• Korean Journal of Clinical Laboratory Science
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• v.52 no.4
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• pp.372-380
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• 2020

In this study, the sterilization ability of S. aureus and P. aeruginosa was evaluated using a plasma generator with a flexible electrode structure. Both strains were prepared at a concentration of 1.5×106 CFU/mL and inoculated and spread evenly on two medium plates. The medium were kept at a distance of 3 cm and 9 cm from the plasma generator and were plasma discharged from 30 sec to 10 minutes. The growth of colonies on the media, were subsequently compared with the control group. The mean colonies of S. aureus formed at a 3 cm distance were 9.2×102 (log value 2.96) CFU/mL for the 5 min discharge period and 8.0×10 (1.90) CFU/mL for the 10 min discharge period. When the medium was exposed for 5 min and 10 min at a 9 cm distance, the mean colonies of S. aureus formed were 2.16×103 (3.33) and 2.4×102 (2.38) CFU/mL, respectively. The medium containing P. aeruginosa kept at a 3 cm distance and exposed to 3, 5, 10-minute discharge, did not form any colonies. When kept at a 9 cm distance for 3 minutes, 6.0×102 (2.78) CFU/mL mean colonies were formed but no colonies were formed at exposure periods of 5 and 10 minutes. This enhanced sterilization effect was confirmed in experiments of S. aureus and P. aeruginosa using TiO2.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.4
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• pp.571-580
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• 2020

In this study, an experimental study on storage media for thermal energy storage system was conducted. For thermal energy storage medium, concrete has excellent thermal and mechanical properties and also has various advantages due to its low cost. In addition, the ultra-high strength concrete reinforced by steel fibers exhibits excellent durability against exposure to high temperatures due to its high toughness and high strength characteristics. Moreover, the high thermal conductivity of steel fibers has an advantageous effect on heat storage and heat dissipation. Therefore, to investigate the temperature distribution characteristics of ultra-high-strength concrete, concrete blocks were fabricated and a heating test was performed by applying high-temperature thermal cycles. The heat transfer pipe was buried in the center of the concrete block for heat transfer by heat fluid flow. In order to explore the temperature distribution characteristics according to different shapes of the heat transfer pipe, a round pipe and a longitudinal fin pipe were used. The temperature distribution at the differnent thermal cycles were analyzed, and the thermal energy and the cumulated thermal energy over time were calculated and analyzed for comparison based on test results.

• 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.

• Journal of the Korea Society of Computer and Information
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• v.27 no.3
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• pp.53-61
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• 2022

Recent years have drawn a great attention to generation MZ and Metaverse, due to 4th industrial revolution and the development of digital environment that blurs the boundary between reality and virtual reality. Generation MZ approaches the information very differently from the existing generations and uses distinguished communication methods. In terms of learning, they have different motivations, types, skills and build relationships differently. Meanwhile, Metaverse is drawing a great attention as a teaching method that fits traits of gen MZ. Thus, the current research aimed to investigate how to increase the use of Metaverse in Educational Technology. Specifically, this research examined the antecedents of popularity of Gather Town, a platform of Metaverse. Big data of news articles have been collected and analyzed using the Bigkinds system provided by Korea Press Foundation. The analysis revealed, first, a rapid increasing trend of media exposure of Gather Town since July 2021. This suggests a greater utilization of Gather Town in the field of education after the COVID-19 pandemic. Second, Word Association Analysis and Word Cloud Analysis showed high weights on education related words such as 'remote', 'university', and 'freshman', while words like 'Metaverse', 'Metaverse platform', 'Covid19', and 'Avatar' were also emphasized. Third, Network Analysis extracted 'COVID19', 'Avatar', 'University student', 'career', 'YouTube' as keywords. The findings also suggest potential value of Gather Town as an educational tool under COVID19 pandemic. Therefore, this research will contribute to the application and utilization of Gather Town in the field of education.

