• Title/Summary/Keyword: k-$\omega$

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Synthesis of Monomers for Polyamide-type TPEs from Oleic Acid (천연 올레인산 기반 폴리아미드계 TPEs 단량체 합성)

  • Koh, Moo-Hyun;Kim, Hyun Su;Kim, Hyeonjeong;Shin, Nara;Yoo, Dongwon;Kim, Young Gyu
    • Elastomers and Composites
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    • v.48 no.1
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    • pp.24-29
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    • 2013
  • We have developed the synthetic processes for the monomers of polyamide-type TPEs (thermoplastic elastomers, TPAEs) obtained from vegetable oil. TPAEs have several superior physical properties to those of thermoplastic elastomers (TPEs). From the common starting material, oleic acid, which is commonly found in various vegetable oils, we have synthesized three ${\omega}$-amino acid monomers ($C_9$, $C_{10}$ and $C_{11}$ ${\omega}$-amino acid) and three ${\alpha}$, ${\omega}$-dicarboxylic acids($C_9$, $C_{10}$ and $C_{11}$ ${\alpha}$, ${\omega}$-dicarboxylic acid) for TPAEs in good yields.

Identification of ${\omega}$-Aminotransferase from Caulobacter crescentus and Sitedirected Mutagenesis to Broaden Substrate Specificity

  • Hwang, Bum-Yeol;Ko, Seung-Hyun;Park, Hyung-Yeon;Seo, Joo-Hyun;Lee, Bon-Su;Kim, Byung-Gee
    • Journal of Microbiology and Biotechnology
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    • v.18 no.1
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    • pp.48-54
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    • 2008
  • A putative ${\omega}$-aminotransferase gene, cc3143 (aptA), from Caulobacter crescentus was screened by bioinformatical tools and overexpressed in E. coli, and the substrate specificity of the ${\omega}$-aminotransferase was investigated. AptA showed high activity for short-chain ${\beta}$-amino acids. It showed the highest activity for 3-amino-n-butyric acid. It showed higher activity toward aromatic amines than aliphatic amines. The 3D model of the ${\omega}$-aminotransferase was constructed by homology modeling using a dialkylglycine decarboxylase (PDB ID: 1DGE) as a template. Then, the ${\omega}$-aminotransferase was rationally redesigned to increase the activity for 3-amino-3-phenylpropionic acid. The mutants N285A and V227G increased the relative activity for 3-amino-3-phenylpropionic acid to 3-amino-n-butyric acid by 11-fold and 3-fold, respectively, over that of wild type.

ESTIMATES OF THE BERGMAN KERNEL FUNCTION ON PSEUDOCONVEX DOMAINS WITH COMPARABLE LEVI FORM

  • Cho, Sang-Hyun
    • Journal of the Korean Mathematical Society
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    • v.39 no.3
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    • pp.425-437
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    • 2002
  • Let $\Omega$ be a smoothly bounded pseudoconvex domain in $C^{n}$ and let $z^{0}$ $\in$b$\Omega$ a point of finite type. We also assume that the Levi form of b$\Omega$ is comparable in a neighborhood of $z^{0}$ . Then we get precise estimates of the Bergman kernel function, $K_{\Omega}$(z, w), and its derivatives in a neighborhood of $z^{0}$ . .

AN ANALOGUE OF WIENER MEASURE AND ITS APPLICATIONS

  • Im, Man-Kyu;Ryu, Kun-Sik
    • Journal of the Korean Mathematical Society
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    • v.39 no.5
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    • pp.801-819
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    • 2002
  • In this note, we establish a translation theorem in an analogue of Wiener space (C[0,t],$\omega$$\phi$) and find formulas for the conditional $\omega$$\phi$-integral given by the condition X(x) = (x(to), x(t$_1$),…, x(t$_{n}$)) which is the generalization of Chang and Chang's results in 1984. Moreover, we prove a translation theorem for the conditional $\omega$$\phi$-integral.l.

