• Bulletin of the Korean Mathematical Society
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• v.60 no.4
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• pp.905-913
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• 2023

Suppose that M is a strictly convex hypersurface in the (n + 1)-dimensional Euclidean space 𝔼ⁿ⁺¹ with the origin o in its convex side and with the outward unit normal N. For a fixed point p ∈ M and a positive constant t, we put 𝚽_t the hyperplane parallel to the tangent hyperplane 𝚽 at p and passing through the point q = p - tN(p). We consider the region cut from M by the parallel hyperplane 𝚽_t, and denote by I_p(t) the (n + 1)-dimensional volume of the convex hull of the region and the origin o. Then Schneider's characterization theorem for ellipsoids states that among centrally symmetric, strictly convex and closed surfaces in the 3-dimensional Euclidean space 𝔼³, the ellipsoids are the only ones satisfying I_p(t) = 𝜙(p)t, where 𝜙 is a function defined on M. Recently, the characterization theorem was extended to centrally symmetric, strictly convex and closed hypersurfaces in 𝔼ⁿ⁺¹ satisfying for a constant 𝛽, I_p(t) = 𝜙(p)t^𝛽. In this paper, we study the volume I_p(t) of a strictly convex and complete hypersurface in 𝔼ⁿ⁺¹ with the origin o in its convex side. As a result, first of all we extend the characterization theorem to strictly convex and closed (not necessarily centrally symmetric) hypersurfaces in 𝔼ⁿ⁺¹ satisfying I_p(t) = 𝜙(p)t^𝛽. After that we generalize the characterization theorem to strictly convex and complete (not necessarily closed) hypersurfaces in 𝔼ⁿ⁺¹ satisfying I_p(t) = 𝜙(p)t^𝛽.

• Journal of the Institute of Convergence Signal Processing
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• v.15 no.2
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• pp.48-54
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• 2014

For the element ${\alpha}{\in}GF(p^n)$, two kinds of bases are known. One is a conventional polynomial basis of the form $\{1,{\alpha},{\alpha}^2,{\cdots},{\alpha}^{n-1}\}$, and the other is a normal basis of the form $\{{\alpha},{\alpha}^p,{\alpha}^{p^2},{\cdots},{\alpha}^{p^{n-1}}\}$. In this paper we consider the method of generating normal bases which construct the finite field $GF(p^n)$, as an n-dimensional extension of the finite field GF(p). And we analyze the code sequence generating algorithm and derive the implementation functions of code sequence generator based on the normal bases. We find the normal polynomials of degrees, n=5 and n=7, which can generate normal bases respectively, design, and construct the code sequence generators based on these normal bases. Finally, we produce two code sequence groups(n=5, n=7) by using Simulink, and analyze the characteristics of the autocorrelation function, $R_{i,i}(\tau)$, and crosscorrelation function, $R_{i,j}(\tau)$, $i{\neq}j$ between two different code sequences. Based on these results, we confirm that the analysis of generating algorithms and the design and implementation of the code sequence generators based on normal bases are correct.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1261-1263
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• 1997

Two kinds of optically-triggered p-i-n switches with planar and V-groove structures have been fabricated with gold-doped silicon. The V-groove device exhibits a higher threshold voltage and is more sensitive to light. The minimum optical power indicates that a certain minimum illumination is required to optically turn on the silicon p-i-n devices.

• Journal of the Korea Society of Computer and Information
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• v.17 no.4
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• pp.139-145
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• 2012

Generally, Quicksort selects the pivot from leftmost, rightmost, middle, or random location in the array. This paper suggests Quicksort using middle range pivot $P_0$ and continually divides into 2. This method searches the minimum value $L$ and maximum value $H$ in the length n of list $A$. Then compute the initial pivot key $P_0=(H+L)/2$ and swaps $a[i]{\geq}P_0$,$a[j]<P_0$ until $i$=$j$ or $i$>$j$. After the swap, the length of list $A_0$ separates in two lists $a[1]{\leq}A_1{\leq}a[j]$ and $a[i]{\leq}A_2{\leq}a[n]$ and the pivot values are selected by $P_1=P_0/2$, $P_2=P_0+P_1$. This process repeated until the length of partial list is two. At the length of list is two and $a$[1]>$a$[2], swaps as $a[1]{\leftrightarrow}a[2]$. This method is simpler pivot key process than Quicksort and improved the worst-case computational complexity $O(n^2)$ to $O(n{\log}n)$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.11
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• pp.974-979
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• 2009

We studied solution-processed single-layered phosphorescent organic light-emitting diodes (PHOLEDs), doped with ionic salt and treated with simultaneous electrical and thermal annealing. Because the simultaneous annealing causes the accumulation of salt ions at the electrode surfaces, the energy levels of the organic molecules are bent by the electric fields due to the adsorbed ions, i.e., the simultaneous annealing can induce the proper formation of an ionic p-i-n structure. As a result, an ionic p-i-n PHOLED with a peak luminescence of over ${\sim}35,000\;cd/m^2$ and efficiency of 27 cd/A was achieved through increased and balanced carrier-injections.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.7
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• pp.69-76
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• 1995

