Library

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Manuscripta mathematica 63 (1989), S. 469-478 
    ISSN: 1432-1785
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract We introduce a definition of nonlinear n-widths and then determine the n-widths of the unit ball of the Sobolev spaceW p r inL q. We prove that in the sense of these widths the manifold of splines of fixed degree with n free knots is optimal for approximating functions in these Sobolev spaces.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Numerische Mathematik 60 (1991), S. 477-492 
    ISSN: 0945-3245
    Keywords: 65D15
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Summary A functionf ∈C (Ω), $$\Omega \subseteq \mathbb{R}^s $$ is called monotone on Ω if for anyx, y ∈ Ω the relation x − y ∈ ∝ + s impliesf(x)≧f(y). Given a domain $$\Omega \subseteq \mathbb{R}^s $$ with a continuous boundary ∂Ω and given any monotone functionf on ∂Ω we are concerned with the existence and regularity ofmonotone extensions i.e., of functionsF which are monotone on all of Ω and agree withf on ∂Ω. In particular, we show that there is no linear mapping that is capable of producing a monotone extension to arbitrarily given monotone boundary data. Three nonlinear methods for constructing monotone extensions are then presented. Two of these constructions, however, have the common drawback that regardless of how smooth the boundary data may be, the resulting extensions will, in general, only be Lipschitz continuous. This leads us to consider a third and more involved monotonicity preserving extension scheme to prove that, when Ω is the unit square [0, 1]2 in ∝2, strictly monotone analytic boundary data admit a monotone analytic extension.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Constructive approximation 8 (1992), S. 187-201 
    ISSN: 1432-0940
    Keywords: 41A25 ; 41A20 ; Degree of approximation ; Monotone approximation ; Polynomials
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract We prove that forf∈L p , 0〈p〈1, andk a positive integer, there exists an algebraic polynomialP n of degree ≤n such that $$\left\| {f - P_n } \right\|_p \leqslant C\omega _k^\varphi \left( {f,\frac{1}{n}} \right)_p $$ whereω k ϕ (f,t)p is the Ditzian-Totik modulus of smoothness off inL p , andC is a constant depending only onk andp. Moreover, iff is nondecreasing andk≤2, then the polynomialP n can also be taken to be nondecreasing.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Constructive approximation 3 (1987), S. 239-248 
    ISSN: 1432-0940
    Keywords: Multivariate approximation ; Splines with free knots ; Order of approximation ; Besov spaces ; 41A20
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract We introduce a definition of free multivariate splines which generalizes the univariate notion of splines with free knots. We then concentrate on the simplest case, piecewise constant functions and characterize some classes of functions which have a prescribed order of approximation inL p by these splines. These characterizations involve the classical Besov spaces.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Constructive approximation 9 (1993), S. 123-166 
    ISSN: 1432-0940
    Keywords: Primary 41A63 ; 46C99 ; Secondary 41A30 ; 41A15 ; 42B99 ; 46E20 ; Wavelets ; Multiresolution ; Shift-invariant spaces ; Box splines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract A new approach for the construction of wavelets and prewavelets onR d from multiresolution is presented. The method uses only properties of shift-invariant spaces and orthogonal projectors fromL 2(R d ) onto these spaces, and requires neither decay nor stability of the scaling function. Furthermore, this approach allows a simple derivation of previous, as well as new, constructions of wavelets, and leads to a complete resolution of questions concerning the nature of the intersection and the union of a scale of spaces to be used in a multiresolution.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Constructive approximation 1 (1985), S. 323-331 
    ISSN: 1432-0940
    Keywords: 41 A 10 ; 41 A 25 ; 41 A 29 ; Monotone approximation by algebraic polynomials ; Degree of approximation ; Pointwise estimates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract We prove that iff is increasing on [−1,1], then for eachn=1,2,... there is an increasing algebraic polynomialP n of degreen such that |f(x)−P n (x)|≤cω 2(f,√1−x 2/n), whereω 2 is the second-order modulus of smoothness. These results complement the classical pointwise estimates of the same type for unconstrained polynomial approximation. Using these results, we characterize the monotone functions in the generalized Lipschitz spaces through their approximation properties.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Constructive approximation 9 (1993), S. 121-121 
    ISSN: 1432-0940
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Book
    Book
    Berlin ; Heidelberg :Springer,
    Title: Multiscale, nonlinear and adaptive approximation /
    Contributer: DeVore, Ronald A. , Dahmen, Wolfgang
    Publisher: Berlin ; Heidelberg :Springer,
    Year of publication: 2009
    Pages: XXIII, 659 S. : , Ill., graph. Darst. ; , 24 cm
    ISBN: 978-3-642-03412-1
    Type of Medium: Book
    Language: English
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Book
    Book
    Cambridge :Cambridge Univ. Press,
    Title: Foundations of computational mathematics /; 284
    Contributer: DeVore, Ronald A.
    Edition: 1. publ.
    Publisher: Cambridge :Cambridge Univ. Press,
    Year of publication: 2001
    Pages: VIII, 400 S. : Ill., graph. Darst.
    Series Statement: London Mathematical Society lecture note series 284
    ISBN: 0-521-00349-0
    Type of Medium: Book
    Language: English
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Book
    Book
    Berlin [u.a.] :Springer,
    Title: Constructive approximation /; 303
    Author: DeVore, Ronald A.
    Contributer: Lorentz, George G.
    Publisher: Berlin [u.a.] :Springer,
    Year of publication: 1993
    Pages: X, 449 S. : , graph. Darst.
    Series Statement: ¬Die¬ Grundlehren der mathematischen Wissenschaften 303
    ISBN: 3-540-50627-6 , 0-387-50627-6
    Type of Medium: Book
    Language: English
    URL: 04
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...