THE POSITIVITY OF THE CHERN CHARACTERS OF A HYPERSURFACE WITH SINGULARITIES

The Chern characters of a hypersurface with singularities are appropriatecombinations of Ehresmann characters of this hypersurface.The Chern characters are usualChern numbers when the hypersurface is smooth.Some sorts of inequalities for these Cherncharacters of an n-dimensional hypersurface are derived.     

THE POLE ASSIGNMENT OF LINEAR SYSTEMS

In this paper the pole assignment problem of a time invariant linear control system issolved by using the Wu Elimination Method.In general,the questions are classified into(i)the poleassignment by using state feedback,(ii)the pole assignment by using output feedback,(iii)the poleassignment via dynamic compensator.The key point of all these problems is to solve a certaincorresponding system of polynomial equations.Based on algebraic geometry,the Wu methodprovides a mechanical algorithm for solving the system of polynomial equations.Therefore,a unifieddefinite algorithm for solving all these problems is given in this paper.During the procedure ofelimination,the unknowns are automatically separated into parameters and apparent variables.Thus,the freedom of the corresponding feedback can be defined as the number of parameters.Meanwhile,the explicit expressions of the apparent variables depending on the parameters areobtained.     

几何代数和几何计算(一)

数学是研究现实世界的“数”与“形”的科学。数学就是围绕这两个概念的演变而发展的，也通过这两个基本概念应用到各个不同的领域中去。代数是研究“数”的学科，几何是研究“形”的学科。数学科学发展的历程中两者彼此独立，又相互缠绕。几何（形）的概念用代数（数）表示，几何的目标可经过代数计算实现；反之，代数语言赋有了几何背景，可更加直观地理解它们的意义。发现它们的丰富内涵。吴文俊院士指出：几何代数化，在近代数学的兴起和发展过程中发挥着决定性的作用。     

THE EQUALITIES OF THE CHERN CLASSES

In this paper we generalize the results of [1]and prove that,for any given 4≤k≤n,theChern classes of hypersurface V_n corresponding to the partitions of k also satisfy some equalities.Furthermore,we obtain the equalities of Chern classes concretely for k=4,5,6.     

Q-ANALOG OF LI SHAN-LAN IDENTITY

The expansions of the higher power of Gaussian polynomial are studied in this paper.And an elementary proof of the Q-analog Li Shan-lan identity is provided.     

THE DIMENSIONS OF IRREDUCIBLE REPRESENTATIONS OF THE SYMMETRIC GROUP

In this note we derive the demension formula of the irreducible representations ofsymmetric groups from its defination by using the character formula of the symmetric groupobtained in[7].Thus we provid a directly proof of the hook formula from the point of view ofthe character of symmetric groups.     

SU(3)规范场的数学表述(闵空间)

本文研究4维闵科夫斯基空间SU(3)规范场的正规化问题.在对Yang-Mills方程的推导进行了分析的基础上,导出了恰当的Yang-Mills方程,它具有明确的几何意义.然后,应用数学机械化方法构造了一类线性微分变换,称之为SU(3)场的示性变换.经由示性变换,将非线性的恰当的Yang-Mills方程变为一组线性方程,实现了SU(3)规范场的场方程的线性化,即场方程的正规化.从而证明了SU(3)规范场包括8个独立的规范场.     

几何代数和几何计算(二)

时代的需求 数学科学的发展要适应时代的需求。 欧洲的文艺复兴，极大地促进了自然科学的进步．各类新的重大发现，如天文学、力学、机械学等，只有成功应用了数学，才能形成完美的科学定律。坐标几何正是适应这样的时代需求应运而生的，它的建立改变了科学的历史进程。     

数学机械化与自动推理平台

数学机械化就是将数学研究的主要活动--"推理与计算"实现机械化或自动化的过程.本项目研究数学机械化基础理论、信息技术若干关键问题的应用、自动推理平台开发.在微分方程求解、不等式自动证明、全局优化、组合恒定式自动证明、Clifford代数计算、几何自动作图与智能CAD、信息压缩、图像伪装、基于Stewart平台的数控技术、CAGD等方面取得一批重要成果.在软件方面,开发出有自主版权的智能软件.在图像压缩方面,提出的"多成分变换"技术为JPEG2000图像压缩国际标准所采纳.