• Horticultural Science & Technology
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• v.34 no.1
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• pp.77-83
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• 2016

The measurement of total fresh weight of plants provides an essential indicator of crop growth for monitoring production. To measure fresh weight without damaging the vegetation, image-based methods have been developed, but they have limitations. In addition, the total plant fresh weight is difficult to measure directly in hydroponic cultivation systems because of the amount of nutrient solution. This study aimed to develop a real-time, precise method to measure the total fresh weight of Romaine lettuce (Lactuca sativa L. cv. Asia Heuk Romaine) with growth stage in a plant factory using a nutrient film technique. The total weight of the channel, amount of residual nutrient solution in the channel, and fresh shoot and root weights of the plants were measured every 7 days after transplanting. The initial weight of the channel during nutrient solution supply (Wi) and its weight change per second just after the nutrient solution supply stopped were also measured. When no more draining occurred, the final weight of the channel (Ws) and the amount of residual nutrient solution in the channel were measured. The time constant (${\tau}$) was calculated by considering the transient values of Wi and Ws. The relationship of Wi, Ws, ${\tau}$, and fresh weight was quantitatively analyzed. After the nutrient solution supply stopped, the change in the channel weight exponentially decreased. The nutrient solution in the channel slowly drained as the root weight in the channel increased. Large differences were observed between the actual fresh weight of the plant and the predicted value because the channel included residual nutrient solution. These differences were difficult to predict with growth stage but a model with the time constant showed the highest accuracy. The real-time fresh weight could be calculated from Wi, Ws, and ${\tau}$ with growth stage.

• Current Research on Agriculture and Life Sciences
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• v.30 no.2
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• pp.68-75
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• 2012

This study was conducted to monitor the yields of useful substances extracted from Inonotus obliquus. Optimization of ultrasonic-assisted extraction process was carried out by using response surface methodology under different extraction conditions. A central composite design was applied to investigate the effects of independent variables such as extraction time ($X_1$), ethanol concentration ($X_2$) and extraction temperature ($X_3$) on dependent variables such as soluble solid yield ($Y_1$), total phenol contents ($Y_2$), total flavonoid contents ($Y_3$) and browning color($Y_4$). Soluble solid yield was affected by ethanol concentration and extraction temperature. The maximum soluble solid yield was 18.02% at 20.47 min ($X_1$), 42.85% ($X_2$) and $69.57^{\circ}C$ ($X_3$) in saddle point. Total phenol contents were highly affected by ethanol concentration and extraction temperature. The maximum total phenol contents were 71.57mg GAE/g at 21.60min ($X_1$), 45.19% ($X_2$), $69.68^{\circ}C$ ($X_3$). The electron donating ability was affected by extraction temperature and extraction time. Total flavonoid contents were affected by only extraction temperature. The maximum total flavonoid contents were 35.98 mg RE/g at 22.53min ($X_1$), 46.37% ($X_2$), $69.56^{\circ}C$ ($X_3$) in saddle point. The browning color was highly affected by extraction time, ethanol concentration and extraction temperature. The maximum browning color was at 22.00 min ($X_1$), 46.89% ($X_2$), $69.71^{\circ}C$ ($X_3$) in saddle point. As a result, the optimum extraction conditions were predicted; extraction time of 21.50 min, ethanol concentration of 44.87% and extraction temperature of $69.635^{\circ}C$.

• Journal of Korean Society of Forest Science
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• v.34 no.1
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• pp.21-30
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• 1977

Japanese larch (Larix leptolepis) is one of main timber species in Korea that could find much plantation and growing stands on all over the country. It is thought to be in meaningful that a guiding diagram for density control of Japanese larch stands is made to estimate easily the density conditions in the quantitaive, ecological and economic viewpoint. Sample plots for this study are selected from the stands that have not been thinned in recent years, and mean height, mean diameter, dominant height, tree numbers per hectare and stem volume of mean tree are calculated from the each sample plots among total 165 plots In this study, especially, the theory of slenderness of mean tree are applied, that have been identified through the results of the spacing trial. Relative growth characteristics of this species are calculated from the general logistic curve and its formula is $Y=ax^b$. Relatwion between the measured items are found out as follows: 1. Relation between the mean height and tree numbers per hectare by slender class is showing the high correlation as table 1 and fig. 2, and between mean diameter and tree numbers per hectare is also high correlation as table 1 and fig 3. 2. The stem volume can be correctly estimated from height in case that slender class may be known, as showing in table 3 and fig. 4. 3. The stem volume can be more correctly estimated from the relation with $D^2H$ as formula, $Log_e\;V=0.9569\;Log_eD^2H-9.8431$, and relation between stem volume of single tree or volume per hectare and tree numbers per hectare are as following formulas: $Log_e$ stem volume=9.5026-1.6800 $Log_e$ tree numbers per hectare $Log_e$ stem volume per hectare=9.4911-0.6784 $Log_e$ tree numbers per hectare. Stem volume of mean tree, tree numbers per hectare and stem volume per hectare correspond to the mean tree height are calculated to slender class as table 5, 6, 7. Through the above steps, the diagram for density control of Japanese larch are produced as fig. 9. It is thought that this diagram could be applied to control the density of Japanese larch stands.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.4 s.54
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• pp.337-342
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• 2005

