• The Korean Journal of Applied Statistics
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• v.30 no.5
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• pp.615-632
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• 2017

Unlike randomized trial, statistical strategies for inferring the unbiased causal relationship are required in the observational studies. The matching with the propensity score is one of the most popular methods to control the confounders in order to evaluate the effect of the treatment on the outcome variable. Recently, new methods for the causal inference in latent class analysis (LCA) have been proposed to estimate the average causal effect (ACE) of the treatment on the latent discrete variable. They have focused on the application study for the real dataset to estimate the ACE in LCA. In practice, however, the true values of the ACE are not known, and it is difficult to evaluate the performance of the estimated the ACE. In this study, we propose a method to generate a synthetic data using the propensity score in the framework of LCA, where treatment and outcome variables are latent. We then propose a new method for estimating the ACE in LCA and evaluate its performance via simulation studies. Furthermore we present an empirical analysis based on data form the 'National Longitudinal Study of Adolescents Health,' where puberty as a latent treatment and substance use as a latent outcome variable.

• Korean Journal of Community Nutrition
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• v.5 no.2
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• pp.185-192
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• 2000

As the percentage of the elderly in the population increases, research to identify the nutritional and health status of the elderly, to understand the factors influencing on them, and to delay aging have been done actively. It is necessary for these studies to be longitudinal. This study was carried out to assess the change of health-related habits such as dietary behaviors and smoking, alcohol drinking and exercising habit, and health status between previous study(1991/1994) and post study(1998) for middle-aged men and women living in Chonju. For the present study, the data of 63 pairs(23 men and 40 women) were analyzed. They were 11 men and 12 women followed up from 82 men and 100 women surveyed in 1994. Mean ages in the 1991/4 and 1998 studies were 53.6y(range 42-63y) and 59.0y(range 46-72y) respectively. The survey was conducted with interview using a questionnaire including dietary behaviors and health-related habits, and anthropometric measurement and blood test for analyzing biochemical indices in 1991/4 and 1998. To understand these changes over time, $\chi$$^2$-statistics, t-test and paired t-test were analyzed with an SAS package program. As people age, there were significantly decreases in the proportions to eat lightly salted foods and drink alcohol. Significant longitudinal increases in triceps skin fold thickness, ${\gamma}$-GPT and HDL-cholesterol and significant decrease in hemoglobin value were noted over time in both men and women. In addition a significant decrease in blood glucose level was noted over time in women. Weight, blood glucose and total cholesterol increased significantly with age in those had had breakfast regularly or those had not used more slat at the table in the past. From this study, were found out the subjects of this study had relatively desirable health-related habits. But as improper health-related habits are likely to result in inappropriate health status(eg, increase in WHR, triglyceride, total cholesterol and LDL-cholesterol), it is recommended that nutrition education in necessary as soon as possible to meet the health elderly.

• Korean Journal of Social Welfare Studies
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• v.45 no.2
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• pp.375-402
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• 2014

The purpose of this study is to investigate the longitudinal change pattern of life satisfaction and the effect of social capital of people with disabilities. For this study, data were drawn from the panel data employment for the disabled from the second to the fifth. It includes 3,206 person with disabilities. The methodology adopted in this study is the latent growth curve modeling. The findings of this study are as follows: First, Life satisfaction has been decreased over years and the difference between individuals of life satisfaction of people with disabilities were statistically significant. Second, The intercept of life satisfaction in the disabled was positively associated with network, and slope of life satisfaction was negatively related to network. Third, social participation positively influences the intercept of life satisfaction but, no significant affect to the slope. Based on results of the study, practical implication and the political-approach to interventions for the better life satisfaction of the disabled are being discussed.

• Korean Journal of Social Welfare Studies
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• v.48 no.2
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• pp.303-329
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• 2017

This study aimed to explore the trajectories of computer game use of school age children and to identify the related predictors. The data for this study used Korean Children and Youth Panel data covering from the second year to the sixth year of elementary school. A total of 1,959 participants were analyzed. Latent class growth model was employed to explore the trajectories of computer game use and multinomial logistic regression was conducted to identify the significant predictors. Main results indicated that three types of trajectories were identified: low game using group, high initial using-fluctuating group, and high increasing game using group. Each group was found to be associated deferentially with sex, aggression, attention deficit, main caregiver's education, siblings, parent absence after-school, neglecting, family income, family trip, school grades, and peer relationship. Based on these findings, this study emphasized the importance of predictive intervention for the game user among early school age children and suggested useful practical strategies.

• Korean Journal of Social Welfare Studies
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• v.47 no.4
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• pp.309-332
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• 2016

This research attempts to calculate the vertical equity of National Health Insurance Contribution of locally provided policy holders by abilities to pay. Also, this longitudinal study examined the influence of abilities to pay and demographic characteristics on the health insurance premium. Using data from the Korea Welfare Panel Study, this study followed the self-employed households who continued to participate in the survey from 2011 to 2015. Kakwani's index of progressivity was measured as a measure of vertical equity and panel regression analysis was conducted by STATA program. The results of this research are as follows. First, from 2011 to 2015, the values of kakwani's index were negative according to composite income, which meant some levels of regressiveness of contribution. Secondly, panel regression analysis showed that the lowest household of composite income had a significantly negative effect on premiums, which also meant regressiveness. Based on the results, the author suggested political discussions on reorganizing the system of imposing the National Health Insurance contribution.

