Real-time removal of ocular artifacts from EEG based on independent component analysis and manifold learning

Frequent occurrence of ocular artifacts leads to serious problems in interpreting and analyzing the electroencephalogram (EEG). In the present paper, a novel and robust technique is proposed to eliminate ocular artifacts from EEG signals in real time. Independent Component Analysis (ICA) is used to decompose EEG signals. The features of topography and power spectral density of those components are extracted. Moreover, we introduce manifold learning algorithm, a recently popular dimensionality reduction technique, to reduce the dimensionality of initial features, and then those new features are fed to a classifier to identify ocular artifacts components. A k-nearest neighbor classifier is adopted to classify components because classification results show that manifold learning with the nearest neighbor algorithm works best. Finally, the artifact removal method proposed here is evaluated by the comparisons of EEG data before and after artifact removal. The results indicate that the method proposed could remove ocular artifacts effectively from EEG signals with little distortion of the underlying brain signals and be satisfied the real-time application.     

Using a Trust Inference Model for Flexible and Controlled Information Sharing During Crises

The fluid, urgent nature of crises requires flexible, responsive information sharing. Recent studies show, however, that in business catastrophes and other kinds of crises conventional access control mechanisms favor security over flexibility. Our work addresses these seemingly contradictory needs for security and flexibility and designs a trust inference model based on fuzzy logic, a model that can be used with pervasive computing technologies using sensors and mobile devices. Drawing upon research on trust, we design a trust inference model using attributes of affiliation, task performance, and urgency; apply the model to a known crisis; discuss implementation issues; and explore issues for further research. This article is dedicated to Alan Jarman, a founding influence in the Journal of Contingencies and Crisis Management who died in Canberra 15 July 2010. Alan's quantitative, engineering background and his long standing commitment to improving crisis decision making prompted him to encourage our applying fuzzy logic to crisis information sharing. We are grateful for Alan's encouragement and advice.     

基于JZ863模块无线遥控电路的设计

该文以家庭电器和灯光智能化控制等方面的需求为例,介绍一种以JZ863为数据传输模块,基于89C2051单片机设计的无线遥控电路设计方案。与编码电路芯片设计的遥控电路相比,外围电路简单,功耗低,编程容易,可靠性高,扩展功能强。     

一种高性能网络游戏服务器架构设计

网络游戏一般采用C/S结构,服务器架构设计是成功开发一款网络游戏的关键,本文对高性能网络游戏服务器架构设计进行了深入地研究。网络游戏服务器的物理结构一般分成区和组,一个区会包括多组服务器,本文设计出的服务器组架构包括LoginGate、LoginServer、GameGate、GameServer、DBServer和MServer等服务器。     

改进的Gabor滤波算法在指纹识别中的应用

指纹自动识别系统中图像的处理和匹配算法在系统的设计中起了尤为重要的作用,本文对Gabor滤波算法进行了简化,同时引入了HGF（Half Gabor Filter）对指纹图像进行了增强处理。实验结果表明经过这种改进的Gabor滤波算法提高了图像的处理速度,并很好的保留纹线的关键信息。     

基于JFreeChart绘制Web统计图表的设计与实现

本文在JFreeChart的基础上,通过设计模式的引入,提出了一种更加方便的基于JFreeChart绘制Web统计图表的设计与实现,这让开发人员不必再过多的关注JFreeChart API,而能抽出更多的时间和精力关注业务逻辑。     

Delay‐dependent robust H∞ control for uncertain stochastic time‐delay systems

This paper investigates the robust H_∞ control problem for stochastic systems with a delay in the state. Sufficient delay‐dependent conditions for the existence of state‐feedback controllers are proposed to guarantee mean‐square asymptotic stability as well as the prescribed H_∞ performance for the closed‐loop systems. Moreover, the results are further extended to the stochastic time‐delay systems with parameter uncertainties, which are assumed to be time‐varying norm‐bounded appearing in both the state and the input matrices. The appealing idea is to partition the delay, which differs greatly from the most existing results and reduces conservatism by thinning the delay partitioning. Numerical examples are provided to show the advantages of the proposed techniques. Copyright © 2009 John Wiley & Sons, Ltd.     

Exponential stability and exponential stabilization of singularly perturbed stochastic systems with time‐varying delay

In this paper, the problems of exponential stability and exponential stabilization for linear singularly perturbed stochastic systems with time‐varying delay are investigated. First, an appropriate Lyapunov functional is introduced to establish an improved delay‐dependent stability criterion. By applying free‐weighting matrix technique and by equivalently eliminating time‐varying delay through the idea of convex combination, a less conservative sufficient condition for exponential stability in mean square is obtained in terms of ε‐dependent linear matrix inequalities (LMIs). It is shown that if this set of LMIs for ε=0 are feasible then the system is exponentially stable in mean square for sufficiently small ε?0. Furthermore, it is shown that if a certain matrix variable in this set of LMIs is chosen to be a special form and the resulting LMIs are feasible for ε=0, then the system is ε‐uniformly exponentially stable for all sufficiently small ε?0. Based on the stability criteria, an ε‐independent state‐feedback controller that stabilizes the system for sufficiently small ε?0 is derived. Finally, numerical examples are presented, which show our results are effective and useful. Copyright © 2010 John Wiley & Sons, Ltd.     

A new design of delay‐dependent robust ℋ︁∞ filtering for continuous‐time polytopic systems with time‐varying delay

This paper revisits the problem of delay‐dependent robust ?_∞ filtering design for a class of continuous‐time polytopic linear systems with a time‐varying state delay. Based on a newly developed parameter‐dependent Lyapunov–Krasovskii functional combined with Projection Lemma and an improved free‐weighting matrix technique for delay‐dependent criteria, a new sufficient condition for robust ?_∞ performance analysis is first derived and then the filter synthesis is developed by using a simple matrix inequality linearization technique. It is shown that the desired filters can be constructed by solving a set of linear matrix inequalities. Finally, two simulation examples are given to show the effectiveness and less conservatism of the proposed method in comparison with the existing approaches. Copyright © 2009 John Wiley & Sons, Ltd.