• Journal of Microbiology and Biotechnology
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• v.17 no.7
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• pp.1221-1225
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• 2007

A ${\beta}$-ionone-resistant mutant strain isolated from the red yeast Xanthophyllomyces dendrorhous KCTC 7704 was used for batch and continuous fermentation kinetic studies with glucose media in a 2.5-1 jar fermentor at $22^{\circ}C$ and pH 4.5. The kinetic pattern of growth and carotenoid concentration in the batch fermentations exhibited a so-called mixed-growth-associated product formation, possibly due to the fact that the content of intracellular carotenoids depends on the degree of physical maturation toward adulthood. To determine the maximum specific growth rate constant (${\mu}_m$) and Monod constant ($K_s$) for the mutant, glucose-limited continuous culture studies were performed at different dilution rates within a range of $0.02-0.10\;h^{-1}$. A reciprocal plot of the steady-state data (viz., reciprocal of glucose concentration versus residence time) obtained from continuous culture experiments was used to estimate a ${\mu}_m$ of $0.15\;h^{-1}$ and $k_s$ of 1.19 g/l. The carotenoid content related to the residence time appeared to assume a typical form of saturation kinetics. The maximum carotenoid content ($X_m$) for the mutant was estimated to be $1.04\;{\mu}g/mg$ dry cell weight, and the Lee constant ($k_m$), which was tentatively defined in this work, was found to be 3.0 h.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.26 no.4
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• pp.387-394
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• 2017

This paper develops a pump system for patient with chronic pain or cancer. The pump module is consists of two micro-valve and membrane. The micro-valve is operated by a solenoid. With two solenoid valves which are connected via a drug transport line, the inlet and outlet are completely blocked. A silicon rubber membrane located between the two valves makes the flow-rate constant without any backflow. This pump module can control the flow-rate of drugs by controlling the time that the valves are opened and closed. The reservoir consists of a drug chamber and a gas chamber. As the gas chamber encloses the drug chamber, propellant gas which is injected into the gas chamber pressurizes the drug chamber regardless of volume of the drug chamber. To design the pump module, analysis a constant efficiency test, and accuracy test for the pump module were conducted.

• Journal of Communications and Networks
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• v.12 no.5
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• pp.459-465
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• 2010

A new blind equalization algorithm that is based on maximizing the probability that the constant modulus errors concentrate near zero is proposed. The cost function of the proposed algorithm is to maximize the probability that the equalizer output power is equal to the constant modulus of the transmitted symbols. Two blind information-theoretic learning (ITL) algorithms based on constant modulus error signals are also introduced: One for minimizing the Euclidean probability density function distance and the other for minimizing the constant modulus error entropy. The relations between the algorithms and their characteristics are investigated, and their performance is compared and analyzed through simulations in multi-path channel environments. The proposed algorithm has a lower computational complexity and a faster convergence speed than the other ITL algorithms that are based on a constant modulus error. The error samples of the proposed blind algorithm exhibit more concentrated density functions and superior error rate performance in severe multi-path channel environments when compared with the other algorithms.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.3
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• pp.93-102
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• 2008

In this paper, we propose a rate control algorithm for constant quality real time video coding. To achieve constant quality, previous algorithm exploit mean absolute of difference(MAD) as measure of frame complexity. However, if scene is abruptly changed or if quantization parameter is not constant, encoder produces various output bits with same MAD. Therefore we know that MAD does not appropriately reflect characteristic of frame. To solve this problem, we exploit model parameter as measure of frame complexity. Because model parameter means slope between output bits and MAD, it reflects correctly complexity of frame. And because previous model, R-MAD model, is not considered quantization parameter, as quantization parameter increases or decreases, model parameter of frame also vary. So model parameter obtained using previous model cannot reflect internal characteristic of video. We solve this problem using proposed model, which is considered quantization parameter. Experiment results show that our algorithm provide better performance, in terms of quality smoothness than previous algorithm. Especially, when scene is abruptly changed, our algorithm alleviates quality drop.

• Journal of ILASS-Korea
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• v.1 no.3
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• pp.29-36
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• 1996

The present study systematically investigates the effect of evaporation rate on the combustion characteristics and the flame stabilization in a gasoline engine. A constant volume combustion chamber was used to elucidate a basic combustion characteristics and the premixer was installed to control temperature and equivalence ratio. And the maximum pressure, combustion duration and flame propagation according to the evaporation rate were measured to determine the optimal temperature range for evaparating a gasoline fuel. These experimental results indicate that the combustion characteristics such as combustion chamber pressure and combustion duration were deteriorated by decreasing surrounding temperature of fuel injected. It was also found that the overall gasification process for gasoline fuel was strongly influenced by a combustion chamber temperature rather than a premixer temperature.

