离散时间的混合时滞耦合神经网络的鲁棒指数同步

讨论了一类离散时间的时滞耦合神经网络的同步问题.在参教不确定的离散时间耦合神经网络中,考虑了变时滞和有限分布时滞.同时,细胞激活函数假设为较Lipschitz奈件更为一般的扇形非线性函数,该函数可以既不可微又不严格单调.通过构造Lyapunov-Krasovskii泛函,运用线性矩阵不等式(LMI)技术,并结合Kronecker积来获得耦合神经网络鲁棒全局指数同步的充分性判据,并且所获得的判据依赖于时滞.最后,对一个实例进行仿真,说明结论的有效性.     

工业技术与资源环境协调发展的实证研究——基于超效率DEA生态效率和省际面板数据

技术环境悖论认为技术同时是环境变化的起源和补救方式,中国工业加速发展不仅带来了技术进步和工业繁荣,也导致了一系列生态问题。本文在测算2007-2011中国各地区超效率生态效率的基础上,利用省际面板数据分析工业技术对生态效率的影响。结果表明：(1)中国的生态效率自东向西逐渐降低,资源环境要素生产率增长主要来源于技术进步;(2)虽然整体上工业自主创新和创新成果转化仍未摆脱粗放特征,但东南沿海地区自主创新对生态效率已呈显著正效应;(3)整体上高技术行业对生态效率的正效应显著,但中西部地区仍应加快完善高技术行业以促进生态正效应显现。     

稳健多元校正方法及其比较研究

本文提出了基于简单中位数法和重复中位数法的四种稳健多元校正方法。介绍了文献中的两种稳健多元校正方法用于比较。提出了一种信息效能指标作为评价标准。     

Robust fault detection for a class of nonlinear time-delay systems

In this paper, the robust fault detection filter (RFDF) design problems are studied for nonlinear time-delay systems with unknown inputs. Firstly, a reference residual model is introduced to formulate the robust fault detection filter design problem as an H_∞ model-matching problem. Then appropriate input/output selection matrices are introduced to extend a performance index to the time-delay systems in time domain. The reference residual model designed according to the performance index is an optimal residual generator, which takes into account the robustness against disturbances and sensitivity to faults simultaneously. Applying robust H_∞ optimization control technique, the existence conditions of the robust fault detection filter for nonlinear time-delay systems with unknown inputs are presented in terms of linear matrix inequality (LMI) formulation, independently of time delay. An illustrative design example is used to demonstrate the validity and applicability of the proposed approach.     

Robust control for discrete-time singular large-scale systems with parameter uncertainty

This paper addresses the problem of robust stabilization for uncertain discrete-time singular large-scale systems with parameter uncertainties. The system under consideration is not necessarily regular. The parameter uncertainties are assumed to be time invariant, but norm-bounded. The purpose of the robust stabilization problem is to design state feedback controllers such that, for all admissible uncertainties, the closed-loop system is regular, causal and stable. In terms of strict LMIs, sufficient conditions for the solvability of the problem is presented, and the parameterization of desired state feedback controllers is also given. A numerical example is given to demonstrate the applicability of the proposed design approach.     

An overview of the applications and solutions of a fundamental matrix equation pair

Equation TA−FT=LC (F is stable) is necessary and sufficient for the output of a feedback compensator (F,L,K_Z,K_y) to converge to a state feedback (SF) signal for a constant K, where (A,B,C,0) is the open loop system and TB is the compensator gain to the open loop system input. Thus, equation TB=0 is (1) the defining condition for this feedback compensator to be an output feedback compensator. Equation TB=0 is also the necessary and sufficient condition to (2) fully realize the critical loop transfer function and robust properties of SF control if K is systematically designed. Furthermore, because B is compatible to the open loop system gain to its unknown inputs and its input failure signals, TB=0 is also necessary for (3) unknown input observers and (4) failure detection and isolation systems. Finally, this equation pair (TA−FT=LC, TB=0) is the key condition of a really systematic and explicit design algorithm for (5) eigenstructure assignment by static output feedback control. This paper reviews the existing solutions of this equation pair, and points out that a general and exact solution is uniquely direct, simple, and decoupled. This paper also points out that these unique features also enable two decisive advantages: (1) the systematic compensator order adjustment and (2) a simple and approximate solution which is general to all systems (A,B,C,0) and which can be simply added to the exact solution whether it exists or not.     

一种基于PIFS的DWT水印算法

本文提出了一种基于分块迭代函数系(PIFS)的小波域水印算法。通过PIFS变换将水印图变换为自相似分形水印图,然后用小波变换进行水印的嵌入、提取。实验证明该算法有良好的鲁棒性,同时保证了水印的不可见性。     

复系数多项式凸组合的稳定性检验

两个给定的同次复系数多项式是Hurwitz稳定的,它们的凸组合是否也是Hurwitz稳定的?本文就此给出了一个检验方法.该方法以结式理论为依据,并应用了Sturm定理,不需求解多项式的根,仅经过有限步的运算就可完成对凸组合的稳定性判别,应用方便.     

基于SURF算法的视频贴片广告图标的检测方法

视频媒体中的广告元素随着商业化步伐日趋增多,媒体市场的监测部门常常需要检测视频中某个广告图标出现的时间位置和存在的时间长度。针对这一需求,一种基于SURF算法的视频贴片广告图标的检测方法被提出。首先详细介绍SURF算法,通过对匹配比的计算等改进,以定量表示图像间的匹配程度,并将改进后的方法引入视频贴片广告的检测工作中,提出了一种检测视频中出现的贴片广告图标的方法,最后使用实际视频作为用例对方法进行验证,效果良好,结果准确。