• Journal of Broadcast Engineering
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• v.27 no.5
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• pp.728-737
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• 2022

Metaverse is gaining worldwide interest, and related industries are developing rapidly. In the field of education, students' interest in metaverse is increasing, and education on metaverse-related technologies and services is required. However, since metaverse classes in universities mainly consist of theoretical education and domestic/overseas case analysis education, practical education that can apply metaverse technology to the real world is also necessary. In the cultural field, event contents such as entrance ceremonies and exhibitions are mainly produced for metaverse contents, and it is also necessary to study metaverse contents that can be sustained for a long time by people visiting regularly. In this study, educational contents that can link cultural participation in the real world with cultural participation in the metaverse were studied using the local cultural space as a medium to produce sustainable metaverse contents. The 'Metaverse Moonshin Art Museum commemorating the 100th anniversary of Moonshin's birth' program reinterpreted the real world of Changwon Moonshin Art Museum into a virtual world by collaborating with students on the Roblox. The 'Expanded Reality Moonshin Art Museum' program created an expanded Metaverse art museum that transcends time by augmenting the deceased Moonshin artist in the museum's exhibition space using HoloLens. For students studying culture-related majors, an educational program that combines metaverse education and practical training was conducted, and it is planned to be supplemented and used as a teaching plan.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.4
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• pp.73-80
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• 2022

This study evaluated changes in fluidity and rheological properties over time for 3D printed composite materials, and evaluated compressive strength and splitting tensile strength properties for laminated and molded specimens. The composite material for 3D printing starts to change rapidly after 30 minutes of extrusion, and the viscosity of the material tends to be maintained up to 90 minutes, but it was confirmed that construction within 60 minutes after mixing is effective. The compressive strength of the laminated test specimen showed equivalent or better performance at all ages compared to the molded test specimen. In the stress-strain curve of the laminated specimen, the initial slope was similar to that of the molded specimen, but the descending slope was on average 1.9 times higher than that of the molded specimen, indicating relatively brittle behavior. The splitting tensile strength of the P-V laminated specimen was about 6% lower than that of the molded specimen. It is judged that this is because the interfacial adhesion force against the vertical load is affected by the pattern direction of the laminated test specimen.

• Korean Journal of Remote Sensing
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• v.38 no.5_3
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• pp.967-977
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• 2022

The occurrence and intensity of wildfires are increasing with climate change. Emissions from forest fire smoke are recognized as one of the major causes affecting air quality and the greenhouse effect. The use of satellite product and machine learning is essential for detection of forest fire smoke. Until now, research on forest fire smoke detection has had difficulties due to difficulties in cloud identification and vague standards of boundaries. The purpose of this study is to detect forest fire smoke using Level 1 and Level 2 data of Geostationary Environment Monitoring Spectrometer (GEMS), a Korean environmental satellite sensor, and machine learning. In March 2022, the forest fire in Gangwon-do was selected as a case. Smoke pixel classification modeling was performed by producing wildfire smoke label images and inputting GEMS Level 1 and Level 2 data to the random forest model. In the trained model, the importance of input variables is Aerosol Optical Depth (AOD), 380 nm and 340 nm radiance difference, Ultra-Violet Aerosol Index (UVAI), Visible Aerosol Index (VisAI), Single Scattering Albedo (SSA), formaldehyde (HCHO), nitrogen dioxide (NO₂), 380 nm radiance, and 340 nm radiance were shown in that order. In addition, in the estimation of the forest fire smoke probability (0 ≤ p ≤ 1) for 2,704 pixels, Mean Bias Error (MBE) is -0.002, Mean Absolute Error (MAE) is 0.026, Root Mean Square Error (RMSE) is 0.087, and Correlation Coefficient (CC) showed an accuracy of 0.981.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.3
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• pp.227-234
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• 2022

