• Journal of Digital Convergence
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• v.19 no.3
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• pp.415-423
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• 2021

The purpose of this study was to report the changes in underwater anxiety, physical self-efficacy, and water safety consciousness in elementary school students through participation in survival swimming education, and the relationship between variables. For this purpose, 300 out of 312 elementary school students who participated in survival swimming education in Busan were used as valid samples. The collected data were analyzed through exploratory factor analysis, reliability analysis, correspondence sample t-test, and multiple regression analysis using the SPSS 25.0 statistical program, and the results are as follows. First, the underwater anxiety of elementary school students before and after participating in survival swimming education decreased, and the physical self-efficacy and water safety awareness increased. Second, underwater anxiety of elementary school students who participated in survival swimming education partially negatively affected physical self-efficacy and water safety consciousness, and physical self-efficacy partially positively affected water safety consciousness. Based on these results, the effectiveness of survival swimming education could be confirmed, and the direction of qualitative expansion of the program could be reconsidered.

• Journal of Korea Water Resources Association
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• v.53 no.12
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• pp.1119-1130
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• 2020

Flood disasters have been recently increasing worldwide due to climate change and extreme weather events. Since flood damage recovery has been conducted as a common coping strategy to flood disasters in the Republic of Korea, it is necessary to predict the regional flood damage costs by rainfall characteristics for a preventative measure to flood damage. Therefore, the purpose of this study is to present the regression functions for human and economic flood damage assessments for the 7 metropolises in the Republic of Korea. A comprehensive regression analysis was performed through the total 48 simple regression models on the two types of flood damage records for human and economic costs over the past two decades from 1998 to 2017 using the four kinds of nonlinear equations with each of the six rainfall variables. The damage assessment functions for each metropolis were finally selected by the evaluation of the regression results with the coefficient of determination and the statistical significance test, and then used for the human and economic flood damage assessments for 100-year rainfall in the 7 metropolises. The results of this study are expected to provide the basic information on flood damage cost assessments for flood damage mitigation measures.

• The Journal of the Korea Contents Association
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• v.21 no.5
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• pp.398-408
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• 2021

The purpose of this study is to verify the mediating effects of difficult in emotional regulation and perceived social support on the relationship between adult ADHD tendency and smartphone addiction. For this study, Data were collected from 348 adults in 20s to 30s who live in Seoul, Gyeong-Gi Provinces. The SPSS 21.0 program was used to analyze the statistical data. The data was analyzed by structural equation modeling test mediating effects with AMOS and Mplus.. The results of the analysis were as follows: First adult ADHD tendency was positively correlated with difficulties in emotional regulation and smart phone addiction, while perceived social support was negatively correlated with those variables. Second difficulties in emotional regulation was partially mediated adult ADHD tendency and perceive social support. Third difficulties in emotional regulation and perceived social support had a dual mediating effect on adult ADHD tendency and smartphone addiction. These results reiterate the difficulties in emotional regulation is a determinant for the influence of adult ADHD on smartphone addiction, and suggest that smartphone addiction as an avoidant alternative activity could be reduced by overcoming the difficulties in emotional regulation and promoting the perceived social supports. Finally, some limitations of this study and suggestions for further researches were discussed.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.4
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• pp.199-208
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• 2021

Purpose: The purpose of this study was to compare and evaluate the masking ability of three types of high translucent zirconia according to the various thicknesses and backgrounds. Materials and Methods: Using three types of high-translucency zirconia (Ceramill zolid fx white, Ceramill zolid ht+ white, Ceramill zolid ht+ preshade A2), 10 cylindrical specimens were fabricated in 10mm diameter and each with four thicknesses (0.6 mm, 1.0 mm, 1.5 mm, 2.0 mm), respectively by CAD/CAM method. The background was 10 mm in diameter and 10 mm in thickness. A1, A2, A3 flowable resin backgrounds, blue-colored core resin background, and Ni-Cr alloy background were prepared, and black, white backgrounds provided by the spectrophotometer manufacturer (x-rite, Koblach, Austria) were used. zirconia specimens and the background specimen were stacked to measure L, a^*, b^* with Spectrophotometer (Color i5, x-rite, Koblach, Austria) and the ΔE value with the other background is calculated. The Calculated mean ΔE values were compared based on perceptibility threshold 1.0 and acceptability threshold 3.7. Nonparametric tests such as Kruskal-Wallis test were performed to verify statistical significance (α = 0.05). Results: There was a significant difference in the mean ΔE value according to the zirconia type, background and thickness change (P = 0.000). Conclusion: According to the results of this study, the pre-colored high-translucent zirconia can obtain the desired zirconia shade when it is restored on teeth, composite resins, and abutments except for the blue resin core.

