• Tunnel and Underground Space
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• v.32 no.2
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• pp.160-172
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• 2022

The design regulations for simple explosive storage in Korea only stipulate standards for the materials and thickness of the wall of the structure because the amount of explosives that can be stored is small. There is concern about secondary damage during an internal explosion in a simple storage facility, and it is necessary to reexamine the current standards. The numerical analysis for the TNT 15 kg explosion inside the simple storage was carried out by setting the factors using the robust experimental design method. The displacement of the structure generated under the same time condition was analyzed, and the contribution was evaluated. The contribution of concrete thickness was the highest, and the contribution of concrete strength and rebar arrangement was lower than that of concrete thickness. The reinforcement diameter contributed extremely little to the displacement. The structural standards of the simple storage that are currently applied are insufficient on blast resistance, and it is necessary to present new design standards. Therefore, the design factor to be applied later analysis and actual experiments were taken into consideration. For the design variables, the thickness of the concrete was 15 cm considering the displacement, the concrete strength was selected as general concrete considering the inlet discharge pressure, the factor with the lowest average displacement was selected for the reinforcement arrangement and the diameter of the reinforcement, the factor with the smallest level was selected in consideration of economic feasibility because the difference in displacement was low.

• Journal of Industrial Convergence
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• v.20 no.10
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• pp.87-94
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• 2022

This paper seeks to raise inflection points of battery manufacturing bases in Korea in the V4 region through the reorganization of new industrial technologies in accordance with ESG. As a result, the global supply chain market is cut off. The Russian-Ukraine war and the U.S.-China hegemony are competing in the economic crisis caused by COVID-19. It is showing diversification of new suppliers in an environment where mineral, grain procurement, gas, and even wheat imports from China and Russia are not possible. As a protective glocal, this area is used as a buffer zone(Pro-Russia, Hungary). to an isolated zone(anti-Russia, Poland) by war. In this paper, economic growth is expected to slow further due to the EU tapering period and high inflation in world countries. Due to these changes, the conversion of new tech industry and the contraction of Germany's structure due to energy supply may lose the driving force for economic growth over the past 20 years. This is caused by market disconnection(chasm) in the nominal indicators in this area. On the other hand, Korea should actively develop into the V4 area as an energy generation export (nuclear and electric hydrogen generation) area as a bypass development supply area due to the imbalance in the supply chain of rare earth materials that combines AI. By linking this industry, the energy platform can be scaled up and reliable supply technology (next generation BT, recycling technology) in diversification can be formed in countries around the world. This paper proves that in order to overcome the market chasm caused by the industries connection, new energy development and platform size can be achieved and reliable supply technology (next-generation battery and recycling technology, Low-cost LFP) can be diversified in each country.

• Journal of the Korean Society of Floral Art and Design
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• no.45
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• pp.47-56
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• 2021

It was applied by making the models such as the prior learning (e-learning), modeling by manual, learner's practice, 1:1 teaching coaching, self evaluation, coaching behavior assessment(primary, secondary), and self-directed practice. First, the cognitive practice education through the prior learning is very essential in the practice of floral design. Second, the practice class of floral design is a class where the professor generally set an example first, and the learners followed. Third, this study was to prepare the checklist, reflect it through the self evaluation, and prepare the evaluation form in accordance with the element, principle, and technical parts of floral design about the finished works. Fourth, contrary to the existing class completing within the class hour, the practice class is a process of trying to do self-directed practice, returning to home. Fifth, this study was to evaluate the works the learner made once again through the sketching and photographing by placing the work process of portfolio at the last step. To conclude, this study has found that such series of process through six steps on the practice form by the learner only would be excellent teaching learning model to improving the basic capacity of floral design. Accordingly, the development of teaching materials related to this and adaptation in the field in the future is considered as it will be very helpful to the learners' self-directed learning.

• Communications of Mathematical Education
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• v.35 no.4
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• pp.527-546
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• 2021

The purpose of this study is to reveal what mathematics teachers focus on and how they assess students' thinking during lessons enacted. For this purpose, we googled and searched internet sites to collect formative assessment materials for the year 2014 to 2019. The formative assessment tasks data were analyzed according to the levels cognitive demand levels and tasks suggested in textbooks in terms of degrees to which how they are related. The data analysis suggested as follows: a) most of the formative assessment tasks were at the low-level, in particular, PNC level tasks that require applying particular procedures without connections to concepts and meaning underlying the procedures, b) the assessment tasks appeared to be very similar to the tasks suggested in the secondary mathematics textbooks, and c) it seemed that 3 types of formative assessment, observation notes, self-assessment, and peer-assessment were dominantly utilized during mathematics lessons and these different types of formative assessment were employed apparently to find out whether students participated actively in class and in group activity, not how they go through understanding or thinking processes.

