• Journal of the Korean Ceramic Society
• /
• v.33 no.3
• /
• pp.348-354
• /
• 1996

• 한국전자현미경학회:학술대회논문집
• /
• 2005.05a
• /
• pp.145-146
• /
• 2005

• Bulletin of the Korean Chemical Society
• /
• v.23 no.8
• /
• pp.1166-1168
• /
• 2002

• Kyungpook Mathematical Journal
• /
• v.56 no.3
• /
• pp.715-726
• /
• 2016

In this paper, we establish some new P-Q type modular equations, by using the modular equations given by Srinivasa Ramanujan.

• Kyungpook Mathematical Journal
• /
• v.56 no.1
• /
• pp.295-300
• /
• 2016

For the complex torus, there is the Riemann condition on the polarization for it to be an abelian variety. We extend this condition on the super torus for super abelian variety.

• Journal of the Korean Magnetics Society
• /
• v.6 no.3
• /
• pp.158-164
• /
• 1996

The magnetic and magneto-optical properties of the Tb/Co multilayers as a function of the layer thickness and the ratio of Tb/Co thicknesses were studied. When the thickness of Tb layer was $12{\AA}$, the maximum perpendicular anisotropy energy and the maximum thickness ratio which displays the perpendicular anisotropy were obtained. This result indicated that the Tb-Tb and Co-Co pairs as well as the Tb-Co pairs contribute to the perpendicular anisotropy. The Kerr rotation angle, $({\theta}_k)$ was proportional to the perpendicular anisotropy energy and was inversely proportional to the average spin dispersion angle, $(\alpha)$. The maximum $({\theta}_k)$ of $0.28^{\circ}$ was obtained in the film of $12{\AA}$ Tb and the thickness ratio of 1.55. The abnormal hysteresis loops were appeared during the aging treatment because the coercivity difference between the Co layer and the Tb layer was increased by the preferential oxidation of Tb.

• Journal of Korean Ophthalmic Optics Society
• /
• v.11 no.3
• /
• pp.225-229
• /
• 2006

In our angle configuration, several peculiar characteristic behaviors of MR could be observed, the mixing of positive MR(PMR) and negative MR(NMR) in the inclined sample was observed. The complete mixing angle, ${\phi}_{mix}$ as a function of inclination angle, ${\theta}$ was observed to fit well to the relation of ${\phi}_{mix}=tan^{-1}(1+tan{\theta})$ in nickel films. The above theoretical relation was obtained by decomposing the magnetic field into the components parallel and perpendicular to the current flow and identifying ${\phi}_{mix}$ as the angle satisfying that the above two components of magnetic field were identical. We also observed that the data of ${\phi}_{mix}$ did not satisfy the above theoretical relation in the iron film. This was explained by the fact that the growth direction in the iron film was an intermediate direction of magnetization, while the growth direction in the nickel film was an easy axis of magnetization.

• Journal of The Korean Astronomical Society
• /
• v.50 no.3
• /
• pp.61-70
• /
• 2017

We study the angular correlation function of bright ($K_s{\leq}19.5$) Extremely Red Objects (EROs) selected in the Subaru GTO 2$deg^2$ field. By applying the color selection criteria of $R-K_s$ > 5.0, 5.5, and 6.0, we identify 9055, 4270, and 1777 EROs, respectively. The number density is consistent with similar studies on the optical - NIR color selected red galaxies. The angular correlation functions are derived for EROs with different limiting magnitude and different $R-K_s$ color cut. When we assume that the angular correlation function $w({\theta})$ follows a form of a power-law (i.e., $w({\theta})=A{\theta}^{-{\delta}}$), the value of the amplitude A was larger for brighter EROs compared to the fainter EROs. The result suggests that the brighter, thus more massive high-redshift galaxies, are clustered more strongly compared to the less massive galaxies. Assuming that EROs have redshift distribution centered at ~ 1.1 with ${\sigma}_z=0.15$, the spatial correlation length $r_0$ of the EROs estimated from the observed angular correlation function ranges ${\sim}6-10h^{-1}Mpc$. A comparison with the clustering of dark matter halos in numerical simulation suggests that the EROs are located in most massive dark matter halos and could be progenitors of $L_{\ast}$ elliptical galaxies.

