• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1527-1530
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• 2005

In the semiconductor and optical industry the non-contact transportation is required for reducing the damages. The ultrasonic levitation is the solution of the problem. In this paper, the ultrasonic levitation system and 3 disk-type stator for levitation various object are proposed. The vibration modes of disks are analyzed with FEM and designed with the analysis results. The 3D vibration profiles of the disks are measured by Laser scanning vibrometer for verifying the vibration characteristics of the system. The amplitudes of the disks and the levitation heights of object are measured for evaluating the performance.

• Atmosphere
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• v.29 no.2
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• pp.197-211
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• 2019

The observational sensitivity of dual-polarization weather radar was quantitatively analyzed by using two different pulse widths. For this purpose, test radar scan strategy which consisted of consecutive radar scan using long (LP: $2{\mu}s$) and short (SP: $1{\mu}s$) pulses at the same elevation angle was employed. The test scan strategy was conducted at three operational S-band dual-polarization radars (KSN, JNI, and GSN) of Korea Meteorological Administration (KMA). First, the minimum detectable reflectivity (MDR) was analyzed as a function of range using large data set of reflectivity ($Z_H$) obtained from JNI and GSN radars. The MDR of LP was as much as 7~22 dB smaller than that of SP. The LP could measure $Z_H$ greater than 0 dBZ within the maximum observational range of 240 km. Secondly, polarimetric observations and the spatial extent of radar echo between two pulses were compared. The cross-polar correlation coefficient (${\rho}_{hv}$) from LP was greater than that from SP at weak reflectivity (0~20 dBZ). The ratio of $Z_H$ (> 0 dBZ) and ${\rho}_{hv}$(> 0.95) bin to total bin calculated from LP were greater than those from SP (maximum 7.1% and 13.2%). Thirdly, the frequency of $Z_H$ (FOR) during three precipitation events was analyzed. The FOR of LP was greater than that of SP, and the difference in FOR between them increased with increasing range. We conclude that the use of LP can enhance the sensitivity of polarimetric observations and is more suitable for detecting weak echoes.

• Applied Biological Chemistry
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• v.48 no.4
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• pp.364-369
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• 2005

This study was performed to elucidate substrate specificity to the locust bean gum galactomannan by Trichoderma harzianum ${\beta}-mannanase$. The medium composition for enzyme production were determined 3% cellulose, 3% corn steep liquor, 1% $KH_2PO_4$, 0.2% $(NH_4){_2}SO_4$, and incubated for 115 hr at $28^{\circ}C$. The ${\beta}-mannanase$ exhibited maximum activity at pH 4.5 and $60^{\circ}C$. Locust bean gum galactomannan was hydrolyzed by the ${\beta}-mannanase$, and then hydrolysates separated by activated carbon column chromatography. The main hydrolysates were composed of D.P 4 and 7 galactosyl mannooligosaccharides by TLC. For the elucidate the structure of D.P 4 and 7 oligosaccharides, methylation analysis was performed. D.P 4 and 7 were identified as M-M-M-M and M-M-M-M-M (G- and M-represent ${\alpha-1,6-D-galactosidic\;and\;{\beta}-1,4-mannosidic$ linkages, respectively). //G-G To investigate the effects of locust bean gum galactosyl mannooligosaccharides on the in vitro growth of B. longum, B. bifidum, B. infantis, and B. breve, Bifidobacterium spp. were cultivated individually on the modified-MRS medium containing carbon source such as D.P 4 and 7 galactosyl mannooligosaccharides, respectively. B. longum grew up 3.4-fold and 4.3-fold more effectively by the replacement of D.P 4 and 7 galactosyl mannooligosaccharides as the carbon source in a comparasion of standard MRS.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.1
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• pp.51-60
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• 2015

Purpose: To determine the effect of marketed multipurpose contact lens solutions (MPSs) on human corneal epithelial cells (HCEpiCs) toxicity by using image analysis. Methods: HCEpiCs were exposed six MPSs (product A-F) at 0.05~50% for 2h, 12h, 24h, and 48h respectively. HCEpiCs were fixed and stained with Draq5 after exposure with MPSs, and the cell viability and apoptosis were evaluated by using confocal microscope and ImageXpress UltraTM. Results: Viabilities of HCEpiCs exposed to MPS A-F for a 2h were not affected, while reductions (52~75%) in cell viability over a 12h exposure of MPS B, MPS C, MPS D and MPS F, and significant more reductions (29~73%) over a 24h and 48h-exposure. Apoptosis of HCEpiC was not affect over a 12h MPS exposure, however was significantly increased (199~526%) over 24h and 48h MPS exposure. Among the products MPS D, E and F reduced viability of HCEpiCs and apoptosis increased more than MPS A (p<0.05). Conclusions: Lower concentration of MPSs have not an cytotoxic effect on HCEpiCs, however higher concentration of MPSs induce apoptosis and reduce viability of HCEpiCs. Therefore, it need to develop MPS having antimicrobial effectiveness with low cytotoxicity.

