• Journal of Korean Society for Atmospheric Environment
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• v.15 no.3
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• pp.257-266
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• 1999

In order to analyze the effect of meteorological elements on ozone concentration, we carried out cross-correlation of the elements with ozone concentraton, and time series analysis on them. As a result, it revealed that temperature, wind speed and humidity are not independent variables with ozone concentrations, and also, solar radiation and mixing height are the major elements that affect them. We developed models for ozone with solar radiation and mixing height as dependent variables to verify the effect of major meteorological elements. The predicted ozone concentration has strong correlation coefficients, So, We could conclude that we can predict ozone concentreation only with solar raidation and mixing height as dependents.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.686-691
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• 2000

Animation technique from the PIV database is particularly emphasized to give macroscopic and Quantitative description of complex flow fields. As an example, an experimental study was carried out investigate the fundamental (low characteristics of the freezer with the domestic refrigerator. Optimized cross correlation identification to obtain velocity vectors is implemented by direct calculation of correlation coefficients. Image intensifier CCD camera to cope with illumination problem is arranged for the accurate PIV measurement of large flow field. As a results, continuous pictures of the spatial distribution of the instantaneous and time-mean velocity distribution are displayed in real-time sense.

• The KSFM Journal of Fluid Machinery
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• v.2 no.1 s.2
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• pp.35-42
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• 1999

The present experimental study is focused on the application of multi-point simultaneous measurement by PIV(Particle Image Velocimetry) to rotor-stater region within centrifugal turbine pump. Six different kinds of rpm(120, 500, 1000, 1500, 2000 and 2500) are selected as experimental condition. Optimized cross correlation identification to obtain velocity vectors is implemented with direct calculation of correlation coefficients. Fine optical setup concerned with PIV performance is arranged for the accurate PIV measurement of high-speed complex flow. The instantaneous and time-mean velocity distribution and velocity profile are represented quantitatively at the rotor and stator region.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.15
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• pp.33-59
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• 1974

A series of experiments were conducted at Crop Experiment Station from 1968 to 1971 to obtain basic information on effects of selection on yield of wheat varieties. Heritability estimates, correlation and path coefficients computed for yield and yield related characters from fixed variety groups-Korean, U.S., and Japan; early and late-$F_2$ and $F_3$ generations were studied. The same estimates for fixed variety groups grown under different fertilizer levels and years were also studied. The results were summarized as follow: 1. Three variety groups classified by their origins as Korea, United States and Japan showed high heritability estimates for heading date, plant height and spike length. The heritability estimates for grain number per spike and 1, 000 grain weight were moderate and those for the number of spikes per plant and grain yield were low. Very low estimates of heritability were obtained for grain number per spike and yield of variety group from the Unites States. 2. High genotypic correlation coefficients between 1, 000 grain weight and yield were obtained for all variety groups originated from Korea, United States and Japan and early variety group, except late variety group. The genotypic correlation coefficients between grain number per spike and yield were also high for all variety groups except variety group originated from the United States. 3. The direct effects of 1, 000 grain weight in terms of path-coefficients to yield were high for all variety groups except late variety group. 4. High genotypic correlation coefficients were obtained between 1, 000 grain weight and yield in $F_2$ from. two crosses. The same degree of genotypic correlation coefficients were obtained between grain number per spike and yield, although slight differences in its magnitude were found depending upon the cross combination. 5. The analysis of path-coefficients in $F_2$ shows that the direct effects of yield components to yield were negligible. 6. The characters that showed high genotypic correlation coefficients with yield in $F_3$ were 1, 000 gnain weight and grain number per spike. These characters showed also high direct effects to yield. 7. No great variations of heritability estimates for heading date, plant height and spike length were obtained for either fertilizer responsive or non responsive variety group due to fertilizer levels applied. 8. Heritability estimates of 1, 000 grain weight in fertilizer responsive group and yield in fertilizer nonresponsive group were high as level of fertilizer increased. 9. Heritability estimates for grain number per spike and 1, 000 grain weight of fertilizer non-responsive-group were higher than those of fertilizer. responsive group. 10. Genotypic corretation coefficients between yield and 1, 000 grain weight in fertilizer responsive group were getting lower as the level of fertilizer increased and those in fertilizer non-responsive group were vice versa. 11. Genotypic correlation coefficient between yield and spike number per plant in fertilizer responsive group was high. However, the genotypic correlation coefficient between yield and spike number per plant in fertilizer non-responsive group was low. 12. The direct effects of 1, 000 grain weight to yield were higher than other yield components either in fertilizer responsive or non-responsive group regardless of levels of fertilizer applied. The spike number per plant, however, was high only when high level of fertilizers were applied to fitilizer responsive group. 13. Slight variations of heritability estimates for heading dates, plant height, spike length, grain number per spike and 1, 000 grain weight were obtained between years. However, the spike number per plant with low heritabilility showed great variation between years. 14. The character that showed high genotypic correlation coefficients with yield in two years was 1, 000 grain weight, and this character was also high in direct effect to yield in terms of path-coefficients. 15. From the above experimental results, it might be concluded that 1, 000 grain weight would be one of the most important characters to increase the effects of selection for yield in wheat breeding in Korea.