• The Journal of Korean Academy of Prosthodontics
• /
• v.37 no.3
• /
• pp.358-374
• /
• 1999

This study measured the relative displacements of the five-unit fixed partial dentures as cast with the same fixed partial dentures sectioned and assembled by investment-soldering, solder-ing stand-soldering, and cast-joining techniques A total of fifteen specimens using a type IV gold alloy were one-piece cast as control and then sectioned and assembled five test specimens for each method were prepared. A computerized three dimensional coordinate measuring machine and specially designed cylinder for this study were used. Displacement was defined by six displacement variables for the each of cylinders incorporated in each casting: three component displacements(${\Delta}Lx,\;{\Delta}Ly,\;and\;{\Delta}Lz$) and rotational displacements(${\Delta}{\theta}x,\;{\Delta}{\theta}y,\;{\Delta}{\theta}z$). The global displacement was computed using the mathematical formula ${\Delta}R$ = Global displacement =$\sqrt{{(x'-x)}^2+{(y'-y)}^2+{(z'-z)}^2}$ Under the conditions of this study, the following conclusions were drawn: 1. The investment-soldering group showed the largest mean value of final global displacements, followed by stand-soldering group, cast-joining group and one-piece cast group. However, between the mean values of final global displacement for the cast-joining group and one-piece cast group, there was no significant difference. 2. For investment-soldering and stand-soldering groups, the greater global displacements were recorded in soldering phase than in indexing or investing phase. 3. For one-piece cast group, the displacements occured mostly in the casting phase. And for cast-joining group, there was no significant difference in global displacements among the fabricating procedures. 4. Intercentroidal distance decreased in framework-patterning, solder-indexing, solder-standing, and soldering phases, but increased in investment block-investing and casting phases. 5 Specially designed cylinder for touch-trigger type coordinate measuring machine was validated.

• Physical Therapy Korea
• /
• v.15 no.4
• /
• pp.70-79
• /
• 2008

The purpose of this study was to find out the effects of electroencephalograph (EEG) power and coherence on cognitive function in normal elderly, non-demented elderly with mild cognitive impairment, and demented elderly during working cognition tasks. Forty elderly women (19 demented elderly, 10 non-demented elderly with mild cognitive impairment, 11 norma1 elderly) participated in this study, All subjects performed working cognition tasks with Raven's CPM while EEG signal was recorded, EEGs were measured continuously at rest and during the working cognition task. EEG power and coherence was computed over 21 channels: right and left frontal, central, parietal, temporal and occipital region. We found that there were more correct answers among normal elderly women than in other groups Owing the working cognition task, ${\Theta}$ wave at Fp1, Fp2 and F8, a wave at Fp2, ${\beta}$ wave at Fp1, Fp2. F4 and F8 of the frontal region was increased significantly in the demented elderly group. On the other hand. ${\Theta}$ wave at Fp1, Fp2 and F7, ${\beta}$ wave at Fp1, Fp2, F3 and F7 of the frontal region was increased significantly in the group of non-demented elderly with mild cognitive impairment. In contrast. in the normal elderly group, all of the ${\Theta}$ wave and ${\beta}$ wave at Fp1, Fp2, F3, F4, F7 and F8 of the frontal region (except ${\beta}$ wave at F3) was increased significantly, These results suggest that the nerves in prefrontal and right hemisphere regions were most active in the demented elderly group during problem solving, and the nerves in the prefrontal and left hemisphere lobe were most active in the group of non-demented elderly with mild cognitive impairment. In contrast, me majority of nerves in the frontal region were active in the normal elderly group.