• Korean Journal of Food Science and Technology
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• v.16 no.4
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• pp.463-471
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• 1984

For the eventual alcohol production from uncooked starch, an efficient saccharification process was examined by using the combined action of steeping, pectin depolymerase, ${\alpha}-amylase$ and glucoamylase. The total sugar content of rice, sweet potato and tapioka used were 4.53, 4.26, and 3.92 mmole/g sample. $70\;{\pm}\;10%$ of the total sugar was hydrolyzed when cooked starch was saccharified under the condition which is currently used in industry. The smaller starch particle was used, the more saccharification was obtained. Efficient saccharification was obtained by treatment with 5% $H_2SO_4$ (sample: working volume = 1:2) at $60^{\circ}C$ for 12 hr. Optimization was carried out for the saccharification of uncooked starch by the combined action of pectin depolymerase, ${\alpha}-amylase$, and glucoamylase. The conditions are: pectin depolymerase; pH 4.5, $45^{\circ}C$, 2 hr, ${\alpha}-amylase$; pH 6.0, $60^{\circ}C$, 1 hr, and glucoamylase; pH 3.5, $60^{\circ}C$, 1 hr. Simultaneous treatment of the combined action of macerating, liquifying and saccharifying enzymes yielded better result than stepwise treatment of 3 enzymes. Degrees of saccharification of uncooked tapioka, rice and sweet potato were 82, 90.5, and 84.5%, respectively on the basis of total sugar, under the optimized conditions.

• Journal of the Korean Society of Radiology
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• v.9 no.2
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• pp.67-72
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• 2015

In diagnostic radiology, the use of automatic exposure control device is internationally recommended for diagnosis and optimization. However, if exposed to prolonged radiation is a complicated manufacturing process, there is a problem that occurs decrease of various performance overall brightness sensor, which is commercially available conventional. Therefore, in this study, absorption of X-ray is high, and I want to evaluate the AEC applicability of the sensor of the photoconductor-based production has an easy advantage. Experimental results confirms the possibility of fabrication of the sensor through an increase in the SNR, with the detection efficiency superior, accurate turn-off. In addition, it is confirmed that the experimental results of the transmittance and the latent image, Ghost effect by the light conductor does not appear, in the case of a photoconductor with the exception of the PbO, 80% - and it was confirmed good transmittance of 90%. Therefore, excellent mechanical stability and poor performance due to a change of the doping concentration than the existing products that have been put to practical use, the sensor easy photoconductor based, fabrication and can be applied as AEC sensor is expected.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.1
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• pp.26-31
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• 2018

Objective: This study estimated the genetic parameters for body weight gain and growth curve parameter traits in Korean native chicken (KNC). Methods: A total of 585 $F_1$ chickens were used along with 88 of their $F_0$ birds. Body weights were measured every 2 weeks from hatching to 20 weeks of age to measure weight gain at 2-week intervals. For each individual, a logistic growth curve model was fitted to the longitudinal growth dataset to obtain three growth curve parameters (${\alpha}$, asymptotic final body weight; ${\beta}$, inflection point; and ${\gamma}$, constant scale that was proportional to the overall growth rate). Genetic parameters were estimated based on the linear-mixed model using a restricted maximum likelihood method. Results: Heritability estimates of body weight gain traits were low to high (0.057 to 0.458). Heritability estimates for ${\alpha}$, ${\beta}$, and ${\gamma}$ were $0.211{\pm}0.08$, $0.249{\pm}0.09$, and $0.095{\pm}0.06$, respectively. Both genetic and phenotypic correlations between weight gain traits ranged from -0.527 to 0.993. Genetic and phenotypic correlation between the growth curve parameters and weight gain traits ranged from -0.968 to 0.987. Conclusion: Based on the results of this study population, we suggest that the KNC could be used for selective breeding between 6 and 8 weeks of age to enhance the overall genetic improvement of growth traits. After validation of these results in independent studies, these findings will be useful for further optimization of breeding programs for KNC.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.1
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• pp.1-11
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• 2005

