• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.4
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• pp.445-454
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• 2018

The aim of this study was to measure the shear bond strength (SBS) of different adhesive systems to calcium silicate-based materials (Biodentine and RetroMTA). Eighty cylindrical acrylic blocks, with a hole (5.0 mm diameter, 2.0 mm height) in each, were prepared. The holes were filled with Biodentine (BD) and RetroMTA (RMTA), and the specimens were divided into 2 groups. Each group was classified into 4 subgroups: Clearfil$^{TM}$ SE (CSE) ; AQ bond (AQ) ; All bond universal Self-etch (ABU-SE) ; and All bond universal Total-etch (ABU-TE). After the application of different adhesive systems, composite resin (Z350) was applied over BD and RMTA. The SBS was measured using a universal testing machine, and the data were compared using the Kruskal-Wallis test and the Mann-Whitney test. The highest and lowest values of SBS were observed for BD-ABU-SE and RMTA-AQ, respectively. No significant differences were found in the SBS between ABU-TE and ABU-SE and between ABU-TE and CSE to BD and RMTA. According to the data, BD showed a higher SBS than did RMTA when BD and RMTA are compared in the same adhesive agents. Further, among all groups, composite resin with ABU-SE showed better bond strength to BD and RMTA.

• Journal of Korea Water Resources Association
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• v.32 no.4
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• pp.403-415
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• 1999

This study is to derive the rainfall intensity formula based on the representative probability distribution in Korea. The 11 probability distributions which has been widely used in hydrologic frequency analysis are applied to the annual maximum rainfall. The parameters of each probability distribution are estimated by method of moments, maximum likelihood method and method of probability weighted moments. Four tests such as $x^2$-test, Kolmogorv-Smirnov test, difference test and modified difference test are used to determine the goodness of fit of the distributions. The homogeneous tests (Mann-Whitney U test, Kruskal-Wallis one-way analysis of variance of nonparametric test) are applied to find the stations with rainfall homogeneity. The results of homogeneous tests show that there is no representative appropriate distribution for the whole duration in Korea. The whole region could be divided into five zones for 12-durations. The representative probability distribution of each divided zone for 12-durations was determined. The GEV distribution for I,II,V zones and the 3-parameter Weibull distribution for III,IV zones were determined as the representative probability distribution. The rainfall were obtained from representative probability distribution for the selected return periods. Rainfall intensity formula was determined by linearization technique for the rainfall.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.3
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• pp.181-187
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• 2014

Forest floor is one of most distinctive features of forest ecosystem, which provides plants and soil microbes with nutrients, and controls hydrologic condition within the floor by intercepting water during a rainfall event and evaporates back into the atmosphere. In this study rainfall interception loss by decomposed forest floor of a deciduous forest has been experimentally estimated using rainfall simulation experiments. Litter-decomposing fungi were incubated on deciduous forest floor samples for the experiment purposes. On a deciduous floor, a $4.22mm{\cdot}kg^{-1}{\cdot}m^2$ of rain was intercepted immediately before rain ceased. Minimum values of interception loss ranged from 1.62 to $2.41mm{\cdot}kg^{-1}{\cdot}m^2$, with an average of $1.87mm{\cdot}kg^{-1}{\cdot}m^2$. Mann-Whitney test showed that decomposing fungi on the forest floor influenced on rainfall interception capacity.

• Journal of the Korea Convergence Society
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• v.8 no.9
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• pp.135-142
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• 2017

The purpose of this study was to investigate the effect of smoking, drinking and stress on premenstrual syndrome in female college students. From January 19 to March 1, 2017, the 218 data were collected from university students in Jeonnam, who don't have any parity and uterus disease. Analyzed using Mann-Whitney U test, simple regression analysis with SPSS23. As a result, there was a statistically significant positive correlation between stress and premenstrual syndrome($R^2=.155$, ${\beta}=.393$, p<.001). But, there was no difference in PMS level according to existence of drinking(or smoking) experience. This study had a meaningful result to figure out factors influencing on female college student PMS and offered basic data for developing premenstrual syndrome care programs and nursing intervention. To manage PMS effectively, it is nessasary to develop Convergence Nursing intervention to reduce stress.

