• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.3
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• pp.75-82
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• 2016

Objective of this experiment was to predict the potential methane production with crop residues at different loading rates. Anaerobic digestion of barley and rapeseed straw substrates for biogas production was performed in Duran bottles at various biomass loading rates with crop residues. Through kinetic model of surface methodology, the methane production was fitted to a Gompertz equation. For the biogas production at mesophilic digestion with crop residues, it was observed that maximum yield was 37.2 and 28.0 mL/g at 6.8 and 7.5 days after digestion with 1% biomass loading rates of barley and rapeseed straws, respectively. For the methane content of mesophilic digestion, there were highest at 61.7% after 5.5 days and 75.0% after 3.4 days of digestion with barley and rapeseed straw on both 5% biomass loading rates, respectively. The maximum methane production potentials were 159.59 mL/g for 1% barley straw and 156.62 mL/g for 3% rapeseed straw at mesophilic digestion. Overall, it would be strongly recommended that biomass loading rate was an optimum rate at mesophilic digestion for using 1% barley and 3% rapeseed straws for feed stocks.

• Korean Journal of Food Science and Technology
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• v.40 no.3
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• pp.283-289
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• 2008

This study used response surface methodology (RSM) in an effort to optimize the hot water extraction conditions of dandelion leaves in order to increase antioxidant activity in the extract. A central composite design was applied to investigate the effects of independent variables, which included the ratio of solvent to sample ($X_1$), extraction temperature ($X_2$), and extraction time ($X_3$), on dependent variables of the extracts, including soluble solid ($Y_1$), total polyphenols ($Y_2$), total flavonoid ($Y_3$), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability ($Y_4$), 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging ability ($Y_5$), and superoxide radical scavenging ability ($Y_6$). The estimated optimal conditions were as follows: $83.77{\pm}1.07^{\circ}C$ of the extraction temperature, $20.85{\pm}0.24 mL/g$ of solvent per sample, and $1.59{\pm}0.12$ hr of extraction time. At the optimal conditions, the predicted characteristic values were: a yield of 38.98%, a total polyphenol level of $74.28{\mu}g/mg$, a total flavonoid level of $74.00{\mu}g/mg$, a DPPH radical scavenging ability ($IC_{50}$) of 0.14 mg/mL, a ABTS radical scavenging ability ($IC_{50}$) of 3.24 mg/mL, and a superoxide radical scavenging ability ($IC_{50}$) of 2.49 mg/mL.

• Journal of the Korean Society of Food Culture
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• v.14 no.1
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• pp.49-55
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• 1999

This study was to investigate the physicochemical and sensory characteristics of snack with various amounts Cham chwi and oil. This result was used to determine the optimum condition of adding levels of Cham chwi and oil. Flavor, crispness, greasiness, oil absorption, expansion rate were selected as the physicochemical and sensory characteristics to determine the optimum conditions of the amount of Cham chwi and oil. The predicted values were obtained by the regression method of RSM(response surface methodology). Conditions were standardized with maximum range of expansion rate when expected value of crispness was more than five and expected value of greasiness was less five. The optimum conditions of Cham chwi snack was established as the 8.6% of Cham chwi and 7.6% of oil.

• Journal of the Korean Society of Food Culture
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• v.17 no.5
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• pp.653-662
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• 2002

Korean native Perilla Jangachi (salted and fermented vegetable) is popular and well-known but little study on its composition and most palatable condition has been reported. This study was performed to observe the change in the contents of chemical components and sensory evaluation of Perilla Jangachi which was prepared through two processing. First, as a pretreatment, Perilla leaves were soaked in salt water. The optimal level of salt concentration and soaking time (salt 4%, soaking time 42hours) was determined. Second, soaked Perilla Jangachi was steamed and then fermented in various ingredients like soy sauce, sugar, onion and so on. In this study, Perilla Jangachi was made by 3 levels of steaming time(30 seconds, 60 seconds, 90 seconds) and onion contents (10%, 30%, 50%). The optimal level of onion contents and steaming time was determined with the results of sensory evaluation by response surface methodology and analysis of composition. Sodium contents were decreased as the levels of onion contents were increased. Flavonoids contents weren't increased although contents of onion were increased. But they were influenced on steaming time that as the levels of steaming time were shortened, flavonoids contents were increased. To lengthen the shelf-life of Perilla Jangachi, the activities of enzyme peroxidase - which changes Jangachi's quality bad - by various levels of steaming time were measured. After steaming 50 seconds, peroxidase became inactive. Reducing sugar contents were decreased relying on either increased steaming time and onion contents. While steaming 30 seconds and 10% onion contents, the content of reducing sugar was 0.858% but steaming 90 seconds and 50% onion contents, it became 0.372%. Among the sensory attributes, brownness was increased as onion contents increased and steaming more than 60 seconds. Saltiness, sweetness, perilla flavor were greater relying on decreased onion contents. Toughness was decreased as both the amounts of onion and steaming time were increased. With this results, the most optimal adding level of onion content and steaming time was determined. Steaming 72 seconds and adding onion 27% was established as a optimal condition of Perilla Jangachi.

