• Ocean and Polar Research
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• v.44 no.4
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• pp.297-310
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• 2022

To understand the chemical composition of aerosols in the Cheju-Korea Straits and their contribution to the ocean by deposition, aerosol samples were collected on board R/V Eardo from November 1997 to May 1999. The average concentrations of Al, NO₃^-, non-sea-salt (nss)-SO₄^2-, and NH₄⁺ in aerosols were 2.19, 5.59, 6.16 and 2.08 ㎍ m^-3, respectively. The Al concentration in the high yellow dust period was about 100 times higher than that in the non-yellow dust period. The concentration ratio of NO₃^-/nss-SO₄^2- ranged between 0.47 and 1.5, indicating that the aerosols in the Cheju-Korea Straits are under the effects of NO_x and SO_x emitted from China, Korea and Japan. The equivalent concentration ratio of [NH₄⁺]/[nss-SO₄^2-+ NO₃^-] with the average of 0.58±0.29 indicates that nss-SO₄^2- and NO₃^- are not neutralized by NH₄⁺. A high activity concentration of ²¹⁰Pb with 1.13-1.23 mBq m^-3 was observed during the high yellow dust period, indicating that ²¹⁰Pb is easily adsorbed in the yellow dust originating from the continent of Asia. The distribution of ⁷Be and NH₄⁺ concentrations showed a strong negative linear correlation during the low yellow dust period, April 1998. The total mineral dust flux in the Cheju-Korea Straits was estimated to be 1.21×10⁶ tons yr^-1, accounting for about 12% of the annual sediment discharge via the Nakdong River. The combined annual deposition of NH₄⁺ and NO₃^- was 0.103 mole N m^-2 yr^-1 was estimated to support 4% of the annual primary productivity in the East China Sea.

• Korean Journal of School Psychology
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• v.18 no.1
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• pp.121-151
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• 2021

This study aimed to identify the factors that helped and hindered secondary school teachers who experienced student suicide using the concept-mapping approach. Seven South Korean middle and high school teachers were interviewed from which 113 core statements were elicited. The participants sorted these core statements into categories by meaning. Multidimensional scaling and hierarchical cluster analysis were conducted to identify the underlying structure of the teachers' experiences. Four hindering factor clusters emerged: (1) regret over failing to prevent the suicide, (2) an apathetic atmosphere in the school, (3) a sense of helplessness related to suicide survivors, and (4) approach-avoidance conflicts related to suicide survivors. Six helpful factor clusters emerged: (1) cooperation and care offered between suicide survivors, (2) focusing on the present, busy life, (3) spiritual activity, (4) social support, (5) overcoming grief through altruistic behaviors, and (6) sympathy for the deceased. Two dimensions were found for both the hindering and helpful factors. The hindering factor dimensions were external system-internal experiences and related to suicide survivors-related to suicide decedents. The helpful factor dimensions were distancing from the loss-approaching the loss and professional activities-personal activities. The present study empirically explored and described the underlying structure of teachers' bereavement experiences after student suicides.

• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.4
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• pp.47-54
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• 2021

In this study, the performance of a honeycomb-type hydrogen oxidation catalyst to remove hydrogen in a hydrogen economy society to secure leaking hydrogen. The Pd/TiO₂ catalyst was prepared based on a liquid phase reduction method that is not exposed to a heat source, and it was showed through H₂-chemisorption analysis that it existed as very small active particles of 2~4 nm. In addition, it was found that the metal dispersion decreased and the active particle size increased as the reduction reaction temperature increased. It was meant that the active metal particle size and the hydrogen oxidation performance were in a proportional correlation, so that it was consistent with the hydrogen oxidation performance reduction result. The prepared catalyst was coated on a support in the form of a honeycomb so that it could be applied to the hydrogen industrial process. When 20 wt% or more of the AS-40 binder was coated, oxidation performance of 90% or more was observed under low-concentration hydrogen conditions. It was showed through SEM analysis that long-term catalytic activity can be expected by enhancing the adhesion strength of the catalyst and preventing catalyst desorption. It is a basic research that can secure safety in a hydrogen society such as gasification, organic resource, and it can be utilized as a system that can respond to unexpected safety accidents in the future.

