An Improved Composite Multiscale Fuzzy Entropy for Feature Extraction of MI-EEG

Motor Imagery Electroencephalography (MI-EEG) has shown good prospects in neurorehabilitation, and the entropy-based nonlinear dynamic methods have been successfully applied to feature extraction of MI-EEG. Especially based on Multiscale Fuzzy Entropy (MFE), the fuzzy entropies of the τ coarse-grained sequences in τ scale are calculated and averaged to develop the Composite MFE (CMFE) with more feature information. However, the coarse-grained process fails to match the nonstationary characteristic of MI-EEG by a mean filtering algorithm. In this paper, CMFE is improved by assigning the different weight factors to the different sample points in the coarse-grained process, i.e., using the weighted mean filters instead of the original mean filters, which is conductive to signal filtering and feature extraction, and the resulting personalized Weighted CMFE (WCMFE) is more suitable to represent the nonstationary MI-EEG for different subjects. All the WCMFEs of multi-channel MI-EEG are fused in serial to construct the feature vector, which is evaluated by a back-propagation neural network. Based on a public dataset, extensive experiments are conducted, yielding a relatively higher classification accuracy by WCMFE, and the statistical significance is examined by two-sample t-test. The results suggest that WCMFE is superior to the other entropy-based and traditional feature extraction methods.     

信息安全风险评估的模糊多准则决策方法

基于ISO/IEC17799标准建立了一个综合的信息系统风险分析框架,并运用模糊多准则决策(FMCDM)方法计算信息安全风险,根据风险等级矩阵(RLM)对信息资产风险进行级别划分,最终建立评估信息资产相关风险的完整模型。     

利用静电学和测量数据对碳纳米管膜场致发射规律的定量分析

碳纳米管膜的场致发射电流密度仅由它表面的宏观电场决定，无论其表面形状是平的还是半球状的。对于理想的平行板电极系统，其表面电场强度均匀（UId），发射电流密度、总电流与发射面积成正比：对于半球一平面电极系统半球形的阴极存在一个宏观场增强因子ks，一个与两极距离和球半径之比（d/r）相关的函数，其表面的平均场强为ks U/d。对于d/r=0，ks=1，d≥r的情况，ks接近于常数。对于10〈d／r〈100的情况，存在一个经验的表达式：ks=1＋0．15d/s=0．005（d／r）^2。在引入ks后，不同作者给出的平面电极系统和半球一平面电极系统碳纳米管膜的场致发射电流I与宏观表面电场强度E的关系都可以近似用-经验公式描述：I=a（E-Eo）^b，a，b为常数。该经验公式可为稳定生产的CNT膜片应用产品设计提供方便。     

Scaling properties of fracture surfaces on glass strengthened by ionic exchange

In this work the results of the statistical topometric analysis of fracture surfaces of soda-lime-silica glass with and without ionic exchange treatment are reported. In this case, the mechanism of substitution is K⁺-Na⁺. atomic force microscopy (AFM) was employed to record the topometric data from the fracture surface. The roughness exponent (ζ) and the correlation length (ξ) were calculated by the variable bandwidth method. The analysis for both glasses (subjected and non-subjected to ionic exchange) for ζ shows a value ∼0.8, this value agrees well with that reported in the literature for rapid crack propagation in a variety of materials. The correlation length shows different values for each condition. These results, along with those of microhardness indentations suggest that the self-affine correlation length is influenced by the complex interactions of the stress field of microcracks with that resulting from the collective behavior of the point defects introduced by the strengthening mechanism of ionic exchange.     

An Improved Immune Genetic Algorithm for Solving the Optimization Problems of Computer Communication Networks

1　IntroductionIndesigningacomputercommunicationnet work ,thenetworkaveragedelayisanimportantpa rameterinthenetworkperformance .Inthispaper,weonlyconsiderM /M/1networks,whichmeansthatthemessageprocessingtimeisaprobabilisticdensityfunctionwithnegativepower,thegroupar rivalandsendingisofPoissiondistributionwithasinglequeue .Supposethatthenetworktopologicalstructureandtheestimatesoftheexternaltrafficrequirementsaregiven ,howtoselecttheoptimalroutestobeusedbythecommunicatingnodesinthenetworksoast…     

一个基于相邻像素兼容度的模糊加权平均滤波器

在文献[1]的基础上，提出几个改进的模糊加权平均滤波器。本文的方案不仅同时考虑了相邻像素对中心像素的兼容性以及中心像素对相邻像素的兼容性，而且还考虑到了权系数对局部环境的适应性。实验结果表明，该方法相比文献[1]中的模糊加权平均滤波器以及标准的均值滤波器、中值滤波器在噪声消除与边缘保留方面具有更好的性能。     

多传感器目标的模糊识别

根据模糊理论，采用信息融合技术和模糊识别技术，讨论了在多类传感器网内进行多目标模糊识别的一般原理和方法。     

一类连续模糊动态系统控制方法在Furuta摆中的应用

为了研究Furuta摆在倒立点附近的稳定控制问题，采用基于T-S模糊模型的一类连续模糊动态系统控制方法，首次进行Furuta摆的模糊状态空间建模，并采用模糊切换的思想，设计了Furuta摆在倒立点附近的稳定控制器，进而分析了系统稳定性。与已有的方法相比，该方法的优点是稳定区域大、调节时间短。数字仿真结果验证了方法的有效性。     

双波长稳频CO_2激光模糊控制系统的建模与优化

报导一种模糊逻辑控制系统的建模与优化方法。以此方法设计的模糊逻辑控制器，用于双波长稳频ＣＯ２激光器的控制得到令人满意的结果。     

离心力场作用下多孔介质中强制对流换热的研究

对离心流化床中空气通过多孔物料层的强制对流换热进行了理论和实验研究。获得了气流和物料间强制对流换热的准则关联式。研究结果表明,在气流速度和温度梯度方向一致的条件下,强制对流换热比通常的边界层强制对流换热有所强化,其换热的准则关联式具有 Nu=CRePr的线性形式。从而验证了改变气流方向和热流密度矢量之间夹角可以强化换热的这一强化传热新原理。