• Journal of Animal Science and Technology
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• v.61 no.4
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• pp.185-191
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• 2019

The aim of this study was to evaluate different herbicides for optimum growth, yield and nutritive value of corn-soybean mixed forage under randomized complete block design. The experimental site was selected and divided equally into 3 blocks. Each block was further divided into 5 plots that each plot had 15 square meter space ($3{\times}5$). Five herbicidal treatments were randomly applied over 5 plots and herbicides were used under 5 herbicidal treatments, viz. 1) No herbicide (control); 2) Pendimethalin; 3) Linuron; 4) S-metolachlor and 5) Ethalfluralin. The collected data were analyzed using ANOVA through SAS 9.1.3 software. The results indicated that growth characteristics were not influenced (p > 0.05) by any herbicide. However, arithmetically corn stalk height was highest in the field of Pendimethalin treatment, whereas highest soybean height was found in the field of S-metolachlor. Arithmetically dry matter (DM) yield was increased with herbicidal treatments as compared to that of control treatment. Relatively highest DM yield (130%) was recorded in the treatment of Ethalfluralin followed by Pendimethalin (126%), S-metolachlor (126%) and Linuron (108%) as compared to that of control treatment. The weed emergence was significantly reduced in all herbicidal treatments as compared to that of control (p > 0.05), but the difference among herbicidal treatments was non-significant. It was concluded that weed emergence can be effectively controlled by use of any tested herbicide. However, optimum DM yield can be achieved through using herbicides; Ethalfluralin, Pendimethalin and S-metolachlor.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.1
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• pp.80-91
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• 2017

The objective of this study was to select a model showing high-levels of interpretability which is high in R-squared value in terms of predicting the yield in the mixed pasture using the factors of fertilization, seeding rate and years after pasture establishment in steps, as well as the climate as a basic factor. The processes of constructing the yield prediction model for the mixed pasture were performed in the sequence of data collection (forage and climatic data), preparation, analysis, and model construction. Through this process, six models were constructed after considering climatic variables, fertilization management, seeding rates, and periods after pasture establishment years in steps, thereafter the optimum model was selected through considering the coincidence of the models to the forage production theories. As a result, Model VI (R squared = 53.8%) including climatic variables, fertilization amount, seeding rates, and periods after pasture establishment was considered as the optimum yield prediction model for mixed pastures in South Korea. The interpretability of independent variables in the model were decreased in the sequence of climatic variables(24.5%), fertilization amount(17.8%), seeding rates(10.7%), and periods after pasture establishment(0.8%). However, it is necessary to investigate the reasons of positive correlation between dry matter yield and days of summer depression (DSD) by considering cultivated locations and using other cumulative temperature related variables instead of DSD. Meanwhile the another research about the optimum levels of fertilization amounts and seeding rates is required using the quadratic term due to the certain value-centered distribution of these two variables.

• KSBB Journal
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• v.15 no.6
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• pp.566-572
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• 2000

Experimental studies were carried out to develop an osmotolerant mutant of Candida magnoliae JH and to determine the optimum concentrations of carbon and nitrogen sources to improve erythritol yield and productivity. Mutants of C. magnoliae JH were prepared by treatment with ethylmethane sulfonate, and osmotolerant mutants were isolated from the agar plate colonies containing 2.5 M KCI. Among the mutants isolated, one mutant M26 was finally selected based on erythritol yield and productivity. In shake flask culture, glucose proved to be the best carbon source and the optimum yeast extract concentration was 5 g/L based on 100 g/L glucose. The erythritol yield and productivity of mutant M26 were greater than wild type in 100 g/L glucose medium. in the fermentation experiments, erythritol production increased with increased glucose concentration, up to a limit of 250 g/L. The maximum concentration of erythritol achieved 127.5 g/L, and the yield and productivity of erythritol production were 51.0% and 0.63 g/L-h, respectively.

• Korean Journal of Medicinal Crop Science
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• v.27 no.5
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• pp.322-329
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• 2019

