关于域上矩阵广义逆的加法映射

假设F是特征不为2的域,令Mn(F)是F上n×n矩阵的集合.本文证明了f是Mn(F)到自身的矩阵{1}-逆或{1,2}-逆的加法保持算子当且仅当f有:(a)f=0;(b)f(A)=εPAτP-1对任意A∈Mn(F),其中P∈GLn(F),τ-为域F的某个单自同态且x(1)=1,ε=±1;(c)f(A)=εP(Aτ)TP-1对于任意A∈Mn(F),其中τ,ε,P如(b)中一样意义.     

严格α-对角占优M-矩阵A的‖A~(-1)‖_∞的上界估计

针对逆矩阵的无穷范数的上界估计问题,利用严格对角占优M-矩阵逆的无穷范数的上界,给出了严格α-对角占优M-矩阵A的||A~(-1)||_∞的单调递减的上界序列,理论证明及数值分析均表明所得估计改进了某些现有结果.     

||B~(-1)A||的估计及其应用

一、引言 熟知当矩阵B的元素B_(ij)满足 |B_(ii)|-sum from j≠i to |B_(ii)|≥α>0,i=1,2,…,n (1)时,B的逆阵B~(-1)存在,且 ||B~(-1)||≤1/α, (2)此处||·||为最大模,n为矩阵B的阶. 然而,仅有||B~(-1)||的估计往往是不够的,在实际问题中常要估计||B~(-1)A||,此处A为n×n或n×m矩阵.我们用     

严格对角占优M-矩阵A的‖A~(-1)‖_∞的上界估计

针对严格对角占优M-矩阵A的‖A~(-1)‖_∞。的估计问题,利用逆矩阵元素的上界,给出了‖A~(-1)‖_∞的单调递减的上界序列,理论证明及数值算例均表明所得估计改进了某些现有结果.     

三对角矩阵逆的估计

1引言 三对角矩阵出现在很多应用中,例如,在求解常系数微分方程的比值问题,三次样条插值等应用中都会遇到三对角矩阵.因此这类矩阵非常重要,而且也有很多学者致力于这类矩阵的研究.在一些应用中,比如估计条件数和构造稀疏近似逆预条件子,需要计算三对角矩阵的逆,或者估计其逆元素的界.文献[1-7]给出了关于三对角矩阵逆的一些很好的结果,但是,这些结果大都建立在矩阵对角占优的条件之下,这限制了他们的应用.在本文中,我们给出一种一般三对角矩阵逆元素的估计办法.     

S-Nekrasov矩阵的逆矩阵无穷范数的新上界

正1引言H-矩阵逆矩阵无穷范数的估计问题在数值代数、控制论、电力系统理论等众多领域具有广泛的应用.如控制论及神经网络系统的稳定性,线性时滞系统的稳定性,以及分裂矩阵迭代法的收敛性分析等[1-5].1975年J.M.Varah针对H-矩阵的一个重要子类一严格对角占优矩阵(SDD),给出如下估计式(Varah界)[6]:     

AFS结构上矩阵的幂等指数估计

在应用AFS结构(M,τ,X)研究故障诊断问题中,需要寻找正整数r使其满足M2γτ=Mγτ.由于复杂系统对应的AFS结构上矩阵Mτ的阶数较大,为了减少计算量,需要估计出最小的γ.本文给出了基于集合M上的布尔矩阵的概念,并得出其传递闭包的相关性质,在集合M上的布尔矩阵与(0,1)布尔矩阵之间建立一种同态映射并给出其证明,最后运用该映射对r的范围进行了估计.     

四元数矩阵的加正定权的Moore-Penrose型广义逆的显公式

本文利用四元数矩阵的奇异值分解与求解矩阵方程的方法,定出了四元数矩阵A的(1)-逆,(2)-逆,(1,2)-逆及A的加正定权(P,Q)的(3)-逆,(4)-逆,(1,3)-逆,(1,2,3)-逆,(1,4)-逆,(1,2,4)-逆,(1,3,4)-逆,(2,3)-逆,(2,4)-逆的显公式;并得到四元数矩阵的Moore-Penrose型广义逆的全套(共15种)显式。文末就加正定权(P,Q)的(3,4)-道,(2,3,4)-逆显公式的求解问题,提出线性四元数矩阵方程的两个待解问题。     

