• Journal of the Korean Society for Aviation and Aeronautics
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• v.28 no.2
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• pp.53-62
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• 2020

This study is to evaluate the accuracy of the meteorological information provided for the aircraft operating at low altitude. At first, it is necessary to identify crucial elements of weather information closely related to flight safety during low altitude flights. The study conducted a survey of pilots of low altitude aircraft, divided into pre-flight and in-flight phases, and reached an opinion that wind direction, wind speed, cloud coverage and ceiling and visibility are important items. Related to these items, we compared and calculated the accuracy of TAFs and METARs from Taean Airfield, Seosan Airport and Gunsan Airport because of their high number of domestic low-altitude flights. Accuracy analysis evaluated the accuracy of two numerical variables, Mean Absolute Error(MAE) and Root Mean Square Error(RMSE), and the cloud coverage which is categorical variable was calculated and compared by accuracy. For numeric variables, one-way ANOVA, which is a parameter-test, was approached to identify differences between actual forecast values and observations based on absolute errors for each item derived from the results of MAE and RMSE accuracy analyses. To determine the satisfaction of both normality assumptions and equivalence variability assumptions, the Shapiro-Wilk test was performed to verify that they do not have a normality distribution for numerical variables, and for the non-parametric test, Kruscal-Wallis test was conducted to determine whether or not they are satisfied.

• The Korean Journal of Applied Statistics
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• v.17 no.3
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• pp.459-473
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• 2004

It has well known that an exhaustive search algorithm suggested by Breiman et. a1.(1984) has a trend to select the variable having relatively many possible splits as an splitting rule. We propose an algorithm to overcome this variable selection bias problem and then construct unbiased regression trees based on the algorithm. The proposed algorithm runs two steps of selecting a split variable and determining a split rule for binary split based on the split variable. Simulation studies were performed to compare the proposed algorithm with Breiman et a1.(1984)'s CART(Classification and Regression Tree) in terms of degree of variable selection bias, variable selection power, and MSE(Mean Squared Error). Also, we illustrate the proposed algorithm with real data sets.

• The Korean Journal of Rehabilitation Nursing
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• v.3 no.2
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• pp.169-181
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• 2000

The purpose of this study was to identify the effect of follow-up care for stroke survivors on primary caregivers' quality of life. Quasi-experimental research was conducted in which an experimental group and a control group-each of 15 stroke survivors and their primary caregivers-were consecutively sampled. Data collected from July to September, 1999 by interview using a structured questionnaire with both the experimental and the control groups. After a month, the two groups were given the same questionnaire. The experimental group was also given a telephone follow-up every week for a month, as well as a home visit. The survey instruments used in this study were Saha and Cooper's "Modified Barthel Index" (11 items) for checking the stroke survivors' level of activities of daily living, and a modified form of Jeong's "Quality of life" (18 items) for primary caregivers' QOL level. The obtained data were analyzed by percentage, t-test, $X^2$-test, Kruscal-Wallis test, Spearman correlation coefficient by SAS/PC program. The results were as follows: 1. There was no significant difference in the stroke survivors' ADL level, though the level of the experimental group was higher than that of the control group. 2. There was a statistical difference in the before and after treatment of the primary caregivers' QOL level. In conclusion, the follow-up care program had a useful effect on the quality of life of primary caregivers.

• Korean Business Review
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• v.6
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• pp.201-228
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• 1993

The objective of this research is to investigate the attetudes of religious groups(christian, buddhist, atheist) towards corporate social expenditures. Methodology was a questionnair survey. The data analysis was done by the Kruscal Wallis test and Wilcoxon signed ranks test. The results of this rssearch is that the difference of attitudes between christian group and other groups and between religious groups and atheist group on the social expenditures did not turn out to be statistically significant. The implication of this results is that the variables of religious groups can be ignored when we are going to study on the attitudes of values for the Korean people.

• Journal of Korean Home Economics Education Association
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• v.25 no.1
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• pp.79-94
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• 2013

In this study, the teaching-learning materials and the plan using persimmon juice dyeing, which is one of the traditional natural dyeing methods of Korea, were developed for the purpose of inspiring further awareness of our traditional clothing life-culture. A questionnaire was designed to make a survey on the educational effect, and t-test and Kruscal-Wallis test were conducted to test the significant differences between pre- and post-lessons. A correlation analysis between culture awareness and its education awareness was also done. These prototypes were applied to high school Technology Home Economics classes under the theme, 'Making living goods with persimmon juice dyed fabrics'. Examining the changes in students' awareness of traditional images, and changes in their interest and attitude towards learning in those classes led to the following results. First, as a result of applying LT cooperative learning in order for an understanding of the formation of clothing life-culture and the process of persimmon juice dyeing, many original handicrafts with modern sense were created. Second, a comparative analysis between pre- and post-lessons on the change in students' degree of awareness of traditional clothing life-culture and its education showed that students' awareness had risen after the class; the data was collected from three separate sample groups which had been clustered according to their initial degree of awareness, i.e. high, middle, and low, and the group that scored the lowest before the class showed the greatest improvement. Third, feedback surveys on 'Making living goods with persimmon juice dyed fabrics' classes returned with scores greater than 'moderate', thus revealing that the students' concern and interest towards traditional clothing life-culture hae been enhanced through the class experience. Their attitude had also become more positive. Fourth, since learners with more awareness of the traditional clothing life-culture also showed more awareness of the need for an education designed to promote the culture, a positive correlation between the two had been found. As explained above, the teaching-learning materials and the plan that had been developed for this study has caused a deeper understanding of the value and significance of the traditional natural dyeing and clothing life-culture, and has therefore brought about an educational effect that powers idea creation.

