• Korean Journal of Environmental Biology
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• v.38 no.4
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• pp.667-677
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• 2020

This study was conducted to investigate the fish fauna and characteristics of the Carassius auratus population in the Boryeong Reservoir in Chungcheongnam-do from October 2017 to June 2018. The collected fish were identified as 3,506 individuals of 15 species from a total of nine families. The dominant and subdominant species were H. nipponensis with 1,706 (48.6%) individuals and C. auratus with 1,021 (29.1%) individuals, respectively. The biomass of C. auratus (246,130g), P. fulvidraco(50,610g), C. cuvieri (14,730 g), S. asotus (11,560 g), and C. carpio (10,930 g) was analyzed. The results of the community analysis showed a dominant index value of 0.87 (±0.2), a diversity index value of 0.78 (±0.5), an evenness index value of 0.47 (±0.2), and a richness index value of 0.99 (±0.5). The length-weight analysis of C. auratus showed a regression coefficient b of 3.06, and a condition factor (K) of 0.0004 with a positive slope. The frequency distribution of the total length analysis of the C. auratus population inhabiting the Boryeong Reservoir showed a high distribution of lengths between 140-160 mm and a low distribution between 230-280 mm. The normalized difference water index (NDWI) was analyzed over the Boryeong Reservoir water surface from 2013 to 2014 using Landsat 8 channel data. The areas where the NDWI was decreased were located at the inflow site of Ungcheon Stream.

• Journal of Sensor Science and Technology
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• v.30 no.3
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• pp.154-164
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• 2021

In this study, the IoT sensor technology required for improving the survival rate and high-density productivity of individual shrimp in smart shrimp farming (which involves the usage of recirculating aquaculture systems and biofloc technology) was analyzed. The principles and performances of domestic and overseas water quality monitoring IoT sensors were compared. Furthermore, the drawbacks of existing aquaculture monitoring technologies and the countermeasures for future aquaculture monitoring technologies were examined. In particular, for farming white-legged shrimp, an IoT sensor was employed to collect measurement indicators for managing the water quality environment in real-time, and the IoT sensor-based real-time monitoring technology was then analyzed for implementing the optimal farming environment. The results obtained from this study can potentially contribute to the realization of an autonomous farming platform that can improve the survival rate and productivity of shrimp, achieve feed reduction, improve the water quality environment, and save energy.

• Korean Journal of Mineralogy and Petrology
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• v.33 no.4
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• pp.391-405
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• 2020

Leaching chracteristics of Andong-dam sediment was conducted for heavy metal and nutrients. Five mixed sediment samples were prepared and leaching was conducted under aerobic and anaerobic condition for 60 days. Cd, Cu, Pb, Cr, Zn, Hg, As, Fe, Mn, phosphorus, and nitrogen were analyzed at each sampling time. The leaching rate of phosphorus was higher in anaerobic condition comparing with that of under aerobic condition. Some samples showed higher than the water-quality level IV. In case of As and Cd which showed highest contamination level in the sediment, leached concentration were 0.028 mg/L and 0.003 mg/L in maximum, respectively. The leached concentration is below than the lake water quality standard of Korea. Other heavy metals including Cu, Pb, and Cr also showed similar trend. Five step sequential extraction showed that easily extractable 1-2 step portion such as ion-exchangeable and adsorbed one was less than 10% and the most of the portion was residual. For As and Cd, the residual portion were 80% and 95% respectively indicating the risk by the heavy metal leaching into the lake for a short period was not high in comparing with the contamination levels.

• Journal of Mushroom
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• v.18 no.4
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• pp.311-316
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• 2020

The effect of the nitrogen content of sawdust medium (1.2~1.8%) and the restriction stage temperature (2, 4, and 6℃) on the growth and storage characteristics of Flammulina velutipes (winter mushroom) were investigated. With increased nitrogen content, the growth days shortened and the yield of the fruiting body increased. The effect of restriction temperature on the growth of the fruiting body differed depending on the nitrogen content. No difference in restriction temperature was evident for T1 with a low nitrogen content of 1.28%. In medium with a nitrogen content ≥1.55%, the yield and length of the pileus and stipe increased as the restriction temperature decreased. The weight loss ratio according to the storage period did not change according to the nitrogen content in the medium. A low weight loss ratio of 1.50 to 1.93% was observed at a restriction temperature <4℃. When T3 with high nitrogen content in the medium was treated at a restriction temperature of 4℃, the fruiting body color values after 31 days of storage were 84.81 (L) and 6.3 (ΔE). This color change was minute compared to that after other treatments. The sensory characteristics score was 5.2 after 31 days of storage, and the quality remained acceptable for consumption.

