• Journal of Environmental Health Sciences
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• v.48 no.4
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• pp.236-243
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• 2022

Background: In the case of multiple exposures to different types of heavy metals, such as the conditions faced by residents living near a smelter, it would be preferable to group hazardous substances with similar characteristics rather than individually related substances and evaluate the effects of each group on the human body. Objectives: The purpose of this study is to evaluate the utility of factor analysis in the assessment of health effects caused by exposure to two or more hazardous substances with similar characteristics, such as in the case of residents living near a smelter. Methods: Heavy metal concentration data for 572 people living in the vicinity of the Janghang smelter area were grouped based on several subfactors according to their characteristics using factor analysis. Using these factor scores as an independent variable, multiple regression analysis was performed on health effect markers. Results: Through factor analysis, three subfactors were extracted. Factor 1 contained copper and zinc in serum and revealed a common characteristic of the enzyme co-factor in the human body. Factor 2 involved urinary cadmium and arsenic, which are harmful metals related to kidney damage. Factor 3 encompassed blood mercury and lead, which are classified as related to cardiovascular disease. As a result of multiple linear regression analysis, it was found that using the factor index derived through factor analysis as an independent variable is more advantageous in assessing the relevance to health effects than when analyzing the two heavy metals by including them in a single regression model. Conclusions: The results of this study suggest that regression analysis linked with factor analysis is a good alternative in that it can simultaneously identify the effects of heavy metals with similar properties while overcoming multicollinearity that may occur in environmental epidemiologic studies on exposure to various types of heavy metals.

• Journal of Korean society of Dental Hygiene
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• v.22 no.5
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• pp.323-332
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• 2022

Objectives: This study aims to confirm the educational necessity and utilization of VR media. And it was conducted to prepare basic data necessary for the use of VR in various dental hygiene education in the future and the development of innovative practical training courses. Methods: Before and after using VR in oral radiology practice classes, learning interest (4 items), learning commitment (9 items), learning motivation (5 items), educational media preference (4 items), and satisfaction (10 items) were investigated and analyzed. Friedman two way ANOVA by ran a nonparametric analysis corresponding to repeated measures ANOVA was performed. The statistical significance level was 0.05. Results: It was found that there were statistically significant differences in learning interest, learning immersion, and learning motivation according to the type of oral radiology practice education medium (p<0.05). Conclusions: VR is expected that the use of learning media using VR will lead to students' interest, immersion, and learning motivation in class, and that positive learning effects on VR education media can be sufficiently obtained.

• Advanced Industrial SCIence
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• v.2 no.3
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• pp.22-28
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• 2023

In this study, we conducted research on the automated trading of U.S. stocks through a volatility strategy using the Fear and Greed index. Volatility in the stock market is a common phenomenon that can lead to fluctuations in stock prices. Investors can capitalize on this volatility by implementing a strategy based on it, involving the buying and selling of stocks based on their expected level of volatility. The goal of this thesis is to investigate the effectiveness of the volatility strategy in generating profits in the stock market.This study employs a quantitative research methodology using secondary data from the stock market. The dataset comprises daily stock prices and daily volatility measures for the S&P 500 index stocks. Over a five-year period spanning from 2016 to 2020, the stocks were listed on the New York Stock Exchange (NYSE). The strategy involves purchasing stocks from the low volatility group and selling stocks from the high volatility group. The results indicate that the volatility strategy yields positive returns, with an average annual return of 9.2%, compared to the benchmark return of 7.5% for the sample period. Furthermore, the findings demonstrate that the strategy outperforms the benchmark return in four out of the five years within the sample period. Particularly noteworthy is the strategy's performance during periods of high market volatility, such as the COVID-19 pandemic in 2020, where it generated a return of 14.6%, as opposed to the benchmark return of 5.5%.

• Analyses & Alternatives
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• v.7 no.2
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• pp.79-110
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• 2023

The purpose of this research is to explore the relation between Brexit and division in various areas within the British society. This research can lead to understanding how division of the British society and the decision of Brexit was mutually influenced. The UK's withdrawal from the EU has been explained mainly through the relations between the EU and the UK; therefore, issues of immigration, EU regulation, and the UK's EU rebate are considered as major reasons. In addition, 'British identity' or 'British exceptionalism' existing in the British society and politics for a long time has been regarded as a reason for Brexit. Although it is generally accepted that Brexit results in the division in the British society, the reasons mentioned above have limitation to explain the result of referendum and the division of the British society in the post-Brexit era. In this sense, this research explores the division in various areas - generation, social grade including income and education level, value and region, etc. - revealed in the British society is not the result of Brexit; rather, this research argues division deeply rooted in the British society before referendum is the root cause of Brexit. The division in various areas immanent in the British society for a long time is complicatedly intertwined, and the decision on Brexit by referendum has led to solidifying the division of the British society. Having considered this division in the British society has been expanded to rancour, it is necessary for the UK to establish appropriate policies for national cohesion.

