Riesz bases and exact controllability of C0-groups with one-dimensional input operators

This paper considers linear infinite dimensional systems with C₀-group generators and one-dimensional admissible input operators. The exact controllability and Riesz basis generation property are discussed. The corresponding results of Jacob and Zwart (Advances in Mathematical Systems Theory, Birkhäuser, Boston, MA, 2000) under the assumption of algebraic simplicity for eigenvalues of the generator are generalized to the case in which the eigenvalues are allowed to be algebraically multiple but with a uniform bound on the multiplicity.     

Orthogonal polynomials and natural exponential families

Summary There exist several different characterizations of the class of quadratic natural exponential families onR, two of which use orthogonal polynomials. In Feinsilver (1986), the polynomials result from the derivation of the probability densities while Meixner (1934) adopts an exponential generating function. In this paper, we consider multidimensional extensions of their results which still yield quadratic or simple quadratic natural exponential families.     

走向未来的电子图书馆

简要介绍未来电子图书馆的建立基础、功能特征和馆员的职责。     

Using Gröbner bases for finding the logarithmic part of the integral of transcendental functions

We show that Czichowski’s algorithm for computing the logarithmic part of the integral of a rational function can be carried over to a rather general class of transcendental functions. Also an asymptotic bound on the number of field operations needed is given.     

虚拟蜜网核心功能剖析与实例部署

传统蜜网硬件利用率低、配置复杂、管理难度大等缺点日渐凸显,如何解决这些问题越来越受到研究人员的关注。针对蜜网当前面临的问题,提出了使用虚拟技术构建蜜网的必要性。通过对蜜网关键技术的研究,分析并给出蜜网核心功能在虚拟系统中的工作流程,在此基础上设计并实现了一种虚拟蜜网的解决方案。实验结果表明,建立的虚拟蜜网工作良好,并在一定程度上解决了传统蜜网在硬件利用率、配置和管理等方面存在的问题。     

Analytical solution of the linear fractional system of commensurate order

A useful representation of fractional order systems is the state space representation. For the linear fractional systems of commensurate order, the state space representation is defined as for regular integer state space representation with the state vector differentiated to a real order. This paper presents a solution of the linear fractional order systems of commensurate order in the state space. The solution is obtained using a technique based on functions of square matrices and the Cayley-Hamilton theorem. The technique developed for linear systems of integer order is extended to derive analytical solutions of linear fractional systems of commensurate order. The basic ideas and the derived formulations of the technique are presented. Both, homogeneous and inhomogeneous cases with usual input functions are solved. The solution is calculated in the form of a linear combination of suitable fundamental functions. The presented results are illustrated by analyzing some examples to demonstrate the effectiveness of the presented analytical approach.     

城市·生态·文化——监利县西门公司规划设计札记

介绍湖北监利县西门公园的规划设计,论述在城市公园的规划设计中立足于体现娱乐性、休闲性和文化性等综合功能,以及生态原则和文化特征是具体落实经济效益、社会效益和环境效益的一种较为切合实际的规划设计方向。     

用于快速形状匹配的精确型高度函数特征描述

在形状匹配过程中为了提升高度函数描述子的检索精度和对边界噪声与局部变形的鲁棒性,本文提出了一种精确型高度函数特征描述算法。首先提取目标形状外轮廓,构造轮廓采样点的精确型高度函数描述子并进行特征降维,接着利用优化后的并行动态规划进行形状匹配,最后引入形状复杂度分析提升匹配效果。基于点的几何特征显著性,提出形状精度理论,进一步分析局部形变与边缘噪声对形状特征描述的影响。在MPEG-7数据库、Swedish Leaf数据库、Tools数据库和ETH-80大型3D数据库上进行匹配实验以及在Kimia99数据库上进行抗噪实验,实验结果表明:本文提出的算法效率高,匹配时间仅为高度函数描述子的12.5%,在MPEG-7和ETH-80上的检索率最高分别为90.38%和90.07%;在Swedish Leaf和Tools上,检索精度最高分别为95.07%和94.86%,检索性能和鲁棒性均优于高度函数和其他重要算法;在添加噪声的Kimia 99上,该算法的抗噪性能优于高度函数描述子,即使在噪声水平为2.0的情况下,依旧能保持91.92%的检索率。本文提出的算法检索精度高,效率高,鲁棒性好,抗噪性强,具有较好的可扩展性,能有效地应用于形状检索领域。     

EMD和CSP融合最优波长空间滤波脑电特征提取方法

基于经验模式分解和共空间模式,结合最优波长空间滤波,提出了三者相结合的特征提取方法。该方法首先利用经验模式分解进行分解,得到固有模态函数,选择合适的固有模态函数进行信号的重构,然后将重构的信号进行最优波长空间滤波变换,得到最优的波长选择信号,再经共空间模式投影映射,提取相应的特征向量,最后利用支持向量机进行分类。运用该方法对9位受试者进行分类结果分析,平均分类准确率在95%以上,实验表明,提出的算法具有较好的分类识别性。     

基于Hash函数和自动恢复技术的网站抗毁系统研究与实现

文章提出了一种基于Hash函数和自动恢复技术的网站抗毁系统模型,介绍了一个基于该模型的“磐石”网站监控与自动恢复系统的组成结构和实现机制。讨论了该系统实现中的一些关键技术,并介绍了该系统的主要功能和特点及典型应用环境。最后给出了该项目今后的工作方向。