• Korean Journal of Food Science and Technology
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• v.54 no.3
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• pp.351-361
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• 2022

This study aimed to investigate the differences in the isomaltooligosaccharides present during Makgeolli production according to the type of Nuruk used, fermentation period, and presence of microorganisms. Makgeolli was fermented for 15 days using three kinds of Nuruk (Soyul, Sansung, and Jinju) with and without microbial growth inhibitors. Isomaltooligosaccharide contents were analyzed using high performance anion exchange chromatography. The most abundant isomaltooligosaccharide was panose, which was highest in Makgeolli produced using Soyul Nuruk (SH) on day 6 (24.7 mM), followed by Makgeolli prepared using Sansung Nuruk (SS) on day 2 (18.2 mM) and Makgeolli prepared using Jinju Nuruk (JJ) on day 3 (10.8 mM). Isomaltotriose and isomaltotetraose, which were generated in the control, were not detected when microbial growth was suppressed. Based on these results, isomaltooligosaccharide production is affected more by the enzymes produced by microorganisms during Makgeolli fermentation than by Nuruk itself.

• The Korean Journal of Food And Nutrition
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• v.34 no.6
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• pp.612-620
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• 2021

To increase the utilization of Centella asiatica (CA), enzymes such as cellulase and pectinase were added and the physicochemical properties of the treated CA were analyzed. In addition, apple-CA jam was prepared using the enzyme-treated CA, which had the best antioxidant properties, and the physicochemical and sensory qualities of the jam were measured. There was a high content of ascorbic acid, polyphenols, flavonoids, reducing sugar, amino acid, minerals and DPPH radical scavenging activity in the enzyme-treated group. The antioxidant component and activity in the jam prepared by adding enzyme-treated CA increased with an increase in the amount of enzyme-treated CA. In the soluble solids, the higher the amount of enzyme-treated CA, the higher the value, but there was no significant difference in pH. The sensory evaluation of the jam, in particular the taste, showed that the highest preference was observed when the enzyme-treated CA was added in the range of 5.0~6.7%, and the control group showed the lowest preference. There was no significant difference in flavor and spreadability among the treatment groups, however, the control group showed the highest color preference. In the overall acceptability, when 5.0% of enzyme-treated CA was added, the highest acceptability was shown.

• Korean Journal of Food Science and Technology
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• v.54 no.2
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• pp.209-217
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• 2022

In this study, Enterococcus faecalis BMSE-HMP005 isolated from human breast milk demonstrated antimicrobial effects against multidrug-resistant (MDR) bacterial strains. The bacteriocin produced by E. faecalis BMSE-HMP005 was fractionated using reverse-phase high-performance liquid chromatography. This fraction showed antimicrobial effects against both gram-positive and gram-negative MDR bacteria. No hemolytic reactions were observed. E. faecalis BMSEHMP005 was resistant to vancomycin; however, kanamycin, ampicillin, and erythromycin showed minimum inhibitory concentrations that were lower than the acceptable range provided by the European Food Safety Authority. For artificial gastric juice and bile acid, the survival rates were 98.67% and 95.70%, respectively. These results show the potential utility of E. faecalis BMSE-HMP005 as a probiotic with remarkable antimicrobial effects against MDR bacteria.

• Journal of People, Plants, and Environment
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• v.23 no.6
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• pp.655-665
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• 2020

