• 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].

• International Journal of Contents
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• v.4 no.3
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• pp.35-40
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• 2008

Recently, almost games are using the 3D environment. Therefore, it required strongly that well-structured 3D engine or tools for development of some complicate 3D applications efficiently. In this paper, we design and implement a 3D engine (PLay engine) using the DirectX 9 SDK of the Microsoft corporation. The PLay engine has independent module structure, which has object oriented characteristics. and has not only 3D rendering functions but efficient algorithms. Moreover, we implement some tools what has compatibility with our engine for convenience. Therefore, it helps development of a 3D application easily and efficiently. We also describe each module with 2-layer structure, and each tool with compatible module, and make a simple game using PLay engine for testify.

• Journal of the Chungcheong Mathematical Society
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• v.34 no.2
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• pp.181-188
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• 2021

Let X be a nondegenerate reduced closed subscheme in ℙⁿ. Assume that π_q : X → Y = π_q(X) ⊂ ℙ^n-1 is a generic projection from the center q ∈ Sec(X) \ X where Sec(X) = ℙⁿ. Let Z be the singular locus of the projection π_q(X) ⊂ ℙ^n-1. Suppose that I_X has the almost minimal presentation, which is of the form R(-3)^β_2,1 ⊕ R(-4) → R(-2)^β_1,1 → I_X → 0. In this paper, we prove the followings: (a) Z is either a linear space or a quadric hypersurface in a linear subspace; (b) $H^1({\mathcal{I}_X(k)})=H^1({\mathcal{I}_Y(k)})$ for all k ∈ ℤ; (c) reg(Y) ≤ max{reg(X), 4}; (d) Y is cut out by at most quartic hypersurfaces.

• The Korean Journal of Ceramics
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• v.5 no.4
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• pp.375-378
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• 1999

In tho XRD study of $56ZrF_4 \cdot34BaF_2 \cdot4AIF_3 \cdot(6-x)LaF_3 \cdotxLnF_3$ glassdLn=Ce, Nd, Gd, Th), halo pattern charactarktic fo an amorphous sample appeared. When the halo peak angle ($\theta_p$) was converted into a wavenumber with $Qp=4\pi sinG\pi/\lambda(\lambda$ is the wavolongth of the radialion used), it was found that the Qp values varied almost liuearly with the concentration 01 $LnF_3$. The emissiou spect1.a of $Ce^{3-}$-containing fluoride glasses nnder 273 nm excitation had a peak maximum at ea. 300 nm $(Ce^{3+}$ 5d-4f- transition). The maximal intensity of the fluorescence was observed when the $CeF_3$, content was extremely low (ca. 1 mol%j. DTA measurement revealed tbat these fluoride glasses had two crystallization temperatures. In $56ZrF_4. 34BaF_2. 4NF_3. (6-x)LaF_3 .xNdF_3$ glasses, the actmation energies of crystallization obtained from a Kssinger plot were 1.7 and 5.0 eV for the glass with x=2, and 1.9 and 5.6 eV for the glass with x=4.

• Journal of Integrative Natural Science
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• v.8 no.1
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• pp.30-39
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• 2015

The crystal structure of the potential active 2-amino-4-(4-hydroxy-3-methoxyphenyl)-7, 9-dimethyl-5-oxo-4, 5, 6, 7-tetrahydropyrano [2, 3-d] pyrazolo [3, 4-b] pyridine-3-carbonitrile ($C_{21}H_{22}N_5O_6S$) has been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the monoclinic space group P-1 with unit cell dimension a=8.1201(9)${\AA}$, b=12.2684(4)${\AA}$ and c=12.387(2)${\AA}$ [${\alpha}=69.573^{\circ}$, ${\beta}=12.168^{\circ}$ and ${\gamma}=76.060^{\circ}$]. In the structure the pyrazole, pyridine and pyran are almost coplanar each other. The crystal packing is stabilized by intermolecular C-H...O and N-H... O hydrogen bond interaction.

• Korean Journal of Materials Research
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• v.19 no.4
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• pp.186-191
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• 2009

Thermoelectric power and resistivity are measured for the perovskite $LaNi_{1-x}Ti_xO_3$ ($x{\leq}0.5$) in the temperature range 77 K - 300 K. The measured thermoelectric power of $LaNi_{1-x}Ti_xO_3$ ($x{\leq}0.5$) increases linearly with temperature and is represented by A + BT. The x = 0.1 sample showed metallic behavior, the x = 0.3 showed metal and insulating transition around 150 K, and x = 0.5 showed insulating behavior the over the whole temperature range. The electrical resistivity of x = 0.1 shows linear temperature dependence over the whole temperature range and $T^2$ dependence. On the other hand, the electrical resistivity of x = 0.3 shows a linear relation between $ln{\rho}$ and $T^{-1/4}$ (variable range hopping mechanism) in the range of 77 K to 150 K. For x = 0.5, the temperature dependence of resistivity is characteristic of insulating materials; the resistivity data was fitted to an exponential law, such as ln(${\rho}/T$) and $T^{-1}$, which is usually attributed to a small polaron hopping mechanism. These experimental results are interpreted in terms of the spin polaron (x = 0.1) and variable range hopping (x = 0.3) or small polaron hopping (x = 0.5) of an almost localized $Ni^{3+}$ 3d polaron.

