• The Journal of the Korea Contents Association
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• v.20 no.10
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• pp.458-469
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• 2020

Geriatric depression is associated with pathological changes in the brain and increases the risk of cognitive impairment or dementia. However, high cognitive reserve, such as high education, can delay or minimize clinical manifestations of pathologies involving the brain, so the effect of geriatric depression on cognitive impairment or dementia may vary depending on the education level. In this study, the author analyzed data from the Korean Longitudinal Study of Aging (KLoSA) to examine whether the effect of geriatric depression on cognitive function differed depending on education level. Among the 10,254 subjects registered in the KLoSA, the 4,905 subjects who met the inclusion criteria were analyzed by stepwise regression analysis. The results were as follows: first, depressive symptoms predicted low cognitive function after 12 years; second, the negative effect of depressive symptoms on cognitive function after 12 years was higher in the old adult group than in the young adult group; and third, the effect of age was significant only in the low-educated group. These results suggest that depressive symptoms in low-educated old adults may increase the risk of development of dementia in the long term.

• Journal of the Korean Society of Child Welfare
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• no.40
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• pp.41-71
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• 2012

The purpose of this study is to examine longitudinal impacts of various factors on happiness in primary school children. Specifically, attachment theory and ecosystems perspective were utilized for the purpose of this study. We used Korea Youth Panel Survey, which is a 5-year longitudinal data collected from fourth grade in elementary school to second grade in middle school Latent growth model was employed as the analytic method. The findings of this study are as follow: first, academic achievement, self-esteem, parent attachment, peer attachment, teacher attachment, and community attachment all decreased over the 5-year study period. Also, the intercept and the slope variance of variables were found to be statistically significant. This means that there are significant differences in the intercept and the slope of individuals. Second, self-esteem, parent attachment, and peer attachment were found to have cross-sectional influences on happiness. This means that self-esteem, parent attachment, and peer attachment are positively associated with happiness at the intercept. Also, self-esteem, parent attachment, teacher attachment, and community attachment were found to have longitudinal influences on happiness. This means that the higher levels of community attachment at the intercept is associated with slower the rate of decrease in happiness at the slope. In addition, faster rates of decrease in self-esteem, parent attachment, teacher attachment, and community attachment are associated with faster the rate of decrease in happiness. Third, this study conducted multiple group analysis with gender. The findings of this analysis revealed no significant differences in analytic models between males and females. Based on these findings, theoretical and practice implications with regard to happiness in primary school children are discussed.

• Journal of Family Resource Management and Policy Review
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• v.26 no.3
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• pp.65-85
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• 2022

This study aims to contribute to social work practice in understanding marriage and divorce as transitions and in helping women make meaningful decisions on whether to stay or leave the marriage by examining the factors that impact women's divorce decision making over time. This is a longitudinal study that used survival analysis by Korean Longitudinal Survey of Women and Families' panel data. Finally, cox regression analysis was used to evaluate the impact of each factor on divorce decision making, and accordingly, all regression models were appropriate for analysis.

• The Journal of the Korea Contents Association
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• v.20 no.6
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• pp.142-155
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• 2020

This study re-evaluated Malthusian regime which signifies a negative relationship between population and income by employing the trend for the population and the income of the world and panel analysis during 1820-2006 periods. Empirical evidence suggested that Malthusian regime was existed during 1900-1994 periods in the world economy. Even each country had experienced such regime in its own economic growth path. However, the population drastically decreased and output upsurged since 1995, Malthusian regime had not been revealed any more since then. Such phenomenon is mainly resulted from the output is rather increased geometrically when the population is decreased because of a social reason such as decreasing in fertility rate. In addition to this, the population contributes to the production not by a quantity but a quality which is embodied by capital. Particularly, when the population which is associated with demand side is counted, the population is said to be evolved continuously in economy.

• Journal of Korea Port Economic Association
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• v.36 no.2
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• pp.109-124
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• 2020

Using panel data on freight rates and ship prices in the dry freighter market from January 2015 to December 2019, this study investigates the characteristics of shipping industry fluctuations. The analysis aims at two aspects of academic contribution. First, this study analyzes the relationship between shipping indicators and ship price based on separate dry-bulk ships, while the previous research considered the overall shipping index and weighted average ship prices. Second, the VAR model for the causality test is extended to a heterogeneous mixed panel model capable of limiting coefficients. There is a peak estimated by removing the cross-correlation problem, which is mainly raised in panel data analysis, using bootstrap estimation and solving the problem of information loss due to differences in non-stationary data. An empirical investigation of the causal relationship between economic fluctuations and ship price shows that the effect on the ship price from the freight is significant at the 1% level. This implies that there is a one-way relationship with demand in the shipping industry rather than a bilateral relationship.