• The Journal of the Korea Contents Association
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• v.21 no.12
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• pp.400-407
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• 2021

Recently, mukbang and cookbang or cooking shows on TV and YouTube channels have increased, and the influences of these broadcasts on food consumption have been gradually increasing. There were several news articles on 'Baek Jong-won effect', in which the consumption of the agri-food Mr. Jong-won Baek mentioned on his broadcast soared, and even foods named after him are on the market. In this study, Mr. Jong-won Baek, who produces influential cooking contents through various media, was taken as a representative example. We evaluated if 'Baek Jong-won effect' exists on potato consumption, which Mr. Jong-won Baek broadcasted potato cooking recipes on TV and YouTube. After the potato recipe was broadcasted for the first time on the TV show called HomeFoodRescue, the differences in the amount of money to purchase potatoes before and after the broadcast were estimated by using the money amount to purchase data of Agri-food consumers panel and the difference-in-differences method at 6 time points (3, 6, 9, 12, 24, and 36 months). Among the time points analyzed, the potato purchases at post-broadcast were less than those at pre-broadcast. No results were observed suggesting the existence of 'Baek Jong-won effect' on potato consumption through HomeFoodRescue show in the study.

• The Journal of the Korea Contents Association
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• v.21 no.11
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• pp.490-502
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• 2021

Horticultural facility farmers subscribe to crop accident insurance and insurance products secured by horticultural facilities in preparation for possible risks in the facility. Insurance is purchased to prepare for natural disasters such as typhoons, hail, frostbite, heavy rain, and strong wind damage covered by the product. In order to find out the effect of risk perception, which is a subjective perception of the risks of a given situation, on horticultural facility farmers' intention to purchase horticultural facility insurance products, the risk perception and insurance purchase intention were analyzed. A t-test was conducted to determine the impact relationship between farm size, insurance coverage, and risk perception, and multiple regression analysis was conducted to verify the effect of personal characteristics and behavioral factors such as subjective perception, reference group, media exposure, and compensation understanding. In addition, a three-step regression analysis by Baron & Kenny was conducted to confirm the mediating role of personal characteristics and behavioral factors in the relationship between risk perception and insurance purchase intention. As a result of the study, although there was no difference in farm size, it was analyzed that policy holders had a higher degree of risk perception than non-subscribers, and that compensation understanding had the greatest influence and subjective knowledge had the smallest influence. In addition, these four factors were verified to have a mediating effect on the relationship between risk perception and insurance purchase intention. These results are expected to provide practical help to the development and marketing activities of horticultural facility insurance products.

• Journal of fish pathology
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• v.35 no.1
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• pp.57-63
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• 2022

Vibrio parahaemolyticus and V. vulnificus are known to be infected to human via fisheries products. Therefore, food safety of fisheries products is important for public health and fish industry. This paper was conducted to know how well these human isolates can survive in olive flounder (Paralichthys olivaceus). The growth of V. parahaemolyticus and V. vulnificus showed about 50~60% reduced rates at 25℃ than at 37℃ and did not show any differences according to NaCl concentration of media except the increasing in the growth of V. vulnificus in medium containing 3% NaCl. Artificial infection of 1×10⁶ CFU/fish was carried out to confirm the sensitivity of olive flounder against V. parahaemolyticus and V. vulnificus. After 1 week from injection, no fish was dead. To evaluate nonspecific defense of olive flounder against V. parahaemolyticus and V. vulnificus, the antibacterial potency of serum and epidermal mucus were tested. The number of the vibrios exposed to serum obtained from olive flounder significantly decreased after 3 hours, and epidermal mucus showed decrease of the bacteria over than 90% until 12 hours from exposure. Phagocytosis of head kidney leucocytes of healthy olive flounder against V. parahaemolyticus and V. vulnificus showed in over 70% of leucocytes at the 2 hours. Therefore, cultured olive flounder only as vehicle for human pathogen in environmental water is well developed its antibacterial potency against human pathogens, so the viability of V. parahaemolyticus and V. vulnificus in cultured olive flounder was considered very low.

