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1.
多元统计中期望向量的线性容许估计   总被引:9,自引:0,他引:9  
设Y1,Y2,…,Yn独立同分布,EY1=β,CovY1=Σ,这里β∈Rm与Σ:m×m>0均未知.取L1(d,β)=(d-β)′(d-β),L2=(d,β)(d-β)′,L={L1Y1+L2Y2+…+LnYn:Li为m阶实方阵,i=1,2,…,n}.本文在L1和L2下分别给出了线性估计在L中是β的容许估计的充要条件.  相似文献   

2.
矩阵损失下均值向量的线性可容许估计   总被引:3,自引:0,他引:3  
设Y=(Y1,…,Yn)′相互独立,EY=Xβ,CovY=Xdiag(β1,…,βn)X′,β=(β1,…,βn)′∈R+n为参数,R+=(0,+∞),X为已知的元素非负且对角线元素为正的n阶满秩矩阵,估计均值Xβ,选取损失函数为矩阵损失,估计类为D={AY:A为元素非负的n阶矩阵}.本文研究AY在D中的容许性,获得了AY在D中是Xβ的容许估计的充要条件.  相似文献   

3.
本文研究n阶时滞差分方程的边值问题:x(k+n)=f(k,xk(),x(k),x(k+1),…,x(k+n-1)),k∈IT,x(m)=φ(m),m∈I-r,x(1)=a1,x(2)=a2,…,x(n-2)=an-2,x(T)=A,{得到了解的存在性和唯一性的结果.  相似文献   

4.
1.引言 CG法对于变量个数很多的问题,是很有用的.1970年后它有了许多改进和发展,CCG法以正定圆锥函数为基础[1],它的一般方法是:设圆锥函数为 2]其中: V= V(x)=1+ aTx ≠ 0;, r ∈R1为常量; a,g ∈ Rn为常向量;x ∈ Rn为变向量;A∈Rn×n为对称正定矩阵.算法[1]:预先给出初始近似点x0∈ Rn及初始搜索方向 p0;满足:其中“I”是单位矩阵, V0= V(x0)= 1+ atx0及记号“”是函数的梯度.迭代格式为: xk+1= xk +λkpk,k= 0,1,2,…(3…  相似文献   

5.
Hadamard积和酉不变范数不等式   总被引:9,自引:0,他引:9  
詹兴致 《数学进展》1998,27(5):416-422
设Mn,m是n×m复矩阵空间,Mn≡Mn,n.对于Hermite阵G,H∈Mn,GH表示G-H半正定.记A和B的Hadamard积为AB.本文证明了若A,B∈Mn正定,而X,Y∈Mn,m任意,则(XA-1X)(YB-1Y)(XY)(AB)-1(XY),XA-1X+YB-1Y(X+Y)(A+B)-1(X+Y).这推广和统一了一些现存的结果.设‖·‖为任意酉不变范数,I是单位矩阵.本文还证明了对于X∈Mn,m和A∈Mn,B∈Mm,若AI,BI,则函数f(p)=‖ApX+XBp‖在[0,∞)上单调递增.  相似文献   

6.
本文讨论了如下一类线性errors-in-variables模型——多元线性结构关系模型β′xk+α=0,ξk=xk+εk.{k=1,2,…,n.其中,{xk:k=1,2,…,n}为一组i.i.d.的m维随机向量,{εk:k=1,2,…,n}是i.i.d.的随机误差,E(ε1)=0,Var(ε1)=σ2Im.且{xk:k=1,2,…,n}与{εk:k=1,2,…,n}相互独立.在一些条件下,我们证明了估计量β,α,σ2的强相合性、唯一性,并给出了估计量的收敛速度为o(n-1-1q),这里q∈[1,2).对于E(x1)u1和Var(x1)Vx的估计也得出了同样的结果  相似文献   

