• Title/Summary/Keyword: $L_k$-operator

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On the Weighted L1-convergence of Grünwald Interpolatory Operators

  • Wang, Jian Li;Zhou, Song Ping
    • Kyungpook Mathematical Journal
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    • v.46 no.1
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    • pp.111-118
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    • 2006
  • The present paper investigates the weighted $L^1$-convergence of Gr$\ddot{u}$nwald interpolatory operators based on the zeros of the second Chebyshev polynomials $U_n(x)=\frac{sin(n+1)\theta}{sin\theta}$. The approximation rate is sharp.

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M-IDEALS AND PROPERTY SU

  • Cho, Chong-Man;Roh, Woo-Suk
    • Bulletin of the Korean Mathematical Society
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    • v.38 no.4
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    • pp.663-668
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    • 2001
  • X and Y are Banach spaces for which K(X, Y), the space of compact operators from X to Y, is an M-ideal in L(X, Y), the space of bounded linear operators form X to Y. If Z is a closed subspace of Y such that L(X, Z) has property SU in L(X, Y) and d(T, K(X, Z)) = d(T, K(X, Y)) for all $T \in L(X, Z)$, then K(X, Z) is an M-ideal in L(X, Z) if and only if it has property SU is L(X, Z).

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Construction of Heat-Inducible Expression Vector of Corynebacterium glutamicum and C. ammoniagenes: Fusion of ${\lambda}$ Operator with Promoters Isolated from C. ammoniagenes

  • Park, Jong-Uk;Jo, Jae-Hyung;Kim, Young-Ji;Chung, So-Sun;Lee, Jin-Ho;Lee, Hyune-Hwan
    • Journal of Microbiology and Biotechnology
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    • v.18 no.4
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    • pp.639-647
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    • 2008
  • The heat-inducible expression vectors for Corynebacterium glutamicum and C. ammoniagenes were constructed by using the ${\lambda}O_L1$ and the cryptic promoters, CJ1 and CJ4 that express genes constitutively in C. ammoniagenes. Although the promoters were isolated from C. ammoniagenes, CJ1 and CJ4 were also active in C. glutamicum. To construct vectors, the $O_L1$ from the ${\lambda}P_L$ promoter was isolated and fused to the CJ1 and CJ4 promoters by recombinant PCR. The resulting artificial promoters, CJ1O and CJ4O, which have one ${\lambda}O_L1$, and CJ1OX2, which has two successive ${\lambda}O_L1$, were fused to the green fluorescent protein (GFP) gene followed by subcloning into pCES208. The expression of GFP in the corynebacteria harboring the vectors was regulated successfully by the temperature-sensitive cI857 repressor. Among them, C. ammoniagenes harboring plasmid pCJ1OX2G containing GFP fused to CJ1OX2 showed more GFP than the other ones and the expression was tightly regulated by the repressor. To construct the generally applicable expression vector using the plasmid pCJ1OX2G, the His-tag, enterokinase (EK) moiety, and the MCS were inserted in front of the GFP gene. Using the vector, the expression of pyrR from C. glutamicum was tried by temperature shift-up. The results indicated that the constructed vectors (pCeHEMG) can be successfully used in the expression and regulation of foreign genes in corynebacteria.

APPLICATIONS OF CRITICAL POINT THEOREMS TO NONLINEAR BEAM PROBLEMS

  • Choi, Q-Heung;Jin, Ying-Hua;Choi, Kyung-Pyo
    • Honam Mathematical Journal
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    • v.29 no.1
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    • pp.19-40
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    • 2007
  • Let L be the differential operator, Lu = $u_{tt}+u_{xxxx}$. We consider nonlinear beam equations, Lu + $bu^+$ = j, in H, where H is the Hilbert space spanned by eigenfunctions of L. We reveal the existence of multiple solutions of the nonlinear beam problems by critical point theorems.

