• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1544-1546
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• 2003

In this study, composite materials were put to dry interfacial treatment by use of plasma technology. It has been presented that the optimum parameters for the best wettability of the samples at the time of generation of plasma were oxygen atmosphere, 0.1 torr of system Pressure, 100 W of discharge power, and 3 minutes of discharge time. The decrease in surface potential of charged samples by corona discharge indicates that the amount of accumulated electrical charges reduces and the charges that have been injected lessen rapidly when the duration of UV irradiation increases. The surface resistivity and the tensile strength of plasma treated samples, a longer UV irradiation time resulted in decreased insulation.

• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.1
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• pp.78-82
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• 2014

Power Transformers with more than one secondary winding are not uncommon in industrial applications. But new classes of applications where very large number of independent secondaries are used are becoming popular in controlled converters for medium and high voltage applications. Cascade H-bridge medium voltage drives and Pulse Step Modulation (PSM) based high voltage power supplies are such applications. Regulated high voltage power supplies (Fig. 1) with 35-100 kV, 5-10 MW output range with very fast dynamics (${\mu}S$ order) uses such transformers. Such power supplies are widely used in fusion research. Here series connection of isolated voltage sources with conventional switching semiconductor devices is achieved by large number of separate transformers or by single unit of multi-secondary transformer. Naturally, a transformer having numbers of secondary windings (~40) on single core is the preferred solution due to space and cost considerations. For design and simulation analysis of such a power supply, the model of a multi-secondary transformer poses special problem to any circuit analysis software as many simulation softwares provide transformer models with limited number (3-6) of secondary windings. Multi-Secondary transformer models with 3 different schemes are available. A comparison of test results from a practical Multi-secondary transformer with a simulation model using magnetic component is found to describe the behavior closer to observed test results. Earlier models assumed magnetising inductance in a linear loss less core model although in actual it is saturable core made-up of CRGO steel laminations. This article discusses a more detailed representation of flux coupled magnetic model with saturable core properties to simulate actual transformers very close to its observed parameters in test and actual usage.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.6
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• pp.255-261
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• 2005

Recently, the RF inductive discharge or inductively coupled plasma continues to attract growing attention as an effective plasma source in many industrial applications, the best known of which are plasma processing and lighting technology. To the point of lighting sources, the ring-shaped electrodeless fluorescent lamps utilizing an inductively coupled plasma have been objects of interest and research during the last decades, mainly because of their potential for extremely long life, high lamp efficacies, rapid power switching response. In this paper, maxwell 3D finite element analysis program (Ansoft) was used to obtain electromagnetic properties associated with the coil and nearby structures. The electromagnetic emitting properties were presented by 3D simulation software operated at 250 kHz and some specific conditions. The electromagnetic field in the ferrite core was shown to be high and symmetric. An LS-100 luminance meter and a Darsa-2000 spectrum analyzer were used in the experiment. According to data on the lamp tested using high magnetic field ferrite, the optical and thermal wave fields were shown to be high around the ring-shaped electrodeless fluorescent lamp. The optical or light field was high at the center of the bulb rather than around the ferrite core. The light conditions of the bulb were assumed to be complex, depending on the condition of the filler gas, the volume of the bulb, and the frequency of the inverter. Our results have shown coupling between the gas plasma and the field of the light emitted to be nonlinear.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1382-1384
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• 1995

In order to study the structure of RF glow discharge driven at 13.56MHz in argon, the discharge voltage, current and phase shift between them will be measured over a wide range of discharge parameters(gas pressure between 1mTorr and 50mTorr with discharge power between 20mW and 200W). In this paper, the dc glow discharge characteristics and plasma parameters of both FTS and CPMS systems are studied experimentally. It is found that for CPMS system discharge is stablized under wider ranges of magnetic field and pressure than for FTS system. The plasma density and electron temperature of the plasma for these two systems are in the range of $10^{10}{\sim}7{\times}10^{11}[cm^{-3}]$ and $3.5{\sim}6.5$[eV], respectively.

• Journal of Nutrition and Health
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• v.29 no.2
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• pp.192-198
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• 1996

This experiment was conducted to examine the effects of fish oil supplementation with low does on the lipid concentration and fatty acid composition of plasma and the fatty acid composition of plasma phospholipid and erythrocyte of infants. Among 18 breast-fed infants, 6 were in control group and 12 were in fish oil groups. The subjects in fish oil groups were nursed by their mothers who supplemented with fish oil 1.96g/d or 3.92g/d, respectively for 2 weeks from 10 to 12 weeks postpartum. The nursing mothers consumed their usual diets at home. Blood samples were collected at the final day of experiment. There were no significant changes in daily intakes of total lipid, triglyceride, free fatty acid, phospholipid and cholesterol of infants by fish oil supplementation. However, the content of EPA (eicosapentaenoic acid)increased and that of ARA (arachidonic acid) decreaed significantly in plasma PC(phophatidylchline). And also, there were tendencies to increase triglyceride concentration and to decrease cholesterol and phopholipid concentrations of plasma. As the above results, atherogenic index (AI) showed a tendency to decrease, but not significant. DHA (docosahexaenoic acid) and EPA contents in plasma PC and PE (phosphatidylethanolamin) as well as those of erythrocyte tended to increase. In these results, we concluded that fish oil supplementation with low dose to lactating women does not obviously affect of the plasma lipid concentrations and fatty acid composition of plasma PC and PE as well as erythrocyte. However the increase of EPA content of plasma PC and the tendency to increase DHA and EPA contents of plasma as well as erythrocyte membrane indicate that there may be some beneficial effect on infant lipid metabolism of fish oil intake of nutsing mother were increased.

