• Proceedings of the KIPE Conference
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• 2007.11a
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• pp.142-144
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• 2007

This paper proposes problem improvement in existing method about three-phase current reconstruction method and present minimum voltage injection method and Smooth voltage injection method in single current sensor for washing machine motor drive. So, presented wash noise improvement method through ripple reduction in inverter. The simulation and experimental results are given to show the effectiveness of the proposed method for reconstructing the phase currents and reducing the noises.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.08a
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• pp.81-84
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• 2003

Conductive polyaniline(PANI)-camphosulfonic acid (CSA) film applied as a hole injection layer in ITO/PANI/P3HT/LiF/Al device. In the AFM images, electrochemically polymerized PANI-CSA films have the small particles and smooth sufficient for application as hole injection layer. By insertion of PANI-CSA buffer layer, the turn on voltage of ITO/PANI/P3HT/LiF/Al device lowed by 3V, whereas that of ITO/P3HT/LiF/Al device shows 5V.

• Journal of Power Electronics
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• v.18 no.3
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• pp.863-870
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• 2018

The traditional power control theories for the harmonic reduction methods in multilevel inverters are found to be unreliable under unbalanced load conditions. The unreliability in harmonic mitigation is caused by voltage fluctuations, non-linear loads, the use of power switches, etc. In general, the harmonics are reduced by filters. However, such devices are an expensive way to provide a smooth and fast response to secure power systems during dynamic conditions. Hence, the Decoupled Double Synchronous Reference Frame (DDSRF) theory combined with a State Delay Controller (SDC) is proposed to achieve a harmonic reduction in power systems. The DDSRF produces a sinusoidal harmonic that is the opposite of the load harmonic. Then, it injects this harmonic into power systems, which reduces the effect of harmonics. The SDC is used to reduce the delay between the compensation time for power injection and the generation of a reference signal. The proposed technique has been simulated using MATLAB and its reliability has been verified experimentally under unbalanced conditions.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.11
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• pp.1044-1049
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• 2006

We reported on characteristics of the fluorescent OLED fabricated on commercial ITO/glass and BCS grown IZO/glass substrate, respectively. The amorphous IZO anode film grown by box cathode sputtering(BCS) exhibited similar electrical and optical characteristics to commercial ITO anode even though it was deposited at room temperature. In addition, the amorphous IZO anode showed higher workfunction (5.2 eV) than that of the commercial ITO anode (5.0 eV) after ozone treatment for 10 min. Furthermore, fluorescent OLED fabricated on amorphous IZO anode film showed improved current-voltage-luminance characteristics, external quantum efficiency and power efficiency en contrast with fluorescent OLED fabricated on commercial ITO anode film. It was thought that smooth surface and high workfunction of amorphous IZO anode lead to more efficient hole injection by reduction of interface barrier height between anode and organic layers.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.6
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• pp.588-593
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• 2023

The advantage of OTFT technology is that large-area circuits can be manufactured on flexible substrates using a low-cost solution process such as inkjet printing. Compared to silicon-based inorganic semiconductor processes, the process temperature is lower and the process time is shorter, so it can be widely applied to fields that do not require high electron mobility. Materials that have utility as electrode materials include carbon that can be solution-processed, transparent carbon thin films, and metallic nanoparticles, etc. are being studied. Recently, a technology has been developed to facilitate charge injection by coating the surface of the Al electrode with solution-processable titanium oxide (TiOx), which can greatly improve the performance of OTFT. In order to commercialize OTFT technology, an appropriate method is to use a complementary circuit with excellent reliability and stability. For this, insulators and channel semiconductors using organic materials must have stability in the air. In this study, carbon-doped Mo (MoC) thin films were fabricated with different graphite target power densities via unbalanced magnetron sputtering (UBM). The influence of graphite target power density on the structural, surface area, physical, and electrical properties of MoC films was investigated. MoC thin films deposited by the unbalanced magnetron sputtering method exhibited a smooth and uniform surface. However, as the graphite target power density increased, the rms surface roughness of the MoC film increased, and the hardness and elastic modulus of the MoC thin film increased. Additionally, as the graphite target power density increased, the resistivity value of the MoC film increased. In the performance of an organic thin film transistor using a MoC gate electrode, the carrier mobility, threshold voltage, and drain current on/off ratio (I_on/I_off) showed 0.15 cm²/V·s, -5.6 V, and 7.5×10⁴, respectively.