• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.05b
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• pp.106-109
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• 2005

The $(Sr_{1-x}Ca_x)TiO_3$(SCT) thin films are deposited on Pt-coated electrode (Pt/TiN/$SiO_2$/Si) using RF sputtering method with substitutional contents of Ca. The optimum conditions of RF power and Ar/$O_2$ ratio were 140[W] and 80/20, respectively. Deposition rate of SCT thin film was about 18.75[$\AA$/min]. The dielectric constant was increased with increasing the substitutional contents of Ca, while it was decreased if the substitutional contents of Ca exceeded over 15[mol%]. The capacitance characteristics had a stable value within ${\pm}4$[%] in temperature ranges of -80~+90[$^{\circ}C$].

• Transactions on Electrical and Electronic Materials
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• v.8 no.6
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• pp.278-282
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• 2007

In the complex insulation system that is used in extra high voltage(EHV) devices, according to the trend for electric power equipment of high capacity and reduction of its size, macro interfaces between two different bulk materials which affect the stability of insulation system exist inevitably. In this paper, the dielectric strength decrease of the macro interfaces between epoxy and ethylene propylene diene terpolymer(EPDM) was estimated by using the applied voltage to breakdown time characteristics. Firstly, the AC short time dielectric strength of specimens was measured at room temperature. Then, the breakdown time was measured under the applied constant voltage which is 70% of short time breakdown voltage. With these processes, the life exponent n was determined by inverse power law, and the long time breakdown voltage can be evaluated. The best condition of the interface was LOS(low viscosity(350 cSt) silicone oil spread specimen). When 30 years last on the specimens, the breakdown voltage was estimated 44% of the short time breakdown voltage.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.4
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• pp.348-353
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• 2008

Most of the high voltage insulation systems, such as the power cable joint having hetero interface, are composed of more than two different insulators to improve insulating performance. The partial discharge(PD) in these hetero interface is expected to affect the total insulation performance. Thus, it is important to study electrical properties on these interfaces. This study described the influence of copper and semiconductive substance defects on $\Phi$-q-n distribution between the interface of the model cable joints to classify PD source. PD was sequentially detected for 600 cycles of the applied voltage. The K-means cluster analysis has been analyzed to investigate the $\Phi$-q-n distribution. The skewness-kurtosis(Sk-Ku) plot from K-means clustering results was defined to quantify cluster distribution and classify distribution patterns. The Sk-Ku plot is composed of skewness and kurtosis along abscissa and ordinate which indicate the asymmetry and the sharpness of distribution. As a result of the Sk-Ku plot, it was confirmed that the data was distributed in 1st 2nd and 3rd quadrant at copper foreign substance defect, but in case of semiconductive foreign substance, the data was distributed in 2nd quadrant only.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.4
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• pp.372-372
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• 1996

The torsional vibration of the propulsion shafting system equipped with viscous damper is investigated. The equivalent system is modeled by a two mass softening system with Duffing's oscillator and the vibratory motion is described by non-linear differential equations of second order. The damper casing is fixed at the front-end of crankshaft and the damper's inertia ring floats in viscous silicon fluid inside of the camper casing. The excitation frenquency is proportional to the rotational speed of engine. The steady state response of the equivalent system is analyzed by the computer and for this analyzing, the harmonic balance method is adopted as a non-linear vibration analysis technique. Frequency response curves are obtained for 1st order resonance only. Jump phenomena are explained. The discriminant for the solutions of the steady state response is derived. Both theoretical and measured results of the propulsion shafting system are compared with and evaluated. As a result of comparisions with both data, it was confirmed that Duffing's oscillator can be used in the modeling of the propulsion shafting system attached with viscous damper with non-linear stiffness.

• Journal of Korean Medicine for Obesity Research
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• v.12 no.1
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• pp.1-8
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• 2012

Objectives The purpose of this study was to examine the quality of life of overweight & obese women using SF-36 Methods We studied 244 patients visiting Gangdong Kyung Hee University Hospital from 1st April 2011 to 30th November 2011. The subjects were categorized in two groups, normal group(n=158) and overweight & obesity group(n=86). We studied the difference of SF-36 scores between two groups by independent samples t-test and correlation between anthropometry and SF-36 scores by Pearson's correlation coefficient test using SPSS for windows(version 13.0). Results Overweight & obesity group significantly showed lower quality of life in the domains of physical functioning, bodily pain, and social functioning than normal group. Some of body weight, fat mass, body mass index, percent body fat, fat distribution and quality of life in the domains of physical functioning, role-physical, bodily pain, general health, social functioning, role-emotional significantly showed negative correlation coefficient. Conclusions The results suggest that overweight and obese women tend to show lower quality of life.

