一种基于Hash函数的RFID安全认证方法

近年来,射频识别(RFID)技术得到越来越多的应用,随之而来的是各种RFID安全问题。对现有的基于Hash函数的RFID认证协议进行分析,针对现有技术存在的不足,提出了一种基于Hash函数的低成本的RFID双向安全认证方法,该方法只需要进行一次Hash函数计算,且加入了标签ID动态更新机制,通过在后台数据库中存储旧的标签ID解决同步问题,与现有技术相比具有一定的优越性。     

基于互信息波段选择和经验模态分解的高精度高光谱数据分类

在遥感数据处理研究中,高维高光谱数据的冗余信息和噪声严重影响高光谱数据的分类精度,针对此问题提出基于互信息波段选择和经验模态分解的高精度高光谱数据分类算法(MI-EMD-SVM).分别采用基于互信息波段选择方法和经验模态分解实现对高光谱数据的冗余信息处理和特征提取,并获得处理后的高光谱数据X'.采用支持向量机分类算法...     

语音识别的互信息匹配模型及其应用

互信息是随机变量或随机信号之间所携带对方信息的定量描述。语音识别的互信息匹配模型依据互信息理论以及语音信号特征参数统计分析结果而提出,这一模型同时考虑了语音信号的时变发布特征和统计分布特征,能有效地提高同类模式的凝聚度,减少非同类模式间的耦合性。语音识别实验和实际应用表明,互信息匹配模型具有良好的识别精度和很高的运行效率,与其它模式匹配方法相比更适合嵌入式系统的语音识别应用。对互信息匹配模型的原理和特点进行了全面的阐述,并介绍了这一模型在几个语音识别系统中的具体应用。     

Humidity‐Triggered Self‐Healing of Microporous Polyelectrolyte Multilayer Coatings for Hydrophobic Drug Delivery

Layer‐by‐layer (LbL) self‐assemblies have inherent potential as dynamic coatings because of the sensitivity of their building blocks to external stimuli. Here, humidity serves as a feasible trigger to activate the self‐healing of a microporous polyethylenimine/poly(acrylic acid) multilayer film. Microporous structures within the polyelectrolyte multilayer (PEM) film are created by acid treatment, followed by freeze‐drying to remove water. The self‐healing of these micropores can be triggered at 100% relative humidity, under which condition the mobility of the polyelectrolytes is activated. Based on this, a facile and versatile method is suggested for directly integrating hydrophobic drugs into PEM films for surface‐mediated drug delivery. The high porosity of microporous film enables the highest loading (≈303.5 μg cm^?2 for a 15‐bilayered film) of triclosan to be a one‐shot process via wicking action and subsequent solvent removal, thus dramatically streamlining the processes and reducing complexities compared to the existing LbL strategies. The self‐healing of a drug‐loaded microporous PEM film significantly reduces the diffusion coefficient of triclosan, which is favorable for the long‐term sustained release of the drug. The dynamic properties of this polymeric coating provide great potential for its use as a delivery platform for hydrophobic drugs in a wide variety of biomedical applications.     

ZFSD5600/22/35型组合式端头支架研究

ZFSD560 0 /2 2 /35型组合式端头支架属于原煤炭部“九五”重点科研攻关项目“坚硬厚煤层综放开采关键技术研究”第三子专题主要研究内容之一。它是针对大同坚硬厚煤层综放设备配套大、配套空间有限 ,设计的一种新型组合式端头支架 ,该支架首次实现了与转载机互为联动功能 ,它的研究使用成功 ,为我国综放开采端头支护提供了一种新架型。     

金属化有机薄膜电容器的自愈机理及可靠性设计

金属化有机薄膜电容器在制造过程中由于金属化电极发生连续性自愈，致使制造工艺失控。根据自愈机理，采取控制外加压力和电压，恰当选择金属化膜方阻等措施，从而改善工艺，降低废品率。     

A correlation for predicting diffusion coefficients in alkanes

A correlation was developed for predicting limiting mutual diffusion coefficients of gaseous and liquid solutes in normal alkane solvents with carbon numbers ranging from 7 to 28 at temperatures to 570 K. The functional form of the correlation is based on the rough hard sphere theory. The parameters needed in the correlation are the molecular weights and hard sphere diameters of the solute and solvent molecules and molar volume of the solvent. The data used in the development of the correlation included 143 measurements with solute/solvent molecular mass ratios ranging from 0.005 to 2.26 and size ratios ranging from 0.3 to 1.3. The average absolute error in predictions was only 6.3%. When the correlation was used to predict literature values for binary n-alkane systems, the average absolute error was 16.7%.     

基于矩量法的天线阵互阻抗分析

利用矩量法对天线阵阵元的互阻抗进行了分析。首先对线天线进行分析建模,计算出天线上的电流分布的线密度,并由此得到互阻抗。通过算例验证,这种方法准确有效,可在工程中快速分析互耦对天线方向图的影响,具有很强的工程适应性。     

基于MATLAB的超声检测自动判伤算法研究

为了实现MATLAB对超声波检测的自动判伤以及简化图像处理过程,以火车轮对为例,对火车轮对的超声检测B扫描图进行了分类处理。运用基于互信息的图像配准方法对复杂背景图像进行处理,并对基于互信息配准得到的结果进行求补集,最后经过MATLAB工具实现对图像中缺陷的判别并予以标示,显示缺陷的位置信息,成功地实现了超声检测中缺陷的自动判伤,提高了超声检测中的判伤效率。