• Journal of Korean Society of Disaster and Security
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• v.14 no.1
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• pp.61-72
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• 2021

There is an increasing need for water supply plan using sustainable groundwater to resolve water shortage problem caused by drought due to climate change and artificial aquifer recharge has recently emerged as an alternative. This study deals with recharge potential assessment for artificial recharge system and quantitative assessment for securing stable water and efficient agricultural water supply adapt to drought finding optimal operating condition by numerical modeling to reflect recharge scenarios considering climate condition, target water intake, injection rate, and injection duration. In order to assess recharge potential of injection well, numerical simulation was performed to predict groundwater level changes in injection and observation well respect to injection scenarios (Case 1~4) for a given total injection rate (10,000 m³). The results indicate that groundwater levels for each case are maintained for 25~42 days and optimal injection rate is 50 m³/day for Case 3 resulted in groundwater level rise less than 1 m below surface. The results also show that influential area of groundwater level rise due to injection was estimated at 113.5 m and groundwater storage and elapsed time were respectively increased by 6 times and 4 times after installation of low permeable barrier. The proposed assessment method can be contributed to sustainable agricultural water supply and stable water security for drought adaptation.

• Journal of Periodontal and Implant Science
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• v.51 no.3
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• pp.213-223
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• 2021

Purpose: The atmospheric pressure plasma jet (APPJ) has been introduced as an effective disinfection method for titanium surfaces due to their massive radical generation at low temperatures. Helium (He) has been widely applied as a discharge gas in APPJ due to its bactericidal effects and was proven to be effective in our previous study. This study aimed to evaluate the safety and effects of He-APPJ application at both the cell and tissue levels. Methods: Cellular-level responses were examined using human gingival fibroblasts and osteoblasts (MC3T3-E1 cells). He-APPJ was administered to the cells in the experimental group, while the control group received only He-gas treatment. Immediate cell responses and recovery after He-APPJ treatment were examined in both cell groups. The effect of He-APPJ on osteogenic differentiation was evaluated via an alkaline phosphatase activity assay. In vivo, He-APPJ treatment was administered to rat calvarial bone and the adjacent periosteum, and samples were harvested for histological examination. Results: He-APPJ treatment for 5 minutes induced irreversible effects in both human gingival fibroblasts and osteoblasts in vitro. Immediate cell detachment of human gingival fibroblasts and osteoblasts was shown regardless of treatment time. However, the detached areas in the groups treated for 1 or 3 minutes were completely repopulated within 7 days. Alkaline phosphatase activity was not influenced by 1 or 3 minutes of plasma treatment, but was significantly lower in the 5 minute-treated group (P=0.002). In vivo, He-APPJ treatment was administered to rat calvaria and periosteum for 1 or 3 minutes. No pathogenic changes occurred at 7 days after He-APPJ treatment in the He-APPJ-treated group compared to the control group (He gas only). Conclusions: Direct He-APPJ treatment for up to 3 minutes showed no harmful effects at either the cell or tissue level.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.6
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• pp.573-581
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• 2020

Using CCTV images and weather parameters, a method for estimating PM (Particulate Matter) index was proposed, and an experiment was conducted. For CCTV images, we proposed a method of estimating the PM index by applying a deep learning technique based on a CNN (Convolutional Neural Network) with ROI(Region Of Interest) image including a specific spot and an full area image. In addition, after combining the predicted result values by deep learning with the two weather parameters of humidity and wind speed, a post-processing experiment was also conducted to calculate the modified PM index using the learned regression model. As a result of the experiment, the estimated value of the PM index from the CCTV image was R2(R-Squared) 0.58~0.89, and the result of learning the ROI image and the full area image with the measuring device was the best. The result of post-processing using weather parameters did not always show improvement in accuracy in all cases in the experimental area.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.257-266
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• 2021

Urban areas can often suffer flood damage because of the more frequent catastrophic rainfall events from climate change. Flood mitigation measures consist of (1) structural and (2) non-structural measures. In this study, the proposed method focused on operating an urban drainage system among non-structural measures. The combined inland-river operation technique estimates the inflow of pump stations based on the water level obtained from a preselected monitoring point, and the pump station expels the stored rainwater to the riverside based on those estimates. In this study, the proposed method was applied to the Mokgam drainage watershed, where catastrophic rainfall events occurred (i.e., 2010- and 2011-years), and severe flood damage was recorded in Seoul. Using the proposed method, the efficiency of flood reduction from the two rainfall events was reduced by 34.9 % and 54.4 %, respectively, compared to the current operation method. Thus, the proposed method can minimize the flood damage in the Mokgam drainage watershed by reserving the additional storage space of a reservoir. In addition, flooding from catastrophic rainfall can be prevented, and citizens' lives and property in urban areas can be protected.