7.
乐茂华 《数学学报》1996,39(6):728-732
设m是正整数,f(X,Y)=a0Xn+a1X(n-1)Y+...+anYn∈Z[X,Y]是Q上不可约化的叫n(n≥3)次齐次多项式。本文证明了:当gcd(m,a0)=1,n≥400且m≥10(35)时,方程|f(x,y)|=m,x,y∈z,gcd(x,y)=1,至多有6nv(m)组解(x,y),其中v(m)是同余式F(z)=f(z,1)≡0(modm)的解数。特别是当gcd(m,DF)=1时,该方程至多有6n(ω(m)+1)组解(x,y),其中DF是多项式F的判别式,ω(m)是m的不同素因数的个数.  相似文献   

8.
E=E(m,n,k)={(z,ω)∈C^n+m:│z│^2+│ω│^2k〈1,z∈C^n,ω∈C^m,k〉0}是C^m+m中的一类有界拟凸域。该文证明了在δE的强拟凸点上,当m〉1时,lim(z,ω)→δEJE((z,ω))=π^n+m(n+m+1)^n/(n+m)!.m=1时,lin(z,ω)→δEJE(z,ω))=π^n+1(n=)^n+1/(n+1)!,在δE的弱拟凸点上,上述极限不存在。  相似文献   

9.
一个应用广泛的不等式湖南沅陵六中周永国定理若a、b∈R+,n∈N,则当且仅当a=b时等号成立.证对任意的非负整数k≤n,有(k=0,1,…,n),上面n+1式相加,得等号当且仅当a=b时成立.定理有着广泛的应用,下面举例说明.例1设a、b、c是△AB...  相似文献   

10.
数学问题解答1996年12月号问题解答(解答由问题提供人给出)1046求所有这样的△ABC,它的三个边长a,b,c与面积S的数值恰好组成一组从小到大排列的连续自然数.解不妨设a=n-1,b=n,c=n+1,s=n+2,这里n>1,n∈N.将a,b,c...  相似文献   

11.
<正>Submission Authors must use LaTeX for typewriting,and visit our website www.actamath.com to submit your paper.Our address is Editorial Office of Acta Mathematica Sinica,Academy of Mathematics and Systems Science,Chinese Academy of Sciences,Beijing 100190,P.R.China.  相似文献   

12.
13.
正August 10-14,2015Beijin,China The International Congress on Industrial and Applied Mathematics(ICIAM)is the premier international congress in the field of applied mathematics held every four years under the auspices of the International Council for Industrial and Applied Mathematics.From August 10 to 14,2015,mathematicians,scientists  相似文献   

14.
The present paper investigates the fractal structure of fractional integrals of Weierstrass functions. The ezact box dimension for such functions many important cases is established. We need to point out that, although the result itself achieved in the present paper is interesting, the new technique and method should be emphasized. These novel ideas might be useful to establish the box dimension or Hausdorff dimension (especially for the lower bounds) for more general groups of functions.  相似文献   

15.
English Series     
正1 Aims and Scope Acta Mathematicae Applicatae Sinica(English Series)is a quarterly journal established by the Chinese Mathematical Society.The journal publishes high quality research papers from all branches of applied mathematics,particularly welcomes those from partial differential equations,computational mathematics,applied probability,mathematical finance,statistics,dynamical systems,optimization and management science.  相似文献   

16.
17.
We characterize congruence lattices of standard QBCC-algebras and their connection with the congruence lattices of congruence kernels. Work on the paper was supported by Council of Czech Government No J14/98:153100011.  相似文献   

18.
A new class of sets in ideal topological spaces is introduced and using these sets, a decomposition of continuity is given.   相似文献   

19.
We obtain (a) necessary and sufficient conditions and (b) sufficient conditions for a compact (countably compact) set to be closed in products (sequential products) and subspaces (sequential subspaces) of normal spaces. As a consequence of these, sufficient conditions are obtained for (i) the closedness of arbitrary (countable) union of closed sets and (ii) the equality of the union of the closures and the closure of the union of arbitrary (countable) families of sets in these spaces. It is also shown that these results do not hold for quotients of even T 4,-spaces.  相似文献   

20.
The current paper considers the problem of recovering a function using a limited number of its Fourier coefficients. Specifically, a method based on Bernoulli-like polynomials suggested and developed by Krylov, Lanczos, Gottlieb and Eckhoff is examined. Asymptotic behavior of approximate calculation of the so-called "jumps" is studied and asymptotic L2 constants of the rate of convergence of the method are computed.  相似文献   

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