• Korean journal of food and cookery science
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• v.25 no.1
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• pp.106-118
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• 2009

This study was to investigated optimum preparation conditions for Gugija Heukimja jook by response surface methodology (RSM). The important materials used for the Gugija Heukimja product were Lycium chinese, Seasamum indicum L., Ziziphus jujuba Mill. and rice. Moisture content, crude protein, crude fat, crude ash and crude fiber content were 15.62, 16.60, 13.62, 4.93 and 11.17% for Lycium chinese, 3.62, 20.94, 43.56, 5.67 and 10.72% for Seasamum indicum L., 24.12, 5.38, 0.73, 2.30 and 1.25% for Ziziphus jujuba Mill., and 12.36, 6.98, 0.46, 0.43 and 0.41% for rice, respectively. Optimal extraction conditions of brix, color, pH and total acidity in the materials for Gugija Heukimja jook were temperature $80^{\circ}C$, water volume 850 mL and extraction time of 63 min. The spreadability of jook with Lycium chinese and Ziziphus jujuba Mill. extracts was the highest when black sesame was 12 g pH was the lowest when black sesame was 9 g. PH showed a significant difference when the added black sesame ratio changed. The 'value L' of chromaticity was lower with an increase of the black sesame ratio, 'value a' was higher with an increase of the black sesame ratio, 'value b' was lower with an increase of the black sesame ratio. Brix was lower when black sesame in jook was added. Total acidity was highest (7.27%) when black sesame was 12 g. The degree of gelatinization tended to be lower with additional black sesame. Higher scores of sensory evaluation were found for the product containing 9 g black sesame with Lycii furctus and Ziziphus jujuba Mill. extracts ompared to the other samples with 3 and 6g. No significant difference in taste occurred for Gugija Heukimja jook prepared with over 9 g black sesame, while a great difference showed in color, pH and total acid. Therefore, the Gugija Heukimja jook prepared under the optimal conditions of 9 g black sesame with Lycium chinese and Ziziphus jujuba Mill. extracts exhibited higher qualities. Gugija Heukimja jook can use the easier for Yacksun jook. It is expected to become functional in the product's development.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.3
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• pp.393-400
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• 2009

Recently demand for the 3D modeling technology to reconstruct real world is getting increasing. However, existing geospatial data are mainly based on the 2D space. In addition, most of the geospatial data provide geometric information only. In consequence, there are limits in various applications to utilize information from those data and to reconstruct the real world in 3D space. Therefore, it is required to develop efficient 3D mapping methodology and data for- mat to establish geospatial database. Especially digital elevation model(DEM) is one of the essential geospatial data, however, DEM provides only spatially distributed 3D coordinates of the natural and artificial surfaces. Moreover, most of DEMs are generated without considering terrain properties such as surface roughness, terrain type, spatial resolution, feature and so on. This paper suggests adaptive and flexible geospatial data format that has possibility to include various information such as terrain characteristics, multiple resolutions, interpolation methods, break line information, model keypoints, and other physical property. The study area was categorized into mountainous area, gently rolling area, and flat area by taking the terrain characteristics into account with respect to terrain roughness. Different resolutions and interpolation methods were applied to each area. Finally, a 3D digital map derived from aerial photographs was integrated with the geospatial data and visualized.

