检索结果-南通市图书馆

Applied Mathematics 2017年第7期8卷 967-986页

作者： Duncan Kioi Gathungu Alfio Borzì Institut für Mathematik Universit&auml t Würzburg Würzburg Germany

An efficient multigrid finite-differences scheme for solving elliptic Fredholm partial integro-differential equations (PIDE) is discussed. This scheme combines a second-order accurate finite difference discretization of the PIDE problem with a multigrid scheme that includes a fast multilevel integration of the Fredholm operator allowing the fast solution of the PIDE problem. Theoretical estimates of second-order accuracy and results of local Fourier analysis of convergence of the proposed multigrid scheme are presented. Results of numerical experiments validate these estimates and demonstrate optimal computational complexity of the proposed framework.

关键词： Elliptic Problems Fredholm operator Multigrid Schemes Finite Differences Numerical Analysis

THE SINE TRANSFORM operator IN THE BANACH SPACE OF SYMMETRIC MATRICES AND ITS APPLICATION IN IMAGE RESTORATION

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Numerical Mathematics A Journal of Chinese Universities(English Series) 1999年第2期8卷 231-242页

作者：高洁欣金小庆冼伟光

In this paper, we study an operator s which maps every n-by-n symmetric matrix A, to a matrix s(A_n) that minimizes || B_n-A_n || F over the set of all matrices B_n, that can be diagonalized by the sine transform. The matrix s(A_n), called the optimal sine transform preconditioner, is defined for any n-by-n symmetric matrices A_n. The cost of constructing s(A_n) is the same as that of optimal circulant preconditioner c(A_n) which is defined in [8], The s(A_n) has been proved in [6] to be a good preconditioner in solving symmetric Toeplitz systems with the preconditioned conjugate gradient (PCG) method. In this paper, we discuss the algebraic and geometric properties of the operator s, and compute its operator norms in Banach spaces of symmetric matrices. Some numerical tests and an application in image restoration are also given.

关键词： Toeplitz matrix optimal sine transform preconditioner since transform operator PCG method image restoration.

Exact Quasi-Classical Asymptotic beyond Maslov Canonical operator and Quantum Jumps Nature

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Applied Mathematics and Physics 2015年第5期3卷 584-607页

作者： Jaykov Foukzon Alex Potapov Stanislav Podosenov Israel Institute of Technology Haifa Israel The Institute of Radioengineering and Electronics (IRE) of Russian Academy of Sciences Moscow Russian All-Russian Scientific-Research Institute Moscow Russian

Exact quasi-classical asymptotic beyond WKB-theory and beyond Maslov canonical operator to the Colombeau solutions of the n-dimensional Schrodinger equation is presented. Quantum jumps nature is considered successfully. We pointed out that an explanation of quantum jumps can be found to result from Colombeau solutions of the Schrodinger equation alone without additional postulates.

关键词： Quantum Jumps Quantum Measurements Theory Quantum Averages Limiting Quantum Trajectory Schrodinger Equation Stochastic Quantum Jump Equation Colombeau Solution Feynman Path Integral Maslov Canonical operator Feynman-Colombeau Propagator

Variation of Parameters for Causal operator Differential Equations

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics 2017年第12期8卷 1883-1902页

作者： Reza R. Ahangar Mathematics Department Texas A & M University Kingsville Kingsville USA

The operator T from a domain D into the space of measurable functions is called a nonanticipating (causal) operator if the past information is independent from the future outputs. We will study the solution x(t) of a nonlinear operator differential equation where its changes depends on the causal operator T, and semigroup of operator A(t), and all initial parameters (t0, x0) . The initial information is described x(t)=φ(t) for almost all t ≤t0 and φ(t0) =φ0. We will study the nonlinear variation of parameters (NVP) for this type of nonanticipating operator differential equations and develop Alekseev type of NVP.

