• 대한수학회지
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• 제34권2호
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• pp.279-284
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• 1997

Let L/F be a finite separable extension of Henselian valued fields with same residue fields $\overline{L} = \overline{F}$. Let D be an inertially split division algebra over L, and let $^cD$ be the underlying division algebra of the corestriction $cor_{L/F} (D)$ of D. We show that the index $ind(^cD) of ^cD$ divides $[Z(\overline{D}) : Z(\overline {^cD})] \cdot ind(D), where Z(\overline{D})$ is the center of the residue division ring $\overline{D}$.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제13권1호
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• pp.49-61
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• 2009

In this paper some attempts have been made: (a) To identify all the elementary minor concepts of the Highest Common Factor (H.C.F.) and the Lowest Common Multiple (L.C.M.), and (b) To find the sequential order of these elementary concepts. Total 385 elementary minor concepts have been identified and sequenced.

• 한국육종학회지
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• 제41권4호
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• pp.463-467
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• 2009

Allium 속 근연종인 파와 양파간 종간교잡을 이용하여 양파로부터 새로운 형질을 도입하는 과정에서 유래되는 종간교잡 F1과 여교잡 세대들의 게놈크기의 변화를 flow cytometry를 이용하여 측정한 결과 다음과 같은 결과를 얻었다. 1. 양파와 파의 종간교잡 F1의 식물학적 특성은 양친의 중간형을 보였으나 여교잡이 진전됨에 따라 반복친인 파의 표현형이 우세하였다. flow cytometry를 이용하여 2C nuclear DNA content을 측정한 결과 $F_1$은 양친에 비해 오히려 증가하였으나 여교잡이 진행됨에 따라 급속히 감소하여 $BC_2F_1$에서는 반복친과 비슷한 수준으로 감소하였다. 여교잡세대의 자식인 $BC_1F_2$은 반복친과 비슷한 $23.1{\pm}1.0pg$으로 측정되었으나 $BC_2F_2$는 $22.9{\pm}0.4pg$으로 반복친의 2C nuclear DNA content인 $23.2{\pm}0.2pg$ 보다 오히려 감소하였다.

• 대한가정학회지
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• 제20권4호
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• pp.1-12
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• 1982

This study was to investigate the changes of shape of the lower limb surface, the rate of the measurement of expansion and contraction and correlation coefficient between variables caused by hip joint and knee joint movements. The results of the investigation are as follows; 1. According to the development figure of shell when the leg was raised $45^{\circ}$forward($M_{2}$), total length of F.L shortened while B.L lengthened. This result is contarary to $M_{3}$raising the leg $15^{\circ}$ backward. In both $M_{2}$, $M_{3}$movements, the rate of expansion and contraction to the course direction was insignificant. When hip joint was bent $15^{\circ}$ with knee joint $120^{\circ}$bent ($M_{4}$) and hip joint was bent $30^{\circ}$ with knee joint $90^{\circ}$ bent($M_{5}$), upper section of back hip expanded while the front hip section contracted slightly. In the Movement of sitting on the chair($M_{6}$), abdomen, front hip section and upper thight section contracted to the wale direction remarkably while the back hip section expanded conspicuously. 2. According to the rate of expansion and contraction of skin (surface) by the somatometry. In $M_{2}$, C.F.L. upper and middle thight girth contracted and B.L, C.L, L.L expanded. This fact is contarary to M3. In M4, M5, C.F.L showed remarkable contraction and C.B.L expanded remarkably. In $M_{6}$, C.B.L contracted most of all the items measured and knee girth, F.L, L.L, C.B.L, hip girth expanded conspicuously. 3. According to the correlation coefficient between variables. In various movements, the correlation among girth items commonly showed a high or middle grade, the correlation among length items also commonly showed a low grade and that girth and length items showed a very low grade commonly. Waist girth, hip grith, F.L, B.L, L.L items showed that there were significant correlation.

