一般端点条件下一类样条插值的唯一可解性与凸性或单调性

一般端点条件下3次样条插值的唯一可解性见[1]—[7]。在特殊类型端点条件下一些样条插直的凸性或单调性见[8]—[11]。本文则考虑一般端点条件下一类样条插值的唯一可解性与凸性或单调性。在唯一可解性方面把[1]—[7]中一些结果推广到其他类型样条插值,在凸性或单调性方面则把[8]—[11]中结果推广到一般端点条件。这类样条插值在一般端点条件下的唯一可解性与凸性或单调性归结为下列类型的线性方程组的唯一可解性与解的非负性:     

广义Kannan型压缩条件的注记

本文给出了 [4 ]中的广义Kannan型压缩条件下映象的一个不动点定理 ,说明了 [2 5]中广义Kannan型压缩条件下映象与 [1 ]中Kannan型压缩条件下映象具有一致的不动点存在性 .     

A-稳定秩下的酉K1-群

A.Bak和唐国平在[1]中引入了Λ-稳定秩条件,这是比过去常用的酉稳定秩条件与绝对稳定秩条件都要弱的新的稳定秩条件.利用这一稳定秩条件证明了酉群(有限生成投射模上二次型的自同构群)的基本子群的正规性、二次型空间的消去性、以及酉K1-群的稳定性.这些结果不仅推广了已有的类似结果、极大地简化了证明过程,而更重要的是降低了稳定秩的下界.     

Λ-稳定秩下的酉K_1-群

A.Bak和唐国平在[1]中引入了Λ-稳定秩条件,这是比过去常用的酉稳定秩条件与绝对稳定秩条件都要弱的新的稳定秩条件.利用这一稳定秩条件证明了酉群(有限生成投射模上二次型的自同构群)的基本子群的正规性、二次型空间的消去性.以及酉K1-群的稳定性.这些结果不仅推广了已有的类似结果、极大地简化了证明过程,而更重要的是降低了稳定秩的下界.     

Sturm-Liouville问题先验估计的改进

该文完全去掉了[1]中对Sturm-Liouville两点边值问题进行先验估计时,△为单点集这一条件,从而本质上改进了[1]中非平凡解的存在性定理.     

一类密度估计的r阶平均相合性

Prakasa Rao在文献 [1 ]中提出了一类密度估计 fn( x) .本文在一些较弱的条件下 ,研究 fn( x)逐点 r阶平均相合性和一致 r阶平均相合性     

结合环的若干交换性条件

作者在[1],[2]中讨论了结合环的一些交换性条件,本文继续[1],[2],进一步讨论半质环与 K(?)the 半单纯环的交换性条件.容易验证本文所讨论换性条件在环同态下是不变的,而半质环与 K(?)the 半单纯环分别是质环的次直和与 K(?)the 半单纯质环的次直和.所以我们只要证明满足相应条件的质环、K(?)the 半单纯质环是可换环,则它们对     

一类鞍点型线性半连续动力系统的周期解

讨论了一类鞍点型线性半连续动力系统,给出了阶1周期解存在性、唯一性、稳定性以及阶2周期解不存在性的条件,并指出在一定的条件下,系统可以存在无穷多个阶1周期解.最后给出了相应理论结果的数值模拟.     

弱序列式回缩(LM)-空间的特征

本文研究Retakh's条件(M_0),正则性和弱序列式回缩性之间的关系．对于(LM)-空间,弱序列式回缩性等价于正则性加上一个介于(Q_0)和(M_0)之间的条件对于(LN)-空间,我们获得了更满意的结果,证明了弱序列式回缩性等价于正则性加上条件(M_0),也等价于一个非常弱的正则性条件加上条件(M_0)(见文献[1-28])．     

Banach空间中非线性Volterra积分方程解的存在性和比较定理

本文以非紧致测度为工具,进一步研究了Banaeh空间中非线性Volterra积分方程解的存在性和比较结果,在解的存在性准则中我们取消了核函数的一致连续性这一实质性的条件,在极值解的存在性和比较结果中我们也对以往的结果做了许多改进(参见文[1-4]).     

