We investigate the following problem in this paper: where there is an unique 1-periodic discrete quadratic spline s∈S(3, p, h) satisfying certain interpolatory condition for a 1-periodic discrete function de- fined o...We investigate the following problem in this paper: where there is an unique 1-periodic discrete quadratic spline s∈S(3, p, h) satisfying certain interpolatory condition for a 1-periodic discrete function de- fined on [0, 1]_k. The anwser is affirmative.展开更多
This paper gives the weighted Lp convergence rate estimations of the Grunwald interpolatory polynomials based on the zeros of Chebyshev polynomials of the first kind, and proves that the order of the estimations is op...This paper gives the weighted Lp convergence rate estimations of the Grunwald interpolatory polynomials based on the zeros of Chebyshev polynomials of the first kind, and proves that the order of the estimations is optimal for p≥1.展开更多
In Chen et al.(J.Sci.Comput.81(3):2188–2212,2019),we considered a superconvergent hybridizable discontinuous Galerkin(HDG)method,defned on simplicial meshes,for scalar reaction-difusion equations and showed how to de...In Chen et al.(J.Sci.Comput.81(3):2188–2212,2019),we considered a superconvergent hybridizable discontinuous Galerkin(HDG)method,defned on simplicial meshes,for scalar reaction-difusion equations and showed how to defne an interpolatory version which maintained its convergence properties.The interpolatory approach uses a locally postprocessed approximate solution to evaluate the nonlinear term,and assembles all HDG matrices once before the time integration leading to a reduction in computational cost.The resulting method displays a superconvergent rate for the solution for polynomial degree k≥1.In this work,we take advantage of the link found between the HDG and the hybrid high-order(HHO)methods,in Cockburn et al.(ESAIM Math.Model.Numer.Anal.50(3):635–650,2016)and extend this idea to the new,HHO-inspired HDG methods,defned on meshes made of general polyhedral elements,uncovered therein.For meshes made of shape-regular polyhedral elements afne-equivalent to a fnite number of reference elements,we prove that the resulting interpolatory HDG methods converge at the same rate as for the linear elliptic problems.Hence,we obtain superconvergent methods for k≥0 by some methods.We thus maintain the superconvergence properties of the original methods.We present numerical results to illustrate the convergence theory.展开更多
This paper deals with eigenvalue problems for linear Fredholm integral equations of the second kind with weakly singular kernels. A new discrete method is proposed for the approximation of eigenvalues.Compactness of t...This paper deals with eigenvalue problems for linear Fredholm integral equations of the second kind with weakly singular kernels. A new discrete method is proposed for the approximation of eigenvalues.Compactness of the integral operator in L^1[0, 1] space is obtained. This method is based on the approximation of the integral operator by modified interpolatory projection. Different from traditional methods, norm convergence of operator approximation is proved theoretically. Further, convergence of eigenvalue approximation is obtained by analytical tools. Numerical examples are presented to illustrate the theoretical results and the efficiency of the method.展开更多
In [1], a kind of periodic cardinal interpolatory function (PCIF) is constructed, and they also use it to construct periodic wavelets. But the localizationl of PCIF is not known yet. In this paper, we studv the local ...In [1], a kind of periodic cardinal interpolatory function (PCIF) is constructed, and they also use it to construct periodic wavelets. But the localizationl of PCIF is not known yet. In this paper, we studv the local property of PCIF using two different methods. The results show that PCIF has very good localization. Some new properties of Bernoulli spline are also introduced.展开更多
The phenomenon of mixed-mode is one of the most important characteristics of switched delay systems. If a networked control system(NCS) with network induced delays and packet dropouts(NIDs & PDs) is recast as a sw...The phenomenon of mixed-mode is one of the most important characteristics of switched delay systems. If a networked control system(NCS) with network induced delays and packet dropouts(NIDs & PDs) is recast as a switched delay system, it is imperative to consider the effects of mixed-modes in the stability analysis for an NCS. In this paper, with the help of the interpolatory quadrature formula and the average dwell time method, stabilization of NCSs using a mixed-mode based switched delay system method is investigated based on a novel constructed Lyapunov-Krasovskii functional. With the Finsler's lemma, new exponential stabilizability conditions with less conservativeness are given for the NCS. Finally, an illustrative example is provided to verify the effectiveness of the developed results.展开更多
Given f being Holder continuous in a region GC. For the Cauchy principal integral where G is a smooth closed contour,lt is established that,if a sequence or smooth closed contours G(n ∈N ) smoothly convergent top,the...Given f being Holder continuous in a region GC. For the Cauchy principal integral where G is a smooth closed contour,lt is established that,if a sequence or smooth closed contours G(n ∈N ) smoothly convergent top,then the corresponding sequence I(Γm,f)is convergent to I (,f). Furthermore,when Γ is approximated by a sequence of complex cubic splines(Γ)interpolatory to Γ,the error is estimated.展开更多
文摘We investigate the following problem in this paper: where there is an unique 1-periodic discrete quadratic spline s∈S(3, p, h) satisfying certain interpolatory condition for a 1-periodic discrete function de- fined on [0, 1]_k. The anwser is affirmative.