• Journal of Korean Society of Forest Science
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• v.103 no.1
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• pp.43-50
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• 2014

The purpose of study was to analyze secreted nectar volume, nectar sugar content and amino acid in addition to estimating honey quantities that can ultimately reap in male and female flowers of Evodia daniellii Hemsl.. The maximum blooming period of male flowers was on 24 to 26 July in 2012. On average, nectar volume secreted by nectary was $2.73{\pm}0.73{\mu}L$ from one male flower and nectar concentration showed 17.4%. The maximum blooming period of female flowers was on 7 to 9 August in 2012. Nectar volume secreted by nectary was $0.63{\pm}0.49{\mu}L$ from one female flower and nectar concentration showed 25.7%, averagely. As results of correlation analysis between the meteorological factors and nectar characteristics, we found that nectar quantities and concentration were influenced by temperature and relative humidity. Sugar content was calculated at $48.0{\pm}5.2{\mu}g$ per a male flower and $37.8{\pm}8.7{\mu}g$ per a female flower, which meant that both values were not significantly different (Mann-Whitney's U-test, p=0.400). The minimum estimates of honey harvest for a male and female inflorescence were 67.8 g and 53.5 g, respectively. Analysis of amino acid showed that Serine, Glycine and Alanine were more abundant in male flowers, however Asparatate, Glutamate, Asparagine and Glutamine were more abundant in female flowers.

• Restorative Dentistry and Endodontics
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• v.34 no.3
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• pp.215-222
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• 2009

The aim of this in vitro study was to evaluate the cleaning efficacy of various irrigation methods in the mandibular mesial roots. The forty five mesial root canals were shaped by Profile .06 instruments to apical size #30 and irrigated with 5ml of 3.5% NaOCl. The teeth were divided into 3 groups and irrigated finally for 1 minute; Group 1: syringe irrigation. Group 2: ultrasonic irrigation. Group 3: RinsEndo irrigation. After histological processing, the cross sections of apical 1, 3, and 5 mm level were examined with an optical microscope. The cleanliness values of canals and isthmuses were calculated and analyzed by Mann-Whitney U test. 1. There were no significant differences in both canal and isthmus cleanliness between syringe irrigation and ultrasonic irrigation except 5 mm level of isthmus. 2. RinsEndo irrigation had significantly higher canal cleanliness values than syringe irrigation at 1 mm and 3 mm levels (p<0.05). Also, RinsEndo irrigation had significantly higher isthmus cleanliness values than syringe irrigation at all levels evaluated (p<0.05). 3. There were no statistical differences in both canal and isthmus cleanliness between ultrasonic irrigation and RinsEndo irrigation except 3 mm level of canal. From this study, RinsEndo irrigation can be useful as an additional irrigation procedure.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.519-532
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• 2016

Purpose: This study aimed to evaluate the effect of an HIV/AIDS education program for professional graduate medical school students using a teaching-learning methods. Methods: The design of this study was a nonequivalent control group pretest-posttest experiment. A total of 116 professional graduate medical school students in South Korea were included. They were randomly assigned to either a discussion-centered teaching-learning method group (n=60) or a lecture-centered teaching-learning method group (n=56). Data were collected between August and December 2015 and were analyzed using descriptive statistics, ${\chi}^2$-test, one-tailed independent t-test, one-tailed Mann-Whitney U-test, one-tailed Wilcoxon signed-rank test, and one-tailed paired t-test using SPSS WIN 19.0 program. Results: There was no statistically significant difference between the two groups with respect to HIV/AIDS knowledge, attitudes, and education satisfaction. However, the scores of knowledge and attitudes were statistically significantly increased after the education than before the education in both groups. Conclusion: To effectively improve the knowledge and attitude of HIV/AIDS, it is necessary to select an appropriate teaching-learning method for the target subjects and objectives of HIV/AIDS education.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.261-270
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• 2016

