斯特互尔特定理及其应用

在平面几何中,大凡每一个定理都相应地揭示出它所对应图形内在的性质与规律.本文仅以斯特瓦尔特定理为例,利用它来解决一类难度较大的几何命题间的数量关系的证明题,一展它在证题中的风采.一、斯特瓦尔特(Stewart)定理及其证明     

次线性期望下的一般中心极限定理

受Peng-中心极限定理的启发,本文主要应用G-正态分布的概念,放宽Peng-中心极限定理的条件,在次线性期望下得到形式更为一般的中心极限定理.首先,将均值条件E[X_n]=ε[X_n]=0放宽为|E[X_n]|+|ε[X_n]|=O(1/n);其次,应用随机变量截断的方法,放宽随机变量的2阶矩与2+δ阶矩条件;最后,将该定理的Peng-独立性条件进行放宽,得到卷积独立随机变量的中心极限定理.     

Banach空间中的广义隐补问题

在Banach空间中引入了广义隐补问题的概念,并证明了广义隐补问题解的存在性定理.     

一道数学竞赛题的讨论

对浙江省大学生数学竞赛题的一道试题从试题结论的推广及新的结论等方面进行了讨论.     

一道数学竞赛试题的多种解法

对第九届中国大学生数学竞赛预赛(数学类)的一道试题又给出了两种解法,有助于拓宽解题思路.     

Taylor公式课堂教学的设计与探索

在多年教学经验的基础上,探讨泰勒公式的教学设计,结合动图演示,采取启发式教学,着力引导学生理解泰勒公式的引入和推导,渗透化繁为简的核心思想,帮助学生掌握好这一重要工具.     

Fixed points of multivalued quasi-nonexpansive mappings using a faster iterative process

In this article, we prove some strong and weak convergence theorems for quasi-nonexpansive multivalued mappings in Banach spaces. The iterative process used is independent of Ishikawa iterative process and converges faster. Some examples are provided to validate our results. Our results extend and unify some results in the contemporary literature.     

“组装法”证明对称不等式

随着科技的进步,如今大型桥梁、地铁等都是采用分段施工、整体合拢的“组装”建造模式.其实,在解决数学问题时,尤其是证明那些外形结构相似的对称(或对称轮换)不等式,也可以借鉴上述模式:先精心分割成对称的局部,紧盯整体的目标和方向,最后有机融合于一体,我们把这种方法称为“组装法”.1.几个案例     

Effect of Time Delay on Binary Signal Detection via a Bistable System

The effect of time delay on binary signal detection via a bistable system in the presence of white or colored Gaussian noise is investigated. By defining the bit error rate based on the solution of the approximated Fokker- Planck equation, the detector performance is investigated theoretically and is verified by Monte Carlo simulation. It is shown that, when the system parameter or noise intensity is optimally chosen, the increasing time delay generally improves the system performance. It is also shown that it is more difficult to accurately predict the system performance with a larger time delay and correlation time. This may inspire more thorough investigations in cooperative effects of a nonlinear system and time delay on signal processing.