• Journal of Industrial Technology
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• v.29 no.A
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• pp.177-182
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• 2009

The inductor which is used at low frequency as the main part of magnetic ballast consists of an iron core, a bobbin and coil. The conventional inductor design method is not suitable for the magnetic ballast because it has various variables and is not a unique method for the magnetic ballast. Thus, this paper presents the optimal design method for a lamination type inductor using a magnetic ballast for Metal Halide Lamps. Also, the optimal inductor design method is researched for inductors of dimming ballasts and ignitors that have a gate-triggered structure using a SCR thyristor. By the simulation and experimental results, we showed that the proposed design methods is valid.

• Macromolecular Research
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• v.15 no.4
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• pp.302-307
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• 2007

The living radical polymerization of methyl methacrylate (MMA) by atom transfer radical polymerization, (ATRP) employing a $Fe(II)X_2/diphenyl-2-pyridyl$ phosphine (PyP) catalytic system (X=Cl, Br), was investigated using several initiators and solvents at various temperatures. Most of the polymerizations with the PyP ligand were well controlled, with a linear increase in the number average molecular weights ($M_n$) vs. conversion, with relatively low molecular weight distributions ($M_w/M_n=1.2-1.4$) throughout the reactions. The measured weights matched those of the predicted values. The ethyl-2-bromoisobutyrate (EBriB) initiated ATRP of MMA, with the $Fe(II)X_2/diphenyl-2-pyridyl$ phosphine catalytic system (X=Cl, Br), was better controlled in p-xylene at $80^{\circ}C$ than the other solvents used in this study.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.1 s.108
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• pp.1-9
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• 2005

The purpose of this study is to form a night-view at a university to satisfy users through case studies of four representative university campuses with analyzing the lighting conditions and facility satisfaction. The result of this study is following. From the present lighting status, there are 664(l9types) lightings at Kyunghee University, 350(17types) at Sungkyunkwan University and 437(l9types) at Ajou University. Main materials of the lightings are metal, iron and stainless. Moreover, most illuminants are white-colored metal-halide lamp. There is no specially designed lighting facility because ready-made goods were used. Furthermore, the locations of lightings are not suitable so some are useless. Most main spatial illuminations are not satisfying outdoor standard, so it can be concluded that the designs of present campuses are not carrying on with-out plans. From the result, present campus lighting does not satisfy the desire of users in aesthetic and functional point of view but consider the luminosity. However, even though the luminosity does not standardize the law. It is because the design does not reflect a suitable standard with desire of users and it does not have a long term plan. Moreover, the campus design has no study about development plan even though it has enough green area which has a potential possibility to overcome the lack of green areas in a city. Therefore, it is needed to design a comprehensive campus plan which satisfies the desire of students and residents with considering promotion of excitement and harmony through adjusting luminosity of the lighting facilities and supplying various lighting resources.