Several Solid Freeform Fabrication Systems(SFFS) are commercialized in a few companies for rapid prototyping. However, they have many technical problems including the limitation of applicable materials. A new method of agile prototyping is required for the recent manufacturing environments of multi-item and small quantity production. The objectives of this paper include the development of a novel method of SFFS, the CAFL/sup VM/(Computer Aided Fabrication of Lamination for Various Material), and the manufacture of the various material samples for the certification of the proposed system and the creation of new application areas. For these objectives, the technologies for a highly accurate robot path control, the optimization of support structure, CAD modeling, adaptive slicing was implemented. However, there is an important problem with the conventional 2D lamination method. That is the inaccuracy of 3D model surface, which is caused by the stair-type surface generated in virtue of vertical 2D cutting. In this paper, We design the new control algorithm that guarantees the constant speed, precise positioning and tangential cutting on the 5DOF SFFS. We develop the tangential cutting algorithm to be controlled with constant speed and successfully implemented in the 5DOF CAFL/sup VM/ system developed in this paper. Finally, this paper confirms its high-performance through the experimental results from the application into CAFL/sup VM/ system.

• Korean Chemical Engineering Research
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• v.46 no.1
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• pp.194-199
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• 2008

In this study, the effective method to esterify the free fatty acids in jatropha oil was examined. Compared to other plant oils, the acid value of jatropha oil was remarkably high, 11.5 mgKOH/g. So direct transesterification by a base catalyst was not suitable for the oil. After the free fatty acids were esterified with methanol, jatropha oil was transesterified. The activities of four solid acid catalysts were tested and Amberlyst-15 showed the best activity for the esterification. After constructing the experiment matrix based on RSM and analyzing the statistical data, the optimal esterification conditions were determined to be 6.79% of methanol and 17.14% of Amberlyst-15. After the pretreatment, jatropha biodiesel was produced by the transesterification using KOH in a pressurized batch reactor. Jatropha biodiesel produced could meet the major specifications of Korean biodiesel standards; 97.35% of FAME, 8.17 h of oxidation stability, 0.125% of total glycerol and $0^{\circ}C$ of CFPP.

• Korean journal of food and cookery science
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• v.32 no.3
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• pp.307-315
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• 2016

Purpose: The central composition design was used to optimize the mixture conditions of black garlic extract. Methods: The response surface methodology (RSM) was carried out from concentration of black garlic extract ($X_1$) and the amount of the black garlic extract ($X_2$) as independent variables, and salts ($Y_1$), reducing sugars ($Y_2$), the content of total phenolic compounds ($Y_3$) and ABTS radical scavenging activity ($Y_4$) as dependent variables. We confirmed the conditions that salinity was minimized and reducing sugar, total phenolic compounds and ABTS radical scavenging activity had maximum values through the response surface analysis. Results: All results had saddle points in originally set up conditions hence, ridge analysis was carried out for narrowing the experimental area. The minimum salt concentration was 16.03% at black garlic extract concentration of $14.84^{\circ}brix$ and contents of 9.26%. Reducing sugar content had maximum of value 7.30 g/mL at $24.58^{\circ}brix$ and contents of 8.08%. Total phenolic compounds contents and ABTS radical scavenging activity had maximum values at black garlic extract concentration of 20.33 and $25.02^{\circ}brix$. The results indicate that addition of black garlic extract contributed to increased reducing sugar, phenolic compounds contents and antioxidant activity of the soy sauce, but the salt concentration was not significantly affected. Conclusion: Based on the results of RSM, the optimum ranges of addition conditions for lowering the salt concentration and, increasing the sensory and functional ability of soy sauce were as follows: black garlic extract concentration of $15-25^{\circ}brix$ and content of 7.8-9.3%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.8
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• pp.986-996
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• 2017

In this study, we optimized fermentation conditions for burdock vinegar by response surface methodology. We confirmed the fermentation characteristics and major components of burdock vinegar. Alcohol fermentation of burdock extract added with 15% apple concentrates for vinegar production was performed. Consequently, 6.4% alcohol was produced after 5 days of fermentation. Central composite design was applied to investigate the effects of two independent variables, fermentation time (5~17 days; X1) and fermentation temperature ($26{\sim}34^{\circ}C$; X2), on fermentation of burdock vinegar. Fermentation conditions were optimized using characteristics of fermentation broth as a dependent variable. Acetic acid contents of dependent variables were 3.85~4.73% during acetic acid fermentation. The correlation coefficient ($R^2$) of the derived equation from the response surface regression for acetic acid contents was 0.9850 with significance level of 1%. Arctiin contents of all fermentation samples were 0.37~0.50 mg/100 mL, with an $R^2$ value of 0.8380 and significance level of 5%. We elicited a regression equation for each variable and superimposed the optimum area of fermentation conditions for characteristics and effective constituent contents of the fermentation broth. The predicted values for the optimum fermentation conditions for burdock vinegar were at $31^{\circ}C$ and 16 days.

