The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform

Maofa Wang - One of the best experts on this subject based on the ideXlab platform.

  • Compact Linear Combination of composition operators on Bergman spaces
    Journal of Functional Analysis, 2020
    Co-Authors: Boo Rim Choe, Hyungwoon Koo, Maofa Wang
    Abstract:

    Abstract Motivated by the question of Shapiro and Sundberg raised in 1990, study on Linear Combinations of composition operators has been a topic of growing interest. In this paper, we completely characterize the compactness of any Finite Linear Combination of composition operators with general symbols on the weighted Bergman spaces in two classical terms: one is a function theoretic characterization of Julia-Caratheodory type and the other is a measure theoretic characterization of Carleson type. Our approach is completely different from what has been known so far.

Asim Bhatti - One of the best experts on this subject based on the ideXlab platform.

  • ICASSP - A unified approach for constructing multi-wavelets
    IEEE International Conference on Acoustics Speech and Signal Processing, 2002
    Co-Authors: Huseyin Ozkaramanli, Asim Bhatti
    Abstract:

    A unified approach for constructing a large class of multi-wavelets is presented. This class includes Geranimo Hardin Massopust, Alpert and Daubechies-like multi-wavelets. The main emphasis is on approximation order of the resulting multi-scaling functions. The unified approach involves formulating the approximation order condition in the framework of super functions and recognizing that the generalized left eigenvectors of the resulting Finite down-sampled convolution matrix gives the coefficients that enter the Finite Linear Combination of scaling functions which produces the desired super function from which polynomials of desired degree can be locally approximated.

Huseyin Ozkaramanli - One of the best experts on this subject based on the ideXlab platform.

  • Construction of multi-wavelets from compactly supported refinable super functions
    Digital Signal Processing, 2003
    Co-Authors: Huseyin Ozkaramanli, Bülent Bilgehan
    Abstract:

    Abstract In this work, a new method for constructing multi-wavelets with arbitrary approximation order is presented. The approach uses refinable super functions which enable the formulation of approximation order condition in terms of a generalized eigenvalue equation. The generalized left eigenvectors of the resulting Finite down-sampled convolution matrix are recognized as the coefficients that enter the Finite Linear Combination of multi-scaling functions that produce the desired super function. The method is demonstrated by constructing a specific class of multi-wavelets with approximation order 2, which includes Geronimo–Hardin–Massopust (GHM) multi-wavelet as one of its parameterized solutions. A new multi-wavelet, possessing approximation order three and multiplicity two with support [0,2] and [0,3] is also constructed.

  • Unified approach for constructing multiwavelets with approximation order using refinable super-functions
    IEE Proceedings - Vision Image and Signal Processing, 2003
    Co-Authors: Huseyin Ozkaramanli
    Abstract:

    A unified approach for constructing a large class of multiwavelets is presented. This class includes Geronimo-Hardin-Massopust (1994), Alpert (1993), Finite element and Daubechies-like multiwavelets. The approach is based on the characterisation of approximation order of r multiscaling functions using a known compactly supported refinable super-function. The characterisation is formulated as a generalised eigenvalue equation. The generalised left eigenvectors of the Finite down-sampled convolution matrix L/sub f/ give the coefficients in the Finite Linear Combination of multiscaling functions that produce the desired super-function. The unified approach based on the super-function theory can be used to construct new multiwavelets with short support, high approximation order and symmetry.

  • ICASSP - A unified approach for constructing multi-wavelets
    IEEE International Conference on Acoustics Speech and Signal Processing, 2002
    Co-Authors: Huseyin Ozkaramanli, Asim Bhatti
    Abstract:

    A unified approach for constructing a large class of multi-wavelets is presented. This class includes Geranimo Hardin Massopust, Alpert and Daubechies-like multi-wavelets. The main emphasis is on approximation order of the resulting multi-scaling functions. The unified approach involves formulating the approximation order condition in the framework of super functions and recognizing that the generalized left eigenvectors of the resulting Finite down-sampled convolution matrix gives the coefficients that enter the Finite Linear Combination of scaling functions which produces the desired super function from which polynomials of desired degree can be locally approximated.

Helga Nutz - One of the best experts on this subject based on the ideXlab platform.

  • Satellite-to-satellite tracking and satellite gravity gradiometry (Advanced techniques for high-resolution geopotential field determination)
    Journal of Engineering Mathematics, 2002
    Co-Authors: Willi Freeden, Volker Michel, Helga Nutz
    Abstract:

    The purpose of satellite-to-satellite tracking (SST) and/or satellite gravity gradiometry (SGG) is to determine the gravitational field on and outside the Earth's surface from given gradients of the gravitational potential and/or the gravitational field at satellite altitude. In this paper both satellite techniques are analysed and characterized from a mathematical point of view. Uniqueness results are formulated. The justification is given for approximating the external gravitational field by Finite Linear Combination of certain gradient fields (for example, gradient fields of single-poles or multi-poles) consistent to a given set of SGG and/or SST data. A strategy of modelling the gravitational field from satellite data within a multiscale concept is described; illustrations based on the EGM96 model are given.

  • Satellite-to-Satellite Tracking and Satellite Gravity Gradiometry
    2001
    Co-Authors: Willi Freeden, Volker Michel, Helga Nutz
    Abstract:

    The purpose of satellite-to-satellite tracking (SST) and/or satellite gravity gradiometry (SGG) is to determine the gravitational field on and outside the Earth's surface from given gradients of the gravitational potential and/or the gravitational field at satellite altitude. In this paper both satellite techniques are analysed and characterized from mathematical point of view. Uniqueness results are formulated. The justification is given for approximating the external gravitational field by Finite Linear Combination of certain gradient fields (for example, gradient fields of single-poles or multi-poles) consistent to a given set of SGG and/or SST data. A strategy of modelling the gravitational field from satellite data within a multiscale concept is described; illustrations based on the EGM96 model are given.

Boo Rim Choe - One of the best experts on this subject based on the ideXlab platform.

  • Compact Linear Combination of composition operators on Bergman spaces
    Journal of Functional Analysis, 2020
    Co-Authors: Boo Rim Choe, Hyungwoon Koo, Maofa Wang
    Abstract:

    Abstract Motivated by the question of Shapiro and Sundberg raised in 1990, study on Linear Combinations of composition operators has been a topic of growing interest. In this paper, we completely characterize the compactness of any Finite Linear Combination of composition operators with general symbols on the weighted Bergman spaces in two classical terms: one is a function theoretic characterization of Julia-Caratheodory type and the other is a measure theoretic characterization of Carleson type. Our approach is completely different from what has been known so far.