• Journal of Power Electronics
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• v.16 no.2
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• pp.447-454
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• 2016

A single-ended primary-inductor converter (SEPIC) features low input current ripple and output voltage up/down capability. However, the switching devices in a two-level SEPIC suffer from high voltage stresses and switching losses. To cope with this drawback, this study proposes a three-level SEPIC that uses a low voltage-rated switch and thus achieves better switching performance compared with the two-level SEPIC. The three-level SEPIC can reduce switch voltage stresses and switching losses. The converter operation and control method are described in this work. The experimental results for a 500 W prototype converter are also discussed. Experimental results show that unlike the two-level SEPIC, the three-level SEPIC achieves improved power efficiency with balanced capacitor voltages.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.3
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• pp.496-502
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• 2006

The complexity of IC has rapidly increased as VLSI fabrication technology has grown up quickly. This paper proposes verification methods for data conflicts and protocol between IPs for SoC with coverage metrics. The high-level events is defined to cooperation between blocks or process statement in HDL, or a sequence of performing a job compared to low-level event. They are classified into two categories, resource conflicts and protocol or specification-dependent conflicts. And two coverage metrics used for code coverage in low-level event are proposed to verify the hish-level events. The events of resource conflicts can be detected by using statement coverage metric if global signal or variable has flags in a testbench program, and protocol-dependent events can be checked by data flow metric or path metric.

• Journal of Digital Convergence
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• v.18 no.8
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• pp.29-35
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• 2020

This study identified the impact of augmented reality advertising on attitude toward advertising and memory according to the type of presence and flow level. The presence (cognitive, emotional, media) and flow level (high vs. low) of the augmented reality(AR) advertising were set as independent variables and analyzed by Two-Way MANOVA. As a result of the research, first, the augmented reality advertising attitude was positive when the emotional presence and flow level were high. Second, when the flow level is high, the ARM such as product attribute information increases, but when the flow level is low, the evaluation-oriented GRM increases. Third, emotional presence increases GRM when the flow level is high, but ARM increases when the flow level is low. Fourth, the memory effect was low regardless of the flow level. In the future research, it would be desirable to produce augmented reality advertisements through virtual brands in the generalization of research.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.677-683
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• 2023

The purpose of the study was to estimate the trajectories of elementary school adjustment in grades 1 through 4. For the purpose, the Korean Children's Panel data were analyzed using potential growth model and the growth mixture model. As the result, the linear model was selected as the optimal model. The four potential groups were derived as trajectories: high-level maintenance, low-level maintenance, low-level increase, and high-level decrease. In terms of group distribution, the most children were in high-level maintenance group and then low-level maintenance, low-level increase, and high-level decrease in order. Based on the findings that trajectories of elementary school adjustment changes as children growth, we suggest that schools and families need to carefully investigate and support their school adjustment in individual levels.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.581-587
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• 2023

The purpose of this study was to analyze the change trajectory and latent class types of self-esteem in first to fourth grade elementary school students. For the purpose, the Korean Children's Panel data were analyzed using potential growth model and the growth mixture model. As the results, the linear change model was selected as the most appropriate model. The change trajectory was found to increase slightly as the grade increased. In addition, four latent class groups were derived through: 'high level-maintenance,' 'low level-increase,' 'high level-decrease,' and 'low level-maintenance.' Most children were in the 'high level-maintenance' group, followed by 'high level-decrease,' 'low level-increase,' and 'low level-maintenance' groups. Therefore, based on the results of the study, we suggest that educational institutions and local communities pay attention to trends in elementary school students' self-esteem and provide appropriate support for students in each class.

• Atmosphere
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• v.23 no.2
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• pp.187-204
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• 2013

This study analyzed the synoptic distribution and vertical structure about four cases of precipitation occurrences using NCEP/NCAR reanalysis data and upper level data of winter intensive observation to be performed by National Institute of Meteorological Research at Bukgangneung, Incheon, Boseong during 63days from 4 JAN to 6 MAR in 2012, and Observing System Experiment (OSE) using 3DVAR-WRF system was conducted to examine the precipitation predictability of upper level data at western and southern coastal regions. The synoptic characteristics of selected precipitation occurrences were investigated as causes for 1) rainfall events with effect of moisture convergence owing to low pressure passing through south sea on 19 JAN, 2) snowfall events due to moisture inflowing from yellow sea with propagation of Siberian high pressure after low pressure passage over middle northern region on 31 JAN, 3) rainfall event with effect of weak pressure trough in west low and east high pressure system on 25 FEB, 4) rainfall event due to moisture inflow according to low pressures over Bohai bay and south eastern sea on 5 MAR. However, it is identified that vertical structure of atmosphere had different characteristics with heavy rainfall system in summer. Firstly, depth of convection was narrow due to absence of moisture convergence and strong ascending air current in middle layer. Secondly, warm air advection by veering wind with height only existed in low layer. Thirdly, unstable layer was limited in the narrow depth due to low surface temperature although it formed, and also values of instability indices were not high. Fourthly, total water vapor amounts containing into atmosphere was small due to low temperature distribution so that precipitable water vapor could be little amounts. As result of OSE conducting with upper level data of Incheon and Boseong station, 12 hours accumulated precipitation distributions of control experiment and experiments with additional upper level data were similar with ones of observation data at 610 stations. Although Equitable Threat Scores (ETS) were different according to cases and thresholds, it was verified positive influence of upper level data for precipitation predictability as resulting with high improvement rates of 33.3% in experiment with upper level data of Incheon (INC_EXP), 85.7% in experiment with upper level data of Boseong (BOS_EXP), and 142.9% in experiment with upper level data of both Incheon and Boseong (INC_BOS_EXP) about accumulated precipitation more than 5 mm / 12 hours on 31 January 2012.

