• Food Science and Preservation
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• v.14 no.6
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• pp.617-623
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• 2007

To utilize the non-heat treated alcoholic by-products of brown rice(Goami) as food sources, the quality characteristics change according to the treatment conditions of ${\alpha}-amylase$ were evaluated. It resulted that the increase of hydrolysis temperature correspondingly increased the soluble solids, total dietary fiber and total sugar in the by-products of Goami, and the highest reducing sugar content was observed at $80^{\circ}C$. The free amino acids contents were tended to slowly decrease by the hydrolysis temperature more than $70^{\circ}C$, and the highest content of oligosaccharides were detected at the hydrolysis temperature of $80^{\circ}C$. The soluble solid according to the ${\alpha}-amylase$ concentration resulted to increase with the increase of the enzyme concentration and the total dietary fiber revealed similarly showing approximately 0.65%. The high content of reducing sugars was observed at the enzyme concentration around 0.08%(v/w). Total sugars and oligosaccharides contents tend to increase as the concentration of enzyme increased, and the content of oligosaccharides acquired at the enzyme concentration more than 0.10%(v/w) maintained to show rather similar contents. The soluble solids and total dietary fiber by hydrolysis time were found to show 6.66% and 0.65%, respectively at more than 60 min of hydrolysis, and the reducing sugars and total sugars were found to be 3,600 and 4,800 mg% in all treatment groups showing no significant difference. The content of oligosaccharides was increased with the increase of hydrolysis time, and the content was similar at more than 90 min of hydrolysis by ranging around 2,100 mg%. Based upon these results, the by-products of Goami are expected to be used as various food sources showing the highest dietary fiber and oligosaccharides contents by the hydrolysis at $80^{\circ}C$ for 90 min with the addition of 0.10%(v/w) of ${\alpha}-amylase$.

• Food Science and Preservation
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• v.20 no.4
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• pp.546-553
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• 2013

In this study, we examined the antioxidant activity of the Sumaeyaksuk (Artemisia argyi) tea extracts from different pre-treatment and extraction methods. Sumaeyaksuk was sun-dried for 3.5 days (control, RC) and aged at a temperature of $60^{\circ}C$ for 3.5 days (HA), 7 days (HB), and 14 days (HC), respectively. Each sample was extracted in $60^{\circ}C$ and $95^{\circ}C$ hot water for 2 minutes. The soluble solids content of HA from the $60^{\circ}C$and $95^{\circ}C$ hot water extraction were $0.52{\pm}0.18%$ and $0.92{\pm}0.18%$, respectively. The soluble solids content was increased by the higher extraction temperature. The reducing sugar content of RC was $9.55{\pm}0.18mg/g$ in the $95^{\circ}C$ extraction, which was significantly higher than in the $60^{\circ}C$ extracted sample. However, the reducing sugar content did not show a remarkable difference based on aging periods. The total phenolic compound content of the $95^{\circ}C$ extracted samples was $3.36{\pm}0.13{\sim}9.88{\pm}0.23mg/g$, which was significantly higher than that of the $60^{\circ}C$ extracted sample. The ABTS radical scavenging activity of the $60^{\circ}C$ extracted RA and HA samples were 35.63% and 95.10%, respectively. Moreover, the radical scavenging activity increased to 63.35% and 96.78%, respectively, in the $95^{\circ}C$ extracted samples. As a result of the high temperature, the extracted sample showed an increase in the FRAP. In the RC sample, the FRAP was two times higher in the $95^{\circ}C$ extracted sample ($181.28{\pm}2.90{\mu}M$) than in the $60^{\circ}C$ extracted sample ($83.88{\pm}0.43{\mu}M$).

• Korean Journal of Environment and Ecology
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• v.33 no.5
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• pp.605-619
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• 2019

