• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.6
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• pp.517-534
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• 2021

Hydrogen fuel is emerging as an new energy source to replace fossil fuels in that it can solve environmental pollution problems and reduce energy imbalance and cost. Since hydrogen is eco-friendly but highly explosive, there is a high concern about fire and explosion accidents of hydrogen fueled vehicles. In particular, in semi-enclosed spaces such as tunnels, the risk is predicted to increase. Therefore, this study was conducted on the applicability of the equivalent TNT model and the numerical analysis method to evaluate the hydrogen explosion pressure in the tunnel. In comparison and review of the explosion pressure of 6 equivalent TNT models and Weyandt's experimental results, the Henrych equation was found to be the closest with a deviation of 13.6%. As a result of examining the effect of hydrogen tank capacity (52, 72, 156 L) and tunnel cross-section (40.5, 54, 72, 95 m²) on the explosion pressure using numerical analysis, the explosion pressure wave in the tunnel initially it propagates in a hemispherical shape as in open space. Furthermore, when it passes the certain distance it is transformed a plane wave and propagates at a very gradual decay rate. The Henrych equation agrees well with the numerical analysis results in the section where the explosion pressure is rapidly decreasing, but it is significantly underestimated after the explosion pressure wave is transformed into a plane wave. In case of same hydrogen tank capacity, an explosion pressure decreases as the tunnel cross-sectional area increases, and in case of the same cross-sectional area, the explosion pressure increases by about 2.5 times if the hydrogen tank capacity increases from 52 L to 156 L. As a result of the evaluation of the limiting distance affecting the human body, when a 52 L hydrogen tank explodes, the limiting distance to death was estimated to be about 3 m, and the limiting distance to serious injury was estimated to be 28.5~35.8 m.

• Journal of Korea Entertainment Industry Association
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• v.14 no.1
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• pp.149-158
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• 2020

The purpose of this study was to examine relation of oral health awareness, knowledge and behavior in department dental hygiene, health-related majors and health-unrelated majors in attempt to provide basic data of oral health promotion and oral health education. This study were 591 female H university students in Gwangju. The interests of oral health, the recognition of importance for oral health, and recognition of one's own oral health status were highest in dental hygiene students, followed by health-unrelated majors and health-related majors. The level of oral health knowledge by the major was highest in dental hygiene students(9.73), followed by health-related majors(9.14) and health-unrelated majors(9.05). In the oral health behavior by major, students who brushed more than three times a day, used the oral care products and received regular dental examinations within 1 year were the highest in the dental hygiene major, followed by health-related majors and health-unrelated majors. The experience of scaling within 1 year was the highest in the dental hygiene major, followed by health-related majors and health-unrelated majors. The higher the oral health knowledge, increased awareness of oral health concern and the importance of oral health. Also, the higher the degree of interest in oral health, the greater the recognition that oral health is important and the more the oral health condition is perceived as healthy, It was found that the number of brushing increased. In this results, the higher the oral health knowledge, the higher the oral health awareness and the oral health behavior. It is necessary to find ways to develop or utilize various oral health education for university students.

• Journal of the Korean Society of Floral Art and Design
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• no.45
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• pp.77-95
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• 2021

This study considers the problem of reality that our floral art has to overcome as a loss of the floral art spirit caused by the expansion of Western-centered formalism flower culture, and considers the discussion on the deformality of distancing and the free spirit of nomadism. The floral art, which works on the creator's aesthetic mental world through flowers, is an art of mental image that values the free mental world of the creator. It also refers to the importance of artist consciousness as an art of self-imago that makes the target world beyond the "expression of similarity" that reproduces the target world. In this context, the lack of concern about the identity of Korean floral art appears to be the creative training and work of Korean floral artists who are biased toward Western expression techniques and creative methods. It also expresses a problem with our cultural consciousness, which is dominated by the Western flower culture of flower design. Here, we are obliged to understand the reality of Korean floral art biased by Western flower design and to organize discussions to solve the problem. Therefore, this study examines the problems that our floral art has to overcome as part of seeking the identity of Korean floral art and enhancing the cultural value of Korean floral art through criticism of Western cultural acceptance. This is a historical consideration of the nature of Korean floral art to recover, while also a process of identifying the meaning of the free creative spirit that the artist should maintain as an aesthetic art. Furthermore, such criticism of the Korean floral art culture and discussion of introspection are expected to serve as an opportunity to further expand the academic discourse system for the floral art while embodying the "identity" of Korean floral art.