• Bulletin of the Korean Chemical Society
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• v.35 no.7
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• pp.2086-2092
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• 2014

Two novel coordination compounds $[Cu_2(pypya)_3(H_2O)_2]{\cdot}Cl{\cdot}(H_2O)_5$ (1) and $\{[Cd(pypya)(ta)_{1/2}]{\cdot}H_2O\}_n$ (2) (Hpypya=2-(3-(pyridin-2-yl)-1H-pyrazol-1-yl)acetic acid, $H_2ta$=terephthalic acid) were synthesized and characterized by single X-ray diffraction. Structure determination reveals that complex 1 and complex 2 crystallize in the triclinic system, with the P-1 space group. The asymmetric unit of 1 contains two Cu(II) ions, and their coordination modes are different. These units of complex 1 are linked together via hydrogen bonds and ${\pi}-{\pi}$ interactions, and the 3D structure of complex 1 was formed. Complex 2, a mononuclear Cd(II) coordination compound, has a 2D structure which was constructed via coordination bonds. TGA and fluorescence spectra analysis of complex 1 and complex 2 have also been studied. In addition, the geometry parameters of complex 1 have been optimized with the B3LYP method of density functional theory (DFT) to explain its coordination behavior. The electronic properties of the complex 1 and ligand Hpypya have been investigated based on the nature bond orbital (NBO) analysis at the B3LYP level of theory. The result verifies that the synergistic effect have occurred in the compound.

• Journal of Korean Society of Forest Science
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• v.73 no.1
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• pp.9-13
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• 1986

Karyotypes are described for Juniperus rigida Sieb. et zucc, in two provenances of Gyeong-nam and Choong-puk. Chromosome numbers of two provenances, are 2n=22. The most common feature of mitotic chromosomes was shown at the chromosome 7, which has secondary constriction on the short arm. And the most differential chromosome was shown at chromosome 9 from Gyeong-nam and chromosome 5 from Choong-puk provenance which bore secondary constriction. The karyotype formulae are as follows; Gyeong-nam, Jinyang provenance race is $$K(2n)=22=2A^m+2B^m+2C^m+2D^{sm}+2E^{st}+2F^m+2^{sc}G^m+2H^m+2^{sc}I^t+2J^{st}+2K^m$$ Choong-puk, Jechun provenance race is $$K(2n)=22=2A^m+2B^m+2C^m+2D^{st}+2^{sc}E^{sm}+2F^m+2^{sc}G^m+2H^m+2I^m+2J^{st}+2K^{sm}$$.

• 한국전산유체공학회:학술대회논문집
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• 2009.04a
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• pp.21-26
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• 2009

Ice accretion is one of the potential hazards in airplane flight, adversely affecting aircraft aerodynamic. There are two distinct icing analysis that can be simulated. One is predicting the effect of ice on the aerodynamic performance of airfoils when ice geometry is known. The other is simulating ice accretion. This work presents the method of icing accretion analysis. This work presents an Eulerian approach to calculate the droplet collection efficiency on the 2D airfoil. The initial flow solution are obtained the FLUENT and copled with droplet motion in the ambient condition.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1060-1062
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• 1993

This paper presents the dynamic analysis method of a linear induction motor by finite element method. For simulation of dynamic performance, a step by step process with respect to time is used with external voltage source and motional equation. Movement is taken into account by a combination of mesh distortion and remeshing technique.

• Bulletin of the Korean Chemical Society
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• v.35 no.3
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• pp.899-904
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• 2014

The atomic structures and electronic properties of six classical and nonclassical $H_2O$@$C_{24}$ fullerene regioisomers are systematically studied using the hybrid density functional B3LYP method and M06-2X method with empirical dispersion in conjunction with the 6-31G(d,p) basis sets. The charge transfer, frontier orbitals, dipole moment, energy gap between the HOMO and LUMO, and volume change of the $C_{24}$ cage are analyzed upon encapsulation of a $H_2O$ molecule in each $C_{24}$ regioisomer. All encapsulation processes are endothermic and the relative stabilities of six $C_{24}$ fullerene regioisomers change upon encapsulation of $H_2O$.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.232-234
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• 2005

This paper will produce a practical, accurate method for computing the equipment forced outages rate (FOR) based on 10 years of historical equipment outages data. Also, the location and weather conditions on outages are included. The computed FOR are ranked as 4 groups (presumably high, medium, low & very low) depending on the frequency (up to # times per year) and a consistent framework for transmission reliability performance table is developed based on these groupings. Our intent is to use this framework as guidelines for contingency analysis criteria in system planning / operation departments. The concepts are illustrated on the 2005 KEPCO power system.