• The Journal of the Korea Contents Association
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• v.21 no.3
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• pp.131-142
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• 2021

This research is based on the design of pictures in picture books, and the spatial representation of illustrations in the picture books contains the significantly important objective. Various texts, pictures, spaces, etc. in a picture must have the operator's various editing skills so that spatial arrangement is made smoothly.In this paper, the characteristics of spatial expression of design in picture books are derived by analyzing several examples of paintings and studies on classic picture books. First, the fusion of picture and text, that is, that both picture and text convey spatial information together as elements of the screen. Second, as a characteristic of the coherence of the space design in picture books, the story and content must be smoothly connected when reading the book. Third, when expressing a space, the creator should utilize the strengths and weaknesses of each other between abstract and conceived spatial expressions as needed. Fourth, as a symbolic feature of picture book spatial expression, it can be seen that many symbolic expression techniques are applied to the spatial expression of picture books according to the semiotic principle, which greatly improves the cognitive efficiency of reading picture books. The fifth characteristic is that the spatial expression of an excellent picture book has excellent interesting element, rich design means, and interestingly conveys screen contents and screen format to readers. In this research, it is thought that designers and artists should guide the creation within a spatial framework as designing picture books, thus greatly improving the efficiency of the creation process, while also provide a reader-centered visual Interesting experience.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.115-119
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• 2020

Selective Laser Melting (SLM) technology is state-of-the-art additive manufacturing process technology that produces a three-dimensional structure by irradiating a laser on a fine metal powder to perform the fusion of a specific area and repeat this process. Owing to the characteristics of the additive manufacturing process, the melting phenomenon of the metal material by the laser has directionality depending on the process conditions, such as the irradiation direction of the laser and the build-up direction. For this reason, the composition of the metal material in the structure exhibits non-uniform characteristics. In this study, aluminum (AlSi10Mg) specimens were manufactured by applying SLM technology, and the material composition characteristics of the specimen were analyzed. The specimens were manufactured as cylinders by the build-up orientation of 0°, 45°, and 90°. The surface morphology of the specimen plane was analyzed optically. TEM analysis was performed on the core and the interface of the melting-pool inside the specimen generated by laser irradiation. The analysis results confirmed that there was a difference between the nano cell structure of the core and the interface of the melting-pool, and that the composition ratio of Si appeared higher at the interface than at the core of the cell.

• Journal of the Korea Convergence Society
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• v.12 no.8
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• pp.301-308
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• 2021

In this study, the antioxidant and anti-inflammatory, anti-obesity properties, of Sargassum macrocarpum extracts were identified to assess the availability of Sargassum macrocarpum extracts as cosmetics and foods. To measure antioxidant activity, we conducted TPC, TFC, DPPH, ABTS, NO, FRAP. For polyphenols, 30.81±1.12 mg/g was shown. Flavonoids showed 25.72±0.94 mg/g. The DPPH experiment showed an antioxidant function of 6.746 mg ascorbic acid/g extract, the ABTS experiment showed an antioxidant function of 15.59 mg ascorbic acid/g extract, and the NO experiment showed an antioxidant function of 6.781 mg ascorbic acid/g extract. In FRAP, 1 mg of the Sargassum macrocarpum extract showed a reduction of 4.573±0.097 ㎍ of ascorbic acid. In cytotoxicity experiments, Sargassum macrocarpum extracts showed a cell survival rate of more than 80% at all concentrations, and an inflammatory inhibition of 25.95±0.85%, and an lipid accumulation inhibition of 29.75±2.35%. These results indicate that Sargassum macrocarpum extract is available as an anti-inflammatory cosmetic and anti-obesity inner beauty material. In future studies, it is necessary to study how pure substances containing Sargassum macrocarpum extract affect antioxidants, anti-inflammatory and anti-obesity

• Journal of Korean Home Economics Education Association
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• v.33 no.2
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• pp.81-93
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• 2021

