• Environmental Engineering Research
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• v.22 no.1
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• pp.19-30
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• 2017

Direct catalysis of vapors from vacuum pyrolysis of biomass was performed on MCM-41 to investigate the effects of operating parameters including catalyzing temperature, catalyzing bed height and system pressure on the organic yields. Optimization of organic phase yield was further conducted by employing response surface methodology. The statistical analysis showed that operating parameters have significant effects on the organic phase yield. The organic phase yield first increases and then decreases as catalyzing temperature and catalyzing bed height increase, and decreases as system pressure increases. The optimal conditions for the maximum organic phase yield were obtained at catalyzing temperature of $502.7^{\circ}C$, catalyzing bed height of 2.74 cm and system pressure of 6.83 kPa, the organic phase yield amounts to 15.84% which is quite close to the predicted value 16.19%. The H/C, O/C molar ratios (dry basis), density, pH value, kinematic viscosity and high heat value of the organic phase obtained at optimal conditions were 1.287, 0.174, $0.98g/cm^3$, 5.12, $5.87mm^2/s$ and 33.08 MJ/kg, respectively. Organic product compositions were examined using gas chromatography/mass spectrometry and the analysis showed that the content of oxygenated aromatics in organic phase had decreased and hydrocarbons had increased, and the hydrocarbons in organic phase were mainly aliphatic hydrocarbons. Besides, thermo-gravimetric analysis of the MCM-41 zeolite was conducted within air atmosphere and the results showed that when the catalyst continuously works over 100 min, the index of physicochemical properties of bio-oil decreases gradually from 1.15 to 0.45, suggesting that the refined bio-oil significantly deteriorates. Meanwhile, the coke deposition of catalyst increases from 4.97% to 14.81%, which suggests that the catalytic activity significantly decreases till the catalyst completely looses its activity.

• Journal of Life Science
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• v.13 no.6
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• pp.794-798
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• 2003

Batch production of (S)-phenyl oxirane was investigated using epoxide hydrolase activity of Rhodosporidium toruloides SJ-4. Effect of reaction condition of asymmetric biohydrolysis of racemic phenyl oxirane was analyzed and optimized by response surface methodology. The optimal conditions of pH, temperature and DMSO cosolvent ratio were 7.4, $34^P\circ}C$, and 2.3%(v/v), respectively. The final yield was enhanced up to 67%, and reaction times required to reach 99% ee (enatiomeric excess) decreased down to 50% by response surface methodology Enantiopure (S)-phenyl oxirane with 100% enantiopurity and 24% yield (theoretical yield = 50%) was obtained from racemic substrate.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.63-63
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• 2022

Wheat flour can be categorized into bread, all-purpose, cake flour according to its protein content. Since optimal wheat flour protein content is different for each end use, it is necessary to diversify the nitrogen fertilizer methods depending on the end use and cultivar. Optimal wheat flour protein content of soft wheat (for cake flour) is lowest (<=10%) among all end use, it is necessary to develop nitrogen fertilizer methods for high yield and low protein content. In order to analyze the yield and quality changes of soft wheat as nitrogen fertilizer amount and splitting timing, soft wheat cultivar 'goso' was sown on paddy soil in jeunju, Republic of Korea ('21.10). the amount of nitrogen fertilizer was divided into 4 levels by adjusting 2kg/10a increments from 5.1 to ll.lkg/lOa, and in the N 7.1 and 9.1 kg/1 Oa(standard) treatment, N amount divided into sowing date:regrowing stage=3:7,4:6(standard), 5:5. In regrowing stage, Tiller number and N fertilizer amount at sowing date showed a correlation; y=-121.14x²+792.66x-525.41 (R²=0.77^*, y: Tiller number/m², x: N amount at sowing date(kg/10a)). Tiller number in regrowing stage was the highest when the nitrogen fertilizer amount at sowing date was 3.23kg/10a. spike number per m² was the highest when N fertilizer was divided into sowing date:regrowing stage=3:7(N amount: 9.1kg/10a). If N fertilizer amount was fixed, grain yield was also the highest when N fertilizer was divided into sowing date :regrowing stage=3:7. Also, N amount at sowing date and grain yield showed no correlation, but N amount at regrowing stage and grain yield showed significant correlation. As N amount increased, protein content also showed a tendency to increase.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2093-2098
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• 2005

In this paper, $H_{2}$ designs for the one-degree-of-freedom decoupling control systems are treated for the generalized plant. The optimal $H_{2}$ controller is obtained together with the ones that yield finite $H_{2}$ cost functions under compact assumptions. It is shown that the optimal closed transfer matrix is strictly proper under the reasonable order assumptions on the generalized plant.

