• Journal of radiological science and technology
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• v.47 no.3
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• pp.205-211
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• 2024

Currently, with the development of technologies, X-ray examinations for medical examinations at hospital is increasing. This study was conducted to help reduce radiation exposure by measuring the exposure dose received by pediatric patients and the spatial dose of the X-ray room. Dosimeters were installed in the eyeball, thyroid gland, breast, gonads and 4 directions at a distance of 30 cm, 40 cm, 50 cm from the phantom. The dose was measured ten times each, before, and after the application of the bismuth shield under the examination conditions of the head, chest, and abdomen of pediatric patients. Under the condition of head examination, when a shielding was applied, the dose reduction rate was 68.58% for the eyeball, 72.88% for the thyroid, 84.2% for the breast, and 72.36% for the gonad. The chest examination showed reductions of 19.56% eyeball, 56.98% thyroid, 1.21% breast, and 0.68% gonad. The abdominal examination showed reduction rates of 2.6% eyeball, 10.67% thyroid, 19.85% breast, and 82.02% gonad. Spatial dose decreased by 62.25% at 30 cm, 61.16% at 40 cm, and 68.68% at 50 cm. When the bismuth shield was applied, there was a decrease in dose across all examinations, as well as a reduction in spatial dose. Continued research on the use of bismuth shields will help radiological technologists achieve their goal of dose reduction.

• Food Science and Preservation
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• v.31 no.2
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• pp.307-314
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• 2024

Broussonetia kazinoki twig extract (BKT) is recognized for its antioxidant and anti-cancer effects and natural whitening properties. So, it is used as a raw material for cosmetics. B. kazinoki twig is also an edible raw material. B. kazinoki has been used in Asia for paper production and oriental medicine, has anti-diabetic effects, and contains various flavonoids and alkaloids. In this study, to evaluate the efficacy of BKT on allergic skin inflammatory responses, we investigated its effects on factors related to skin inflammation in HaCaT keratinocytes and allergic responses in RBL-2H3 cells. There was no cytotoxicity of the 70% ethanol extract against HaCaT and RBL-2H3 cells. In HaCaT cells, stimulation with tumor necrosis factor-alpha (TNF-𝛼) and interferon-gamma (IFN-𝛾) increased the production of several chemokines, including thymus and activation-regulated chemokine (TARC), macrophage-derived chemokine (MDC), and regulated on activation, normal T cell expressed and secreted (RANTES). However, it was observed that this elevation was notably mitigated in a concentration-dependent manner upon treatment with BKT. Furthermore, BKT treatment demonstrated a significant reduction of 𝛽-hexosaminidase and inflammatory cytokines TNF-𝛼 and IL-4 in IgE-sensitized RBL-2H3 cells. Thus, it is expected that BKT can be used as a natural cosmetic and food ingredient that effectively suppresses allergic inflammatory reactions.

• Journal of The Korean Association For Science Education
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• v.44 no.1
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• pp.77-86
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• 2024

This study analyzed students' discourse and learning to investigate the impact of using Google Docs in science classes. The researcher, who is also a science teacher, conducted classes for 49 second-year middle school students. The classes included one using Google Docs and another using traditional paper worksheets covering identical content. Students' discourse collected from each class was compared and analyzed using Epistemic Network Analysis (ENA). The findings indicated that in the class using Google Docs, the proportion of discourse related to task was higher compared to the traditional class. More specifically, discourse regarding taking and uploading photos was prominent. However, such discourse did not lead to peer learning as intended by the teacher. An analysis based on achievement levels revealed that the class utilizing Google Docs had a relatively higher proportion of discourse from lower-achieving students. Additionally, differences were observed in the types of utterances and connection structures between the higher and lower-achieving students. The higher-achieving students took a leading role in providing suggestions and explanations, while the lower-achieving students played a role in transcribing them, with this tendency being more pronounced in the class using Google Docs. Lastly, students' changes in perception regarding the cause of static electricity were visualized using ENA. Based on the research findings, this study proposes strategies to enhance collaborative learning using Google Docs, including the use of open-ended problems to allow diverse opinions and outputs, and exploring the potential use of ENA to assess the learning effects of conceptual learning.

