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231.
We give a closed formula for topological K-theory of the homogeneous space N/, where is the standard integer lattice in the simply connected Heisenberg Lie group N of dimension 2n+1, n
. The main tools in our calculations are obtained by computing diagonal forms for certain incidence matrices that arise naturally in combinatorics. 相似文献
232.
广义对角占优阵的一个等价条件 总被引:2,自引:0,他引:2
郑秉文 《纯粹数学与应用数学》1999,15(2):37-41
给出了实方阵为广义对角占优阵的充要条件,同时给出了判断广义对角占优阵可靠,可行,较简单方法。 相似文献
233.
TZEKIS P.; KARAMPETAKIS N. P.; VARDULAKIS A. I. 《IMA Journal of Mathematical Control and Information》1999,16(4):391-401
The main purpose of this paper is to determine two new algorithmsfor the division of the polynomial matrix B(s) R[s]pxq by A(s) R[s]pxp (a) based on the Laurent matrix expansion at s = =of the inverse of A(s), i.e. A(s)1, and (b) in a waysimilar to the one presented by Gantmacher (1959). 相似文献
234.
Irregular sampling, Toeplitz matrices, and the approximation of entire functions of exponential type
In many applications one seeks to recover an entire function of exponential type from its non-uniformly spaced samples. Whereas the mathematical theory usually addresses the question of when such a function in can be recovered, numerical methods operate with a finite-dimensional model. The numerical reconstruction or approximation of the original function amounts to the solution of a large linear system. We show that the solutions of a particularly efficient discrete model in which the data are fit by trigonometric polynomials converge to the solution of the original infinite-dimensional reconstruction problem. This legitimatizes the numerical computations and explains why the algorithms employed produce reasonable results. The main mathematical result is a new type of approximation theorem for entire functions of exponential type from a finite number of values. From another point of view our approach provides a new method for proving sampling theorems.
235.
Klaus Bö hmer Willy Govaerts Vladimí r Janovský . 《Mathematics of Computation》1999,68(227):1097-1108
A numerical tool for the detection of degenerated symmetry breaking bifurcation points is presented. The degeneracies are classified and numerically processed on -D restrictions of the bifurcation equation. The test functions that characterise each of the equivalence classes are constructed by means of an equivariant numerical version of the Liapunov-Schmidt reduction. The classification supplies limited qualitative information concerning the imperfect bifurcation diagrams of the detected bifurcation points.
236.
On the distribution of the length of the longest increasing subsequence of random permutations 总被引:18,自引:0,他引:18
Jinho Baik Percy Deift Kurt Johansson 《Journal of the American Mathematical Society》1999,12(4):1119-1178
The authors consider the length, , of the longest increasing subsequence of a random permutation of numbers. The main result in this paper is a proof that the distribution function for , suitably centered and scaled, converges to the Tracy-Widom distribution of the largest eigenvalue of a random GUE matrix. The authors also prove convergence of moments. The proof is based on the steepest descent method for Riemann-Hilbert problems, introduced by Deift and Zhou in 1993 in the context of integrable systems. The applicability of the Riemann-Hilbert technique depends, in turn, on the determinantal formula of Gessel for the Poissonization of the distribution function of .
237.
238.
该文研究空间Beltrami方程的推广形式,即双特征Beltrami方程.利用外微分形式与矩阵的外代数等工具,将双特征Beltrami方程转化为一个非齐次的狆 调和方程,转化过程中只用到加于特征矩阵的一致椭圆型条件.然后验证了算子犃满足的条件:Lipschitz型条件、单调不等式、齐次性条件以及算子犅满足的控制增长条件.并利用得到的狆 调和方程,给出了双特征Beltrami方程广义解分量函数的弱单调性结果. 相似文献
239.
Hamparsum Bozdogan Stanley L. Sclove 《Annals of the Institute of Statistical Mathematics》1984,36(1):163-180
Summary Multi-sample cluster analysis, the problem of grouping samples, is studied from an information-theoretic viewpoint via Akaike's
Information Criterion (AIC). This criterion combines the maximum value of the likelihood with the number of parameters used
in achieving that value. The multi-sample cluster problem is defined, and AIC is developed for this problem. The form of AIC
is derived in both the multivariate analysis of variance (MANOVA) model and in the multivariate model with varying mean vectors
and variance-covariance matrices. Numerical examples are presented for AIC and another criterion calledw-square. The results demonstrate the utility of AIC in identifying the best clustering alternatives.
This research was supported by Office of Naval Research Contract N00014-80-C-0408, Task NR042-443 and Army Research Office
Contract DAAG 29-82-K-0155, at the University of Illinois at Chicago. 相似文献
240.
Several new constructions for difference matrices are given. One classof constructions uses pairwise balanced designs to develop newdifference matrices over the additive group of GF (q). A second class of constructions gives difference matrices overgroups whose orders are not (necessarily) prime powers. 相似文献