• 전력전자학회:학술대회논문집
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• 전력전자학회 2006년도 전력전자학술대회 논문집
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• pp.409-412
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• 2006

EEFL can be driven by square wave driving method. A square wave is applied directly to both ends of EEFL by cascaded multi-stage full-bridge inverter. The various current shapes of lamp are achieved by various inductors between lamp and inverter. In this paper, it is newly investigated that the area of current directly influences the luminance. Furthermore, the 3-level square wave is considered to drive EEFL with self-discharge characteristics. The highest luminance efficiency is achieved by properly controlling the rate of self-discharge usage.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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• pp.175-176
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• 2000

Electric fields and the wall voltages in a surface-type AC PDP cell were measured using a Laser Induced Fluorescence Spectroscopy. For the condition of He 100Torr, 200V sustain voltage and 50kHz sustain frequency, the wall voltage dropped from about 50V to about -75V within $1{\mu}sec$ after the main discharge. And the wall voltage decreased with the rate of $10.8V/{\mu}sec$ due to the accumulation of the space charges after $1{\mu}sec$. But when the operating pressure was 40Torr, it increased with the rate of $4.5V/{\mu}sec$ because the diffusion effect of the wall charge on MgO surface was more dominant than the accumulation effect of the space charges. During the pulse-off period, the wall voltage decreased slightly due to the diffusion of the wall charge. When the sustain voltage was 250V, the self-erasing discharge occurred, and the absolute value of the wall voltage decreased rapidly just after the pulses were off, which was caused by the accumulation of the charges generated by the self-erasing discharge.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권10호
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• pp.515-522
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• 2004

In this study, we tried to investigate that the advantages of SOM(Self Organizing Map) algorithm such as data accumulation ability and the degradation trend trace ability would be adaptable to the analysis of partial discharge pattern recognition. For the purpose, we analyzed partial discharge data obtained from the typical artificial defects in GIS and XLPE power cable system through SOM algorithm. As a result, partial discharge pattern recognition could be well carried out with an acceptable error by use of Kohonen map in SOM algorithm. Also, it was clarified that the additional data could be accumulated during the operation of the algorithm. Especially, we found out that the data accumulation ability of Kohonen map could make it possible to suggest new patterns, which is impossible through the conventional BP(Back Propagation) algorithm. In addition, it is confirmed that the degradation trend could be easily traced in accordance with the degradation process. Therefore, it is expected to improve on-site applicability and to trace real-time degradation trends using SOM algorithm in the partial discharge pattern recognition

• Physical Therapy Rehabilitation Science
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• 제11권4호
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• pp.535-545
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• 2022

Objective: This study was conducted to identify predictive factors of physical activity in total hip arthroplasty patients, and to provide basic data for the developing physical activity promotion program for total hip arthroplasty patients. Design: Descriptive correlational research. Methods: Data were collected from August 2017 to May 2018. Surveys were distributed to 60 patients in a G university hospital located at J city, Gyeongsangnam-do. Data were analyzed by frequency, mean, standard deviation, t-test, ANOVA, Pearson's correlation coefficient, multiple regression analysis using SPSS 24 Win program. Results: The variables affecting the 4-week physical activity after discharge were age (β=.07), residence after discharge (β=-.22), cerebrovascular disease (β=-.13), mental and behavioural disease (β=-.11), taking antibiotic (β=-.26), walking ability (β=.41), nutritional status (β=.25), depression (β=.05). The eight variables accounted for 39.4% in the 4-week physical activity (F=4.49 p=.001). The variables affecting the 8-week physical activity after discharge were age (β=.06), waking ability (β=.34), nutritional status (β=.20), exercise self-efficacy (β=.05), depression (β=-.05). The six variables accounted for 28.0% in the 8-week physical activity (F=4.58, p<.001). Conclusions: The walking ability in discharge important to improve the physical activity, there is a need to develop an program to improve walking ability before discharge, in total hip arthroplasty. There is a need to develop a physical activity program to consistently participate in a community.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.2110-2112
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• 2000

This paper describes the self healing characteristics of a metalized polypropylene film(MPPF) used for energy storage capacitors. In the experiment, a d.c. voltage was applied to the MPPF, and the partial discharge inception voltages(PDIVs), the applied voltages at self healing, the burn out area and the current in the grounding conductor were measured and recorded. As a result, it was found that no PDs were found till the first pre-self healing occurred, and the applied voltage at self healing was increased with PPF thickness. Self healing was much more dependant on the shape of the air void than its diameter and the burn out area and the current in the grounding conductor at self healing was also increased with the applied voltage at self healing.