• Journal of Korean Academy of Nursing
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• v.47 no.6
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• pp.744-755
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• 2017

Purpose: This study was performed to develop an infection prevention education program for child care teachers and to verify its effects. Methods: The study was conducted using a nonequivalent control group with a pretest-posttest design. Four private daycare centers (2 centers per city) that were alike in terms of the number of children by age, number of child care teachers, and child care environment were chosen. Participants were assigned to the experimental group (n=20) or control group (n=20). As a part of the program, visiting education (90 min) was provided in the 1st week, and smartphone application education (10 min) was provided thrice a week, in the 2nd and 3rd weeks. Results: Child care teachers' self-efficacy for infection prevention revealed a significant interaction effect between the group and time of measurement (F=21.62, p<.001). In terms of infection prevention behavior, a significant difference was observed between the experimental and control groups (z=-5.36, p<.001). Conclusion: The program implemented in this study was effective in improving the infection prevention self-efficacy and infection prevention behavior of child care teachers. Thus, this program may be effective in enhancing their infection control.

• Journal of the Korean Home Economics Association
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• v.49 no.2
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• pp.37-49
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• 2011

The present study investigated the semantic and syntactic processes in Korean children's sentence comprehension by measuring event-related brain potentials(ERPs). The subjects were 18 right-handed, healthy native Korean children(1st graders), who were free from any hearing problems. While the children listened to the auditory sentence stimuli, ERPs were recorded with the electrodes mounted in a 'Quik-Cap' on the subject's head. The ERP data were recorded and analyzed using the NeuroScan 4.3 and EEGLABv6.03b programs. For statistical analyses, descriptive statistics, three-way repeated measures ANOVA, and t-tests were performed using a SPSS 15.0 PC program. The results indicated that semantic violations elicited a negativity (N400) ranging from 300 to 500 msec. For syntactic violations, children displayed a positivity (P600) ranging from 900 to 1,100 msec. The discovery of N400 and P600 in semantic and syntactic processes respectively, confirmed the suggestion that Indo-European and Korean languages share a common mechanism for sentence comprehension.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.6
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• pp.1646-1654
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• 2007

The aim of this study was to investigate the effects of several herbal prescriptions in patients with allergy or atopic disease, such as atopic dermatitis, asthma and allergy rhinitis and others, on the blood immunological parameters and to verify the safety of long-term use of herbal medicine. Eighty one patients with allergy or atopy disease who taken herbal medicine at least for 2 months were compared with patients who taken same medicine with no allergy & atopy disease (n=14) and normal healthy subjects (n=22). According to the comparison of immunological parameters change, the data showed that herbal medicine decreased IgE (P=0.003), Eosinophil ratio (P<0.001) and count (P<0.001) of White Blood Cell (WBC) and did not affect to the liver cell enzymes in blood. This results indicated that herbal medicine decreased immune hypersensitivity and improved chronic inflammation related to blood immunological parameters of allergy or atopy diseases. In addition, herbal medicine seemed to be safe to the liver function for long-term use.

• The Korean Journal of Physiology
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• v.7 no.2
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• pp.17-20
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• 1973

A study was planned to see if the Panax Ginseng has any influence upon the general activity of rats. Seventeen male rats (mean body weight: 204 g) was divided into a ginseng group (N=9) and a saline group (N=8). Once a day for 5 days they received subscutaneously 0. 5m1/100g body weight of ginseng extract solution (4 mg of ginseng alcohol extract in 1 ml of saline), and same amount of saline, respectively. For 20 days beginning from the 1st day of medication on, each rat received activity measurement by means of beam interruption method. Following results were obtained : 1. Activities at night (6 p.m. to 6 a.m. next morning) and in 24hours on the 10 th, 12th, and 13 th day were significantly increased in the ginseng group compared with activities of the saline group. 2. Summed total night and 24-hour activities observed for 15 days after termination of medication were also significantly augmented in the ginseng group compaired with those of the saline group, although no remarkable difference existed between the 2 groups with regard to the summed total daytime activity. It is inferred that the ginseng augments general activity of rats especically at night.

• Journal of Korean Medical Ki-Gong Academy
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• v.5 no.1
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• pp.22-39
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• 2001

This study is designed to compare the effect of a needle with the magnet on body. We took the skin temperature of the belly with digital infrared thermographic imaging while we sticked needle and apply magnets on L14. We made experiments on 40 healthy male volunteers for one month. We classified control group not acupuncture or magnet adhering(CON). acupuncture group on left and right L14(LA). and the permanent magnet group adhering to left and right(LM). And LM is divided into S-polar permanent magnet group(LMS) and N-polar permanent magnet group adhering to left and right L14(LMN). When we observed that temperature changed with time, the skin temperature of th belly in CON descended significantly but LM, LMS and LMN is not changed significantly. As mentioned above. we observed that the needles on L14 affected the change of temperature on the belly, and conjectured that the appliance of magnets had the same results. If the mechanism depends on the meridian of body and energy. we suppose that the appliance of magnets and needles has same effects.