• Corrosion Science and Technology
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• v.11 no.4
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• pp.120-128
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• 2012

The fatigue crack growth behaviors of SA508 Gr.3 Cl.2 low alloy steel in high temperature water environment were investigated. Overall, weld metal showed similar crack growth rate as that of base metal. At 0.01 Hz, fatigue crack growth rate (FCGR) was higher than that in air while the difference was smaller at 0.1 Hz. Also, FCGR showed ${\Delta}K$ dependency at 0.1 Hz only, indicating that the environmental effect was much greater at slower loading frequency of 0.01 Hz. FCGR of SA508 Gr.3 Cl.2 low alloy steel was compatible to or smaller than the ASME Sec. XI fatigue reference curves in high temperature water environment.

• Journal of Microbiology and Biotechnology
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• v.29 no.4
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• pp.617-624
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• 2019

Bacterial nanocellulose (BNC) which is generally synthesized by several species of bacteria has a wide variety of industrial uses, particularly in the food and material industries. However, the low levels of BNC production during the fermentation process should be overcome to reduce its production cost. Therefore, in this study, we screened and identified a new cellulose-producing bacterium, optimized production of the cellulose, and investigated the morphological properties of the cellulosic materials. Out of 147 bacterial isolates from ripened fruits and traditional vinegars, strain SFCB22-18 showed the highest capacity for BNC production and was identified as Komagataeibacter sp. based on 16S rRNA sequence analysis. During 6-week fermentation of the strain using an optimized medium containing 3.0% glucose, 2.5% yeast extract, 0.24% acetic acid, 0.27% $Na_2HPO_4$, and 0.5% ethanol at $30^{\circ}C$, about 5 g/l of cellulosic material was produced. Both imaging and IR analysis proved that the produced cellulose would be nanoscale bacterial cellulose.

• Journal of Digital Convergence
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• v.20 no.4
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• pp.133-145
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• 2022

As a result of the study, the poorest keywords were information, big data, management, policy, government, law, and smart. In addition, as a result of network analysis, related research was being conducted on topics such as data industry policy, data governance performance, defense, governance, and data public. The four topics derived through topic modeling were "DG policy," "DG platform," "DG in laws," and "DG implementation," of which research related to "DG platform" showed an increasing trend, and "DG implementation" tended to shrink. This study comprehensively summarized data governance-related studies. Data governance needs to expand research areas from various perspectives and related fields such as data management and data integration policies at the organizational level, and related technologies. In the future, we can expand the analysis targets for overseas data governance and expect follow-up studies on research directions and policy directions in industries that require data-based future industries such as Industry 4.0, artificial intelligence, and Metaverse.

• International Commerce and Information Review
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• v.13 no.1
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• pp.29-52
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• 2011

A predictable and manageable output is desirable for most businesses. However, it is very difficult to control the quality and quantity of products in the food and agriculture business. Predictable outputs help managers plan their marketing, sales, and inbound and outbound logistics, but these are not easy to achieve in the food and agriculture business. Various industries have adopted different levels of automation and utilization of information systems for quality/quantity control; however e-Commerce of the food and agriculture industry is far behind those of other industries. Today, the food and agriculture industry is supposed to be more integrated than ever in order to reduce risks and improve processing costs, from farm to table. Since its operations including production, processing, storage, distribution, and management are dispersed all over the world, the food and agricultural industries now depend more on IT than other industries. This study attempts to develop a framework to analyze the current situation of agricultural product e-Commerce in Korea, and finds out the actual situation of the farmers operating on-line shopping systems through the developed framework and suggests some improvements.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.5 no.2
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• pp.172-183
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• 1995

The airborne concentrations of the welding fumes produced during $CO_2$ arcwelding process at shipbuilding, shiprepairing, container manufacturing and car accessary manufacturing industry were investigated. The effects how much reduced the welding fume were checked when the portable fan was used. The results were as follows; 1.The geometric mean of welding fume concentration in shipbuilding factory was $10.05mg/m^3$. This exposure concentration was higher than other 3 manufacturing industries at 95% confidence level. 2. The sampling filters for welding fume could be digested with acid within 1 hour by microwave oven. The recoveries for investigated metal elements were all over 95%. 3. The optimal wavelength could be selected for the simultaneous analysis of 8 metal elements by ICP(Inductively Coupled Plasma). 4. Noxious gases($O_1,NO_2$) produced during $CO_1$ gas arc welding process were detected that the concentration of ozone($O_1$) was less than 0.01 ppm and that of nitrogen dioxide($NO_2$) was 0.01-0.03 ppm. 5. The geometric mean of welding fume particle diameter was $1.26{\mu}m$ and geometric standard deviation was 1.51 for the counts when particle an analyzer(ELZONE) had been used. 6. When the portable fan had been used,the reduced percent of total welding fume for workers was about 47.8% when portable fan was applied to blow and 71.7% when to exhaust.

