• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.391-393
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• 2004

For performance and stability of a synchronized system, we need an efficient Clock Tree Synthesis(CTS) methodology to design clock distribution networks. In a system-on-a-chip(SOC) design environment, CTS effectively distributes clock signals from clock sources to synchronized points on layout design. In this paper, we suggest the pre-layout analysis of the clock network including gated clock, multiple clock, and test mode CTS optimization. This analysis can help to avoid design failure with potential CTS problems from logic designers and supply layout constraints so as to get an optimal clock distribution network. Our new design flow including pre-layout CTS analysis and structural violation checking also contributes to reduce design time significantly.

• Journal of Microbiology and Biotechnology
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• 제28권4호
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• pp.566-570
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• 2018

Because glycosylation of aesculetin and its 6-glucoside, aesculin, enhances their biological activities and physicochemical properties, whole-cell biotransformation and enzymatic synthesis methodologies using Neisseria polysaccharea amylosucrase were compared to determine the optimal production method for glycoside derivatives. High-performance liquid chromatography analysis of reaction products revealed two glycosylated products (AGG1 and AGG2) when aesculin was used as an acceptor, and three products (AG1, AG2, and AG3) when using aesculetin. The whole-cell biotransformation production yields of the major transfer products for each acceptor (AGG1 and AG1) were 85% and 25%, respectively, compared with 68% and 14% for enzymatic synthesis. These results indicate that whole-cell biotransformation is more efficient than enzymatic synthesis for the production of glycoside derivatives.

• Journal of Multimedia Information System
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• 제2권3호
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• pp.263-274
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• 2015

The subject of this work is the complex discrete systems simulation special features with the aid of dynamic graph models. The proposed simulation technique allows to determine the ways for tasks solutions in terms of discrete systems analysis and synthesis of various complication: one-dimensional and multidimensional, steady and unstable, with the pulse elements abnormal operating mode and others. Often complex control systems analysis and synthesis task solutions, via classical approach comes out to be insolvent, because of the computational problems. The application of graph models allows to perform clear and strict characterization and computer procedures automation. The optimal controls synthesis algorithm presented in this paper, transferring the discrete system from target initial state to target final state within the minimum time, allows to consider the zero initial conditions systems, with the initial potential energy, with the control actions limitations and complex pulse elements operating mode.

• Korean Chemical Engineering Research
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• 제56권3호
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• pp.416-420
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• 2018

A comprehensive kinetic study has been conducted on dimethyl carbonate synthesis by transesterification reaction of ethylene carbonate with methanol. An alkali base metal (KOH) was used as catalyst in the synthesis of DMC, and its catalytic ability was investigated in terms of kinetics. The experiment was performed in a batch reactor at atmospheric pressure. The reaction orders, the activation energy and the rate constants were determined for both forward and backward reactions. The reaction order for forward and backward reactions was 0.87 and 2.15, and the activation energy was 12.73 and 29.28 kJ/mol, respectively. Using the general factor analysis in the design of experiments, we analyzed the main effects and interactions according to the MeOH/EC, reaction temperature and KOH concentration. DMC yield with various reaction conditions was presented for all ranges using surface and contour plot. Furthermore, the optimal conditions for DMC yield were determined using response surface method.

• International Journal of Control, Automation, and Systems
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• 제1권2호
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• pp.184-193
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• 2003

Biaffine Matrix Inequality (BMI) is known to provide the most general framework in control synthesis, but problems involving BMI's are very difficult to solve because nonconvex optimization should be solved. In the previous paper, we proposed a new solver for problems involving BMI's using Evolutionary Algorithms (EA). In this paper, we solve several control synthesis examples such as Reduced-order control, Simultaneous stabilization, Multi-objective control, $H_{\infty}$ optimal control, Maxed $H_2$ / $H_{\infty}$control design, and Robust $H_{\infty}$ control. Each of these problems is formulated as the standard BMI form, and solved by the proposed algorithm. The performance in each case is compared with those of conventional methods.

• 약학회지
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• 제45권1호
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• pp.23-28
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• 2001

Hydrotalcite was prepared by reacting with sodium carbonate, magnesium hydroxide and aluminum chloride solutions in this study. The optimum synthesis conditions based on the yield of the product were established by applying Box-Wilson experimental design. It was found that the optimum synthesis conditions of hydrotalcite were as follows ; reacting temperature : 63~9$0^{\circ}C$, concentration of reactant solution : 18.20~19.82%, molar concentration ratio of two reactants [Mg(OH)$_2$] / (AICl$_3$.6$H_2O$) : 6.0, temperature of washing water : 29.0-34.4$^{\circ}C$, drying temperature : 56-77.6$^{\circ}C$. The physicochemical properties of hydrotalcite as medicine were studied by use of chemical analysis, bulk volume test and acid consuming capacity measurements.

• 약학회지
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• 제43권6호
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• pp.689-695
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• 1999

Hydrotalcite was prepared by reacting with sodium carbonate, magnesium oxide and aluminum sulfate solutions in this study. The optimum synthesis conditions based on the yield of the product were established by applying Box-Wilson experimental design. It was found that the optimum synthesis conditions of hydrotalcite were as follows; reacting temperature : 48~63$^{\circ}C$, concentration of reactant solution : about 20%, molar concentration ratio of two reactants [MgO]/[Al. sulfate] ; 7.35~8.1, temperature of washing water : 34.4~37.4$^{\circ}C$, drying temperature : 74~81.5$^{\circ}C$. The physicochemical properties of hydrotalcite as medicine were studied by use of chemical analysis, D.S.C. thermogram, bulk volume test and acid consuming capacity measurements.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.109-110
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• 2007

Pyrrole and DNA can be used for synthesis of conducting nanowires. Protonated pyrrole and negatively charged DNA are absorbed by electrostatic interaction. The level of absorbance is related to pH of pyrrole. Therefore, DNA immobilized and aligned on the 3-aminopropyltrimethoxysi1ane (APTES) modified Si surface. Positive pyrrole monomers was deposited on aligned DNA for the synthesis of nanowire in various pH condition. And polypyrrole nanowires were synthesized by polimerization with ammonium persulfate (APS). These polypyrrole nanowires were measured by AFM, and then we found optimal pH level for the synthesis of nanowires.

• Bulletin of the Korean Chemical Society
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• 제4권2호
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• pp.72-76
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• 1983

Cephaloglycin was synthesized directly from D-${\alpha}$ -phenylglycine methyl ester and 7-aminocephalosporanic acid using whole cell enzyme of Xanthomonas citri (IFO 3835). Some optimal conditions for cephaloglycin synthesis were investigated, and yield improvements for its production by several methods were attempted. Using the whole cell enzyme system, the reaction kinetic model for cephaloglycin synthesis is proposed, and the kinetic constants for D-${\alpha}$ -phenylglycine methyl ester hydrolysis, cephaloglycin synthesis, and cephaloglycin hydrolysis were determined. The $K_m$ values of D-${\alpha}$-phenylglycine methyl ester, 7-aminocephalosporanic acid, and cephaloglycin were 11 mM, 24 mM, and 167 mM, and $K_i$ value of D-${\alpha}$-phenylglycine was 15 mM, respectively. The pattern of product inhibition was found to be competitive one.

• 한국통신학회:학술대회논문집
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• 한국통신학회 2004년도 하계종합학술발표회논문초록집
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• pp.324-324
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• 2004