• Journal of Bio-Environment Control
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• v.13 no.4
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• pp.209-216
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• 2004

This study was aimed to assess the effects of microclimate factors on lettuce chlorophyll fluorescent responses and to develop an environment control system for plant growth by adopting a simple genetic algorithm. The photosynthetic responses measurements were repeated by changing one factor among six climatic factors at a time. The maximum Fv'/Fm' resulted when the ambient temperature was $21^{\circ}C,\;CO_2$ concentration range of 1,200 to 1,400 ppm, relative humidity of $68\%$, air current speed of $1.4m{\cdot}s^{-1}$, and the temperature of nutrient solution of $20^{\circ}C$. In PPF greater than $140{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, Fv'/Fm' values were decreased. To estimate the effects of combined microclimate factors on plant growth, a photosynthesis efficiency model was developed using principle component analysis for six microclimate factors. Predicted Fv'/Fm' values showed a good agreement to measured ones with an average error of $2.5\%$. In this study, a simple genetic algorithm was applied to the photosynthesis efficiency model for optimal environmental condition for lettuce growth. Air emperature of $22^{\circ}C$, root zone temperature of $19^{\circ}C,\;CO_2$ concentration of 1,400 ppm, air current speed of $1.0m{\cdot}s^{-1}$, PPF of $430{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, and relative humidity of $65\%$ were obtained. It is feasible to control plant environment optimally in response to microclimate changes by using photosynthesis efficiency model combined with genetic algorithm.

• Korean Journal of Plant Tissue Culture
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• v.21 no.2
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• pp.91-97
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• 1994

To improve the productivity of peroxidase (POD) of cell line SP-47 derived from cell suspension cultures of sweet potato (Ipomoea batatas (L) Lam.cv White Star), we optimized culture conditions including the composition and concentration of plant growth regulators and carbon source, and the cell inoculum size. When one g (fr wt) of cells was inoculated into 50 mL TL medium supplemented with l mg/L 2,4-D and 30g/L sucrose in 300 mL Erlenmeyer flask at 25$^{\circ}C$ in the dark (100rpm), the POD activity per g cell dry wt was maximized to be about 6,800 units after 25 days of subculture, which was about 30 times higher than that of intact roots of horseradish plants grown in the greenhouse, but the cell growth was maximum after 15 days of subculture. The protein content per g cell dry wt maintained almost plateau and after 25 days of subculture decreased as culture Proceeded further whereas the POD specific activity (unit/mg protein) was about two times higher after subculture and continuously increased from 12 days to the end of cultures (40 days). The POD isozyme patterns showed almost the same regardless of cell growth stage, but some acidic isozymes were slightly increased after 25 days of subculture. These results indicate that POD activity in suspension cultures of sweet potato is closely associated with cell growth and stresses derived from cell culture renditions and medium depletion. Due to its high POD activity the SPL47cell line seems to be suitable for the mass production of POD.

• Food Science and Preservation
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• v.23 no.7
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• pp.913-922
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• 2016

The aim of this study was to develop a new salting condition that included added maltodextrin (MD) and grape seed extract (GSE) to ensure the microbiological safety and quality of salted shredded Korean cabbage. Response surface methodology (RSM) was used to analyze the effects of four independent variables (NaCl concentration, salting duration, MD concentration, and GSE concentration). The following response variables were evaluated: reduction in total aerobic bacteria, yeast, and mold counts; weight loss and salt content; and taste, texture, and overall acceptability of salted shredded Korean cabbage. The optimal salting conditions include a combination of 10.09~10.32% NaCl, 9.45~10.00% MD, and 234~300 ppm GSE in a ternary salting solution and a salting duration of 5.68~5.94 hr. This optimal combination reduced total aerobic bacterial and yeast/molds counts by 3.33 and 1.45 log CFU/g, respectively, while maintaining high sensory scores for taste, texture, and overall acceptability of the salted shredded Korean cabbage. In addition, the optimal conditions yielded more acceptable weight loss and salt content characteristics. The results suggest that use of the optimized combination of salting conditions can improve the microbiological safety and quality of salted shredded Korean cabbage used for commercial kimchi production.