• Korean Journal of Human Ecology
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• v.22 no.2
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• pp.365-374
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• 2013

The purposes of this study were to evaluate the color characteristics and color sensibility of mulberry/cotton blended fabrics dyed with indigo, the natural dye, and analyze effects of them on color preferences. The values of CIE $L^*$, $a^*$, $b^*$ $C^*$, h were calculated for the color characteristics of indigo-dyed fabrics, and their hue, value, and chroma were calculated according to the Munsell color system. Fifty male and female college students evaluated the color sensibility of nine types fabrics dyed with indigo on a seven-point scale. The data were analyzed by descriptive statistics, factor analysis, Kruscal-Wallis test, correlation analysis, and regression analysis. The mulberry/cotton blended fabrics naturally dyed with indigo showed the characteristics of PB color tones, low value, and low chroma. The color sensibilities of fabrics dyed with indigo were classified into four factors: 'classic', 'sporty', 'elegant' and 'natural'. There were significant differences according to the fibers and the repeating times of dyeing in the color sensibility for the fabrics. Cotton fabrics were evaluated to be more classic, sporty, elegant, and natural than the mulberry/cotton blended fabrics, and the deeper the color, the more classic, sporty, and elegant the fabric was evaluated. The students preferred the indigo dyed fabrics which have more classic, sporty, and natural sensibility. There were significant relationships between the color sensibilities and colorimetric properties of the fabrics dyed with indigo. The color preferences of the dyed fabrics with indigo were found to be influenced by the 'classic', 'sporty', 'natural' of color sensibility.

• IMMUNE NETWORK
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• v.6 no.1
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• pp.43-51
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• 2006

Background: The DR-$70^{TM}$ immunoassay is a newly developed cancer diagnostic test which quantifies the serum fibrin degradation products (FDP), produced during fibrinolysis, by antibody reaction. The purpose of this study was to evaluate the potential of DR-$70^{TM}$ Immunoassay in screening malignant tumor. Methods: Sample subjects were 4,169 adults, both male and female, who visited the health promotion center of a general hospital from March 2004 to April 2005 and underwent the DR-$70^{TM}$ immunoassay test and other tests for cancer diagnosis. The patient group was defined as 42 adults out of the sample subjects who were newly diagnosed with cancer during the same time period when the DR-$70^{TM}$ immunoassay test was performed. Final confirmation of a malignant tumor was made by pathological analysis. Results: The mean DR-$70^{TM}$ level was $0.83{\pm}0.65{\mu}g/ml$ (range: 0.00 (0.0001)${\sim}7.42{\mu}g/ml)$ in the control group (n=4,127) as opposed to $2.70{\pm}2.33{\mu}g/ml$ (range: $0.12{\sim}9.30{\mu}g/ml)$ in the cancer group (n=42), and statistical significance was established (p<0.0001, Student t-test). When categorized by the type of malignant tumor, all cancer patients with the exception of the subgroups of colon and rectal cancer showed significantly higher mean DR-$70^{TM}$ levels compared with the control group (p<0.0001, Kruscal-Wallis test). The receiver operating characteristic (ROC) curve analysis revealed ${\geq}1.091{\mu}g/ml$ as the best cut-off value. Using this cut-off value, the DR-$70^{TM}$ immunoassay produced a sensitivity of 71.4%, a specificity of 70.1%, a positive predictability of 69.4%, and a negative predictability of 69.2% (1). Conclusion: A significant increase in the mean DR-$70^{TM}$ value was observed in the cancer group (thyroidal, gastric, breast, hepatic and ovarian) com pared with the control group. In particular, the specificity and sensitivity of the DR-$70^{TM}$ immunoassay was relatively high in the subgroups of breast, gastric, and thyroidal cancer patients. There is need for further studies on a large number of malignant tumor patients to see how the DR-$70^{TM}$ level might be changed according to the differentiation grade and postoperative prognosis of the malignant tumor.