Background: Studies have suggested that the northern provinces of Gangwon-do are good sites for licorice (Glycyrrhiza uralensis Fisch.) cultivation in Korea, as they have similar temperatures to its original locations in northern China. However, poor growth and freezing injury are often reported in Korea. Therefore, it is necessary to reassess the domestic cultivation site of licorice. Methods and Results: To determine the optimum temperature for cultivating licorice, the growth, yield, and pharmacological characteristics of G. uralensis were assessed in a temperature gradient tunnel at Eumseong, Chungcheongbuk-do, Korea in 2017. Plant height increased until the temperature rose to $5.9^{\circ}C$ above the local external temperature. Yield (㎏/10a) increased by 46.9% when the growing temperature was $1.5^{\circ}C$ to $3.0^{\circ}C$ (T2) above the external temperature and by 72.6% when the growing temperature was $3.0^{\circ}C-4.5^{\circ}C$ (T3) above the external temperature. However, a difference of $4.5^{\circ}C-5.9^{\circ}C$ (T4) above the external temperature, decreased the yield by 9.8% compared to that at T2. The glycyrrhizin content of G. uralensis roots in each temperature band was 0.72%, 0.53%, 0.91%, and 0.84% (T1, T2, T3, T4), these differences appear to result form individual plant variation rather than growth temperature. Conclusions: Based on the results of this study, we estimate that the temperature-based optimum cultivation site for G. uralensis in Korea is the south central region, rather than the northern province of Gangwon-do. Improvement in growth and yield maybe observed if the plantations in the central Jecheon (Chungcheongbuk-do, Korea) are expanded into the south central region.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2002.11b
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• pp.56-57
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• 2002

• Applied Biological Chemistry
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• v.48 no.1
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• pp.89-92
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• 2005

This study was conducted in order to establish the optimum extraction conditions in obtaining Saururus chinensis extracts. At the optimum extraction solvent (40% ethanol solvent), yield, DPPH, total phenolic compounds and total flavonoid in the extract of Saururus chinensis were 13.50%, 83.50%, 2.60 mg/ml and 2.09 mg/ml, respectively. At the optimum extraction time (4 hours), yield, DPPH, total phenolic compounds and total flavonoid in the extract of Saururus chinensis were 12.79%, 71.13%, 2.83 mg/ml and 2.16 mg/ml, respectively. At the optimum conditions (40% ethanol solvent and 4 hours), quercetrin and quercetin contents were 360.13 mg/100 g and 1379.54 mg/100 g, respectively. From the above results, we suggest that the optimum Saururus chinensis extract conditions are 40% ethanol solvent and 4 hours.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.2
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• pp.103-111
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• 1993

A greenhouse experiment was conducted to determine the number of optimum. tillers within a plant for high yield and to clarify the morpho-anatomical characteristics of cultivars having different tillering abilities. Optimum tillers, i.e tillers which produced heavy panicles were found to be around five to nine tillers per plant, although wider range may be possible if more cultivars were tested or under different growth conditions. Optimum tillers emerged within a short time after transplanting as compared with the other tillers. They exhibited longer tiller duration, produced more spikelets and had better filled spikelets, more vascular bundles and were taller with larger leaf area. However, the 1, 000 grain weight and fertility varied with cultivars and showed no general trend. Of this morpho-anatomical features, the total number of spike lets per plant was considered as the potential criterion for determining the optimum tiller number.

• The Korean Journal of Food And Nutrition
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• v.30 no.2
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• pp.319-325
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• 2017

In this study, we optimized the coffee extraction conditions for instant coffee production in two stage percolators, which is the most common coffee extractor for instant coffee production. A central composite design was used to build mathematical model equations for response surface methodology (RSM). In these equations, the yield and overall acceptability of the coffee extracts were expressed as second-order functions of three factors, the feed water temperature, draw-off factor (DOF), and extraction time (cycle time). Based on the result of RSM, the optimum conditions were obtained with the use of desirability function approach (DFA) which find the best compromise area among multiple options. The optimum extraction conditions to maximize the yield and overall acceptability over 40% of yield were found with $163^{\circ}C$ of feed water temperature, 4.3 of DOF and 27 minutes of extraction time (cycle time). These results provide a basic data for the coffee extraction conditions for the competitive instant coffee in the industry.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.6
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• pp.496-500
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• 1991

To obtain information on the forage yield and quality of barley, wheat and triticale, fresh and dry yields and chemical components of respective local varieties for each species were measured at heading stage, 7th day after heading (DAH), 14th DAH, 21st DAH and yellow ripe stage. Fresh yield of triticale was higher than those of barley and wheat at all stages. The time of optimum forage moisture for silage was 24-31 DAH in barley, 24-35DAH in wheat and 25-34 in triticale, The percentage content of protein and fat of barley were higher than those of wheat and triticale. Optimum cutting time for silage as proposed with the observa. tions that for barley and wheat it was at 23DAH, and for triticale at 24DAH. In relation to the optimum transplanting time of rice, barley was considered the most suitable species for whole crop silage in the central region of Korea.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.10a
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• pp.265-272
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• 2000

Unbond brace hysteretic dampers are generally used to prevent or decrease structural damage in buildings subjected to strong earthquake by its energy dissipating hysteretic behavior. According to a previous research, the optimum ratio of device yield strength to story yield strength of the combined system has been identified as the most important parameter for characterizing the performance of this device. In this research, the validity and the applicability of the previous research has been investigated and a new approach has been proposed through earthquake response analysis of a steel structure installed with unbond brace type hysteretic damper.