文摘This paper gives the weighted Lp convergence rate estimations of the Grunwald interpolatory polynomials based on the zeros of Chebyshev polynomials of the first kind, and proves that the order of the estimations is optimal for p≥1.
基金G.Chen was supported by the National Natural Science Foundation of China(NSFC)Grant 11801063the Fundamental Research Funds for the Central Universities Grant YJ202030+1 种基金B.Cockburn was partially supported by the National Science Foundation Grant DMS-1912646J.Singler and Y.Zhang were supported in part by the National Science Foundation Grant DMS-1217122.
文摘In Chen et al.(J.Sci.Comput.81(3):2188–2212,2019),we considered a superconvergent hybridizable discontinuous Galerkin(HDG)method,defned on simplicial meshes,for scalar reaction-difusion equations and showed how to defne an interpolatory version which maintained its convergence properties.The interpolatory approach uses a locally postprocessed approximate solution to evaluate the nonlinear term,and assembles all HDG matrices once before the time integration leading to a reduction in computational cost.The resulting method displays a superconvergent rate for the solution for polynomial degree k≥1.In this work,we take advantage of the link found between the HDG and the hybrid high-order(HHO)methods,in Cockburn et al.(ESAIM Math.Model.Numer.Anal.50(3):635–650,2016)and extend this idea to the new,HHO-inspired HDG methods,defned on meshes made of general polyhedral elements,uncovered therein.For meshes made of shape-regular polyhedral elements afne-equivalent to a fnite number of reference elements,we prove that the resulting interpolatory HDG methods converge at the same rate as for the linear elliptic problems.Hence,we obtain superconvergent methods for k≥0 by some methods.We thus maintain the superconvergence properties of the original methods.We present numerical results to illustrate the convergence theory.
基金Supported by Scientific Research Project of Beijing Municipal Education Commission(No.KM201811417013,KM201711417002)
文摘This paper deals with eigenvalue problems for linear Fredholm integral equations of the second kind with weakly singular kernels. A new discrete method is proposed for the approximation of eigenvalues.Compactness of the integral operator in L^1[0, 1] space is obtained. This method is based on the approximation of the integral operator by modified interpolatory projection. Different from traditional methods, norm convergence of operator approximation is proved theoretically. Further, convergence of eigenvalue approximation is obtained by analytical tools. Numerical examples are presented to illustrate the theoretical results and the efficiency of the method.
基金supported partially by NFSC Grant supported by LAPC Grant
文摘In [1], a kind of periodic cardinal interpolatory function (PCIF) is constructed, and they also use it to construct periodic wavelets. But the localizationl of PCIF is not known yet. In this paper, we studv the local property of PCIF using two different methods. The results show that PCIF has very good localization. Some new properties of Bernoulli spline are also introduced.
基金supported by the National Natural Science Foundation of China(61573230,61473034,51777012)Beijing Nova Programme Interdisciplinary Cooperation Project(Z161100004916041)
文摘The phenomenon of mixed-mode is one of the most important characteristics of switched delay systems. If a networked control system(NCS) with network induced delays and packet dropouts(NIDs & PDs) is recast as a switched delay system, it is imperative to consider the effects of mixed-modes in the stability analysis for an NCS. In this paper, with the help of the interpolatory quadrature formula and the average dwell time method, stabilization of NCSs using a mixed-mode based switched delay system method is investigated based on a novel constructed Lyapunov-Krasovskii functional. With the Finsler's lemma, new exponential stabilizability conditions with less conservativeness are given for the NCS. Finally, an illustrative example is provided to verify the effectiveness of the developed results.
文摘Given f being Holder continuous in a region GC. For the Cauchy principal integral where G is a smooth closed contour,lt is established that,if a sequence or smooth closed contours G(n ∈N ) smoothly convergent top,then the corresponding sequence I(Γm,f)is convergent to I (,f). Furthermore,when Γ is approximated by a sequence of complex cubic splines(Γ)interpolatory to Γ,the error is estimated.
