• Journal of Astronomy and Space Sciences
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• v.36 no.2
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• pp.75-86
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• 2019

UV Psc is a typical RS CVn type system undergoing dynamic chromosphere activity. We performed photometric observations of the system in 2015 and secured new BVR light curves showing well-defined photometric waves. In this paper, we analyzed the light curves using Wilson-Devinney binary code and investigated the orbital period of the system. The combination of our light curve synthesis with the spectroscopic solution developed by previous investigators yielded the absolute parameters as: $M_1=1.104{\pm}0.042M_{\odot}$, $R_1=1.165{\pm}0.025R_{\odot}$, and $L_1=1.361{\pm} 0.041L_{\odot}$ for the primary star, and $M_2=0.809{\pm}0.082M_{\odot}$, $R_2=0.858{\pm}0.018R_{\odot}$, and $L_2=0.339 {\pm}0.010L_{\odot}$ for the secondary star. The eclipse timing diagram for accurate CCD and photoelectric timings showed that the orbital period may vary either in a downward parabolic manner or a quasi-sinusoidal pattern. If the latter is adopted as a probable pattern for the period change, a more plausible account for the cyclic variation may be the light time effect caused by a circumbinary object rather than an Applegate-mechanism occurring via variable surface magnetic field strengths.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.48 no.6
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• pp.348-355
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• 2022

Objectives: To compare the vital sign stability and cost of two commonly used sedatives, midazolam (MDZ) and dexmedetomidine (DEX). Patients and Methods: This retrospective study targeted patients who underwent mandibular third molar extractions under intravenous sedation using MDZ or DEX. The predictor variable was the type of sedative used. The primary outcome variables were vital signs (heart rate and blood pressure), vital sign outliers, and cost of the sedatives. A vital sign outlier was defined as a 30% or more change in vital signs during sedation; the fewer changes, the higher the vital sign stability. The secondary outcome variables included the observer's assessment of alertness/sedation scale, level of amnesia, patient satisfaction, and bispectral index score. Covariates were sex, age, body mass index, sleeping time, dental anxiety score, and Pederson scale. Descriptive statistics were computed including propensity score matching (PSM). The P-value was set at 0.05. Results: The study enrolled 185 patients, 103 in the MDZ group and 82 in the DEX group. Based on the data after PSM, the two samples had similar baseline covariates. The sedative effect of both agents was satisfactory. Heart rate outliers were more common with MDZ than with DEX (49.3% vs 22.7%, P=0.001). Heart rate was higher with MDZ (P=0.000). The cost was higher for DEX than for MDZ (29.27±0.00 USD vs 0.37±0.04 USD, P=0.000). Conclusion: DEX showed more vital sign stability, while MDZ was more economical. These results could be used as a reference to guide clinicians during sedative selection.

• Journal of Korean Academy of Nursing
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• v.46 no.3
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• pp.454-462
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• 2016

Purpose: Posttraumatic growth (PTG) is defined as 'positive psychological change experienced as a result of a struggle with highly challenging life circumstances'. The purpose of this study was to identify the level of PTG and its correlates in Korean patients with breast cancer. Methods: A sample of 120 participants was recruited from outpatients, who had successfully completed primary treatment of breast cancer at a university hospital., Data were collected from June to December, 2014 using Posttraumatic Growth Inventory, Illness Intrusiveness Rating Scale, Cancer Coping Questionnaire, Revised Life Orientation Test and The Multidimensional Scale of Perceived Social Support. Results: Total score for the PTG was $79.18{\pm}17.54$ in patients surviving breast cancer. Bivariate analyses indicated that PTG was positively associated with having a religion, perceived social support, greater optimism, cancer coping, and illness intrusiveness. Results of the regression analysis showed that cancer coping (${\beta}=.29$, p=.001), optimism (${\beta}=0.28$, p=.001) and illness intrusiveness (${\beta}=0.17$, p=.037) were statistically significant in patients' PTG. Conclusion: The research findings show that the variables of cancer coping, optimism and illness intrusiveness significantly explain PTG and these psychological variables can be used to provide improvement in PTG for patients with breast cancer.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.20 no.3
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• pp.1-18
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• 2017