• Journal of applied mathematics & informatics
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• 제16권1_2호
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• pp.461-468
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• 2004

Let W(z) be a power series with operator coefficients such that multiplication by W(z) is contractive in C(z). The overlapping space $L(\varphi)$ of H(W) in C(z) is a Herglotz space with Herglotz function $\varphi(z)$ which satisfies $\varphi(z)+\varphi^＊(z^{-1})=2[1-W^{*}(z^{-1})W(z)]$. The identity ${}_{L(\varphi)}={-}_{H(W)}$ holds for every f(z) in $L(\varphi)$ and for every vector c.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2003년도 추계 학술대회논문집
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• pp.89-94
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• 2003

A successful store separation analysis tool, MSAP(Multi-body Separation Analysis Program) has been applied to F/A-18C/JDAM CFD Challenge II. The challenge was devised to challenge CFD community to use CFD methodologies to predict and match the trajectory of a JDAM MK-84 separating from F/A-l8C. Trajectory simulations for two flight conditions were performed. Comparison between computed and measured flight trajectories for both conditions shows a good agreement.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제15권4호
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• pp.319-328
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• 2011

Let $\mathbf{c}=\{c_n\}_{n{\in}\mathbb{Z}}\in{\ell}^1(\mathbb{Z})$ and $\{f_n\}_{n{\in}\mathbb{Z}}$ be a frame (Riesz basis, respectively) of $L^2(\mathbb{R})$. We obtain necessary and sufficient conditions of $\mathbf{c}$ under which $\{\mathbf{c}{\ast}_{\lambda}f_n\}_{n{\in}\mathbb{Z}}$ becomes a frame (Riesz basis, respectively) of $L^2(\mathbb{R})$, where ${\lambda}$ > 0 and $(\mathbf{c}{\ast}_{\lambda}f)(t)\;:=\;{\sum}_{n{\in}\mathbb{Z}}c_nf(t-n{\lambda})$. When $\{\mathbf{c}{\ast}_{\lambda}f_n\}_{n{\in}\mathbb{Z}}$ becomes a frame of $L^2(\mathbb{R})$, we present its frame operator and the canonical dual frame in a simple form. Some interesting examples are included.

• 대한수학회지
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• 제45권4호
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• pp.977-991
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• 2008

We characterize the boundedness and compactness of the weighted composition operator $uC_{\psi}$ from the general function space F(p, q, s) into the logarithmic Bloch space ${\beta}_L$ on the unit disk. Some necessary and sufficient conditions are given for which $uC_{\psi}$ is a bounded or a compact operator from F(p,q,s), $F_0$(p,q,s) into ${\beta}_L$, ${\beta}_L^0$ respectively.

• 한국재료학회지
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• 제20권4호
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• pp.194-198
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• 2010

Cubic boron nitride (c-BN) is a promising material for use in many potential applications because of its outstanding physical properties such as high thermal stability, high abrasive wear resistance, and super hardness. Even though 316L austenitic stainless steel (STS) has poor wear resistance causing it to be toxic in the body due to wear and material chips, 316L STS has been used for implant biomaterials in orthopedics due to its good corrosion resistance and mechanical properties. Therefore, in the present study, c-BN films with a $B_4C$ layer were applied to a 316L STS specimen in order to improve its wear resistance. The deposition of the c-BN films was performed using an r.f. (13.56 MHz) magnetron sputtering system with a $B_4C$ target. The coating layers were characterized using XPS and SEM, and the mechanical properties were investigated using a nanoindenter. The friction coefficient of the c-BN coated 316L STS steel was obtained using a pin-on-disk according to the ASTM G163-99. The thickness of the obtained c-BN and $B_4C$ were about 220 nm and 630 nm, respectively. The high resolution XPS spectra analysis of B1s and N1s revealed that the c-BN film was mainly composed of $sp^3$ BN bonds. The hardness and elastic modulus of the c-BN measured by the nanoindenter were 46.8 GPa and 345.7 GPa, respectively. The friction coefficient of the c-BN coated 316L STS was decreased from 3.5 to 1.6. The wear property of the c-BN coated 316L STS was enhanced by a factor of two.

• 대한수학회보
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• 제40권3호
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• pp.457-464
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• 2003

Given a Riemannian manifold (M, $\alpha$) with an almost Hermitian structure f and a non-vanishing covariant vector field b, consider the generalized Randers metric $L\;=\;{\alpha}+{\beta}$, where $\beta$ is a special singular Riemannian metric defined by b and f. This metric L is called an (a, b, f)-metric. We compute the inverse and the determinant of the fundamental tensor ($g_{ij}$) of an (a, b, f)-metric. Then we determine the maximal domain D of $TM{\backslash}O$ for an (a, b, f)-manifold where a y-local Finsler structure L is defined. And then we show that any (a, b, f)-manifold is quasi-C-reducible and find a condition under which an (a, b, f)-manifold is C-reducible.