• Korean Journal of Occupational Health Nursing
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• v.26 no.1
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• pp.40-46
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• 2017

Purpose: The purpose of this study was to investigate the mediating effect of resilience on the relationship between emotional labor and happiness of clinical nurses. Methods: A descriptive, cross-sectional study was conducted with 224 clinical nurses who had one or more years of clinical experiences from four general hospitals in D city in Korea. Data collected from the survey using self-reported questionnaires were analyzed by t-test, one-way ANOVA, Pearson's correlation coefficients, and multiple regression analysis using IBM SPSS statistics 21.0 program. Results: There were statistically significant correlations among variables; a negative correlation between happiness and emotional labor, a positive correlation between happiness and resilience, and a negative correlation between emotional labor and resilience. Meanwhile, resilience had a partial mediating effect on the relationship between emotional labor and happiness. That is, resilience can play an important role between emotional labor and happiness of clinical nurses as a mediator. Conclusion: Considering the findings of this study, developing programs that can improve resilience of clinical nurses who experience emotional labor are needed to increase their level of happiness.

• The Journal of Internal Korean Medicine
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• v.21 no.3
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• pp.495-504
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• 2000

Objective : To assess the relationship and prevalence rate among hypertension, dyslipidemia and the four commenest anthropometric measurements for obesity(body mass index(BMI), waist-hip ratio(WHR), waist circumference(WC) and body fat) in Korean adults. Methods : We studied the cross-sectional association of the anthropometric indicies and hypertension, dyslipidemia in 70 Korean adults. Hypertension was defined as blood pressure ${\ge}160/95$mmHg and classification of JNC IV, Dyslipidemia were defined as total cholesterol ${\ge}200$ mg/dl, HDL-cholesterol ${le}35$ mg/dl, LDL-cholesterol ${\ge}160$ mg/dl, triglyceride ${\ge}200$ mg/dl. Infromations on life-style factors were obtained from personal interview. Results : BMI and WHR, BMI and WC, BMI and Fat(%), WHR and WC, WC and Fat(%) had high partial correlation coefficients after age adjustment. BMI and Systolic Blood Pressure had r=0.385 coefficients, WHR and HDL-cholesterol had r=-0.360 coefficients. All four anthropomtric indicies and hypertenstion groups by JNC IV classsification had signifiant differences in women, but only fat(%) and hypertension had significant difference in men. In women, in the relationship of four anthropomtric indicies and serum lipids, total cholesterol ${\ge}200$ mg/dl group with fat(%) had a signifiant difference for normal cholesterol group, and also the group of HDL-cholesterol ${\le}$ mg/dl with WC had significance. But in men, there were no significant differences in all anthropomtric indicies and serum lipids groups. Conclusions : Korean women are more significant than Korean men in the relationship between anthropometric indicies and serum lipids, or blood pressure. But this study's samples are small, so the results are some different with results of other studies. We should study more specifically about anthropometric indicies and serum lipids, anthropometric indicies and blood pressure with many samples.