• Journal of dental hygiene science
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• v.21 no.4
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• pp.233-242
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• 2021

Background: The importance of infection with COVID-19 is being emphasized in dentistry with high risks such as aerosols. The purpose of this study is to investigate the knowledge and practice of infection control, stress and coping, and turnover of dental hygienists. Methods: Questionnaire was conducted knowledge and practice of infection control, occupational stress and coping, turnover. Survey data was investigated about 149 dental hygienists from February to March 2021 Data were analyzed t-test, ANOVA, Pearson's correlation using statistical programs of PASW Statistics ver. 21.0. Results: Regarding occupational stress, relationship conflict was higher in the group with less than 2 years of experience (p<0.05). Job anxiety, organizational system, inadequate compensation, and workplace culture were highly surveyed in the 3 to 5 year of experience. The group with more than 6 years of experience had the highest perception of lack of job autonomy (p<0.05). The group with higher knowledge of infection control had lower mean inappropriate rewards and stress (p<0.05). The group with high infection control performance had a lower average in items such as job instability, organizational system, inadequate compensation, workplace culture, and stress. And problem-focused coping ability was found to be high (p<0.05). Infection control knowledge and performance were positively correlated (r=0.251, p<0.01), infection control practice and stress were negatively correlated (r=-0.264, p<0.01), and stress and emotional coping were positively correlated (r=0.367, p<0.01). Stress was positively correlated with turnover rate (r=0.549, p<0.01). Conclusion: Infection control training was required to reduce occupational stress. Occupational stress was highly correlated with turnover, a holistic and systemic organizational operation and improvement of the quality of medical care were required to reduce stress.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.27 no.3
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• pp.129-139
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• 2021

We studied the consumer preference for the packaging of "Samgyetang" retort product in order to improve its function and design. A total of 319 eligible respondents (male 175, female 144) were surveyed with a questionnaire asking on the general characteristics for the preference of the packaging function, type of retort package, packaging design, convenience, cooking method of retort product and characteristics of "Samgyetang" retort product. The collected data was analyzed using a chi-square (X²) statistical test in SPSS program. The results showed that the retort packages with opacity and microwaveable types were preferred. Also, most respondents expressed that it needs to be improved for cooking convenience. Another question results showed that the consumers are considering the taste and cost of a product more important than the brand of its product when purchasing. Based on the results of the questionnaire, the study suggested that many consumers want the convenience of packaging and product protection for high value added product. The results help to provide consumer's demand for packaging development and to provide the greatest advantages in terms of production and marketability of "Samgyetang" retort product.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.4
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• pp.297-304
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• 2021

In this study, we prepared a pigmented skin model, KeraSkin-M^TM for the in vitro evaluation of whitening agents. For the purpose of complementing the existing mono-layer cell culture testing method, KeraSkin-M^TM was produced through the co-culture of human skin-derived keratinocytes and melanocytes. The efficacy of four well-known whitening agents (arbutin, ascorbic acid, kojic acid, niacinamide) was evaluated in KeraSkin-M^TM in order to assess its usefulness in assessing whitening efficacy. As a result, it was possible to observe additional details such as the distribution of melanin granules and melanin capping in each skin layer through KeraSkin-M^TM, which was previously difficult to assess in the traditional 2D cell culture system. In addition, quantification through image analysis of KeraSkin-M^TM allowed for a statistical analysis of the whitening effects. These results suggest that the KeraSkin-M^TM can be used as a new evaluation method of evaluating whitening efficacy, as well as complement the traditional total melanin content and tyrosinase inhibition assays.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.1
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• pp.67-75
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• 2022

