• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.621-662
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• 2006

• The Bulletin of The Korean Astronomical Society
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• v.31 no.2
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• pp.64.1-64.1
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• 2006

• Proceedings of the PSK Conference
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• 2000.04a
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• pp.216.1-216.1
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• 2000

• Proceedings of the PSK Conference
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• 2002.04a
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• pp.150.1-150.1
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• 2002

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1165-1166
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• 2006

An experiment was carried out to investigate the effect of Ba Stearate as a reducing agent on the magnetic and physical properties of anisotropic $BaFe_2-W$ type ferrite magnets. It was found that the magnetic properties of $BaO{\cdot}8.5Fe_2O_3$ were improved by adding 0.3 wt% of Ba Stearate, 0.5 wt% of $SiO_2$, and 0.5 wt% of CaO together. The optimum conditions for making magnets were as follows; semisintering condition: $1350^{\circ}C{\times}4.0$ h in nitrogen gas atmosphere, drying condition: $180^{\circ}C{\times}2.0$ h in air, sintering condition: $1160^{\circ}C{\times}1.5$ h in nitrogen gas atmosphere. Magnetic and physical properties of a typical sample were $J_m$ = 0.46 T, $J_r$ = 0.43 T, $H_{cJ}$ = 182.3 kA/m, $H_{cB}$ = 177.2 kA/m, $(BH)_{max}$ = 33.8 kJ/$m^3$, $T_C$ = $495^{\circ}C$ and $K_A$ = $2.65{\times}10^5\;J/m^3$ and $H_A$ = 1332 kA/m.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1639-1641
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• 1996

Polyirnide thin films were fabricated an using vapor deposition polymerization apparatus, and their FT-IR and TGA characteristics were investigated. The peaks of $720cm^{-1}$ and $1380cm^{-1}$ show C=O stretch mode and C-N stretch mode, and that of the cured polyimide at $300^{\circ}C$ were saturated. TGI(Thormogravi metric index) was showed at $459^{\circ}C$ from reaserch of thermal resistivity characteristics by TGA.

• Korean Journal of Optics and Photonics
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• v.4 no.2
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• pp.195-199
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• 1993

The output energy of Rh-6G dye laser was enhanced by the energy transfer in the mixture of Rh-6G and C-545. The laser was pumped by coaxial flashlamp filled argon gas. The optimum concentration of Rh-6G was $10_-4mol/l$ without mixing. The output energy was enhanced about 70 % at 0.4 % C-545 mixture with respect to the concentration of Rh-6G. The peak output power and the output energy were 27 kW and 50 mJ at the pumping energy of 346 J.

• Korean Journal of Agricultural Science
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• v.11 no.1
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• pp.25-33
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• 1984

This experiment carried out to obtain the thermophilic yeast, suitable for ethanol fermentation, and two usable strain were isolated. And microbial characteristics of these strains were investigated, and ethanol fermentation tested. The results obtained were as follows; 1. The selected yeasts were identified D-71 with Saccharomyces cerevisiae, and J-515 with Saccharomyces fermentati. 2. The strains D-71 and J-515 were showed the highest ethanol fermentation activity in the crushed corn mash of high concentration at $35^{\circ}C$, and showed the slightly lower at $40^{\circ}C$ than in the case of $35^{\circ}C$. 3. The strains D-71 and J-515 were showed the very higher ethanol fermentation activity than that of compared strain at $35^{\circ}C$ and $40^{\circ}C$, and at these temperature, fermentation period was a little bit of short. 4. On fermentation test using D-71 and J-515, the residual total sugar in the mash was very lower at $35^{\circ}C$.

• The Pure and Applied Mathematics
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• v.24 no.2
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• pp.69-77
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• 2017

If q(z) is a polynomial of degree n with all zeros in the unit circle, then the self-reciprocal polynomial $q(z)+x^nq(1/z)$ has all its zeros on the unit circle. One might naturally ask: where are the zeros of $q(z)+x^nq(1/z)$ located if q(z) has different zero distribution from the unit circle? In this paper, we study this question when $q(z)=(z-1)^{n-k}(z-1-c_1){\cdots}(z-1-c_k)+(z+1)^{n-k}(z+1+c_1){\cdots}(z+1+c_k)$, where $c_j$ > 0 for each j, and q(z) is a 'zeros dragged' polynomial from $(z-1)^n+(z+1)^n$ whose all zeros lie on the imaginary axis.

• Progress in Superconductivity
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• v.1 no.2
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• pp.85-88
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• 2000

The temperature dependent Josephson critical current $J_c(T)/J_c(0)$ between high $T_c$ superconductors along the a-axis is theoretically studied. The interface influence on the wave functions of quasi-particles is included in the theory within the framework of the two-dimensional t-J model. It is found that the experimental results can be satisfactorily explained by the present model with d wave pairing symmetry.