Additive Maps Preserving Nilpotent Operators or Spectral Radius

Let X be a （real or complex） Banach space with dimension greater than 2 and let B0（X） be the subspace of B（X） spanned by all nilpotent operators on X. We get a complete classification of surjective additive maps Ф on B0（X） which preserve nilpotent operators in both directions. In particular, if X is infinite-dimensional, we prove that Ф has the form either Ф（T） = cATA^-1 or Ф（T） = cAT＇A^-1, where A is an invertible bounded linear or conjugate linear operator, c is a scalar, T＇ denotes the adjoint of T. As an application of these results, we show that every additive surjective map on B（X） preserving spectral radius has a similar form to the above with ｜c｜ = 1.     

NECESSARY CONDITIONS FOR OPTIMAL CONTROLS OF SEMILINEAR ELLIPTIC VARIATIONAL INEQUALITIES INVOLVING STATE CONSTRAINT

This paper deals with maximum principle for some optimal control problem governed by some elliptic variational inequalities. Some state constraints are discussed. The basic techniques used here are based on those in [1] and a new penalty functional defined in this paper.     

Boundedness of Multilinear Operators on Herz Type Spaces： Extreme Cases

In this paper, two classes of closely related multilinear singular and fractional integrals,which include the commutators as special cases, are studied and their boundedness on Herz type spaces is discussed. In fact, it is proved that these operators are actually not bounded in certain extreme cases.     

Local Prediction of Chaotic Time Series Based on Support Vector Machine

Based on phase space delay-coordinate reconstruction of a chaotic dynamics system, we propose a local prediction of chaotic time series using a support vector machine （SVM） to overcome the shortcomings of traditional local prediction methods. The simulation results show that the performance of this proposed predictor for making onestep and multi-step prediction is superior to that of the traditional local linear prediction method and global SVM method. In addition, it is significant that its prediction performance is insensitive to the selection of embedding dimension and the number of nearest neighbours, so the satisfying results can be achieved even if we do not know the optimal embedding dimension and how to select the number of nearest neighbours.     

因素空间理论与知识表示的数学框架(XⅢ)──描述架中概念的结构(2)

本文是［１，１２］的继续，研究描述架中概念的结构；本文讨论后半部分，内容涉及概念内涵与外延的转换，清晰关系的内投影与内变换，概念的结构＊以及有关问题的注记。     

A Fixed Point Theorem for Multi—valued Composite Increasing Operators

Ａ　Ｆｉｘｅｄ　Ｐｏｉｎｔ　Ｔｈｅｏｒｅｍ　ｆｏｒ　Ｍｕｌｔｉ－ｖａｌｕｅｄ　Ｃｏｍｐｏｓｉｔｅ　Ｉｎｃｒｅａｓｉｎｇ　ＯｐｅｒａｔｏｒｓＬｉＦｅｎｇｙｏｕ（李凤友）（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ，Ｔｉａｎｊｉｎ＇ＮｏｒｍａｌＵｎｉ...     

一个强极限定理

设是可列非齐次马氏链，本文通过利用［１］中提出的在Ｗｉｅｎｅｒ概率空间的一种实现，而给出了一个对任意可列非齐次马氏链普遍成立的强极限定理。     

非空交定理及其应用

本文得到了广义区间空间中几个参数型非空交定理，并用此结果证明了一些新型极大极小定理，截口定理，重合定理，以及变分不等式解的存在性定理。本文中的结果包含（１，３，５－１２，１４－１６）中相应结果。     

映象方程多解问题的某些研究

本文用ｆｐ－同伦方法，在一定的技巧和变换的配合下，在紧性条件支持下，研究了赋范线性空间中一类集值映象方程的多解问题。还给出所得理论结果的一个应用。     

李群,拓扑与微分几何

该文介绍严志达院士的若干工作，以庆贺他的八十寿辰．