半群CSPO_n中星理想的秩和相关秩

设自然数n≥4,CSPO_n是有限链[n]上的严格部分保序且压缩奇异变换半群.对任意的r(0≤r≤n-1),记N_P~*(n,r)={α∈CSPO_n:|Im(α)|≤r}为半群CSPO_n的双边星理想.通过对秩为r的元素和星格林关系的分析,分别获得了半群N_P~*(n,r)的极小生成集和秩.进一步确定了当0≤l≤r时,半群N_P~*(n,r)关于其星理想N_P~*(n,l)的相关秩.     

压缩变换半群CT_n中一类元素的基数

压缩变换半群CT_n是全变换半群T_n中的压缩元组成的子半群.主要讨论了当n≥5时CT_n中一类元素{α∈CT_n|1α=1,((n-2)α,(n-1)α,nα)=(3,2,1))的基数并得到了递推公式:LN_n~((1,321))=d-d_1LN_(n-1)~(((1,321))-…-d_(k-3)LN_(n-(k-3))~((1,321)).     

半群PO_(n,r)的秩

设POn为Xn上的保序部分变换半群.对任意的2≤r≤n一1,考虑半群PO_(n,r)={α∈PO_n:Im(α)■[r]}([r]={1,2,…,r}),证明了PO_(n,r)的秩为Σn-1k=r(nk)((k-1)(r-1))+r-1.     

OI_n的理想K(n,r)的极大逆子半群

Xn为n元有限集,OIn为Xn上的一切保序严格部分一一变换半群.记K(n,r)={α∈OIn∶|Tmα|≤r}(0≤r≤n-1)则K(n,r)(0≤r≤n-1)是OIn的理想.我们刻划了K(n,r)(1≤r≤n-1)的极大逆子半群.     

几个组合恒等式的概率证法

关于组合恒等式,在中学教学中一般是采用二项式的工具证明的。现在的中学教材,在排列组合、二项式紧后的内容是概率,如用概率的想法来证明组合恒等式将是有意思的,而且一般还比较简单。如在教学中给学生以介绍则是很有益的。本文介绍常用的五个重要组合恒等式的概率法。 1.C_n~r=C_(n-1)~r+C_(n-1)~(r-1)(1≤r≤n) 证:从装有大小相同的一个红球余为白球的n个球的口袋中任意摸出r个球,设摸到红球的事件为A,则有: P(A)=C_(n-1)~(r-1)+C_n~r;P(?)=C_(n-1)~r+C_n~r.     

一族特殊的单叶函数

<正> 设S_λ~*(α,β)表示函数类在单位圆u{z;|z|<1}内解析映象,且对0<λ≤1;0≤α≤(1+λ)/2;0<β≤1;满足设C_λ~*(α,β)表示函数类在U 内解析,且zf~′(z)属于S_λ~*(α,β)。当λ=1时,为函数类S_1~*(α,β)和C_1~*(α,β).文中给出了这两类函数的一些结果,本文就     

单位上三角矩阵群的注记

记Tr_1(n,Z)是整数环Z上对角线元素全是1的全体上三角矩阵组成的群,k_(ij)(1≤i相似文献   

齐次Fourier-Besov-Morrrey空间上广义磁流体力学方程组的存在性和渐近稳定性

考虑了R~n上n维广义磁流体力学方程组,当初值("_0,d_0)∈FN_(r,λ,∞)~(-β)×FN_(r,λ,∞)~(-β)时,广义磁流体力学方程组对应的Cauchy问题的存在性和渐近稳定性,其中1≤r≤∞,0≤λ≤n或者1≤r≤∞,λ=0以及n≥3,1/2≤σ=α≤(n+2)/4-(n-λ)/(4r),β=2σ-1+(n-λ)/r-n.最后,得到了广义磁流体力学方程组一类自相似解的渐近稳定性.     

一类非线性广义样条最佳L_p逼近的光滑性

设L是常系数n阶线性微分算子,m∈N, 0=s_00适当小,v=1,…,r}本文证明了设f∈L_p[0,1],1≤p<∞,那末当n≥2时,存在f的最佳L_p[0,1]逼近样条(?)∈C[0,1]∩φ~*(m,q)。当n≥3时,存在f的最佳L_p[0,1]逼近样条(?)∈C~1[0,1]∩φ~*(m,q)。     

半群OCK_n的理想的极大子半群

设X_n={1,2,…,n}并赋予自然数序,OCK_n是X_n上的具有核连续的保序变换半群.将考虑OCK_n的理想OCK(n,r)={α∈OCK_n:|imα|≤r}(3≤r≤n-1),并得到了OCK(n,r)的极大子半群的完全分类.     

