• Journal of the Korean Chemical Society
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• v.9 no.1
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• pp.49-54
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• 1965

One of the difficult and time consuming problems in the production of magnesia from sea water is a settling rate of magnesium hydroxide. In this experiments, authors attempted to accelerate its settling rate by addition of various sedimenting agents as C.M.C., Separan and Starch, and sought for optimum calcination temperature for domestic dolomite, as alkali source, mole ratio of dolomite milk to bittern. It is observed through experiments that the small amounts of sedimenting agents, C.M.C., Separan, starch, 20 mg/l, 40 mg/l, 400mg/l, respectively increase the settling rate of magnesium hydroxide by 8 times or more. The following conditions resulted in good yield of magnesium hydroxide from sea water with relatively tolerable calcium oxide contaminated for the magnesium clinker. Calcinating temperature, $1,100{\sim}1,200^{\circ}C$, mole ratio of 10% dolomite milk to magnesium salts in sea water or bittern, 1. 2 : 1.

• Journal of the Korean Operations Research and Management Science Society
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• v.28 no.2
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• pp.1-15
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• 2003

This paper presents a new evolutionary algorithm to solve complex multi-level integration problems, which is called multi-level symbiotic evolutionary algorithm (MEA). The MEA uses an efficient feedback mechanism to flow evolution information between and within levels, to enhance parallel search capability, and to improve convergence speed and population diversity. To show the MEA's applicability, It is applied to the integrated planning of production and distribution in supply chain management. The encoding and decoding methods are devised for the integrated problem. A set of experiments has been carried out, and the results are reported. The superiority of the algorithm's performance is demonstrated through experiments.

• Journal of Microbiology
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• v.43 no.1
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• pp.38-43
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• 2005

Lactic acid production parameter optimization using Lactobacillus amylovorus NRRL B-4542 was performed using the design of experiments (DOE) available in the form of an orthogonal array and a software for automatic design and analysis of the experiments, both based on Taguchi protocol. Optimal levels of physical parameters and key media components namely temperature, pH, inoculum size, moisture, yeast extract, $MgSO_4{\cdot}7H_20$, Tween 80, and corn steep liquor (CSL) were determined. Among the physical parameters, temperature contributed higher influence, and among media components, yeast extract, $MgSO_4{\cdot}7H_20$, and Tween 80 played important roles in the conversion of starch to lactic acid. The expected yield of lactic acid under these optimal conditions was 95.80% and the actual yield at optimum conditions was 93.50%.

• International journal of advanced smart convergence
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• v.9 no.2
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• pp.179-184
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• 2020

Recently, webtoons-based animations have been expanding in Korea, where the role of mobile devices is growing, and media videos such as "YouTube" and "Tik-Tok," which have shorter screening and production cycles than traditional feature films, dramas, and animations, are attracting attention and being enjoyed by public. In order to produce animation content that fits the trend of this shortening video and production cycle, efficiency must be increased not only in story but also in production. Production methods and production technologies need changes to increase efficiency. Animation using motion capture, which is highly production-efficient, is widely used in movies that shows realistic movements, but still has little use in producing cartoon-style animations with exaggerated movements. We analyzed the production method of 2D animation and CG animation and applied the result to CG animation to increase the efficiency of production and production. The methods of production through such experiments are expected to help improve the efficiency of producing animation content that is suitable for the latest trends such as webtoon animation.

• MALSORI
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• no.52
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• pp.61-84
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• 2004

This study investigates the Korean native speakers' English liquid perception and production. Perception and production experiments were each conducted twice before and after a short period of explicit learning process of phonetic characteristics of English liquids. The results showed that correlation between perception and production varied depending on factors. In both perception and production, word-final position was the most difficult, and cluster position was the easiest. A considerable improvement was observed in word-initial and medial positions in production, whereas no improvement was achieved in word-final position, especially in production. This study is also concerned with the formant structures of Korean native speakers' production of English liquids in order to see what acoustic features are highly correlated with Korean native speakers' production accuracy of English liquids. The results showed that F2 did not show a high correlation while F3 was a strong correlate of the production accuracy.

• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3768-3774
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• 2023

The purpose of the target system for the muon spin rotation, relaxation, and resonance (µSR) facility at the Rare isotope Accelerator complex for ON-line experiments (RAON) is to induce the production of a significant number of surface muons in thermally stable experiments. The manufactured target system was installed at RAON in the Sindong area near Daejeon in 2021. The design was made conservatively with a sufficient margin of safety through ANSYS calculations; however, verification experiments had to be performed on the ANSYS calculations. Because the 600-MeV proton beam has not yet been provided, an alternative way to reproduce the calculation conditions was required. The radio frequency (RF) heating method, which has not yet been applied to the target verification experiment but has several advantages, was used. It was observed that the RF heating method has promise for testing the thermal stability of the target, and whether the target system design process was performed conservatively enough was verified by comparing the RF heating experiments with the ANSYS calculations.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.351-355
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• 2003

Response surface methodology was employed to study the interactive effect of sucrose, nitrogen, temperature and to optimize their levels to enhance the production of human granulocyte-macrophage colony-stimulation factor from Nicotiana tabacum cell suspension cultures. A 15-runs Box-Behnken design including three center points was the response surface method selected for the initial set of experiments. The analysis of the data from the Box-Behnken experiments showed interactive effects of sucrose:nitrogen, sucrose:temperature and nitrogen:temperature. The optimal combinations of sucrose, nitrogen and temperature for hGM-CSF production from surface plot were sucrose 90 g/L, nitrogen 41 mM and 22$^{\circ}C$, respectively. The optimization of there factors enhanced the hGM-CSF production by 2 times because high sucrose concentration stimulated the secretion of hGM-CSF and low temperature prevented hGM-CSF degradation in media by pretenses.

• Structural Engineering and Mechanics
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• v.73 no.5
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• pp.501-513
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• 2020

In the present work, the optimization of machining parameters to achieve the desired technological parameters such as surface roughness, tool radial vibration and material removal rate have been carried out using response surface methodology (RSM). The hard turning of EN19 alloy steel with coated carbide (GC3015) cutting tools was studied. The main problem faced in manufacturer of hard and high precision components is the selection of optimum combination of cutting parameters for achieving required quality of surface finish with maximum production rate. This problem can be solved by development of mathematical model and execution of experiments by RSM. A face centred central composite design (FCCD), which comes under the RSM approach, with cutting parameters (cutting speed, feed rate and depth of cut) was used for statistical analysis. A second-order regression model were developed to correlate the cutting parameters with surface roughness, tool vibration and material removal rate. Consequently, numerical and graphical optimization were performed to obtain the most appropriate cutting parameters to produce the lowest surface roughness with minimal tool vibration and maximum material removal rate using desirability function approach. Finally, confirmation experiments were performed to verify the pertinence of the developed mathematical models.

• New & Renewable Energy
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• v.17 no.3
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• pp.8-15
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• 2021

In this study, we assessed the effect of vitamin components (such as biotin, thiamine-HCl, and folic acid) on microorganism microbial growth and ethanol production was examined to enhance increase the ethanol concentration in the Clostridium autoethanogenum culture process using syngas as a sole carbon source. Biotin and folic acid concentrations of 0.2, 2, 20, and 100 ㎍/L were used in the culture experiments at 0.2, 2, 20, and 100 ㎍/L concentrations. The maximum ethanol concentrations of 2.81 g/L and 3.12 g/L were obtained by adding at 0.2 ㎍/L biotin and folic acid, respectively. Moreover, Thiaminethiamine--HCl at concentrations of 0.5, 5, 50, and 250 ㎍/L were was examined evaluated to in the culture experiments. The maximum ethanol concentration of 2.84 g/L was observed at 0.5 ㎍/L of thiamine--HCl. As a resultThus, the optimized concentrations of biotin, thiamine--HCl, and folic acid were determined at 0.2, 0.5, and 0.2 ㎍/L, respectively, for enhancing increasing the ethanol production. In conclusion, the maximum ethanol production was obtained by adding the minimal concentration of vitamins in C. autoethanogenum culture.

• Journal of Plant Biotechnology
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• v.5 no.1
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• pp.1-6
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• 2003

The adventitious root of Panax ginseng C.A. Meyer is regarded as an efficient alternative to cell culture or hairy root culture for biomass production due to its fast growth and stable metabolite production. To determine optimal culture conditions for the bioreactor culture of ginseng roots, experiments have been conducted on physical and chemical factors such as bioreactor type, dissolved oxygen, gas supply, aeration, medium type, macro- and micro-elements, medium supplement during culture period, sucrose concentration, osmotic agents, medium pH and light. Elicitation is a key step to increase ginsenoside accumulation in the adventitious roots but biomass growth is severely inhibited by elicitor treatment. To obtain high ginsenoside content with avoiding biomass decrease, we applied two-stage bioreactor culture system. Ginseng adventitious roots were cultured for 40 days to maximize biomass increase followed by elicitation for 7 days to enhance ginsenoside accumulation. We also experimented on types and concentrations of jasmonate to determine optimal elicitation methods. In this paper, we discussed several factors affecting the root propagation and ginsenoside accumulation. Based on the results obtained from previous experiments we have established large-scale bioreactor system (1 ton-10 ton) for the efficient production of ginseng adventitious roots and bioactive compounds including ginsenoside. Still, experiments are on going in our laboratory to determine other bioactive compounds having effects on diet, high blood pressure, DPPH elimination and increasing memories.