• Journal of Periodontal and Implant Science
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• v.49 no.4
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• pp.206-214
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• 2019

Purpose: The purpose of this study was to examine the association between the intake of semi-solid yogurt and periodontitis in Korean adults using a national database. Methods: The data analyzed in this study are a subset of the sixth Korean National Health and Nutrition Examination Survey conducted in 2015 by the Korea Centers for Disease Control and Prevention. The sample size for this study was 4,727. We collected data on sociodemographic characteristics, oral health-related variables, oral and general health status, and intake of semi-solid yogurt. Semi-solid yogurt intake (YI) was calculated by multiplying the frequency of YI over the previous week by the average intake per serving. We assessed periodontal conditions using the Community Periodontal Index (CPI) and defined periodontitis as a CPI score ${\geq}3$. Multivariate logistic regression analyses were performed after adjusting for sociodemographic variables, and oral and general health behaviors and status. Results: The mean weekly YI among those without periodontitis ($1.03{\pm}0.06cups$) was significantly higher than among those with periodontitis ($0.77{\pm}0.08cups$) (P<0.001). Individuals who consumed more than 2 cups of yogurt per day were 76% less likely to have periodontitis than those who consumed less than 1 cup of yogurt per week after adjusting for all covariates (odds ratio, 0.24; 95% confidence interval, 0.10-0.60). Conclusions: We found a significant association between increased intake of semi-solid yogurt and periodontal health. We therefore recommend daily consumption of semi-solid yogurt as a probiotic to improve periodontal health. Further longitudinal studies are required to elucidate plausible mechanisms through which probiotics impact periodontal disease, considering both periodontal pathogens and clinical periodontal parameters.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.507-514
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• 2018

This study utilized latent growth curve modeling to investigate the trajectories of adolescent life satisfaction changes in middle and high school students. The effects of self-esteem, career identity, school learning activity, gender, and household earnings on life satisfaction changes were examined. Data was obtained from the Korea Child Youth Panel Survey (KYCPS), a longitudinal study following students for 7 years. Year 3-6 data was utilized. Results found that the life satisfaction trajectory resulted as a quadratic model in which individual differences were significant. Second, school learning activity used as a time variant variable had a positive significant effect on life satisfaction each year. Third, gender and self-esteem as time invariant variables had significant effects on initial levels while self-esteem had effects on the slope and quadratic change. Further implications and research issues are discussed.

• Journal of Navigation and Port Research
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• v.43 no.1
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• pp.16-22
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• 2019

This study proposed estimation methods for weight and center of gravity of small fishing vessels. Weights loaded on small fishing vessels were divided into fixed weights such as crew, fishing gear, and variable weights such as fuel, fresh water, provision, bait, and fish. Based on statistical analyses with weight data of several small fishing vessels, weight, longitudinal center of gravity (LCG), vertical center of gravity (KG) of each item were represented as linear functions of vessel gross tonnage. In addition, weighting factors of variable weights were added on estimation formulas in accordance with vessel loading conditions, e.g. full load departure condition. Estimation methods were verified using actual small fishing vessel data.

• Journal of Periodontal and Implant Science
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• v.49 no.2
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• pp.60-75
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• 2019

The primary aim of this systematic review was to assess the evidence on periodontal disease progression after treatment in patients receiving supportive periodontal therapy (SPT) and to identify predictors of clinical attachment level (CAL) loss. A protocol was developed to answer the following focused question: In adult patients treated for periodontitis, what is the disease progression in terms of CAL loss after surgical or non-surgical treatment? Randomized controlled clinical trials, prospective cohort studies, and longitudinal observational human studies with a minimum of 5 years of follow-up after surgical or non-surgical treatment that reported CAL and probing depth changes were selected. Seventeen publications reporting data from 14 investigations were included. Data from 964 patients with a follow-up range of 5-15 years was evaluated. When the CAL at the latest follow-up was compared to the CAL after active periodontal therapy, 10 of the included studies reported an overall mean CAL loss of ${\leq}0.5mm$, 3 studies reported a mean CAL loss of 0.5-1 mm, and 4 studies reported a mean CAL loss of >1 mm. Based on 7 publications, the percentage of sites showing a CAL loss of ${\geq}2mm$ varied from 3% to 20%, and a high percentage of sites with CAL loss was associated with poor oral hygiene, smoking, and poor compliance with SPT. The outcomes after periodontal therapy remained stable over time. Disease progression occurred in a reduced number of sites and patients, mostly associated with poor oral hygiene, poor compliance with SPT, and smoking.

• Journal of Family Relations
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• v.23 no.2
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• pp.111-131
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• 2018

Objectives: This study examined the effects of residential proximity to adult children on the mental and physical health of middle-aged and older parents. The study also evaluated whether the parental age and gender of the adult child in closest proximity to the parent might moderate the association. Method: Data were drawn from five waves of the Korean Longitudinal Study of Aging(2006-2014). The analytic sample consisted of 7,359 parents aged 45 or older who had at least one non-coresidential adult child aged 19 or older. The analyses were conducted by estimating a series of fixed effects models while adjusting for the nested structure of the data. Results: The results showed that first, a closer distance between an adult child and the parent was generally associated with the parent experiencing a decrease in depressive symptoms. Yet, the mental health benefit was smaller for parents aged 65 years or older whose closest living adult child was a son. Second, a closer distance was observed to affect chronic illness only among middle-aged parents (aged 45 to 64). When the closest living adult child was a daughter, the middle-aged parent experienced deterioration in their chronic illness. On the other hand, the opposite pattern was observed when the closest living adult child was a son. Conclusions: The parental age and gender of the adult child in closest proximity to the parent might have varying effects on parents' health. A closer distance between an adult child and their parent has a positive impact on the mental health of the parent as a whole, whereas the effect of living closer was mixed in relation to the parental physical health.