The objective of this study was to analyze eutrophication characteristics, empirical model analysis, and variation of water quality according to monsoon intensity in Hapcheon Reservoir for 16 years from 2002 to 2017. Long-term annual water quality analysis showed that Hapcheon Reservoir was in a meso-nutrition to eutrophic condition, and the eutrophic state intensified after the summer monsoon. Annual rainfall volume (high vs. low rainfall) and the seasonal intensity in each year were the key factors that regulate the long-term water quality variation provided that there is no significant change of the point- and non-point source in the watershed. Dry years and wet years showed significant differences in the concentrations of TP, TN, BOD, and conductivity, indicating that precipitation had the most direct influence on nutrients and organic matter dynamics. Nutrient indicators (TP, TN), organic pollution indicators (BOD, COD), total suspended solids, and chlorophyll-a (Chl-a), which was an estimator of primary productivity, had significant positive relations (p<0.05) with precipitation. The Chl-a concentration, which is an indicator of green algae, was highly correlated with TP, TN, and BOD, which differed from other lakes that showed the lower Chl-a concentration when nutrients increased excessively. Empirical model analysis of log-transformed TN, TP, and Chl-a indicated that the Chl-a concentration was linearly regulated by phosphorus concentration, but not by nitrogen concentration. Spatial regression analysis of the riverine, transition, and lacustrine zones of $log_{10}TN$, $log_{10}TP$, and $log_{10}CHL$ showed that TN and Chl-a had significant relations (p<0.005) while TN and Chl-a had p > 0.05, indicating that phosphorus had a key role in the algal growth. Moreover, the higher correlation of both $log_{10}TP$ and $log_{10}TN$ to $log_{10}CHL$ in the riverine zone than the lacustrine zone indicated that there was little impact of inorganic suspended solids on the light limitation in the riverine zone.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.295-303
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• 2021

We analyzed berry skin coloration, anthocyanin accumulation, and plant hormone contents in berry skins to determine the effect of night temperature at veraison on berry skin coloration in 'Kyoho' grapevines (Vitis labruscana L.). Vines were grown under 21, 24, and 27℃ at night for 20 days at veraison, from 40 to 60 days after full bloom (DAFB). Berry skin coloration of 'Kyoho' grapes was more suppressed in 27℃ treated vines, followed by that in 24℃ treated vines, than that in 21℃ treated vines. Cluster and berry weight and soluble solids content was lower in 24 and 27℃ treated vines than in 21℃ treated vines. Anthocyanin started to accumulate from 60 DAFB in berry skin of 21℃ treated vines, and malvidin and total anthocyanin content increased until 100 DAFB. The total and most of the individual anthocyanins decreased in 24 and 27℃ treated vines; however, peonidin did not decrease in 24℃ treated vines compared to that in 21℃ treated vines. Abscisic acid (ABA) peaked at veraison in berry skins of 21℃ treated vines and decreased thereafter until 100 DAFB. The increase in ABA content was inhibited in berry skins of 24 and 27℃ treated vines. Gibberellin (GA) content in berry skins decreased rapidly at veraison, with the decrease being slower under 27℃ than under 21℃. ABA/GA in berry skins of 21℃ treated vines peaked at 60 DAFB and decreased thereafter until 100 DAFB. However, ABA/GA decreased in berry skins of 24 and 27℃ treated vines, with reduced anthocyanin accumulation. Therefore, high night temperature (above 24℃) at veraison suppressed the berry skin coloration of 'Kyoho' grapes with changes in anthocyanin contents and composition due to the decrease in ABA/GA ratio and fruit soluble solids contents.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.429-440
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• 2021

During the growing period, the integrated solar radiation inside the greenhouse was 12.7MJ·m^-2d^-1, and which was 90% of the average daily global radiation outside the greenhouse, 14.1MJ·m^-2d^-1. The 24-hour average temperature inside the greenhouse from July to August, which has the highest temperature of the year, was 3.04℃ lower than the outside temperature, and 4.07℃ lower after the rainy season. Before the operation of fog cooling system, the average daily RH (%) was lowered to a minimum of 40% (20% for daytime), making it inappropriate for paprika cultivation, but after the operation of fog system, the daily RH during the daytime increased to 70 to 85%. The average humidity deficit increased to a maximum of 12.7g/m³ before fog supply, but decreased to 3.7g/m³ between July and August after fog supply, and increased again after October. The daytime residual CO₂ concentration inside the greenhouse was 707 ppm on average during the whole growing period. The marketable yield of paprika harvested from July 27th to November 23rd, 2020 was higher in 'DSP-7054' and 'Allrounder' with 14,255kg/10a and 14,161kg/10a, respectively, followed by 'K-Gloria orange', 'Volante' and 'Nagono'. There were significant differences between paprika cultivars in fruit length, fruit diameter, soluble solids (°Brix), and flash thickness (mm) of paprika produced in summer season at large single-span plastic greenhouse. The soluble solids content was higher in the orange cultivars 'DSP-7054' and 'Naarangi' and the flesh thickness was higher in the yellow and orange cultivars, with 'K-Gloria orange' and 'Allrounder' being the thickest. The marketable yield of paprika, which was treated with cooling and heating treatments in the root zone, increased by 16.1% in the entire cultivars compared to the untreated ones, increased by 16.5% in 'Nagano', 10.3% in the 'Allrounder', 20.2% in the 'Naarangi', and 17.3% in 'Raon red'.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.1
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• pp.40-47
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• 2019

