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101.
In this paper we show that the cyclotomic factors of the En Coxeter polynomials depend only on the value of nmod360, and come exclusively from spherical subdiagrams. 相似文献
102.
We exploit difference equations to establish sharp inequalities on the extreme zeros of the classical discrete orthogonal polynomials, Charlier, Krawtchouk, Meixner and Hahn. We also provide lower bounds on the minimal distance between their consecutive zeros. 相似文献
103.
Dragan Juki 《Journal of Approximation Theory》2009,156(2):212-222
For the given data (wi,xi,yi), i=1,…,M, we consider the problem of existence of the best discrete approximation in lp norm (1≤p<∞) by reciprocals of real polynomials. For this problem, the existence of best approximations is not always guaranteed. In this paper, we give a condition on data which is necessary and sufficient for the existence of the best approximation in lp norm. This condition is theoretical in nature. We apply it to obtain several other existence theorems very useful in practice. Some illustrative examples are also included. 相似文献
104.
D.S. Lubinsky 《Journal of Functional Analysis》2009,256(11):3688-3729
We prove that de Branges spaces of entire functions describe universality limits in the bulk for random matrices, in the unitary case. In particular, under mild conditions on a measure with compact support, we show that each possible universality limit is the reproducing kernel of a de Branges space of entire functions that equals a classical Paley-Wiener space. We also show that any such reproducing kernel, suitably dilated, may arise as a universality limit for sequences of measures on [−1,1]. 相似文献
105.
Grzegorz Nowak 《Journal of Mathematical Analysis and Applications》2009,350(1):50-55
In this paper, we introduce the generalized q-Bernstein polynomials based on the q-integers and we study approximation properties of these operators. In special case, we obtain Stancu operators or Phillips polynomials. 相似文献
106.
Salih Yalinba Mehmet Sezer Hüseyin Hilmi Sorkun 《Applied mathematics and computation》2009,210(2):334-349
In this study, a Legendre collocation matrix method is presented to solve high-order Linear Fredholm integro-differential equations under the mixed conditions in terms of Legendre polynomials. The proposed method converts the equation and conditions to matrix equations, by means of collocation points on the interval [−1, 1], which corresponding to systems of linear algebraic equations with Legendre coefficients. Thus, by solving the matrix equation, Legendre coefficients and polynomial approach are obtained. Also examples that illustrate the pertinent features of the method are presented and by using the error analysis, the results are discussed. 相似文献
107.
The method for the minimum-phase (MP) finite impulse response (FIR) filter design, based on Rouche’s theorem from complex analysis is presented here. The filter is designed directly from a given specification. The method uses the cosine filters and the sharpening technique resulting in a multiplierless filter. 相似文献
108.
I. P?v?loiu 《Applied mathematics and computation》2009,215(7):2663-2672
In this paper we study a third order Steffensen type method obtained by controlling the interpolation nodes in the Hermite inverse interpolation polynomial of degree 2. We study the convergence of the iterative method and we provide new convergence conditions which lead to bilateral approximations for the solution; it is known that the bilateral approximations have the advantage of offering a posteriori bounds of the errors. The numerical examples confirm the advantage of considering these error bounds. 相似文献
109.
Amy M. Fu 《Journal of Combinatorial Theory, Series A》2009,116(4):903-917
We give non-symmetric versions of the Cauchy kernel and Littlewood's kernels, corresponding to the types A, B, C and D, of the classical groups. Defining two families of key polynomials (one of them being the Demazure characters), we show that these new kernels are diagonal in the basis of key polynomials. We define scalar products such that the two families of key polynomials are adjoint to each other. 相似文献
110.
The multivariate integer Chebyshev problem is to find polynomials with integer coefficients that minimize the supremum norm
over a compact set in ℂ
d
. We study this problem on general sets but devote special attention to product sets such as cube and polydisk. We also establish
a multivariate analog of the Hilbert–Fekete upper bound for the integer Chebyshev constant, which depends on the dimension
of space. In the case of single-variable polynomials in the complex plane, our estimate coincides with the Hilbert–Fekete
result.
相似文献