首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 973 毫秒
1.
蒋美跃  裴明亮 《数学进展》1994,23(2):97-114
本文介绍Aubry-Mather理论近年来的发展情况。文章讨论了该理论与KAM理论、保面积映射不动点理论的联系,简单地介绍了它的一些推广。作为该理论的应用,对平面Hamil-ton系统Mather集的存在性给出了一些结果。  相似文献   

2.
在「1」中,C^∞映射芽在Mather定义的群A^「2」中的一个子群下的万有开折得到了讨论,本文则刻画了开折的无穷小稳定性。  相似文献   

3.
本文在文[4]的基础上讨论了双重时序AR(1)-MA(q)模型的相关结构,在不假定白噪声序列为正态的情况下,证明了安鸿志[2]关于模型的相关结构的猜想是正确的,具体地构造了AR(1)-MA(3)模型的相关结构,并与ARMA模型进行了初步的比较,给出了一些抛砖引玉的讨论.  相似文献   

4.
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   

5.
设A是奇异M-矩阵,A=M-N是A的图相容弱正则分裂.本文研究迭代矩阵M-1N的谱性质,得到与迭代矩阵的指数有关的一个定理:ind0(A)=ind1(M-1N).它推广了H.Schneider和作者的结果.  相似文献   

6.
设A是奇异M-矩阵,A=M-N是A的图相容弱正则分裂。本文研究迭代矩阵M^-1N的谱性质,得到与迭代矩阵的指数有关的一个定理:ind0(A)=ind1(M^-1N).它推广了H.Schneider和作者的结果。  相似文献   

7.
本文利用伪单调算子理论研究如下变分不等式问题:求x∈M,使得〈Ax,y-x〉+〈Gx,y-x〉≥〈f,y-x〉,?y∈M.并将所得结果应用于拟线性椭圆型边值问题的求解.  相似文献   

8.
一个与G-分次环和G-集的Smash积有关的Maschke-Type定理   总被引:1,自引:0,他引:1  
对任意群G,[1]研究了有单位元1的G-分次环与有限可迁G-集的Smash积.在本文中,我们对任意可迁G-集A讨论了具有局部单位元的G-分次环与G-集A的Smash积,证明了有关的一个Maschke-tyPe定理.推广了[2][3]中的一些重要结果.  相似文献   

9.
一个MATCH(n,k,λ)-设计就是完全图Kn的一个k-匹配集合,使得Kn的每一对狡立边恰好出现在λ个k-匹配中,本文构造了一个MATCH(14,3,1)-设计,解决了文献(1)中一个尚未解决的问题,同时还得到了个MATCH(42,3,1)-设计。  相似文献   

10.
孙建华 《数学杂志》1996,16(2):233-238
对任意群G,〔1〕研究了有单位元1的G-分次环与有限可迁G-集的Smash积,在本文中,我们对任意可迁G-集A讨论了具有局部单元元的G-分次环与G-集A的Smash积,证明了有关的一个Mahchke-type定理,推广了〔2〕〔3〕中的一些重要结果。  相似文献   

11.
12.
张丽娜  吴建华 《数学进展》2008,37(1):115-117
One of the most fundamental problems in theoretical biology is to explain the mechanisms by which patterns and forms are created in the'living world. In his seminal paper "The Chemical Basis of Morphogenesis", Turing showed that a system of coupled reaction-diffusion equations can be used to describe patterns and forms in biological systems. However, the first experimental evidence to the Turing patterns was observed by De Kepper and her associates(1990) on the CIMA reaction in an open unstirred reactor, almost 40 years after Turing's prediction. Lengyel and Epstein characterized this famous experiment using a system of reaction-diffusion equations. The Lengyel-Epstein model is in the form as follows  相似文献   

13.
In this paper, we study the explicit representation and convergence of (0, 1; 0)-interpolation on infinite interval, which means to determine a polynomial of degree ≤ 3n - 2 when the function values are prescribed at two set of points namely the zeros of Hn(x) and H′n(x) and the first derivatives at the zeros of H′n(x).  相似文献   

14.
As early as in 1990, Professor Sun Yongsheng, suggested his students at Beijing Normal University to consider research problems on the unit sphere. Under his guidance and encouragement his students started the research on spherical harmonic analysis and approximation. In this paper, we incompletely introduce the main achievements in this area obtained by our group and relative researchers during recent 5 years (2001-2005). The main topics are: convergence of Cesaro summability, a.e. and strong summability of Fourier-Laplace series; smoothness and K-functionals; Kolmogorov and linear widths.  相似文献   

15.
Schr(o)dinger operator is a central subject in the mathematical study of quantum mechanics.Consider the Schrodinger operator H = -△ V on R, where △ = d2/dx2 and the potential function V is real valued. In Fourier analysis, it is well-known that a square integrable function admits an expansion with exponentials as eigenfunctions of -△. A natural conjecture is that an L2 function admits a similar expansion in terms of "eigenfunctions" of H, a perturbation of the Laplacian (see [7], Ch. Ⅺ and the notes), under certain condition on V.  相似文献   

16.
正Guest Editors:Hong Chen,Shanghai Jiao Tong University,Shanghai,China Guohua Wan,Shanghai Jiao Tong University,Shanghai,China David Yao,Columbia University,New York,USA Scope:Healthcare delivery worldwide has been fraught with high cost,low efficiency and poor quality of patient care service.For the field of operations research(OR),healthcare offers some of the biggest challenges as well as best opportunities in  相似文献   

17.
18.
Due to the resolution of current laser technology, the accuracy of corneal topography as measured by the videokeratoscope is no longer adequate to provide precise enough data for refractive surgery or for the fitting of customized contact lenses. We present an algorithm for recovering corneal topography that makes use of modern differential geometric techniques and numerical descent in Sobolev spaces. We believe this algorithm may be used with the photo- and videokeratoscope to increase the accuracy of the recovered corneal topography.  相似文献   

19.
Let {Ln(A,λ)(x)}n≥0 be the sequence of monic Laguerre matrix polynomials defined on [0, ∞) by Ln(A,λ)(x)=n!/(-λ)n∑nk=0(-λ)κ/k!(n-1)! (A I)n[(A I)k]-1 xk,where A ∈ Cr×r. It is known that {Ln(A,λ)(x)}n≥0 is orthogonal with respect to a matrix moment functional when A satisfies the spectral condition that Re(z) > - 1 for every z ∈σ(A).In this note we show that forA such that σ(A) does not contain negative integers, the Laguerre matrix polynomials Ln(A,λ) (x) are orthogonal with respect to a non-diagonal SobolevLaguerre matrix moment functional, which extends two cases: the above matrix case and the known scalar case.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号