Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 41 A 20  (1)
  • 42B15  (1)
  • Best constrained interpolation  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Order of approximation by electrostatic fields due to electrons (1985)
    Springer
    Constructive approximation 1 (1985), S. 121-135 
    Details
    ISSN: 1432-0940
    Keywords: 41 A 20 ; 30 E 10 ; Order of approximation ; Rational functions and electrostatic fields due to distribution of electrons ; Bers space ; Jordan domain ; Conformal mapping
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract LetD be a Jordan domain in the complex plane andA q (D) the Bers space with norm ∥ ∥ q . IfD is the unit disk, it is known that ∥S n 0∥2≥π/18, whereS n =∑ k=1 n l/(z−z nk ) withz nk ∈∂D, so that approximation in ∥ ∥ q ,q〈-2, is not possible. In this paper, we give an order of estimate of ∥f−S n ∥ q for 2〈q〈∞ when ∂D is a sufficiently smooth Jordan curve, and prove that this order of approximation is in general best possible.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01890026
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Constrained best approximation in Hilbert space (1990)
    Springer
    Constructive approximation 6 (1990), S. 35-64 
    Details
    ISSN: 1432-0940
    Keywords: Conical hull ; Polar of a cone ; Best constrained interpolation ; Primary 41A65 ; Secondary 41A29 ; 41A05
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract In this paper we study the characterization of the solution to the extremal problem inf{‖x‖x ∈C ∩M}, wherex is in a Hilbert spaceH, C is a convex cone, andM is a translate of a subspace ofH determined by interpolation conditions. We introduce a simple geometric property called the “conical hull intersection property” that provides a unifying framework for most of the basic results in the subject of optimal constrained approximation. Our approach naturally lends itself to considering the data cone as opposed to the constraint cone. A nice characterization of the solution occurs, for example, if the data vector associated withM is an interior point of the data cone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01891408
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Affine frames, quasi-affine frames, and their duals (1998)
    Springer
    Advances in computational mathematics 8 (1998), S. 1-17 
    Details
    ISSN: 1572-9044
    Keywords: affine frame ; quasi-affine frame ; dual ; sesquilinear operator ; translation invariance ; 42C15 (primary) ; 42B15 ; 47N40 (secondary)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract The notion of quasi-affine frame was recently introduced by Ron and Shen [9] in order to achieve shift-invariance of the discrete wavelet transform. In this paper, we establish a duality-preservation theorem for quasi-affine frames. Furthermore, the preservation of frame bounds when changing an affine frame to a quasi-affine frame is shown to hold without the decay assumptions in [9]. Our consideration leads naturally to the study of certain sesquilinear operators which are defined by two affine systems. The translation-invariance of such operators is characterized in terms of certain intrinsic properties of the two affine systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018975725857
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...