This study constructed a high-resolution bioclimatic classification map of South Korea which classifies land into homogeneous zones by similar environment properties using advanced statistical techniques compared to existing ecological area classification studies. The climate data provided by WorldClim(1960-1990) were used to generate 27 bioclimatic variables affecting biological habitats, and key environmental variables were derived from Correlation Analysis and Principal Component Analysis. Clustering Analysis was performed using the ISODATA method to construct a 30'(~1km) resolution bioclimatic classification map. South Korea was divided into 21 regions and the results of classification were verified by correlation analysis with the Gross Primary Production(GPP), Actual Vegetation map made by the Ministry of Environment. Each zones' were described and named by its environmental characteristics and major vegetation distribution. This study could provide useful spatial frameworks to support ecosystem research, monitoring and policy decisions.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.32 no.3
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• pp.205-214
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• 2024

The aircraft delay rate has increased nearly three times in 2023 due to change in Korea policy of delay criteria. One of the primary causes of delays in domestic flights is related to reactionary delays, with Turnaround Time being a key factor. To mitigate reactionary delays and reduce aircraft delays, it is essential to establish an appropriate Turnaround Time and integrate it into flight schedules. This study aims to analyze the appropriate Turnaround Time for aircraft operating at Gimpo, Gimhae, and Jeju International Airports, which handle a high frequency of domestic flights. The research applies air traffic simulation, using variables such as current flight schedules, actual flight times, Turnaround Time, and flight routes to simulate actual conditions. Based on this analysis, the study seeks to identify the fitting Turnaround Time across various scenarios. The findings are expected to address reactionary delays and help reduce overall delay rates in domestic flights.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.81-87
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• 2017

This paper describes the dynamic behavior and enhancement of Korean high-speed trains. The tail vibration reduction method of the yaw damper installation method change, which was derived from previous research, was applied to the running test of high-speed train. In addition, the vibration reduction method for the entire vehicle was derived by a numerical method and its effect was confirmed by a running test. The improved design was applied to the double-deck high-speed train coaches and the commissioning proceeded without problems in dynamic behavior. Sensitivity analysis of the suspension parameters affecting the critical speed of Korean next-generation high-speed trains was performed and four design variables that greatly affected the critical speed were derived. These were in the order of the primary elastic joint x-directional stiffness, the secondary yaw damper series stiffness, the secondary lateral damper damping coefficient, and the carbody damper damping coefficient. By optimizing the design variables, the suspension parameter that improves the critical speed by 23.3% can be used in the commercial designs of Korean next-generation high-speed trains.

• Journal of Nutrition and Health
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• v.29 no.5
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• pp.547-558
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• 1996

A rapid increase in urbanization and industrialization brings about a change in economic status which results in considerable changes in lifestyle including food habits and disease and mortality patterns. The purpose of the present study was to investigate recent food habit changes if any, reasons for food habit change, current food consumption patterns, and breakfast practices among urban adults with middle and upper income levels. Three hundred men and women, aged 20-60 years, were randomly selected and interviewed individually by trained interviewers. Among the twenty food groups studied, subjects reported that, compared to two years ago, they are now eating more fast foods, meats, fish, vegetables and fruits, and less rice, noodles, pastries, and salt. The changes in fast foods, fruits, and rice consumption patterns varied significantly between age, sex, income level, and BMI groups. The two most primary reasons for food habit changes were 'for my own health' and 'for my family's health', which shows that health seems to be the major concern in changing food habits. Among meals, the breakfast meal was rated as the most important one, and was not affected by the sociodemographic variables. However, the average rate of skipping breakfast was found to be as high as 33% with a greater rate in younger age groups. The rats of breakfast skipping was found to vary between different income, education, and BMI groups. Among the subjects who eat breakfast meals daily, a traditional Korean breakfast of rice and soup was found to be still a predominant choice, although younger age groups, upper income groups, and people with more education choice, although younger age groups, upper income groups, and people with more education tended to eat a western-style breakfast more frequently. These findings are applicable at the planning and implementation stages of various nutritional improvement projects as a part of the National health Promotion Law.

• Research in Community and Public Health Nursing
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• v.6 no.2
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• pp.234-249
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• 1995

