Jong-Pil Lee

Learn More
Thick polycrystalline pure PbTiO3 films with nano size grains were synthesized for the first time by aerosol deposition. Annealed 7 μm thick films exhibit well-saturated ferroelectric hysteresis loops with a remanent polarization and coercive field of 35 μC/cm(2) and 94 kV/cm, respectively. A large-signal effective d33,eff value of >60 pm/V is achieved at(More)
Spinel structured highly dense NiMn2O4-based (NMO) negative temperature coefficient (NTC) thermistor thick films were fabricated by aerosol-deposition at room temperature. To enhance the thermistor B constant, which represents the temperature sensitivity of the NMO thermistor material, Co and Co-Fe doping was applied. In the case of single element doping of(More)
Diagnosis techniques based on the dissolved gas analysis (DGA) have been developed to detect incipient faults in power transformer. There are various methods based on DGA such as IEC, Roger, Dornenburg, and etc. However, these methods have been applied on the different problems with different standards. Also, it is difficult to achieve the diagnosis with(More)
The paper proposes a new topology for photovoltaic DC/DC converter with high efficiency under wide input voltage range is proposed. Photovoltaic DC/DC is a very crucial part of power conditioning system (PCS). Considering that output characteristic of photovoltaic cell has wide voltage range, depending on the operating conditions of photovoltaic cell, the(More)