• Corrosion Science and Technology
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• v.6 no.3
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• pp.128-132
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• 2007

For a quantitative inspection on the performance of weathering steel bridges, we have investigated the relationship between the corrosion rate and the composition of the rust layers formed on weathering steel bridges located in various environments in Japan and applied a protective ability index (PAI) to the bridges. The corrosion rates were clearly classified by the PAI, ${\alpha}/{\gamma}*$ and sub index of $({\beta}+s)/{\gamma}*$, where $\alpha$, \gamma*, $\beta$ and s are the mass ratio of crystalline $\alpha-FeOOH$, the total of $\gamma$-FeOOH+ $\beta$-FeOOH + the spinel-type iron oxide (mainly $Fe_3O_4$), $\beta-FeOOH$ and spinel-type iron oxide, analyzed by powder X-ray diffraction, respectively. In the case of ${\alpha}/{\gamma}$*>1, the rust layer works protective enough to reduce the corrosion rate less than 0.01 mm/y. The sub index $({\beta}+s)/{\gamma}*$<0.5 or >0.5 classifies the corrosion rate of the non-protective rust layers, therefore the former state of the rust layer terms inactive and the latter terms active. The quantitative inspection of a weathering steel bridge requires a performance-inspection (PI) and periodical deteriorationinspections (DI). The PI can be completed by checking of the PAI, ${\alpha}/{\gamma}*$. The DI on the weathering steel bridges where deicing salt is sprinkled can be performed by checking the PAI, $({\beta}+s)/{\gamma}*$.

• The Korean Journal of Franchise Management
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• v.14 no.4
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• pp.67-83
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• 2023

Purpose: The beauty market is growing rapidly and becoming more competitive as new shops enter the market and offer similar products and services. The way for industries such as beauty shops to succeed in market competition is to understand customer needs and provide a marketing mix appropriate for those needs. Research design, data, and methodology: The survey was conducted for a total of 4 days from October 4 to October 7, 2023, and a total of 2,431 copies were distributed and 463 copies were returned. Excluding 2 copies with insincere responses, 461 copies were used for analysis. The data were analyzed with SPSS 25.0 and SamrtPLS 4.0. Result: Product, price, promotion, people, and physical evidence influence perceived value, but place and process didn't. Product, process, and physical evidence influence reputation, but price, location, promotion, and people didn't. Perceived value influences revisit intention but did not reputation. Reputation influences revisit intention. Conclusions: First, beauty shops must develop beauty services that can satisfy customers' needs. Second, beauty shops must continue to invest in external facilities and interior design. Third, intangible service processes can help the beauty shop's reputation. Fourth, beauty shops need to maintain a balance between price and perceived value so that customers can be satisfied with the service experience.

• Journal of Environmental Health Sciences
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• v.29 no.4
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• pp.21-26
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• 2003

We examine the metabolites(DCB and acetyl DCB) extracted from exfoliated urothelial cells of 33 workers who employed DCB-handling industries. The characteristics of workers submitted urine, whose age, working years and smoking persons were 41.9$\pm$11.1, 8.7$\pm$5.5 and 25(32.0%), respectively. DNA adduct was isolated from the exfoliated urothelial cells by applying $^{32}$ p-postlabeling procedure. Metabolites(DCB and acetyl DCB) were extracted from DNA adducts by hydrolyzing and N-glycosylase. Concentrations of DCB and acetyl DCB were 28.6$\pm$5.25 ng/g DNA, and 17.0$\pm$3.73 ng/g DNA, respectively. The regression between DCB level and exposure years of workers is y = 1.668 + 2.588x(p = 0.005, $r^2$= 0.394). The regression between acetyl DCB level and exposure years of workers is y = 8.071 + 1.325x(p = 0.076, $r^2$= 0.222). Smoking workers are significantly higher than non-smoking workers on DCB and acetyl DCB level(p = 0.065 and 0.021, respectively). DCB level was 33.9$\pm$7.14 ng/g DNA on smokers, and 23.1$\pm$9.97 ng/g DNA on non-smokers. Acetyl DCB was 25.1$\pm$5.27 ng/g DNA on smokers, and 8.92$\pm$7.22 ng/g DNA on non-smokers.

• The Korean Journal of Malacology
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• v.7 no.1
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• pp.87-93
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• 1991

Heavy metals, Cd, Pb, Cu, Mn, Zn in water, sediments and molluscs along coast line of Hwang-hae(Yellow sea)were examined. The collection sited werer close to esturies of Kum-gang and Mankyeong-Gang, where industries have been rapidly developed along the rivers in recent in recent years. Cadmium and lead in water were 0.32ppb and 4.12 ppb respectively on Kun-san, but not on Jang hang. In general, Cd, Pb, Mn and Zn were detected in the regions of mouth paart of rivers, whereas none or far less amounts were detected from Puan, a control site: 20km apart from estury of Mangyeong Gang. Cd and Pb in sediments of Kunsan were 0.46ppm and 9.31ppm respectively and 0.36ppm and 0.41ppm in Shim-po, but far less amounts in Byeon san.Heavy metals in shellfish were: Cd 0.78ppm and Pb 0.42ppm in Kun san, 0.74ppm and 0.74ppm in Shim po, and showed higher values compare to other sites. In general, heavy metal contamination of sedimets and molluscs in each are were correlated with grade of the water pollution due to heavy metals.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2319-2323
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• 2007

Introduction of a difluoromethylene group into organic compounds has been observed to impart them with positive properties, as viewed by a wide range of industries. Here, synthesis of 3,3-difluoro-2-pyrrolidone derivatives (7) was accomplished by the reaction of ethyl 2,2-difluoro-4-iodo-4-(trimethylsilyl) butanolate (4) with primary amines followed by desilylation. The key intermediate (4) was prepared from the addition reaction of trimethylvinylsilane (3) to ethyl difluoroiodoacetate (2) in the presence of Cu(0). Ethyl difluoroiodoacetate (2) was prepared starting from ethyl bromodifluoroacetate (1) via Reformatsky-type reaction.