Essential hypertension, one of the leading primary cause of death in Korea, is a typical chronic disease requiring adequate and continuous management. Though these hypertensives need to maintain desirable health practice by themselves for their life time, many previous studies indicated that most of the essential hypertensives have no specific symptoms and thus, reluctant to follow appropriate medical regimens causing the condition further aggravated and complicated. Thus the comprehensive self-regulation program was conducted as a nursing intervention on the promotion self-care 'performance and improvement in physical parameters of hypertensives. For this purpose, a one group quasi -experimental research with pre and post test design was used. And the whole program was carried out from October, 1993 to February, 1994. Self-regulation program was consisted with group education on hypertension and self-care, self-regulation including the blood pressure self-monitoring and recording, recording of daily self-care activities, and encouraging and reinforcing self-efficacy through verbal persuation and enactive attainment. The subjects were asked to measure their own blood pressure by themselves twice per day and to record blood pressure and the daily self-care performance according to the instructions provided during the whole period of 9 weeks. The data was analyzed by experimental stages: the first week, the fifth week, and the ninth week since the experimental imput began. Data were analyzed by the SPSS PC+ program with paired t -test and F-test, and multiple correlation to determine the variables affecting the effect of program. The results were as follows : 1) Subjects in J company were significantly lower diastolic blood pressure than K company after the program (t=2.39, p=.024). Level of cholesterol was significant difference according to position(t=2.23, p=.034), family history (t=-2.66, p=.013), diagnosis duration, and career(t=2.88, p=.055). Perceived self-efficacy was more significantly increased among the group with family history(t=-3.00, p=.013). 2) Before the program, there were significant positive correlation among the variables: internal-LOC and self-efficacy(r=.3952, p=.015), external-LOC and barriers (r=.6515, p=.000), chance-LOC and Barriers(r=.4133, p=.012). However there were significant negative correlation between internal-LOC and barriers (r=-.3236, p=.041, external-LOC and self -efficacy(r=-.3517, p=.028), self-efficacy and barriers(r=-.6654, p=.000). 3) There were significant relationships between changes in self - care performance and self-efficacy at 5th week (r=.5313, p=.001) and changes in self-efficacy at 9th week(r=.4586, p=.005). 4) After the program, internal health locus of control and perceived benefits showed significant correlation(r=.5673, p=.001, but perceived barriers was negative correlation with perceived self-efficacy (t=-4242, p=.01). From the above results, it can be concluded that the self-regulation program is an effective nursing strategy through the change of variables to promote self-care performance of hypertensives and to increase the self-efficacy. Thus this program can be recommended in the management of the hypertensives in workplaces and community settings.

• Journal of Korea Foundry Society
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• v.32 no.6
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• pp.276-283
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• 2012

This study presents the results on the changes of crucible thermal conductivity and inflow of Ar, and constructed the mathematical model about heat transfer into furnace. As process variables, simulation model was designated thermal conductivity of crucible to $0.5W{\cdot}m^{-1}{\cdot}K^{-1}$, $1W{\cdot}m^{-1}{\cdot}K^{-1}$, $2W{\cdot}m^{-1}{\cdot}K^{-1}$, $4W{\cdot}m^{-1}{\cdot}K^{-1}$, and inflow rate of Ar to 15 L/min, 30 L/min, 60 L/min. Initial condition and boundary condition were set respectively in two terms of process. Each initial conditions were set up by the preceding simulation of heat and fluid flow. The primary goal is the application of unidirectional growth of Si ingot using the result. In the result of the change of heat conductivity of crucible, the higher thermal conductivity of crucible shows the shorter solidification time and the bigger temperature difference. And the flow patterns are changed with the inflow rate of Ar. Finally, we found that the lower crucible's thermal conductivity, the better crucible is at polycrystalline Si ingot growth. But in case of Ar inflow, it is hard to say about good condition. This data will be evaluated as useful reference used in allied study or process variable control of production facilities.

• The Journal of the Korean dental association
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• v.55 no.5
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• pp.339-350
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• 2017

The aim of the study was to analyze the distribution of dental filling materials for carious permanent teeth of school children in a city. The study was designed as time-serial study, using the data of the dental survey for children aged 8-, 10- and 12-year children living in Gimhae city. The samples were selected by stratified clusters sampling. The number of surveyed samples in depth-analysis for types of dental filling materials were 567 in 2009 and 331 in 2013, respectively. They had dental restorations on one or more teeth. The changing pattern of used dental filling materials was analyzed between 2009 and 2013. Statistical analysis was conducted according to variables related to dental filling material type; DMFT and DMFS index, number of fissure sealed teeth and surface and surveyed year. Amalgam filling rate decreased from 27.9% in 2009 to 18.8% in 2013, while filling rate of tooth-colored materials increased from 56.1% in 2009 and 68.9% in 2013. Amalgam filling rate was a negative correlation with filling rate of tooth-colored materials or gold and number of fissure sealed teeth and a positive correlation with DMFT index. Filling rate of tooth-colored materials was a negative correlation with filling rate of amalgam or gold and DMFT index and a positive correlation with number of fissure sealed teeth. The light-curing composite resin should be included in the reimbursement range of National Health Insurance to solve an inequity of dental health care services.