NONTRIVIAL SOLUTIONS FOR AN ELLIPTIC SYSTEM

  • Nam, Hyewon;Lee, Seong Cheol
    • Korean Journal of Mathematics
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    • v.23 no.1
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    • pp.153-161
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    • 2015
  • In this work, we consider an elliptic system $$\left{\array {-{\Delta}u=au+bv+{\delta}_1u+-{\delta}_2u^-+f_1(x,u,v) && in\;{\Omega},\\-{\Delta}v=bu+cv+{\eta}_1v^+-{\eta}_2v^-+f_2(x,u,v) && in\;{\Omega},\\{\hfill{70}}u=v=0{\hfill{90}}on\;{\partial}{\Omega},}$$, where ${\Omega}{\subset}R^N$ be a bounded domain with smooth boundary. We prove that the system has at least two nontrivial solutions by applying linking theorem.

$L_q$ estimation on the least energy solutions

  • Pahk, Dae-Hyeon;Park, Sang-Don
    • Journal of the Korean Mathematical Society
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    • v.32 no.2
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    • pp.329-339
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    • 1995
  • Let us consider the Neumann problem for a quasilinear equation $$ (I_\varepsilon) {\varepsilon^m div($\mid$\nabla_u$\mid$^{m-2}\nabla_u) - u$\mid$u$\mid$^{m-2} + f(u) = 0 in \Omega {\frac{\partial\nu}{\partial u} = 0 on \partial\Omega. $$ where $1 < m < N, N \geq 2, \varepsilon > 0, \Omega$ is a smooth bounded domain in $R^n$ and $\nu$ is the unit outer normal vector to $\partial\Omega$.

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WEAK INVERSE SHADOWING AND Ω-STABILITY

  • Zhang, Yong;Choi, Taeyoung
    • Journal of the Chungcheong Mathematical Society
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    • v.17 no.2
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    • pp.137-145
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    • 2004
  • We give characterization of ${\Omega}$-stable diffeomorphisms via the notions of weak inverse shadowing. More precisely, it is proved that the $C^1$ interior of the set of diffeomorphisms with the weak inverse shadowing property with respect to the class $\mathcal{T}_h$ coincides with the set of ${\Omega}$-stable diffeomorphisms.

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LOWER HOUNDS ON THE HOLOMORPHIC SECTIONAL CURVATURE OF THE BERGMAN METRIC ON LOCALLY CONVEX DOMAINS IN $C^{n}$

  • Cho, Sang-Hyun;Lim, Jong-Chun
    • Bulletin of the Korean Mathematical Society
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    • v.37 no.1
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    • pp.127-134
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    • 2000
  • Let $\Omega$ be a bounded pseudoconvex domain in$C^{n}$ with smooth defining function r and let$z_0\; {\in}\; b{\Omega}$ be a point of finite type. We also assume that $\Omega$ is convex in a neighborhood of $z_0$. Then we prove that all the holomorphic sectional curvatures of the Bergman metric of $\Omega$ are bounded below by a negative constant near $z_0$.

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A NOTE ON ZEROS OF BOUNDED HOLOMORPHIC FUNCTIONS IN WEAKLY PSEUDOCONVEX DOMAINS IN ℂ2

  • Ha, Ly Kim
    • Bulletin of the Korean Mathematical Society
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    • v.54 no.3
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    • pp.993-1002
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    • 2017
  • Let ${\Omega}$ be a bounded, uniformly totally pseudoconvex domain in ${\mathbb{C}}^2$ with the smooth boundary b${\Omega}$. Assuming that ${\Omega}$ satisfies the negative ${\bar{\partial}}$ property. Let M be a positive, finite area divisor of ${\Omega}$. In this paper, we will prove that: if ${\Omega}$ admits a maximal type F and the ${\check{C}}eck$ cohomology class of the second order vanishes in ${\Omega}$, there is a bounded holomorphic function in ${\Omega}$ such that its zero set is M. The proof is based on the method given by Shaw [27].

DENSE SETS IN WEAK STRUCTURE AND MINIMAL STRUCTURE

  • Modak, Shyamapada
    • Communications of the Korean Mathematical Society
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    • v.28 no.3
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    • pp.589-596
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    • 2013
  • This paper is an attempt to study and introduce the notion of ${\omega}$-dense set in weak structures and the notion of m-dense set in minimal structures. We have also investigate the relationships between ${\omega}$-dense sets, $m$-dense sets, ${\sigma}({\omega})$ sets, ${\pi}({\omega})$ sets, $r({\omega})$ sets, ${\beta}({\omega})$ sets, m-semiopen sets and $m$-preopen sets. Further we give some representations of the above generalized sets in minimal structures as well as in weak structures.