• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.685-687
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• 2002

For several decades researches and developments on superconducting magnetic energy storage (SMES) system have been done for efficient electric power management. Korea Electrotechnology Research Institute(KERI) have developed of a 1MJ. 300kVA SMES System for improving power quality in sensitive electric loads. We developed the code for design of a SMES magnet. which could find the parameters of the SMES magnet having minimum amount of superconductors for the same stored energy. and designed the 1MJ SMES magnet by using it. This paper describes the design. fabrication and experimental results for the SMES magnet. cryostat, HTS current lead and power converter.

• ETRI Journal
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• v.34 no.6
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• pp.838-846
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• 2012

This paper proposes a cost-effective hybrid-type power budget extender (PBEx) that can provide a high power budget of over 45 dB in an asymmetric 10-Gb/s Ethernet passive optical network (10/1G-EPON). The hybrid-type 10/1G-EPON PBEx comprises a central office terminal (COT) and remote terminal (RT) module supporting four channels and uses a coarse wavelength division multiplexing (CWDM) technology between the COT and RT for a reduction of fiber cost and efficient access network design. The proposed 10/1G-EPON PBEx can provide over a 40-km reach and 128-way split per CWDM wavelength with no modification of a legacy 10/1G-EPON system and can satisfy the error-free service in $10^{10}$ packet transmission.

• Journal of Magnetics
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• v.18 no.2
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• pp.105-110
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• 2013

The design model and key parameters of the material design for the control of induced magnetic flux at the near-field and efficient power transfer in a modified wireless power transfer (WPT) system with a large air gap of wireless electric vehicles were investigated through analytical simulations for magnetic vector and time-domain transient analysis. Higher saturation magnetic core with low core loss induced a stronger vertical magnetic field by the W-type primary coil in the WPT system with a gap of 20 cm at 20 kHz, which is shown from the vector potentials of the magnetic induction. The transient analysis shows that the higher magnetic fluxes through the pick-up cores lead to a linear increment of the alternating voltage with a sinusoidal waveform in the non-contact energy transfer system.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.2027-2029
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• 1998

We have developed a compact high frequency switch mode converter (HFSMC) power supply with DC 50 kV output voltage and 10 kW output power. Since the inverter circuit uses 25 kHz rescharging scheme, the current is flowing with t kHz. For the efficient output voltage transform performed a simple design process using the transformer principle and the commercial specification. For the DC 50 kV output, we employed 7 pa windings of secondary coils for the series stac connection of the output with full-bridge rectifi In this paper the design detail and the test re the high frequency transformer together with HFSMC power supply are presented.

• Transactions on Electrical and Electronic Materials
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• v.1 no.3
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• pp.1-5
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• 2000

This paper presents a new sort of multilayer piezoelectric ceramic transformer for switching regulation power supplies. This piezoelectric transformer operate in the second thickness resonant vibration mode. Accordingly its resonant frequency is higher than 1 NHz, Because output power is low if input and output part of transformer are consisted of single layer, this research suggests a new method, which is consisted of both input and output part of transformer have 2-layered piezoelectric ceramics, The size of transformer is 20 mm in width and length, and 1.4 mm in thickness, respectively, To design a high efficient switching circuit of the transformer, internal circuit parameters were measured and then weve calculated a parameter of inductor nd capacitor to design a driving circuit, Weve used a MISFET and its driver circuit modified a calp oscillator circuit as the primary switching circuit.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.111-114
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• 2004

Sensor networks are deployed with a limited energy source. Thus, energy efficient design can be challenging. This paper has been studied optimal packet length with energy efficiency for sensor networks. And using Power Management can not improve energy efficiency. Power Management is turning off transceiver when transceiver is idle statue. We show that BCH code for error control can improve energy efficiency better than Convolutional code.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.1024-1029
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• 1998

In this paper, the voltage-fed series compensated inductor type load-resonant high-frequency inverter is originally presented for driving a newly-developed silent discharge ozone generating tube. The effective power regulation scheme of this ozonizer is proposed, which is based on PDM (Pulse Density Modulation) related PWM strategy due to DSP implementation. The effectiveness of this inverter type ozonizer is proved in simulation and experiment.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.945-947
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• 1997

Transmission capacity is becoming higher according to the increase of power demand. But construction of T/L is very difficult due to the securing of ROW and environmental problems. Then in order to consider efficient utilization of T/L, this paper suggests basic design methods of low-loss conductors.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.535-540
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• 2003

Urban transit, which takes an important role of traffic volume, is operated in four different urban communities and constructed in two urban communities. However, the urban transit of each communities has different system in operation and construction. It is not efficient to construct and operate. Furthermore, is difficult to maintain urban transit system. In this paper, the standardization of power supply system for urban transit has been performed to solve above problems.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.196-196
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• 2004