• Industry Promotion Research
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• v.6 no.3
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• pp.59-70
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• 2021

The purpose of this study is to analyze the impact of childcare teachers' professionalism on job performance, enhance the effectiveness of childcare teachers, and provide basic data to help them satisfy their duties. Statistical processing of the collected data has been studied through the SSPPWIN 21.0 program, level of expertise, understanding, skills, and attitude recognized by child care teachers, the higher the level of professionalism, the higher the age, educational background, and experience, the higher the level of expertise. In addition, various policy and institutional support at the level of childcare-related administrative agencies or local governments is needed to develop operational measures suitable for each type of daycare center and improve the quality of childcare services. Programs for the promotion of professionalism and job performance of childcare teachers should be developed and regular education, training and workshops should be provided to support application to childcare sites. This study is meant to improve the level of professionalism of daycare centers to achieve desirable professionalism and efficient organizational goals of daycare centers, and to improve the job performance of daycare centers and provide basic data to help them satisfy their jobs.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.2
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• pp.173-183
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• 2021

Objectives: This study evaluated the skin permeability of lawsone in henna hair dyes to understand the exposure characteristics of henna hair dyes in the human body. It examined the protective effects of protectants by applying protectants A, B, and C to test skin. Methods: Skin absorption tests were conducted using Franz diffusion cells according to OECD test guideline 428. After applying one kind of natural henna hair dye and chemical henna hair dye, respectively, to a standardized pig skin model, samples of receptor fluid were collected at 1h, 3h, 6h, and 24h. The skin permeation of lawsone was determined using HPLC. After the skin absorption experiment, the skin to which hair dye was applied was analyzed to determine the residual amount of lawsone in the skin. Results: The cumulative permeation of both natural and chemical henna hair dyes increased over time, and the natural henna hair dye had a flux value (t=3.194, p<.05) high both in the K_p value (t=3.207, p<.05) and the residual amount (t=22.701, p<.001). For skin treated with a protectant, the cumulative permeation of natural henna hair dye 24h control and the cumulative permeation of protectant A, B, and C increased over time. Flux and K_p values were in the order control > protectant A > protectant C > protectant B. The residual amount (F=4.469, p<.05) was in the order of protectant C > protectant A > protectant B > control. At 3h, the dye application time of natural henna hair dye, the lawsone flux value (F=4.454, p<.05) and K_p value (F=4.455, p<.05) were higher in the control group than in the protectant groups. The 24h cumulative permeation of the chemical henna hair dye increased with time in both the control and the protectant groups, and the flux and K_p values were in the order of protectant A > protectant C > protectant B > control. The residual amount (F=7.901, p<.01) was in the order of protectant B > protectant A> protectant C > control. Conclusions: Within the normal dyeing time for henna hair dye (three hours for natural henna hair dyes and 30 minutes for chemical henna hair dyes) lawsone skin penetration was not observed even when no protective agent was applied. After that time, however, evidence of skin penetration and retention of lawsone and the protective effect of protective agents were observed.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.1
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• pp.19-26
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• 2021

The purpose of this study is to provide an environment that can support the development of the virtual asset industry. The limiting factors and countermeasures currently possessed by the virtual asset industry were considered in terms of legal and institutional aspects, technical aspects, and market aspects.Small businesses classified as virtual asset operators have difficulty meeting the government's requirements.Accordingly, SMEs with insufficient funds and manpower are withdrawn from the market, creating an environment where only large-scale enterprises with capital power survive.It is difficult to develop desirable technologies and markets in the virtual asset technology industry. In addition, small and medium-sized companies may be expelled from the market, causing damage to current users. Therefore, in terms of legal and institutional aspects, there is a lack of an exact scope of virtual asset providers, and thus it is necessary to respond to the controversial elements of virtual asset providers. In terms of technology, it is necessary to cope with the slowdown of the P2P method, the difficulty in recovering errors, and the absence of operational experts. Therefore, technology standardization and stabilization are required, and efforts must be made to cultivate operational technical personnel who can support them.In terms of the market, it is necessary to prepare measures to protect users of virtual assets and to establish countermeasures for companies operating virtual assets against weak user protection, inadequate application of the AML method, and limitations of taxation. This study is expected to contribute to active utilization support or related policies in the virtual asset industry.