HYPERSURFACES IN 𝕊4 THAT ARE OF Lk-2-TYPE

  • Lucas, Pascual;Ramirez-Ospina, Hector-Fabian
    • Bulletin of the Korean Mathematical Society
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    • v.53 no.3
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    • pp.885-902
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    • 2016
  • In this paper we begin the study of $L_k$-2-type hypersurfaces of a hypersphere ${\mathbb{S}}^{n+1}{\subset}{\mathbb{R}}^{n+2}$ for $k{\geq}1$ Let ${\psi}:M^3{\rightarrow}{\mathbb{S}}^4$ be an orientable $H_k$-hypersurface, which is not an open portion of a hypersphere. Then $M^3$ is of $L_k$-2-type if and only if $M^3$ is a Clifford tori ${\mathbb{S}}^1(r_1){\times}{\mathbb{S}}^2(r_2)$, $r^2_1+r^2_2=1$, for appropriate radii, or a tube $T^r(V^2)$ of appropriate constant radius r around the Veronese embedding of the real projective plane ${\mathbb{R}}P^2({\sqrt{3}})$.

The Study on Bone Mineral Density Measurement Error in Accordance with Change in ROI by Utilizing Dual Energy X-ray Absorptiometry (DEXA를 이용한 골밀도 측정시 검사자의 ROI 변화에 따른 골밀도 측정값의 오차에 관한 연구)

  • Lee, Yun-Hong;Lee, In-Ja;Yong, Hyung-Jin
    • Journal of radiological science and technology
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    • v.35 no.1
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    • pp.1-7
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    • 2012
  • Dual Energy X-ray Absorptiometry(DEXA) is commonly used to diagnose Osteoporosis. The errors of DEXA bone density operation are caused by operator, bone mineral density meter, blood testing, patient. We focus on operator error then study about how much influence operator's region of intest(ROI) in bone testing result. During from March to July in 2011. 50 patients ware selected respectively from 30, 40, 50, 60, and 70 age groups who came to Korea University Medical Center(KUMC) for their Osteoporosis treatment. A-test was performed with usually ROI and B-test was performed with most widely ROI. Then, We compare A-test and B-test for find maximum difference of T-score error which occurred operator ROI controlling. Standard deviation of T-score of B-test showed 0.1 higher then A-test in femur neck. Standard deviation of B-test showed 0.2 higher then A-test in Ward's area which in Greater trocanter and Inter trocanter. Standard deviation of B-test showed 0,1 lower then A-test in L-1. Bone density testing about Two hundred patients results are as follow. When operator ROI was changed wider than normal ROI, bone density of femur was measured more higher but bone density of L-spine was measured more lower then normal bone density. That means, sometime DEXA bone density testing result is dependent by operator ROI controlling. This is relevant with the patient's medicine and health insurance, thus, tester always keep the size of ROI for to prevent any problem in the patient.

Spectral p-dilations and polynomially bounded operators

  • Lee, Mi-Young;Lee, Sang-Hun
    • Journal of the Korean Mathematical Society
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    • v.32 no.4
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    • pp.889-895
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    • 1995
  • Let $H$ be a separable, infinite dimensional, complex Hilbert space and let $L(H)$ denote the algebra of all bounded linear operators on $H$.

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A LOWER ESTIMATE OF THE BANACH-MAZUR DISTANCES ON THE QUASI-NORMED SPACES

  • Kang, JeongHeung
    • Korean Journal of Mathematics
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    • v.7 no.2
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    • pp.207-213
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    • 1999
  • In this paper we estimate a lower bound of the Banach-Mazur distance between a finite dimensional nonlocally convex space and its Banach envelope space by investigating the properties of the nonlocally convex space and the projection constant which are obtained by factoring the identity operator through $l^k_{\infty}$ on the quasi-normed spaces.

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FRAME AND LATTICE SAMPLING THEOREM FOR SUBSPACES OF $L^2$��

  • Liu, Zhan-Wei;Hu, Guo-En
    • Journal of applied mathematics & informatics
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    • v.27 no.1_2
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    • pp.195-203
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    • 2009
  • In this paper, a necessary and sufficient condition for lattice sampling theorem to hold for frame in subspaces of $L^2$(R) is established. In addition, we obtain the formula of lattice sampling function in frequency space. Furthermore, by discussing the parameters in Theorem 3.1, some corresponding corollaries are derived.

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