon, Gwangyang, and donghae harbors. Colorimentric method measured the chloride ion penetration depth and ASTM C 114 evaluated the concentration profile of chloride ion. Based on experimental data, the influence of harbor location and exposure condition on chloride ion penetration is evaluated.

• Journal of the Korean Society of Industry Convergence
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• v.15 no.3
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• pp.65-69
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• 2012

Since 2010, enhancement of the building energy efficiency and certification system and public office building should have been acquiring the first grade of Building Energy Efficiency. The Building Energy Efficiency Rating evaluation tool and Dynamic Analysis Energy simulation program for Building Energy Efficiency are widely used. The suitability to those programs have been discussed as a variety of programs have been used accordingly. In this study, evaluated the characteristic of Building Energy Efficiency Rating tool(ECO2) of the business building. At a result, the variables on the Weather Data, building Profile and building Load property in hourly between those Building Energy Efficiency evaluation tools have different.