This study attempted to survey nursing students' motives for choosing nursing as their major, and to examine how such motives affect their satisfaction with their major, campus-life satisfaction, and self-directed learning ability. This study was conducted as a descriptive survey. Data were collected using a self-report questionnaire during the period from the 1st to 15th of April, 2015, and the questionnaires from 195 nursing students were used in the analysis using Fisher's exact test, t-test, one way ANOVA, Mann Whitney test, and ANCOVA. Only 41.5% of the nursing students chose nursing as their major because of their aptitude and interest. The motive for the selection of the major was found to have a significant effect on their satisfaction with the major (p<.001), campus-life satisfaction (p=.008), and self-directed learning ability (p=.001). Middle and high school students should be provided with various types of information on nursing, so that they can have the opportunity to choose nursing based on their aptitude and interest before entering university. Once they start university, nursing students' adjustment to campus-life and learning ability should be enhanced through various extracurricular activity programs in order to stimulate their interest in the major.

• Restorative Dentistry and Endodontics
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• v.30 no.1
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• pp.22-30
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• 2005

The purpose of this study was to compare the effect of surface sealing materials on microleakage and surface roughness in Class V composite restorations. Twenty five standardized Class V cavity preparations were made on the facial surface of human premolars and were randomly assigned to 5 groups. The teeth were restored with Z-250 after applying Single Bond. Following 7 days storage in distilled water at $37^{\circ}C$, the restorations were sealed as following systems : No sealing ; Single Bond Adhesive ; Biscover ; Fortify ; Optiguard. Then, toothbrush abrasion test was conducted using a wear testing machine. Surface roughness was measured by means of profilometer before and after toothbrushing and the results were statistically analysed by using a paired t-test and ANOVA. The bonded interfaces and the changes of surface roughness were examined by SEM. For microleakage test, specimens were stained in a $2\%$ methylene blue solution, then longitudinally sectioned and analyzed for leakage at occlusal and cervical interfaces using stereomicroscope. The results were statistically analysed by using a Kruskal-Wallis and Mann-Whitney U test. Surface roughness was increasing in all groups after toothbrushing, but no statistically significant differences. In SEM observation, surface sealant was partially retained and partially detached in bonded interfaces. Especially, microgap was identified in cervical margins. In microleakage test, there was better seal in the enamel region and a significant difference between groups at occlusal margin. Control group and Single Bond group had significantly better marginal seal at enamel margin than cervical margin.

• Journal of the Korean Society of Radiology
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• v.15 no.5
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• pp.603-612
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• 2021

The effect of Advanced Modeled Iterative Reconstruction (ADMIRE) on the coronary artery calcium (CAC) score of computed tomography was evaluated. Coronary artery calcium images (348 calcium, 6 groups, total of 2088 calcium) were acquired by 128-slice dual-source CT of 89 patients.Volume score and Agatston score were measured from images reconstructed with filtered back projection (FBP) and ADMIRE (1-5). The difference between FBP and ADMIRE Strength (1-5) was confirmed through the Kruskal-Wallis test, and the post-hoc analysis was performed using the Mann-Whitney U test based on FBP. Both volume score and Agatston score showed statistically significant differences between FBP and ADMIRE (1-5) (P=0.015, P=0.0.38). As a result of post hoc analysis, the volume score decreased to 9.5% in ADMIRE 4 (Z=-2.359, P=0.018) and 13.2% in ADMIRE 5 (Z=-3.113, P=0.002) based on FBP. Agatston score decreased to 10.4% in ADMIRE 4 (Z=-2.051, P=0.040) and 14.0% in ADMIRE 5 (Z=-2.718, P=0.007) based on FBP. High ADMIRE strength affected the volume score and Agatston score due to the decrease in calcium area. In addition, the change in the Density factor due to the decrease in Maximum HU may affect the calculation of the Agatston score.