• Journal of Korean society of Dental Hygiene
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• v.10 no.5
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• pp.831-839
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• 2010

Objectives : The purpose of this study was to examine dental hygiene students' image of dental hygienist and factors affecting the image of dental hygienist in an effort to provide some information useful for dental hygiene education. It's basically meant to recreate the image of dental hygienist as a professional. Methods : The subjects in this study were 310 sophomores and seniors who ere selected by convenience sampling from three different three-year-course colleges located in Gyeonggi Province, Chungcheong Province and Gwangju. After a survey was conducted, the answer sheets from 277 respondents were analyzed except for 33 incomplete ones. The collected data were analyzed with a SPSSWIN 17.0 program, and statistical data on frequency and percentage were obtained to find out the general characteristics of the subjects, and another statistical data on mean and standard deviation for each item were acquired to check their image of dental hygienist. Besides, t-test, ANOVA and Kruscal-Wallis test, one of nonparametric test, were utilized to look for connections between their general characteristics and image of dental hygienist. Results : 1. They gave a mean of 3.53 to the image of dental hygienist, which showed that the dental hygiene students took a favorable view of dental hygienists in general. 2. Their response to four items showed that they looked at the image of dental hygienist in a positive manner. The four items respectively described dental hygienists as professionals, as ones who played a crucial role in the improvement of national oral health, as ones with professional knowledge and sophisticated knowhow, and as neat and decent people. And their response to the following five items indicated that they looked at the image of dental hygienists in a negative way. One was that dental hygienists were considered to be dental nurses, and another was that the occupation of dental hygienist was a demanding and stressful job. The third was that there was no single, fixed title to call dental hygienists, and the fourth was that dental hygiene wasn't recognized as an independent area. The fifth was that the social standing of dental hygienists was sort of high. 3. In regard to the impact of the general characteristics of the dental hygiene students on their image of dental hygienist, they had a more favorable image of dental hygienist when they perceived dental hygiene in a more positive manner(p<0.001). Conclusions : In order to boost the image of dental hygienist, the working conditions of dental hygienists should be improved, and educational programs should be prepared to provided them extended continuing educational opportunities. And the kind of educational environments that could nurture dental hygienists who are convinced and have a vision should be created.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.216-224
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• 2008

The purpose of this study was to evaluate the effectiveness of fissurotomy and double application time of acidic primer of self-etching adhesive system of acid treatment on enamel surfaces for prevention of microleakage of pit and fissure sealants. The microleakage of pit and fissure sealants was evaluated by measuring the penetration depth of methylene blue solution. Specimens were divided by 4 groups according to the method of treatment. Group I: 35% phosphoric acid etching, 20 seconds. Group II: Priming with self-etching primer, 20 seconds. Group III: Priming with self-etching primer, 40 seconds. Group IV: Priming with self-etching primer, 20 seconds, after fissurotomy. The etched pattern produced on enamel was observed using a scanning electron microscope. Obtained data were analysed statistically using Kruscal-Wallis test followed by Mann-Whitney test for comparison of groups. The results are as follows: 1. Microleakage scores of group IV priming with self-etching primer 20 seconds after fissurotomy was the lowest. 2. Microleakage scores between group II and group III were not shown significant difference. 3. Enamel for 20 seconds etching with 35% phosphoric acid was observed the most effective etching pattern. And the etching pattern on the fissure enamel with self-etching adhesive 20 seconds after fissurotomy was more prominent than group II, III only using self-etching primer.

• Korean Journal of Health Education and Promotion
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• v.14 no.2
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• pp.171-184
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• 1997

The purpose of this study was to identify the adolescent girl's weight control practices, degree of obesity and body image. The data were collected from July 1st to 15th, 1996 using the questionnaire and the physical examination record. The subjects of this study were 295 junior high school girls. Darta were analyzed with percentages, means, t-test, ANOVA, Kruscal-Wallis one way ANOVA, Scheffe test and pearson correlation coefficients using the SPSS program. The results were as follows: 1. The mean for the degree of obesity in subjects was -1.26%. The 34.2% of the subjects were underweight, the 46.8% were normal, the 9.2% were overweight and the 9.8% were obese. The girls who perceived themselves obese were 39% and only the 47% of them were really over-weight and obese. 2. The mean score of body image was 139.30. It was 145.51 for underweight girls, 128.07 for normal weight girls and 125.17 for obese girls. The higher the degree of obesity was, the lower body image score was. The body image score of the girls who perceived themselves obese was significantly lower than that of the girls who perceived themselves normal or underweight. 3. The 65.1% of subjects experienced weight control practices. They reported that they had used the following weight control methods such as diet(42.2%), exercise(35.9%), diet and exercise(15.1%) and others including drug(6.8%). The degree of obesity was significantly higher and the body image score was significantly lower in the case of the girls who had weight control experiences than in the case of those who had no weight control experiences. 4. The 60% Of the subjects often had 2 meals per day. The 48.8% of the subjects tended to skip breakfast, the 7.8% would skip lunch and the 20% did not have dinner. The higher the degree of obesity was and the lower body image score was, the more the girls would skip their meals. In conclusion, many adolescent girls tended to believe their body weight heavier than their real body weight. Many girls who were not overweight and obese tried to lose weight. In the case of the girls whose degree of obesity was high or who perceived themselves obese, the body image score tended to get lower and the weight control practices tended to be increased.