从Bergman空间到Bloch空间的叠加算子

研究从Bergman空间到Bloch空间的叠加算子.从函数空间的性质出发,利用不同维数的函数空间之间的关系,讨论叠加算子,把单变量有关叠加算子的结果推广到多变量,得到了与单变量一致的结果,从而刻画了从Bergman空间到Bloch空间的叠加算子的特征,得到了从Bergman空间到Bloch空间的叠加算子的充要条件.     

利率期限结构与宏观经济变量的相互关系研究

本文研究了利率期限结构与宏观经济变量之间的相互关系。运用利率期限结构与宏观经济变量的无套利模型,对向量自回归模型进行了扩展,将其引入到状态空间模型框架中,基于卡尔曼滤波并结合EM算法对模型参数进行了有效估计,结合实际数据对利率期限结构与宏观经济变量的相互影响关系进行了实证研究。结果表明:利率期限结构与宏观经济变量的双向影响关系显著;宏观经济变量对利率期限结构具有一定的解释力;研究利率期限结构时,宏观经济变量的影响作用不能忽略。     

几何流方程的分离变量解

利用不变子空间方法及拟设法,在变量变换作用下给出双曲几何流和Ricci流的各种分离变量解,包括乘法分离变量解和广义泛函分离变量解,并给出了这些解的性质分析.     

基于贝叶斯法则的空间自相关误差自相关模型变量选择研究

本文将研究贝叶斯法则视角下的空间自相关误差自相关模型(Spatial Autoregressive Model with Autoregressive Disturbances,SARAR模型)变量选择问题。通过将基于BIC准则的子集选择法推广到空间模型,实现SARAR模型的变量选择,并证明在一定条件下,对于SARAR模型的变量选择BIC准则具有良好的渐近性质。同时本文还将利用Monte Carlo模拟验证BIC准则能够很好的实现SARAR模型的变量选择。最后以股票收益率为例,在验证股票收益率具有空间效应的前提下,利用BIC准则对影响股票收益率的众多财务指标进行变量选择。     

A元不变量及其复合

在一个变换群下有许多的变换不变量,同时也有任意元的不变量或称为A元不变量,本文提出基于A元不变量,使所有的A元不变量都可以则基本A元不变量复合而成,证明A元基本不变量是存在的;给同一个充分必要条件,用于判定不变量的基本性,还对欧氏空间中各种常见变换群下的基本不变量进行稳定。     

具有变量核Marcinkiewicz积分交换子的CBMO估计

本文讨论了当b∈CBMO_q(R~n)时,具有变量核的Marcinkiewicz积分交换子μ_(Ω,b)在Herz空间和Herz型Hardy空间中的有界性.     

广义Morrey空间上的奇异积分多线性交换子

本文得到了具有混合齐次变量核的奇异积分算子的多线性交换子在广义Morrey空间和加权Lebesgue空间上的有界性.     

广义Morrey空间上的奇异积分多线性交换子

本文得到了具有混合齐次变量核的奇异积分算子的多线性交换子在广义Morrey空间和加权 Lebesgue空间上的有界性．     

Carnot-Caratheodory空间中的变换论

Klein发表著名的埃尔兰根纲领,由群论角度研究了空间变换群的不变量,从而引进了各种不同的几何学．本文利用Felix Klein的观念,研究Carnot-Caratheodory空间{M,Q,g}(又称为次黎曼流形)上的类似问题,给出了次黎曼流形中的共形不变量和射影不变量．本文给出的共形和射影不变量可视为黎曼情形的一种自然推广．由于次黎曼流形与黎曼流形之间有着本质的差异,故此,本文通过次黎曼流形上存在的唯一非完整联络(Nonholonomic connections)来刻画所提的问题．     

基于模式的建模与自适应控制

针对一类复杂生产过程,提出了一种利用模式的运动来描述系统动力学特性与控制的新方法.方法不同于传统的如输出方程或状态空间模型等建模方法.首先根据实际工况数据利用聚类算法来获得工况模式类别的划分,以这些类别作为空间刻度构造"模式运动空间".然后在此空间上定义描述模式运动的变量~模式类别变量,并建立了基于模式类别变量的预测模型及控制模型,给出了基于模式类别变量的自适应控制方法.最后根据安阳钢铁厂400烧结机的实际工况数据进行了仿真,取得了满意的结果,验证了该种方法的可行性.     