• Journal of Life Science
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• v.32 no.12
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• pp.919-928
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• 2022

As seen in the COVID-19 pandemic, unexpected emergence of new viruses presents serious concern on public health. Especially, the absence of effective vaccines or antiviral drugs against emerging viruses significantly increases the severity of disease and duration of viral circulation among population. Natural products have served as a major source for safe and effective antiviral drugs. In this study, we examined the virucidal activity of medical herb extracts with a view to discover novel antiviral agents with desired levels of safety and antiviral efficacy. Ethanol extracts of ten selected medical herbs were tested for antioxidant activity and in-vitro cytotoxicity in various animal cell lines. Of note, the herbal extracts showed broad and potent virucidal activities against rotavirus, hepatitis A virus, and influenza A virus. The extracts of Sorbus commixta and Glycyrrhiza uralensis showed strong virucidal activities against influenza A virus. We also examined whether the extracts of Sorbus commixta and Glycyrrhiza uralensis can be used as inactivating agents to prepare an inactivated viral vaccine. In a mouse model, influenza A virus inactivated by the extracts elicited high levels of neutralizing antibodies, and the vaccination provided complete protection against lethal challenge. These results suggest that herb-derived natural products can be developed to antiviral drugs as well as inactivating agents for preparation of inactivated viral vaccines.

• Journal of Korean Home Economics Education Association
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• v.34 no.1
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• pp.35-57
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• 2022

This study developed an 'Eco-friendly Clothing Life Cycle' class applying gamification. And the effect of and learners' satisfaction on the class were examined after implementation. The developed class was applied to 40 sophomore students from "A" high school in Gyeonggi-do from February 3, 2022, to February 10, 2022, in a total of 4 sessions. The class was conducted in the stages of production-distribution-consumption-disposal, and was conducted in a way that a mission is solved after learning in Gather Town. It is designed so that learners continuously repeat learning until they accomplish the mission. The learners completed pre-class and post-class questionnaires. And a focus group interview was conducted with a randomly selected group of three learners. According to the pre-/post-class test comparison, the gamification class on the theme of "Eco-friendly Clothing Life Cycle" was found not to have a significant effect on learners' immersion or self-directed learning attitudes. However, in the case of the learners with high levels of non-immersion tendency, the level of immersion in the class increased, and the satisfaction level was positively associated with the level of immersion and self-directed attitude. Learners expressed 'concern' and 'expectation' about the gamification class, and said that although the developed class was using a 'new teaching method', 'appropriate use' was necessary. And learners were evaluated this class as a 'student-centered class' and acknowledged that it allowed 'self-directed learning'. The teacher who implemented the class said that this class was more effective in attracting students' expectations and interests compared to the conventional classes, and that the class in the meta-verse environment was perceived as a new type of class in the non-face-to-face era. The teacher also mentioned that when applied to the actual educational field, a detailed design is needed that allows the learners to proceed smoothly, and the role of the teacher in the class was more important. And the teacher also mentioned that the class should be properly designed so that the expectations given by the 'game' do not obscure the essence of the class.

• Journal of the Korean Society of Tobacco Science
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• v.24 no.1
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• pp.67-73
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• 2002

