• The Korean Journal of Applied Statistics
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• v.35 no.6
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• pp.703-724
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• 2022

Although longitudinal studies mainly produce multivariate longitudinal data, most of existing statistical models analyze univariate longitudinal data and there is a limitation to explain complex correlations properly. Therefore, this paper describes various methods of modeling the covariance matrix to explain the complex correlations. Among them, modified Cholesky decomposition, modified Cholesky block decomposition, and hypersphere decomposition are reviewed. In this paper, we review these methods and analyze Korean children and youth panel (KCYP) data are analyzed using the Bayesian method. The KCYP data are multivariate longitudinal data that have response variables: School adaptation, academic achievement, and dependence on mobile phones. Assuming that the correlation structure and the innovation standard deviation structure are different, several models are compared. For the most suitable model, all explanatory variables are significant for school adaptation, and academic achievement and only household income appears as insignificant variables when cell phone dependence is a response variable.

• The Korean Journal of Applied Statistics
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• v.29 no.5
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• pp.873-885
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• 2016

Onions are grown in a few specific regions of Korea that depend on the climate and the regional characteristic of the production area. Therefore, when onion yields are to be estimated, it is reasonable to use a statistical model in which both the climate and the region are considered simultaneously. In this paper, using a spatial panel regression model, we predicted onion yields with the different weather conditions of the regions. We used the spatial auto regressive (SAR) model that reflects the spatial lag, and panel data of several climate variables for 13 main onion production areas from 2006 to 2015. The spatial weight matrix was considered for the model by the threshold value method and the nearest neighbor method, respectively. Autocorrelation was detected to be significant for the best fitted model using the nearest neighbor method. The random effects model was chosen by the Hausman test, and the significant climate variables of the model were the cumulative duration time of sunshine (January), the average relative humidity (April), the average minimum temperature (June), and the cumulative precipitation (November).

• Journal of the Korean Society of Child Welfare
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• no.40
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• pp.229-253
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• 2012

The present study examined the capacity of Korean adolescents' self-esteem to buffer against the negative impact of academic stress on self-control. Based on the prevention science perspective, the conceptual framework for this study was developed from the strength model of self-control. Data for the present study were taken from the fourth wave of Korean Youth Panel Study. A sample of 2,169 students in the eleventh grade was analyzed to identify relationships between the study variables. As expected, self-esteem moderated the association between academic stress and self-control. Implications for the study findings are discussed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4566-4575
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• 2015

This study aimed to develop a model to explain the factors influencing father's parenting stress, and to verify the appropriateness of the model. The participants included 1609 fathers with a 5-year old. The study used 2012 Panel Study of Korean Children (PSKC) by the Korea Institute of Child Care and Education (KICCE), and analyzed with SPSS and AMOS programs. The analysis showed that first, father's income and parental efficacy were negatively related with parenting stress and father's depression and marital conflict were positively related with parenting stress. Second, father's parenting stress was directly and indirectly impacted by parental efficacy and their child's temperament. These results suggest that father education are needed for promoting positive paternal mental health and parental efficacy, to reduce parenting stress of fathers.

• Journal of the Economic Geographical Society of Korea
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• v.26 no.3
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• pp.310-323
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• 2023

Urbanization and income distribution issues are global interest, and the results of studies on the impact of urbanization on income inequality are different for each country and period. This study analyzes the impact of urbanization on income inequality using regional data from 2000-2021. In particular, serial correlation, spatial dependence, and common factor effects of the Gini coefficient are confirmed and analyzed through a dynamic spatial panel regression model. As a result, urbanization has a positive effect on reducing income inequality. Therefore, it is necessary to continuously promote regional urbanization to improve the income distribution problem. Areas with already high urbanization rates should reduce income inequality by narrowing the wage gap by expanding training opportunities for low-skilled workers, and need to come up with measures to prevent counter-urbanization.

