• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.1
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• pp.56-63
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• 2000

Buck converter is considered to be one of the most widely used DC-DC converters due to its simple structure and high reliable performance. However, when it be combined with thin-film inductor, its own low inductance requires higher switching frequency in order to maintain optimum output ripple voltage and thus gives rise to extra switching losses. In view to overcoming such a technical inconvenience, soft switching fashion is suggested such as zero-voltage-switching of which an well known example is a Zero-Voltage-Switching clamp voltage(ZVS-CV) converter for which low inductance is imperatively required for ZVS operation. In order to support our suggestion, a 1W ZVS-CV buck converter is built by use of thin-film inductor, and then tested it. From the results of experiment and loss analysis, it is proved that the ZVS operation is well achieved and the measured efficiency of the converter is improved about 4% at full load comparing the conventional buck converter.

• Korean Journal of Medicinal Crop Science
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• v.13 no.5
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• pp.270-275
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• 2005

Superoxide dismutases (SOD) are metalloenzymes that convert $O_2^-\;to\;H_2O_2$. Rehmannia glutinosa is highly tolerant to paraquat-induced oxidative stress. The primary objective of this study was to characterize regulation of SOD gene expression in R. glutinosa in response to oxidative stresses and hormones. A full-length putative SOD clone (RgCu-ZnSOD1) was isolated from the leaf cDNA library of R. glutinosa using an expressed sequence tag clone as a probe. RgCu-ZnSOD1 cDNA is 777 bp in length and contains an open reading frame for a polypeptide consisted of 152 amino acid residues. The deduced amino acid sequence of the clone shows highest sequence similarity to the cytosolic Cu-ZnSODs. The two to three major bands with several minor ones on the Southern blots indicate that RgCu-ZnSOD1 is a member of a small multi-gene family. RgCuZnSOD1 mRNA was constitutively expressed in the leaf, flower and root. The expression of RgCu-ZnSOD1 mRNA was increased about 20% by wounding and paraquat, but decreased over 50% by ethylene and $GA_3$. This result indicates that the RgCu-ZnSOD1 expression is regulated differentially by different stresses and phytohormones at the transcription level. The RgCu-ZnSOD1 sequence and information on its regulation will be useful in investigating the role of SOD in the paraquat tolerance of R. glutinosa.

• Child Health Nursing Research
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• v.26 no.2
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• pp.286-295
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• 2020

Purpose: The purpose of this study was to review studies investigating the effect of bereavement care provided for parents in the neonatal intensive care unit. Methods: We conducted a literature review of databases (MEDLINE, Embase, Cochrane Library, and CINAHL) for studies published in English and four databases (RISS, KISS, NANET, and KoreaMed) for Korean studies. The selection criteria included original articles that evaluated the parents' perceptions or responses to bereavement care provided in the neonatal intensive care unit. Of 889 articles from the initial screening, 66 articles underwent full-text review and five articles were finally selected for analysis. Results: None of the studies was conducted in Korea. Only one study used a randomized control trial design. The forms of bereavement care reviewed included a provision of a memory package, grief information, and emotional and/or social support from peers or health care providers. The effectiveness of bereavement care was measured by including grief, social support, and depression. Conclusion: Bereavement care can be considered to be beneficial for relieving grief reactions and enhancing the personal growth of bereaved parents. Future research should assess the needs of bereaved parents in Korea. Nurses may play a role in developing the bereavement care for parents.

• Physical Therapy Korea
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• v.23 no.1
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• pp.1-10
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• 2016

Background: Patients with chronic low back pain (CLBP) functionally adapt to decreased postural control due to impaired processing of sensory information. Standing postural control has been the focus of recent research in CLBP. Change in postural control may be a risk factor for CLBP, although available studies are not conclusive. Objects: This study aimed to identify the role of partial weight supported treadmill training (PWSTT) in improving balance, dysfunction, and pain in patients with chronic low back pain. Methods: The study included 22 patients with CLBP. Patients in the control group ($n_1=8$) performed three 20 min stabilization exercise sessions per week, for 4 weeks. Patients in the full weight treadmill training group ($n_2=7$) performed treadmill training for 30 min after stabilization exercise. Patients in the PWSTT group ($n_3=7$) performed PWSTT with 20% of their body weight unloaded after stabilization exercises. By using the Biodex balance system, the dynamic balance abilities of the patients in the three groups were assessed in the quiet standing position under combined conditions of visual feedback (eyes open and closed) and platform stability (level 8). The Korean version of the Oswestry Disability Index and visual analogue scale score were used as the main measure. Results: The results of this study showed that dysfunction and pain were significantly improved in all groups. Although dynamic postural stability with eyes closed was significantly improved only in the PWSTT group (p<.05), no significant difference was found in the other groups. Conclusion: The results of this study indicate that PWSTT improved balance, dysfunction and pain in the patients with CLBP. Thus, this intervention is necessary for patients with CLBP with decreased postural control.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.10
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• pp.1197-1204
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• 2015

In this study, 8th Korea Welfare Panel data surveys utilizing 65 years age or older, problem drinking analyzed the impact on suicidal thoughts as a medium for depression and self-esteem. In the main analysis, First, Problem drinking appears to influence the level of statistically significant positive (+) of suicidal thoughts. Second, Depression was found to mediate the relationship between the full level of problem drinking and suicidal thoughts. Third, Problem drinking was found not appear to be significant influence on self-esteem is not the mediating effect of self-esteem. However, the higher level of problem drinking, the lower level of self-esteem, through the sign of regression coefficient is negative (-) potential of the relationship was confirmed. These results suggest that more systematic research is necessary for the elderly suicide with preparing for the elderly of problem drinking.