• Journal of the Korean Electrochemical Society
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• v.26 no.1
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• pp.11-18
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• 2023

As the use of lithium-ion secondary batteries is rapidly increasing due to the rapid growth of the electric vehicle market, the disposal and recycling of spent batteries after use has been raised as a serious problem. Since stored energy must be removed in order to recycle the spent batteries, an effective discharging process is required. In this study, graphite and NCM622 were used as active materials to manufacture coin-type half cells and full cells, and the electrochemical behavior occurring during overdischarge was analyzed. When the positive and negative electrodes are overdischarged respectively using a half-cell, a conversion reaction in which transition metal oxide is reduced to metal occurs first in the positive electrode, and a side reaction in which Cu, the current collector, is corroded following decomposition of the SEI film occurs in the negative electrode. In addition, a side reaction during overdischarge is difficult to occur because a large polarization at the initial stage is required. When the full cell is overdischarged, the cell reaches 0 V and the overdischarge ends with almost no side reaction due to this large polarization. However, if the full cell whose capacity is degraded due to the cycle is overdischarged, corrosion of the Cu current collector occurs in the negative electrode. Therefore, cycled cell requires an appropriate treatment process because its electrochemical behavior during overdischarge is different from that of a fresh cell.

• Nutrition Research and Practice
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• v.17 no.2
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• pp.371-385
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• 2023

BACKGROUND/OBJECTIVES: Soy isoflavone (SIF) and soy lecithin (SL) have beneficial effects on many chronic diseases, including neurodegenerative diseases. Regretfully, there is little evidence to show the combined effects of these soy extractives on the impairment of cognition and abnormal cerebral blood flow (CBF). This study examined the optimal combination dose of SIF + SL to provide evidence for improving CBF and protecting cerebrovascular endothelial cells. MATERIALS/METHODS: In vivo study, SIF50 + SL40, SIF50 + SL80 and SIF50 + SL160 groups were obtained. Morris water maze, laser speckle contrast imaging (LSCI), and hematoxylin-eosin staining were used to detect learning and memory impairment, CBF, and damage to the cerebrovascular tissue in rat. The 8-hydroxy-2'-deoxyguanosine (8-OHdG) and the oxidized glutathione (GSSG) were detected. The anti-oxidative damage index of superoxide dismutase (SOD) and glutathione (GSH) in the serum of an animal model was also tested. In vitro study, an immortalized mouse brain endothelial cell line (bEND.3 cells) was used to confirm the cerebrovascular endothelial cell protection of SIF + SL. In this study, 50 µM of Gen were used, while the 25, 50, or 100 µM of SL for different incubation times were selected first. The intracellular levels of 8-OHdG, SOD, GSH, and GSSG were also detected in the cells. RESULTS: In vivo study, SIF + SL could increase the target crossing times significantly and shorten the total swimming distance of rats. The CBF in the rats of the SIF50 + SL40 group and SIF50 + SL160 group was enhanced. Pathological changes, such as attenuation of the endothelium in cerebral vessels were much less in the SIF50 + SL40 group and SIF50 + SL160 group. The 8-OHdG was reduced in the SIF50 + SL40 group. The GSSG showed a significant decrease in all SIF + SL pretreatment groups, but the GSH showed an opposite result. SOD was upregulated by SIF + SL pretreatment. Different combinations of Genistein (Gen)+SL, the secondary proof of health benefits found in vivo study, showed they have effective anti-oxidation and less side reaction on protecting cerebrovascular endothelial cell. SIF50 + SL40 in rats experiment and Gen50 + SL25 in cell test were the optimum joint doses on alleviating cognitive impairment and regulating CBF through protecting cerebrovascular tissue by its antioxidant activity. CONCLUSIONS: SIF+SL could significantly prevent cognitive defect induced by β-Amyloid through regulating CBF. This kind of effect might be attributed to its antioxidant activity on protecting cerebral vessels.

• Geomechanics and Engineering
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• v.32 no.3
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• pp.307-319
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• 2023

Ground fissures have a huge effect on the integrity of surface structures. In high-intensity ground fissure regions, however, land resource would be wasted and city building and economic development would be limited if the area avoiding principle was used. In view of this challenge, to reveal the seismic response and seismic failure characteristics of ground fissure sites, a shaking table test on model soil based on a 1:15 scale experiment was carried out. In the test, the spatial distribution characteristics of acceleration response and Arias intensity were obtained for a site exposed to earthquakes with different characteristics. Furthermore, the failure characteristics and damage evolution of the model soil were analyzed. The test results indicated that, with the increase in the earthquake acceleration magnitude, the crack width of the ground fissure enlarged from 0 to 5 mm. The soil of the hanging wall was characterized by earlier cracking and a higher abundance of secondary fissures at 45°. Under strong earthquakes, the model soil, especially the soil near the ground fissure, was severely damaged and exhibited reduced stiffness. As a result, its natural frequency also decreased from 11.41 Hz to 8.05 Hz, whereas the damping ratio increased from 4.8% to 9.1%. Due to the existence of ground fissure, the acceleration was amplified to nearly 0.476 m/s², as high as 2.38 times of the input acceleration magnitude. The maximum of acceleration and Arias intensity appeared at the fissure zone, which decreased from the main fissure toward both sides, showing hanging wall effects. The seismic intensity, duration and frequency spectrum all had certain effects on the seismic response of the ground fissure site, but their influence degrees were different. The seismic response of the site induced by the seismic wave that had richer low-frequency components and longer duration was larger. The discrepancies of seismic response between the hanging wall and the footwall declined obviously when the magnitude of the earthquake acceleration increased. The research results will be propitious to enhancing the utilizing ratio of the limited landing resource, alleviation of property damages and casualties, and provide a good engineering application foreground.