• Journal of the Optical Society of Korea
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• v.18 no.5
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• pp.500-506
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• 2014

A new 3-D reconstruction algorithm for the human face is proposed using the derivative Moir$\acute{e}$ topography which ensures fast and robust reconstruction even for rough surfaces. The Moir$\acute{e}$ interference fringe pattern is initially obtained through the projection Moir$\acute{e}$ topography based on phase shifting, and then differentiated to provide a full unwrapped phase map for a human face. $2{\pi}$ ambiguity, which has been a chronically unsolved problem with Moir$\acute{e}$ topography, is successfully surmounted by differentiating the Moir$\acute{e}$ fringe patterns both in x- and y-directions when the object is located in the x-y plane. A real human face is used for verifying the proposed derivative Moir$\acute{e}$ topography. A human face of 4 different phase-shifted images taken in the fixed plane is almost fully reconstructed in 3-D format in 0.1 mm lateral resolution.

• Korean Journal of Poultry Science
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• v.3 no.1
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• pp.11-18
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• 1976

Metabolizable energy (M.E.) values of 12 U.S. feedstuffs and 10 Korean feed ingredients for poultry were determined both by the total collection method and by the chromic oxide indicator method. It was found that M.E. values of most poultry feedstuffs can be measured accurately by either method. Limitation of feed intake to almost maintenance level(approximately 60% of ad libitum) did not increase or decrease the M.E. value of the feeds. An attempt was made to establish a prediction equation to estimate the M.E. values based on the apparent metabolizability of dry matter (D.M.) in the feedstuffs. The results indicated that linear relationships do exist between D. M. metabolizability and M.E. values of carbohydrate-rich feedstuffs (grains and their by-products) or protein-rich feed ingredients (oil seed meals and animal protein feeds) or lipid-rich feeds (fats and oils) as follows: The prediction equation for carbohydrate-rich feedstuffs was Y = 0.0947x - 3.498 ($r^2\;=\;0.99$, Sy.x = 0.015); for protein-rich feed ingredients. it was Y = 0.1234x - 4.898 ($r^2\;=\;0.99$, Sy.x = 0.027); and for lipid-rich feedstuffs it was Y = 0.0844x + 0.774 ($r^2\;=\;0.99$, Sy.x = 0.032). where x = metabolizability of dry matter of feeds in %, and Y=metabolizable energy values in kcal./g. The errors attached to these estimations were relatively small. Thus these prediction equations may be very useful for estimation of the M.E. values from D.M. apparent metaboiizability of feeds, especially in areas of the world where calorimetry is not possible.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2002.02a
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• pp.346-350
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• 2002

The effect of Ca-doping on the superconducting properties of Nd-Ba-Cu-O bulk superconductors, fabricated by the oxygen-controlled melt growth process, has been systematically investigated. Various c-axis textured bulk samples were grown using precursors with the nominal compositions of N $d_{1.8-x}$C $a_{x}$B $a_{2.4}$C $u_{3.4}$ $O_{y}$ (x = 0.00, 0.02, 0.05, 0.10, 0.15) in a reduced oxygen atmosphere of 1% $O_2$ in Ar. Magnetization measurements revealed that the critical temperatures( $T_{c}$) were almost linearly depressed from 95K to 86K with increasing the Ca dopant from x = 0.0 to 0.15, respectively, and thus critical current densities( $J_{c}$) at 77K and for H//c-axis of specimens were gradually degraded with increasing x. Compositional analyses revealed that although the amounts of the Ca dopant both in NdB $a_2$C $u_3$ $O_{y}$(Nd123) and N $d_4$B $a_2$C $u_2$ $O_{10}$(Nd422) were increased with increasing x, only less than half of the initial Ca compositions were detected in melt-grown Ca-doped Nd-Ba-Cu-O bulk crystals. The supression of $T_{c}$ is attributed to an increased Nd substitution for the Ba site in the Nd123 superconducting matrix with increasing the amount of the Ca dopant.t.opant.t.t.t.t.t.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.5
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• pp.336-343
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• 2018

We herein present the design and fabrication of a Rx core chip operating in the X-band (10.5~13 GHz) using Win's commercial $0.25-{\mu}m$ GaAs pHEMT process technology. The X-band core chip comprises a low-noise amplifier, a four-bit phase shifter, and a serial-to-parallel data converter. The size is $1.75mm{\times}1.75mm$, which is the state-of-the-art size. The gain and noise figure are more than 10 dB but less than 2 dB, and both the input and output return losses are less than 10 dB. The RMS phase error is less than $5^{\circ}$, and the P1dB is 2 dBm at 12.5 GHz, the performance of which is equivalent to other GaAs core chips. The fabricated core chip was packaged in a QFN package type with a size of $3mm{\times}3mm$ for the convenience of assembly. We confirmed that the performance of the packaged core chip was almost the same as that of the chip itself.