• Journal of Families and Better Life
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• v.34 no.1
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• pp.1-12
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• 2016

The purpose of this research is to find out the differences of participation in common activities and life satisfaction of Swedish senior cohousing residents between the years of 2001 and 2010 by conducting a longitudinal study. The same questionnaire were surveyed nationwide to 186 residents of 8 Senior $G{\aa}rden$ cohousings in 2001 and 127 residents of 4 +40 cohousings in 2010, resulting in total 313 respondents' data. The results show that the +40 cohousing respondents are more likely than Senior $G{\aa}rden$ cohousing respondents to participate in all common activities, especially common meals and common coffee meetings. However, the subjective evaluation of the quantity as well as the contents of participating in common activities does not statistically differ in the two groups and life satisfaction is similarly high with a few differences. The +40 cohousing respondents are less likely to stay at and more likely to move into age-mixed cohousing if they have a chance to move when compared to their Senior $G{\aa}rden$ cohousing counterparts. The result of this research reveals that the general characteristics of senior cohousing residents have been changed and they have become more likely to be active participants of various common activities and have high life satisfaction.

• Journal of the Korean Society for Railway
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• v.9 no.1 s.32
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• pp.118-124
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• 2006

SThe rigidities of bridge substructures are the important data in the rail-bridge interaction analysis in Korean High -Speed Railway. This experimental study is being performed because of followings. 1) More correct longitudinal stiffness of the structure including substructure should be considered in the calculation of stresses in rails. 2) There are many uncertainties in the design and construction of the piers and foundations. 3) Actual guideline for the rigidities of piers and foundations in the design is necessary. 4) Measurement on the rigidity of pier according to the types of piers, foundations and soil-conditions is needed. Curve for estimating the total rigidity of substructure will be obtained through this and further experimental studies. It may be used in the analysis of Korean High-Speed Railway bridge and then, longitudinal stresses in the rails can be estimated more accurately. One pair of piers, which consist of pot-bearing for fixed support and pad-bearing for movable support, are loaded by steel frame devices with steel wire ropes and hydraulic jack. The responses which are measured at each loading stages in those field tests are displacements and tilted angles on the top and bottom of piers. This study is being performed testing and analysis about several piers in the construction field.

• Smart Structures and Systems
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• v.17 no.6
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• pp.1107-1127
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• 2016

Studies on dynamic characteristics of the hanger vibration using field monitoring data are important for the design and evaluation of high-speed railway truss arch bridges. This paper presents an analysis of the hanger's dynamic displacement responses based on field monitoring of Dashengguan Yangtze River Bridge, which is a high-speed railway truss arch bridge with the longest span throughout the world. The three vibration parameters, i.e., dynamic displacement amplitude, dynamic load factor and vibration amplitude, are selected to investigate the hanger's vibration characteristics in each railway load case including the probability statistical characteristics and coupled vibration characteristics. The influences of carriageway and carriage number on the hanger's vibration characteristics are further investigated. The results indicate that: (1) All the eight railway load cases can be successfully identified according to the relationship of responses from strain sensors and accelerometers in the structural health monitoring system. (2) The hanger's three vibration parameters in each load case in the longitudinal and transverse directions have obvious probabilistic characteristics. However, they fall into different distribution functions. (3) There is good correlation between the hanger's longitudinal/transverse dynamic displacement and the main girder's transverse dynamic displacement in each load case, and their relationships are shown in the hysteresis curves. (4) Influences of the carriageway and carriage number on the hanger's three parameters are different in both longitudinal and transverse directions; while the influence on any of the three parameters presents an obvious statistical trend. The present paper lays a good foundation for the further analysis of train-induced hanger vibration and control.

