• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.197-200
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• 2001

Novel Enhanced Inductively Coupled Plasma is applied to etch $SiO_2$. Effect of $O_2$ or Ar addition to $C_{4}F_{8}$ gas is monitored by Optical Emission Spectroscopy and Quadrupole Mass Spectrometer. It is fund that Ar or $O_2$ dilution to $C_{4}F_{8}$ increases F emission intensity and decreases $CF_2$ intensity. However, the ac frequency to the Helmholtz coil decreases the F intensity and thus increases $CF_2$/F ratio. By adjusting the ac frequency, the optimum etch rate and PR to $SiO_2$ selectivity can be obtained in E-lCP.

• Journal of Power Electronics
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• v.12 no.3
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• pp.509-517
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• 2012

This paper presents control strategies for cascaded H-bridge multilevel active power filters (APFs). A current loop controller is implemented using a proportional-resonant (PR) regulator, which achieves zero steady-state error at target frequencies. The power balancing mechanism for the dc-link capacitor voltages is analyzed and a voltage balancing controller is presented. To mitigate the picket-fence effect of the conventional FFT algorithm under asynchronous sampling conditions, the Hanning Windowed-FFT algorithm is proposed for reference current generation (RCG). This calculates the frequency, amplitude and phase of individual harmonic components accurately and as a result, selective harmonic compensation (SHC) is achieved. Simulation and experimental results are presented, which verify the validity and effectiveness of the devised control algorithms.

• Journal of Power System Engineering
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• v.11 no.4
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• pp.56-64
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• 2007

A numerical simulation is carried out mixed convection in horizontal channel with a heat source from below of rectangular cavity. Finite volume method was employed for the discretization and PISO algorithm was used for calculating pressure term. The parameters governing the problem are the Reynolds number ($10^{-2}{\leq}Re{\leq}50$), the Rayleigh number ($10^3{\leq}Ra{\leq}2.06{\times}10^5$), the Prandtl number ($0.72{\leq}Pr{\leq}909$), the aspect ratio ($0.5{\leq}AR=W/H{\leq}2$) and the angle of inclination ($0^{\circ}{\theta}60^{\circ}$). Mean Nusselt number distributions were obtained and effect of Reynolds number, Rayleigh number and Prandtl number on mixed convection in the horizontal channel with rectangular cavity were investigated.

• The Plant Pathology Journal
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• v.32 no.2
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• pp.168-170
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• 2016

We previously found that the antibacterial activity of silver phosphate crystals on Escherichia coli depends on their structure. We here show that the cubic form of silver phosphate crystal (SPC) can also be applied to inhibit the growth of a plant-pathogenic Pseudomonas syringae bacterium. SPC pretreatment resulted in reduced in planta multiplication of P. syringae. Induced expression of a plant defense marker gene PR1 by SPC alone is suggestive of its additional plant immunity-stimulating activity. Since SPC can simultaneously inhibit P. syringae growth and induce plant defense responses, it might be used as a more effective plant disease-controlling agent.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.19 no.4
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• pp.459-479
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• 2015

Two-dimensional steady laminar natural convection around a heat conducting and generating solid body inside a square enclosure with different thermal boundaries is performed. The mathematical model is governed by the coupled equation of mass, momentum and energy. These equations are discretized by finite volume method with power-law scheme and solved numerically by SIMPLE algorithm with under-relaxation technique. Effect of Rayleigh number, temperature difference ratio of solid-fluid, aspect ratio of solid-enclosure and the thermal conductivity ratio of solid-fluid are investigated numerically for Pr = 0.7. The flow and heat transfer aspects are demonstrated in the form of streamlines and isotherms respectively.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.52 no.3
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• pp.134-141
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• 2003

PID controllers with constant gains have been widely used in various control systems due to its powerful performance and easy implementation. But it is difficult to have uniformly good control performance in all operating conditions. In this paper, we propose a nonlinear variable PR controller with immune feedback mechanism. An immune feedback mechanism is based on the functioning of biological T-cells, they include both an active term, which controls response speed. and an inhibitive term, which controls stabilization effect. Therefore, the proposed nonlinear PID controller is based on immune responses of biological. immune feedback mechanism which is the cell mediated immunity and In order to choose the optimal nonlinear PID controller games, we also propose the tuning algorithm of nonlinear function parameter in immune feedback mechanism. To verify performance of the proposed algorithm, the speed control of nonlinear DC motor are performed. Front the simulation results, we have found that the proposed algorithm is more superior to the conventional constant fain PID controller.

• Journal of the Korean Chemical Society
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• v.15 no.2
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• pp.95-105
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• 1971

The apparent molal volumes ${\phi}_v$ of a series of homologous tetraalkylammonium chlorides, $Me_4NCl, Et_4NCl, Pr_4NCl,\;and\;Bu_4NCl$, in a series of isopropanol-water mixtures have been determined at $30^{\circ}C$ from precision density measurements using pycnometers. The values of ${\phi}_v$ extrapolated to infinite dilution give partial molal volumes $\={V}^{\circ}$s which are almost additive for successive homologues and enable one to determine the absolute individual ionic partial molal volumes. The experimental results are discussed in terrns of the varying size and surface charge of the ions and the structure of the binary solvent mixtures. The results indicate that at 0.1 mole fraction isopropanol the maximum structuredness of water causes a minimum in the tetraalkylammonium-cation partial molal volumes, while at 0.2 mole fraction the solvent structure is such that the free volumes is a minimum and the electrostrictive effect of chloride ion is a maximum.

• Journal of the Korean Chemical Society
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• v.13 no.3
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• pp.195-198
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• 1969

Determination of partial molal volumes of anilinium chloride isopropanol-water mixtures at 30.00$^{\circ}$showed a distinct minimum at 0.20 mole fraction isopropanol. This was interpreted as maximum in electrostriction effect and minimum in water structure. The depth in $\bar{V}^{\circ}$for alcohol-water mixtures was in the order MeOH > i-PrOH > EtOH, which indicated the importance of microscopic structure around ions.

• Journal of Information Display
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• v.12 no.1
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• pp.29-35
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• 2011

In this study, plasma display panels with three different cell volumes were prepared by changing the spaces between the vertical barrier ribs into two and three times the reference structure. The discharge gap and area of the segmented ITO electrode were the same for the three cases, and Ne.20%Xe gas was used. The luminance and luminance efficiency were measured using applied voltage variations. The time evolution and intensity distribution of the infrared, which are related to the vacuum ultraviolet, were observed via intensified, charged, coupled device, and the visible-light intensity profiles were observed using PR-900 to analyze the discharge phenomena in the discharge cell.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.7
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• pp.946-955
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• 1998

Local condensation heat transfer coefficients in tubes were calculated by solving momentum and energy equations for annular film with liquid entrainment. The turbulent eddy distribution across the liquid film has been proposed and the calculated heat transfer coefficients were presented. Also turbulent Prandtl number effects on condensation heat transfer were discussed from three Pr$\_$t/ models. Finally, the calculated condensation heat transfer coefficients of R22 were compared with some correlations frequency referred to in open literature. This calculation model considering liquid entrainment predicted well the in-tube condensation heat transfer coefficient of R22 than the model not considering liquid entrainment. The effect of entrainment on heat transfer was predominant for high quality and high mass flux when the liquid film was turbulent.