• Korean Journal of Culture and Social Issue
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• v.29 no.1
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• pp.53-74
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• 2023

The purpose of this study was to identify the priming effects of disaster-related news. Specifically, this study aimed to examine the priming effects about trauma words and neutral words according to the geographical and psychological distance from the disaster. The participants in this study were 75 college students who had not experienced the Daegu subway fire accident, and whom were not ruled out after completing the screening measure completing the screening measure the completion of questionnaires for screening. All participants conducted a lexical decision task after watching a news video about the Daegu subway fire accident. The design was a 2 (Geographical distance: close vs. distant) × 2 (Psychological distance: close vs. distant) × 2 (Priming type: trauma priming vs. neutral priming) mixed-design. The results of this study are summarized as follows: First, the group which was geographically closer to the disaster tended to revealed a largerbigger priming effect than the distant group-a trend toward significance. Second, within the psychologically closer to the disaster, group, for those who were geographically closer too, the priming effect was larger for those who were geographically closer geographically closer than for the geographically distant group. Third, the geographically closer group had a largerbigger neutral priming effect than the distant group. Fourth, the psychologically distant group had a largerbigger neutral priming effect than the close group. To sum up, this study identified that disaster news coverage may have an implicit effect on people, and this influence can change according to the geographical and psychological distance. Finally, this study discussed the limitations of the study and recommendations for further research.

• Korean Journal of Environmental Biology
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• v.41 no.1
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• pp.41-53
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• 2023

E171, a mixture of titanium dioxide, has been widely used as a food additive due to its whitening effect and low toxicity. However, it has been proven that E171 is no longer safe for public health. So far, there are insufficient studies on the toxic effects of E171 on organisms especially using standardized test methods. In this study, toxicity assessments of E171 to two aquatic species, water flea (Daphnia magna) and zebrafish (Danio rerio), were performed using modified standardized test methods based on the physicochemical properties of E171. The hydrodynamic diameter, polydispersity index, and turbiscan stability index (TSI) were measured to ensure the dispersion stability of E171 in exposure media during the test period. The EC₅₀ for immobilization of water flea was 141.7 mg L^-1 while zebrafish was not affected until 100 mg L^-1 of E171. Measurements of reactive oxygen species (ROS) and antioxidant enzyme activities confirmed that E171 induced oxidative stress, leading to the activation of superoxide dismutase and catalase in both water flea and zebrafish, although the expression of antioxidant enzyme genes differed between species. These results suggested the potential risk of E171 to aquatic organisms and provided toxicological insights into the impacts of E171 on the environment.

• Korean Journal of Animal Reproduction
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• v.24 no.2
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• pp.155-161
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• 2000

The morphological changes on nuclear phase of the germinal vesicle of porcine follicular oocytes during in vitro culture were examined. The high rates (75~77%) of the oocytes collected from follicles of 1~2mm or 6~100mm in diameter were at the GV-I to GV-II stages. When oocytes with or without cumulus cells after collection from follicles of 2~6mm in diameter were cultured for 5 h, the rates of oocytes at GV-IV to GV-Ⅵ stages were higher in oocytes with (52%) than in oocytes without (30%) cumulus cells. After 1 h of oocyte culture, there was no differences in the distribution of GV-IV to GV - Ⅵ stages in the media with or without catalase, xanthine and catalase＋xanthine. After 5 h of culture, however, the distribution of GV-IV to GV-Ⅵ stages were 46, 69, 69 and 70% for medium with none, catalase, xanthine and catalase＋xanthine. The highest rate of GVBD was also observed in the medium with catalase＋xanthine (6%). These results indicate that exposure of porcine follicular oocytes to catalase＋xanthine excels maturation to GV stage and enhances oocyte nuclear maturation.