• Applied Chemistry for Engineering
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• v.22 no.6
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• pp.617-622
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• 2011

Ozone-based advanced oxidation was applied for the treatment of anaerobic digestion effluent of livestock wastewater. Initial COD and color value were 930 mg/L and 0.04, respectively, and the 1/10-diluted wastewater was used for the study. The treatment characteristics were compared between the conventionally generated ozone ($105{\mu}m$) and microbubbled ozone ($13{\mu}m$). The use of microbubbled ozone improved the removal of chemical oxygen demand (COD) and color by 85% and 26%, respectively, compared with the conventionally bubbled ozone. The application of microbubbled $O_3/UV$, $O_3/H_2O_2$, $O_3/UV/H_2O_2$ combinations resulted in 5~10% higher color removal than ozone alone, which implies that the contribution of UV or $H_2O_2$ is not significant in color removal. On the other hand, COD removal could be increased two folds compared with ozone alone through $O_3/UV/H_2O_2$ combination. The contribution of $H_2O_2$ was bigger than UV for COD removal with microbubbled ozone. Due to the enhancement of dissolved ozone and radical activity, the microbubbling enabled us to additional COD removal even after stopping ozone supply in the presence of UV or $H_2O_2$.

• Food Engineering Progress
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• v.22 no.4
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• pp.381-385
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• 2018

Various rheological methods to measure the hardness of instant cooked rice by a texture analyzer were investigated and compared. Specifically, instant white rice samples with a wide range of hardness were subjected to four different rheological tests with disk, cylinder, rod, and cone probe whose results were inter-correlated. All the measurements demonstrated that the hardness of instant rice was reduced with increasing moisture content and showed negatively linear relationships. Out of the four tests applied in this study, the highest coefficient of correlation ($R^2=0.9268$) was observed distinctly in the cone probe test, where both compressive and shear forces can be applied to deform individual rice grains. However, the cylinder probe test had the lowest coefficient of correlation ($R^2=0.7247$) because it may be ineffective in causing direct deformation of individual rice grains. Furthermore, when the hardness values (N) were converted to stress (Pa), highly linear correlations ($R^2{\approx}0.99$) were observed between the tests with similar probe geometry and force application.

• The Korean Journal of Food And Nutrition
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• v.33 no.6
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• pp.692-701
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• 2020

Centella asiatica (CA) has been widely used as herbal plants. It is a valuable resources. The aim of the present study was to evaluate physiological activities of solvent extracts from CA cultivated in Chungju, Korea (Good tiger care). After preparing water (cold-water, CA-WE; hot-water, CA-HWE) and EtOH extracts (50% EtOH, CA-50E; 70% EtOH, CA-70E), their total polyphenol, flavonoid, and triterpenoid contents, and anti-oxidant activities, and anti-inflammatory activities were examined and compared. CA-70E showed the most potent anti-oxidant activity based on ABTS radical scavenging activity and reducing ability assays, while CA-50E and CA-70E showed the highest DPPH radical scavenging activity. Among major triterpenoid glycosides present in CA, madecassoside and asiaticoside contents were found to be the highest in CA-70E, and madecassic acid and asiatic acid were the highest in CA-50E. In LPS-stimulated RAW 264.7 cells, CA-70E showed the highest TNF-α inhibitory activity, although CA-50E and CA-70E similarly inhibited nitric oxide production. Ethanol extracts significantly inhibited IL-6 and IL-8 production more than water extracts using TNF-α/IFN-γ-stimulated HaCaT cells, indicating its better inhibitory against skin inflammation. Therefore, Chungju-CA EtOH extract, especially 70% EtOH extract, has high physiologically active ingredients and potent anti-oxidant and anti-inflammatory activities, suggesting its industrial application as a functional material.

