• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1129-1130
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• 2011

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1073-1074
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• 2011

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.5
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• pp.499-506
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• 2019

This paper is concerned with the operating stability of 7kW inverter using SIC hybrid module and verifies the validity of the simulation results by comparing the result of the loss equation and the simulation result, Simulation results using Si module and SiC hybrid module are compared to compare switch loss and diode loss. Through the loss equation calculation, the conduction loss of SiC Hybrid module is 168W, switching loss is 9.3W, diode loss is 10.5nW, When compared with the simulation results, similar values were shown. As a result of comparing the simulation results of the Si module and the SiC Hybrid module, The total device loss of the Si module was 246.2W, and the total device loss of the SiC Hybrid module was 189.9W. The loss difference was 56.3W, which was about 0.8W. thereby verifying the reverse recovery characteristics of the SiC SBD. In addition, temperature saturation test was conducted to confirm the stability of SiC Hybrid module and Si module under high temperature saturation, In the case of the Si module, the output power was stopped at 4kW, and the SiC Hybrid module was confirmed to operate at 7kW. Based on this, an efficiency graph and a temperature graph are presented, and the Si module is graphed up to 4kW and the SiC Hybrid module is graphed up to 7kW.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.6
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• pp.1397-1403
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• 2011

In this paper, fabrication of sample holder was studied for an analysis of electromagnetic(EM) wave property in W-band(75 GHz~110 GHz). First of all, a propagation theory of EM wave was considered in the rectangular waveguide, and measurement technique was suggested for analysis of characteristics. A sample holder using in W-band was designed and fabricated, and used for analysis of material property and absorption ability using RAM samples. As a result, the sample holder test was verified exactly for measuring EM wave property of RAM sample. In the future, the proposed sample holder would like to be used for the EM wave property analysis in W-band.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.29 no.1
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• pp.135-150
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• 2003

This study is described the stabilizing technology of water-in-oil (w/o) emulsion and the mechanism of emulsification with quaternium-18 hectorite (Q-18 HTRT) by swelling action. When Q-18 HTRT is dispersed in oil, it swells and constructs card-house structure adding ethanol, and formation of water phase is caused by hydrogen bonding. The gelling activities of Q-18 HTRT were excellent such as mineral oil, squalane, cetostearyl isononanoate, isostearic acid, cetyl octanoate, octyl dodecanol and so on. Especially, when oil gel containing Q-18 HTRT passed one to three times by Roll mill. It made the W/O emulsion cream (W/O-ECRM) having 2.0 w/w% of Q-18 HTRT and also produced the control sample (control) including 3.0 w/w% of cetyl PEG/PPG- l0/l dimethicone. The stability of after 24 weeks, Hardness of W/O-ECRM dropped 7.48%, whereas hardness of control went down 57 71%. As a result of these test emulsification of W/O-ECRM is superior compared with control. In cosmetic, 0-18 HTRT can use as suspending agent, oil adsorbent, emulsifying agent, dispersing agent, viscosifier and pigment.

• Archives of Pharmacal Research
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• v.28 no.12
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• pp.1400-1404
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• 2005

The aim of the present study was to develop the aqueous parenteral formulation containing propofol using o/w microemulsion systems. Propofol itself was chosen as the oil phase and its content was fixed to 1$\%$, w/w. Pseudoternary phase diagrams were constructed to obtain the concentration range of surfactant and cosurfacatnt and the optimum ratio between them for microemulsion formation. Consequently, the suitability of the chosen microemulsion system as a parenteral formulation was evaluated from the stability and hemolysis tests on that. Among the surfactants and cosurfactants screened, the mixture of Solutol HS 15-ethyl alcohol (5/1) showed the largest o/w mocroemulsion region in the phase diagram. When 1 $\%$ (w/w) of propofol was solubilized with 8$\%$ (w/w) of Solutol $HS^{circledR}$??? 15-ethyl alcohol (5/1), the average droplet size (150 nm) and the content of propofol in the systems were not significantly changed at 40$^{circ}C$ for 8 weeks. The hemolysis test showed that this formulation was nontoxic to red blood cells. In conclusion, propofol was successfully solubilized with the o/w microemulsion systems.

• Culinary science and hospitality research
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• v.7 no.2
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• pp.181-194
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• 2001

Dried noodles was manufactured by wheat flour and saline solution mixture. At this time, saline solution mixture was used for simple saline solution and mixture(blending ratio of PNSO and emulsifier=2:1, w/w) of both pine needle seasoning oil (PNSO) manufactured by autoclaving method and food emulsifier. Water absorption ratio, volume expansion ratio and water soluble solid matters content were decreased, but cooking time was prolonged, respectively. According to, suitable treating amount of PNSO was 2-3%(w/w) level. On organoleptic test, the peculiar green color was appeared in cooked noodles of PNSO treating groups. The surface was slickly, chewy rheology and texture were improved at PNSO treating cooked noodle. During 20-30 minutes after cooking, chewy characteristics was maintained the treating groups more than PNSO 2%(w/w). At the result, this PNSO treatin dried noodle samples were suitable at the institutional food service as well as dining hal1 for the case of large scale's kitchen work.

