共查询到20条相似文献，搜索用时 843 毫秒
1.
徐洪国 《上海大学学报(英文版)》2004,8(4):391-396
We present a numerical method for solving the indefinite least squares problem. We first normalize the coefficient matrix,Then we compute the hyperbolic QR factorization of the normalized matrix. Finally we compute the solution by solving several trian-gular systems. We give the first order error analysis to show that the method is backward stable. The method is more efficient thanthe backward stable method proposed by Chandrasekaran, Gu and Sayed. 相似文献
2.
Finite element reliability analysis of slope stability 总被引：1，自引：0，他引：1
The method of nonlinear finite element reliability analysis （FERA） of slope stability using the technique of slip surface stress analysis （SSA） is studied. The limit state function that can consider the direction of slip surface is given, and the formulations of FERA based on incremental tangent stiffness method and modified Aitken accelerating algorithm are developed. The limited step length iteration method （LSLIM） is adopted to calculate the reliability index. The nonlinear FERA code using the SSA technique is developed and the main flow chart is illustrated. Numerical examples are used to demonstrate the efficiency and robustness of this method. It is found that the accelerating convergence algorithm proposed in this study proves to be very efficient for it can reduce the iteration number greatly, and LSLIM is also efficient for it can assure the convergence of the iteration of the reliability index. 相似文献
3.
SUNG Wen-pei GO Cheer-germ SHIH Ming-hsiang 《浙江大学学报(A卷英文版)》2007,8(9):1373-1379
The characteristic properties of shell element with similar shapes are used to generate a so-called super element for the analysis of the crack problems for cylindrical pressure vessels. The formulation is processed by matrix condensation without the involvement of special treatment. This method can deal with various singularity problems and it also presents excellent results to crack problems for cylindrical shell. Especially,the knowledge of the kind of singular order is not necessary in super element generation; it is very economical in terms of computer memory and programming. This method also exhibits versatility to solve the problem of kinked crack at cylindrical shell. 相似文献
4.
Based on the predictor corrector, we developed a new improved gradient method named the predictor corrector gradient algorithm (PCGM), which is useful for solving linear equations with symmetric positive definite of coefficient matrix.To improve the speed of convergence of traditional gradient method, we let values of original iterative formula be viewed as forecast values.Meanwhile, they are corrected by a new iterative formula through introducing corresponding step parameter.Therefore, a feasible and efficient algorithm is constructed.Numerical experiments indicate that PCGM method not only improve the accuracy and the speed of convergence, but also greatly reduce the number of steps to converge.The simple algorithm is easy to be realized and operated. 相似文献
5.
We derive necessary and sufficient conditions for the existence and an expression of the （anti）reflexive solution with respect to the nontrivial generalized reflection matrix P to the system of complex matrix equations AX = B and XC = D. The explicit solutions of the approximation problem min x∈Ф ｜｜X - E｜｜F was given, where E is a given complex matrix and Ф is the set of all reflexive （or antireflexive） solutions of the system mentioned above, and ｜｜·｜｜ is the Frobenius norm. Furthermore, it was pointed that some results in a recent paper are special cases of this paper. 相似文献
6.
A meshless local discontinuous Petrov-Galerkin (MLDPG) method based on the local symmetric weak form (LSWF) is presented with the application to blasting problems. The derivation is similar to that of mesh-based Runge-Kutta Discontinuous Galerkin (RKDG) method. The solutions are reproduced in a set of overlapped spherical sub-domains, and the test functions are employed from a partition of unity of the local basis functions. There is no need of any traditional non-overlapping mesh either for local approximation purpose or for Galerkin integration purpose in the presented method. The resulting MLDPG method is a meshless, stable, high-order accurate and highly parallelizable scheme which inherits both the advantages of RKDG and meshless method (MM), and it can handle the problems with extremely complicated physics and geometries easily. Three numerical examples of the one-dimensional Sod shock-tube problem, the blast-wave problem and the Woodward-Colella interacting shock wave problem are given. All the numerical results are in good agreement with the closed solutions. The higher-order MLDPG schemes can reproduce more accurate solution than the lower-order schemes. 相似文献
7.
Due to historic reasons China encounters some special difficulties in ESI(electricity system industry) restructureing,An easy and simple electricity value equivalent(es-EVE) method for day-ahead pool purchase pricing of China is therefore presented in this paper.The es-EVE method is different from two-part and one-part tariffs.It is more like the UK‘s method in form,but revised for China with some new concepts and procedure.The main contributions of it include:(1) Find two kinds of eigenvalue,namely EVEs,in an optimization model.(2) Define new concepts of virtual units units and feasible region,(3) Twice merit orderings are employed successively to find marginal price.They are simple maximum and minimum comparison procedures and so on.The special economic significance of the method for China is discussed.and some suggestion for ESI Restructuring based on es-EVE method are provided.A case study is offered at the end of the paper. 相似文献
8.