• Journal of Society of Preventive Korean Medicine
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• v.8 no.2
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• pp.65-80
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• 2004

Objectives : CRATAEGII FRUCTUS(山査) is known as the substance which delays aging by the antioxidant effects. The purpose of this study is to investigate the effects of CRATAEGII FRUCTUS(山査) on antioxidant enzyme activities such as Thiobarbituric acid reactive substance(TBARS), Superoxide dismutase(SOD), Catalase(CAT), Glutathione peroxidase (GSH-px) in rat erythrocytes and blood plasma. Methods : Sprague-Dawley rats were divided into 3 groups, Normal group (supplied enough water and feeds only, Normal Group), D-galatose administered group(injected D-galatose 50mg/kg, 1time/day for 6 weeks, Control Group) and CRATAEGII FRUCTUS(山査) administered group (D-galactose 50mg/kg and CRATAEGII FRUCTUS(山査) extracts 85.0mg/200g 1time/day for 6 weeks, SS Group). Rats were sacrificed and TBARS, SOD, CAT, GSH-px, neutral fat and cholesterol were measured in rat erythrocytes and blood plasma. Results : There was no significant difference in the level of TBARS in the blood plasma between each experimental group. Red blood cell SOD activities were significantly different in each group. They were significantly decreased in the Control group compared to those of Normal and there was an increasing phenomenon in the SS group compared to the Control group. There was a significant difference in the activities of the red blood cell - glutathione peroxides in each group. There was a significant increase in the SS group compared to the Control group. Red blood cell catalase activities was no significant difference in each group. Plasma total lipid concentration was significantly different in each group. It was significantly increased in the Control group compared with the Normal group and it was decreasing in the SS group compared to the control group. Plasma triglyceride was not significantly different in each group. Plasma total cholesterol and Plasma HDL -cholesterol concentrations in the blood plasma were not significantly different in each group. Conclusions : According to the above results, it is considered that CRATAEGII FRUCTUS(山査) is effective in inhibiting lipid peroxides and increasing the activities of antioxidative(anti aging) enzyme in D-galactose induced aging rat.

• Journal of Korea Multimedia Society
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• v.18 no.1
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• pp.65-70
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• 2015

Particle accelerator has mainly used in nuclear field only because of the large scale of the facility. However, since laser-plasma particle accelerator which has smaller size and spends less cost developed, the availability of this accelerator is expended to various research fields such as industrial and medical. This paper suggests a visualization system to control the laser-plasma particle accelerator efficiently. This system offers real-time 3D images via convert HDF file comes from plasma data obtained from PIC simulation into OpenGL texture type to analyse and modify plasma data. After that, it stores high-resolution rendering images of the data with external renderer hereafter.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05c
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• pp.177-180
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• 2002

The purpose of this thesis is to develope buffer materials by the plasma polymerization method. In this article the buffer materials, plasma poly thiophene(PPTh) is used to study the interface of eter/organic in organic light emitting diodes(OLED). The interface of meter/organic materials is the important and critical objectives in development of OLED. The hole transport layer was N,N'-dipheneyl-N, N'bis-(3-methypheneyl)-1,1'dipheneyl-4,4'-diamine (TPD); the host material of mission layer was 8-tris-hydroxyquinoline aluminium (Alq3). When PPTh was inserted between ITO and TPD, emission efficiency increased.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.242-243
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• 2010

This paper investigates a power supply of medium voltage with enhanced ignition characteristics for plasma torch. Series resonant half-bridge topology is presented to be a suitable ignition circuitry. The ignition circuitry is integrated into the main power conversion system of a multi-phase staggered three-level dc-dc converter with a diode front-end rectifier. The plasma torch rated for 3MW, 2kA and having the physical size of 1m long is selected to be a high enthalpy source in waste disposal system. The steady-state and transient operations of plasma torch are simulated. The parameters of Cassie-Mary arc model are calculated based on 3D magneto-hydrodynamic simulations. Circuit simulation waveform shows that the ripple of arc current can be maintained within ${\pm}10%$ of its rated value under the existence of load disturbance. This power conversion configuration provides high enough ignition voltage around 5KA during ignition phase and high arc stability under the existence of arc disturbance noise resulting in a high-performance plasma torch system.

• Textile Coloration and Finishing
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• v.34 no.3
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• pp.165-172
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• 2022

Polypropylene(PP) is a textile material with various functions such as eco-friendliness, lightness, and elasticity. Although most synthetic fibers can be dyed and finished, but original PP is difficult to dye or finish due to its extremely hydrophobic properties, so its application expansion is limited. In order to solve this problem, dyeable PP was developed, and various researches on textiles for clothing such as mass production technology, fine fiberization and performance improvement are in progress. Plasma treatment is a processing method for modifying the surface of fabrics, and has effects such as hydrophilization, deepening color, improving adhesion, and surface polymerization. In this study, plasma treatment was applied to study changes in hydrophilization properties of dyeable PP, surface changes before and after plasma treatment and performance according to hydrophilization.