• Journal of Korean Society of Forest Science
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• v.111 no.4
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• pp.644-650
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• 2022

Aralia elata (Miq.) SEEM is a deciduous shrub that has attracted attention as a high-income forest product. To improve the efficiency of cultivation and increase income, productivity according to the pruning period and annual pruning after harvesting Aralia elata shoots was analyzed. The optimal time was determined by pruning five times at 2-week intervals from 6 days after shoot harvesting. To investigate the pruning effect, pruning was performed at 30 cm from the ground in the first year after planting. From the second year after planting, branches grown for 1 year were pruned to 10 cm, and the annual shoots and branches were compared. Thenumber of first pruned branches after 6 days was 1.3-2.1 times higher after shoot harvesting than at other times, and the shoot characteristics were 1.2-1.7 times better than those at other periods. The faster the pruning, the better the quality of the harvested shoots. Annual pruning produced high-quality shoots (approximately 1.5 cm in diameter and 16 cm in length) from the second year after planting, and it was possible to increase productivity by inducing generation of branches capable of harvesting shoots. Annual pruning also made it possible to maintain easy shoot harvesting at approximately150 cm. These results showed that it was efficient to perform Aralia elatapruning as early as approximately 6 days after shoot harvesting. Pruning enabled production ofuniform-quality shoots every year and increasedthe yield of the trees.

• Applied Chemistry for Engineering
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• v.33 no.4
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• pp.444-450
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• 2022

The effect of coated polyester (PET) textiles with metal oxide, chitosan, and copper ion on the antibacterial and antiviral activities was evaluated to investigate the applicability of multi-coated PET textiles as antiviral materials. Compared to coated PETs with a single agent, multi-coated PETs reduced the loading amount of coating materials as well as the contact time with bacteria for a bacterial cell number of < 10 CFU/mL, which was not detectable with the naked eyes. Metal oxides generate reactive oxygen species (ROS) such as free radicals by a catalytic reaction, and copper ions can promote contact killing by the generation of ROS. Chitosan not only enhanced antibacterial activities due to amine groups, but enabled it to be a template to load copper ions. We observed that multi-coated PET textiles have both antibacterial activities for E. coli and S. aureus and antiviral efficiency of more than 99.9% for influenza A (H1N1) and SARS-CoV-2. The multi-coated PET textiles could also be prepared via a roll-to-roll coating process, which showed high antiviral efficacy, demonstrating its potential use in air filtration and antiviral products such as masks and personal protective equipment.

• Composites Research
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• v.35 no.2
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• pp.98-105
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• 2022

In this study, polyvinyl alcohol (PVA)/graphene oxide (GO)/iron oxide (Fe₃O₄) magnetic microgels were prepared using a microfluidic approach and the dye adsorption capacity of the microgels was confirmed. The adsorption capacity (q_e) of the gels was evaluated by varying the dye concentration, pH, and contact time with the microgels. The dyes used in this work were methylene blue (MB), crystal violet (CV), and malachite green (MG), and microgels showed the highest adsorption capacity (191.1 mg/g) in methylene blue. The microgels exhibited the highest adsorption capacity in the dye aqueous solution at pH 10 due to the presence of atomic nitrogen ions (N⁺) on the dye molecules. The adsorption isotherm studies revealed that the Langmuir isotherm is the best fit isotherm model for the dye adsorption on the microgels, indicative of monolayer adsorption. The kinetic analysis exhibited that the pseudo-second order model fits better than the pseudo-first order model, confirming that the adsorption process is chemisorption. In addition, the magnetic microgels showed good reusability and recovery efficiency. It was confirmed that the adsorption capacity of the gels maintains more than 70% of the initial capacity after 5 times of cycle experiments.

• Journal of Powder Materials
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• v.29 no.1
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• pp.47-55
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• 2022

Tungsten carbide is widely used in carbide tools. However, its production process generates a significant number of end-of-life products and by-products. Therefore, it is necessary to develop efficient recycling methods and investigate the remanufacturing of tungsten carbide using recycled materials. Herein, we have recovered 99.9% of the tungsten in cemented carbide hard scrap as tungsten oxide via an alkali leaching process. Subsequently, using the recovered tungsten oxide as a starting material, tungsten carbide has been produced by employing a self-propagating high-temperature synthesis (SHS) method. SHS is advantageous as it reduces the reaction time and is energy-efficient. Tungsten carbide with a carbon content of 6.18 wt % and a particle size of 116 nm has been successfully synthesized by optimizing the SHS process parameters, pulverization, and mixing. In this study, a series of processes for the high-efficiency recycling and quality improvement of tungsten-based materials have been developed.

• Journal of Korea Entertainment Industry Association
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• v.14 no.8
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• pp.49-62
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• 2020

Musicals are plays in which songs and dances are closely aligned with the plot development of the play, and songs and dances develop specific situations and a series of events. In particular, songs perform a fuction of causing the significant changes and emotional ventilation and amplification in the play by specifically capturing the goals and actions the characters are aiming for. This paper focuses on the song that takes on the function of the plot deployment, defines songs that embody actions and stories on stage' as 'action songs' and highlights their role and importance. Action Song is not a clearly defined or prescribed term in Musical. However, 'Action Song' is a song about how a character's desire or motivation for action, given as a 'character song' inserted at the beginning of an integrated musical play, provides a conflict that is a central event of action. In other words, 'action song' means a song that organically combines music and narrative by conveying the action on the stage as a song with lyrics. In addition, it is a song that moves the plot forward and contains a series of events or actions that are the material of the plot. This paper is intended to summarize the concept of'Action song which is not well known to us, and to lay the foundation of the stud, learned the concept, function and efficiency by the analyses of script and music of the musical . As a result, action songs accumulate and amplify tension caused by conflicts and induce the audience to immerse in their emotions. At the same time, the action song multiplies fun and interest of the play while the audience's expectation increased for the next scene after the action song and the progression of the play with single action makes the contents of the drama to be understood clearly.