In this study, the rheological properties of cement paste composites applied with carbon-based nano-materials were experimental analyzed. Flow table and rheological properties, compressive strength were measured in the cement paste using graphene oxide asqueous solution and carbon nanotube aqueous solution. When carbon nano-materials was mixed in an aqueous solution, flow decreased and plastic viscosity and shear stress were increased. In particular, graphene oxide rapidly increased the plastic viscosity and shear stress. In the case of carbon nanotube aqueous solution, when less than 0.2 % was mixed, the increase rate was low compared to graphene oxide. This is because the specific surface area of graphene, which is in the form of a plate, is large. The compressive strength showed a small amount in strength increase when graphene mix, and CNT had a strength about 112 % of OPC. Carbon-based nanomaterials, is considered that CNT are suitable more to be used construction materials. However, extra studies on the surfactant to be used for mixing proportion and dispersion will be needed.

• Journal of Bio-Environment Control
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• v.30 no.3
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• pp.218-229
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• 2021

Recently, as consumers' interest and importance in health care have significantly increased, they prefer natural and organic foods that do not use chemical pesticides. Since sprout vegetables effectively promote health and prevent diseases such as cancer and cardiovascular disease, the consumption of sprout vegetables, a highly functional and safe food, has been increased significantly. This study aimed to investigate the effect of light on the growth and bioactive compounds of seven different sprout vegetables. After sowing the seeds of various sprout vegetables (kale, Chinese kale, broccoli, red cabbage, alfalfa, red radish, and radish), the sprouts were cultivated under light conditions (20℃, RGB 6:1:3, 130 μmol·m^-2·s^-1, 12 hours photoperiod) and dark condition for 7 days. Sprouts samples were taken at 1-day intervals from 4 to 7 days after treatment. The fresh weight, dry weight, plant height, total phenol content, and antioxidant capacity were measured. Brassica species (kale, Chinese kale, broccoli, red cabbage) and Medicago species (alfalfa) had significantly higher fresh weight values under dark conditions, while the content of bioactive compounds was increased considerably under light conditions. In contrast, the fresh weight of Raphanus genus (red radish, radish) significantly increased under the light condition, but the antioxidant phenolic compounds were significantly higher under the dark state. A negative correlation was observed between the growth and secondary metabolites in various sprout vegetables. This study confirmed the effect of light and dark conditions on different sprout vegetables' growth and nutritional value and emphasizes the importance of harvest time in producing high-quality sprout vegetables.

• Journal of the Korea Convergence Society
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• v.12 no.4
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• pp.267-274
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• 2021

This study used data from the 6rd and 12th year of the Korean Welfare Panel to evaluate the effects of the Personal Assistance Service(PAS) system on the labor market of PAS users' participation. For the purpose of this study, 64 program groups using the Korean PAS and 344 control groups not using the Korean PAS were selected using Caliper matching among the propensity score matching. A chi-square test was used for the difference in characteristics between groups, and a simple difference-in-differences (DID) model and a double-difference multiple regression analysis of DID were performed to estimate the effect of thepolicy before and after the Korean PAS. As a result of the study, it was found that statistically, PAS had no significant effect on the labor market. This is due to the low number of system users, resulting in low post-hoc power, incomplete matching and limited availability of PAS Assistants for Disabled People. Therefore, In order to demonstrate the effectiveness of the Personal Assistance Service(PAS) system, specialized services and systems that meet the needs of the disabled and household members should be implemented.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.6
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• pp.193-198
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• 2021

In this study, the rheological characteristics and of 3D printing composite materials and the compressive strength characteristics according to the lamination patterns were evaluated. As a result of rheology test, rapid material change was observed after 60 minutes of extrusion, yielding stress 1.4 times higher than immediately after mixing, and plastic viscosity was 14.94-25.62% lower. The compressive strength of the specimens manufactured in the mold and the laminated specimens were compared, and the lamination pattern of the laminated specimens were 0°, 45°, and 90° as variables. The compressive strength of the mold casting specimen and the laminated specimen from 1 to 28 days of age showed similar performance regardless of the lamination pattern. In particular, at the age of 28 days, the modulus of elasticity, maximum compressive strength, and strain at maximum stress of all specimens were almost the same. In order to analyze the interface of the laminated specimens, X-ray CT analysis of the specimen whose compressive strength were measured was performed. Through CT analysis, it was confirmed that cracks did not occur at the lamination interface, which can be judged that the interface in the laminated specimen behaved in an integrated manner.