• Bulletin of the Society of Naval Architects of Korea
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• v.12 no.2
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• pp.59-66
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• 1975

Recently, as the dimensions of energy carriers increase, especially in draft, a reliable prediction of the ship motions at finite depths of water becomes necessary. The purpose of this paper is to probe the effect of finite water depth on the hydrodynamic forces and ship motions, particularly heave and pitch, in longitudinal regular head waves, by comparing the experimental value of Freakes and Keay with the author's theoretical value obtained by applying the modified strip theory to the Mariner class ship. It is confirmed that generally the hydrodynamic coefficients in the equations of motion increase with decreasing water depth, and the wave exciting forces and moments decrease with decreasing water depth. Amplitudes of heave and pitch in longitudinal regular head waves decrease as the water depth in the range where the length of the incident wave is comparatively long. The effects of Froude Number on the hydrodynamic coefficients increase with decreasing water depth and is more noticeable in the case of heave than pitch. In heave, generally the discrepancy between the experimental value and the theoretical value is relatively small in the case of $F_n=O$, but it is very large in the case of $F_n=0.2$. It is considered that the trend stems from the ignorance of the three dimensional effect and the other effects due to shallowness of water on the hydrodynamic coefficients in the theoretical calculation. An extension of methods for calculating the two dimensional hydrodynamic forces to included the effect of forward speed should be recommended. It is required that more experimental works in finite water depths will be carried out for correlation studies between the theoretical calculation, according tp modified strip theory, and model experiments.

• Journal of Preventive Medicine and Public Health
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• v.43 no.3
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• pp.193-204
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• 2010

Objectives: The objective of this study was to analyze the causal relationship between smoking and depression using longitudinal data. Methods: Two waves of the Korea Welfare Panel collected in 2006 and 2007 were used. The sample consisted of 14 426 in 2006 and 13 052 in 2007 who were aged 20 and older. Smoking was measured by smoking amount (none/$\geq$ two packs). Depression was defined when the summated CESD (center for epidemiological studies depression)-11 score was greater than or equal to 16. The causal relationship between smoking and depression was tested using logistic regression. In order to test the causal effect of smoking on depression, depression at year 2 was regressed on smoking status at year 1 only using the sample without depression at year 1. Likewise, smoking status at year 2 was regressed on depression at year 1 only using those who were not smoking at year 1 in order to test the causal effect of depression on smoking. The statistical package used was Stata 10.0. Sampling weights were applied to obtain the population estimation. Results: The logistic regression testing for the causal relationship between smoking and depression showed that smoking at year 1 was significantly related to depression at year 2. Smoking amounts associated with depression were different among age groups. On the other hand, the results from the logistic regression testing for the opposite direction of the relationship between smoking and depression found no significant association regardless of age group. Conclusions: The study results showed some evidence that smoking caused depression but not the other way around.

• Journal of Korean Academy of Psychiatric and Mental Health Nursing
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• v.27 no.4
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• pp.321-331
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• 2018

Purpose: The purpose of this study was to identify factors influencing decreasing depressive mood of married women with depression. Methods: Data that integrate the Korean longitudinal survey of women and families in 2014 and 2016 were used. Subjects for this study were 974 people who participated in the fifth survey in 2014 and the sixth survey in 2016, and married women were included in the depression group in the fifth survey. The data was analyzed with $x^2$ test, t-test, and logistic multiple regression analysis using the SPSS 23.0 program. Results: The decreased-depression group's depression decreased from 11.78 points in the fifth survey to 6.31 points in the sixth survey. This study showed that main factors such as age (OR=0.96, p=.002), educational level (OR=0.54, p=.007), economical status (OR=0.62, p=.037), satisfaction with marriage life (OR=1.15, p<.001), use of medical services (OR=1.65, p=.002), and physical activity (OR=1.08, p=.019) help decrease married women's depression. Conclusion: This study findings indicate a need to develop the strategies to increase satisfaction for marriage life and physical activity and to enhance health promotion to decrease depression among depressed married women.

• Journal of Korean Academy of Nursing
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• v.49 no.1
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• pp.69-79
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• 2019