• Composites Research
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• v.19 no.5
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• pp.1-6
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• 2006

In this study, a closed-form analysis has been developed for the transverse shear behavior of thin-walled composite beams with closed cross-sections. The shear flow distributions and cross-section stiffness coefficients are derived analytically by using a mixed beam approach. The theory has been applied to single-celled composite box-beams with elastic couplings. The location of the shear center and the effect of transverse shear deformation on the static behavior of composite beams are investigated in the framework of the analysis. The present results are validated against those of a two-dimensional finite element analysis and a good correlation has been obtained for box-beam cases considered in this study.

• Journal of the Korea Convergence Society
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• v.8 no.11
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• pp.133-139
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• 2017

Objective: The purpose of this study was to examine levels of awareness, attitude and practice of wearing seatbelt of university students using a long distance commute. Methods: A cross-sectional survey design was used to investigate a convenience sample of 118 university students in Chungbuk province. Data was analyzed by descriptive statistics, Pearson correlation coefficients, t-test, ANOVA and Scheffe'test using SPSS version 22. Results: A significant positive correlation was found among awareness, attitude and practice. There were statistically significant differences in awareness, attitude and practice according to some of general characteristics(gender, age, commuting time, the last point of no seatbelt, socioeconomic status). Conclusion: Based on the results of this study, it can be used to develop an accident prevention and health education program.

• Journal of Digital Convergence
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• v.17 no.2
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• pp.255-264
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• 2019

This study was a cross-sectional study done to determine the relevance and impact factors of critical thinking and nursing practice environment on clinical decision making among nurses. A survey was conducted for April 2017 with self-report questionnaire. Participants were 261 registered nurses working in one tertiary hospital. Data were analyzed using descriptive statistics, independent t-test, one-way ANOVA, Pearson's correlation coefficients, and hierarchical regression analysis with SPSS/WIN(21.0). Factors affecting clinical decision making included age, educational background, position, work shift, clinical career. Clinical decision making had a positive correlation with critical thinking and nursing practice environment. And position, critical thinking and nursing practice environment accounted for 35.8% of the variance in clinical decision making. Therefore, quality management for developing nursing professionalism and administrative support for effective staffing and resource adequacy in addition improving critical thinking increase nurses'clinical decision making.

• Journal of Hospice and Palliative Care
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• v.27 no.1
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• pp.11-20
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• 2024

Purpose: Advance directives (ADs) are legal documents that outline a person's preferences or decisions regarding end-of-life care ahead of time. In Korea, there is insufficient awareness and knowledge about ADs among patients undergoing hemodialysis. This study explored the relationship between perceptions of a good death, knowledge about ADs, and attitudes toward ADs in this patient population. Methods: This cross-sectional survey enrolled 119 hemodialysis patients from a secondary hospital in 2021. The participants completed a self-administered questionnaire, and the data were analyzed using the t-test, analysis of variance, Pearson correlation coefficients, Spearman rank correlation coefficients, and multiple regression analysis. Results: The average score for perceptions of a good death among hemodialysis patients was 2.80 out of 4, with clinical symptoms identified as the most critical factor. The average scores for knowledge about ADs and attitudes toward ADs were 5.69 out of 9 and 2.79 out of 4, respectively. There was a positive correlation between perceptions of a good death and attitudes toward ADs (r=0.34, P<0.001), as well as between knowledge about Ads and attitudes toward ADs (r=0.19, P=0.037). Factors influencing attitudes toward Ads included employment status (β=0.22, P=0.011), education level (β=0.22, P=0.013), and perceptions of a good death (β=0.29, P=0.001), which accounted for 24.8% of the variance in attitudes toward ADs. Conclusion: A positive perception of a good death among patients undergoing hemodialysis was associated with a positive attitude toward ADs. Educational programs are needed to improve individuals' understanding of a good death and encourage the development of end-of-life care plans.