Rank Properties in Finite Semigroups II: The Small Rank and the Large Rank

This paper is concerned with the application of two possible definitions of rank to certain well-known semigroups.AMS Subject Classification (2000), 20M10     

用受评者的等级或名次给评委们评名次

由评委们评定受评者的等级或名次,是一种普遍方式,但其中各个评委的作用识别问题却被忽视,因而无法确切地评价所选择的评委是否都很称职.本文提出根据受评者的等级或名次总体结果,建立识别各评委作用的反馈控制,以提高评选活动的质量.因此构造了识别各评委作用的二次规划数学模型,能够在普遍情形下得出唯一的求解结果.并且针对模型的特殊数据结构,给出了用约束最小二乘法求解的显式简便计算式,可以方便求解.进而使用这一方法,作了具体实例分析.     

含有多个圈的图的秩

研究了含有多个圈的图的邻接矩阵的秩.将k(k≥2)条点不交的路,首和尾分别粘合得到的图称为Θ-图.用Γ(k-1)表示含有Θ-图作为导出子图的(k-1)-圈图的集合,而用C(η,k)表示含有n个顶点和k个边不交的圈的图的集合.确定了Γ(k-1)中秩等于5和6的图以及C(n,k)中秩等于4,5和6的图.     

A New Approximation of the Matrix Rank Function and Its Application to Matrix Rank Minimization

The matrix rank minimization problem is widely applied in many fields such as control, signal processing and system identification. However, the problem is NP-hard in general and is computationally hard to directly solve in practice. In this paper, we provide a new approximation function of the matrix rank function, and the corresponding approximation problems can be used to approximate the matrix rank minimization problem within any level of accuracy. Furthermore, the successive projected gradient method, which is designed based on the monotonicity and the Fréchet derivative of these new approximation function, can be used to solve the matrix rank minimization this problem by using the projected gradient method to find the stationary points of a series of approximation problems. Finally, the convergence analysis and the preliminary numerical results are given.     

P-Geometries of Rank 3

Under minor extra assumptions, we classify P-geometries of rank 3. Previously, a classification was known only for flag-transitive P-geometries.     

On the Rank of a Binary Form

We describe in the space of binary forms of degree d the strata of forms having a given rank. We also give a simple algorithm for determining the rank of a given form.     

A Remark on the Rank Conjecture

We prove a result about the action of -operations on the homology of linear groups. We use this to give a sharper formulation of the rank conjecture as well as some shorter proofs of various known results. We formulate a conjecture about how the sharper formulation of the rank conjecture together with another conjecture could give rise to a different point of view on the isomorphism between and K_n^{(p)} (F)$ for an infinite field F, and we prove part of this new conjecture.     

Sets Computing the Symmetric Tensor Rank

Let ${\nu_{d} : \mathbb{P}^{r} \rightarrow \mathbb{P}^{N}, N := \left( \begin{array}{ll} r + d \\ \,\,\,\,\,\, r \end{array} \right)- 1,}$ denote the degree d Veronese embedding of ${\mathbb{P}^{r}}$ . For any ${P\, \in \, \mathbb{P}^{N}}$ , the symmetric tensor rank sr(P) is the minimal cardinality of a set ${\mathcal{S} \subset \nu_{d}(\mathbb{P}^{r})}$ spanning P. Let ${\mathcal{S}(P)}$ be the set of all ${A \subset \mathbb{P}^{r}}$ such that ${\nu_{d}(A)}$ computes sr(P). Here we classify all ${P \,\in\, \mathbb{P}^{n}}$ such that sr(P) <  3d/2 and sr(P) is computed by at least two subsets of ${\nu_{d}(\mathbb{P}^{r})}$ . For such tensors ${P\, \in\, \mathbb{P}^{N}}$ , we prove that ${\mathcal{S}(P)}$ has no isolated points.     

半群SOP_n的平方幂等元秩

设SOP_n是M上的奇异方向保序交换半群.证明了半群SOP_n是由秩为n-1的平方幂等元生成的,且它的平方幂等元秩为n.