• 약학회지
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• 제43권3호
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• pp.378-384
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• 1999

Retinoic acid (RA) and dibutyryl cyclic AMP (dbcAMP) induce the differentiation of the multipotent embryonic carcinoma cell line, F9 cells, into parietal endoderm like cell. The F9 cells are highly proliferative doubling approximately 12 hourse. S Phase is predominant, lasting 10 hours and G2/M phase occupies most of the remaining cycle (2 hours) and G1 phase is nearly non-existent. In this study, we showed the effect of RA and dbcAMPon the cell cycle associated molecules (especially around G1 phase) during F9 cell differentiation. Differentiation of F9 cells was induced by the combined addition of RA ($10^{-7}M$) and dbcAMP (0.5mM), and cells were harvested daily up to 4 days. Flow cytometric analysis showed the prolongation of G1 phase around 30 hours after induction. Western blot analysis revealed that the amount of cyclin D1 and cdk2 were increased at day 4. However, histone H1 kinase activity of cdk2 was decreased. These data strongly suggest that RA and dbcAMP induce the growth arrest of F9 cells at G1 phase by decreasing the activity of cdk2, although they have increased the protein contents of cyclin D1 and cdk2. The reason for the discrepancy between the H1 kinase activity and protein contents are not clear yet.

• 대한수학회지
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• 제45권3호
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• pp.597-609
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• 2008

In this paper, we will consider certain amalgamated free product structure in crossed product algebras. Let M be a von Neumann algebra acting on a Hilbert space Hand G, a group and let ${\alpha}$ : G${\rightarrow}$ AutM be an action of G on M, where AutM is the group of all automorphisms on M. Then the crossed product $\mathbb{M}=M{\times}{\alpha}$ G of M and G with respect to ${\alpha}$ is a von Neumann algebra acting on $H{\bigotimes}{\iota}^2(G)$, generated by M and $(u_g)_g{\in}G$, where $u_g$ is the unitary representation of g on ${\iota}^2(G)$. We show that $M{\times}{\alpha}(G_1\;*\;G_2)=(M\;{\times}{\alpha}\;G_1)\;*_M\;(M\;{\times}{\alpha}\;G_2)$. We compute moments and cumulants of operators in $\mathbb{M}$. By doing that, we can verify that there is a close relation between Group Freeness and Amalgamated Freeness under the crossed product. As an application, we can show that if $F_N$ is the free group with N-generators, then the crossed product algebra $L_M(F_n){\equiv}M\;{\times}{\alpha}\;F_n$ satisfies that $$L_M(F_n)=L_M(F_{{\kappa}1})\;*_M\;L_M(F_{{\kappa}2})$$, whenerver $n={\kappa}_1+{\kappa}_2\;for\;n,\;{\kappa}_1,\;{\kappa}_2{\in}\mathbb{N}$.

• 대한수학회논문집
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• 제10권1호
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• pp.235-249
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• 1995

Let K be a bounded linear operator from Hilbert space $H_1$ into Hilbert space $H_2$. When numerically solving the first kind equation Kf = g, one usually picks n orthonormal functions $\phi_1, \phi_2,...,\phi_n$ in $H_1$ which depend on the numerical method and on the problem, see Varah [12] for more details. Then one findes the unique minimum norm element $f_M \in M$ that satisfies $\Vert K f_M - g \Vert = inf {\Vert K f - g \Vert : f \in M}$, where M is the linear span of $\phi_1, \phi_2,...,\phi_n$. Such a solution $f_M \in M$ is called the M-solution of K f = g. Some methods for finding the M-solution of K f = g were proposed by Banks [2] and Marti [9,10]. See [5,6,8] for convergence results comparing the M-solution of K f = g with $f_0$, the least squares solution of minimum norm (LSSMN) of K f = g.

• East Asian mathematical journal
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• 제21권1호
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• pp.61-64
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• 2005

Let R be a commutative ring with identity, and let $f,\;g_i(i=1,\;\ldots,\;n),\;g_{\alpha}(\alpha{\in}S)$ be elements of R. We show that the following statements are equivalent; (i) $X_f{\subseteq}{\cup}_{\alpha{\in}S}X_{g\alpha}$ only if $X_f{\subseteq}X_{g\alpha}$ for some $\alpha{\in}S$, (ii) $V(f){\subseteq}{\cup}_{\alpha{\in}S}V(g_{\alpha})$ only if $V(f){\subseteq}V(g_{\alpha})$ for some $\alpha{\in}S$, (iii) $V(f){\subseteq}{\cup}^n_{i=1}V(g_i)$ only if $V(f){\subseteq}V(g_i)$ for some i, (iv) Spec(R) is linearly ordered under inclusion.

