• Title/Summary/Keyword: X-means

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Pretilt control of nematic liquid crystal by deposition of $SiO_x$ film (비정질 $SiO_x$ 박막을 이용한 nematic 액정의 선경사각 제어)

  • Park, Jeong-Hun;Son, Pil-Guk;Cha, Seong-Su;Kim, Jae-Chang;Yun, Tae-Hun
    • Proceedings of the Optical Society of Korea Conference
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    • 2006.07a
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    • pp.91-92
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    • 2006
  • Liquid crystal (LC) alignment on $a-SiO_x$ thin film was investigated by means of X-ray photoemission spectroscopy and optical transmittance as we varied the deposition temperature and the target-to-substrate distance. LC molecules can be aligned vertically on $a-SiO_x$ film when the stoichiometric parameter x of $a-SiO_x$ is smaller than 1.56, but they can be aligned homogeneously when x is larger than 1.56. We also found that whether liquid crystals can be aligned vertically or homogeneously on $a-SiO_x$ film can be predicted simply by measuring the change in optical transmittance by deposition of $a-SiO_x$ thin film layers.

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Bayesian Test for the Equality of Gamma Means

  • Kang, Sang-Gil
    • Journal of the Korean Data and Information Science Society
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    • v.17 no.4
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    • pp.1413-1425
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    • 2006
  • When X and Y have independent gamma distributions, we develop a Bayesian procedure for testing the equality of two gamma means. The reference prior is derived. Using the derived reference prior, we propose a Bayesian test procedure for the equality of two gamma means using fractional Bayes factor and intrinsic Bayes factor. Simulation study and a real data example are provided.

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A Comparison of the Rudin-Osher-Fatemi Total Variation model and the Nonlocal Means Algorithm

  • Adiya, Enkhbolor;Choi, Heung-Kook
    • Proceedings of the Korea Multimedia Society Conference
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    • 2012.05a
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    • pp.6-9
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    • 2012
  • In this study, we compare two image denoising methods which are the Rudin-Osher-Fatemi total variation (TV) model and the nonlocal means (NLM) algorithm on medical images. To evaluate those methods, we used two well known measuring metrics. The methods are tested with a CT image, one X-Ray image, and three MRI images. Experimental result shows that the NML algorithm can give better results than the ROF TV model, but computational complexity is high.

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A NOTE ON REAL QUATERNION

  • Hwang, Chul Ju
    • Korean Journal of Mathematics
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    • v.17 no.3
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    • pp.245-248
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    • 2009
  • We consider pm-ring with the property such that every prime ideal is contained in only one maximal ideal. Orsatti[4] characterized pm-rings by means of the retraction. Contessa[1] found algebraic condition, by using that direct product of pm-rings is a pm-ring. We show that C(X, H) and C(X, C) are pm-rings and we extend a quasi pm-domain.

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Dispersion of SmxCe1-xO2-2/x Nanoparticles which is Synthesized by Hydrothermal Process in Aqueous System (수열합성법으로 합성된 나노 SmxCe1-xO2-2/x 분말의 수계 분산)

  • Bae Dong-Sik;Kim Eun-Jung;Han Kyong-Sop
    • Korean Journal of Materials Research
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    • v.15 no.2
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    • pp.112-114
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    • 2005
  • Dispersion stability of the $Sm_xCe_{1-x}O_{2-2/x}$ nanoparticles, which was produced by hydrothermal process, was studied in aqueous suspension using ESA (Eletrokinetic Sonic Amplitude). The average particle size of the synthesized $Sm_xCe_{1-x}O_{2-2/x}$ at nanoparticles was about $5{\pm}2nm$. The dispersion and rheological behavior of the $Sm_xCe_{1-x}O_{2-2/x}$ nanoparticles aqueous suspension was investigated using $NH_4OH\;and\;HNO_3$ as a disperse agent. The colloidal stability of aqueous suspensions with $Sm_xCe_{1-x}O_{2-2/x}$ nanoparticles at different pH values has been investigated by means of zeta potential, average particle size, and the distribution of synthesized $Sm_xCe_{1-x}O_{2-2/x}$ nanoparticles. The isoelectric point of the $Sm_xCe_{1-x}O_{2-2/x}$ nanoparticles was at pH around 11 and the value of zeta potential was at its maximum near pH 6.5.

Study on the analysis of disproportionate data and hypothesis testing (불균형 자료 분석과 가설 검정에 관한 연구)