In light of addressing consumer health concern, coping with anti-tobacco movement, and promoting new product, tobacco industry is actively pursuing to make a new generation of cigarettes with low tar and nicotine deliveries, and less harmful substances. Low tar and low nicotine cigarettes increases their market shares dramatically world wide, especially in KT&G, multinational tobacco companies, EU countries, even in China regulated by CNTC to set up yearly target to lower tar and nicotine deliveries. On the other hand, to design a new cigarette with reduced harmful substances begins to gain speed. The "modified Hoffmann list" publishes thirty plus substances in tobacco leaf and main smoke stream, which is the prime suspect causing health problems. Various ways and means are developed to reduce such components including new tobacco breeds, new curing method, tobacco leaf treatment before processing, selected filtration system, innovated casing system to reduce free radicals, as well as some non conventional cigarette products. In TSRC held this year, the main topic is related to reduce tobacco specific nitrosamines in tobacco leaf. The new generation of cigarette is in the horizon. It still needs a lot help to produce commercial products with satisfied taste and aroma characters. The flavor industry is not regulated by many governments demanding which ingredients might or might not be for tobacco use. However, most of the cigarette companies self impose a list of ingredients to guide flavor suppliers to design flavors. Unfortunately, the number of ingredients in those lists is getting shorter every year. It is understandable that the health is not the only reason. Some cigarette companies are playing safe to protect the company from potential lawsuit, while others are just copying from their competitors. Moreover, it is obvious that it needs more assistance from casings and flavors to design new generation of cigarettes with missing certain flavor components in tobacco leaf and main smoke stream. These flavor components are either non-existed or at lower level at new form of cured tobacco leaf or filtered in the main smoke stream along with reduced harmful substances. The use of carbon filters and other selected filtration system poses another tough task for flavor system design. Specific flavor components are missing from the smoke analysis data, which brings a notion of "carbon taste" and "dryness" of mouth feel. It is ever more demanded by cigarette industry to flavor suppliers to produce flavors as body enhancer, tobacco notes, salivating agents, harshness reducer, and various of aromatic notes provided they are safe to use. Another trend is that water based flavor or flavor with reduced ethanol as solvent is gaining popularity. It is preferred by some cigarette companies that the flavor is compounded with all natural ingredients or all ingredients should he GMO free. The new generation of cigarettes demands many ways of new thinking process. It is also vital for tobacco industry. It reflects the real needs for the consumers that the cigarette product should be safe to use as well as bearing the taste and aroma characters smokers always enjoyed. An effective tobacco flavor system is definitely a part of the equation. The global trend of tobacco industry is like trends of any other industries lead by consumer needs, benefited with new technology availability, affected by the global economy, and subjected for various rules and regulations. Anti-tobacco organizations and media exceptionally scrutinize cigarette, as a legal commercial product. Cigarette is probably the most studied commercial product for its composition, structure, deliveries, effects, as well as its new developmental trend. Therefore, any new trend of cigarette development would be within these boundaries. This paper is trying to point out what it would be like for tobacco industry in the next few yews and what concerns the tobacco industry. It focuses mostly on the efforts to produce safer cigarettes. It is such a vital task for the tobacco industry and its affiliate industries such as cigarette papers, filters, flavors, and other materials. The facts and knowledge presented in this paper might be well known for the public. Some of the comments and predictions are very much personal opinion for a further discussion.

• Journal of International Area Studies (JIAS)
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• v.14 no.4
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• pp.79-106
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• 2011

The cultural contents industries have moved closer to the centre of the economic action in many countries and across much of the world. For this reason, the concern with the development of glocal cultural contents has also been growing. According to Goldman Sock's BRICs report, Indian economy will be the engine of global economy with China. In addition, India will be a new blue chip country for large consumer market of cultual contents. The most important point for the development of glocal cultural contents is a systematic and in-depth analysis of other culture. India is a complex and multicultural country compared with Korea which is a nation-state. Therefore, this paper is intended as an understanding about India appropriately and suggestion for a strategy to enter cultural industry in India. As the purpose of this paper is concerned, we will take a close look at 9 Indian culture codes which can be classified into three main groups: 1) political, social and cultural codes 2) economic codes 3) cultural contents codes. Firstly, political, social and cultural codes are i) consistent democracy and saving common people, ii) authoritarianism which appears an innate respect for authority of India, iii) Collective-individualism which represents collectivist and individualistic tendency, iv) life-religion, v) carpe diem. Secondly, economic culture codes are vi) 1.2billion Indian people's God which represents money and vii) practical purchase which stands for a reasonable choice of buying products. Lastly, viii) Masala movie and ix) happy ending that is the most popular theme of Masala movies are explained in the context of cultural content codes. In conclusion, 3 interesting cases , , will be examined in detail. From what has been discussed above, we suggest oversea expansion strategy based on these case studies. Eventually, what is important is to understand what Indian society is, how Indian society works and what contents Indian prefers.

• Journal of International Area Studies (JIAS)
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• v.14 no.1
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• pp.277-308
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• 2010

