平面上的近似连续积分

近似连续Ｐｅｒｒｏｎ 积分首先由Ｂｕｒｋｉｌｌ提出,称之为ＡＰ积分,由于近似复盖具有划分性质,因而可以给出ＡＰ积分的Ｒｉｅｍ ａｎｎ型定义． 但是,在平面上近似复盖是否具有划分性质还不知道． 本文给出了一种方法,用这种方法可以在平面上给出ＡＰ积分的Ｒｉｅｍ ａｎｎ型定义而不需要证明划分的存在性．     

一类奇异积分方程组的样条间接近似解法

本文利用三次复插值样条函数给了定义于复平面上光滑封闭曲线上的一类奇异积分方程组（１）的一种间接近似解法，讨论了误差估计和一致收敛性。     

多元弱奇异积分方程近似解直接方法的优化

本文研究了多元弱奇异第二类Ｆｒｅｄｈｏｌｍ积分方程数ψ在适应直接方法意义下的最优近似解产 们推广了文献「１」中的相关结果。     

Stokes型积分——微分方程的Galerkin近似

本文讨论一类具有Stokes方程结构的积分一微分方程的Galerkin近似，论证了近似解的存在唯一性，并分别导出速度和压力近似解的最优阶L_2模误差估计。     

带位移非线性奇异积分方程的离散近似解

将积分区间划分为2N 等分后,我们定义了带位移的离散奇异算子■~(N).对于广义 Hilder 空间 H_(α,β,γ)中的函数 u(x),被带位移奇异算子作用后与■(N)_u 的差在分点处是 O((ln N)/(Nγ)).算子■(N)是一致有界的。利用它,我们给出了一类带位移的非线性奇异积分(哥西核)方程的离散近似解     

Hilbert空间中算子广义逆的积分表示

利用算子矩阵分块的技巧,得到了Hilbert空间中算子的Moore-Penrose逆和Drazin逆的积分表示.给出了较为简洁的证明,同时将有限维的结论推广到无限维的情形.     

一类非线性奇异积分方程的离散近似解及其误差估计

当函数f(x,t,u)满足一些[1]中常假定的条件时,我们可借助算子S~(N)和不等式证明非线性奇异积分方程有唯一的离散近似解,这个解可用关于距离的逐次逼近法得到.     

覆盖下近似算子的拓扑性质

在不限制U为有限论域的情况下,研究了覆盖下近似算子XL和CL的拓扑性质。证明了覆盖下近似算子XL是内部算子,而且由XL生成的拓扑TXL为包含由覆盖C本身作为子基生成的拓扑TC的最小Alexandrov拓扑。特别地,当U为有限论域时,TXL=TC.然而,覆盖下近似算子CL不是内部算子。当覆盖C为某拓扑的基时,CL是内部算子,且此时由CL生成的拓扑TCL与TC是同一个拓扑。若进一步要求U为有限论域,则TCL=TXL=TC,进而CL=XL.     

半平面中调和函数的积分表示和估计

对于半平面中的调和函数,在本文中证明了如果它的正部满足某些限制增长条件,则它可以用半平面边界上的积分表示出来并且它的绝对值也满足类似的增长条件,这一结果改进了在半平面中调和函数的某些经典结果.     

Non Integral Regularizing Operators on Lp- Spaces

We present bounded positivity preserving operators from L_p(?) to L_q (?), for 1 < p < ∞, 1/p-1/q < 1/2, which are not integral operators.     

星像函数的某些积分算子（英）

ＣｅｒｔａｉｎＩｎｔｅｇｒａｌＯｐｅｒａｔｏｒｓｆｏｒＳｔａｒｌｉｋｅＦｕｎｃｔｉｏｎｓＢ．Ａ．ＵｒａｌｅｇａｄｄｉＣ．Ｓｏｍａｎａｔｈａ（Ｄｅｐｔ．ｏｆＭａｔｈ．，ＫａｒｎａｔａｋＵｎｉｖｅｒｓｉｔｙ，Ｄｈａｒｗａｄ５８０００３，Ｉｎｄｉａ）Ｃｅｒ...     