• Journal of Information Technology Services
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• v.13 no.4
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• pp.205-230
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• 2014

In recent years, the social network service (SNS) and the location-based social network service (LBSNS) industry is expanding and the competition within the field is increasing much more. Since 2010, the full-scaled studies of SNS and LBSNS have begun. With the growth of SNS and LBSNS markets, SoLoMo (Social-Local-Mobile) is also becoming the trend for applications in different fields. However, despite the importance of SoLoMo, there have been little studies on the characteristics of SoLoMo applications. The purpose of this research is to investigate the effect of characteristics and perceived privacy risk of mobile location-based SNS on intention to use SoLoMo applications. For the purpose, we proposed a SoLoMo service acceptance model with TAM (Technology Acceptance Model) and the characteristics of SoLoMo applications. The characteristics consist of three factors, i.e. SNS, location, and mobile-related factors. This study also considered a gamification and a perceived privacy risk factor influencing on SoLoMo service usage in our proposed research model. The results of our empirical analysis using partial least squares (PLS) method show that the characteristics of SoLoMo applications including SNS, location, and mobile-related features, gamification, and perceived privacy risk have partially an effect on intention to use SoLoMo applications. Based on these results, SoLoMo-related companies will be able to increase the usage of SoLoMo services by differentiating their own strategies with these factors influencing on SoLoMo services.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2002.11a
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• pp.140-142
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• 2002

This study was conducted to obtain some genetic information for developing superior Korean native chickens. Heterosis and combining ability effects were estimated with 1,080 progenies of full diallel crosses of 3 strains in Korean Native Chicken. The traits of egg productivity were Investigated, and heterosis effect, general combining ability, specific combining ability and reciprocal effect were analyzed model I of the Griffing's method 1. The general performance were 147.0 days in age at first egg laying, 71.8 eggs in egg numbers to 270 days, 50.1g in egg weight at 270 days, 75.6 in egg shape index, 356$\mu\textrm{m}$ in egg shell thickness, and 4.27kg/$\textrm{cm}^2$ in egg shell strength, respectively. According to result, heterosis effect revealed comparatively high in age at first egg laying, egg numbers, egg weight, and egg shell strength. The effects estimated highly in general combining ability for age at first egg laying, egg numbers, egg weight, egg shape Index and egg shell thickness, and in specific combining ability were egg numbers, egg weight and egg shell thickness, and in reciprocal effects for egg numbers, egg shape index, and egg shell thickness. This result could be used for developing Korean native chicken.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1797-1802
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• 2005

In this study, we were developed an accuracy of the proposed two dimensional statical inclinometer what used a position sensitive detector(PSD) by an error analysis. The inclinometer consists of a laser source, a mass, an optic-fiber, and a PSD. The gravity direction on a base platform of the inclinometer is changed by an unknown inclination angle. And a laser spot is moved from the origin to another position of a PSD following a variation of an optical path by the gravity. These processes enable the inclinometer to estimate the inclination angle from distance information of the moving spot. A design methodology on the basis of a sensitivity analysis was applied to improve the measurement performance such as a full measuring range and a resolution. But it still has error factors, so we analyze the uncertainty of the inclinometer to evaluate the systematic errors from alignments, assembly error and so on. The experimental performance evaluation about the design objectives as a measuring range and a resolution was performed. And the validity and the feasibility of the design process were certified by an experimental process. Systematic errors eliminated to improve the accuracy of the inclinometer by the corrected measuring model from the calibration process between the inclination angle and the PSD position instead of the nominal measuring model. The ANOVA(analysis of variance) confirmed the effect of eliminating the systematic errors in the inclinometer. From these methodologies, the proposed inclinometer was able to measure with a high resolution(35.14sec) and a wide range(from $-15^{\circ}\;to\;15^{\circ}$

• Journal of the Korean Vacuum Society
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• v.16 no.3
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• pp.192-196
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• 2007

ZnSe/CdSe/ZnSe single quantum wells with different well thickness were grown by hot wall epitaxy. The quantum well thicknesses were measured by TEM. The critical thickness of single quantum well layer was found to be about $9{\AA}$ from the intensities and the full-width at half maximum of photoluminescence(PL) spectra. When the thickness of quantum wells was less than the critical thickness, the Stoke's shift was confirmed from the comparison between PL and photoluminescence excitation spectra, and it may be due to the exciton binding energy. The PL peak energy dependence on the quantum well thickness was coincident with the theoretical values.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.355-362
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• 1999

With the ready access to the high resolution satellite image data, users of and areas covered by satellite image data are constantly on the rise world-wide. Korea will also be able to take full advantage of the satellite data once the KOMPSAT is successfully launched. Harmonizing satellite data production and application technology and users' needs, along with the guiding policy is essential for promoting satellite data use. Up to now, the Korean government has mainly concentrated on developing production technology for the satellite units. However, the imminent task of independent satellite data production demands a promotion policy for satellite data use. In this context, the policy is defined as an important medium for identifying the role and status of satellite image information at the national level and also Preparing the legal as well as systematic foundation for producing, building, distributing, and packaging satellite data. For example, in the countries with the advanced satellite technology, such as the United States, the United Kingdom, and Australia, digital ortho image and digital elevation model (DEM) are mandatorily included in the National Geographic Framework Data through policy measures. In addition, in order for the efficient provision of the satellite data, separate organization or agency is being in operation for the exclusive production and distribution of the satellite data. The present paper aims to examine the role and status of the satellite data as well as their current status and problems in Korea in reference to the National Spatial Data Infrastructure, and finally to provide the policy directions to promote the satellite data use in public sector on the basis of the preceding analyses.