• Journal of the Korean Applied Science and Technology
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• v.29 no.2
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• pp.205-213
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• 2012

In this study, the stability of cream containing the ethyl acetate fraction of C. obtusa leaf extract was evaluated. The pH, viscosity, and absorbance were measured under the 4 different temperatures (4, 25, 37 and $45^{\circ}C$) and under the sun light during the 12 weeks. The control cream without containing the extract did not show pH change under the different temperatures mentioned above. However, the pH of the cream with the extract was decreased 0.11 at $4^{\circ}C$ and $25^{\circ}C$. Under the $37^{\circ}C$, $45^{\circ}C$ and sun light condition, the pH was decreased 0.55, 0.84 and 0.59, respectively. After treating the cream for 12 weeks under the different temperatures, the viscosity was measured for the cream containing the extract and control cream. The values were decreased by 2,404 cPs in average compared to the initial value for the former and control cream were decreased by 1,296 cPs in average for the latter. On the other hand, the viscosity of control cream treated under the $45^{\circ}C$ for 12 weeks was decreased (1,915 cPs) relative to the cream containing the extract, which showed 3,810 cPs decrease in viscosity. The cream containing the extract did not show absorbance change at $4^{\circ}C{\sim}37^{\circ}C$ for 12 weeks. Instead, the absorbance of the cream treated under $45^{\circ}C$ and sun light condition was decreased 32.5 % and 35.2 %, respectively. This decrease in absorbance is relatively small compared to the 54.8 % decrease of the extract sampled from the cream using ethanol solution. This indicates that the extract is stabilized in the cream. In addition, any change in color or smell was not observed through 12 weeks of the experimental time period. Also physical changes as creaming and cohesion were not shown. The results show that the cream containing C. obtusa leaf extract was relatively stable. However, it is concluded that it is still not clear in the stability of the cream containing the extract when it is stored for a long time. Accordingly, it is suggested that further study is needed for the application of the extract to cosmetics.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.9
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• pp.351-360
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• 2018

The LWR (Locally Weighted Regression) model, which is traditionally a lazy learning model, is designed to obtain the solution of the prediction according to the input variable, the query point, and it is a kind of the regression equation in the short interval obtained as a result of the learning that gives a higher weight value closer to the query point. We study on an incremental ensemble learning approach for LWR, a form of lazy learning and memory-based learning. The proposed incremental ensemble learning method of LWR is to sequentially generate and integrate LWR models over time using a genetic algorithm to obtain a solution of a specific query point. The weaknesses of existing LWR models are that multiple LWR models can be generated based on the indicator function and data sample selection, and the quality of the predictions can also vary depending on this model. However, no research has been conducted to solve the problem of selection or combination of multiple LWR models. In this study, after generating the initial LWR model according to the indicator function and the sample data set, we iterate evolution learning process to obtain the proper indicator function and assess the LWR models applied to the other sample data sets to overcome the data set bias. We adopt Eager learning method to generate and store LWR model gradually when data is generated for all sections. In order to obtain a prediction solution at a specific point in time, an LWR model is generated based on newly generated data within a predetermined interval and then combined with existing LWR models in a section using a genetic algorithm. The proposed method shows better results than the method of selecting multiple LWR models using the simple average method. The results of this study are compared with the predicted results using multiple regression analysis by applying the real data such as the amount of traffic per hour in a specific area and hourly sales of a resting place of the highway, etc.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.4
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• pp.231-238
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• 2007