关键词： Nonlinear operator Differential Equations (NODE) Variation of Parameters Nonanticipating (Causal) Alekseev Theorem

Inverse Nodal Problems for the Sturm-Liouville operator with Some Nonlocal Integral Conditions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Applied Mathematics and Physics 2019年第1期7卷 111-122页

作者： Xiaojuan Qin Yunlan Gao Congmin Yang College of Sciences Inner Mongolia University of Technology Hohhot China

In this paper, we study three inverse nodal problems for the Sturm-Liouville operator with different nonlocal integral conditions. We get the conclusion that the potential function can be determined by a dense nodal s... 详细信息

关键词： Sturm-Liouville operator Inverse Nodal Problems Nonlocal Integral Conditions

Positive-Definite operator-Valued Kernels and Integral Representations

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics 2012年第12期3卷 1990-1999页

作者： L. Lemnete-Ninulescu Departament of Mathematics Politechnica University of Bucharest Bucharest Romania

A truncated trigonometric, operator-valued moment problem in section 3 of this note is solved. Let be a finite sequence of bounded operators, with arbitrary, acting on a finite dimensional Hilbert space H. A necessary and sufficient condition on the positivity of an operator kernel for the existence of an atomic, positive, operator-valued measure , with the property that for every with , the moment of coincides with the term of the sequence, is given. The connection between some positive definite operator-valued kernels and the Riesz-Herglotz integral representation of the analytic on the unit disc, operator-valued functions with positive real part in the class of operators in Section 4 of the note is studied.

关键词： Unitary-operator Self-Adjoint operator Joint Spectral Measure of a Commuting Tuple of operators Spectral Projector Complex Moments Analytic Vectorial Functions

Some Result of Stability and Spectra Properties on Semigroup of Linear operator

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Pure Mathematics 2019年第1期9卷 43-51页

作者： Kamilu Rauf Akinola Yussuff Akinyele Mfon Okon Etuk Rafiu Obashola Zubair Moses Adebowale Aasa Department of Mathematics University of Ilorin Ilorin Nigeria

This paper consists of some properties of a new subclass of semigroup of linear operator. The stability and spectra analysis of ω-order preserving partial contraction mapping (ω-OCPn) are obtained. The results show that operators on the proposed ω-OCPn are densely defined and closed. Several existing results in the literature are contained in this work.

关键词： Contraction Mapping Semigroup Banach Space Resolvent and Bounded operator

Entropy Number of Diagonal operator

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Applied Mathematics and Physics 2019年第3期7卷 738-745页

作者： Jin Chen Wenjing Lu Hanyue Xiao Yanan Wang Xin Tan School of Science Xihua University Chengdu China

In this paper, the entropy number of diagonal operator is discussed. On the one hand, the order of entropy number of the finite dimensional diagonal operator Dm:? (1≤q 详细信息

In this paper, the entropy number of diagonal operator is discussed. On the one hand, the order of entropy number of the finite dimensional diagonal operator Dm:? (1≤qoperator D: lp→lq(1≤q

关键词： Entropy Number The Finite Dimensional Diagonal operator The Infi nite Dimensional Diagonal operator

Equivalence of <i>K</i>-Functionals and Modulus of Smoothness Generated by a Generalized Dunkl operator on the Real Line

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Pure Mathematics 2015年第6期5卷 367-376页

作者： Reem Fahad Al Subaie Mohamed Ali Mourou Department of Mathematics College of Sciences for Girls University of Dammam Dammam Kingdom of Saudi Arabia Department of Mathematics Faculty of Sciences of Monastir University of Monastir Monastir Tunisia

This paper is intended to establish the equivalence between K-functionals and modulus of smoothness tied to a Dunkl type operator on the real line.

关键词： Differential-Difference operator Generalized Fourier Transform Generalized Translation operators K-Functionals Modulus of Smoothness

Characterization of Periodic Eigenfunctions of the Fourier Transform operator

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

American Journal of Computational Mathematics 2013年第4期3卷 304-312页

作者： Comlan de Souza David W. Kammler Department of Mathematics California State University at Fresno Fresno USA Department of Mathematics Southern Illinois University at Carbondale Carbondale USA

We generalize this result to p1,p2-periodic eigenfunctions of F?on R2 and to p1,p2,p3-periodic eigenfunctions of F?on R3.

关键词： Eigenfunction Fourier Transform operator