Since the globalization, many changes are occurring in our society. Multicultural phenonmenon in the society is becoming one of our major concern in the Korean society. Thus, this study is focusing on the multicultural phenomenon that we are facing since the globalization in Korea. No doubt that immigration is a growing force influencing the demographics of Korea. Since the mid-1990s, immigrant children and children from mixed marriage have become the fastest growing and the most extraordinarily diverse segment of Korea's child population. Until the recent past, Korea's major social attention has focused on adult immigrants to the neglect of their offspring, creating a profound gap between the strategic importance of the new second generation and the knowledge about its socioeconomic circumstances. In other words, there is a significant lack of studies on children of migrant, particularly from the Muslim background living in Korea. International marriage has grown rapidly in Korea since the late 1990s, and this phenomenon is especially common in rural farming communities. Most brides come from China, followed by Vietnam and other southeast Asian countries. However, there are certain number of Muslim bride coming to Korea. There are about 100 thousand muslim peoples living in Korean society. Among them 2.92% are Muslim immigrants' intermarriage with the Koreans. As a result, there are growing number of muslim brides and bridegroom settling in Korea, which would eventually create muslim families in growing korean multicultural societies. This study specify its research on the muslim mixed family by focusing on the offsprings of the muslim background. Our research team has created the new term on such research subject by using Koslim. Koslim is a 1.5 and 2^nd generation from the Muslim back ground family living in Korea. Thus, the objective of this study is to examine the awareness and the perception of Koslim by the Korean mainstream people. By doing so, it can analyze the general attitude of Koreans towards the Koslim people. In this sense this study intends to play a groundwork to promote successful coexistence between Korean and Koslim. It is anticipated that this research can lay the basis for Koreans to have more open and tolerant attitude towards our new members of society that is increasing everyday.

• Journal of Environmental Impact Assessment
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• v.32 no.2
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• pp.123-133
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• 2023

Wastewater generated in the secondary battery production process contains lithium and high-concentration sulfate. Recently, as demand as demand for high-Ni precursors with high-energy density has surged, nickel emission is also a concern. Lithium and sulfate are not included in the current water pollutant discharge standard, so if they are not properly processed and discharged, the negative effect on future environment may be great. Therefore, in this study, the ecotoxicity of lithium, nickel, and sulfate, which are potential contaminants that can be discharged from the secondary battery production process, was evaluated using water flea (Daphnia magna) and luminescent bacteria (Aliivibrio fischeri). As a result of the ecotoxicity test, 24-hour and 48-hour D. magna EC₅₀ values of lithium were 18.2mg/L and 14.5mg/L, nickel EC50 values were 7.2mg/L and 5.4mg/L, and sulfate EC₅₀ values were 4,605.5mg/L and 4,345.0mg/L, respectively. In the case of D. magna, it was found that there was a difference in ecotoxicity according to the contaminants and exposure time (24 hours, 48 hours). Comparing the EC₅₀ of D. magna for lithium, nickel, and sulfate, the EC₅₀ of nickel at 24h and 48h was 39.6-37.2% compared to lithium and 0.1-0.2% compared to sulfate, which was the most toxic among the three substances. The difference appeared to be at a similarlevelregardless of the exposure time. The EC₅₀ of sulfate was 253.0-299.7% and 639.5-804.6%, respectively, compared to lithium and nickel, showing the least toxicity among the three substances. The 30-minute EC₅₀ values of luminescent bacteria forlithium, nickel, and sulfate were 2,755.8mg/L, 7.4mg/L, and 66,047.3mg/L,respectively. Unlike nickel, it was confirmed that there was a difference in sensitivity between D. magna and A. fischeri bacteria to lithium and sulfate. Studies on the mixture toxicity of these substances are needed.

• Korean Journal of Environmental Biology
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• v.40 no.3
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• pp.316-324
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• 2022

Ethyl formate (EF) is a potent fumigant replacing methyl bromide. The use of EF is limited to a quarantine process. Appling EF to agricultural field as a safe insecticide in greenhouse give us valuable benefits including less residual concern. In this regard, residual pattern after EF fumigation in greenhouse should be undertaken. In the previous study, we have established agricultural control concentration of EF to control pests in a greenhouse. EF was fumigated at 5 g m^-3 level for 2 h. The concentration of EF inside a greenhouse was analyzed to be 4.1-4.3 g m^-3 at 30 min after fumigation. To prepare an analytical method for residues in cucumber crops and soil in the greenhouse, the limit of detection(LOD) of the method was 100ng g^-1 and the limit of quantitation(LOQ) of this method was 300 ng g^-1. R² values of calibration curves for crops and soil were 0.991-0.997. In samples collected immediately after ventilation, EF concentration was determined to be below LOQ level. In addition, EF level was below LOQ in samples collected at 3 h after ventilation except that leaf samples of melon during the flowering period showed a level of 1,068.9 ng g^-1. Taken together, these results indicate that EF used in quarantine can be applied to agricultural fields without residual issue as an effective fumigant for insect pest control.