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71.
72.
加速牛顿迭代收敛的新方法 总被引:2,自引:0,他引:2
提出了加速牛顿迭代收敛的新思想,构造出一类加权牛顿迭代格式,通过选取最优加权因子,使得该格式具有高阶收敛性和较小的渐近误差常数。 相似文献
73.
The problem of obtaining inner approximations to the set
of null controllability for linear systems is considered, and the geometry of certain sets arising in the approximation of
using linear feedback is explored. A two-dimensional example is worked in detail in order to delineate the limitations to the use of linear feedback. 相似文献
74.
Sze-Man Tse 《Annals of the Institute of Statistical Mathematics》2006,58(4):675-686
In this paper, we consider a nonparametric estimator of the Lorenz curve and Gini index when the data are subjected to random
left truncation and right censorship. Strong Gaussian approximations for the associated Lorenz process are established under
appropriate assumptions. A law of the iterated logarithm for the Lorenz curve is also derived. Lastly, we obtain a central
limit theorem for the corresponding Gini index. 相似文献
75.
M.?-G.?PorquetEmail author S.?Péru M.?Girod 《The European Physical Journal A - Hadrons and Nuclei》2005,25(3):319-323
Self-consistent calculations using the D1S Gogny force have been performed in order to study the mechanism involved in the
crossing of the πd
5/2 and πg
7/2 orbitals in the Sb isotopes. This inversion is well predicted by the HFB + blocking calculations with spherical symmetry
performed for the odd-A Sb isotopes. In addition, several HFB and HF calculations have been performed for even-even nuclei of the five neighbouring
isotopic chains (Z = 46 to 54, from the proton dripline to N = 82). The results obtained for the binding energies of the two proton orbitals indicate that the radii of the systems play
an important role in the crossing, even though some particular πν interactions also give a contribution. The spin-orbit interaction,
which is known to be concentrated mainly at the nuclear surface, is proposed to be the main responsible of the crossing. 相似文献
76.
The Ostrowski theorem is a classical result which ensures the attraction of all the successive approximations x
k+1 = G(x
k
) near a fixed point x*. Different conditions [ultimately on the magnitude of G(x*)] provide lower bounds for the convergence order of the process as a whole. In this paper, we consider only one such sequence and we characterize its high convergence orders in terms of some spectral elements of G(x*); we obtain that the set of trajectories with high convergence orders is restricted to some affine subspaces, regardless of the nonlinearity of G. We analyze also the stability of the successive approximations under perturbation assumptions. 相似文献
77.
78.
A New Higher Order Shear Deformation Model for Static Behavior of Functionally Graded Plates 下载免费PDF全文
Tahar Hassaine Daouadji Abdelouahed Tounsi & El Abbes Adda Bedia 《advances in applied mathematics and mechanics.》2013,5(3):351-364
In this paper, a new displacement based high-order shear deformation theory is introduced
for the static response of functionally graded plate. Unlike any other theory, the number
of unknown functions involved is only four, as against five in case of other shear deformation
theories. The theory presented is variationally consistent, has strong similarity with
classical plate theory in many aspects, does not require shear correction factor, and
gives rise to transverse shear stress variation such that the transverse shear stresses
vary parabolically across the thickness satisfying shear stress free surface conditions.
The mechanical properties of the plate are assumed to vary continuously in the thickness
direction by a simple power-law distribution in terms of the volume fractions of the
constituents. Numerical illustrations concerned flexural behavior of FG plates with
Metal-Ceramic composition. Parametric studies are performed for varying ceramic volume
fraction, volume fraction profiles, aspect ratios and length to thickness ratios. The
validity of the present theory is investigated by comparing some of the present results
with those of the classical, the first-order and the other higher-order theories. It
can be concluded that the proposed theory is accurate and simple in solving the static
behavior of functionally graded plates. 相似文献
79.
Using a method of uniform approximations, necessary and sufficient conditions for a nonsmooth constrained vector-valued minimax problem are established in terms of Mordukhovich subdifferentials. 相似文献
80.
Qiang Ye 《Linear algebra and its applications》2008,428(4):911-918
We consider the problem of how to expand a given subspace for approximating an eigenvalue and eigenvector of a matrix A. Specifically, we consider which vector in the subspace, after multiplied by A, provides optimal expansion of the existing subspace for the eigenvalue problem. We determine the optimal vector, when the quality of subspace for approximation is measured by the angle between the subspace and the eigenvector. We have also derived some characterization of the angle that might lead to more practically useful choice of the expansion vector. 相似文献