• Bulletin of the Korean Chemical Society
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• v.34 no.4
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• pp.1145-1152
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• 2013

The rate constant of alkaline fading of methyl green ($ME^{2+}$) was measured in the presence of non ionic (TX-100), cationic (DTAB) and anionic (SDS) surfactants. $ME^{2+}$ hydrolyses and fades in neutral water and in this work we search the effects of surfactants on its fading rate. The rate of reaction showed remarkable dependence on the electrical charge of the used surfactants. It was observed that the reaction rate constant decreased in the presence of DTAB and SDS and increased in the presence of TX-100. Binding constants of $ME^{2+}$ to TX-100, DTAB and SDS and the related thermodynamic parameters were obtained by classical (or stoichiometric) model. The results show that binding of $ME^{2+}$ to TX-100 and DTAB are two-region and that of SDS is three-region. Also, the binding constants of $ME^{2+}$ to surfactant molecules in DTAB/TX-100 and SDS/TX-100 mixed solutions and their stoichiometric ratios were obtained.

• Journal of Environmental Impact Assessment
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• v.14 no.1
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• pp.17-24
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• 2005

This study was performed to evaluate the adsorption rate of phosphate corrosion inhibitor and reaction rate constant in drinking water distribution systems. The optimum concentration of corrosion inhibitor would vary depending on the quality of water, pipe materials, and condition of metal surfaces. The current adsorption study indicated that the residual phosphate concentration of the corrosion inhibitor decreased with the time as it adsorbed on the surface of pipe material. As time went by, the residual phosphate concentration became constant. It means that the formation of the corrosion protection film on metal surfaces is completed.

• Textile Coloration and Finishing
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• v.17 no.4 s.83
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• pp.1-6
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• 2005

We studied the degree of variety of indigo for the electrochemical redox reaction in addition of reducing agent and the electrokinetic parameters. The electrokinetic parameters such asthe number of electron and the exchange rate constant were obtained by cyclic voltammetry. With increasing scan rate, the reduction currents of indigo were increased and the reduction potentials were shifted to the negative direction. As the results, the reduction processes of the indigo were proceeding to totally irreversible and diffusion controlled reaction. Also, exchange rate constant ($k^0$) and diffusion coefficient ($D_0$) of indigo were decreased by increasing concentration of reducing agent. We found that the less concentration, the more easily diffused and electron transferred and the product was more stable.

• Elastomers and Composites
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• v.28 no.3
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• pp.183-190
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• 1993

The radical copolymerization with propagation and depropagation is presented in order to estimate reactivity rate of monomers and $K_{11}$(the equilibrium constant for propagation and depropagation) in the copolymerization of ${\alpha}-methylstyrene-co-methylmethacrylate$ and ${\alpha}-methylstyrene-acrylonitrile$. The value of ${\alpha}-methylstyrene$ and methylmethacrylate and $K_{11}$ are found to be 0.48, 0.47 and 5.0 respectively. The value of ${\alpha}-methylstyrene$ and acrylonitrile and the $K_{11}$ are found to be 0.1251, 0.0577 and 23.8 respectively. The treatment rate constant of ${\alpha}-methylstyrene-co-methylmethacrylate$ and ${\alpha}-methylstyrene-co-acrylonitrile$ in the copolymerization is estimated to be 2.5, 80.72 regardless of monomer feed composition.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.5A
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• pp.279-289
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• 2012

Characteristics, such as the support limit and distortions, of minimum mean-squared error (MSE) N-level uniform and nonuniform scalar quantizers are studied for the family of the generalized gamma density functions as N increases. For the study, MSE-optimal scalar quantizers are designed at integer rates from 1 to 16 bits/sample, and their characteristics are compared with corresponding asymptotic formulas. The results show that the support limit formulas are generally accurate. They also show that the distortion of nonuniform quantizers is observed to converge to the Panter-Dite asymptotic constant, whereas the distortion of uniform quantizers exhibits slow or even stagnant convergence to its corresponding Hui-Neuhoff asymptotic constant at the studied rate range, though it may stay at a close proximity to the asymptotic constant for the Rayleigh and Laplacian pdfs. Additional terms in the asymptote result in quite considerable accuracy improvement, making the formulas useful especially when rate is 8 or greater.