• Journal of Korean Public Health Nursing
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• v.36 no.2
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• pp.227-239
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• 2022

Purpose: This study aimed to examine the differences in the reciprocal causal relationship between cognitive function and depressive symptoms depending on whether older adults lived with others or alone. Methods: We used panel data retrieved from the sixth (Time 1) and seventh (Time 2) waves of the Korean Longitudinal Study of Aging (KLoSA). The study sample included 2,638 older adults living with others and 628 older adults living alone. We conducted cross-lagged panel analyses (CLPA) to identify the bidirectional causal relationship between cognitive function and depressive symptoms in the groups of older adults living with others and those living alone. Results: In the group of older adults living with others, cognitive function and depressive symptoms showed significant reciprocal relationships. In the group of older adults living alone, although the CLPA confirmed that higher levels of depressive symptoms at Time 1 influenced lower levels of cognitive function at Time 2, cognitive function at Time 1 was not associated with depressive symptoms at Time 2. Conclusion: The results suggest that the strategies for preventing cognitive decline and depressive symptoms should be developed according to whether the older adults live alone. Moreover, further studies should identify factors influencing depressive symptoms among older adults living alone, which will ultimately enable the management of depressive symptoms.

• Korean Journal of Child Studies
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• v.31 no.3
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• pp.117-138
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• 2010

The purpose of this study was to investigate the effects of early storybook reading intervention participation on the first graders' language abilities in low income families. The subjects consisted of 148 first graders and their primary caregivers. The intervention group was composed of 100 first graders who participated in the early storybook reading intervention program in childcare or kindergarten. The comparison group comprised 48 first graders from equivalent social and economic backgrounds, who did not participate in the program. The language abilities of the children were tested and questionnaires regarding the home literacy environment, children's reading activities at home and parents' perceptions of their children's reading behaviors were completed by the children's primary caregivers. The data were analyzed by means of structural equation modeling. The results indicated that early intervention participation was directly associated with children's higher language abilities in first grade and indirectly influenced the children's language abilities through the home literacy environment, children's reading activities at home and parents' perceptions of their children's reading behaviors.

• Korean Journal of Human Ecology
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• v.21 no.6
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• pp.1059-1082
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• 2012

The purpose of this study was to analyze the trends, research methodology and findings of various researches on family resilience published in Korea over the past 13 years. A total of 93 publications related to family resilience between 1999 and June of 2012 were analyzed; 72 journal articles and 21 doctoral dissertations which had not been published in academic journals. The results are as follows; (1) There has been steady increase in the number of related researches since 1999, with a significant increase since the mid-2000s as various nontraditional families emerged and the perception of family problems began to change. (2) With regards to the methodology, the majority of the studies were empirical, using quantitative methods in both data collection and analysis. Most measurement scales employed were based on inventories developed by foreign researchers. (3) The research subjects encompass a wide range of individuals and groups from both vulnerable families and families from the general population. Additionally, some researches focused on special interest areas including program development & evaluation and scale development. Although research on family resilience has increased in quantity, there needs to be more qualitative, longitudinal and theory grounded studies on different families and individual types to better understand family resilience in depth. In addition, specific measurement scales reflecting the unique Korean family culture should be developed. Other challenges and suggestions for future research on family resilience are discussed.

• Korean Journal of Biological Psychiatry
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• v.28 no.2
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• pp.36-49
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• 2021

Suicide is a leading cause of death worldwide, especially among adolescents and young adults. Considering this fact, it is imperative that we understand the neural mechanisms underlying suicidal thoughts and behaviors in youth from a neurodevelopmental perspective. In this review, we focused on the magnetic resonance imaging studies that examined the neural correlates of suicidal ideations (SI) or attempts (SA) in youth. We reviewed twenty-three cross-sectional studies reporting the structural and functional alterations in association with SI or SA among adolescents and young adults with various mental disorders. The previous literature suggests that the dorsolateral prefrontal cortex, anterior cingulate cortex, and ventral frontolimbic circuit, may play an important role in the pathophysiology of suicidal behavior in youth through altered top-down control over emotion and impulsivity. Future studies with a longitudinal design and using multimodal imaging techniques may be of help to identify novel therapeutic targets specific for youth with suicidal thoughts and behaviors.

• Journal of Korean Academy of Nursing
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• v.24 no.2
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• pp.278-302
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• 1994

This article reviewed and analyzed 39 studies on self efficacy theory applied to health related behavior. The following analysis was done : 1) study subjects 2) measurement tools 3) analysis according to the type of research design(intervention re-search, explanatory research). Some findings are summarized as follows : The study subjects were both healthy people in various developmental stages and patients with various illnesses. The health related behaviors examined in the studies were also various including exercise, smoking cessation, self care behaviors, etc. The measurement of self efficacy was done with specific tools in most studies. In the tools, activities that measured the health behavior domain were listed according to increasing difficulty or contexual arrangement or in combination of both of them The analysis of 17 intervention research studies showed that generally the intervention program increased the self efficacy level of subjects and then the increased strongly self efficacy influenced behavioral changes. Most studies used more than one intervention method for increasing the self efficacy level. these were derived from sources of self efficacy suggested by Bandura. The analysis of 21 explanatory research studies showed that self efficacy strongly influenced behavior change and persistence. The major independent variable to affect the self efficacy was performance accomplishment in the past. Self efficacy explained more of the variance in health related behavior when it was applied with the variables in the health belief model, health promotion model, and reasoned action theory. On the basis of the above findings, the following suggestions are made : 1. For a desirable research design, self efficacy should be the intervening variable. That is, desirable designs would include intervention-self efficacy-behavior in intervention research studies and antecedent-self efficacy-behavior in explanatory research studies. 2. More prospective, longitudinal studies are needed to test the effect of self efficacy on persistence in health related behavior. 3. Studies comparing the effects of intervention methods are needed for each health related behavior, subject group, and context. 4. It is necessary to develop a reliable, valid measurement tool for self efficacy for each health related behavior. 5. Studies to differenciate the effect of self efficacy from that of outcome expectation on the health related behavior are necessary. 6. The antecedents of self efficacy should be investigated further.