• Economic and Environmental Geology
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• v.2 no.4
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• pp.1-21
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• 1969

The Sin po fluorite deposit is of a fissure vein type which strikes $N75^{\circ}E$, dips $80^{\circ}SE$, and is embedded in the pre-Cambrian crystalline schist. The vein is 1 meter in average in thickness, about 800 meters in length and nearly 400 meters in depth. Narrow veins of crustified fluorites and agatic quartz are discontinuously embedded in the quartz gangue. Two-phase fluid inclusions, which are available for the homogenization method by using the Heating Stage Microscope 350, are found in the fluorite crystals. Most of the fluid inclusions are primary in origin and mainly composed of liquid phase associated with minor gas phase. They are tetrahedral, rounded-tubular, wedge shaped, rectangulartrapezoid, and irregular in shape. The maximum diameter of inclusions is 0.5mm and the minimum, 0.03mm, ranging from 0.2mm to 0.08mm in an average. The homogenization temperatures obtained from the test are $135-147^{\circ}C$, $125-138^{\circ}C$, $121-137^{\circ}C$, $116-133^{\circ}C$ and $106-128^{\circ}C$ in greenish, bluish, violet, light grayish blue, colorless and pinkish fluorites respectively. The range of formation temperatures of fluorites is $106-147^{\circ}C$. Therefore, the fluorite deposit of Sinpo Mine is considered to be of low temperature hydrothermal origin. The isothermal lines were drawn on the longitudinal section of the vein from the data of homogenization test. According to the results, the central and lower parts of the ore shoot in the west ore body show the higher temperatures of $130-138^{\circ}C$ and the peripheral and upper parts of it show the lower temperatures of $108-128^{\circ}C$. It seems that the isothermal trend roughly coinside with the pitch of the ore shoot.

• Journal of Family Resource Management and Policy Review
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• v.16 no.1
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• pp.41-66
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• 2012

Recently, Korean baby boomers, which make up approximately 15% of the total population, have begun to retire. Their economic well being is one of Korea's most important social issues. The purpose of this study was to compare the economic structure of baby boomers' households with that of the prior generation, as well as to analyze the determinants of economic satisfaction from the perspective of "work" and "child educational burden." In addition, group comparisons were made regarding economic resource allocation between baby boomers and the prior generation and within baby boomers of different work and child educational burden statuses. Data from the 2nd wave of the Korean Longitudinal Study of Ageing (KLoSA), including baby boomers and the generation prior to the baby boomers, were used. The major findings were as follows. First, the baby boomers had a different economic structure, level of economic satisfaction, and economic resource allocation when compared to the prior generation. The economic structure of baby boomers in terms of income, expenditure, savings and assets, debts, and trust in policies significantly differed from their counterparts. Second, the determinants of economic satisfaction and the propensity of resource allocation were different depending on whether they worked or had a child educational burden, respectively. Based on these empirical results, policy implications for the future economic well being of baby boomers were provided.

• Journal of the Korea Society of Computer and Information
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• v.25 no.9
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• pp.159-166
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• 2020

The purpose of this research is to suggest some practical and policy implications for improving adolescent's self-esteem through analyzing longitudinally the effects of parental attitude, peer relationship, student-teacher relationship, school learning activity, life-goal on adolescent's self-esteem by using latent growth curve model. Analytical data was obtained from the KYCPS. The analytical results showed that the change model of adolescent's self_esteem turned out to be a leaner model in which the change rate and intercept were significant. Second, time dependent variables influence on adolescent's self_ esteem meaningfully. Third, time dependent variables influence on adolescent's self_ esteem changes significantly. This study proposed some policy implications basing on these findings.