The aim of this study was to evaluate the influence of different skin care ingredient concentrations on the effect of polyols and oils on the human skin moisturization and skin surface roughness. Polyols and oils were essential ingredients to make a skin care formulation. But these were still not understood how much concentration(s) were tested on human skin in the aspect of efficacy and sensory. We studied to examine various concentrations of ingredient by cosmetic companies using noninvasive methods. Polyols were composed of glycerol and butylene glycol (BG) as 1:1 ratio, and oils were hydrogenated polydecene, cetyl ethylhexanoate and pentaerythrityl tetraethylhexanoate (PTO(R), Stearinerie Dubois Fils Co., France) as 1:1:1 ratio. All compounds were tested $0{\sim}27%dml$ Polyols and $0{\sim}35%dml$ oils in O/W emulsions. We investigated the effect of water contents and the effect of stratum corneum roughness in forearm skin after application of compounds. Water contents of the skin measured by skin capacitance and skin surface roughness measured visual scoring of skin surface biopsy through the scanning electron microscopy. Water contents of the skin were highly related to amount of polyols (to 20%) and oils (to 12%). Correlation coefficients were 0.971 and 0.985 respectively (p<0.01), 2 h after application. Skin surface roughness was positively correlated with polyol contents in concentration dependent manner, and depend on oils up to 6%. The ratio of coefficient was 2.5 to 1 (polyol to oils) by regression analysis. Further studies will be conducted with other ingredients such as surfactants, lipids and aqueous materials, and with ether methods for noninvasive measurement.

• Food Science and Preservation
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• v.16 no.4
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• pp.472-481
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• 2009

Response surface methodology (RSM) is frequently used for optimization studies. In the present work, RSM was used to determine the antimicrobial activitiesof grapefruit seed extract (GFSE) and a lactic acid mixture (LA) against Staphylococcus aureus, Bacillus cereus, Escherichia coli, Salmonella typhimurium, Pseudomonas fluorescens, and Vibrio parahaemolyticus. A central composite design was used to investigate the effects of independent variables on dependent parameters. One set of antimicrobial preparations included mixtures of 1% (w/w) GFSE and 10% (w/w) LA, in which the relative proportions of component antimicrobials varied between 0 and 100%. In further experiments, the relative proportions were between 20% and 100%. Antimicrobial effects against various microorganisms were mathematically encoded for analysis. The codes are given in parentheses after the bacterial names, and were S. aureus ($Y_1$), B. cereus ($Y_2$), E. coli ($Y_3$), S. typhimurium ($Y_4$), P. fluorescens ($Y_5$), and V. parahaemolyticus ($Y_6$). The optimum antimicrobial activity of the 1% (w/w) GFSE:10% (w/w) LA mixture against each microorganism was obtained by superimposing contour plots ofantimicrobial activities on measures of response obtained under various conditions. The optimum rangesfor maximum antimicrobial activity of a mixture with a ratio of 1:10 (by weight) GFSE and LA were 35.73:64.27 and 56.58:43.42 (v/v), and the optimum mixture ratio was 51.70-100%. Under the tested conditions (a ratio of 1% [w/w] GFSE to 10% [w/w] LA of 40:60, and a concentration of 1% [w/w] GFSE and 10% [w/w] LA, 70% of the highest value tested), and within optimum antimicrobial activity ranges, the antimicrobial activities of the 1% (w/w) GFSE:10% (w/w) LA mixture against S. aureus ($Y_1$), B. cereus ($Y_2$), E. coli ($Y_3$), S. typhimurium ($Y_4$), P. fluorescens ($Y_5$), and V. parahaemolyticus ($Y_6$) were 24.55, 25.22, 20.20, 22.49, 23.89, and 28.04 mm, respectively. The predicted values at optimum conditions were similar to experimental values.