• Economic and Environmental Geology
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• v.35 no.2
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• pp.137-147
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• 2002

Natural geological and environmental processes reflect to element abundances in geological materials on the surface. This study aims to elucidate a possibility of geostatistical application to differentiate geochemical anomalies affected by anthropogenic and geogenic factors. A regional geochemical map was produced using 'inverse distance weight interpolation' method for analytical results of stream sediments «150 11m) which were collected from 2,290 first- to second-order streams over the whole Gyeonggi Province. The Jurassic granitic batholith in the southeastern province was selected as a target for the geostatistical examination. Factor analysis was conducted using 22 elements for stream sediments from 445 drainage basins over the granitic body. Co, Cr, Sc, MgO, Fe$_{2}$O$_{3}$, V, and Ni were grouped with high correlation coefficients and the depletion of the components may reflect the whole-rock chemistry of the granite. Regression analysis was done using Co, Cr, and Sc as dependent variables and other six components as independent variables, and the results were drawn as maps. The maps acquired generally show quite similar distribution patterns with those of concentrations of each variable. The similarity in the spatial patterns between the two maps indicates that the application of regression statistics can be valid for the interpretation of regional geochemical data. However, some components show local discrepancies which may be influenced by secondary factors regardless of the basement lithology. The regression analysis may be effective in extracting local geochemical anomalies which may reflect rather anthropogenic pollutions than geogenic influences.

• Economic and Environmental Geology
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• v.40 no.5
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• pp.563-574
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• 2007

Laser induced breakdown spectroscopy (LIBS) is a recently developed analytical technique that is based upon the measurement of emission lines generated by atomic species close to the surface of the sample, thus allowing their chemical detection, identification and quantification. With powerful advantages of LIBS compared to the conventional analytical methodology, this technique can be applied in the detection of heavy metals in the field. LIBS allows the rapid analysis by avoiding laborious chemical steps. LES have already been applied for the determination of element concentration in a wide range of materials in the solid, liquid and gaseous phase with simplicity of the instrument and diversity of the analytical application. These feasibility of rapid multi elemental analysis are appealing proprieties for the in-situ analytical technique in geochemical investigation, exploration and environmental analysis. There remain still some limitations to be solved for LIBS to be applied in soil environment as an in-situ analytical technology. We would like to provide the basic principle related to the plasma formation and laser-induced breakdown of sample materials. In addition, the matrix effect, laser properties and the various factors affecting on the analytical signal of LIBS was dealt with to enhance understanding of LIBS through literature review. Ultimately, it was investigated the feasibility of LIBS application in soil environment monitoring by considering the basic idea to enhance the data quality of LIBS including the calibration method for the various effects on the analytical signal of LIBS.

• The Journal of Engineering Geology
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• v.17 no.3
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• pp.393-404
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• 2007

The purpose of this study is to capture the essentials in survey and evaluation scheme which are able to assess the hazard of a rock slope systematically. Statistical analysis are performed on slope instability parameters related to failure of the rock slope. As the slope instability parameters, twelve survey items are considered such as tension crack, surface deformation, deformation of retaining structures, volume of existing failures, angles between strike of discontinuity and strike of cut slope face, angles between dip of discontinuity and dip of cut slope face, discontinuity condition, cut slope angle, rainfall or ground water level, excavation condition, drainage condition, reinforcement. A total of 233 road cut slopes located in Gyeongnam were considered. The stability of the road cut slopes were evaluated by estimating the slope instability index(SII) and corresponding stability rank. 126 rock slopes were selected to analyze statistical relation between SII and slope instability parameters. The multiple regression analysis was applied to derive statistical models which are able to predict the SII and corresponding slope stability rank. Also, its applicability was explored to predict the slope failures using the variables of slope instability parameters. The results obtained in this study clearly show that the methodology given in this paper have strong capabilities to evaluate the failures of the road cut slope effectively.

• Korean Journal of Food Science and Technology
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• v.47 no.3
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• pp.321-327
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• 2015

The optimal condition for preparation of powdered calcium acetate (LCCA) which has high solubility, from calcined powder (LCCP) of the littleneck clam shell by response surface methodology (RSM) was examined. Increased molar ratio of LCCP led to reduced solubility, yield, color values, and overall quality. The critical values of multiple response optimization of independent variables were 2.57 M of acetic acid and 1.57 M of LCCP. The actual values (pH 7.0, 96.1% for solubility, and 220.9% for yield) under the optimized condition were similar to the predicted values. LCCA showed strong buffering capacity between pH 4.89 and 4.92 on addition of ~2 mL of 1 N HCl. The calcium content and solubility of LCCA were 21.9-23.0 g/100 g and 96.1-100.1%, respectively. The FT-IR and XRD patterns of LCCA were identified as calcium acetate monohydrate, and FESEM images revealed an irregular and rod-like microstructure.