Cost-effective modeling strategies for the analysis of spliced steel connections

The paper presents several cost-effective modeling strategies that can be used by structural engineers in practice to determine the stresses in the spliced members. The computational efficiency and the modeling effort required for the several modeling options are also discussed. The deformation mechanisms and load transfer for several types of connections are illustrated. Optimization techniques are also presented to economize the computer time for connections with large number of bolts. Results are presented to compare the accuracy of several modeling strategies commonly used in practice. It is shown that for eccentric connections, the flexural bending largely affect the maximum tensile and compressive stresses within the joint. The difference may reach up to 54%. Finally, Experimental comparisons are made with the numerical procedures for typical connection model.     

Oscillation criteria of neutral type impulsive hyperbolic equations

In this paper, oscillatory properties of all solutions for neutral type impulsive hyperbolic equations with several delays under the Robin boundary condition are investigated and several new sufficient conditions for oscillation are presented.     

非线性脉冲中立型双曲方程的振动性

讨论非线性时滞脉冲中立型双曲方程的振动性质,利用平均值方法以及泛函微分不等式获得了该类方程在一类非线性边值条件下所有解振动的充分判据.结果表明,振动是由滞量和脉冲引起的.     

OSCILLATION CRITERIA OF NEUTRAL TYPE IMPULSIVE HYPERBOLIC EQUATIONS

In this paper, oscillatory properties of all solutions for neutral type impulsive hyperbolic equations with several delays under the Robin boundary condition are investigated and several new sufficient conditions for oscillation are presented.     

Lower and upper bounds for characteristic functions

In the paper, several known inequalities for characteristic functions are sharpened and several new ones are derived. Proceedings of the XVII Seminar on Stability Problems for Stochastic Models, Kazan, Russia, 1995, Part III.     

A hybrid genetic algorithm for the container loading problem

This paper presents a hybrid genetic algorithm (GA) for the container loading problem with boxes of different sizes and a single container for loading. Generated stowage plans include several vertical layers each containing several boxes. Within the procedure, stowage plans are represented by complex data structures closely related to the problem. To generate offspring, specific genetic operators are used that are based on an integrated greedy heuristic. The process takes several practical constraints into account. Extensive test calculations including procedures from other authors vouch for the good performance of the GA, above all for problems with strongly heterogeneous boxes.     

含多个任意参数的广义变分原理及换元乘子法

弹性力学变分原理的泛函变换可分为三种格式:Ⅰ、放松格式,Ⅱ、增广格式,Ⅲ、等价格式. 根据格式Ⅲ,提出含多个任意参数的广义变分原理及其泛函表示式,其中包括:以位移u为一类泛函变量的多参数广义变分原理;以位移u和应力σ为二类泛函变量的多参数广义变分原理;以位移u和应变ε为二类泛函变量的多参数广义变分原理;以位移u应变ε和应力σ为三类泛函变量的多参数广义变分原理.由这些原理可得出等价泛函一系列新形式,此外,通过参数的合理选择,可构造出一系列有限元模型. 本文还讨论了拉氏乘子法“失效”问题,指出“失效”现象产生的原因,提出乘子法“恢复有效”的作法——换元乘子法.     

与积分有关的一个极限及其应用

将崔尚斌编著的《数学分析教程》(中册)的一个综合习题进行推广,得到求与积分有关的极限的几个实用性结果,并给出多个应用例子.     

Computing the spectral function for singular Sturm–Liouville problems

Algorithms for computing Sturm–Liouville spectral density functions are developed based on several mathematical characterizations. Convergence and error bounds are derived and methods are tested on several examples. The results are compared with those from the existing software package SLEDGE.     

Elementary variational approach to zero-free solutions of a nonlinear eigenvalue problem

A variational approach is employed for obtaining zero-free solutions of a nonlinear eigenvalue problem that appears in several recent studies. Our proofs are elementary but our results are sharp and yield corrections to several existing assertions in the literature.