• Journal of Convergence for Information Technology
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• v.12 no.5
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• pp.237-245
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• 2022

This study examines the social discourse on the characteristics of the learning community in the untact era, and discusses the directions that learning communities for children could explore and consider in the pandemic situation and beyond. For this purpose, big data for one year, from January 20, 2020 to January 20, 2021, were collected through internet portal sites (includingincluding Google News, Daum, Naver and other News surfaces), using two keywords "untact" and "learning community", and analyzed by employing a word frequency and network analysis method. The analysis results show that several important terms, such as 'village education community', 'operation', 'activity', 'corona 19', 'support', and 'online' are closely related to the learning community in the untact era. The findings from this study also have implications for developing the learning community as an alternative model to fill the existing gaps in public care and education for children during the prolonged pandemic and afterwards. In conclusion, the study findings highlight that it is meaningful to identify key terms and concepts through word frequency analysis in order to examine social trends and issues related to the learning community.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.7
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• pp.1011-1022
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• 2021

The Korea Coast Guard(KCG) is the only comprehensive maritime administrative agency in Korea that performs various tasks taking place in the ocean, including rescue operations, disaster management, policing, Drug and smuggling crackdown, responding to Response to invasion of maritime territory, environmental conservation, and maritime security. It is vital to inform the public of the role and mission of KCG as the only comprehensive maritime administrative agency in Korea. However, most citizens, excluding residents of the coastal and island areas, have little knowledge of the security administration services of the KCG due to lack of exposure. This study reviewed the KCG's public relations(PR) organization and current status using KCG promotional materials, diagnosed the actual conditions of KCG's PR, and suggested ways to improve public relations activities through a questionnaire survey of public relations personnel. Through literature research and questionnaire survey, the KCG's public relations status was estimated and the measures to enhance publicity was derived as follows: strengthening the PR organization by reinforcing the personnel in charge of PR, improving customized promotion by clarifying the promotion strategy according to the promotion target, enhancing job training for PR personnel, and increasing the interest and support of commanders and internal members in charge of PR work.

• Applied Chemistry for Engineering
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• v.34 no.4
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• pp.357-364
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• 2023

Selective catalytic reduction (SCR) is the most effective method for reducing nitrogen oxide emissions, but the operating temperature range of V₂O₅-WO₃/TiO₂ catalysts is narrow (300~400℃). In this study, a new catalyst with an operating temperature range of 200~450℃ was developed. The catalyst poison, ammonium bisulfate, generated during the SCR process can be removed by heating above 350℃. To increase the number of active sites and promote the dispersion of active materials, titanium isopropoxide (TTIP) treatment was performed on the TiO₂ support with various TTIP/TiO₂ mass ratios. Among them, the 5 wt% TTIP loaded catalyst showed improved performance due to higher thermal stability caused by high W dispersion and the formation of V⁵⁺. In addition, the 5 wt% TTIP-loaded catalyst prepared by a one-step co-precipitation method showed greater V-OH and W-OH dispersion and enhanced interactions in contrast to conventional methods, resulting in higher catalytic activity at lower temperatures. This review article aims to provide an accessible explanation for researchers investigating how to improve the surface properties of TiO2 catalysts using TTIP.

• Journal of Korea Entertainment Industry Association
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• v.13 no.2
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• pp.207-217
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• 2019

The purpose of this study is to examine the physical and psychological effects of lifelong physical activity and the role of leader capacity, to provide practical basic data on intangible benefits and to suggest ways to activate the value of lifelong physical education. This study was conducted from September 1, 2018 to September 30, 2018, with a total of 206 questionnaires centering on men and women participating in sports in Jeollanam do. The two-step approach proposed by Anderson & Gerbing (1988) was used to examine the structural relationships between physical benefits, social benefits, mental benefits, self efficacy benefits, leisure cultural benefits, physical effects, mental effects, Respectively. The conclusions of this study are summarized as follows. First, physical and leisure cultural benefits have a positive(+) direct effect on leader capacity. Second, self-efficacy benefits, physical benefits, and leisure cultural benefits have positive direct effects on physical effects. Third, self-efficacy and leisure culture benefits have a direct positive effect on mental effects. Fourth, leadership competence plays a mediating role in the relationship between leisure cultural benefits and physical effects. In addition, it has a mediating role in the relationship between leisure cultural benefits and mental effects. In order to maximize the quantitative expansion and qualitative improvement of living sports and to enhance intangible value of participants in sports for all, the private capital investment such as the training of competent leaders, the development of various programs, and the investment support in the public sector, We hope that the role of the new welfare service delivery system shared with welfare will be provided.