Matrix representations of Sturm‐Liouville problems with coupled eigenparameter‐dependent boundary conditions and transmission conditions

We study matrix representations of Sturm‐Liouville problems with coupled eigenparameter‐dependent boundary conditions and transmission conditions. Meanwhile, given any matrix eigenvalue problem with coupled eigenparameter‐dependent boundary conditions and transmission conditions, we construct a class of Sturm‐Liouville problems with given boundary conditions and transmission conditions such that they have the same eigenvalues.     

Degenerate boundary conditions for the diffusion operator

We describe all degenerate two-point boundary conditions possible in a homogeneous spectral problem for the diffusion operator. We show that the case in which the characteristic determinant is identically zero is impossible for the nonsymmetric diffusion operator and that the only possible degenerate boundary conditions are the Cauchy conditions. For the symmetric diffusion operator, the characteristic determinant is zero if and only if the boundary conditions are falsely periodic boundary conditions; the characteristic determinant is identically a nonzero constant if and only if the boundary conditions are generalized Cauchy conditions.     

两邻接B样条曲面的G1连续条件

本文得到了非均匀重内节点邻接B样条曲面间G1连续的充要条件 ,给出了一类G1连续的充分条件 ;基于对B样条曲线参数连续性的分析 ,本文着重给出了这类充分条件成立的内在约束 ,即对公共边界控制顶点的约束条件 .     

Generalized boundary conditions on representative volume elements and their use in determining the effective material properties

We discuss generalized boundary conditions for representative volume elements (RVE), which include the classical boundary conditions as special cases. From the generalization, stochastic boundary conditions are derived. These allows to adjust the the stiffness of the boundary conditions smoothly between the extremal cases of homogeneous strain and homogeneous stress boundary conditions. We found that it needs to be distinguished between the resistance of the boundary conditions against homogeneous and inhomogeneous RVE deformation. The stochastic BC can combine the moderate stiffness of the well known periodic boundary conditions with the high resistance against localization of the homogeneous strain boundary conditions. (© 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

New bifurcation theorems via the second-order optimality conditions

We derive new sufficient conditions for bifurcation relying on subtle second-order necessary optimality conditions for abnormal equality-constrained optimization problems. We relate these conditions to the known ones, and demonstrate the cases when the new conditions are easier to verify.     

集值优化问题的高阶最优性条件(借助Studniarski导数)(英文)

本文研究的是约束集值优化问题的高价最优性条件.首先通过借助集值映射的Stud-niarski导数和严格局部有效性,讨论了集值优化问题的高阶必要条件和充分条件.对于充分条件,初始空间必须是有限维的.其次在初始空间和目标空间是有限维的以及集值映射是m阶稳定的条件下,也得到了此约束集值优化问题的高阶最优性条件.     

非全局Lipschitz条件下随机延迟微分方程Euler方法的收敛性

大多数随机延迟微分方程数值解的结果是在全局Lipschitz条件下获得的.许多延迟方程不满足全局Lipschitz条件,研究非全局Lipschitz条件下的数值解的性质,具有重要的意义.本文证明了漂移系数满足单边Lipschitz条件和多项式增长条件,扩散系数满足全局Lipschitz条件的一类随机延迟微分方程的Eul...     

Necessary Conditions for Nonsmooth,Infinite-Horizon,Optimal Control Problems

Necessary conditions are proved for deterministic nonsmooth optimal control problems involving an infinite horizon and terminal conditions at infinity. The necessary conditions include a complete set of transversality conditions.     

Geometric interpretation of the optimality conditions in multifacility location and applications

Geometrical optimality conditions are developed for the minisum multifacility location problem involving any norm. These conditions are then used to derive sufficient conditions for coincidence of facilities at optimality; an example is given to show that these coincidence conditions seem difficult to generalize.     

Necessary and sufficient conditions in constrained optimization

Additional conditions are attached to the Kuhn-Tucker conditions giving a set of conditions which are both necessary and sufficient for optimality in constrained optimization, under appropriate constraint qualifications. Necessary and sufficient conditions are also given for optimality of the dual problem. Duality and converse duality are treated accordingly.