• Journal of Korean Dental Hygiene Science
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• v.5 no.2
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• pp.97-104
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• 2022

Background: Due to the declining number of students preparing for university entrance exams , the quota of universities has been decreasing continuously. This situation became increasingly diverse as new media used online, mobile, and PR tools to continuously invite students. This study is aimed at offering the helpful data to plan an effective PR strategy by analyzing the correlation between the major selection and satisfaction of the department's social media usage among freshmen majoring in dental hygiene. Methods: The collected data from the self-reported survey with freshmen were analyzed using the SPSS 22.0 program. The survey items were motive to select the major, social media platform that subjects used, reasons to use the media, time to visit the department's social media platform, and satisfaction level on the department's social media platform, using a 5-point Likert Scale. Results: The reasons for choosing a major were given by 32.2% and 15.9% respondents, respectively, as the vision after graduation and practice facilities. 39.9% and 31.4% used Instagram and YouTube for social media platforms, respectively, for using social media platform; 26.9% and 26.3% visited the department's social media before and after entering the university, respectively; 46.4% and 24.9% used Instagram and YouTube for department social media; and they generally satisfied with the contents of the department's social media. 40.9% of them said that information from the department's social media was useful. 33.8% of them said the information from the department's social media exceeded their expectations. 46.8% of them answered that the department's social media made the department's image positive. 33.4% got interested in the major more due to the department's social media. According to 32.1% of respondents, the department's social media was helpful in deciding on a major. With 35.4%, a positive correlation was discovered between the department's practice facilities and satisfaction on the department's social media. Conclusion: It is thought that the department's social media should try continuously by uploading the contents to meet the users' needs on a regular basis and seeking the plans to be able to collect various opinions using surveys through the related social media so that students can select the major and, moreover, lead the positive direction to adapt the university life under the unfamiliar environment after admission.

• Journal of the Korea Society of Computer and Information
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• v.28 no.8
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• pp.175-186
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• 2023

In this paper, we aim to build a gentrification analysis model and examine its characteristics, focusing on the point at which rents rose sharply alongside the recovery of commercial districts after the gradual resumption of daily life. Recently, in Korea, the influence of social distancing measures after the pandemic has led to the formation of small-scale commercial districts, known as 'hot places', rather than large-scale ones. These hot places have gained popularity by leveraging various media and social networking services to attract customers effectively. As a result, with an increase in the floating population, commercial districts have become active, leading to a rapid surge in rents. However, for small business owners, coping with the sudden rise in rent even with increased sales can lead to gentrification, where they might be forced to leave the area. Therefore, in this study, we seek to analyze the periods before and after by identifying points where rents rise sharply as commercial districts experience revitalization. Firstly, we collect text data to explore topics related to gentrification, utilizing LDA topic modeling. Based on this, we gather data at the commercial district level and build a gentrification analysis model to examine its characteristics. We hope that the analysis of gentrification through this model during a time when commercial districts are being revitalized after facing challenges due to the pandemic can contribute to policies supporting small businesses.

• (The) Research of the performance art and culture
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• no.41
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• pp.69-92
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• 2020

This study describes the impact of early childhood teacher's artistic competence on art education pedagogy and improved curriculum design. Furthermore, the effect of drama as a way of improving early childhood teacher's artistic competence is explained. Many researchers have mentioned that early childhood is a period of sensitivity and potential. Therefore, it will be helpful if children meet a teacher who understands them and inspires their innate artistic sense at a level of their eyes. It explained which aspect of artistic competence should be focused for the teacher training education. There are many approaches to develop early childhood teachers' artistic competence. Adopting drama is one of them. The strong points of drama to improve their artistic competence are as follows. Firstly, human's movement and voice are the main artistic channel in drama. What we are doing in daily life is found are drama world. It means if early childhood teachers experience drama activity, they will feel more comfortable and intimate with it. In addition, early childhood teachers tend to be familiar with dramatic play, so they can more easily access to drama world. Secondly, drama will be helpful to understand different feelings and to broaden and deepen understandings of others' standpoints. For early childhood teachers, drama activity will be helpful to understand how dramatic art form works and to lead children's play in diversified and sincere way. In addition, drama activity will be useful to build horizontal and democratic relationships between children and the teacher. It is one of the main emphases of 2019 revised Nori national curriculum. To sum up, drama will be a excellent method to develop artistic competence for early childhood teachers. Thus, it is expected that They have more opportunities to experience drama as an art form.