This study was conducted to investigate the effect of planting density on plant growth, yield, and quality in the sweet sorghum cultivar 'Chorong' (Sorghum bicolor (L.) Moench). Plants were cultivated at densities of 16.7, 11.1, 8.3, 6.7, and $5.6plants{\cdot}m^{-2}$. Factors related to yield and yield components were analyzed using correlation and multivariate analyses. There was no significant difference among plant densities in stem length from 20 to 110 days after sowing. But the stem diameter was thin, and a decrease in number of tillers occurred more rapidly as planting density increased. At harvest, juice and sugar yield were higher at densities of 16.7 (42.9, $4.16Mg{\cdot}ha^{-1}$, respectively) and 11.1 (37.1, $3.73Mg{\cdot}ha^{-1}$) $plants{\cdot}m^{-2}$ than at 8.3 (30.5, $2.96Mg{\cdot}ha^{-1}$), 6.7 (26.6, $2.41Mg{\cdot}ha^{-1}$), and 5.6 (24.7, $2.22Mg{\cdot}ha^{-1}$) $plants{\cdot}m^{-2}$. The soluble solids and total sugar contents were not different among treatments, but relatively high values were observed at the density of 11.1 and $8.3plants{\cdot}m^{-2}$. As plant density was increased from 5.6 to $11.1plants{\cdot}m^{-2}$, the lodging index (1 = no, 9 = lodging) increased rapidly from 2.00 to 6.33. To determine the optimal planting density, the number of typhoons and topographical characteristics should be considered. Correlation and principal components analyses revealed that plant density exhibited a positive relationship with fresh stem yield ($r=0.62^{**}$), dry stem yield ($r=0.58^{**}$), juice ($r=0.63^{**}$), and sugar yield ($r=0.66^{**}$), but a negative with stem diameter ($r=-0.65^{**}$). The yield factors were not statistically related to stem height, diameter, and number of nodes.

• Korean Journal of Remote Sensing
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• v.39 no.5_1
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• pp.655-667
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• 2023

Algal bloom outbreaks are frequently reported around the world, and serious water pollution problems arise every year in Korea. It is necessary to protect the aquatic ecosystem through continuous management and rapid response. Many studies using satellite images are being conducted to estimate the concentration of chlorophyll-a (Chl-a), an indicator of algal bloom occurrence. However, machine learning models have recently been used because it is difficult to accurately calculate Chl-a due to the spectral characteristics and atmospheric correction errors that change depending on the water system. It is necessary to consider the factors affecting algal bloom as well as the satellite spectral index. Therefore, this study constructed a dataset by considering water quality, hydrological and meteorological factors, and sentinel-2 images in combination. Representative ensemble models random forest and extreme gradient boosting (XGBoost) were used to predict the concentration of Chl-a in eight weirs located on the Nakdong river over the past five years. R-squared score (R²), root mean square errors (RMSE), and mean absolute errors (MAE) were used as model evaluation indicators, and it was confirmed that R² of XGBoost was 0.80, RMSE was 6.612, and MAE was 4.457. Shapley additive expansion analysis showed that water quality factors, suspended solids, biochemical oxygen demand, dissolved oxygen, and the band ratio using red edge bands were of high importance in both models. Various input data were confirmed to help improve model performance, and it seems that it can be applied to domestic and international algal bloom detection.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.2
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• pp.90-100
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• 2012

This study centering on 10 village - Bangjuks analyzed multifunctionality value of village Bangjuks which have been main water treatment system in Korean traditional villages. On the basis of understanding the structure and character of components such as the well, common spring, village waterway and others which making water-flow and consisting of aquatic system in Korean traditional village Bangjuk, the conclusion as the instrumental device of social and ecological role and ecological watershed management, securing the ecosystem soundness of the damaged or deteriated aquatic ecosystem due to the industrialization and urbanization is as below; 1. The traditional village Bangjuk was environmentally friendly hydraulic system which gathers waterways of village into a point including sewage water, retains and flows out to village through agricultural waterway. Through this Bangjuk, they have managed sewage and rainfall runoff flowed out village efficiently. It is not only a detention system of water but a kind of eco-friendly system that flow out water into the rivers after reusing and filtering it. 2. Around five traditional villages and five villages after modernization, this study classified the types of village Bangjuk as three types considering geographic location, size, etc; marsh type of low swamp, high water -low rice field type of natural flow stucture, low water - high rice field type requiring artificial irrigation facility. All the five traditional villages were turned out to be marsh type of low swamp. Geoji, Sanjeri, Ma-am, Yangchon of the agricultural villages were high water-low rice filed type, and Sangchoenri village was classified low water-high rice field type. 3. This study checked up the function of water purification of village Bangjuk. In Wonteo and Geji villages affected by discharge of village sewer and domestic sewage, the efficiency of ammonia nitrogen($NH_3-N$) and total phosphorus(T-P) was 56~95%, which was high. In Sangcheonri and Sanjeri villages strongly affected by stall and farmland, the efficiency of suspended solids(SS) was 70~85%, and that of total nitrogen(T-N) and total phosphorus(T-P) was 5.3~65%. 4. A water purification system can be found out in the system of village Bangjuk that filter out village sewage and rainfall runoff flowed through the settle and filter of pollution source and denitrification of plants. Through this system of village Bangjuk, it must be used as the basic facilities for the ecological watershed management. The sewage management system of village Bangjuk as a eco-filter must be used and studied as an eco-friendly facility for the ecological watershed management around the subwatershed and catchment.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.1
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• pp.35-46
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• 2009

