• The Journal of Bigdata
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• v.2 no.2
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• pp.115-128
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• 2017

Recently, Machine Learning Methods are widely used with high prediction performance. But if the limit of the data is solved by the statistical technique, It can, lead to higher prediction performance than the existing one. In this study, the SMOTE method is used to solve the imbalance problem in the longitudinal and imbalanced data. As a result, It, was confirmed that the prediction performance increases. Additionally, Although, studies on COPD have been actively conducted, only studies that are related to acute exacerbation have been conducted. So there are no studies on the prediction of acute exacerbation through multiple perspectives and predictive models for various factors. In this study, We examined the factors related to acute exacerbation of COPD and constructed a personalized specific disease prediction model.

• Journal of Family Relations
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• v.21 no.2
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• pp.77-96
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• 2016

Objectives: The aims of this study are to examine the associations between marital satisfaction and life satisfaction among Korean retirees in later life and to test whether the degrees of associations increased over time. Method: Nationally representative Korean Longitudinal Study of Ageing data from wave 1 (in 2006) to wave 4 (in 2012) was utilized and retirees in later life (65-89 years old, N=402) were analyzed. Latent growth modeling (LGM) and model constraint were applied using Mplus 7.3. Age, sex, household income, subjective health, depressive symptoms and elapsed time after retirement were included as control variables. Results: Linear unconditional LGM fitted the data well and showed gradual decrease in life satisfaction. Conditional LGM revealed significant associations between marital satisfaction and life satisfaction from time 1 to time 4. According to model constraint test, the size of associations between marital satisfaction and life satisfaction did not change with time. Conclusions: To sum up these results, the associations between marital satisfaction and life satisfaction were significant and relatively stable over time among retirees in later life. This study suggests one's spouse is a fundamental component of social convoy among Korean retirees in later life. Therefore, intervention programs targeted toward enhancing marital relationships among retirees' couples will help them to live a better life.

• Tuberculosis and Respiratory Diseases
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• v.76 no.4
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• pp.169-174
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• 2014

Background: The Korean Obstructive Lung Disease (KOLD) Cohort Study is a prospective longitudinal study of patients with chronic obstructive pulmonary disease (COPD), asthma, or other unclassified obstructive lung diseases. It was designed to develop new classification models and biomarkers that predict clinically relevant outcomes for patients with obstructive lung diseases. Methods: Patients over 18 years old who have chronic respiratory symptoms and airflow limitations or bronchial hyper-responsiveness were enrolled at 17 centers in South Korea. After a baseline visit, the subjects were followed up every 3 months for various assessments. Results: From June 2005 to October 2013, a total of 477 subjects (433 [91%] males; 381 [80%] diagnosed with COPD) were enrolled. Analyses of the KOLD Cohort Study identified distinct phenotypes in patients with COPD, and predictors of therapeutic responses and exacerbations as well as the factors related to pulmonary hypertension in COPD. In addition, several genotypes were associated with radiological phenotypes and therapeutic responses among Korean COPD patients. Conclusion: The KOLD Cohort Study is one of the leading long-term prospective longitudinal studies investigating heterogeneity of the COPD and is expected to provide new insights for pathogenesis and the long-term progression of COPD.

• Korean Journal of Social Welfare Studies
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• v.48 no.4
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• pp.59-89
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• 2017

Changes in the public welfare attitudes are very important to the welfare politics and policy. Considering that variability of public welfare attitudes has been ignored in previous studies, we analyzed welfare attitudes changes at individual level in Korea. Using the longitudinal data from the Additional Survey of 2010/2013/2016 Korea Welfare Panel Survey, we analyzed the changes in public welfare attitudes during 2010th-2016th years. Major findings are as follows. First, one of the findings from analysis is that the public welfare attitudes are very active and dynamic in Korea. This finding is contradiction to the results of the previous researches that are point to the stability or inertia of the public welfare attitudes in western welfare states and also in Korea. Second, occurrences of the welfare attitudes change are related with various individual characteristics; income status, occupation status, age, region, sex, political ideology, etc. These results from this study on the welfare attitudes change suggest that dynamics of the Korea welfare politics in recent years reflected the dynamic changes in public welfare attitudes. And, they suggest that Korea welfare politics are transformed from the traditional classes welfare politics to the new welfare politics which are influenced by various interests of the socio-demographic groups.

• Korean Journal of Social Welfare Studies
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• v.49 no.1
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• pp.5-28
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• 2018

Smoking is one of the important public health concerns because it is preventable causes regarding individuals' negative health consequences and increased social and economic cost. However, few studies have examined longitudinal patterns of stages of changes(SOC) in smoking behaviors among the general population. The purpose of the study is to explore the latent patterns of SOC over time among Korean adult smokers using the 2008-2016 Korea Welfare Panel Study. A repeated measure latent class analysis is employed in the present study. The finding of the present study are as follows: First, four latent groups were identified: (1) action/maintenance stage(33.6%), (2) contemplation/preparation to action/maintenance stage(14.8%), (3) continuously contemplation/preparation stage(29.6%), and (4) continuously pre-contemplation stage(22.1%). Second, the results of a multinomial logistic regression found that socio-demographic and clinical characteristics were associated with the identified longitudinal patterns of smoking behaviors. Compared to a continuously pre-contemplation stage, higher levels of depressive symptoms and drinking behavior were associated with increased odds of being in action/maintenance stage. The findings of the present study highlight that a tailored intervention is needed for individuals with continuously pre-contemplation stage and contemplation stage.

