• Title/Summary/Keyword: $C^2-continuity$

Search Result 104, Processing Time 0.026 seconds

Sets of Complete Continuity

  • Park, Jae-Myung
    • Journal of the Chungcheong Mathematical Society
    • /
    • v.5 no.1
    • /
    • pp.99-101
    • /
    • 1992
  • In this paper, we study some properties of sets of complete continuity. Moreover, we prove that if the subsets $C_1$ and $C_2$ of a Banach space X are sets of complete continuity, then so is the set $C_1{\times}C_2$ in the product space $X{\times}X$.

  • PDF

Construction of Cubic Triangular Patches with $C^1$ Continuity around a Corner

  • Zhang, Renjiang;Liu, Ligang;Wang, Guojin;Ma, Weiyin
    • International Journal of CAD/CAM
    • /
    • v.6 no.1
    • /
    • pp.149-156
    • /
    • 2006
  • This paper presents a novel approach for constructing a piecewise triangular cubic polynomial surface with $C^1$ continuity around a common corner vertex. A $C^1$ continuity condition between two cubic triangular patches is first derived using mixed directional derivatives. An approach for constructing a surface with $C^1$ continuity around a corner is then developed. Our approach is easy and fast with the virtue of cubic reproduction, local shape controllability, $C^2$ continuous at the corner vertex. Some experimental results are presented to show the applicability and flexibility of the approach.

ABSOLUTE CONTINUITY OF THE REPRESENTING MEASURES OF THE HYPERGEOMETRIC TRANSLATION OPERATORS ATTACHED TO THE ROOT SYSTEM OF TYPE B2 AND C2

  • Trimeche, Khalifa
    • Korean Journal of Mathematics
    • /
    • v.22 no.4
    • /
    • pp.711-723
    • /
    • 2014
  • We prove in this paper the absolute continuity of the representing measures of the hypergeometric translation operators $\mathcal{T}_x$ and $\mathcal{T}_x^W$ associated respectively to the Cherednik operators and the Heckman-Opdam theory attached to the root system of type $B_2$ and $C_2$ which are studied in [9].

Fuzzy c-Continuous Mappings

  • Hur, K.;Ryon, J.H.
    • International Journal of Fuzzy Logic and Intelligent Systems
    • /
    • v.1 no.1
    • /
    • pp.50-55
    • /
    • 2001
  • We generalize mainly the concept of c-continuity of a mapping due to Gentry and Hoyle III in fuzzy setting. And we investigate some properties of fuzzy c-continuous mappings.

  • PDF

ON HOMOMORPHISMS ON $C^*$-ALGEBRAS

  • Cho, Tae-Geun
    • Bulletin of the Korean Mathematical Society
    • /
    • v.22 no.2
    • /
    • pp.89-93
    • /
    • 1985
  • One of the most important problems in automatic continuity theory is to solve the question of continuity of an algebra homomorphism from a Banach algebra into a semisimple Banach algebra with dense range. Many results on this subject are obtained imposing some conditions on the domains or the ranges of homomorphisms. For most recent results and references in automatic continuity theory one may refer to [1], [4] and [5]. In this note we study some properties of homomorphisms from $C^{*}$-algebras into Banach algebras. It is shown that the range of an isomorphism from a $C^{*}$-algebra into a Banach algebra contains no non zero element of the radical of B. Using this result we show that the same holds for a continuous homomorphism, hence a Banach algebra which is the image of a $C^{*}$-algebra under a continuous homomorphism is necessarily semisimple. Thus if there is a homomorphism from a $C^{*}$-algebra onto a non-semisimple Banach algebra it must be discontinuous. Also it follows that every non zero homomorphism from a $C^{*}$-algebra into a radical algebra is discontinuous. Then we make a brief observation on the behavior of quasinilpotent element of noncommutative $C^{*}$-algebras in relation with continuous homomorphisms.momorphisms.

  • PDF

Meshless formulation for shear-locking free bending elements

  • Kanok-Nukulchai, W.;Barry, W.J.;Saran-Yasoontorn, K.
    • Structural Engineering and Mechanics
    • /
    • v.11 no.2
    • /
    • pp.123-132
    • /
    • 2001
  • An improved version of the Element-free Galerkin method (EFGM) is presented here for addressing the problem of transverse shear locking in shear-deformable beams with a high length over thickness ratio. Based upon Timoshenko's theory of thick beams, it has been recognized that shear locking will be completely eliminated if the rotation field is constructed to match the field of slope, given by the first derivative of displacement. This criterion is applied directly to the most commonly implemented version of EFGM. However in the numerical process to integrate strain energy, the second derivative of the standard Moving Least Square (MLS) shape functions must be evaluated, thus requiring at least a $C^1$ continuity of MLS shape functions instead of $C^0$ continuity in the conventional EFGM. Yet this hindrance is overcome effortlessly by only using at least a $C^1$ weight function. One-dimensional quartic spline weight function with $C^2$ continuity is therefore adopted for this purpose. Various numerical results in this work indicate that the modified version of the EFGM does not exhibit transverse shear locking, reduces stress oscillations, produces fast convergence, and provides a surprisingly high degree of accuracy even with coarse domain discretizations.

CONTINUITY OF HOMOMORPHISMS BETWEEN BANACH ALGEBRAS

  • Cho, Tae-Geun
    • Bulletin of the Korean Mathematical Society
    • /
    • v.20 no.2
    • /
    • pp.71-74
    • /
    • 1983
  • The problems of the continuity of homomorphisms between Banach algebras have been studied widely for the last two decades to obtain various fruitful results, yet it is far from characterizing the calss of Banach algebras for which each homomorphism from a member of the class into a Banach algebra is conitnuous. For commutative Banach algebras A and B a simple proof shows that every homomorphism .theta. from A into B is continuous provided that B is semi-simple, however, with a non semi-simple Banach algebra B examples of discontinuous homomorphisms from C(K) into B have been constructed by Dales [6] and Esterle [7]. For non commutative Banach algebras the problems of automatic continuity of homomorphisms seem to be much more difficult. Many positive results and open questions related to this subject may be found in [1], [3], [5] and [8], in particular most recent development can be found in the Lecture Note which contains [1]. It is well-known that a$^{*}$-isomorphism from a $C^{*}$-algebra into another $C^{*}$-algebra is an isometry, and an isomorphism of a Banach algebra into a $C^{*}$-algebra with self-adjoint range is continuous. But a$^{*}$-isomorphism from a $C^{*}$-algebra into an involutive Banach algebra is norm increasing [9], and one can not expect each of such isomorphisms to be continuous. In this note we discuss an isomorphism from a commutative $C^{*}$-algebra into a commutative Banach algebra with dense range via separating space. It is shown that such an isomorphism .theta. : A.rarw.B is conitnuous and maps A onto B is B is semi-simple, discontinuous if B is not semi-simple.

  • PDF

ON THE CONSTRUCTION AND THE EXISTENCE OF PARAMETRIC CUBIC$g^2$ B-SPLINE

  • Kimn, Ha-Jine
    • Communications of the Korean Mathematical Society
    • /
    • v.10 no.2
    • /
    • pp.483-490
    • /
    • 1995
  • A parametric cubic spline interpolating at fixed number of nodes is constructed by formulating a parametric cubic $g^2$ B-splines $S_3(t)$ with not equally spaced parametric knots. Since the fact that each component is in $C^2$ class is not enough to provide the geometric smoothness of parametric curves, the existence of $S_3(t)$ oriented toward the modified second-order geometric continuity is focalized in our work.

  • PDF