非光滑第二类Fredholm方程Collocation解的迭代──校正方法

本文对于一类具非光滑核第二类Ｆｒｅｄｈｏｌｍ方程的Ｃｏｌｌｏｃａｔｉｏｎ解提出一种迭代─校正方法，使得在计算量增加很少的前提下，成倍提高逼近解精度，并将此方法用于平面多角域上边界积分方程，从而给出其相应微分方程逼近解的高精度算法。此方法还是一种自适应方法。     

平面上含鞍结点与中心型鞍点的余维3环的三参数开折

本文应用有限光滑正规形理论研究了含有一个重数为2的鞍结点与一个中心型双曲鞍点（双曲比率为1）的余维3的平面环（Polycycle）的一般三参数开折与环性,证明了这类环至多分支出三条极限环,并且在一般性条件下环性为3,给出了分支图和相应的相图．作为应用,证明了文［4］提出的图（I192）环性为1的猜想．     

一个与Dedekind和相关的新和式及其在特殊点的值

本文利用正整数模q的正则数的定义以及解析方法研究一类与Dedekind和有关的和式的计算问题,并给出这个和式在一些特殊点上有趣的恒等式.     

Solution of non-linear Fredholm integral equations of the first kind using modified homotopy perturbation method

In this paper, we present a modification to homotopy perturbation method for solving some non-linear Fredholm integral equations of the first kind. Solved problems reveal that the proposed method is very effective and simple and in some cases it gives the exact solution rather than the approximated one.     

一类证券市场中投资组合及消费选择的最优控制问题

研究一类证券市场中投资组合及消费选择的最优控制问题．在随机干扰源相互关联情形下,运用动态规划方法,对一类典型的效用函数CRRA(Constant Relative Risk Aversion,常数相对风险厌恶)情形,得到了最优投资组合及消费选择的显式解,并给出了最优解的经济解释和关于部分参数的灵敏度分析．     

Value functions and error bounds of trust region methods

This paper studies some properties of the value functions and gives some sufficient and necessary conditions about the presented global error and local error. And it leads to one kind of relationship between iterative points and optimal solution or K-T point.     

三对角矩阵的特征值及其应用

给出了计算一种三对角矩阵的特征值和特征向量的公式.利用矩阵的特征值理论证明了一些三角恒等式,特别是一些与Fibonacci数和第二类Chebyshev多项式有关的三角恒等式.     

Numerical method for solving linear Fredholm fuzzy integral equations of the second kind

In this paper we use parametric form of fuzzy number and convert a linear fuzzy Fredholm integral equation to two linear system of integral equation of the second kind in crisp case. We can use one of the numerical method such as Nystrom and find the approximation solution of the system and hence obtain an approximation for fuzzy solution of the linear fuzzy Fredholm integral equations of the second kind. The proposed method is illustrated by solving some numerical examples.     

一种磨光微分方法

本文讨论一种利用磨光思想求解微分的正则化方法，并讨论了它在某种条件下的收敛性．这种磨光微分方法结合正则化参数的选取得到了最优的收敛阶，最后给出了一个数值例子，证明该方法是可行的．     

一类Stefan问题的渐近解

本文讨论了一类具有一般初值条件的Stefan问题.把研讨论板分成三部份,每一部份选用不同的时间尺度,然后用PLK方法或类多重尺度法求得每一部份的渐近解.最后,就此解进行了讨论并得出相应的结论.     

On the Spectra of Striped Sign Patterns

Sign patterns consisting of some positive and some negative columns, with at least one of each kind, are shown to allow any self-conjugate spectrum, and thus to allow any inertia. In the case of the n ×n sign pattern with all columns positive, given any self-conjugate multiset consisting of n -1 complex numbers supplemented by a sufficiently large positive number, it is shown how to construct a positive normal matrix whose spectrum is this multiset. Thus, the positive sign pattern allows any inertia with at least one positive eigenvalue.     

On the Spectra of Striped Sign Patterns

Sign patterns consisting of some positive and some negative columns, with at least one of each kind, are shown to allow any self-conjugate spectrum, and thus to allow any inertia. In the case of the n × n sign pattern with all columns positive, given any self-conjugate multiset consisting of n m 1 complex numbers supplemented by a sufficiently large positive number, it is shown how to construct a positive normal matrix whose spectrum is this multiset. Thus, the positive sign pattern allows any inertia with at least one positive eigenvalue.     

Complete submanifolds of manifolds of negative curvature

In this article, we give sufficient conditions for a complete non-compact submanifold in a simply connected manifold of negative sectional curvature to have only one end. We also prove some Liouville theorems for harmonic maps from the same kind of submanifolds to manifolds of non-positive curvature.     

Behavior of Trajectories of Time-Invariant Systems

Finitely many embedded localizing sets are constructed for invariant compact sets of a time-invariant differential system. These localizing sets are used to divide the state space into three subsets, the least localizing set and two sets called sets of the first kind and the second kind. We prove that the trajectory passing through a point of the set of the first kind remains in this set and tends to infinity. For a trajectory passing through a point of the set of the second kind, there are three possible types of behavior: it either goes to infinity or, at some finite time, enters the least localizing set, or has a nonempty ω-limit set contained in the intersection of the boundary of one of the constructed localizing sets with the universal section of the corresponding localizing function.     

一类特殊非齐次树上二重马尔可夫链的若干强极限定理

极限定理一直是国际概率论界研究的中心课题之一.通过构造适当的辅助非负鞅而给出了一类特殊非齐次树上二重马尔可夫链的若干强极限定理.     

Webs with rotation and reflection properties and their relations with certain loops

In a web one can define in a natural way reflections in generators and a kind of rotations in points. The structure of the webs and the corresponding loops in which some of these maps are automorphisms will be studied in a synthetic way.     

无穷维Hilbert空间上框架的算子与范数

在框架理论研究中,哪类可逆算子能使得某些框架性质保持不变这个问题是基本和重要的,本文在无穷维Hilbert空间上对下述两个问题进行研究.问题1:哪类可逆算子能使得框架算子保持不变;问题2:哪类可逆算子能使得框架范数只相差一列常数.本文从抽象的算子理论和具体的构造方法两方面对问题1给出解答.利用框架的相容算子的概念,当把问题2中的可逆算子集换成一类较小的算子集时,得到了问题2的回答.     

模糊互补判断矩阵的一个通用排序公式及其保序性研究

基于模糊互补判断矩阵的一致性转化,利用行和归一化方法,得到了模糊互补判断矩阵的一个排序公式,指出目前基于模糊加性一致的排序公式大多都是所提方法的特例,并给出了在增加一个或一组新元素时的保序性条件.     

The Compressibility of Checkerboard Surfaces of Link Diagrams

Consider the checkerboard surfaces defined by some link diagrams. When they are not orientable, one considers the boundary surfaces of small regular neighborhoods of them. This article studies the compressibility problem of these kinds of surfaces in the link complements. The problem is solved by devising a normalization theory for the compressing discs, which brings up an algorithm to read out compressibility directly from the link diagrams. As an application of the algorithm, the compressibility changes under Reidermeister moves are studied. Diagrams from the knot tables are also studied, and surprisingly, some of them are shown to define completely compressible surfaces of this kind. Infinitely many examples of non-alternating knot diagrams with incompressible surfaces of this kind are also constructed.     

一类非齐次树上的非齐次马尔可夫链的若干强极限定理

极限定理一直是国际概率论界研究的中心课题之一.通过构造适当的辅助非负鞅而给出了一类特殊非齐次树上可列状态的非齐次马尔可夫链场的若干强极限定理.