• Journal of Korean Academy of Nursing
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• v.35 no.2
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• pp.283-291
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• 2005

Purpose: The purpose of this study was to explore the levels of depression experienced by clients (N=152) with Type 2 Diabetes Mellitus(DM), and to compare the levels of self care activity, metabolic control and cardiovascular risk factors between depressed and non-depressed clients. Method: Participants aged 50 and above were conveniently recruited in B city. The levels of depression, self-care activity, metabolic control of glucose and lipids, and cardiovascular risk factors of the participants were measured by using questionnaires and blood tests from November, 2003 to June, 2004. Data was analyzed with descriptive statistics, Pearson correlation, Spearman rho and t-test using the SPSS WIN 10.0 program. Result: The prevalence of depression(CES-D=16) among the participants was $44.1\%$. The levels of self-care activities(p=.012), glucose(p=.019), total cholesterol(p=.022), LDL(.007) and cardiovascular risk factors(p=.012) were significantly higher in the depressed group than those in the non-depressed group. Conclusion: Based on the findings, we concluded that many DM patients experience depression and the depression of type 2 DM clients is significantly related with self care activities, diabetic control, and cardiovascular complications. However, this study did not address causality among these variables. Therefore, further research, such as a longitudinal cohort study, is needed to identify causality among these variables.

• Journal of Korean Academy of Nursing
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• v.44 no.6
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• pp.649-659
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• 2014

Purpose: The purpose of this study was to develop and evaluate a school-based peer leader centered smoking prevention program. Methods: Non-equivalent control group with a pre/post-test design was used. Students (n=174) in two boys' junior high schools located in D city, Korea participated with 85 being selected for the experimental group and 89 for the control group. Five sessions were given to the experimental group and a 50 minute lecture to the control group. Knowledge, attitude, nonsmoking intention, and nonsmoking efficacy were measured for the both experimental and control group at two weeks before the program and one month after the program was completed. Data were analyzed using ${\chi}^2$-test, Fisher's exact test, independent t-test and paired t-test with the SPSS 21.0 program. Results: The experimental group showed higher overall knowledge, negative attitude toward smoking, and higher non-smoking intention and efficacy. After receiving the school based peer leader centered smoking prevention program scores for attitude toward smoking and nonsmoking efficacy increased in the experimental group were higher than in the control group. Conclusion: The school-based peer leader centered smoking prevention program needs longitudinal evaluation, but from this study, there is an indication that this program can be used with junior high school students and effectively change students' attitude toward smoking and promote nonsmoking efficacy.

• Journal of Digital Convergence
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• v.13 no.8
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• pp.161-168
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• 2015

Given social problems of social network service (SNS) addiction, it is critical to understand user's formation mechanism of SNS addiction. Since a number of studies have demonstrated the negative outcomes of excessive SNS use, the researchers examined important antecedents of SNS addiction as SNS habit that is considered as a key driver of SNS addiction. Moreover, the effects of self-expression, network management, and information search on SNS addition formation were investigated. The proposed theoretical model was empirically tested by using longitudinal survey data collected from 206 Facebook users. The analysis results indicate that SNS habit plays an important role in forming SNS addiction. Further, self-expression, network management, and information search influence SNS addiction through SNS habit. The analysis results offer some in-depth perspectives to SNS providers and government that establish policies or digital convergence strategies to induce healthy SNS use.

• Structural Engineering and Mechanics
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• v.63 no.6
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• pp.713-723
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• 2017

As a new type of ballastless track, longitudinal continuous slab track (CST) has been widely used in China. It can partly isolate the interaction between the ballastless track and the bridge and thus the rail expansion device would be unnecessary. Compared with the traditional track, CST is composed of multi layers of continuous structures and various connecting components. In order to investigate the performance of CST on a long-span bridge, the spatial finite element model considering each layer of the CST structure, connecting components, bridge, and subgrade is established and verified according to the theory of beam-rail interaction. The nonlinear resistance of materials between multilayer track structures is measured by experiments, while the temperature gradients of the bridge and CST are based on the long-term measured data. This study compares the force distribution rules of ballasted track and CST as respectively applied to a long span bridge. The effects of different damage conditions on CST structures are also discussed. The results show that the additional rail stress is small and the CST structure has a high safety factor under the measured temperature load. The rail expansion device can be cancelled when CST is adopted on the long span bridge. Beam end rotation caused by temperature gradient and vertical load will have a significant effect on the rail stress of CST. The additional flexure stress should be considered with the additional expansion stress simultaneously when the rail stress of CST requires to be checked. Both the maximum sliding friction coefficient of sliding layer and cracking condition of concrete plate should be considered to decide the arrangement of connecting components and the ultimate expansion span of the bridge when adopting CST.

