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排序方式: 共有5784条查询结果,搜索用时 15 毫秒
971.
消费者不确定性的测度——基于异方差的视角 总被引:2,自引:0,他引:2
预防性储蓄理论的核心是对消费者不确定的测度.认为异方差是不确定性的很好代理变量.本文以极大似然法估计异方差,并运用消费者家计抽样调查数据,讨论收入和支出的异方差对消费者行为的影响. 相似文献
972.
In this paper, the Fourier collocation method for solving the generalized Benjamin-Ono equation with periodic boundary conditions is analyzed. Stability of the semi-discrete scheme is proved and error estimate in H1/2-norm is obtained. 相似文献
973.
L^p- L^q decay estimate of solution to Cauchy problem of a linear thermoviscoelastic system is studied. By using a diagonalization argument of frequency analysis, the coupled system will be decoupled micrologically. Then with the help of the information of characteristic roots for the coefficient matrix of the system, L^p- L^q decay estimate of parabolic type of solution to the Cauchy problem is obtained. 相似文献
974.
在严格凸且具有一致Gâteaux可微范数的Banach空间$E$框架内, 该文借助于两种粘滞逼近算法去近似逼近关于弱压缩算子的变分不等式解并且也获得了相应的收敛率估计. 相似文献
975.
一类新的非单调记忆梯度法及其全局收敛性 总被引:1,自引:0,他引:1
在非单调Armijo线搜索的基础上提出一种新的非单调线搜索,研究了一类在该线搜索下的记忆梯度法,在较弱条件下证明了其全局收敛性。与非单调Armijo线搜索相比,新的非单调线搜索在每次迭代时可以产生更大的步长,从而使目标函数值充分下降,降低算法的计算量。 相似文献
976.
977.
The numerical solution of linear elliptic partial differential equations most often involves a finite element or finite difference
discretization. To preserve sparsity, the arising system is normally solved using an iterative solution method, commonly a
preconditioned conjugate gradient method. Preconditioning is a crucial part of such a solution process. In order to enable
the solution of very large-scale systems, it is desirable that the total computational cost will be of optimal order, i.e.
proportional to the degrees of freedom of the approximation used, which also induces mesh independent convergence of the iteration.
This paper surveys the equivalent operator approach, which has proven to provide an efficient general framework to construct
such preconditioners. Hereby one first approximates the given differential operator by some simpler differential operator,
and then chooses as preconditioner the discretization of this operator for the same mesh. In this survey we give a uniform
presentation of this approach, including theoretical foundation and several practically important applications for both symmetric
and nonsymmetric equations and systems, and some nonlinear examples in the context of Newton linearization.
Dedicated to the memory of Gene Golub for his friendly manner and for his broad interest and significant impact on numerical
analysis. 相似文献
978.
Zdeněk Strakoš 《Numerical Algorithms》2009,51(3):363-379
Given a nonsingular complex matrix and complex vectors v and w of length N, one may wish to estimate the quadratic form w
*
A
− 1
v, where w
* denotes the conjugate transpose of w. This problem appears in many applications, and Gene Golub was the key figure in its investigations for decades. He focused
mainly on the case A Hermitian positive definite (HPD) and emphasized the relationship of the algebraically formulated problems with classical
topics in analysis - moments, orthogonal polynomials and quadrature. The essence of his view can be found in his contribution
Matrix Computations and the Theory of Moments, given at the International Congress of Mathematicians in Zürich in 1994. As in many other areas, Gene Golub has inspired
a long list of coauthors for work on the problem, and our contribution can also be seen as a consequence of his lasting inspiration.
In this paper we will consider a general mathematical concept of matching moments model reduction, which as well as its use in many other applications, is the basis for the development of various approaches for estimation
of the quadratic form above. The idea of model reduction via matching moments is well known and widely used in approximation
of dynamical systems, but it goes back to Stieltjes, with some preceding work done by Chebyshev and Heine. The algebraic moment matching problem can for A HPD be formulated as a variant of the Stieltjes moment problem, and can be solved using Gauss-Christoffel quadrature. Using
the operator moment problem suggested by Vorobyev, we will generalize model reduction based on matching moments to the non-Hermitian
case in a straightforward way. Unlike in the model reduction literature, the presented proofs follow directly from the construction
of the Vorobyev moment problem.
The work was supported by the GAAS grant IAA100300802 and by the Institutional Research Plan AV0Z10300504. 相似文献
979.
In this paper we consider a class of second-kind singular integral equations with Hilbert kernel on the unit circumference. We theoretically substantiate a solution method based on an interpolation-type operator. 相似文献
980.
In this paper we develop and study a new stabilized finite volume method for the two-dimensional Stokes equations. This method
is based on a local Gauss integration technique and the conforming elements of the lowest-equal order pair (i.e., the P
1–P
1 pair). After a relationship between this method and a stabilized finite element method is established, an error estimate
of optimal order in the H
1-norm for velocity and an estimate in the L
2-norm for pressure are obtained. An optimal error estimate in the L
2-norm for the velocity is derived under an additional assumption on the body force.
This work is supported in part by the NSF of China 10701001 and by the US National Science Foundation grant DMS-0609995 and
CMG Chair Funds in Reservoir Simulation. 相似文献