• Nutrition Research and Practice
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• v.7 no.4
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• pp.294-301
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• 2013

In this study, we examined the hepatic anti-steatosis activity of carnosic acid (CA), a phenolic compound of rosemary (Rosmarinus officinalis) leaves, as well as its possible mechanism of action, in a high-fat diet (HFD)-fed mice model. Mice were fed a HFD, or a HFD supplemented with 0.01% (w/w) CA or 0.02% (w/w) CA, for a period of 12 weeks, after which changes in body weight, blood lipid profiles, and fatty acid mechanism markers were evaluated. The 0.02% (w/w) CA diet resulted in a marked decline in steatosis grade, as well as in homeostasis model assessment of insulin resistance (HOMA-IR) index values, intraperitoneal glucose tolerance test (IGTT) results, body weight gain, liver weight, and blood lipid levels (P < 0.05). The expression level of hepatic lipogenic genes, such as sterol regulating element binding protein-1c (SREBP-1c), liver-fatty acid binding protein (L-FABP), stearoyl-CoA desaturase 1 (SCD1), and fatty acid synthase (FAS), was significantly lower in mice fed 0.01% (w/w) CA and 0.02% (w/w) CA diets than that in the HFD group; on the other hand, the expression level of ${\beta}$-oxidation-related genes, such as peroxisome proliferator-activated receptor ${\alpha}$ (PPAR-${\alpha}$), carnitine palmitoyltransferase 1 (CPT-1), and acyl-CoA oxidase (ACO), was higher in mice fed a 0.02% (w/w) CA diet, than that in the HFD group (P < 0.05). In addition, the hepatic content of palmitic acid (C16:0), palmitoleic acid (C16:1), and oleic acid (C18:1) was significantly lower in mice fed the 0.02% (w/w) CA diet than that in the HFD group (P < 0.05). These results suggest that orally administered CA suppressed HFD-induced hepatic steatosis and fatty liver-related metabolic disorders through decrease of de novo lipogenesis and fatty acid elongation and increase of fatty acid ${\beta}$-oxidation in mice.

• Journal of the Korea Concrete Institute
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• v.14 no.4
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• pp.449-456
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• 2002

Recently, the application of high strength and high performance concrete has been gradually increased as an important construction material for high rise and huge scaled construction. However, high performance concrete has undesirable characteristics of spalling subjected to high temperature due to its dense microstructure content. A spalling by fire brings surface failure and falling off concrete member. It is considered that spalling by fire should be taken into account for the safety of the concrete structure under fire. Therefore, in this paper, tests are carried out using high performance concrete containing polypropylene(PP) fiber in order to improve the fire resistance performance. PP fiber contents and member sizes are varied. According to experimental results, as for the influence of PP fiber contents, all the test specimens without PP fiber show entire failure in W/C of 35％, while they show nearly sound shape except some kinds of surface fracture in W/C of 55％. When PP fiber is contained more than 0.07％, favorable prevention effects of spatting by fire are obtained. As for the effects of test specimens size, it tends to increase the possibilities of spatting by fire as test specimens become larger. And spatting by fire at the edge of test specimens occurs more frequently than at the surface of test specimens. Residual compressive and tensile strength shows 45∼65 ％ of its original strength at W/C of 35％, and 30∼40％ at W/C of 55 ％.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.3
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• pp.91-96
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• 2014

Modern electronic circuits are becoming more vulnerable to damage by surges, and it is required to improve the impulse withstand voltage performance of electrical and electronic equipment. This paper presents the impulse withstand voltage performance of lighting equipment connected to power lines, and the impulse withstand voltage tests for fluorescent lamp, LED lamp and halogen lamp were carried out according to the reference standards under normal service conditions. To conduct performance tests against lightning surge, a combination wave ($1.2/50{\mu}s$ voltage - $8/20{\mu}s$ current) was employed. The test surge was applied between lines or between line and ground of the specimen to be measured. The test surge was applied synchronized at the peak value of the positive and negative AC voltage waves. As a consequence, some specimens satisfied the impulse withstand voltage test criteria, but lighting equipment such as 36W fluorescent lamps, 5W and 5.5W LED lamps and 50W halogen lamp were damaged at the test voltage levels between power lines. It is needed to improve the qualities of lighting equipment to satisfy EMC immunity requirements of equipment for general lighting purposes.