• Journal of Electrochemical Science and Technology
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• 제11권1호
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• pp.26-32
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• 2020

In this study, the side reactions that greatly affect the coulombic efficiency of a zinc-air secondary battery are quantitatively analyzed on the basis of the charging-discharging characteristics, open circuit self-discharge characteristics, and a series of calculations. In particular, the charge amounts consumed by water electrolysis and self-discharge during charging process are separately determined so that the charging efficiency (the amount of charge used in actual charging with respect to the applied charge amount) can be estimated, which would enable systematic understanding of the cause of coulombic efficiency degradation. Using two cells with different charging overvoltages, the validity of the proposed method can be assessed.

• 한국진공학회지
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• 제8권2호
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• pp.127-135
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• 1999

Nickel oxide films were prepard by using the electron beam evaporation technique. Coloring and bleaching experiments for cyclic durability were repeated in KOH electrolyte by cyclic voltammetry. Visible spectrophtometry was used to assess the stability of the transmittance in the degraded films. X-ray photoelectron spectroscopy results showed that the grain surface are oxygen-rich compared to the grain interiors in a NiO film. Open circuit memory of colored films is about 400hours in lN KOH. The rate of self discharge was evaluated by measuring the transmittance at 550nm of a fully oxidized NiO film. The rate of self discharge was increased polynomially with time and the film is nearly bleached after about 400hours. It was also found that the degraded film by repeated cycles in the KOH solution changed the grain shape of film surface The film prepared under a vacuum pressure of $3\times10^{-4}$ mbar was found to be rather stable when subjected to the repeated coloring and bleaching cycles in KOH electrolyte. Band theory applied to explain the electrochromic mechanism was discussed.

• 한국의료질향상학회지
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• 제8권2호
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• pp.160-171
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• 2001

Background : This study was conducted to compare the level of satisfaction between mothers who were educated on the care of newborns by video-taped method and those by verbal one before discharge. Methods : Fifty-two mother (verbal method group) from a free standing OB & GY hospital in Wonju City and forty-seven mothers (videotaped method group) from the OB & GY section of Wonju Christian Hospital(WCH) were selected for a study sample. The knowledge and understanding of newborn care and the degree of maternal satisfaction were assessed after the education by self-administered questionnaires. The opinions of the 11 nurses of WCH who were involved in the education were also collected by a questionnaire. Results : With respect of the level of understanding and satisfaction with the discharge education on newborn care, there is no significant difference between the videotaped educated group and verbal educated one. The correlation analysis of the video education group revealed a strong correlation between the score of understanding and satisfaction with the discharge preparation(r=0.409, p=0.01), and between the satisfaction scores for discharge preparation and discharge education(r=0.844, p=0.001). As for the verbal education group, the score of understanding also correlated significantly with both the score of satisfaction with the discharge education(r=0.272, p=0.001) and the discharge preparation(r=.680, p=0.001). Conclusions : This study showed that the discharge education to mothers regarding newborn care by a videotaped method does not improve the understanding or satisfaction of the mothers. However, the response to the mode of discharge education varies by the characteristics of the mothers. In conclusion, the characteristics of the mother should be considered in order to improve the understanding and knowledge of newborn care when the mode discharge education is chosen.

• 전기학회논문지
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• 제57권7호
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• pp.1218-1222
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• 2008

We investigate the effect of rise time of a pulse bias voltage on atmospheric plasma generation. With the faster rise time of the pulse bias, the glow discharge appears to be more uniformly generated along the electrodes. I-V measurement confirms that higher loading power can be obtained using the faster rise time. A new understanding for atmospheric plasma generation at a micro-gap electrode is suggested.

• Perspectives in Nursing Science
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• 제17권2호
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• pp.90-98
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• 2020

Purpose: This study examined the effects of breastfeeding education among preterm mothers. Methods: A nonequivalent control group, repeated measure, quasi-experimental study design was used. The participants comprised 46 preterm mothers recruited from the neonatal intensive care unit of a university hospital who were divided into two groups: 23 in the control group and 22 in the experimental group. The breastfeeding education program intervention to promote preterm mothers' self-efficacy used was devised based on the self-efficacy theory. The intervention program consisted of individual breastfeeding education with demonstrations and discharge education, and telephone follow-up education within one week after being discharged. The participants were surveyed before and after the intervention, and four weeks after being discharged from the newborn intensive care unit. Results: The intervention group showed a significant increase in breastfeeding self-efficacy compared with the control group (F=6.92, p=.003) and showed a significant increase in their breastfeeding attitude score (F=3.49, p=.039). Four weeks after discharge, the breastmilk volume of the intervention group increased significantly (t=-2.87, p=.006), and the same group continued to breastfeed more compared with the control group (χ²=4.50, p=.049). Conclusion: This study suggests that the preterm breastfeeding program had a positive effect on breastfeeding self-efficacy, breastfeeding attitude, and extending the breastfeeding period among preterm mothers.