• Journal of Industrial Convergence
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• v.21 no.3
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• pp.195-202
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• 2023

This study analyzes the results of a survey based on classes conducted in the field to understand the educational needs of learners, and reflects the elements necessary for SW education. In this study, various experimental elements according to learning motivation and learning achievement were constructed and designed through previous studies. As a survey applied to this study, experimental elements in three categories: Faculty Competences(FC), Learner Competences(LC), and Educational Conditions(EC) were analyzed by primary area and secondary major, respectively. As a result of analyzing CT-based SW education by area, the development of educational materials, understanding of lectures, and teaching methods showed high satisfaction, while communication with students, difficulty of lectures, and the number of students were relatively low. The results of the analysis by major were found to be more difficult and less interesting in the humanities than in the engineering field. In this study, Based on these statistical results proposes the need for non-major SW education to improve into an interesting curriculum for effective liberal arts education in the future in terms of enhancing learners' problem-solving skills.

• Journal of the Korea Safety Management & Science
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• v.25 no.2
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• pp.17-28
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• 2023

This study aimed to verify the validity of the evaluation items and weight determination of the indoor environmental safety area, which has the most frequent accidents, among the safety certification evaluations of educational facilities by the Ministry of Education of the Republic of Korea, which has been conducted since May 2021. As a preceding study, the evaluation items of the school safety evaluation checklist being implemented in the US state of Vermont were compared, and the causes of accidents judged by teachers in the accident experiences written by 200 Korean teachers were compared with the safety certification evaluation items belonged to the Ministry of Education. In addition, research literature using the AHP analysis technique on safety risks of elementary and secondary schools in China and safety evaluation index study cases of 539 elementary school children in Indonesia were analyzed. Through these preceding studies, measures to add and adjust evaluation items were derived and the validity and importance rankings of evaluation items were calculated through AHP questionnaires to teachers and safety experts. In addition, a survey was conducted on 104 ordinary people to verify the results of expert analysis. As a result of expert AHP analysis, 'safety education and disaster response training (.396)' was the highest priority for the relative importance of the first layer, followed by 'safety measures (.387)' and 'building materials'. Safety (.216)' was found to be the highest priority. In the overall importance ranking of the 13 second-tier screening items, safety accident prevention education had the highest priority and disaster preparedness training ranked second, proving that the Ministry of Education's review weight was underestimated. In addition, slip and collision accident countermeasures, which were not in the existing Ministry of Education review items, ranked 4th, laboratory practice room safety measures ranked 6th, and sanitation, cleanliness, hazardous substance management, and cafeteria/cooking room safety measures ranked 9th, indicating a significant level of importance. Referring to the importance ranking, which is the result of this study, it is suggested that it is necessary to review the weight of each review item again.

• Journal of Life Science
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• v.33 no.7
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• pp.593-604
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• 2023

The ocean accounts for over 70% of the Earth's surface and is a space of largely unexplored unknowns and opportunities. Korea is a peninsula surrounded by the sea on three sides, emphasizing the importance of marine research. The ocean has an extremely complex environment with immense biological diversity. In terms of microbiology, the marine environment has varying factors like extreme temperature, pressure, solar radiation, salt concentration, and pH, providing ecologically unique habitats. Due to this variety, marine organisms have very different phylogenetic classifications compared with terrestrial organisms. Although various microorganisms inhabit the ocean, studies on the diversity, isolation, and cultivation of marine microorganisms and the secondary metabolites they produce are still insufficient. Research on bioactive substances from marine microorganisms, which were rarely studied until the 1990s, has accelerated in terms of natural products from marine Actinomycetes since the 2000s. Since then, industries for bioplastic and biofuel production, carbon dioxide capture, probiotics, and pharmaceutical discovery and development of antibacterial, anticancer, antioxidant, and anti-inflammatory drugs using bacteria, archaea, and algae have significantly grown. In this review, we introduce current research findings and the latest trends in life science and biotechnology using marine microorganisms. Through this article, we hope to create consumer awareness of the importance of basic and applied research in various natural product-related discovery fields other than conventional pharmaceutical drug discovery. The article aims to suggest pathways that may boost research on the optimization and application of future marine-derived materials.