• Journal of The Korean Association For Science Education
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• v.44 no.2
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• pp.141-153
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• 2024

The 2022 revised science curriculum aims to develop the ability to solve scientific problems arising in daily life and society based on convergent thinking stimulated through participation in research activities using artificial intelligence (AI). Therefore, we developed a science-AI convergence education program that combines the science curriculum with artificial intelligence and employed it in convergence classes for high school students. The aim of the science-AI convergence class was for students to qualitatively understand the movement of a damped pendulum and build an AI model to predict the position of the pendulum using the block coding platform KNIME. Individual in-depth interviews were conducted to understand and interpret the learners' experiences. Based on Giorgi's phenomenological research methodology, we described the learners' learning processes and changes, challenges and limitations of the class. The students collected data and built the AI model. They expected to be able to predict the surrounding phenomena based on their experimental results and perceived the convergence class positively. On the other hand, they still perceived an with the unfamiliarity of platform, difficulty in understanding the principle of AI, and limitations of the teaching method that they had to follow, as well as limitations of the course content. Based on this, we discussed the strengths and limitations of the science-AI convergence class and made suggestions for science-AI convergence education. This study is expected to provide implications for developing science-AI convergence curricula and implementing them in the field.

• Journal of Space Technology and Applications
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• v.3 no.4
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• pp.333-341
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• 2023

This study aims to develop technology for testing and verifying the space radiation environment of miniature space components using the facilities of the domestic 100 MeV proton accelerator and the Space Component Test Facility at the Space Testing Center. As advancements in space development progress, high-performance satellites increasingly rely on densely integrated circuits, particularly in core components components like memory. The application of semiconductor components in essential devices such as solar panels, optical sensors, and opto-electronics is also on the rise. To apply these technologies in space, it is imperative to undergo space environment testing, with the most critical aspect being the evaluation and testing of space components in high-energy radiation environments. Therefore, the Space Testing Center at the Korea testing laboratory has developed a radiation testing device for memory components and conducted radiation impact assessment tests using it. The investigation was carried out using 100 MeV protons at a low flux level achievable at the Gyeongju Proton Accelerator. Through these tests, single event upsets observed in memory semiconductor components were confirmed.

• Food Science and Preservation
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• v.31 no.4
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• pp.601-611
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• 2024

The objective of this study was to integrate onion juice into traditional Korean soy sauce and to evaluate the sterilization conditions necessary for commercialization. As the sterilization temperature increased, pH decreased and titratable acidity increased. A reduction in °Brix was observed post-sterilization, from 37.37 °Brix in untreated soy sauce to 36.67-36.77 °Brix. In terms of chromaticity, the L value declined over the storage period while the a and b values increased. The quercetin component exhibited light sensitivity, with no significant difference observed in the sample on the 60th day. Neither Bacillus cereus nor Clostridium perfringens were detected, and the total bacterial count was comparable to that of commercially available soy sauce. This indicates that samples sterilized at 85℃ for 30 minutes fall within a safe quality range. Sensory evaluation revealed that samples sterilized at 85℃ for 30 minutes exhibited consistently high ratings.

• Journal of Christian Education in Korea
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• v.75
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• pp.59-81
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• 2023

Purpose of study: The purpose of this study is to analyze the experience of writing a learning reflection journal, identify the effects, and propose an effective learning reflection journal activity way. Research content and method: This study examined the theoretical background of the concept and educational effect of the learning reflection journal through literature review in terms of educational and Christian educational aspects, and analyzed the learning reflection journal experience through the interviews with six students. Through this, this study identifies the effectiveness of the learning reflection journal and suggests effective learning reflection journal activity way that can be applied to training that can grow as a Christian educator who practices what he or she know through major classes. Conclusions and Suggestions: For effective learning reflection journal activities, it was proposed to reduce the number of review and reflection questions so that they would not be burdensome, to include questions in a balanced way, to help learners to improve class attitudes. It was also proposed that the submission period and the number of writing journals should be agreed upon with the students at the beginning of the semester.

