• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.4
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• pp.225-230
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• 2002

Experiments on deactivation kinetics of immobilized lipase enzyme from Candida cyl-indracea were performed in stirred bath reactor using rice bran oil as the substrate and temperature as the deactivation parameter. The data were fitted In first order deactivation model. The effect of temperature on deactivation rate was represented by Arrhenius equation. Theoretical equations were developed based on pseudo-steady state approximation and Michaelis -Menten rate expression to predict the time course of conversion due to enzyme deactivation and apparent half-life of the immobilized enzyme activity in PFR and CSTH under constant feed rate polity for no diffusion limitation and diffusion limitation of first order. Stability of enzyme in these continuous reactors was predicted and factors affecting the stability were analyzed.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.658_659
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• 2009

This paper deals with the numerical implementation of the material sensitivity analysis, which is used to efficiently determine an optimal electric current distribution on a ship hull by corrosion of ship. A material sensitivity formula for the forward problem formulated in terms of the equivalent current method is analytically derived. Then, the components of the adjoint system including the electric pseudo-source are thoroughly investigated in order to obtain the first-order gradient information of an objective function with respect to the electric current. The purposed method has been successfully applied to a model ship and the predicted result on the underwater electric field due to corrosion of ship have been compared to that computed by FNREMUS software.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.3
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• pp.54-59
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• 2005

The cylindrical object are widely used as mechanical parts in the manufacturing process. In order to handling those objects using a robot or an automated machine automatically, the pose of the object must be known. The pose can be described by two rotation angles; one angle about the x axis and the other about the y axis. In the many previous researches these angles were obtained by the computationally intensive algorithm, that is, fitting the data as a polynomial and doing pseudo inverse. So that, this method required high performance microprocessor. In this paper in order to avoid complex computation, a new method based on a genetic algorithm is proposed and analyzed through a series of simulations. This algorithm utilized the geometry of the cylindrical shape. The simulation results show that this method find the pose angles very well In most cases, but the computation time is randomly changed because the genetic algorithm is basically one of the random search method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.11a
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• pp.320-323
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• 1995

In this paper, in order to improve withstand voltage properties of epoxy resin, IPN(interpenetrating polymer network) method was introduced and the influence was investigated. The sing1e network structure specimen(E series), simultaneous interpenetrating polymer network specimen(EMF series) and pseudo interpenetrating polymer network(EMP series) specimen were manufactured. In order to understand the internal structure properties, scanning electron microscopy method was utilized, rind glass transition temperature was measured. Also, AC voltage dielectric strength, tensile strength and impact strength were measured to investigate influence upon electrical and mechanical properties. As a result, it was confirmed that simultaneous interpenetrating polymer network specimen was the most execellent.

• Journal of Wetlands Research
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• v.9 no.1
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• pp.99-105
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• 2007

Nonylphenol polyetoxylates (NPnEOs) metabolites; nonylphenol (NP), nonylphenol monoethoxylate (NP1EO), nonylphenoxyacetic acid (NPEC) (collectively referred to "NPE-c") were examined for their degradations by using of lab-scale UV/photocatalytic silicagel (ultraviolet photocatalytic degradation in the presence of silicagel coated with titanium dioxide as a catalyst) reactor. NPE-c degradations by UV/photocatalytic silicagel treatment reached approximately 85-93 % after 40 min irradiation independently of its initial concentration (between ca. 0.5 and 2.0mg/l). Any intermediates under the NPE-c degradation were not identified by GC/MS sample analysis. Degradations of NPE-c were followed pseudo first-order kinetics. Then, the effectiveness of UV/photocatalytic silicagel treatment for degradation of NPE-c was in the order of NPEC > NP > NP1EO.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.70-72
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• 2009

In this paper, nonlinear active noise control(ANC) of a 3rd-order Volterra system, which is robust to background noise variation, is proposed along with a variable step-size Gauss-Seidel pseudo affine projection(VSSGS-PAP) algorithm. Simulation results demonstrate that the proposed approach yields better nonlinear ANC performance in a background noise variation environment, compared with the conventional methods for the nonlinear ANC.

• Journal of Environmental Science International
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• v.12 no.3
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• pp.319-324
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• 2003

The characteristics of photocatalytic decomposition of dye waste water by titanium dioxide was studied in a batch reactor under constant strength of ultra-violet ray. The decomposition rate of methyl orange by TiO$_2$ was pseudo-first order, anatase type TiO$_2$ was more effective than rutile type below the dosage of 5g. The decomposition rate was increased with decreasing initial pH, increasing reaction temperature and oxidant concentration. The decomposition rate of water soluble dyes was decreased in order of rhodamine B>eosin Y>methyl orange.

• Journal of The Korean Astronomical Society
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• v.29 no.2
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• pp.157-170
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• 1996

In order to determine the metallicity of a globuar cluster, M3,by using the spectral indices, a kind of index grid has been establshed by stars in globular clusters, M3, M15, M71 and old open cluster, NGC 188. The indices were measured from the medium resolution spectra of about $2{\AA}$. The summed indices were used to determine metallicity in order to increase signals. It is found that the core depth index is measured more accurately and leads result more accurate than the pseudo-equivalent width index. This method can be further improved by including many more calibration globular clusters of various metallicity to make finer grids. By this method, the metallicity of M3 is determined as $[Fe/H] = -1.46\pm0.15$.

• Proceedings of the KIEE Conference
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• 1997.07e
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• pp.1767-1769
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• 1997

In this paper, interpenetrating polymer network method was introduced in order to improve withstand voltage properties of epoxy resin. The single network structure specimen(E series), simultaneous interpenetrating polymer network specimen(EM series) and pseudo interpenetrating polymer network(EMP series) specimen were manufactured. In order to investigate influence upon electrical properties, dc, ac, and impulse voltage dielectric strength were measured. As a result, it was confirmed that electrical properties of epoxy composites can be superior as IPN introduced to it bring about firm and high density of inner structure.

• Bulletin of the Korean Chemical Society
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• v.23 no.7
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• pp.990-994
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• 2002

Hydroxybenzothiophenes, dihydroxy-benzothiophenes, and benzothiophenedione were identified as inter-mediates of benzothiophene (BT) exposed to ultrasonic irradiation. It is proposed that benzothiophene is oxidized by OH radical to sequentially for m hydroxybenzothiophenes, dihydroxybenzothiophenes, and benzothiophenedione. Benzothiophene is decomposed rapidly following pseudo-first-order kinetics in a first-order manner by ultrasonic irradiation in aqueous solution. The toxicity of sonochemically treated solutions was checked by E. coli and a less inhibition in bacterial respiration was observed from the 120-min treated benzothiophene sample than from the untreated benzothiophene sample. Also evolution of carbon dioxide and sulfite was observed during ultrasonic reaction. A pathway for ultrasonic decomposition of benzothiophene in aqueous solution is proposed.