• 정보처리학회논문지A
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• 제18A권6호
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• pp.225-232
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• 2011

Restricted Hypercube-Like(RHL) 그래프는 교차큐브, 뫼비우스큐브, 엠큐브, 꼬인큐브, 지역꼬인큐브, 다중꼬인큐브, 일반꼬인큐브와 같이 유용한 상호연결망들을 광범위하게 포함하는 그래프군이다. 본 논문에서는 $m{\geq}4$ 인 m-차원 RHL 그래프 G에 대해서 임의의 에지 집합 $F{\subset}E(G)$, ${\mid}F{\mid}{\leq}m-2$, 가 고장일 때, 고장 에지들을 제거한 그래프 $G{\setminus}F$는 임의의 서로 다른 두 정점 s와 t에 대해서 dist(s, V(F))${\neq}1$ 이거나 dist(t, V(F))${\neq}1$이면 해밀톤 경로가 있음을 보인다. V(F)는 F에 속하는 에지들의 양 끝점들의 집합이고 dist(v, V(F))는 정점 v와 집합 V(F)의 정점들 간의 최소 거리이다.

• 한국정보과학회논문지:시스템및이론
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• 제31권1_2호
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• pp.86-94
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• 2004

이 논문에서는 재귀원형군 $ G(2^m, 4), m{\geq}3$은 고장인 요소의 수가 m-2개 이하일 때, 임의의 1, 4 ${\leq}1{\leq}2^m-f_v$에 대하여 길이 1인 고장 없는 사이클을 가짐을 보인다. 여기서, f$_{v}$ 는 고장 정점의 수이다. 이를 위하여, ｜F｜$\leq$k인 임의의 고장 요소 집합 F에 대해서 G-F가 임의의 두 정점을 잇는 길이가 해밀톤 경로보다 하나 작은 경로를 가질 때, G를 k-고장 하이포해밀톤 연결된 그래프라고 정의하고, $ G(2^m, 4), m{\geq}3$은 m-3-고장 하이포해밀톤 연결된 그래프임을 보인다.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제9권1호
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• pp.1-7
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• 2002

For A bounded subset G of a metric Space (X,d) and $\chi \in X$, let $f_{G}$ be the real-valued function on X defined by $f_{G}$($\chi$)=sup{$d (\chi, g)\in:G$}, and $F(G,\chi)$={$z \in X:sup_{g \in G}d(g,z)=sup_{g \in G}d(g,\chi)+d(\chi,z)$}. In this paper we discuss some properties of the map $f_G$ and of the set $ F(G, \chi)$ in convex metric spaces. A sufficient condition for an element of a convex metric space X to lie in $ F(G, \chi)$ is also given in this pope.

• 대한수학회보
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• 제44권4호
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• pp.623-629
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• 2007

In this paper, we study the uniqueness of entire functions and prove the following result: Let f and g be two nonconstant entire functions, n, m be positive integers. If $f^n(f^m-1)f#\;and\;g^n(g^m-1)g#$ share 1 IM and n>4m+11, then $f{\equiv}g$. The result improves the result of Fang-Fang.

• Journal of Microbiology and Biotechnology
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• 제26권5호
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• pp.959-966
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• 2016

Chlorophyll synthase (ChlG) and bacteriochlorophyll synthase (BchG) have a high degree of substrate specificity. The BchG mutant of Rhodobacter sphaeroides, BG1 strain, is photosynthetically incompetent. When BG1 harboring chlG of Synechocystis sp. PCC 6803 was cultured photoheterotrophically, colonies arose at a frequency of approximately 10^-8. All the suppressor mutants were determined to have the same mutational change, ChlG_I44F. The mutated enzyme ChlG_I44F showed BchG activity. Remarkably, BchG_F28I, which has the substitution of F at the corresponding 28^th residue to I, showed ChlG activity. The K_m values of ChlG_I44F and BchG_F28I for their original substrates, chlorophyllide (Chlide) a and bacteriochlorophyllide (Bchlide) a, respectively, were not affected by the mutations, but the K_m values of ChlG_I44F and BchG_F28I for the new substrates Bchlide a and Chlide a, respectively, were more than 10-fold larger than those for their original substrates, suggesting the lower affinities for new substrates. Taken together, I44 and F28 are important for the substrate specificities of ChlG and BchG, respectively. The BchG activity of ChlG_I44F and the ChlG activity of BchG_F28I further suggest that ChlG and BchG are evolutionarily related enzymes.

• Kyungpook Mathematical Journal
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• 제45권3호
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• pp.395-404
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• 2005

Let α be a complex number with 𝕽α > 0. Let the functions f and g be analytic in the unit disc E = {z : |z| < 1} and normalized by the conditions f(0) = g(0) = 0, f'(0) = g'(0) = 1. In the present article, we study the differential subordinations of the forms $${\alpha}{\frac{z^2f^{{\prime}{\prime}}(z)}{f(z)}}+{\frac{zf^{\prime}(z)}{f(z)}}{\prec}{\alpha}{\frac{z^2g^{{\prime}{\prime}}(z)}{g(z)}}+{\frac{zg^{\prime}(z)}{g(z)}},\;z{\in}E,$$ and $${\frac{z^2f^{{\prime}{\prime}}(z)}{f(z)}}{\prec}{\frac{z^2g^{{\prime}{\prime}}(z)}{g(z)}},\;z{\in}E.$$ As consequences, we obtain a number of sufficient conditions for star likeness of analytic maps in the unit disc. Here, the symbol ' ${\prec}$ ' stands for subordination