球对称分布一些子类的特征函数

本文用统一的方法给出了对称Kotz型分布,多元PearsonⅡ分布和椭球logistic对称分布.我们的结果是Iyenger and Tong的结果的推广,另外我们得到了PearsonⅡ型的特征函数的另一种形式.同时,我们讨论了相关的问题.     

Root n bandwidths selectors in multivariate kernel density estimation

Based on a random sample of size n from an unknown d-dimensional density f, the problem of selecting the bandwidths in kernel estimation of f is investigated. The optimal root n relative convergence rate for bandwidth selection is established and the information bounds in this convergence are given, and a stabilized bandwidth selector (SBS) is proposed. It is known that for all d the bandwidths selected by the least squares cross-validation (LSCV) have large sample variations. The proposed SBS, as an improvement of LSCV, will reduce the variation of LSCV without significantly inflating its bias. The key idea of the SBS is to modify the d-dimensional sample characteristic function beyond some cut-off frequency in estimating the integrated squared bias. It is shown that for all d and sufficiently smooth f and kernel, if the bandwidth in each coordinate direction varies freely, then the multivariate SBS is asymptotically normal with the optimal root n relative convergence rate and achieves the (conjectured) lower bound on the covariance matrix.Part of the research was done while the first author was visiting the Institute of Statistical Science, Academia Sinica, Taipei, Taiwan. This work was supported by grant NSC-89-2118-M-006-011, NSC-90-2118-M-006-013 and NSC-91-2118-M-006-005 of National Science Council of Taiwan, R.O.C.     

A fixed point localization formula for the Fourier transform of regular semisimple coadjoint orbits

Let be a Lie group acting on an oriented manifold M, and let ω be an equivariantly closed form on M. If both and M are compact, then the integral is given by the fixed point integral localization formula (Theorem 7.11 in Berline et al. Heat Kernels and Dirac Operators, Springer, Berlin, 1992). Unfortunately, this formula fails when the acting Lie group is not compact: there simply may not be enough fixed points present. A proposed remedy is to modify the action of in such a way that all fixed points are accounted for.Let be a real semisimple Lie group, possibly noncompact. One of the most important examples of equivariantly closed forms is the symplectic volume form dβ of a coadjoint orbit Ω. Even if Ω is not compact, the integral exists as a distribution on the Lie algebra . This distribution is called the Fourier transform of the coadjoint orbit.In this article, we will apply the localization results described in [L1,L2] to get a geometric derivation of Harish-Chandra's formula (9) for the Fourier transforms of regular semisimple coadjoint orbits. Then, we will make an explicit computation for the coadjoint orbits of elements of which are dual to regular semisimple elements lying in a maximally split Cartan subalgebra of .     

模糊控制器动态性能的改善

模糊逻辑控制具有算法简单、鲁棒性强等特点，但动态响应品质不易改善：瞬志响应与稳态特性难于兼顾。本文从工程实践中总结出一种可行的模糊控制算法，基于此算法开发出的模糊控制器响应迅速、调节精细，小批量推广应用的效果令人满意。     

带下降方向搜索的总极值方法

本文将文[1]提出的一类求总极值方法与非线性规划的下降方法相结合,提出一类带下降方向搜索的求总极值方法,并且证明了这类方法具有线性和超线性收效率.     

典型域上R—W多项式及内函数的存在性

该文给出了多复变四类典型域（m，n）,（n）,(2k),（3）及(n)上的R－W型多项式,并证明了这些区域上内函数的存在性．     

解大型非对称特征问题的精化块不完全正交化算法

0引言 块Arnoldi方法~[5]是解大型非对称特征值问题的正交投影方法，然而Jia~[3]的分析表     

One way to solve the parametric quadratic programming problem

A method is presented for the solution of the parametric quadratic programming problem by the use of conjugate directions. It is based on the method for quadratic programming proposed by the author in [1].While engaged in this research the author had a part-time post with the Manpower Services Commission.     

Design of Cylindrical Conformal Millimeter-Wave Microstrip Antennas with Broad Beamwidth

This paper describes the design of a novel cylindrical millimeter-wave microstrip antenna (MA) with broad beamwidth by means of isotropic transformation (IT). A planar millimeter-wave antenna with broad beamwidth is designed first, and then IT is used to design a conformal one based on the planar structure. In addition, phased array with eight present elements has been designed as an example. Finally, numerical results are given to show that the present antenna possesses broad beamwidth and its array is of large scanning angle, which also verify the validity of the method of IT.