• Transactions on Electrical and Electronic Materials
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• v.9 no.6
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• pp.260-264
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• 2008

The operational characteristics of superconducting amplifier using vortex flux flow were analyzed from an equivalent circuit in which its current-voltage characteristics for the vortex motion in YBCO microbridge were reflected. For the analysis of operation as an amplifier, dc bias operational point for the superconducting amplifier is determined and then ac operational characteristics for the designed superconducting amplifier were investigated. The variation of transresistance, which describes the operational characteristics of superconducting amplifier, was estimated with respect to conditions of dc bias. The current and the voltage gains, which can be derived from the circuit for small signal analysis, were calculated at each operational point and compared with the results obtained from the numerical analysis for the small signal circuit. From our paper, the characteristics of amplification for superconducting flux flow transistor (SFFT) could be confirmed. The development of the superconducting amplifier applicable to various devices is expected.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1129-1133
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• 2002

This paper presents an electronic ballast using a novel multiplex modulation method for the metal halide lamp. The proposed modulation method, which has a modulating signal of swept multiplex frequency, can eliminate the acoustic resonance more effectively than the conventional modulation method, which has a modulating signal of constant frequency. For the purpose of future application specific integrated circuits (ASIC), the controller of the proposed ballast has been designed only with erasable programmable logic devices (EPLDs), but without a microprocessor. In this paper, detailed proposed modulation schemes are described and experimental results on the proto-type 150W metal halide lamp ballast with the proposed modulation method are discussed.

• Journal of Information Display
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• v.9 no.3
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• pp.1-7
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• 2008

With the aim of creating a high-quality display system with value-added functions, we designed a current mode multiplexer for LTPS TFT devices. The multiplexers had less than 1 volt logic swing, and speed improvement was evident compared with that of conventional CMOS architecture. We refined the multiplexer to achieve a more stable current steering operation. By using the versatility of the multiplexer, a new NAND/AND and NOR/OR logic gates were designed through the simple modification of signal connections. Two micron LTPS TFT parameters were used during the HSPICE simulation of the circuits.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.36-39
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• 2003

Conducting polymers are finding increasing number of applications in various electronic devices such as chemical sensors, electrochromic display, light emitting diodes, etc. Polyaniline(PANI) ranks among highly prospective conduction polymers. PANI was first synthesis in 1862[1] and has been extensively studied as a conducting polymer since the 1980s[2]. The side range of electrical, electrochemical and optical properties coupled with good environmental stability makes PANI potentially attractive for application as an electronic material. (omitted)

• Journal of Magnetics
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• v.7 no.3
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• pp.98-100
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• 2002

Tunnel magnetoresistive devices using an individual multi-walled carbon nanotube were fabricated and their low-temperature electrical transport propertiers were investigated. With the ferromagnetic Co electrodes, the multi-walled carbon nanotube exhibited hysteretic magnetoresistance curve at low temperatures. Depending on the temperature and the bias current, the magnetoresistance ratio can be as high as 16% at the temperature of 2.2 K. Such high magnetoresistance ratio indicates a long diffusion length of the multi-walled carbon nanotube.

• Transactions on Electrical and Electronic Materials
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• v.7 no.5
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• pp.247-251
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• 2006

The traction DC feeder cable is one of the key devices for the safety operation of subway system, but for low voltage DC feeder cable (<3000 V) for subway, little attention has been paid by investigators on its online monitoring technology. With an introduction of cable laying and operation environment for the cable, this paper investigated the on-line monitoring technology of 1500 V DC feeder cable of subway. Firstly, in the text, the fault model of 1500 V DC cable was proposed based on the analysis of the fault type of the DC feeder cable, and then put forward synthetically on-line monitoring discharge signal and DC leakage current signal to assess DC feeder cable insulating state. The results of laboratory experiment prove that the proposed methods are feasible and can be implemented on-line monitor on DC feeder cable of subway.

• Transactions on Electrical and Electronic Materials
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• v.13 no.4
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• pp.188-191
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• 2012

This paper introduces a new method regarding deuterium incorporation in the gate dielectric including deuterium implantation and post-annealing at the back-end-of-the process line. The control device and the deuterium furnace-annealed device were also prepared for comparison with the implanted device. It was observed that deuterium implantation at a light dose of $1{\times}10^{12}-1{\times}10^{14}/cm^2$ at 30 keV reduced hot-carrier injection (HCI) degradation and negative bias temperature instability (NBTI) within our device structure due to the reduction in oxide charge and interface trap. Deuterium implantation provides a possible solution to enhance the bulk and interface reliabilities of the gate oxide under the electrical stress.

• Transactions on Electrical and Electronic Materials
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• v.17 no.3
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• pp.143-145
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• 2016

In order to find suitable source and drain (S/D) electrodes for amorphous InGaZnO thin film transistors (a-IGZO TFTs), the specific contact resistance of interface between the channel layers and various S/D electrodes, such as Ti/Au, a-IZO and multilayer of a-IGZO/Ag/a-IGZO, was investigated using the transmission line model. The a-IGZO TFTs with a-IGZO/Ag/a-IGZO of S/D electrodes had good performance and low contact resistance due to the homo-junction with channel layer. The stability was measured with different electrodes by a positive bias stress test. The result shows the a-IGZO TFTs with a-IGZO/Ag/a-IGZO electrodes were more stable than other devices.

• Applied Science and Convergence Technology
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• v.24 no.5
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• pp.167-171
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• 2015

Quantum-confined nanostructures open up additional perspectives in engineering materials with different electronic and optical properties. We have fabricated unique cation-exchanged CdS and CdS/CdSe quantum dots and measured their first four exciton transitions. We demonstrate that the relationship between electronic transitions and charge-carrier distributions is generalized for a broad range of core-shell nanostructures. These nanostructures can be used to further improve the performance in the fields of bio-imaging, light-emitting devices, photovoltaics, and quantum computing.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.12
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• pp.1002-1009
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• 2011

The light extraction efficiency of top-emitting organic light-emitting diode (OLED) was improved by insertion of corrugation patterns between indium tin oxide and organic layers. The corrugation patterns was fabricated by nanosphere lithography, which could form a self-assembled particle monolayer over a large area. The electrical and optical properties for the OLED devices fabricated by vacuum evaporation, were investigated. We have demonstrated the enhancement of the power efficiency of corrugated OLED. As a result, the power efficiency of the corrugated OLED was found to be more than 42%.