• The Pure and Applied Mathematics
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• v.2 no.2
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• pp.127-132
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• 1995

[1] Show that ∫$\_$0/$\^$1/ [∫$\_$0/$\^$1/ f($\chi$,y)dy] d$\chi$ = ∫$\_$0/$\^$1/[∫$\_$0/$\^$1/ f($\chi$,y)d$\chi$] Counterexample: If pk denotes the k-th prime number, let S(pk) = (equation omitted), let S = ∪$\_$k=1/$\^$$\infty$/ S(pk), and let Q = [0, 1]${\times}$[0, 1]. Define f on Q as follows; f($\chi$, y) = 0 ($\chi$, y)$\in$S, f($\chi$, y) = 1 ($\chi$, y)$\in$Q - S.(omitted)

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2007.04a
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• pp.128-129
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• 2007

$ZnS/Na_3AlF_6$ multi-layer thin film were produced by evaporation system. ZnS were selected as a high refractive index material and $Na_3AlF_6$ were selected as low refractive index material. Optical properties including color effect were systematically studied in terms of different optical thickness by spectrophotometer. In oder to compare with experimental data, the Essential Macleod Program(EMP) was adopted that simulation program. The thin film consisting of $ZnS/Na_3AlF_6$ multi-layer show the wave length of $530{\sim}600nm$, typically color range between purple, blue, green. It was confirmed that this experimental result was well matched with simulation data.

• Journal of applied mathematics & informatics
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• v.34 no.5_6
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• pp.435-441
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• 2016

Let G be a graph, and let g, f be two nonnegative integer-valued functions defined on V (G) with g(x) ≤ f(x) for each x ∈ V (G). A graph G is called a fractional (g, f, n)-critical graph if after deleting any n vertices of G the remaining graph of G admits a fractional (g, f)-factor. In this paper, we obtain a binding number condition for a graph to be a fractional (g, f, n)-critical graph, which is an extension of Zhou and Shen's previous result (S. Zhou, Q. Shen, On fractional (f, n)-critical graphs, Inform. Process. Lett. 109(2009)811-815). Furthermore, it is shown that the lower bound on the binding number condition is sharp.

• Bulletin of the Korean Mathematical Society
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• v.47 no.1
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• pp.113-119
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• 2010

If f is M-harmonic and integrable with respect to a weighted radial measure $\upsilon_{\alpha}$ over the unit ball $B_n$ of $\mathbb{C}^n$, then $\int_{B_n}(f\circ\psi)d\upsilon_{\alpha}=f(\psi(0))$ for every $\psi{\in}Aut(B_n)$. Equivalently f is fixed by the weighted Berezin transform; $T_{\alpha}f = f$. In this paper, we show that if a function f defined on $B_n$ satisfies $R(f\circ\phi){\in}L^{\infty}(B_n)$ for every $\phi{\in}Aut(B_n)$ and Sf = rf for some |r|=1, where S is any convex combination of the iterations of $T_{\alpha}$'s, then f is M-harmonic.

• Kyungpook Mathematical Journal
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• v.52 no.4
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• pp.495-511
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• 2012

In this paper, we prove some inequalities in terms of G$\hat{a}$teaux derivatives for convex functions defined on linear spaces and also give improvement of Jensen's inequality. Furthermore, we give applications for norms, mean $f$-deviations and $f$-divergence measures.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.7
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• pp.615-627
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• 1991

In this paper the relative magnitudes of the 1/f noise constants were experimentally investigated in the plana type's resistors fabricated with the different type's semicondector materials, and a new measurement technique for the 1/f noise in the semiconductor plana type's resistors may be located at the semiconductor and silicon dioxde.

• Journal of the Chungcheong Mathematical Society
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• v.22 no.2
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• pp.141-148
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• 2009

We consider various algorithms calculating best onesided simultaneous approximations. We assume that X is a compact subset of $\mathbb{R}^{m}$ satisfying $X=\overline{intX}$, S is an n-dimensional subspace of C(X), and $\mu$ is any 'admissible' measure on X. For any l-tuple $f_1,\;{\cdots},\;f_{\ell}$ in C(X), we present various ideas for best approximation to F from S(F). The problem of best (both one and two-sided) approximation is a linear programming problem.

• Journal of the Chungcheong Mathematical Society
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• v.24 no.2
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• pp.267-271
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• 2011

Let 0 < s < 1. For $f^{\ast}$ representing the symmetric radial decreasing rearrangement of f, we build up a fractional version of Polya-$Szeg{\ddot{o}}$ inequality: $${\int}_{\mathbb{R}^n}{\mid}(-\Delta)^{s/2}f^{\ast}(x){\mid}^2dx{\leq}{\int}_{\mathbb{R}^n}{\mid}(-\Delta)^{s/2}f(x){\mid}^2dx$$.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.5
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• pp.525-532
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• 1992

Fluorine-doped YBaS12TCuS13TOS17-xTFS1yT superconducting materials with y varing two orders of magnitude form 0.02 to 2.0 have been prepared by a sol-gel process by using metal nitrate salts, sodium hydroxide and sodium fluoride. Fluorine contents have been measured using an ion-selective electrode. All fluorine doped as reactant were found to be present in the resulted samples. From the observation of XRD it has been concluded that the samples with y 0.2 formed simply the single phase of perovskite structure, whereas those with y 0.5 yielded together some compounds such as BaFS12T, YFS13T and CuO in the resulted samples. The observation of solid state S019TF NMR has been carried out in order to check whether fluorine was actually incorporated into the lattice sites, and the experimental results revealed that the mole ratio of fluorine incorporated into the lattice sites of YBaS12TCuS13TOS17-xT was approximately 0.2 per mole of the compound. Also electrical resistivity measurement indicated that onset transition temperature has the tendency to increase slightly with increasing y in the dilute region as y 0.2.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.3 no.4
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• pp.222-230
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• 1991

Conjugate heat transfer by steady laminar natural convection from a conducting tube with two vertical axial fins has been studied by a finite difference numerical procedure under basic conditions; $Ra=10_6$, Pr = 5 and $L_F=0.15$. The maximum local tube Nusselt number appears at ${\theta}=140^{\circ}$ for $L_F=0.06$, at ${\theta}=130^{\circ}$ for $L_F=0.30$ and at ${\theta}=120^{\circ}$ for $L_F=0.30$, $L_F=0.06$, respectively. The maximum mean Nusselt number shows at $L_F=0.18$ for the downward fin and at $L_F=0.12$ for the upward fin. Therefore the optimized fin length is $L_F{\approx}0.15$ under these conditions. At $L_F=0.15$, the mean Nusselt number by increasing Rayleigh number is remarkably increased for downward fin and then is slowly increased except for downward fin, it by increasing Prandtl number is apparently increased at $Pr{\leq}2$, and slightly increased at Pr>2.