In order to investigate spatial and temporal distributional characteristics of major water qualities in the Saemangeum area during the Saemangeum dike construction, salinity, COD, dissolved nutrients(DIN, Silicate) and heavy metals were analyzed from the surface water collected in April, May, August and November 2002. The overall value of Salinity, COD, DIN, and silicate in surface waters were in the range of $13.08{\sim}31.96\;psu$, $0.12{\sim}3.43\;mg/L$, $0.001{\sim}2.638\;mg/L$, and $0.010{\sim}3.181\;mg/L$, respectively. The COD and DIN in each survey showed the highest concentration at the mouth of Mangyeong river estuary(St. 1) where freshwater flow into the Saemangeum area. The concentrations of nutrients were high in the inner part of the Saemangeum dike with low-salinity, and low nutrients in the outer part of the dike with high-salinity, which strongly indicated that concentrations were adjusted by physical mixing. The ranges of dissolved metals and acid-soluble Hg in surface seawater were $0.006{\sim}0.115{\mu}g/L$ for Co, $0.26{\sim}0.114{\mu}g/L$ for Ni, $0.14{\sim}0.93{\mu}g/L$ for Cu, $0.04{\sim}0.53{\mu}g/L$ for Zn, $0.010{\sim}0.043{\mu}g/L$ for Cd, $0.010{\sim}0.795{\mu}g/L$ for Pb, and $0.25{\sim}4.16{\mu}g/L$ for Hg. The highest concentrations of some metals except for Cd were found at the estuary(Sts. 1 or 3). In most cases, a decreasing order of metal concentrations towards open sea(low-salinity$\rightarrow$high-salinity) was observed and showed positive relationship with DIN and silicate caused by land base pollutants input. On the other hand, due to Cd desorption from suspended solids in saline water, dissolved Cd concentrations were high in high-salinity area and low in low-salinity. In November, Co, Zn, Cu and Pb were relatively high in the northern area of the outer-side of Saemangeum, which was only influenced by the Geum river discharge. The concentrations of most dissolved metals of this study were lower than those of the past data in this area, but higher than those in Lena river estuary under the pristine environment.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.3
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• pp.308-318
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• 2013

Korean soybean varieties, 'Seonyu' and 'Hwangkeum' were planted in 2012, and three temperature gradient, Tc($19.8^{\circ}C$, ambient temperatured), $Tc+1.7^{\circ}C$, and $Tc+2.5^{\circ}C$, were artificially created by controlling the green house system during seed filling period. Mature seeds that developed under these conditions were analyzed for variances in physicochemical properties. The 100-seed weight and seed-coat ratio of soybean were decreased, but small seed rate was increased by high temperature during seed filling period. Protein content was increased, but oil content was decreased significantly with increasing the seed filling temperature. The decrement of carbon to nitrogen ratio (C/N), and the increment of monosaccharide, fructose and sucrose, in seeds explained that carbohydrate assimilation during seed filling was restricted by high temperature. Rapid increments of seed volume and weight were observed in the seeds of high seed filling temperature, but as soaking time increased the highest values were observed in the seeds of ambient seed filling temperature. The 100-seed weight and seed-coat ratio of soybean were closely related not only to the increment of soaking volume and weight, but also the increments of total dissolved solids (TDS) and electro conductivity (EC). Whereas protein content and C/N ratio showed less relationship with the soaking properties, but they had a positive correlation with TDS and EC. From the results, it was considered that high values of TDS and EC in the seeds of high temperature were mainly due to the incomplete conversion of assimilates into storage compounds. However, sugar content showed less influence on the soaking properties and the values of TDS and EC.