用小波限制紧算子逼近奇异积分算子的速度

根据Beylin-Coifman-Rokhlin和Yang的观点，用合适的小波基可以刻画性地研究C.Z算子或拟微分算子，这样就可以用小波来计算算子，比如可以从奇异积分算子的B-C-R算法刻画出发，用小波限制紧算子进行逼近，本文旨在计算作为原算子与逼近算子的差的误差算子的H1到L1的连续性范数的最佳衰减速度和在Lp上的连续性范数的衰减速度的范围。     

Spline Collocation for Cordial Volterra Integral Equations

We study the convergence and convergence speed of two versions of spline collocation methods on the uniform grids for linear Volterra integral equations of the second kind with noncompact operators.     

Spline Collocation-Interpolation Method for Linear and Nonlinear Cordial Volterra Integral Equations

We study the convergence and convergence speed of the discontinuous spline collocation and collocation-interpolation methods on uniform grids for linear and nonlinear Volterra integral equations of the second kind with noncompact operators.     

向量值奇异积分算子的交换子

本文分别讨 论了 Ｈａｒｄｙ Ｌｉｔｔｌｅｗ ｏｏｄ 极大 算子和奇 异积分算 子的交换 子在加权 Ｈｅｒｚ 空间 ,加权 Ｌｐ空间中的 有界性     

Spectrum Problems for Singular Integral Operators with Carleman Shift

In this paper we are concerned with the complete spectral analysis for the operator 𝒯 = 𝒳𝒮𝒰 in the space L_p(𝕋) (𝕋 denoting the unit circle), where 𝒳 is the characteristic function of some arc of 𝕋, 𝒮 is the singular integral operator with Cauchy kernel and 𝒰 is a Carleman shift operator which satisfies the relations 𝒰² = I and 𝒮𝒰 = ±𝒰𝒮, where the sign + or — is taken in dependence on whether 𝒰 is a shift operator on L_p(𝕋) preserving or changing the orientation of 𝕋. This includes the identification of the Fredholm and essential parts of the spectrum of the operator 𝒯, the determination of the defect numbers of 𝒯 — λI, for λ in the Fredholm part of the spectrum, as well as a formula for the resolvent operator.     

Representation of Fourier Integral Operators Using Shearlets

Traditional methods of time-frequency and multiscale analysis, such as wavelets and Gabor frames, have been successfully employed for representing most classes of pseudodifferential operators. However, these methods are not equally effective in dealing with Fourier Integral Operators in general. In this article, we show that the shearlets, recently introduced by the authors and their collaborators, provide very efficient representations for a large class of Fourier Integral Operators. The shearlets are an affine-like system of well-localized waveforms at various scales, locations and orientations, which are particularly efficient in representing anisotropic functions. Using this approach, we prove that the matrix representation of a Fourier Integral Operator with respect to a Parseval frame of shearlets is sparse and well-organized. This fact recovers a similar result recently obtained by Candès and Demanet using curvelets, which illustrates the benefits of directional multiscale representations (such as curvelets and shearlets) in the study of those functions and operators where traditional multiscale methods are unable to provide the appropriate geometric analysis in the phase space. The second author was supported in part by a National Science Foundation grant DMS 0604561.     

On the Algebra of Pair Integral Operators with Homogeneous Kernels

In this paper, we study the Banach algebra generated by multidimensional pair integral operators with homogeneous kernels. We describe necessary and sufficient conditions for operators from the algebra to be Fredholm and present a formula for calculating the index.     

BMO与弱核条件下的Calderón-Zygmund算子交换子的有界性

本文证明了BMO与弱核条件下Calderón-Zygmund奇异积分算子的交换子 [B,T]f=BTf-T(Bf)的L2有界性,这里B ∈BMO,T对增生的b1,b2,满足 T(b1)∈BMO,T*(b2)∈BMO,b2Tb1∈WBP．