• Structural Engineering and Mechanics
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• v.77 no.2
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• pp.179-196
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• 2021

Experimental investigations on the seismic behaviors of the PVC-FRP Confined Reinforced Concrete (PFCRC) columns under low cyclic loading are carried out and two variable parameters including CFRP strips spacing and axial compression ratio are considered. The PFCRC column finally fails by bending and is characterized by the crushing of concrete and yielding of the longitudinal reinforcement, and the column with a high axial compression ratio is also accompanied by the cracking of the PVC tube and the fracture of CFRP strips. The hysteretic curves and skeleton curves of the columns are obtained from the experimental data. With the increase of axial compression ratio, the stiffness degradation rate accelerates and the ductility decreases. With the decrease of CFRP strips spacing, the unloading sections of the skeleton curves become steep and the ductility reduces significantly. On the basis of fiber model method, a numerical analysis approach for predicting the skeleton curves of the PFCRC columns is developed. Additionally, a simplified skeleton curve including the elastic stage, strengthening stage and unloading stage is suggested depending on the geometric drawing method. Moreover, the loading and unloading rules of the PFCRC columns are revealed by analyzing the features of the skeleton curves. The quantitative expressions that are used to predict the unloading stiffness of the specimens in each stage are proposed. Eventually, an analytical model for the PFCRC columns under low cyclic loading is established and it agrees well with test data.

• Journal of Korea Water Resources Association
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• v.53 no.12
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• pp.1097-1107
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• 2020

A methodology has been proposed to understand the spatiotemporal changes of the river topography through the longitudinal change of the geometric characteristics of the cross-sections and the properties related thereto. Three-dimensional spatial information of the riverbed was obtained through the detailed bathymetry survey using an acoustic echo sounder for the reach from Gumi Weir to Chilgok Weir in the Nakdong river. Geometric informations for the reference sections were extracted using the acquired bathymetry survey data. By comparing the geometric properties for the reference sections, it was possible to catch the topographic characteristics and its changes over a reach of the channel. Through comparison with past survey data, it was also possible to quantitatively grasp the amount of change in cross-sectional area and volumetric change of riverbed. It is expected that a quantitative evaluation of river topography changes will be possible by applying the method proposed in this study.

• Journal of Korean Clinical Nursing Research
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• v.27 no.1
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• pp.98-108
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• 2021

Purpose: This study was conducted to identify the factors influencing the posttraumatic growth (PTG) in patients with lung cancer and to provide basic data for nursing intervention development to improve PTG and adaptation. Methods: The study included 126 non-small cell lung cancer patients initially diagnosed at the Lung Cancer Center, C University Hospital in S city, Gyeonggi-do. Patients were asked to complete a questionnaire consisting of demographic characteristics, disease characteristics, posttraumatic growth, cancer coping, social support, and resilience. Data were analyzed using t-tests, ANOVA, and Pearson's correlation and multiple regression analysis. Results: The mean score for PTG in lung cancer patients was 56.39, cancer coping was 61.31, social support was 61.09, and resilience was 92.77. Significant positive correlations were found for PTG and cancer coping (r=.75, p<.001), social support (r=.52, p<.001) and resilience (r=.63, p<.001). Factors contributing to PTG of lung cancer patients were cancer coping (β=.53 p<.001), perceived health status(β=.20, p=.002), resilience (β=.21, p=.010) and importance of religion (β=.15, p=.013). This model explained about 64.0% of variances of PTG (F=29.58, p<.001). Conclusion: It is necessary to develop new nursing intervention programs to improve PTG for patients with lung cancer based on strategies to enhance coping and resilience to recovery. Longitudinal studies examining temporal changes in PTG among patients with lung cancer are suggested for future studies in this regard.

• The Journal of the Korea Contents Association
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• v.21 no.8
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• pp.662-674
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• 2021

Metabolic syndrome is closely associated with cardiovascular disease, there is increasing attentions in prevention of metabolic syndrome through prediction. The aim of this study was to systematically review the literature by collecting, analyzing, and synthesizing articles of predicting metabolic syndrome in Koreans. For systemic review, data search was conducted on Global journals Pubmed, WoS and domestic journals DBPia, KISS published in 2011-2020 year. Three keyword 'Metabolic syndrome', 'predict', and 'korea' were used for searching under AND condition. Total 560 articles were searched and the final 22 articles were selected according to the data selection criteria. The most useful variable was WHtR(AUC=0.897), most frequently used analysis method was logistic regression(63.6%), and most accurate analysis method was XGBOOST(AUC=0.879) for predicting metabolic syndrome. Prediction accuracy was slightly improved when sasang constitution types was used. Based on the results of this study, it is believed that various large-scale longitudinal studies for the prediction and management of the Metabolic syndrome in Korean should be followed in the future.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.4
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• pp.510-518
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• 2022

The diagnostic evaluation conducted at the national level is very important to detect underachievers in school early. This study used an artificial intelligence method to find the characteristics of underachievers that affect learning development for middle school students. In this study an artificial intelligence model was constructed and analyzed to determine whether the Busan Education Longitudinal Data in 2020 by entering data from the first year of middle school in 2019. A predictive model was developed to predict basic middle school Korean, English, and mathematics education with machine learning algorithms, and it was confirmed that the accuracy was 78%, 82%, and 83%, respectively, in the prediction for the next school year. In addition, by drawing an achievement prediction decision tree for each middle school subject we are analyzing the process of prediction. Finally, we examined what characteristics affect achievement prediction.