基于稳健信息隐藏的脆弱水印

Block-wise fragile watermarks can be used to reveal maliciously tampered areas in multimedia products. However a forged content containing a cloned fragile watermark can be constructed by using a series of watermarked data. To defeat this type of counterfeit attack, a novel fragile watermarking technique is proposed in which different pseudo-random data are selected for different host products, and the generated fragile watermark is dependent upon the selected information. While inserting the fragile watermark, the     

具有滞后摄动的线性切换系统的二次鲁棒稳定性问题

讨论了具有时滞摄动的线性切换系统的二次鲁棒稳定性问题,利用单Lyapunov函数构造了一个切换律,使系统稳定,所得结果以矩阵不等时表示,便于实现。     

Continuous robust tracking controllers for a class of uncertain nonlinear dynamical systems

Robust tracking controller for a class of uncertain nonlinear dynamical systems, which are linearizable by input-output feedback with matching uncertainties, was investigated. In this study, uniform ultimate bound or uniformly asymptotic stability of tracking errors were obtained by different choice of the control gain. A simulation to determine the effectiveness of the proposed approach showed that the control performance was better than that of VSC (Variable Structure Control). Project(69934030) supported by Natural Science Foundation of China.     

稳定多项式系数的最大扰动量分析

对于一个给定的Hurw itz稳定多项式,分析其系数受到多大的扰动作用多项式仍保持稳定是很有意义的.为此,我们将给出两种求稳定多项式系数最大扰动量的方法.     

On a modification approach to a class of Lyapunov-based robust controllers subject to input constraint

This paper presents an approach to the modification of a class of Lyapunov-based robust controllers when the input constraint needs to be taken into account. The approach shows advantages in enhancing the input utilization and in retaining the stability and the robustness of the original control. The modification comprises two stages. The first stage is to reshape the original control for satisfying the constraint and preserving the original control direction. The second stage is to apply a structure for enhancing the input utilization and retaining the stability and robustness developed in the first stage. In addition, an estimate of the stabilization region is employed to select the design parameters for the local, semiglobal, and global stabilization.     

具多个平衡点的不确定混杂系统输出反馈鲁棒镇定

基于分段二次型Lyapunov函数，给出了具多个平衡点的不确定混杂系统混杂动态输出反馈鲁棒镇定控制器的设计方法，该控制器不仅包含连续动态行为，而且具有逻辑动态，仿真结果表明，本文的设计方法是有效可行的。     

一类MIMO非线性系统的H∞回路成形控制

针对一类多输入多输出非线性系统,基于H∞回路成形控制器设计方法,提出了一种新的鲁棒控制方案.分析了实际工业控制中生产过程的复杂性,运用H∞回路成形理论设计了控制器,总结了H∞回路成形控制器的特点.最后,在MATLAB环境下对某MIMO系统进行了仿真实验,比较了各种控制方案的性能,仿真结果表明该控制方案的优越性.     

基于协方差矩阵重构的稳健波束形成算法

当期望信号导向矢量失配以及采样协方差矩阵中包含期望信号时,传统自适应波束形成器性能会下降。对此问题,提出了一种基于协方差矩阵重构的稳健波束形成算法。该算法首先通过对期望信号和干扰的大致来波方向范围进行积分以估计出导向矢量,然后利用主模式抑制去除信号间多余的相干性,并重构出最终的协方差矩阵。仿真实验表明,该算法提高了期望信号导向矢量失配时的稳健性,降低了对快拍数的敏感性。     

Global exponential robust stability of Cohen-Grossberg neural network with time-varying delays and reaction-diffusion terms

In this paper, the global exponential robust stability is investigated for Cohen-Grossberg neural network with time-varying delays and reaction-diffusion terms, this neural network contains time-invariant uncertain parameters whose values are unknown but bounded in given compact sets. Neither the boundedness and differentiability on the activation functions nor the differentiability on the time-varying delays are assumed. By using general Halanay inequality and M-matrix theory, several new sufficient conditions are obtained to ensure the existence, uniqueness, and global exponential robust stability of equilibrium point for Cohen-Grossberg neural network with time-varying delays and reaction-diffusion terms. Several previous results are improved and generalized, and three examples are given to show the effectiveness of the obtained results.