In the previous study, the anti-oxidant activity of extract/fraction of Sueada asparagoides (SA) was investigated and the results showed that the ethylacetate (EtOAc) fraction and its aglycone fraction had the best performance on the free radical scavenging activity, reactive oxygen species scavenging (ROS) activity and cell protective activity (J. Soc. Cosme. Scientists Korea, 33(3), 145 (2007)). In this study, the stability of cream containing 0.3% SA EtOAc extract (called extract below) was evaluated. pH, viscosity and absorbance (363 nm) were measured under the 4 different temperatures ($0^{\circ}C,\;25{\circ}C,\;37{\circ}C\;and\;45{\circ}C$) and under the sun light at the 4 week intervals during the 12 weeks in total. The control cream without containing the extract did not show pH change under the different temperatures mentioned above. However, the pH of the cream the extract was decreased 0.08 at the temperature ranges of $0^{\circ}C\;to\;37^{\circ}C$. Under the $45^{\circ}C$ and sun light condition, the pH was decreased 0.51 and 0.66, respectively. The cream containing the extract did not show absorbance change at the temperature ranges of 0 to $37^{\circ}C$ for 12 weeks. Instead, the absorbance of the cream treated under $45^{\circ}C$ and sun light condition was decreased 7.6 % and 7.4 %, respectively. This decrease in absorbance is relatively small compared to the 48.3 % decrease of the extract sampled from the cream using ethanol solution. This indicates that the extract is stabilized in the cream. After treating the cream for 12 weeks under the different temperatures, the viscosity was measured for the cream containing the extract and control cream. The values were increased by 1,748 cPs in average compared to the initial value for the former and by 951 cPs in average for the latter. On the other hand, the viscosity of control cream treated under the sun light for 12 weeks was significantly decreased (4,022 cPs) relative to the cream containing the extract, which showed 2,484 cPs increase in viscosity. This indicates that the SA extract contributes to the stability of the emulsion product by protective effect to maintain the viscosity of the cream against sun light. In addition, any change in color or smell was not observed through 12 weeks of the experimental time period. Thus, it is concluded that it is still not clear in the stability of the cream containing the extract when it is stored for the long time. Accordingly, it is suggested that further study is needed to provide more information to the manufactures, who are seeking for the application of the extract to improve the anti-oxidant activity and stability of cosmetic products.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.3
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• pp.209-214
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• 2010

Purpose: The purpose of this study was to investigate whether the re-osseointegration of the implants that had mechanical unscrewing possibly occurred or not. Furthermore, if it happened, the degree of re-osseointegration was evaluated by comparing with previous osseointegration. Materials and methods: The smooth implant (commercial pure titanium 99%) specimens, whose diameter and length was 3.75 mm, 4 mm, respectively were produced. Two implants were inserted into each tibia of 7 New Zealand female white rabbits weighing at least 3.0 kg. The torque removal force for each implant after 6 weeks of implants placement was measured and included in group I. The torque removal forces were assessed after the fixtures were re-screwed to original position and the subjects were allowed to have 4 more weeks for healing and included in group II. One rabbit was sacrificed after first measurement and produced 4 slide specimens in group I, and two rabbits were sacrificed after 2nd measurement, 7 slide specimens, in group II for histomorphologic investigations. All slide specimens were assessed based on the proportion of BIC (bone-implant contact) as well as CBa (Bone area in the cortical passage) value produced by counting the screw threads embedded in the compact bones under the optical microscopic analysis (${\times}20$). Statistical analysis was conducted to evaluate the torque removal force, BIC and CBa between group I and II. Results: As for the torque removal force, the result was $10.8{\pm}3.6$ Ncm for group I and $20.2{\pm}9.7$ Ncm for group II. Furthermore, the torque removal force of group II increased by 98.1% in average compared to group I (P<.05). On the other hand, histomorphologic analysis displayed that there was no statistical significance in BIC and CBa values between group I and the group II (P>.05), and RT/BIC and RT/CBa between group I and group II were statistically significant (P<.05). Conclusion: It is possible to obtain more substantial re-osseointegration within shorter periods than the period needed for the initial osseointegration in case of iatrogenically unscrewed implants.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.3
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• pp.366-370
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• 2007

Wild grapes contain various organic acids, vitamins, and inorganic salts compared to other various fruits. Their anthocyanin compounds are also known to have excellent effects in preventing cancers and heart diseases. Wild grapes are supposed to be a superior material for wine fermentation. This study was performed for searching optimum conditions for producing wild grape wines to improve their quality and taste. Four wild strains were isolated from Muscat Bailey A, ‘Kyoho’ grapevine, and wild grapes. For wild grape wine production, an optimum initial sugar concentration was $24^{\circ}Brix$ and an optimum temperature was $24^{\circ}C$. Sensory characteristics of the wild grape wine were evaluated for incense, sour taste, astringency, and sweet taste. Quality properties of the wild grape wine produced under the optimized fermentation conditions were analyzed. Total sugar, polyphenol contents, and acidity of the wild grape wine were 50.00 mg/mL, 25.30 mg/mL, and 0.95%, showing higher value than those of commercial grape wines. Amino acids, tannins, alcohol contents, and pH were 1.80 mg/mL, 1.88 mg/mL, 12%, and 3.59, respectively. The optimum fermentation conditions can be used to improve quality of the wild grape wine.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.268-275
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• 2017