• Journal of Korean Society for Quality Management
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• v.34 no.1
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• pp.48-53
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• 2006

Applying Bayesian optimal design principles is not easy when a prior distribution is not certain. We present a optimal design criterion which possibly yield a reasonably good design and also robust with respect to misspecification of the prior distributions. The criterion is applied to the problem of estimating the turning point of a quadratic regression. Exact mathematical results are presented under certain conditions on prior distributions. Computational results are given for some cases not satisfying our conditions.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.49
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• pp.33-41
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• 1999

The original tolerances, which are assigned by designers on the basis of handbooks and experience, cannot always be expected to be optimal or feasible, because they may yield an unacceptable manufacturing costs. So the systematic tolerance design considering manufacturing costs should be done. Therefore, this research analyzes the tolerance within the tolerance design using Monte-Carlo simulation method and sensitivity analysis and using genetic algorithm by tolerance allocation method. The genetic algorithm was developed for allocation of the optimal tolerance under the manufacturing limitation cost.

• Journal of The Korean Society of Grassland and Forage Science
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• v.9 no.2
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• pp.108-112
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• 1989

To determine optimal plant density of forage rape in southern areas of Korea, Velox, the highest yielding variety among seventeen introduced varieties of forage rape, was grown under five different plant densities. The results obtained are summarized as follows: 1. Yield components such as stem diameter, number of main stem,leaves, number of branches and number of branch leaves and fresh yield were highest at the plots with 50cm row spacing and 30cm plant spacing. 2. Dry matter yield, content of crude protein, IVDMD and digestible dry matter yield were highest at the plots of broadcasting. 3. Since plants under high density were high in plant length and small in stem diameter, contents of crude fiber such as NDF, ADF, cellulose and lignin were lowest at the plots of broadcasting.

• Journal of the Korean Chemical Society
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• v.56 no.5
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• pp.603-608
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• 2012

3-(Perfluorooctyl)propan-2-ol was synthesized using an alcoholization process. The synthesis consisted of two steps: (1) addition of the olefin propylene to perfluorooctyl iodide to yield the corresponding iodo-adduct perfluorooctyl propyl iodide and (2) hydrolysis of the adduct reacted with water and dimethylformamide to yield the final product. The adduct and product were analyzed using gas chromatography to determine the yield and purity. The optimal conditions for each step of the process were determined, and a 93% yield of adduct and 95% yield of final product was achieved.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1145-1149
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• 1990

This paper proposes a numerical method for redundant manipulators using predetermined optimal resolution. In order to obtain optimal joint trajectories, it is desirable to formulate redundancy resolution as an optimization problem having an integral cost criterion. We predetermine the trajectories of redundant joints in terms of the Nth partial sum of the Fourier series, which lead to the solution in the desirable homotopy class. Then optimal coefficients of the Fourier series, which yield the optimal solution within the predetermined class, are searched by the Powell's method. The proposed method is applied to a 3-link planar manipulator for cyclic tasks in Cartesian space. As the results, we can obtain the optimal solution in the desirable homotopy class without topological liftings of the solution. To show the validity of the proposed method, we analyze both optimal and extremal solutions by the Fast Fourier Transform (FFT) and discuss joint trajectories on the phase plane.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.354-354
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• 2017

Rice grain yield is determined by crop dry matter production that is sensitive to temperature. Our objective was to determine whether the difference in temperature between years had an impact on the relationship between yield components and grain yield. Field experiments were conducted under machine transplanting cultivation by using yield data of two japonica rice varieties, Odaebyeo (early maturing) and Nampyeong (mid-late maturing), in 2013 to 2016 in Suwon, Korea. Plant height, dry weight, and yield components were examined by analysis of variance, correlation. The milled rice yield of the two varieties were the highest in 2016, however the lowest yields were observed in the different years. In 2016, Odaebyeo produced $0.96t\;ha^{-1}$ greater milled rice yield than in 2015, and Nampyeong produced $1.11t\;ha^{-1}$ greater yield than in 2013. The correlation analysis indicated that spikelet per panicle (R = 0.53) was associated with grain yield of Odaebyeo. In Nampyeong, biomass at heading date (R = 0.74), 1000-grain weight (R = 0.71), spikelet per panicle (R = 0.58), and panicle number per $m^2$ were associated with grain yield. Sink size (spikelet number per $m^2$) of the two varieties responded to accumulative temperature from transplanting to panicle initiation stage. In this experiment, optimal accumulative temperature before panicle initiation has effect on increased spikelet number and/or number of panicle that were mainly responsible for yield difference. Rice production research to increase grain yield should consider all yield components, but increased emphasis on biomass production before heading is also necessary as well as grain ripening conditions.