• Journal of the Korean Wood Science and Technology
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• v.32 no.4
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• pp.58-65
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• 2004

This study was performed to investigate the protease activity from fruit body of Sarcodon aspratus and its features. The specific protease activity was increased with the increasing purification steps, 2.62 times by desalting, 17 times by CMC column chromatography, 113.8 times by DEAE-Sephadex A-50 column chromatography, and 728.3 times by Sephadex G-75 column chromatography. Proteases were identified as two different enzymes having different isoelectric points at pH 4.35 (its recovery rate 8%) and pH 4.7 (its recovery rate 3.5%). Those proteases were purified by 3,025 folds and 3,257 folds in terms of specific activity. Two proteases having different isoelectric points had similar enzymatic properties. This protease was estimated to be 43,000 daltons of molecular weights by SDS-PAGE. This protease with optimum pH 4 was almost stable in the pH range of 4~7. Optimal temperature of protease activity was 40 to 50℃, and the protease activity was completely inhibited at 70℃ for 30 min.

• Journal of the Korean Wood Science and Technology
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• v.32 no.5
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• pp.12-19
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• 2004

This study was performed to investigate the optimum condition of protease production from submerged culture of oak mushroom (Lentinula edodes, Sanlim No. 5) and its enzymatic features. Among several combinations of media, the combination of wheat bran, corn flour, water and corn oil (WB+CF+W+ CO) yielded 84.8 U/g of maximum protease activity. This combination of ingredients, in spite of not being particularly protein-rich in comparison to the other media, allowed for good growth of the fungus and maximal protease production. Comparison of different growth medium liquids indicated that demineralized water afforded the best growth of the fungus and the highest protease activity. Acetate buffer and acidified water negatively affected The protease production peaked around 72 hr of incubation, and decreased thereafter. The molecular weights of produced protease were about 45,000 by Sephadex G-75 chromatography. The pH optimum for protease activity was 4, while maximal activity incubated at 37℃ for 1 hr was observed between pH 4~6. The optimum temperature of this protease was 55℃, and the enzyme was active over a broad temperature range (30~60℃), indicating that this protease would be suitable for a wide range of applications where. different pH and temperature are necessary, such as digestive aids, food industry, beer and tannery industries.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.1
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• pp.77-100
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• 2022

In the era of low growth, many provincial cities are experiencing population decline and aging. Population decline phenomena such as reduction of productive manpower, reduction of finances, deterioration of quality of life, and collapse of the community base are occurring in a chain and are being pushed to the brink of extinction of the cities. This study aims to propose a methodology to objectively estimate the employment creation centers and setting the basic unit of industrial-centered zoning by applying spatial statistical techniques and GIS for the application of the compact city plan as an efficient spatial management policy in a city with a declining population. In details, based on reviewing previous studies on compact city, 'employment complex index(ECI)' were defined considering the number of workers, the number of settlers, and the area of development land, the employment creation center was estimated by applying the 'Local Moran's I' and 'Getis-Ord's Hot-Spot Analysis'. As a case study, changes in the four years of 2013, 2015, 2017, and 2019 were compared and analyzed for Changwon City. As a result, it was confirmed that the employment creation center is becoming compacted and polycentric, which is a significant result that reflects the actual situation well. This results provide the basic data for functional and institutional territorial governance for the regional revitalization platform, and provide meaningful information necessary for spatial policy decision-making, such as population reduction, regional gross domestic product, and public facility arrangement that can respond to energy savings, transportation plans, and medical and health plans.