The photosynthetic rates of crops depend on growth environment factors, such as light intensity and temperature, and their photosynthetic efficiencies vary with growth stage. The objective of this study was to compare two different models expressing canopy photosynthetic rates of romaine lettuce (Lactuca sativa L., cv. Asia Heuk romaine) using three variables of light intensity, temperature, and growth stage. The canopy photosynthetic rates of the plants were measured 4, 7, 14, 21, and 28 days after transplanting at closed acrylic chambers ($1.0{\times}0.8{\times}0.5m$) using light-emitting diodes, in which indoor temperature and light intensity were designed to change from 19 to $28^{\circ}C$ and 50 to $500{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, respectively. At an initial $CO_2$ concentration of $2,000{\mu}mol{\cdot}mol^{-1}$, the canopy photosynthetic rate began to be calculated with $CO_2$ decrement over time. A simple multiplication model expressed by simply multiplying three single-variable models and a modified rectangular hyperbola model were compared. The modified rectangular hyperbola model additionally included photochemical efficiency, carboxylation conductance, and dark respiration which vary with temperature and growth stage. In validation, $R^2$ value was 0.849 in the simple multiplication model, while it increased to 0.861 in the modified rectangular hyperbola model. It was found that the modified rectangular hyperbola model was more suitable than the simple multiplication model in expressing the canopy photosynthetic rates affected by environmental factors (light Intensity and temperature) and growth factor (growth stage) in plant factory modules.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.1
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• pp.19-25
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• 2009

Purpose: The aims of this study were to analyze correlation between the maximum standardized uptake value (SUVmax) of 2-[F-18]-fluoro-2-deoxy-d-glucose (FDG) on positron emission computed tomography (PET-CT) scan and the degree of contrast enhancement on computed tomography (CT) scan in lung cancers, and to recognize the difference in SUVmax and CT enhancement between groups of different histopathologic subtypes. Materials and Methods: Our study included 53 patients of pathologically confirmed primary lung cancer, who were performed PET-CT and post-contrast chest CT. We calculated initial and delayed SUVmax (SUV1, SUV2), difference between SUV1 and SUV2 (SUVd), retention index (RI), and the degrees of CT contrast enhancement of lung cancers. We analyzed these variables for subtypes of lung cancers. Results: The values (mean$\pm$ standard deviation) were $8.3{\pm}4.4$ for SUV1, $10.7{\pm}5.7$ for SUV2, $2.4{\pm}1.6$ for SUVd, $30{\pm}14$ for RI and $47.1{\pm}14.8$ HU (Hounsfield Unit) for degree of CT contrast enhancement. The difference of SUV1 and degree of CT enhancement between subtypes was not meaningful. SUV1 showed positive correlations with SUVd (r=0.74, p<0,01) and tumor size (r=0.58, p<0.01), but no significant correlation with degree of CT enhancement (r=0.06, p=0.69). In 10 cases, there was discrepancy in the same mass between the area of highest FDG-uptake and the area of highest contrast enhancement. Conclusion: We suggest that FDG uptake in lung cancer does not have a positive linear correlation with degree of CT enhancement. And there is no significant difference in FDG uptake and degree of CT enhancement between different subtypes of lung cancers.

