• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.198-198
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• 2010

The low-k SiOCH thin films were prepared by CCP-PECVD method using BTMSM(Bis-trimethylsilylmethane) precursors deposited on p-Si wafer. The structural complexity originate the complex refractive constants of the films, and resulted the elliptical polarization of the incident linearly polarized light source of Xe-ramp in the range from 190nm to 2100nm. Phase difference and amplitude ratio between s wave and p wave propagating through SiOCH thin film was studied. After annealing, the amplitude of p wave was reduced more than s wave, and phase difference between p and s wave was also reduced.

• Transactions on Control, Automation and Systems Engineering
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• v.2 no.2
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• pp.130-135
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• 2000

A two parameter model of a single fictitious weak acid with unknown dissociation constant has been successfully applied to design a neutralization system for many multi-component acid streams. But there are some processes for which above two parameter model is not satisfactory due to poor approxmation of the nonlinearity of pH process. Here, for etter control of wide class of multi-component acid streams, a three parameter model of a strong acid and a weak acid with unknown dissociation constant is proposed. The model approximates effectively three types of largest gain variation nonlinearities. Based on this model a nonlinear pH control system is designed. Parameters can eeasily estimated since their combinations appear linearly in the model equations and nonlinear adaptive control system may also be constructed just as with the two parameter model.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.5
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• pp.74-79
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• 2000

This paper presents the test result of electric vehicle to evaluate a point of difference between maximizing efficiency control and conventional constant flux control(CFX) strategy of induction motor driver. A proposed maximizing efficiency control(MEC) strategy is compared with th constant flux control strategy. The comparison test is carried out with two types of F.T.P-72 and E.P.A driving schedule. This research shown the effectiveness of an enlargement of driving distance of the electric vehicle when a maximizing efficiency control strategy adopted.

• Journal of the Korean Institute of Telematics and Electronics
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• v.7 no.4
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• pp.14-19
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• 1970

Transient phenomena in the p-n junction due to the selfheating effect of microplasma current have been investigated for the cases of small current and of large current. For the small current case, the temperature rise of the microplasma site is proportional to the current decrease and a unique time constant could be defined. However, the situation was complicated for the case of large current, and the time constant was not uniquely defined.

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2203-2207
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• 2009

Chemical equilbria of nickel chloride in HCl solution at $25\;{^{\circ}C}$ were analyzed by considering chemical equilibria, mass and charge balance equations. The activity coefficients of solutes were calculated by using Bromley equation. The necessary thermodynamic properties, such as the equilibrium constant for the formation of Ni$Cl^+$ at zero ionic strength and interaction parameter, were evaluated by applying Bromley equation to the stability constant data reported in the literature. It was found that most nickel exists as $Ni^{2+}$ in HCl solution up to 5 molality HCl. The pH values of Ni$Cl_2-HCl-H_2O$ system at $25\;{^{\circ}C}$ calculated in this study agreed well with the pH values measured by employing pH meter.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.347-349
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• 1999

We have fabricated insulating thin films using p-hexadecoxyphenol(p-Hp) that was formed phenol-formaldehyde resin of crosslinked structure from reaction with formaldehyde by LB technique. For fabricated MIM device, the possibility for insulating layers of electronic were investigated by electrical properties of their LB films according to crosslinking of LB films current-voltage (I-V) properties and frequency-capacitance (C-F) characteristics. We have provided evidence for the high insulating performance of phenol-formaldehyde thin films by the LB method. Conductivity of their LB films was as follows: pure water > 1 % aq. Formaldehyde > heat treatment, in the current-voltage (I-V) characteristics. It is demonstrated that insulation properties of crosslinked p-HP LB films were improved. In capacitance-frequency properties, the heat-treated p-HP LB films for crosslinking showed a low relative dielectric constant.

• Bulletin of the Korean Chemical Society
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• v.17 no.9
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• pp.814-819
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• 1996

In search of simple host molecules for uranyl ion which form 1: 1-type complexes with high formation constants that can be used either in extraction of uranium from seawater or in catalysis of biologically important organic reactions, the uranophile activities of dihydroxyazobenzene derivative 1 were studied. Uranyl ion and 1 form a 1: 1-type complex with a very large formation constant. The formation constant was measured at pH 7-11.6 by competition experiments with carbonate ion. From the resulting pH dependence, ionization constants of the two aquo ligands coordinated to the uranium of the uranyl complex of 1 were calculated. The ionization constants were also measured by potentiometric titration of the uranyl complex of 1. Based on these results, the pKa values of the two aquo ligands were estimated as 7.1 and 11.0, respectively. At pH 7.5-9.5, therefore, the complex exists mostly as monohydroxo species. Under the conditions of seawater, 1 possesses greater affinity toward uranyl ion compared with other uranophiles such as carbonate ion, calixarene derivatives, or a macrocyclic octacarboxylate. In addition, complexation of 1 with uranyl ion is much faster than that of the calixarene or octacarboxylate uranophiles.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.2
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• pp.260-264
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• 1987

We examine the effect of junction depth on the charge density solving numerically the general form of Poisson's equation for Gaussian $n^{+}$-p junctions. We also present an analytical model for the charge diopole due to the variation of the dielectric constant with doping.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.943-946
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• 2007

In-plane piezoelectric charge constant of Electro-Active paper (EAPap) was investigated based on direct and converse piezoelectric effects. EAPap samples were made with cellulose film with very thin gold electrode coated on both sides of the film. To characterize direct piezoelectricity of EAPap, induced charge was measured when mechanical stress was applied to EAPap. In-plane piezoelectric charge constant was extracted from the relation between induced charge and applied in-plane normal stress. To investigate converse piezoelectricity, induced in-plane strain was measured when electric field was applied to EAPap. Piezoelectric charge constant was also extracted from the relation of induced in-plane strain and applied electric field. Piezoelectric charge constants obtained from direct and converse piezoelectricity are 31 pC/N and 178 x 10-12m/V for 45 degree sample, respectively. Measured piezoelectric charge constants of EAPap provide promising potential as a piezoelectric material.

• Journal of information and communication convergence engineering
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• v.9 no.2
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• pp.217-219
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• 2011

As silicon devices shrink and their density increases, the low dielectric constant materials instead of $SiO_2$ film is required. SiOC film as low-k films was deposited by the capacitively coupled plasma chemical vapor deposition and then annealed at $300{\sim}500^{\circ}C$ to find out the properties of the dependence on the temperature and polarity. This study researched the dielectric constant using by the structure of the metal/SiOC film/p-Si, chemical shift, thickness, refractive index and hardness. The trend of reflective index was inverse proportioned the thickness, but the dielectric constant was proportioned it. The dielectric constant decreased with decreasing the thickness and the increment of the refractive index.