  • 장석환;송규문;김장한
    • The Korean Journal of Applied Statistics
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    • v.5 no.2
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    • pp.243-254
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    • 1992
  • In the present study two sets of unbalanced two-way cross-classification data with and without empty cell(s) were used to evaluate empirically the various sums of squares in the analysis of variance table. Searle(1977) and Searle et.al.(1981) developed a method of computing R($\alpha$\mid$\mu, \beta$) and R($\beta$\mid$\mu, \alpha$) by the use of partitioned matrix of X'X for the model of no interaction, interchanging the columns of X in order of $\alpha, \mu, \beta$ and accordingly the elements in b. An alternative way of computing R($\alpha$\mid$\mu, \beta$), R($\beta$\mid$\mu, \alpha$) and R($\gamma$\mid$\mu, \alpha, \beta$) without interchanging the columns of X has been found by means of,$(X'X)^-$ derived, using $W_2 = Z_2Z_2-Z_2Z_1(Z_1Z_1)^-Z_1Z_2$. It is true that $R(\alpha$\mid$\mu,\beta,\gamma)\Sigma = SSA_W and R(\beta$\mid$\mu,\alpha,\gamma)\Sigma = SSB_W$ where $SSA_W$ and means analysis and $R(\gamma$\mid$\mu,\alpha,\beta) = R(\gamma$\mid$\mu,\alpha,\beta)\Sigma$ for the data without empty cell, but not for the data with empty cell(s). It is also noticed that for the datd with empty cells under W - restrictions $R(\alpha$\mid$\mu,\beta,\gamma)_W = R(\mu,\alpha,\beta,\gamma)_W - R(\mu,\alpha,\beta,\gamma)_W = R(\alpha$\mid$\mu) and R(\beta$\mid$\mu,\alpha,\gamma)_W = R(\mu,\alpha,\beta,\gamma)_W - R(\mu,\alpha,\beta,\gamma)_W = R(\beta$\mid$\mu) but R(\gamma$\mid$\mu,\alpha,\beta)_W = R(\mu,\alpha,\beta,\gamma)_W - R(\mu,\alpha,\beta,\gamma)_W \neq R(\gamma$\mid$\mu,\alpha,\beta)$. The hypotheses $H_o : K' b = 0$ commonly tested were examined in the relation with the corresponding sums of squares for $R(\alpha$\mid$\mu), R(\beta$\mid$\mu), R(\alpha$\mid$\mu,\beta), R(\beta$\mid$\mu,\alpha), R(\alpha$\mid$\mu,\beta,\gamma), R(\beta$\mid$\mu,\alpha,\gamma), and R(\gamma$\mid$\mu,\alpha,\beta)$ under the restrictions.

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NONLINEAR DIFFERENTIAL EQUATIONS OF SECOND ORDER IN A HILBERT SPACE

  • Kim, RakJoong
    • Korean Journal of Mathematics
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    • v.16 no.1
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    • pp.91-101
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    • 2008
  • Let H be a Hilbert space. Assume that $0{\leq}{\alpha}$, ${\beta}{\leq}1$ and r(t) > 0 in I = [0, T]. By means of the fixed point theorem of Leray-Schauder type the existence principles of solutions for two point boundary value problems of the form $\array{(r(t)x^{\prime}(t))^{\prime}+f(t,x(t),r(t)x^{\prime}(t))=0,\;t{\in}I\\x(0)=x(T)=0}$ are established where f satisfies for positive constants a, b and c ${\mid}{f(t,x,y){\mid}{\leq}a{\mid}x{\mid}^{\alpha}+b{\mid}y{\mid}^{\beta}+c\;\;for\;all(t,x,y){\in}I{\times}H{\times}H$.

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Preparation of Textured Grourth YbBaCuO Superconductor (YbBaCuO 초전도체의 텍스쳐 조직 성장)

  • 소대화;번점국
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.04a
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    • pp.49-53
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    • 1997
  • In this paper, YbBa$_{2}$Cu$_{3}$O$_{x}$ superconductor was sintered by means of conventional solid reaction and the textured YbBa$_{2}$Cu$_{3}$O$_{x}$ was prepared by the Melted-Condensed Process in which SmBa$_{2}$Cu$_{3}$O$_{x}$ crystal was used as seed crystal to introduce the YbBa$_{2}$Cu$_{3}$O$_{x}$ crystal growth. The texture of YbBa$_{2}$Cu$_{3}$O$_{x}$ was examined by X-ray diffraction, and the fracture of YbBa$_{2}$Cu$_{3}$O$_{x}$ sample was observed by SEM, which proved the sample was well oriented. After oxygen absorption of the textured YbBa$_{2}$Cu$_{3}$O$_{x}$ sample, it's critical temperature was measureed to be 86K.eed to be 86K.

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Velocity Change of Magneto Surface Acoustic Wave (MSAW) in (Fe1-xCox)89Zr11 Amorphous Films (II) ((Fe1-xCox)89Zr11 비정질 자성막에서의 자기표면탄성파 속도변화(II))

  • Kim, Sang-Won
    • Korean Journal of Materials Research
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    • v.12 no.4
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    • pp.279-282
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    • 2002
  • The effect of field annealing on the velocity changes of magneto surface acoustic wave (MSAW) devices has been investigated for deposited $(Fe_{1-x}Co_x)_{89}Zr_{11}$ (x = 0~1.0) amorphous films. By means of two step field annealing at $195^{\circ}C$ for 10 minute in the magnetic field of 130 Oe, the MSAW device with x=0.4 film among the devices showed the superior velocity change of 0.1 %. This gigantic value was obtained in the DC bias field of 40 Oe at the exciting frequency of 8.7 MHz. It was confirmed that such behavior was due to the variation of differential permeability caused by an optimal stress within the magnetic film.