A new device structure has been developed for p-i-n switches. In this structure, the phosphorus-diffused n$^{+}$ layter adjacent to the boron-doped anode is used to short the p$^{+}$ anode-channel(i-region). This change in the anode electrode structure results in a significant improvement in the threshold voltage-to-holding voltage($V_{Th}/V_{h}$) ratio, which is due to the suppression of the hold injection from the anode by the n$^{+}$ layer. The shorted anode p-i-n devices of a 100 .mu.m channel length show an extremely high threshold voltage in the 250~300 V range and a low holding voltage in the 5~9 V range. These features of the device are expected to acdelerate their practical application to power switching circuits.

• Bulletin of the Korean Mathematical Society
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• v.33 no.3
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• pp.419-425
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• 1996

Let ${X, X_n, n \geq 1}$ be a sequence of independent and identically distributed(i.i.d) random variables with EX = 0 and $E$\mid$X$\mid$^p < \infty$ for some $p \geq 1$. Let ${a_{ni}, 1 \leq i \leq n, n \geq 1}$ be a triangular arrary of constants. The almost sure(a.s) convergence of weighted sums $\sum_{i=1}^{n} a_{ni}X_i$ can be founded in Choi and Sung[1], Chow[2], Chow and Lai[3], Li et al. [4], Stout[6], Sung[8], Teicher[9], and Thrum[10].

• Biomedical Science Letters
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• v.9 no.3
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• pp.145-150
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• 2003

In the intestinal mucosa, mast cells are thought to be responsible for the expulsion of parasites. We investigated the relationship of worm expulsion and mast cells in C3H/HeN and BALB/c mice infected with Echinostoma hortense. In addition, we examined whether the worm recovery rate was associated with the strain of mice, and whether a toluidine stain and immunohistochemistry using the c-kit antibody was effective in the detection of mast cells. In order to investigate the mucosal immune response of C3H/HeN and BALB/c mice, each mouse was infected orally with 30 E. hortense metacercariae. Then, the number of mucosal mast cells and worm recovery rates was observed in experimentally infected mouse strains between 1 week and 8 weeks post infection (PI). Mucosal mast cells were increased in 3 weeks P.I. in C3H/HeN and BALB/c mice. On the other hand, only mucosal goblet cells and worm recovery rates correlated in C3H/HeN mice (P=0.0482). Worm recoveries in C3H/HeN mice were 65.7$\pm$5.6, 53.3$\pm$5.4 and 6.7$\pm$0.6 in week 1, 2, and 3 P.I. and strongly decreased in week 3 P.I. Worm recoveries in BALB/c mice were 23.0$\pm$2.5, 10.0$\pm$1.0, and 6.7$\pm$0.6% in week 1, 2, and 3 P.I. and gradually decreased from week 1 P.I. to week 3 P.I. Worm recoveries in C3H/HeN mice were significantly higher than in BALB/c mice (P<0.00l). The number of mast cells in C3H/HeN and BALB/c mice using the anti-c-kit antibody reached to a peak in week 3 P.I. and recovered as normal level in week 5 P.I. and 6 P.I. The number in E. hortense-infected C3H/HeN mice (P=0.0015) was higher than in E. hortense-infected BALB/c mice (P=0.01) compared with the control group. There were significant differences in the number of mast cells among regions of the intestine in in C3H/HeN mice (P<0.05) but not in BALB/c mice (P>0.05). Immunohistochemistry using the anti-c-kit antibody was significant method as an examination of the number of mast cells (P=0.0002). In conclusion, the present study demonstrated that mast cells play an important role in worm recovery, and immunohistochemistry using the anti-c-kit antibody was superior to toluidine stain as an examination of mast cells.

• Honam Mathematical Journal
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• v.45 no.4
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• pp.678-681
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• 2023

Let G be a cyclic group of prime power order p^k, and let I be the augmentation ideal of the integral group ring ℤ[G]. We define a derivation on ℤ/p^kℤ[G], and show that for 2 ≤ n ≤ p, an element α ∈ I is in Iⁿ if and only if the i-th derivative of the image of α in ℤ/p^kℤ[G] vanishes for 1 ≤ i ≤ (n - 1).

• Korean Journal of Optics and Photonics
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• v.14 no.2
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• pp.184-188
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• 2003

We fabricated a P-I-i-I-N $GaAs/Al_{0.35}Ga_{0.65}As$waveguide phase modulator with significant phase shift for the TE mode but negligible for the TM mode. We selected the P-I-i-I-N structure to cause a phase shift about the TM mode. The wavelength of $\lambda=1.55$\mu\textrm{m}$ was measured for both the TE and TM modes, respectively. As a result, the measured phase shift efficiency ($\Delta\phi$) by using the Fabry-Perot resonance method was $7.9^{\circ}/V.mm$ for TE-polarized light. Also, no modulation was observed for TM-polarized light.