• Food Science and Preservation
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• v.17 no.5
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• pp.659-666
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• 2010

A central composite design was used to investigate the effects of the three independent variables of extraction temperature ($X_1$), ethanol concentration ($X_2$), and extraction time ($X_3$), on dependent variables including yield ($Y_1$), total phenol levels ($Y_2$), electron-donating ability ($Y_3$), brownness ($Y_4$), and reducing sugar content ($Y_5$) of Vitis Coignetiae. Yield was affected by extraction temperature and time. The maximum yield was obtained at $91.62^{\circ}C(X_1)$, and, 25.37% (w/v) ethanol ($X_2$), after 317.70 min of extraction ($X_3$), evident as a saddle when displayed graphically. Total phenol levels were essentially unaffected by extraction temperature or ethanol concentration, but were highly influenced by extraction time. The maximum total phenol levels was 4,763.46 GAE mg/100 g obtained at $88.20^{\circ}C(X_1)$, and 47.79% (w/v) ethanol ($X_2$), after 349.32 min ($X_3$) of extraction. Electron-donating ability (EDA) was affected by extraction temperature and time. Maximum EDA was 55.90% at $86.72^{\circ}C(X_1)$, 50.61% (w/v) ethanol ($X_2$), and 265.96 min ($X_3$) of extration time, again shown by a graphical saddle. Brownness was affected by extraction time. The maximum extent of brown coloration was obtained at $82.66^{\circ}C(X_1)$, 99.27% (w/v) ethanol ($X_2$), and 252.63 min of extraction time ($X_3$), once again shown by graphical saddle. The maximum reducing sugar content was obtained at $96.24^{\circ}C(X_1)$, 22.59% (w/v) ethanol ($X_2$), and 216.06 min extraction time($X_3$).

• Food Engineering Progress
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• v.14 no.2
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• pp.92-98
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• 2010

In this study, various active functional components in Chinese Quince were extracted by solvent extraction method. A central composit design for optimization was applied to investigate the effects of independent variables such as solvent to sample ratio ($X_{1}$), extraction temperature ($X_{2}$), and extraction time ($X_{3}$) on the soluble solid contents ($Y_{1}$), total phenols ($Y_{2}$), electron donating ability ($Y_{3}$), browning color ($Y_{4}$) and reducing sugar contents ($Y_{5}$). It was found that extraction temperature and extraction time were the main effective factors in this extraction process. The maximum soluble solid contents of 35.77% was obtained at 26.38 mL/g ($X_{1}$), 72.82$^{\circ}C$ ($X_{2}$) and 74.86 min ($X_{3}$) in saddle point. Total phenols were rarely affected by solvent ratio and extraction time, but it was affected by extraction temperature. The maximum total phenols of 20.70% was obtained at 22.61 mL/g ($X_{1}$), 84.49$^{\circ}C$ ($X_{2}$), 77.25 min ($X_{3}$) in saddle point. The electron donating ability was affected by extraction time. The maximum electron donating ability of 94.12% was obtained at 10.65 mL/g ($X_{1}$), 67.78$^{\circ}C$ ($X_{2}$), 96.75 min ($X_{3}$) in saddle point. The maximum browning color of 0.32% was obtained at 23.77 mL/g ($X_{1}$), 87.27$^{\circ}C$ ($X_{2}$), 96.68 min ($X_{3}$) in saddle point. The maximum value of reducing sugar content of 10.55% was obtained at 26.83 mL/g ($X_{1}$), 82.167$^{\circ}C$ ($X_{2}$), 81.94 min ($X_{3}$). Reducing sugar content was affected by extraction time.