Purpose: This study aimed to identify the directionality of the causal relationship and interaction between depression and amount of smoking over time in hardcore smokers using longitudinal descriptive analysis. Methods: Secondary data from the Korean Welfare Panel Study were analyzed using autoregressive cross-lagged modeling. Participants included 342 hardcore smokers who participated in the 8th to 11th waves of the panel study. Results: Analyses revealed that change(s) in depression levels according to time had a significant positive relationship with the total amount of smoking per day (${\beta}=.29$, ${\beta}=.19$, ${\beta}=.17$, p<.001), while change(s) in total amount of smoking per day according to time had a significant positive relationship with depression (${\beta}=.43$, ${\beta}=.50$, ${\beta}=.38$, p<.001). Analysis of the cross-lagged effect between depression and total amount of smoking per day showed that depression at one time point had a significantly positive relationship with the total amount of smoking per day at the next time point (${\beta}=.14$, ${\beta}=.13$, ${\beta}=.13$, p=.021), and that the total amount of smoking per day at one time point had a significant positive relationship with depression at the next time point (${\beta}=.04$, ${\beta}=.04$, ${\beta}=.03$, p=.044). Conclusion: The findings in the present study confirmed a cross-interaction between depression and total amount of smoking per day in hardcore smokers. The present findings could be used to develop appropriate smoking-related interventions.

• Steel and Composite Structures
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• v.39 no.5
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• pp.583-598
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• 2021

The composite steel reinforced concrete (SRC) columns have been widely used in Structural Engineering due to their good performances. Many studies have been done on the SRC columns' performances, but they focused on the ordinary types with conventional configurations and materials. In this study, nine new types of steel reinforced lightweight aggregate concrete (SRLAC) short columns with cross-shaped (+shaped and X-shaped) steel section were tested under monotonically axial compressive load; the studied parameters included steel section ratio, steel section configuration, ties spacing, lightweight aggregate concrete (LWAC) strength, and longitudinal bars ratio. From the results, it could be found that the specimens with larger ties ratio, concrete strength, longitudinal bars ratio, and steel section ratio achieved great strength and stiffness due to the excellent interaction between the concrete and steel. The well-confined concrete core could strengthen the steel section. The ductility and toughness of the specimens were influenced by the LWAC strength, steel section ratio, and longitudinal bars ratio; in addition, larger ties ratio with smaller LWAC strength led to better ductility and toughness. The load transfer between concrete and steel section largely depends on the LWAC strength, and the ultimate strength of the new types of SRLAC short columns could be approximately predicted, referring to the codes' formulas of ordinary types of steel reinforced concrete (SRC) columns. Among the used codes, the BS-5400-05 led to the most conservative results.

• Journal of Preventive Medicine and Public Health
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• v.54 no.6
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• pp.395-403
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• 2021

Objectives: Previous studies have shown that participation in social activities (SA) can prevent cognitive decline (CD) and that living arrangements (LA) can affect cognitive function. This study aimed to evaluate the effects of SA and LA on CD, as well as their interactions, using longitudinal data. Methods: Data were used from the 2006-2018 Korean Longitudinal Study for Aging, which followed 10 254 adults older than 45 years over a 12-year period. CD was defined as a ≥4-point score decrease in the Mini-Mental Status Exam over 2 years. We developed an extended Cox proportional hazards model for time-dependent covariates to estimate the hazard ratio (HR) of CD in 4 groups: (1) socially active and living with others, (2) socially active and living alone, (3) socially inactive and living with others (SILO), and (4) socially inactive and living alone (SILA). The model was stratified by gender and adjusted for important confounders. Results: The HR of CD was significantly higher in the SILO group in men (HR,1.36; 95% confidence interval [CI], 1.08 to 1.78) and in the SILA group in women (HR, 1.72; 95% CI, 1.08 to 2.75). However, the interaction term for gender was not significant. Conclusions: Among socially inactive elderly adults, the HR of CD was elevated in men who lived with others and in women who lived alone, although the interaction term for gender was not significant. Socially inactive men who live with others and socially inactive women who live alone are particularly encouraged to participate in SA to prevent CD.

• The Journal of the Convergence on Culture Technology
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• v.8 no.2
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• pp.315-319
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• 2022

This study investigates longitudinal writing development in terms of syntactic complexity using linear mixed effects (LME) model. This study employs essays written by four case study participants. Participants voluntarily wrote essays outside of the classroom and submitted the first and second drafts, after reflecting on the automated writing evaluation feedback (i.e., Criterion) every month over one year. A total of 48 first drafts were analyzed and syntactic complexity features were selected from Syntactic Complexity Analyzer. Results of LME showed that there was a significant positive linear relationship between time and mean length of T-unit and also between time and the ratio of dependent clauses to independent clauses, indicating that case study participants wrote longer T-units and also a higher proportion of dependent clauses over one year.