• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2416-2418
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• 2010

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.113-113
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• 2008

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.582-584
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• 1998

IEEE1394 is an international standard that will integrate entertainment, communication, and computing electronics into consumer multimedia. IEEE1394 is a hardware and software for transporting data at 100,200, or 400Mbps. There are efforts to create speed improvements to 800 and muti-Gigabit speed s. An 980Mhz frequency synthesizer is proposed for high speed transport and designed by a 0.35um CMOS process.

• The Transactions of the Korean Institute of Power Electronics
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• v.28 no.1
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• pp.22-29
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• 2023

A grid-connected inverter can be used in grid-connected or stand-alone modes. Generally, a grid-connected inverter operates in a grid-connected mode, but the inverter operates in stand-alone mode if grid faults occur. In the stand-alone mode, the grid-connected inverter must supply electric power to a critical load that needs to receive stable power even though grid faults occur. Generally, three-phase loads are used as critical loads, but a single phase is configured in some cases. In these conditions, the critical load is required to unbalance the load power consumption, which makes the three-phase load voltage unbalancd. This unbalanced voltage problem can cause fatal problems to the three-phase critical loads, and thus must be addressed. Hence, this paper proposes an algorithm to solve this unbalanced voltage problem by the individual phase current control. The proposed method is verified using Psim simulation and experiments.

• Korean Journal of Materials Research
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• v.13 no.8
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• pp.497-502
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• 2003

Crystallographic characteristics and interfacial structures of $Al_2$$O_3$and $ZrO_2$dielectric films prepared by atomic layer chemical vapor deposition (ALCVD) were investigated at atomic scale by high-resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray spectroscopy (EDS)/electron energy-loss spectroscopy (EELS) coupled with a field-emission transmission electron microscope. The results obtained from cross-sectional and plan-view specimens showed that the $Al_2$$O_3$film was crystallized by annealing at a high temperature and its crystal system might be evaluated as either cubic or tetragonal phase. Whereas the $ZrO_2$film crystallized during deposition at a low temperature of ∼$300^{\circ}C$ was composed of both tetragonal and monoclinic phase. The interfacial thickness in both films was increased with the increased annealing temperature. Further, the interfacial structures of X$ZrO_2$$O_3$and $ZrO_2$films were discussed through analyses of EDS elemental maps and EELS spectra obtained from the annealed films, respectively.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.24 no.3
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• pp.96-104
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• 1998

It was possible to produce W/O/W one step multiple emulsion on the system which satisfied following conditions. 1. 1-5％ of hydrophilic liquid surfactant over HLB20 and lipophilic liquid surfactant which has HLB 3∼5 2. Non wax copolymers as oil thickener 3. More than 0.5％ of carbomer as aqueous thickener 4. The manufacturing process which neutralize the dispersed carbomer (2.0％ in water), after emulsifying. For the selective addition into inner and outer aqueous phase, we melted the glucose in water before emulsifying. Using an Anthrone analysis method, we analyzed the encapsulation yield of glucose in inner water phase. It was possible to raise the water encapsulation yield of the multiple emulsion through the following conditions. 1. Using of anionic hydrophilic surfactant(HLB 40) and lipophilic surfactant (HLB 3∼5) 2. Controlling the ratio of hydrophilic surfactant and lipophilic surfactant 3. Strengthening interface with increase of non wax oil thickener. When the separated adding process of glucose was adopted, approximately 85％ of glucose was added selectively within inner aqueous phase.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.24 no.3
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• pp.105-110
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• 1998

In the make-up product, Eye-shadow products have several purposes of enhancing product quality such as providing the beauty (variation of shape, clean appearance), feeling, continuity and adhesion. In this paper, newly developed wet type back injection press process is introduced so as to increase higher value products which providing various the beauty. The solvent takes an essential role to provide the fluidity of the powder bulk during the pressed-process of wet type pressed product. In this study, the effect of solvent in the oil binder was investigated, And the higher quality condition of the wet type pressed product was built to apply cosmetic preparation. Firstly, the system was designed powder phase as non treated pigment. The oil binder phase is categorized as hydrocarbons(Mineral oil, Squalane), Silicones(Methicone, Dimethicone ), esters (Octyldodecanol, Octyl Dodecyl Myristate). The solvent phase used was C 7-8 isoparaffin and Isopropyl Alcohol. The interaction of oil binder and solvent is investigated by measuring mass of final oil binder and the each solubility parameter. It was found that the higher the solubility the higher the degree of change in the final composition of the oil binder. In order to maintain the quality of the final product, the solvent used in pressed-process should be hydrophobic with oil binder.

• Journal of Information Technology Application
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• v.3 no.3
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• pp.91-106
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• 2001

We propose a software-reliability growth model incoporating the amount of uniform and Weibull testing efforts during the software testing phase in this paper. The time-dependent behavior of testing effort is described by uniform and Weibull curves. Assuming that the error detection rate to the amount of testing effort spent during the testing phase is proportional to the current error content, the model is formulated by a nonhomogeneous Poisson process. Using this model the method the data analysis for software reliability measurement is developed. The optimum release time is determined by considering how the initial reliability R($\chi$ 0) would be. The conditions are ($R\chi$ 0)＞$R_{o}$ , $P_{o}$ ＞R($\chi$ 0)＞ $R_{o}$ $^{d}$ and R($\chi$ 0)＜$R_{o}$ $^{d}$ for uniform testing efforts. deal case is $P_{o}$ ＞($R\chi$ 0)＞ $R_{o}$ $^{d}$ Likewise, it is ($R\chi$ 0)$\geq$$R_{o}$ , $R_{o}$ ＞($R\chi$ 0)＞R(eqation omitted) and ($R\chi$ 0)＜R(eqation omitted)for Weibull testing efforts. Ideal case is $R_{o}$ ＞ R($\chi$ 0)＞ R(eqation omitted).

• Journal of Powder Materials
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• v.15 no.5
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• pp.371-377
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• 2008

This paper deals with the phase analysis of $MgB_2$ bulk using spark plasma sintering process after ball milling. Mg and amorphous B powders were used as raw materials, and milled by planetary-mill for 9 hours at argon atmosphere. In order to confirm formation of $MgB_2$ phase, DTA and XRD were used. The milled powders were fabricated to $MgB_2$ bulk at the various temperatures by Spark Plasma Sintering. The fabricated $MgB_2$ bulk was evaluated with XRD, EDS, FE-SEM and PPMS. In the DTA result, reaction on formation of $MgB_2$ phase started at $340^{\circ}C$. This means that ball milling process improves reactivity on formation of $MgB_2$ phase. The $MgB_2$ MgO and FeB phases were characterized from XRD result. MgO and FeB were undesirable phases which affect formation of $MgB_2$ phase, and it's distribution could be confirmed from EDS mapping result. Spark Plasma Sintered sample for 5 min at $700^{\circ}C$ was relatively densified and it's density and transition temperature showing super conducting property were $1.87\;g/cm^3$ and 21K.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.4
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• pp.227-230
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• 2007

The multi-lamellar and liquid crystal structures have drawn great public attention in the functional cosmetic and skin-related medicinal areas recently. The structure of an emulsion containing aqueous phase as a binding water and fixed oil phase components forming an association compound of the multi-lamellar structure can reconstruct the intercellular lipid lamellar structure in the stratum corneum and restore barrier function of the skin. In this study, we investigated the beneficial effect of bio-mimic liquid crystal emulsions (BLCE) containing higher fatty alcohol, lecithin, and cholesterol on the skin barrier function, and evaluated its cytotoxicity.