• Health Policy and Management
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• v.30 no.4
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• pp.493-504
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• 2020

Background: There have been many studies on the associations between body mass index (BMI) and cognitive function. However, no study has ever compared the associations across the methods of categorizing BMI. In this study, we aimed to fill the gap in the previous studies and examine whether the obesity paradox is valid in the risk of cognitive function. Methods: Of the 10,254 people aged 45 and older from the Korean Longitudinal Study of Ageing from 2006 to 2016, 8,970 people were finalized as the study population. The dependent variable was whether a person has a normal cognitive function or not, and the independent variables of interest were BMI categorized by the World Health Organization Western Pacific Regional Office (WHO-WPRO) method, the WHO method, and a 10-group method. Covariates included sociodemographic factors, health behavior factors, and health status factors. A generalized linear mixed model analysis with a logit link was used. Results: In the adjusted model with all covariates, first, in the case of BMI categories of the WHO-WPRO method, underweight (odds ratio [OR], 1.16; 95% confidence interval [CI], 1.15-1.17), overweight (OR, 1.36; 95% CI, 1.35-1.36), and obese (OR, 1.34; 95% CI, 1.33-1.34) groups were more likely to have a normal cognitive function than a normal-weight group. Next, in the case of BMI categories of the WHO method, compared to a normal-weight group, underweight (OR, 1.15; 95% CI, 1.14-1.16) and overweight (OR, 1.06; 95% CI, 1.06-1.07) groups were more likely to have a normal cognitive function; however, obese (OR, 0.62; 95% CI, 0.61-0.63) group was less likely to have it. Lastly, in the case of the 10-group method, as BMI increased, the likelihood to have a normal cognitive function changed like a wave, reaching a global top at group-7 (26.5 kg/㎡ ≤ BMI <28.0 kg/㎡). Conclusion: The associations between BMI and cognitive function differed according to how BMI was categorized among people aged 45 and older in Korea, which suggests that cognitive function may be positively associated with BMI in some categories of BMI but negatively in its other categories. Health policies to reduce cognitive impairment need to consider this association between BMI and cognitive function.

• Korean Journal of Child Studies
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• v.30 no.6
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• pp.195-208
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• 2009

The main body of research literature on peer relations has focused on its effects on children's psychosocial and emotional development from preschool period to adolescence. Topics of the research generally consist of peer acceptance/rejection, friendships, and peer victimization. In the review of domestic and international research conducted since late 1990, research trends and issues are described in this paper. Findings suggest some measures in interventions, prevention, and policies in promoting positive peer relations. Some social skill trainings are needed for children to react appropriately in peer relations and get along with their peers. In addition, there is a need for differentiation of the intervention programs by participants' roles in bullying situations and gender of children. Moreover, a longitudinal research is required to enhance the understanding of developmental changes in peer relations.

• Korean Journal of Child Studies
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• v.26 no.2
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• pp.121-134
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• 2005

Data were collected by peer nomination and sociometric nomination when children were in 4th grade and again two years later, Concurrent results of peer nominations were that prosocial children were more accepted while overtly/relationally aggressive children were more rejected by peers. Peer acceptance of males at Time 1 affected peer acceptance at Time 2. Peer rejection of females at Time 2 wasn't affected by overt aggression at Time 1. Cross-sectional results of social status were that rejected and controversial children showed higher levels of overt aggression than any other group. Popular children were most prosocial; rejected children were least prosocial. In the prospective view, aggressive males remained more rejected than any other group. Rejected children remained least prosocial.

• Korean Journal of Child Studies
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• v.19 no.2
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• pp.35-47
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• 1998

Negative life events, self-esteem, perceived social support, and maladjustment were studied longitudinally among late elementary children. Subjects were 241 boys and girls for depression and 258 for antisocial behavior. The instruments were the Adolescent Perceived Events Scale, the Rosenberg Self-Esteem Scale, the Social Support Scale for Children, the Revised Korean Version of the Center for Epidemiologic Studies' Depression Scale, and the Antisocial Behavior Scale. The results showed that the way variables were reciprocally related to one another in patterns over a period of one year differed by internal and external adjustment. For depression, depression at Time 1 had effects on self-esteem, social support, and depression at Time 2. For antisocial behavior, negative life events at Time 1 influenced negative life events, self-esteem, social support, and antisocial behavior at Time 2. The findings were discussed in relation to the effects of negative life events, self-esteem, and perceived social support on maladjustment.

• Asian Journal of Innovation and Policy
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• v.3 no.1
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• pp.25-49
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• 2014

We wanted to show the different group dynamics of factors for success and failure cases for technology commercialization in small technology-based firms. Existing studies are based on product level, project level, division level or firm level. We deal with technology level, and at small-technology-based firms. This is a longitudinal case study based on 8 cases from Korea. Our study on technology level is a first trial in success and failure studies unlike all existing studies. As a first step, we introduced new categories and factors such as technology attributes and CEO reflecting data, and especially a new concept of launch readiness level. Finally, we adopted correspondence analysis to show the group dynamics. The results are as follows; Technology factors are the most important factors. Second, resource-based factors are more critical in failure cases than success cases and technology factors are more critical to success.