基于下确界函数的稳定性定号导函数理论与设计

通过建立一种基于下确界函数的被称为定号Ｌｉａｐｕｎｏｖ导函数的设计理论与方法，研究了动态系统稳定性的一类新的判定方法。分析了定号导函数的某些性质，与多项式函数的关系，正定性判别，正定性度量，极坐标方法以及υ（ｘ）的正定化算法等基本问题。从而初步形成一个新的、相对系统化的关于稳定性判定的理论框架。

收敛函数列的一个性质

给出函数间断度定义、本性间断点定义及几乎处处连续的本性函数定义,由勒贝格可测函数的本性定理将收敛的几乎处处连续的本性函数列的上、下确界函数本性化,证明收敛的几乎处处连续的本性函数列的无界点集的闭包S∞为零集.

关于凸分析问题的两个注记

指出凸分析问题的两个定理(凹规划定理和对偶定理)的证明中所存在的漏洞,并给出正确的证明.首先,将凸集的端子集的概念推广到一般集合的端集,再利用推广后的端集正确地证明了凹规划定理.其次,给出局部凸空间的一个引理,并利用这个引理证明了共轭函数的对偶定理.

Algorithms for computing the global infimum and minimum of a polynomial function

By catching the so-called strictly critical points,this paper presents an effective algorithm for computing the global infimum of a polynomial function.For a multivariate real polynomial f ,the algorithm in this paper is able to decide whether or not the global infimum of f is finite.In the case of f having a finite infimum,the global infimum of f can be accurately coded in the Interval Representation.Another usage of our algorithm to decide whether or not the infimum of f is attained when the global infimum of f is finite.In the design of our algorithm,Wu’s well-known method plays an important role.

A CLOSEDNESS CRITERION FOR THEDIFFERENCE OF TWO CLOSED CONVEXSETS IN GENERAL BANACH SPACES

The authors give some sufficient conditions for the difference of two closed convex sets to be closed in general Banach spaces, not necessarily reflexive.