• Journal of Periodontal and Implant Science
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• v.47 no.2
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• pp.96-105
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• 2017

Purpose: The National Health Insurance Service-National Sample Cohort and medical checkup data from 2002 to 2013 were used to evaluate the association between periodontal surgery for the treatment of periodontitis (PSTP) and vasculogenic erectile dysfunction (VED). Methods: Bivariate and multivariate logistic regression analyses were applied to a longitudinal retrospective database to assess the association between PSTP and VED while adjusting for the potential confounding effects of sociodemographic factors (age, household income, insurance status, health status, residence area, and smoking status) and comorbidities (diabetes mellitus, angina pectoris, cerebral infarction, and myocardial infarction). Results: Among the 7,148 PSTP within the 268,296 recruited subjects, the overall prevalence of VED in PSTP was 1.43% (n=102). The bivariate analysis showed that VED was significantly related to PSTP (odds ratio [OR], 1.99; 95% confidence interval [CI], 1.38-2.06; P<0.001), and this was confirmed in the multivariate analysis after adjusting for sociodemographic factors and comorbidities (OR, 1.29; 95% CI, 1.06-1.58; P=0.002). Conclusions: Subjects with a history of periodontal flap surgery had a significantly higher risk of VED, after adjusting for potential confounding factors. Further studies are required to identify the key mechanisms underlying the association between severe periodontal disease and VED.

• Journal of the Korean Society for Marine Environment & Energy
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• v.20 no.2
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• pp.63-75
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• 2017

In offshore environment, an accurate estimation of a wave-structure interaction has been an important issue for safe and cost effective design of fixed and floating offshore structures exposed to a harsh environment. In this study, a wave-structure interaction around a circular column was investigated with regular waves. To simulate 3D two-phase flow, open source computational fluid dynamics libraries, called OpenFOAM, were used. Wave generation and absorption in the wave tank were activated by the relaxation method, which implemented in a source term. To validate the numerical methods, generated Stokes 2nd-order wave profiles were compared with the analytic solution with deep water condition. From the validation test, grid longitudinal and vertical sizes for wave length and amplitude were selected. The simulated wave run-up and wave loads on the circular column were studied and compared with existing experimental data.

• Journal of Families and Better Life
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• v.34 no.4
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• pp.1-19
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• 2016

The present study aimed at investigating the relations between the amount of child care experienced in the first three years of life and socioemotional development of children at age 4 indicated by problem behaviors and peer competence. Using the longitudinal data of the Panel Study of Korean Children(PSKC), the information of 1,699 children were analyzed. The results indicated that any child care experience, hours in child care, full-time child care and early entry to child care were significantly related to children's externalizing behavior problem and play disruption at age 4. Some significant relations were detected between child care experience and better peer competence as well. Interestingly, the patterns of relations were different for boys and girls. Being in child care, a greater amount of child care and early entry to child care tended to be related to externalizing problem behaviors of boys and whereas they were more related to peer competence of girls indicated by play interaction, play disruption and play disconnection. Child care hours at age 3 were relative stronger predictors of children's development compared to those at age 1 or at age 2. The findings imply that the amount of child care during the first 3 years of life does not have strong harmful effects on preschoolers' socioemotional development and that there are differences in the effects of child care on boys and girls.