• Journal of the Korean Regional Science Association
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• v.40 no.2
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• pp.21-38
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• 2024

Understanding the interrelationship between regional population dynamics and cultivated land is crucial for promoting regional economic vitality and enhancing food security. While prior research often addressed population migration and changes in crop area separately, this study employs a Panel Vector Auto Regression Model to examine the dynamic interaction between regional population shifts, changes in crop area, and the influx of foreign workers in agriculture. The results reveal a reciprocal relationship between population influx and crop area, indicating a negative impact on each other. Moreover, the analysis demonstrates that an expansion in crop area, particularly in field cultivation, significantly correlates with an increase in foreign workers. These findings underscore the mutual influence of labor shortages and diminished land availability in agriculture, with the influx of foreign workers potentially offering a positive impact on addressing structural challenges in rural areas.

• Korean Journal of Culture and Social Issue
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• v.28 no.3
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• pp.331-352
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• 2022

This study used a latent growth curve models(LGCM) to examine longitudinal changes in youth's game usage, self-control and the longitudinal mediation effect of adaptive game use in the relationship between game usage and self-control. A four-year longitudinal data of 863 adolescents from the Game User Panel Survey, provided through participation in the 2019 Game User Panel Research Conference hosted by the Korea Creative Contents Agency, was used to verify the longitudinal mediation effect of adaptive game use. SPSS 21 was used to verify the normality of variables from each wave, and to conduct correlation analysis. Mplus 6.12 was used to verify the longitudinal mediation effect. The results are as follows. First, game usage, self-control and adaptive game yielded linear temporal growth. Second, latent growth curve models showed that the direct effect of game usage on self-control was insignificant, but game usage had a significant indirect effect on self-control through adaptive game use. Continuous adaptive gaming increased self-control. Third, sobel test results showed that both the initial value and change rate of adaptive game use had a full-mediation effect, confirming the longitudinal mediation effect. This study verified the longitudinal change of self-control affected by change in game usage and adaptive game use.

• Environmental and Resource Economics Review
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• v.25 no.2
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• pp.229-253
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• 2016

To achieve the socially optimum level of renewable generation, governments should design renewable policies to induce renewable technologies competitive with conventional generation technologies. And to do that, it is needed to understand how each policy has been effective in promoting renewables for power sector. In most of the literatures, there are two key limitations that they did not considered autocorrelation problem using the amount of generation from renewables as a dependent variable and technology innovation which needs to be preceded technology adoption. In this study, I try to overcome these two problems by using dynamic panel model and adding an additional variable for technology innovation. According to the result, FIT has been effective rather than RPS in promoting renewables for generation and I found the possibility that the counterintuitive results which commonly appeared in existing studies might be due to the two limitations mentioned above.

• Journal of the Korean Data and Information Science Society
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• v.27 no.5
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• pp.1147-1154
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• 2016

Impact of Korea train express (KTX) on the regional economy in Korea has been studied by many researchers. Current research is limited in the lack of quantitative research using a statistical model to study the effect of KTX on regional economy. This paper analyses the influence of KTX to the household final consumption expenditure, which is one of important regional economic index, using spatial panel regression model. The spatial structure is introduced through spatial autocorrelation matrix using adjacency of KTX connection. The result shows a significant effect of Korea train express on the regional economy.

• The Journal of the Convergence on Culture Technology
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• v.5 no.2
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• pp.77-82
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• 2019

The purpose of this study is to analyze the relationship between the controlling shareholding ratio and the business diversification of savings banks The difference in this study is the analysis of the relationship between the controlling shareholding ratio of the savings bank and the business diversification using panel data. In this study, the semi-annual financial statements for the period 2014-2018 were used on the basis of a sample of 79 saving banks. The research model is analyzed using random effects generalized linear square (GLS) model considering the autocorrelation problem. As a result of the empirical analysis, it is estimated that the relationship between the controlling shareholding ratio of the savings bank and the business diversification is significant (+). This is the result of supporting the hedging hypothesis.