Background and objective: This study was conducted to compare the cultivation environment, growth of cut flowers, and management performance of conventional farms and smart farms growing the standard cut chrysanthemum, 'Jinba'. Methods: Conventional and smart farms were selected, and facility information, cultivation environment, cut flower growth, and management performance were investigated. Results: The conventional and smart farms were located in Muan, Jeollanam-do, and conventional farming involved cultivating with soil culture in a plastic greenhouse, while the smart farm was cultivating with hydroponics in a plastic greenhouse. The conventional farm did not have sensors for environmental measurement such as light intensity and temperature and pH and EC sensors for fertigation, and all systems, including roof window, side window, thermal screen, and shading curtain, were operated manually. On the other hand, the smart farm was equipped with sensors for measuring the environment and nutrient solution, and was automatically controlled. The day and night mean temperatures, relative humidity, and solar radiation in the facilities of the conventional and the smart farm were managed similarly. But in the floral differentiation stage, the floral differentiation was delayed, as the night temperature of conventional farm was managed as low as 17.7℃ which was lower than smart farm. Accordingly, the harvest of cut flowers by the conventional farm was delayed to 35 days later than that of the smart farm. Also, soil moisture and EC of the conventional farm were unnecessarily kept higher than those of the smart farm in the early growth stage, and then were maintained relatively low during the period after floral differentiation, when a lot of water and nutrients were required. Therefore, growth of cut flower, cut flower length, number of leaves, flower diameter, and weight were poorer in the conventional farm than in the smart farm. In terms of management performance, yield and sales price were 10% and 38% higher for the smart farm than for the conventional farm, respectively. Also, the net income was 2,298 thousand won more for the smart farm than for the conventional farm. Conclusion: It was suggested that the improved growth of cut flowers and high management performance of the smart farm were due to precise environment management for growth by the automatic control and sensor.

• Korean Journal of Community Nutrition
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• v.26 no.6
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• pp.495-507
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• 2021

Objectives: This study examined regional differences in the intake of dietary total fat and saturated fatty acid (SFA) and their food sources among Korean adults. We also investigated the associations of SFA intake with metabolic diseases by region. Methods: This study included 13,926 adults (≥ 19y) who participated in the 2016 ~ 2019 Korea National Health and Nutrition Examination Surveys. The regions were divided into urban and rural areas according to the administrative districts where the participants lived. Using dietary data obtained from a 24-h recall, intake of total fat and SFA and their food sources were assessed by region. Metabolic diseases included obesity, abdominal obesity, and elevated total cholesterol and their association with SFA intake by region were examined using multiple logistic regression. Results: Of the participants, 19.6% lived in rural areas. In urban areas, the total fat and SFA intakes were higher than in rural areas: 21.2% of energy (%E) came from total fat and 6.9%E from SFA in urban areas, whereas 18.0%E came from total fat and 5.8%E from SFA in rural areas. The percentage of participants who exceeded the dietary reference intakes for total fat and SFA in urban areas was 16.5% and 41.9%, respectively, but 43.4% of participants in rural areas showed lower intake levels for total fat compared to the reference level. Young adults did not show regional differences in fat intake, and the percentage of subjects who exceeded the reference for SFA was high both in urban (58.5%) and rural (55.7%) areas. Among middle-aged and older adults, intake of fatty acids except for n-3 fatty acid was significantly higher in urban areas than in rural areas. About 69% of older adults in rural areas showed a lower intake of total fat compared to the reference level. The food sources for total fat and SFA were meat, soybean oil, eggs, and milk in both areas. The intake of fat from eggs, milk, mayonnaise, and bread was higher in urban areas, but the intake of fat from white rice and coffee mix was higher in rural areas. The SFA intake was positively associated with elevated serum total cholesterol in urban areas (4th quartile vs. 1st quartile, OR: 1.22, 95% CI: 1.06-1.40, P for trend: 0.043), but not in rural areas. Conclusions: Regional differences in total fat and SFA intakes and their food sources were observed among Korean adults. Our findings may help plan nutritional strategies to ameliorate regional health disparities.

• Journal of the Korean Wood Science and Technology
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• v.30 no.4
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• pp.87-95
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• 2002

Three different species of green and air-dried Korean bamboos were carbonized by using three different types of kilns designated as special (800~1000℃), improved (600~700℃) and simple kiln (400~500℃), and the bamboo vinegars obtained from the carbonization processes were characterized. In the case of the special kiln, most of the bamboo vinegars obtained at the first recovery stage showed high values of specific gravity and also in content of organic acid and water-soluble tar. The bamboo vinegars obtained from the improved kiln showed various physical properties depending on their species. In the case of simple kiln, the bamboo vinegars obtained from air-dried bamboos and at temperatures below 80℃, showed a higher specific gravity and more water-soluble tar as well as total organic components than those obtained at 80~150℃. A good linear relationship (correlation coefficient of ca. 0.90) was obtained between the specific gravities and the sum of organic acids and water-soluble tars. Therefore, this correlation coefficient might be a good index to determine the quality of bamboo vinegars. The major chemical constituents of the bamboo vinegars were acetic acid and considerable amounts of phenols: guaiacol, ethyl guaiacol, syringol, and methyl syringol.