• Industry Promotion Research
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• v.9 no.3
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• pp.251-261
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• 2024

The purpose of this study is to improve welfare services for the socially underprivileged, the disabled, by improving and streamlining the work environment of workers at day care facilities for the disabled. The research question consisted of three issues: conflict between employees, psychological exhaustion, and growth factors experienced as a Christian worker at a day care facility for the disabled. As a research method, from January 2024 to April 2024, 10 Christian workers working at a day care facility for the disabled were interviewed and collected facts about their experiences during the work process using Colaizzi's phenomenological research method. analyzed. According to the research results, the psychological processes experienced by workers are, first, 'conflict' between internal workers in the experience at a day care facility for the disabled, and second, exhaustion, such as symptoms of emotional exhaustion, dehumanization, and decreased sense of accomplishment, experienced by workers in 'burnout'. It was a traumatic experience. Third, in 'growth', workers overcame internal conflict and psychological exhaustion through spirituality and experienced growth with a sense of stability. This study is expected to provide useful data to improve the morale and work environment of workers at day care facilities for the disabled in the future.

• Journal of Christian Education in Korea
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• v.78
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• pp.87-110
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• 2024

The purpose of this study is to explore the educational philosophy that is the basis for the establishment of Christian alternative schools and the curriculum that is the standard for educational practice accordingly, and to understand in depth the educational philosophy and curriculum, what characteristics are common in each type in the school field. This study also explored the main factors that lead to educational practice in the curriculum. In order to explore these research questions, this study was conducted using interview that is one of the qualitative studies. The subjects of this study are 16 teachers selected from the three types of Christian alternative schools that exist in Korea. Based on our findings and discussion, this study was presented several suggestions. First, in the reality that parents are sending their children to alternative schools for their faith, school leaders and teachers must practice sincere faith education with deep reflection. Second, in order for Christian alternative schools to fulfill their responsibilities as schools and continue to provide a valuable education, it is necessary to integrate Christian worldviews and academics through cooperation with allied organizations. Third, in order to reduce the burden of parents' excessive educational expenses, there should be a civic effort to request financial support from the nation at least for school operating expenses.

• The Korean Journal of Pesticide Science
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• v.19 no.3
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• pp.230-240
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• 2015

An IOM sampler equipped with glass fiber filter has been recently utilized instead of solid adsorbent, which was used to measure the inhalation exposure of agricultural operator to pesticides. The aim of this study is to validate the efficacy of an IOM sampler by measuring the trapping efficiency and breakthrough using kresoxim-methyl water-dispersible granule and fenthion emulsifiable concentrate. On LC-MS/ MS, minimum detection level was 12.5 pg and method limit of detection was 5.0 ng/mL. Good linearity ($R^2$ > 0.999) for matrix matched standards was obtained. Recoveries of pesticides from glass fiber filter were 102-109% (kresoxim-methyl) and 97-104% (fenthion) while those from XAD-2 resin were 94-98% (kresoxim methyl) and 93-100% (fenthion). Trapping efficiency test was performed with personal air pumps and IOM sampler (glass fiber filter) connected with solid adsorbent (XAD-2 resin) with two types of formulation (solid and liquid) which were diluted by standard rate and sprayed to IOM sampler. Those pesticides were trapped only in glass fiber filter without any breakthrough to solid adsorbent. After spiking of pesticides to glass fiber filter, breakthrough test was carried out with IOM sampler (glass fiber filter) which was connected with solid adsorbent. As a results, 87-101% of kresoxim-methyl and 96-105% of fenthion remained in spiked glass fiber filter, however, no pesticides were detected in second glass fiber filter and solid adsorbent. In conclusion, IOM sampler which equipped with glass fiber filter can be applied widely for pesticide inhalation exposure study since it has good trapping efficiency and adsorption capacity, regardless of the solid or liquid formulation.