The purpose of this study was to analyze the image, perception, and preference type of high school students of Hanbok and examine the differences according to gender and participation in Hanbok classes. For this purpose, a survey was conducted with 438 high school students in Busan. Frequency analysis, chi-square test, t-test, and F-test were performed using the SPSS and the results were as follows. Firstly, for most high school students, Hanbok has an elegant image, but it was also confirmed that they perceive Hanbok to have a splendid image due to its exposure in mass media and SNS. The image of Hanbok differed by gender and participation in Hanbok classes. A higher percentage of male students than female students perceived Hanbok to have rustic image. Secondly, the type of hanbok that high school students prefer was traditional Hanbok, followed by fusion Hanbok, casual Hanbok, and fashion Hanbok. Hanbok preference type differed by gender and participation in classes. Group participating in hanbok classes showed a higher preference for fashion Hanbok than those who did not. Thirdly, high school students' perception of traditional Hanbok was above average. By subcomponents, it was shown in the order of 'esthetics', 'sustainability', and 'practicality'. It was found that there were statistically significant differences in traditional Hanbok perception according to gender and participation in Hanbok classes. Female students evaluated more positively for traditional Hanbok than male students and students who participate in Hanbok classes evaluated traditional Hanbok more positively than non-participating students.

• The Journal of Korean Society for School & Community Health Education
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• v.22 no.4
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• pp.49-60
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• 2021

Objectives: Laboratories have various latent physical, chemical, biological, and ergonomical factors according to the diversification and fusion of research and development activities. This study aims to investigate the chemical exposure concentrations of college laboratories and evaluate their health risks, and use them as basic data to promote the health of college students. Methods: The sampling and analysis of harmful chemicals in the air in laboratories were performed using Method 1500 of the U.S. National Institute for Occupational Safety and Health (NIOSH)의 Method 1500. The harmful chemicals in the laboratories were divided into carcinogenic and non-carcinogenic chemicals. Risk assessment was performed using the cancer risk (CR) for carcinogenic chemicals and using the hazard index (HI) for non-carcinogenic chemicals. Results: The harmful chemicals in college laboratories consisted of acetone, diethyl ether, methylene chloride, n-hexane, ethyl acetate, chloroform, tetrahydrofuran, toluene, and xylenes. They showed the highest concentrations in laboratories A (acetone 0.001~2.34ppm), B (chloroform 0.95~6.35ppm), C (diethyl ether 0.08~8.68ppm), and D (acetone 0.07~14.96ppm). The risk assessment result for non-carcinogenic chemicals showed that the HI of methylene chloride was 2.052 for men and 2.333 for women, the HI of N-hexane was 4.442 for men and 5.05 for women. Thus, the HI values were higher than 1. The risk of carcinogenic chemicals is determined by an excess cancer risk (ECR) value of 1.0×10^-5, which means that one in 100,000 people has a cancer risk. The ECRs of chloroform exceeded 1.0×10^-5 for both men and women, indicating the possibility of cancer risk. Conclusion: College laboratories showed the possibility of non-carcinogenic health risks for methylene chloride, n-hexane, tetrahydrofuran (THF), toluene, and xylenes, and carcinogenic health risks for chloroform, methylene chloride. However, this study used the maximum values of measurements to determine the worst case, and assumed that the subjects were exposed to the corresponding concentrations continuously for 8 hours per day for 300 days per year. In consideration of the nature of laboratory environment in which people are intermittently exposed, rather than continuously, to the chemicals, the results of this study has an element of overestimation.

• Microbiology and Biotechnology Letters
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• v.49 no.4
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• pp.485-492
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• 2021

In this study, the whitening effect of Abelmoschus esculentus extract was investigated to confirm its applicability in cosmetics. To determine the whitening effect, the tyrosinase-inhibitory activity of Abelmoschus esculentus hot water extract (AEWE) and 70% ethanol extract (AEEE) was measured. At the final concentration of 1000 ㎍/ml, AEWE showed an inhibitory activity of 22.2% and AEEE of 32.8%. To determine the whitening effect at the cellular level, the viability of melanoma cells treated with AEWE and AEEE was evaluated using the MTT assay. At concentrations of 100 ㎍/ml or less, both AEWE- and AEEE-treated groups showed cell survival rates of >95%. Furthermore, in both AEWE- and AEEE-treated melanoma cells, the melanin content decreased in a concentration-dependent manner. The inhibitory effects of AEWE and AEEE used at 5, 10, 50, and 100 ㎍/ml on protein expression were measured by western blot, with β-actin as the positive control. At a concentration of 100 ㎍/ml, AEWE showed an inhibitory effect of 88.1%, 24.8%, 62.2%, and 42.9% on microphthalmia-associated transcription factors (MITF), tyrosinase, tyrosinase-related proteins (TRP)-1, and TRP-2 factors, respectively. At the same concentration, AEEE showed inhibitory effect of 65.3%, 58.3%, 66.2%, and 65.3% against MITF, tyrosinase, TRP-1, and TRP-2 factors, respectively. In conclusion, the whitening effects of AEWE and AEEE were verified, and their applicability as a natural ingredient in cosmetics was confirmed.