Roots play important roles in water and nutrient uptake and in response to various environmental stresses. Investigating diversification of cultivars through root phenotyping is important for crop improvement in adzuki beans. Therefore, we analyzed the morphological and architectural root traits of 22 adzuki bean cultivars using 2-dimensional (2D) root imaging. Plants were grown in plastic tubes [6 cm (diameter) × 40 cm (height)] in a greenhouse from July 25^th to August 28^th. When the plants reached the 2^nd or 3^rd trifoliate leaf stage, the roots were removed and washed with tap water to remove soil particles. Clean root samples were scanned, and the scanned images were analyzed using the WinRHIZO Pro software. The cultivars were analyzed based on six root phenotypes [total root length (TRL), surface area (SA), average diameter (AD), and number of tips (NT) were included as root morphological traits (RMT); and link average length (LAL) and link average diameter (LAD) were included as root architectural traits (RAT)]. According to the analysis of variance (ANOVA), a significant difference was observed between the cultivars for all root morphological traits. Distribution analysis demonstrated that all root traits except LAL followed a normally distributed curve. In the correlation test, the most important morphological trait, TRL, showed a strong positive correlation with SA (r = 0.97^***) and NT (r = 0.94^***). In comparison, between RMT and RAT, TRL showed a significantly negative correlation with LAL (r = -0.50^***); however, TRL did not show a correlation with LAD. Based on RMT and RAT, we identified the cultivars that ranked 5% from the top and bottom. In particular, the cultivar "IT 236657" showed the highest TRL, SA, and NT, while the cultivar "IT 236169" showed the lowest values for TRL, SA, and NT. In addition, the coefficient of variance for the six tested root traits ranged from (14.26-40%) which suggested statistical variability in root phenotypes among the 22 adzuki bean varieties. Thus, this study will help to select target root traits for the adzuki bean breeding program in the future, generating climate-resilient adzuki beans, especially for drought stress, and may be useful for developing biotic and abiotic stress-tolerant cultivars based on better root trait attributes.

• Journal of Korea Entertainment Industry Association
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• v.14 no.1
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• pp.159-166
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• 2020

This study was conducted on 20 healthy adults in their 20s to identity the immediate effects of balance, proprioception and flexibility after conducting the PNF combined patterns using 3D Newton box. The data collected in this study were analyzed using the SPSS Window 19.0 statistical program, and the general characteristics of the subjects were calculated by calculating the mean and standard deviation using the technical statistics, and the differences before and after in-group balance, proprioception and flexibility were analyzed by the paired t-test. The balance, proprioception and flexibility of the subjects were measured using Y-balance, one-leg standing, and finger bottom contact. The exercise was applied with an combined pattern of PNF in the 3D Newton box. After exercise, balance, proprioception and flexibility all increased significantly. The results show that combined pattern of PNF using the 3D Newton box immediately works for the balance, proprioception and flexibility of adults in their 20s. Therefore, it is considered to be an exercise that can be actively utilized for adults or patients at high risk of damage due to reduced balance, proprioception and flexibility.

• The Korean Journal of Applied Statistics
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• v.35 no.4
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• pp.543-552
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• 2022

When frost occurs, crops are directly damaged. When crops come into contact with low temperatures, tissues freeze, which hardens and destroys the cell membranes or chloroplasts, or dry cells to death. In July 2020, a sudden sub-zero weather and frost hit the Minas Gerais state of Brazil, the world's largest coffee producer, damaging about 30% of local coffee trees. As a result, coffee prices have risen significantly due to the damage, and farmers with severe damage can produce coffee only after three years for crops to recover, which is expected to cause long-term damage. In this paper, we tried to predict frost using frost generation data and weather observation data provided by the Korea Meteorological Administration to prevent severe frost. A model was constructed by reflecting weather factors such as wind speed, temperature, humidity, precipitation, and cloudiness. Using XGB(eXtreme Gradient Boosting), SVM(Support Vector Machine), Random Forest, and MLP(Multi Layer perceptron) models, various hyper parameters were applied as training data to select the best model for each model. Finally, the results were evaluated as accuracy(acc) and CSI(Critical Success Index) in test data. XGB was the best model compared to other models with 90.4% ac and 64.4% CSI, followed by SVM with 89.7% ac and 61.2% CSI. Random Forest and MLP showed similar performance with about 89% ac and about 60% CSI.