• Korean journal of food and cookery science
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• v.21 no.5
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• pp.677-684
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• 2005

This study investigated the changes in physicochemical characteristics after 120 days of aging Korean red pepper paste, 'Kochujang', made of minor cereals in substitution for glutinous rice which has been conventionally used as starch source. The cereals used were waxy job's tears, proso millet, sorghum, barley and foxtail millet, Glutinous rice with barley was used as controls. The items determined were water activity, pH, content of amino nitrogen, chromaticity and sensory test. 1. The water activities(Aw) of Kochujang samples were in range of $0.72{\sim}0.82$ at the beginning of fermentation, with Aw barley paste bing the lowest, and Aw of sorghum paste bing the highest. Then Aw were slowly decreased to the range of $0.49{\sim}0.50$ during 120 days of fermentation 2. The pH of the pastes was in range of $4.94{\sim}5.02$ at the initial time of fermentation, and decreased steadily to 4.32{\sim}4.73 at the end. 3. The content of amino nitrogen was in range of $330.9{\sim}340.7\;mg%$ at the early time of fermentation. The highest content, $351{\sim}381\;mg%$, was observed at the 90th day of aging of glutinous rice paste, 105th day of job's tears paste, 75th day each of barley and proso millet, and 60th day each of sorghum and foxtail millet. 4. The Hunter tristimulus values (L, a, b) of all pastes were gradually decreased during fermentation. The value of barley paste was lowest among the pastes. 5. The texture of barley paste in sensory test showed significant difference with other pastes, whereas there were no differences in color, odor, taste and sensory qualities.

• Korean Journal of Food Science and Technology
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• v.38 no.3
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• pp.392-399
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• 2006

In order to develop a new persimmon pickle with a low salt concentration, changes in physicochemical characteristics during soaking of persimmon pickles treated with different organic acids and sugars were investigated at $15^{\circ}C$ for 70 days. The pH of persimmon pickles decreased from pH 6.64 at initial stage to pH 3.99 (control group), pH 2.76-3.33 (citric acid treatment, CT), and pH 3.08-3.34 (acetic acid treatment, AT) after 70-days of soaking. Titratable acidity of AT was higher (0.86-1.18%) than that of CT (0.61-0.78%). After 70-days of soaking, salinity of persimmon pickles treated with stevia leaf powder, sodium saccharin, sucrose, and isomalto-oligosaccharide were 4.94-4.96, 4.00-5.15, 2.99-3.31, and 3.03-3.30%, respectively, and 1.54-3.70% lower than that of the control group (6.69%). The hardness of persimmon pickles in all cases was increased up to 20-40-days of soaking and then decreased. L (lightness), a (redness), and b (yellowness) value of persimmon pickles treated with citric acid were higher than those of AT and the control group. Sensory evaluation of persimmon pickles after 70-days of soaking revealed that CT had the highest scores for color, texture, and overall acceptability. These results indicate that the salt concentration of persimmon pickles could be lowered by the addition of citric acid and various sugars during soaking.

• Clean Technology
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• v.12 no.3
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• pp.128-137
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• 2006

The volume change of an ionic liquid and the phase separation behavior of room temperature ionic liquid(RTIL)/organic compound mixture in supercritical carbon dioxide were measured in a high pressure view cell. 1-Butyl-3-methylimidazolium hexafluorophosphate ([bmim][$PF_6$]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][$BF_4$]) was used as ionic liquid(IL). and methanol and dimethyl carbonate were used as organic compound. For a fixed amount of [bmim][$PF_6$] the lower critical endpoint (LCEP) pressure, where the liquid phase is split, decreased as increasing the amount of organic compound. The LCEP pressure became higher as the water content of ionic liquid was higher. However, for water contents above a certain value, no LCEP was formed. LCEP appeared 1.0 MPa higher for a mixture with [bmim][$BF_4$] than with [bmim][$PF_6$]. There was almost no difference in the K-point pressures for different types of ionic liquid and for different amounts of organic liquid. When the concentration of ionic liquid([bmim][$PF_6$]) (IL/(IL+MeOH)) in the initial liquid mixture was larger than 5.9 mol% at the LCEP of the mixture, the volume of $L_1$ because larger than the volume of $L_2$. When it was smaller, however, the volume became smaller, too. The volume change of ionic liquid in the presence of carbon dioxide decreased as increasing the temperature, while it increased as increasing the pressure. For temperatures between 313.15 to 343.15K at 300 bar, it was about 123~125 % of the original volume.