• Journal of The Korean Association For Science Education
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• v.43 no.2
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• pp.99-110
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• 2023

In this study, in order to strengthen the AI utilization competency of pre-service secondary science teachers, a project activity in which pre-service teachers directly create an 'AI-based molecular structure customized learning support tool' by using Google's teachable machine was developed and applied. To this end, the program developed for 26 third-grade pre-service teachers enrolled in the Department of Chemistry Education at H University in Chungcheongbuk-do was applied for 14 sessions during extracurricular activities. Then, the perceptions of 'understanding how AI works', 'efficacy of using AI in science classes', and 'plans to utilize AI in science classes' were investigated. As a result of the study, it was found that the program developed in this study was effective in helping pre-service teachers understand the operating principle of AI technology for machine learning at a basic level and learning how to use it. In addition, the program developed in this study was found to be effective in increasing the efficacy of pre-service teachers for the use of AI in science classes. And it was also found that pre-service teachers recognized the aspect of using AI technology as a new teaching·learning strategy and tool that can help students understand science concepts. Accordingly, it was found that the program developed in this study had a positive impact on pre-service teachers' AI utilization competency reinforcement and perception improvement at the basic level. Implications of this were discussed.

• Knowledge Management Research
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• v.24 no.1
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• pp.1-29
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• 2023

The COVID-19 pandemic has accelerated digital transformation across all industries and daily life. Edutech is spreading in the education field, also bringing changes in university education. Non-face-to-face online-only classes at universities have spread after the COVID-19 pandemic physical distancing started. Online-only or real-time online classes showed diverse educational imitations. 'Metaverse' started to attract attention as a learning space and community activity support platform that may solve the limitations of online education and communication. It is time to prepare an introduction strategy for the actual application of education using metaverse. This study, first, by examining previous studies and cases of metaverse application, and second, establishing a metaverse introduction framework based on the technology lifecycle model and the innovation diffusion theory. Finally, we provide an introduction strategy in steps, a specialized introduction plan according to the main users is established and presented as a scenario. We expect that this study will provide the theoretical background of the new technology introduction and the spread of metaverse research. Also, we present an efficient introduction strategy, the basis for a service model, and a practical basis for the university's value-added strategy.

• Journal of Science Education
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• v.46 no.2
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• pp.195-211
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• 2022

In this study, we explored the meaning of astronomical observation activities of five earth science teachers through in-depth interviews. Semi-structured interviews were conducted after providing a questionnaire based on Seidman's three-step process of interview. By analyzing the interview transcript, the educational implications inherent in astronomical observation activities were extracted. Teachers have constructed systematic basis of observation and astronomy in the observational astronomy and laboratory class during their course in the teacher education institute. After they became in-service teachers, practical know-hows of astronomical observation activities in schools were developed with the help of colleagues. By designing and executing astronomical observation activities for students, teachers notice positive changes in the cognitive domain, affective domain, and career perception of the students. Hence, teachers consider that astronomical observation activities have great educational effects. In addition, astronomical activities appear to be very rewarding and satisfying experiences to teachers, by providing opportunities for having pride as an earth science teacher. However, teachers tend to find difficulties in operating astronomical observation activities in fields, due to both internal and external obstacles. It is found that the removal of internal obstacles is more important for teachers to attempt or to continue astronomical observation activities. In this sense, it is necessary to support teachers by providing timely training courses with related content, as well as opportunities to share their experiences within a peer group such as teachers' research society.