김기홍 교수

This paper proposes a low-voltage ride-through scheme for the permanent magnet synchronous generator (PMSG) wind power system at the grid voltage sag. The dc-link voltage is controlled by the generator-side converter instead of the grid-side converter (GSC). Considering the nonlinear relationship between the generator speed ω <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</sub> and the dc-link voltage V <sub xmlns:mml="http://www.w3.org/1998/Math

A new compatibilizer, polythiophene-graft-poly(methyl methacrylate) (PMMA), for poly(styrene-co-acrylonitrile) (SAN)/multiwalled carbon nanotube (MWCNT) composite is synthesized. Fluorescence emission spectra and Raman spectra indicate that the polythiophene part of the compatibilizer strongly interacts with the surface of MWCNT, while differential scanning calorimeter (DSC) thermograms show that the PMMA graft of the compatibilizer is miscible with the SAN matrix. The use of new compatibilizer

The ammonium perchlorate composite propellant is a common choice for solid rocket propulsion. The externally heated rocket via fires, for instance, can cause the energetic substance to ignite, and this may lead to a thermal runaway event or a slow cook-off phenomenon marked by a severe explosion. To develop preventive measures to reduce the possibility of such accidents in propulsion systems, we investigate the ignition and initiation characteristics of ammonium-perchlorate-based propellants and

This study conducted the Korean version of Mini-Mental State Examination (MMSE-K) to women aged 65 or older residing in Gangwon-do Province and screened those who were suspicious to have mild dementia for receiving 23 points or lower in it. For eight weeks, this author tried to verify the effects of whole body vibration exercise intervention on electroencephalogram (EEG) activation and cognitive function in women with senile dementia. According to the results, both EEG activation and cognitive f

This paper proposes a robust control strategy of the PMSG wind power system for the grid voltage sag. The DC-link voltage control is achieved by the generatorside converter instead of the grid-side converter. Considering the nonlinear relationship between the generator speed (ω <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</sub> ) and DC-link voltage (v <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink

The microstructural and electrical-property changes of undoped and 5.4% nitrogen-doped Ge 2 Sb 2 Te 5 were investigated. The transition temperature of sheet resistance increased owing to nitrogen doping, which corresponded well with the observed phase-change states. The lattice parameters of the undoped and nitrogen-doped Ge 2 Sb 2 Te 5 exhibited the same tendency of decrease with increasing annealing temperature. Considering the increase in the Ge 2 Sb 2 Te 5 energy state owing to the presence

Our study demonstrated that anterior cervical fixation on BID is safe and effective in comparison with combined antero-posterior cervical fixation.