• Korean Journal of Social Welfare
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• v.58 no.4
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• pp.265-289
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• 2006

Purpose of this research is to analyze process that poverty influences in academic attainment of children. Data comes from Korea Youth Panel Survey 2004(Primary School 4). Analysis method is Structural Equation Modeling. Results show that poverty influences through process variable such as family function, neighborhood environment, private education, self-confidence. Findings from this study suggest that societal support for poor families contributes to improving academic attainment of child. Specially, such societal support needs to be centered to factors that mediates factor of poverty.

• Composites Research
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• v.20 no.4
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• pp.42-50
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• 2007

This paper describes the results of experiments and numerical simulation studies on the low-velocity impact damage of two different sandwich composite panels for application to bodyshell and floor structure of the BIMODAL tram vehicle. Square test samples of 100mm sides were subjected to low-velocity impact loading using an instrumented testing machine at four impact energy levels. Part of this work presented is focused on the finite element analysis of low-velocity impact response onto a sandwich composite panels. It is based on the application of explicit finite element (FE) analysis codes LS-DYNA 3D to study the impact response of sandwich structures under low-velocity impact conditions. Material testing was conducted to determine the input parameters for the metallic and composite material model, and the effective equivalent damage model for the orthotropic honeycomb materials. Numerical and experimental results showed a good agreement for damage area and the depth of indentation of sandwich composite panels created by the impact loading.

• The Journal of Korean Association of Computer Education
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• v.17 no.6
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• pp.103-113
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• 2014

This study designed and implemented a query model for consecutive analyses of dynamic multivariate graph data. First, the query model consists of two procedures; setting the discriminant function, and determining an alteration method. Second, the query model was implemented as a query system that consists of a query panel, a graph visualization panel, and a property panel. A Node-Link Diagram and the Force-Directed Graph Drawing algorithm were used for the visualization of the graph. The results of the queries are visually presented through the graph visualization panel. Finally, this study used the data of worldwide import & export data of small arms to verify our model. The significance of this research is in the fact that, through the model which is able to conduct consecutive analyses on dynamic graph data, it helps overcome the limitations of previous models which can only perform discrete analysis on dynamic data. This research is expected to contribute to future studies such as online decision making and complex network analysis, that use dynamic graph models.

• Journal of Convergence for Information Technology
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• v.11 no.10
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• pp.194-204
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• 2021

This study was conducted to find out the status and factors of private health insurance subscriptions by life cycle and to identify differences in medical usage behavior by life cycle. Using the SPSS 26 program as the 12th-15th (2016-2019) data of the Korea Welfare Panel, the difference subscriptions was identified as Chi-square by demo social and health characteristics of 58,223 people, and the factors affecting subscription were analyzed by polynomial logistic analysis and average analysis was performed for medical use behavior. As a result of the analysis, the biggest factor in purchasing private health insurance was household income, private health insurance coverage is the highest in growth period, and multiple subscriptions were made depending on household income. In youth, household income, spouse, and no disability, and middle age, household income, economic activities, spouses, and health levels were largely influential factors. The rate of private health insurance coverage in old age was the lowest, and low-income households, poor health levels, and people with disabilities were lower. The increase in medical use by private health insurance subscribers also occurred during growth and youth. It is necessary to strengthen the national health insurance coverage, and the role of private health insurance to supplement it should be established in time for the life cycle to complement each other, eliminating blind spots of medical security and maximizing people's health and well-being.

• Journal of the Economic Geographical Society of Korea
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• v.24 no.4
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• pp.400-410
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• 2021

This study analyzed the determinants of carbon dioxide emissions through the expanded STIRPAT model using panel data from 16 metropolitan cities and provinces in Korea from 2000 to 2019. After testing cross-sectional dependence and coefficient heterogeneity of panel data, we performed analysis using MG, CCEMG, and AMG estimation methods reflected these characteristics. The results of analysis using the AMG estimation method are as follows. The coefficients of income, population, and energy intensity were statistically significant with a positive sign, but urbanization was statistically insignificant. Reduction of carbon dioxide emissions in Korea can be achieved through an increase in energy efficiency and sustainable economic growth. It is necessary to establish a policy that can contribute to sustainable economic growth by inducing productivity improvement through technology innovation reducing carbon dioxide emissions in the long-term as well as building a low-carbon society through active development of carbon dioxide reduction technology.