1,720,999 research outputs found
Multiresolution analyses originated from nonstationary subdivision schemes
No full textWe analyze the properties of a new class of totally positive refinable functions obtained from nonstationary subdivision schemes. We show that the corresponding system of the integer translates is linearly independent, satisfies a Whitney-Schoenberg condition, reproduces polynomials up to a certain degree and generates a multiresolution analysis. Finally, pre-wavelets and bases on the interval are constructed
La mappa del mercato delle stampe a Roma nella prima metà dell'Ottocento
No full textSono esaminate le "botteghe" presso le quali si effettuava la vendita delle incisioni, come principale mezzo di diffusione dell'iconografia delle opere d'arte conservate in Roma e della conoscenza delle incisioni. E' allegata un'ampia tabella con l'ubicazione delle stesse, la produzione, gli anni di attività. L'ambito cronologico individuato è quello del primo Ottocento
Refinable functions and positive operators
No full textThe aim of this paper is to study the shape preserving properties of some positive operators constructed by means of B-bases on a finite interval. These bases are obtained by the integer translates of totally positive compactly supported refinable functions. We shall prove that the constructed B-bases generate, on the interval, multiresolution analyses which reproduce polynomials up to a certain degree. © 2004 Published by Elsevier B.V. on behalf of IMACS
Totally positive refinable functions with general dilation M
Full text linkWe construct a new class of approximating functions that are M-refinable and provide shape preserving approximations. The refinable functions in the class are smooth, compactly supported, centrally symmetric and totally positive. Moreover, their refinable masks are associated with convergent subdivision schemes. The presence of one or more shape parameters gives a great flexibility in the applications. Some examples for dilation M=4and M=5are also given
On some applications of the wavelet Galerkin method for boundary value problems.
No full textThe authors propose a wavelet Galerkin method to solve boundary value problems.They firrst develop a theory of scaling functions
based on cardinal B-spline functions.
A wavelet is obtained by translation and dilatation of. Further they add edge functions
with several vanishing moments. These techniques seem to reduce the ill-conditioning of
the discretized linear system. In the case study with
a=b= 0 and
f(x) corresponding to
u(x) =x(1-x)sin^2(6x),
they give nice results with very few terms. S. Hitotumat
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