The seed method is used for solving multiple linear systems A^(i) x^(i) = b^(i) for l≤ i≤ s , where the coefficient matrix A^(i) and the right-hand side b^(i) are different in general. It is known that the CG method is an effective method for symmetric coefficient matrices A^(i) . In this paper, the FOM method is employed to solve multiple linear systems when coefficient matrices are non-symmetric matrices. One of the systems is selected as the seed system which generates a Krylov subspace, then the residuals of other systems are projected onto the generated Krylov subspace to get the approximate solutions for the unsolved ones. The whole process is repeated until all the systems are solved. 相似文献
9.
As a basic mathematical structure,the system of inequalities over symmetric cones and its solution can provide an effective method for solving the startup problem of interior point method which is used to solve many optimization problems.In this paper,a non-interior continuation algorithm is proposed for solving the system of inequalities under the order induced by a symmetric cone.It is shown that the proposed algorithm is globally convergent and well-defined.Moreover,it can start from any point and only needs to solve one system of linear equations at most at each iteration.Under suitable assumptions,global linear and local quadratic convergence is established with Euclidean Jordan algebras.Numerical results indicate that the algorithm is efficient.The systems of random linear inequalities were tested over the second-order cones with sizes of 10,100,,1 000 respectively and the problems of each size were generated randomly for 10 times.The average iterative numbers show that the proposed algorithm can generate a solution at one step for solving the given linear class of problems with random initializations.It seems possible that the continuation algorithm can solve larger scale systems of linear inequalities over the secondorder cones quickly.Moreover,a system of nonlinear inequalities was also tested over Cartesian product of two simple second-order cones,and numerical results indicate that the proposed algorithm can deal with the nonlinear cases. 相似文献
10.
The convergence criterion of Newton’s method to find the zeros of a map f from a Lie group to its corresponding Lie algebra is established under the assumption that f satisfies the classical Lipschitz condition, and that the radius of convergence ball is also obtained. Furthermore, the radii of the uniqueness balls of the zeros of f are estimated. Owren and Welfert (2000) stated that if the initial point is close sufficiently to a zero of f, then Newton’s method on Lie group converges to the zero; while this paper provides a Kantorovich’s criterion for the convergence of Newton’s method, not requiring the existence of a zero as a priori. 相似文献
11.
谭云 《青岛职业技术学院学报》2007,20(3):71-73
本文给出了计算结构J-对称矩阵特征值的算法。这些算法以Van Loan的平方约化方法和Cullum与Willoughby提出的计算复对称三对角矩阵特征值的QL过程为基础,利用了J-对称矩阵的特殊结构,可以节省计算量和存储量。 相似文献
12.
在给定部分特征值、部分特征向量及附加条件下提出了一类反问题,并给出了此问题解存在性的证明。 相似文献
13.
讨论非负三对角矩阵的性质,给出与其逆有相同零位模式的三对角矩阵的条件,研究了该矩阵为逆M-矩阵的条件,间接地给出了非负三对角矩阵为逆M-矩阵的充分必要条件. 相似文献
14.
丁瑶 《重庆职业技术学院学报》2009,18(2):120-123
本文介绍了几种求实对称矩阵尤其是实对称三对角矩阵特征值问题的方法,并且针对几类求法给出了具体的实现步骤。最后在对这几种比较求法的比较中,主要研究了各类方法的优越性。 相似文献
15.
文章统一了三对角行列式的具体表达式；通过对分块轮接矩阵知识的用运，给出了更一般的分块三对角行列式的表达式，推广了前人的一些结果，便于计算机实现，时间复杂度为O（nlog2n)。 相似文献
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17.
本文讨论了SAOR迭代方法的收敛性问题.得到了当系数矩阵为对角元素非零的相容次序矩阵,且Jacobi迭代矩阵的特征值都是纯虚数时SAOR方法收敛的充要条件. 相似文献
18.
The authors argue that skills in quantitative literacy (QL) and quantitative reasoning (QR) augment students’ communicative effectiveness. This article offers a pedagogical framework and model for how QR can be productively interwoven with the rhetorical know-how of technical writing pedagogy. The authors describe their course redesign, present preliminary assessment data, and conclude by highlighting some implications not only for student learning, but also for the QL movement itself. 相似文献
19.
三对角对称正定阵及三对角对称M阵的逆特征值问题 总被引：1，自引：0，他引：1
廖安平 《邵阳学院学报(社会科学版)》1994,(2)
本文研究了由两个特征值和相应的特证向量构造三对角对称正定阵和三对角对称M阵等二类逆特征值问题,给出了这两类逆特征值问题有解的充要条件及通式。 相似文献
20.
康艳艳 《西安文理学院学报》2010,13(2):44-49
块Jacobi—Davidson方法是求解对称矩阵重或密集特征值问题的一种有效方法．为了提高其整体收敛速度,应用动态压缩技术,提出了动态压缩的块Jacobi—Davidson方法;为了计算大型对称矩阵的内部特征对,本文将调和Rayleigh—Ritz方法与块Jacobi—Davidson方法结合,提出了调和块Jacobi—Davidson方法,并将动态压缩技术应用于调和块Jacobi—Davidson方法,给出了动态压缩的调和块Jacobi—Davidson方法．数值结果表明,动态压缩的块Jacobi—Davidson方法优于块Jacobi—David—son方法,动态压缩的调和块Jacobi—Davidson方法能有效计算大型对称矩阵的内部重或密集特征值． 相似文献