Let {φn} be a sequence of rational functions with arbitrary complex poles, generated by a certain three-term recurrence relation. In this paper we show that under some mild conditions, the rational functions φn form an orthonormal system with respect to a Hermitian positive-definite inner product.

Let {φn} be a sequence of rational functions with arbitrary complex poles, generated by a certain three-term recurrence relation. In this paper we show that under some mild conditions the rational functions φn form an orthonormal system with respect to a Hermitian positive-definite inner product.

This report summarizes my contributions to copulas modeling. Two main research topics are addressed: The construction of semiparametric family of copulas based on a set of orthonormal functions and a matrix and the design of efficient estimation procedures.

We give characterizations of orthogonal families, tight frames and orthonormal bases of Gabor systems. The conditions we propose are stated in terms of equations for the Fourier transforms of the Gabor system’s generating functions.

For 0 < ρ < 1, let μρ be the Bernoulli convolution associated with ρ. Jorgensen and Pedersen [P. Jorgensen, S. Pedersen, Dense analytic subspaces in fractal L2-spaces, J. Anal. Math. 75 (1998) 185–228] proved that if ρ = 1/q where q is an even integer, then L(μρ) has an exponential orthonormal basis. We show that for any 0 < ρ < 1, L(μρ) contains an infinite orthonormal set of exponential funct...

We generalize the windowed Fourier transform to the variable-windowed Fourier transform. This generalization brings the Gabor transform and the wavelet transform under the same framework. Using frame theory we characterize frames and orthonormal bases for the variable windowed Fourier series (VWFS). These characterizations are formulated explicitly in terms of window functions. Therefore they c...

In this paper we develop a general and very simple construction for complete orthonormal bases for system identiication. This construction provides a unifying formulation of all known orthonormal bases since the common FIR and recently popular Laguerre and Kautz model structures are restrictive special cases of our construction as is another construction method based on balanced realisations of...

We prove estimates for the $L^p$-norms of systems functions and divergence-free vector that are orthonormal in Sobolev space $H^1$ on 2D sphere. As a corollary, order sharp constants embedding $H^1\hookrightarrow L^q$, $q&lt;\infty$, obtained Gagliardo-Nirenberg interpolation inequalities. Bibliography: 25 titles.

This paper presents a new robust algorithm for the identification of linear time-invariant systems in the frequency domain. The method is computationally very efficient, and accurately synthesises transfer functions which require a large amount of poles. Some numerical difficulties are avoided by combining the use of a Sanathanan-Koerner iteration and orthonormal rational functions.

In this paper, an overview about the identification of dynamic systems using orthonormal basis function models, such as those based on Laguerre and Kautz functions, is presented. The mathematical foundations of these models as well as their advantages and limitations are discussed within the contexts of linear, robust, and nonlinear identification. The discussions comprise a broad bibliographic...