• Fisheries and Aquatic Sciences
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• v.25 no.12
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• pp.626-636
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• 2022

Shellfish are exoskeleton-bearing aquatic invertebrates that consume various organic and inorganic substances floating in seawater through filter feeding. Heavy metals are known as absorbed and accumulated in seawater. Some of the toxic heavy metals are highly accumulated in seawater, and exposure to them can cause a variety of risks to the human body. Since Koreans like to eat seafood, they are more likely to be exposed to contaminated seafood with heavy metals. In this study, nine types of heavy metals were analyzed on ten different shellfish species in the coastal area of South Korea. The risk assessment was also done on shellfish in which heavy metals were detected. Zinc (Zn) and copper (Cu) were identified at an average of 56.7 mg/kg (6.70 to 466 mg/kg) and 13.2 mg/kg (0.064 to 143 mg/kg), respectively. Lead (Pb) average of 0.208 mg/kg (0.000750 to 1.02 mg/kg), cadmium (Cd) average of 0.454 mg/kg (0.0388 to 1.56 mg/kg) and mercury (Hg) average of 0.0266 mg/kg (0.00548 to 0.174 mg/kg) were identified. Additionally, arsenic (As), chromium (Cr), nickel (Ni), and silver (Ag) were also identified as average concentrations of 4.02 (0.460 to 15.0 mg/kg), 0.167 (< limit of quantification [LOQ] to 0.820 mg/kg), 0.281 (< LOQ to 1.46 mg/kg), and 0.158 mg/kg (< LOQ to 1.15 mg/kg). The result indicates that the monitoring results of heavy metals in most shellfish satisfied the Korean standard. However, Pb and Cd have exceeded some foreign standards, such as the United States and the EU. The permissible human exposure calculated using the heavy metal intake and detection amount was lower than the Joint FAO/WHO Expert Committee on Food Additives human safety standard, and the risk of heavy metals from shellfish consumption was at an acceptable level.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.1
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• pp.15-22
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• 2022

Procalcitonin (PCT) can provide an experimental rationale and a diagnostic lead to distinguish between bacterial and viral infections. This study sought to investigate the clinical characteristics and prognosis of patients with high PCT levels, to improve clinical diagnosis, and to determine whether PCT levels were associated with the subsequent development of sepsis in the general population. This was a retrospective observational study conducted on outpatients (N=127) over a year. The general data and laboratory parameters studied were PCT, C-reactive protein (CRP), and complete blood count (CBC). The positive rates of CRP and white blood cells (WBCs) in the elevated PCT group were higher than those of the normal group (P<0.05); the specificity and sensitivity of the PCT levels were obviously higher than those of the CRP and WBC levels at diagnosis (P<0.05). The mean PCT levels in the low group were significantly higher than those in the high or moderate group (P<0.001). There was a significant positive correlation with CRP, total WBCs, and neutrophils (P<.001). The main finding of this study was the significant association between an elevated PCT level and CRP and WBC levels, signifying a high diagnostic value. This has important implications for the diagnosis of bacterial infections and therapeutic implications for the use of antibiotic treatment in specific patients.

• Journal of the Korean institute of surface engineering
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• v.56 no.3
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• pp.192-200
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• 2023

Graphene, a two-dimensional material, has shown great potential in a variety of applications including microelectronics, optoelectronics, and graphene-based batteries due to its excellent electronic conductivity. However, the production of large-area, high-quality graphene remains a challenge. In this study, we investigated graphene growth on electrolytic copper foil using thermochemical vapor deposition (TCVD) to achieve a similar level of quality to the cold-rolled copper substrate at a lower cost. The combined effects of pre-annealing time, graphenized temperature, and partial pressure of hydrogen on graphene coverage and domain size were analyzed and correlated with the roughness and crystallographic texture of the copper substrate. Our results show that controlling the crystallographic texture of copper substrates through annealing is an effective way to improve graphene growth properties, which will potentially lead to more efficient and cost-effective graphene production. At a hydrogen partial pressure that is disadvantageous in graphene growth, electrolytic copper had an average size of 8.039 ㎛², whereas rolled copper had a size of 19.092 ㎛², which was a large difference of 42.1% compared to rolled copper. However, at the proper hydrogen partial pressure, electrolytic copper had an average size of 30.279 ㎛² and rolled copper had a size of 32.378 ㎛², showing a much smaller difference of 93.5% than before. This observation suggests this potentially leads the way for more efficient and cost-effective graphene production.