远程VPN接入技术的选择浅析

VPN技术种类繁多,但是不同的用户有不同的需求,本文依据当前文献中出现的不同VPN技术,在分析了它们各自的技术特点后,提出了一种远程用户接入本地网络时的VPN方案的选择方法。     

量子密码在无线局域网中的安全研究

本文通过对量子密码BB84协议及IEEE802.11i认证协议的分析与讨论,深入研究了802.11i密钥管理机制中的4次握手,利用量子密码安全的优势与IEEE802.11i无线网络相结合,提出量子握手,为无线网络中数据的通信安全提供保障。     

Improved exponential stability criteria for uncertain neutral system with nonlinear parameter perturbations

This paper investigates the problem of robust exponential stability for neutral systems with time-varying delays and nonlinear perturbations. Based on a novel Lyapunov functional approach and linear matrix inequality technique, a new delay-dependent stability condition is derived. Since the model transformation and bounding techniques for cross terms are avoided, the criteria proposed in this paper are less conservative than some previous approaches by using the free-weighting matrices. One numerical example is presented to illustrate the effectiveness of the proposed results.     

Constrained multivariable stable predictive control based on Toeplitz equation

A stable constrained multivariable predictive control algorithm based on the Toeplitz predictive equation is presented. An analytical method for transformation between left and right coprime factorization of multivariable system is put forward, and then an unconstrained control law and its stable condition are given. Furthermore, for the constrained multivariable controlled system, a predictive controller and its asymptotically stable condition are presented and proved. Finally, the constrained receding horizon optimization is transformed into a typical linear matrix inequality (LMI) problem and solved. The detailed control algorithm is depicted in a numerical example, and the simulation results reveal the effectiveness and practicability of the presented algorithm. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

Passive location of the nonlinear systems with fuzzy uncertainty

With the merits such as hiding receiving, easy-deploying and high security, passive location has attracted more and more attention and plays an important role in fields as diverse as navigation, location, and tracking, etc. However, the current filters models for passive location methods are most under the framework of the probability theory, thus they can not estimate the state in some passive location with fuzzy uncertainty accurately. Although the fuzzy extended Kalman filter (FEKF) can deal with the fuzzy uncertainty, it unavoidably introduces truncation error. In this paper, based on the FEKF and the iterated extended Kalman filter (IEKF) principle, a new fuzzy passive location model is built, and moreover, an iterated fuzzy extended Kalman filter (IFEKF) is proposed for estimating the target state. Compared to the FEKF and the IEKF, the proposed algorithm can not only reduce the truncation error, but also deal with fuzzy uncertainty. Moreover, it is proved that the IFEKF update is an application of the Gauss–Newton method. Then, a fuzzy passive location algorithm is proposed. Simulation results demonstrate that the proposed approach has better estimation precision than the traditional fuzzy extended Kalman filter.     

Dynamics analysis of a new simple chaotic attractor

In this paper, a novel simple chaotic system is discussed. Some basic dynamical properties, such as Lyapunov exponents, Poincaré mapping, fractal dimension, bifurcation diagram, continuous spectrum and chaotic dynamical behaviors of the novel chaotic system are studied, either numerically or analytically. The obtained results show clearly that the system discussed in this Letter is a novel chaotic system and deserves a further detailed investigation.     

复杂装备故障预测与健康管理系统初探

故障预测与健康管理(PHM)系统是新型维修保障模式—自主后勤保障的重要组成部分,对提高复杂装备的战备完好性和降低维修成本具有重要意义;首先介绍PHM系统基本概念及主要组成,并对在复杂装备全寿命周期实施PHM的必要性进行分析;综合论述了PHM系统实现中的关键支撑技术:基于RCM分析的方案设计、基于匹配度的健康状态评估和基于剩余寿命预测的维修决策;最后给出了PHM系统在无人机装备中的应用实例;国内外应用情况表明,PHM系统可显著提高维修保障效率并降低维修保障费用,可实现经济可承受性目标。     

导引头电子舱自动测试系统中波形相似性度量问题的研究

针对某型号导引头电子舱自动测试系统中波形合格性测试的特殊应用需求,在对已有相似性度量算法进行研究的基础上,提出了适合于本系统应用的波形相似性度量方案;该方案将向量夹角余弦算法和平均绝对差算法相结合,分别从整体和局部对被测波形进行相似度测量;此外还引入了动态滑动窗口算法,解决了被测波形与模板波形的相位对齐问题;对比实验结果表明,与区域相关法、动态时间归正法以及骨架树匹配法相比,该相似性度量方案更加有效、实用.     

WSN中基于改进自适应遗传算法的移动代理路由算法

文章针对无线传感器网络能量消耗和延时问题,结合移动代理路由策略,提出了一种改进型自适应遗传算法,利用此算法求出移动代理在网络中的最佳迁移节点序列,以达到优化网络效果.通过仿真实验结果表明,与标准遗传算法相比,此算法具有更小的网络能量消耗和延时.     

论两汉文化影响下的徐州公共艺术设计

本文通过分析两汉文化相关的徐州公共艺术建设现状,对两汉文化在徐州公共艺术创作中形式的运用进行深入的论证,立足本土,寻求与城市历史文化相适应的城市公共艺术形式。确立徐州公共艺术布局和主题风格的定位,指出当代徐州公共艺术设计要注重发掘和利用地域文化资源,设计高水平的公共艺术作品。