用二值矩阵表示研究格矩阵的{1}-广义逆和{1,2}-广义逆

用二值矩阵表示的方法(即将格矩阵表示成二值矩阵的线性组合)研究了分配格上矩阵的{1}-广义逆和{1,2}-广义逆. 讨论了{1}-广义逆和{1,2}-广义逆存在的充分必要条件. 给出了判断这些逆是否存在且存在时找出所有这些逆的算法. 从而解决了Kim和Roush(K.H.Kim,F.W.Roush. Generalized fuzzy matrix. Fuzzy Sets and Systems,1980,4(3):293～315)及部分解决了Cao和Kim(Z.Q.Cao,K.H.Kim,F.W.Roush. Incline algebra and applications. New York:John Wiley,1984)提出的问题.     

体上矩阵的广义逆

关于矩阵广义逆的研究,自 R.Penrose 的论文发表以来,目前巳进行得相当深入,域上,以至某些交换环上矩阵的广义逆也已相继进行.但是,由于一般体的非交换性限制,任意体上矩阵的广义逆尚未见过具体的论述。在这篇文章中,我们将对具有一个对合反自同构的体,阐述其上矩阵的广义逆,将域上矩阵的 Moore-Penrose 逆存在的一个充要条件作了相应的推广,并给出了体上矩阵的 Moore-Penrose 逆、(1,…,i)一逆、(2)-逆的显式;最后,我们利用[7]中的一个结果,得到了四元数矩阵的(3)-逆、(4)-逆的显式。     

Estimation of the measure of the image of the ball

Under study is the class of ring Q-homeomorphisms with respect to the p-module. We establish a criterion for a function to belong to the class and solve a problem that stems from M. A. Lavrentiev [1] on the estimation of the measure of the image of the ball under these mappings. We also address the asymptotic behavior of these mappings at a point.     

On the distributions of the ratios of the extreme roots to the trace of the Wishart matrix

In this paper, the authors cosider the derivation of the exact distributions of the ratios of the extreme roots to the trace of the Wishart matrix. Also, exact percentage points of these distributions are given and their applications are discussed.     

On the rational approximation of the sum of the reciprocals of the Fermat numbers

Let $\mathcal{G}(z):=\sum_{n\geqslant0} z^{2^{n}}(1-z^{2^{n}})^{-1}$ denote the generating function of the ruler function, and $\mathcal {F}(z):=\sum_{n\geqslant} z^{2^{n}}(1+z^{2^{n}})^{-1}$ ; note that the special value $\mathcal{F}(1/2)$ is the sum of the reciprocals of the Fermat numbers $F_{n}:=2^{2^{n}}+1$ . The functions $\mathcal{F}(z)$ and $\mathcal{G}(z)$ as well as their special values have been studied by Mahler, Golomb, Schwarz, and Duverney; it is known that the numbers $\mathcal {F}(\alpha)$ and $\mathcal{G}(\alpha)$ are transcendental for all algebraic numbers α which satisfy 0<α<1. For a sequence u, denote the Hankel matrix $H_{n}^{p}(\mathbf {u}):=(u({p+i+j-2}))_{1\leqslant i,j\leqslant n}$ . Let α be a real number. The irrationality exponent μ(α) is defined as the supremum of the set of real numbers μ such that the inequality |α?p/q|<q ^?μ has infinitely many solutions (p,q)∈?×?. In this paper, we first prove that the determinants of $H_{n}^{1}(\mathbf {g})$ and $H_{n}^{1}(\mathbf{f})$ are nonzero for every n?1. We then use this result to prove that for b?2 the irrationality exponents $\mu(\mathcal{F}(1/b))$ and $\mu(\mathcal{G}(1/b))$ are equal to 2; in particular, the irrationality exponent of the sum of the reciprocals of the Fermat numbers is 2.     

Refinement of the asymptotics of the power of the quantile test

One investigates the asymptotic properties of the quantile test, similar to the properties of the Pearson's chi-square test of fit.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 153, pp. 5–15, 1986.The author is grateful to D. M. Chibisov for useful remarks.     

On the approximation of positive operators and the behaviour of the spectra of the approximants

LetT be a positive linear operator on the Banach latticeE and let (S _n ) be a sequence of bounded linear operators onE which converge strongly toT. Our main results are concerned with the question under which additional assumptions onS _n andT the peripheral spectra (S _n ) ofS _n converge to the peripheral spectrum (T) ofT. We are able to treat even the more general case of discretely convergent sequences of operators.