• Applied Chemistry for Engineering
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• v.32 no.3
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• pp.290-298
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• 2021

A purification process was performed for the application of natural graphite as an anode material. The influence of the structural change and impurity content of graphite according to the process on the anode electrochemical characteristics was investigated. Natural graphite was chemically/physically purified by acid-treatment which used different amounts of solution of ammonium fluoride/sulfuric acid in the same ratio and thermal treatment used different temperatures (800~2500 ℃). Acid-treatment had limitation to remove impurities, and identified that all impurity contents was removed except some traces of atom such as Si by after progressed thermal-treatment until 2500 ℃. The anode materials characteristic of graphite treated by purification process was improved, and changes in the structure and impurity contents affected dominantly the capacity, rate property and initial Coulombic efficiency. Consequently, the complex purification process improved the graphite structure and also the performance of lithium ion battery by controlling the excessive formation of solid electrolyte interphase and expanding Li⁺ insertion space originated from the effective removal of impurities.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.3
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• pp.123-128
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• 2021

For accurate speed and current control in industrial applications, SRM (Switched Reluctance Motor) is very important to synchronize the stator phase excitation and rotor position in the drive due to its nature. In general, position sensors such as encoder and resolver are used to generate rotational force by exciting the stator winding according to the rotor position and to control the motor by using speed and position information. However, for these sensors, 1) the cost of the sensors is quite large in terms of price, so the proportion of the motor system to the total system cost is high. 2) In terms of mechanical, position sensors such as encoders and resolvers are attached to the stator to increase the size and weight. In conclusion, in order to drive the SRM, control based on the rotor position information should be basically performed, and it is important to design the SRM driving system according to the environment in consideration of the application field. Therefore, in this paper, we intend to study the driving and control characteristics of SRM through variable switching duty control by designing a low-cost analog driving device, deviating from the general control system using the conventional encoder and resolver.

• Journal of the Korean Society of Radiology
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• v.15 no.3
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• pp.371-379
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• 2021

The personality education of the existing university is mainly focused on occupational ethics education or basic education, but the purpose and method of the personality education program is changed in preparation for the 4th industry and the related occupational personality education program is needed. In Korea, however, there is a lack of research on the development of educational programs for occupational personalities that Health care workers should have. Therefore, this study aims to confirm the effect by developing and applying a program for occupational personality education for Health care workers required for the 4th Industrial Revolution based on case-based learning. In this study, general cases and occupational cases were developed, and research tools were developed to verify the effectiveness of the occupational personality education program. The program developed in this study was provided four times for 52 students in the second and third grades college and university. This study was performed with a single group pre-post design. The data were analyzed by means of mean, standard deviation, and paired t-test. By applying the program developed in this study, accountability, honesty, consideration, collaboration, communication, and competency were improved. This confirmed the positive effect of vocational character education

• Applied Chemistry for Engineering
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• v.32 no.1
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• pp.28-34
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• 2021

SiO2/Ag core-shell nanoparticles were synthesized by combining modified Stöber process and reverse micelle method using acetoxime as a reducing agent in water/dodecylbenzenesulfonic acid (DDBA)/cyclohexane reverse micells. The SiO2/Ag core-shells were studied for structure, morphology and size using UV-visible spectroscopy, XRD, SEM and TEM. The size of a SiO2/Ag core-shell could be controlled by changing the [water]/[DDBA] molar ratio (WR) values. The size and the polydispersity of SiO2/Ag core-shells increased with increase of the WR value. The resultant Ag nanoparticles exhibit a strong surface plasmon resonance (SPR) peak at 430 nm over the amorphous SiO2 nanoparticles. The SPR peak shifted to the red side with increase in nanoparticle size. Conductive pastes with 70 wt% SiO2/Ag core-shell were prepared, and the pastes were coated on the PET films using a screen-printing method. The printed paste film of the SiO2/Ag core-shell showed higher surface resistance than the commercial Ag paste in the range of 460~750 µΩ/sq.