• Journal of the Korean Institute of Gas
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• v.26 no.4
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• pp.41-57
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• 2022

The global demand for carbon neutrality in response to climate change is in a situation where it is necessary to prepare countermeasures for carbon trade barriers for some countries, including Korea, which is classified as an export-led economic structure and greenhouse gas exporter. Therefore, digital transformation, which is one of the predictable ways for the carbon-neutral transition model to be applied, should be introduced early. By applying digital technology to industrial gas manufacturing facilities used in one of the major industries, high-tech manufacturing industry, and hydrogen gas facilities, which are emerging as eco-friendly energy, abnormal detection, and diagnosis services are provided with cloud-based predictive diagnosis monitoring technology including operating knowledge. Here are the trends. Small and medium-sized companies that are in the blind spot of carbon-neutral implementation by confirming the direction of abnormal diagnosis predictive monitoring through optimization, augmented reality technology, IoT and AI knowledge inference, etc., rather than simply monitoring real-time facility status It can be seen that it is possible to disseminate technologies such as consensus knowledge in the engineering domain and predictive diagnostic monitoring that match the economic feasibility and efficiency of the technology. It is hoped that it will be used as a way to seek countermeasures against carbon emission trade barriers based on the highest level of ICT technology.

• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.3
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• pp.127-137
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• 2022

Zirconia is fabricated through various processes. Each element in fabricating process can affect the physical properties of the definitive prosthesis. In particular, both the milling process and the sintering process can affect the final integrity of the zirconia prosthesis. Most of the milling machines adopt the ultra-precision 5-axis machining method, and the results vary depending on which milling method was used and how the milling equipment was managed. Milling blocks are selected according to cutting efficiency and aesthetic reproducibility. The sintering method can affect the grain growth and optical properties, and an accurate evaluation can be made only with additional research on the recent speed sintering procedure. Not only the sintering temperature but also the temperature holding time can affect the quality of definitive prosthesis.

• Korean journal of applied entomology
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• v.61 no.2
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• pp.369-376
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• 2022

Five different methanol extracts of plants were evaluated as a mosquito repellent against Aedes albopictus in nude mice model. The volatile components of plants were analyzed with GC-MS. The effective dose was the highest in Nepeta cataria with 72.9, 83.7, 86.4, and 97.3% efficiencies at 10, 50, 100, and 200 ㎍/mL, respectively. Nepeta cataria, Actinidia polygama, and Artemisia annua extracts were the most effective in duration time test. And there was no difference compared to negative control in the low mosquito repellent efficiency from 30 minutes. As a result of analyzing the volatile components of each plant, a total of 28 components in Mentha suaveolens, 19 components in Actinidia polygama, 27 components in Artemisia annua, 26 components in Nepeta cataria, and 19 components in Taraxacum platycarpum were detected. Especially, nepetalactone known as an effective ingredient of a mosquito repellent was identified (27.95 mg/Kg) in one of volatile components of Nepeta cataria. Overall, our results provide the possibility to develop mosquito repellents material using natural plants which contain various volatile components.

• Atmosphere
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• v.31 no.5
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• pp.625-635
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• 2021

South Korea established the 2050 Carbon Neutral Plan in response to the climate crisis, and to achieve this policy, it is very important to monitor domestic carbon emissions and atmospheric carbon concentration. Both CO₂ and CO are emitted from fossil fuel combustion processes, but the relative ratios depend on the combustion efficiency and the strength of local emission regulations. In this study, the relationship between CO₂ and CO was analyzed using ground observation data for the period of 2018~2020 at Anmyeon-do site and the CO/CO₂ ratio according to regional origin during high CO₂ cases was investigated based on the footprint simulated from Stochastic Time-Inverted Lagrangian Transport (STILT) model. CO₂ and CO showed a positive correlation with correlation coefficient of 0.66 (p < 0.01), and averaged footprints during high CO₂ cases confirmed that air particles mainly originated from eastern and north-eastern China, and inland of Korean Peninsula. In addition, it was revealed that among the cases of high CO₂ concentration, when the CO/CO₂ ratio is high, the industrial area of eastern China is greatly affected, and when the ratio is low, the contribution of the domestic region is relatively high. The ratio of CO₂ and CO in this study is significant in that it can be used as a useful factor in determining the possibility of domestic and foreign origins of climate pollutants.

• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.279-284
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• 2022

As a study of the blended learning method on design education through the blended learning method, I would like to propose that more advanced learner-led customized design education is possible. Understanding in face-to-face classes and advantages in non-face-to-face classes can be supplemented in an appropriate way in remote classes. Advanced artificial intelligence and big data technology can provide personalized and subdivided learning materials and effective learning methods tailored to learners' levels and interests based on quantified data in design classes. In this paper, it was proposed to maximize the efficiency of the class by applying a method that exceeds the limitations of time and space through the proposal of the A La Carte model (A La Carte). It is a remote class that can be heard anytime, anywhere, and it is also possible to bridge the educational quality and educational gap provided to students living in underprivileged areas. As the goal of fostering creative convergence-type future talents, it is changing with a rapid technological development speed. It is necessary to adapt to the change in learning methods in line with this. An analysis of the infographic virtual space design and construction process through the A La Carte model (A La Carte) proposal was presented. Rather than simply acquiring knowledge, it is expected that knowledge can be sorted, distinguished, learned, and easily reborn with its own knowledge.