我国各地区人口素质差异的主成分和聚类分析

本文利用国家统计局人口变动情况抽样调查数据，运用主要成分和聚类分析方法，揭示了１９９７年我国３０个省份（不包括西藏）的人口素质差异。首先通过人口素质指标体系确立人口素质的综合指标，在此基础上来评价各地的人口素质状况，并按其素质的高低将全国３０个省份的人口素质状况分为四大类，同时，对各省人口素质存在差异的原因进行了归纳和总结  

Volterra级数在非线性网络分析及故障诊断中的应用

本用Volterra级数求解描述非线性网络性状的非线性微分方程，得出了网络响应的Volterra递推算法和分析步骤及其在故障诊断中的应用。  

An Analytic Center Cutting Plane Method for Solving Semi-Infinite Variational Inequality Problems

We study a variational inequality problem VI(X,F) with X being defined by infinitely many inequality constraints and F being a pseudomonotone function. It is shown that such problem can be reduced to a problem of finding a feasible point in a convex set defined by infinitely many constraints. An analytic center based cutting plane algorithm is proposed for solving the reduced problem. Under proper assumptions, the proposed algorithm finds an -optimal solution in O*(n ²/²) iterations, where O*(·) represents the leading order, n is the dimension of X, is a user-specified tolerance, and is the radius of a ball contained in the -solution set of VI(X,F).  

风力机叶尖涡尾迹结构PIV测量研究

空气动力研究与发展中心低速空气动力研究所依托工程型大风洞(实验段直径3.2 m),采用高分辨率CCD相机(4 008像素×2 672像素),针对旋转状态下的风力机叶片尾流开展大视场(单个观测区域达到570 mm×380 mm)PIV(particle image velocimetry)测量,以NREL UAE PhaseⅥ风力机叶片1/8缩比模型为实验对象,获取了叶尖涡产生、发展的流动数据,为研究风力机叶尖涡结构和流动机理研究提供重要的基础数据.观测结果表明,叶尖涡从后缘脱落后首先有一个短时间的向内运动,然后随着尾流的膨胀向外运动,其涡强度则先是短时间内降低,然后随着涡的卷起而增强,从而形成一个强大的叶尖涡.在实验观察范围内叶尖涡在来流方向的迁移规律近似线性.  

双目标DEA模型及其在商业银行评价中的应用

为了解决传统DEA模型所存在的判别能力弱和不现实权重两个缺陷,本文提出了一种双目标DEA模型。该模型在相同的约束条件下,同时以最大化各自效率和最小化所有效率值差异为目标。最后,通过某商业银行分支机构效率评价实例对所提出的方法进行了演示,说明了所提出方法的优点,着重说明了该方法可以很好地解决传统DEA方法所存在的两个缺陷。  

OD-characterization of Almost Simple Groups Related to U3（5）

Let G be a finite group with order ｜G｜=p1^α1p2^α2……pk^αk, where p1 〈 p2 〈……〈 Pk are prime numbers. One of the well-known simple graphs associated with G is the prime graph （or Gruenberg- Kegel graph） denoted .by г（G） （or GK（G））. This graph is constructed as follows： The vertex set of it is π（G） = {p1,p2,…,pk} and two vertices pi, pj with i≠j are adjacent by an edge （and we write pi - pj） if and only if G contains an element of order pipj. The degree deg（pi） of a vertex pj ∈π（G） is the number of edges incident on pi. We define D（G） ：= （deg（p1）, deg（p2）,..., deg（pk））, which is called the degree pattern of G. A group G is called k-fold OD-characterizable if there exist exactly k non- isomorphic groups H such that ｜H｜ = ｜G｜ and D（H） = D（G）. Moreover, a 1-fold OD-characterizable group is simply called OD-characterizable. Let L ：= U3（5） be the projective special unitary group. In this paper, we classify groups with the same order and degree pattern as an almost simple group related to L. In fact, we obtain that L and L.2 are OD-characterizable; L.3 is 3-fold OD-characterizable; L.S3 is 6-fold OD-characterizable.  

Delta算子Riccati方程研究的新结果

基于Delta算子描述，统一研究连续时间代数Riccati方程(CARE)和离散时间代数Riccati方程(DARE)的定界估计问题，提出了统一代数Riccati方程(UARE)解矩阵的上下界，给出UARE中P与R和Q的几个基本关系．  

变系数Euler-Bernoulli梁振动发展系统的存在性

讨论变系数Euler-Bernoulli梁振动系统{uu(x,t) η(t)uxxxx(x,t)=0,0＜x＜1,0≤t≤T u(0,t)=ux(0,t)=0,0≤t≤t -uxxx(1,t) muu(1,t)=-αu1(1,t) βuxxx(1,t),0≤t≤T uxt(1,t) =-γuxx(1,t),0≤t≤t u(x,0)=u1(x),u1(x,0),0≤x≤1证明了该系统产生一个发展系统．  

A Braided Simplicial Group

By studying the braid group action on Milnor's constructionof the 1-sphere, we show that the general higher homotopy groupof the 3-sphere is the fixed set of the pure braid group actionon certain combinatorially described groups. This establishesa relation between the braid groups and the homotopy groupsof the sphere. 2000 Mathematical Subject Classification: 20F36, 55P35, 55Q05,55Q40, 55U10.  

关于有限群不可约特征标零点的一点注记

在这篇文章中,我们分类了每一个非线性不可约特征标的零点集最多由$3$个共轭类组成的有限亚交换群的结构.