• Food Engineering Progress
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• v.13 no.1
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• pp.8-15
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• 2009

This study was investigated on optimal conditions of the functional activities of ${\beta}$-glucan which was extracted from rice bran (RB) and rice germ (RG) using response surface methodology. The extraction temperature was varied in the $80-100^{\circ}C$, the extraction time between 2-10 min, and the ethanol concentration was in the interval of 30-70%. A central composite design was applied to investigate the effects of independent variables of extraction temperature ($X_1$), extraction time ($X_2$) and ethanol concentration ($X_3$) on dependent variables such as electron donating ability of RB ($Y_1$), electron donating ability of RG ($Y_2$), total phenolics of RB ($Y_3$), total phenolics of RG ($Y_4$), ${\beta}$-glucan contents of RB ($Y_5$) and ${\beta}$-glucan contents of RG ($Y_6$). As a result, the highest $Y_1$ level was 84.02% at $92.60^{\circ}C$, 2.75 min and 60.41% in saddle point. This value was affected by extraction temperature (P<0.05). The value of $Y_2$ was found to be the highest at $87.52^{\circ}C$, 2.23 min and 54.40% in saddle point. The highest $Y_3$ level was $98.56^{\circ}C$, 6.69 min and 40.26% in saddle point, and this extraction was greatly influenced by extraction temperature (P<0.01) and ethanol concentration (P<0.05). The value of $Y_4$ was found to be highest at $95.73^{\circ}C$, 9.19 min and 53.67% in minimum point. The value of $Y_5$ was found to be the highest at $96.23^{\circ}C$, 7.70 min and 63.69% in saddle point. The value of $Y_6$ was found to be highest at $87.82^{\circ}C$, 2.10 min and 50.03% in minimum point, and this extraction was greatly influenced by extraction time (P<0.01).

• Journal of Korea Water Resources Association
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• v.51 no.spc
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• pp.1091-1103
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• 2018

Having knowledge regarding to which region is prone to drought or flood is a crucial issue in water resources planning and management. This could be more challenging when the occurrence of these hazards affected by climate change. In this study the future streamflow during the wet season (July to September) and dry season (October to March) for the twenty first century of South Korea was investigated. This study used the statistics of precipitation, maximum and minimum temperature of one global climate model (i.e., INMCM4) with 2 RCPs (RCP4.5 and RCP8.5) scenarios as inputs for The Precipitation-Runoff Modelling System (PRMS) model. The PRMS model was tested for the historical periods (1966-2016) and then the parameters of model were used to project the future changes of 5 large River basins in Korea for three future periods (2025s, 2055s, and 2085s) compared to the reference period (1976-2005). Then, the different responses in climate and streamflow projection during these two seasons (wet and dry) was investigated. The results showed that under INMCM4 scenario, the occurrence of drought in dry season is projected to be stronger in 2025s than 2055s from decreasing -7.23% (-7.06%) in 2025s to -3.81% (-0.71%) in 2055s for RCP4.5 (RCP8.5). Regarding to the far future (2085s), for RCP 4.5 is projected to increase streamflow in the northern part, and decrease streamflow in the southern part (-3.24%), however under RCP8.5 almost all basins are vulnerable to drought, especially in the southern part (-16.51%). Also, during the wet season both increasing (Almost in northern and western part) and decreasing (almost in the southern part) in streamflow relative to the reference period are projected for all periods and RCPs under INMCM4 scenario.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.5
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• pp.71-78
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• 2021

Green areas and the area of available horizontal surfaces are gradually decreasing due to the overcrowding of buildings. It is adversely affecting the urban climate and ecosystem. However, the recognition of the importance of green areas is gradually increasing. As a result, the importance of wall greening using vertical surfaces is growing. However, despite the fact that domestic wall greening guidelines and institutions related to orientations restrict planting. there was no study to determine whether there were actual differences in plant growth due to orientations. Therefore, this study compared and analyzed the plant growth characteristics by orientations to apply actual wall greening to cities. The experiment was conducted from May to September 2020. First of all, three octave walls were constructed to measure the temperature, the illumination, and the length of the plants once a week. The plants included Parthenocissus tricuspidata, Hedera rhombea, and Euonymus radicans cv. Aueonmarinata Rehd plants. As a result of the study, Parthenocissus tricuspidata was prolific in the north, and Hedera rhombea, and Euonymus radicans cv. Aueonmarinata Rehd plants were prolific in the south. All three types of plants were prolific in June-July, and the Parthenocissus tricuspidata was prolific in grass-growing, and in August, all the walls were 100% covered. Hedera rhombea had the lowest rate of herbaceous growth, and the vertical coverate was also lower at an average of 45%, but among the three plants, the sheath of the horizontal surface coverate was the highest. Euonymus radicans cv. Aueonmarinata Rehd was low in the speed of herbaceous growth, and finally, the walls were 100% covered except for the north and northwest directions. It was found that not all plants used for wall greening show the same growth, and the difference in growth varies more depending on plants than the effect of orientations. Therefore, it is better to identify the characteristics of plant growth and plant suitable plants for each directions.