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81.
讨论了关于斜对称双对角矩阵的特征值反问题.即:已知一个n阶斜对称双对角矩阵的特征值和两个n-1阶子矩阵的部分特征值,则可求得该矩阵.最后给出了数值例子. 相似文献
82.
基于系统空间结构的分析 ,给出了求解系统约当规范形广义特征向量的新方法 .与 [1 ]中给出的方法相比 ,本文的方法更简单直接 .最后举例说明了方法的应用 . 相似文献
83.
《TOP》1986,1(1):127-138
Summary Many estimating procedures are carried out with incomplete data by means of different types of EM algorithms. They allow us
to obtain maximum likelihood parameter estimates in classical inference and also estimates based on the posterior mode in
Bayesian inference. This paper analyzes in detail the spectral radii of the Jacobian matrices algorithm as a possible way
to evaluate convergence rates. The eigenvalues of such matrices are explicitly obtained in some cases and, in all of them,
a geometric convergence rate is, at least, guaranteed near the optimum. Finally, a comparison between the leading eigenvalues
of EM and direct and approximate EM-Bayes algorithms may suggest the efficiency of each case. 相似文献
84.
A new method for estimating bounds of eigenvalues 总被引:1,自引:0,他引:1
A new method for estimating the bounds of eigenvalues is presented. In order to show that the method proposed is as effective
as Qiu's, an undamping spring-mass system with 5 nodes and 5 degrees of freedom is given. To illustrate that the present method
can be applied to structures which cannot be treated by non-negative decomposition, a plane frame with 202 nodes and 357 beam
elements is given. The results show that the present method is effective for estimating the bounds of eigenvalues and is more
common than Qiu's.
Project supported by the National Natural Science Foundation (No. 19872028) and the Mechanical Technology Development Foundation
of China. 相似文献
85.
The linear stability of the linear Phan-Thien Tanner (PTT) fluid model is investigated for plane Poiseuille flow. The PTT model involves parameters that can be used to fit shear and extensional data, which makes it suitable for describing both polymer solutions and melts. The base flow is determined using a Chebyshev-tau method. The linear stability equations are also discretized using Chebyshev approximations to furnish a generalized eigenvalue problem. The spectrum is shown to comprise a continuous part and a discrete part. The theoretical and numerical results are validated for the UCM and Oldroyd-B models, which are special cases of the PTT model, by comparing with results in the literature. It is demonstrated that the linear PTT fluid is stable to infinitesimal disturbances with respect to the range of shear-thinning, extensional and elasticity parameters considered. The computational efficiency and accuracy of the numerical method are also investigated. 相似文献
86.
The dynamical behavior of multi-spot solutions in a two-dimensional domain Ω is analyzed for the two-component Schnakenburg
reaction–diffusion model in the singularly perturbed limit of small diffusivity ε for one of the two components. In the limit ε→0, a quasi-equilibrium spot pattern in the region away from the spots is constructed by representing each localized spot
as a logarithmic singularity of unknown strength S
j
for j=1,…,K at unknown spot locations x
j
∈Ω for j=1,…,K. A formal asymptotic analysis, which has the effect of summing infinite logarithmic series in powers of −1/log ε, is then used to derive an ODE differential algebraic system (DAE) for the collective coordinates S
j
and x
j
for j=1,…,K, which characterizes the slow dynamics of a spot pattern. This DAE system involves the Neumann Green’s function for the Laplacian.
By numerically examining the stability thresholds for a single spot solution, a specific criterion in terms of the source
strengths S
j
, for j=1,…,K, is then formulated to theoretically predict the initiation of a spot-splitting event. The analytical theory is illustrated
for spot patterns in the unit disk and the unit square, and is compared with full numerical results computed directly from
the Schnakenburg model.
相似文献
87.
主要研究随机矩阵逆特征值问题.特别是对称双随机矩阵和列随机矩阵逆特征值问题.对参考文献[1]与[2]的结论作了一些推广.并给出了—个数值例子. 相似文献
88.
S. Ramasubramanian 《Proceedings Mathematical Sciences》2008,118(2):161-182
2007 Abel prize has been awarded to S R S Varadhan for creating a unified theory of large deviations. We attempt to give a
flavour of this branch of probability theory, highlighting the role of Varadhan. 相似文献
89.
90.
导出了具有正定对称核的积分方程最小特征值的一个下界估计式,为此为基础,获得了相应特征值的一种算法。 相似文献