• Korean Journal of Adult Nursing
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• v.17 no.5
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• pp.732-742
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• 2005

Purpose: This study was conducted to compare self-rated health, health status, and health promotion behaviors between non-low income and low income elderly women in the urban setting. Method: The subjects of this study consisted of 668 Korean elderly women over 65years. The data was analyzed by the SAS(ver.8.02) computer program, and it included descriptive statistics, ${\chi}^2-test$, analysis of covariance, pearson correlation coefficient and multivariate logistic regression. Results: 1) The non-low income elderly women had significantly higher scores(self-rated health, health status, and health promotion behavior) than the low income elderly women. 2) In low income elderly women, age, number of children were the main effect factors of health status, and level of education, burden of medical expense were the main effect factors of health promotion behaviors. In non-low income elderly women, number of children was the main effect factors of health status, and level of education, level of pocket money were the main effect factors of health promotion behaviors. Conclusion: This study showed that the establishment of a health care system for elderly according to their social-economic level is very important for providing productive care apposite to the situation of elderly.

• Journal of the Korean Dietetic Association
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• v.25 no.2
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• pp.83-104
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• 2019

Elevated high-sensitivity C reactive protein (hs-CRP) levels and metabolic syndrome are considered important predictors of cardiovascular mortality. This study examined the influence of the alcohol consumption level on the hs-CRP level and the prevalence of metabolic syndrome in South Koreans. The study subjects were 3,884 participants (${\geq}19$ years) from the KNHANES in 2015. The subjects were divided into four groups according to their alcohol consumption; None (none-alcohol consumption), Low (less than 15 g/day), Medium (15~29.9 g/day), and High (over than 30 g/day). The odds ratio for high-risk hs-CRP of men was significantly lower in the Low or Medium groups compared to the None group. In women, the odds ratio for high-risk hs-CRP was not decreased in the Low or Medium groups but was significantly higher in the High group than in the None group. Compared to nondrinkers, the prevalence of metabolic syndrome was lower in the Low group and Medium group in both men and women, whereas it was significantly higher in the High group in men only. In particular, the prevalence of low HDL-cholesterol was lower in all drinking groups. When the confounding factors were adjusted, the odds ratio for low HDL-cholesterol appeared to decline in the Low groups in both men and women. On the other hand, in the Medium group, women showed an elevated odds ratios of high blood pressure (HBP) and high fasting plasma glucose but men showed an elevated odds ratios of HBP and high triglyceride levels. The overall results suggest that low alcohol consumption is more appropriate than medium alcohol consumption. Nevertheless, more study will be needed to evaluate the appropriate alcohol consumption level.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.3889-3894
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• 2012

The platform of railroad station for domestic passenger train has been operated at two categories like the platforms if low level(500mm, mainline) and high level(1,135mm, metropolitan subway line). To operate both metropolitan subway line and mainline railroad safely, it is essential to develop the doorstep equipment of railway vehicle regardless of low and high level platforms. On the other hand, the domestic test standard at durability and reliability of doorstep equipment has not been existed until now. This study aims at the development on doorstep equipment of telescopic sliding type for low and high level platforms. Durability analysis with VPD(Virtual Product Development) techniques are performed and the durability standard & qualification life through the rig test during no failure test time is examined in accordance with reliability qualification test.

• Child Health Nursing Research
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• v.23 no.2
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• pp.158-167
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• 2017

Purpose: The purpose of this study was to investigate the ecological factors influencing school adjustment of adolescents from low-income families. Methods: Secondary data analysis was performed using data of 1,321 low-income adolescents in 123 regions found on the Survey on Service Satisfaction with Community Child Care Center. Results: The results of multi-level analysis identified the factors influencing school adjustment of low-income adolescents as follows: individual-level factors were gender, grade in school, and emotional problem; an interpersonal-level factor was family structure; organizational-level factors were length of time attending center and satisfaction with the service of the center; community-level factors were region and perception of community. Conclusion: The results suggest that low-income adolescents' adjustment to school is influenced not only by individual factors but also by diverse environmental factors. Community factors suggest that more education support systems and leisure facilities for adolescents need to be built in small and medium cities. Strategies to enhance positive perception of community are also needed for this population. Further, it is necessary to develop multi-level interventions to improve the school adjustment of adolescents from vulnerable social groups.