Discrete Memristor and Discrete Memristive Systems

In this paper, we investigate the mathematical models of discrete memristors based on Caputo fractional difference and G–L fractional difference. Specifically, the integer-order discrete memristor is a special model of those two cases. The “∞”-type hysteresis loop curves are observed when input is the bipolar periodic signal. Meanwhile, numerical analysis results show that the area of hysteresis decreases with the increase of frequency of input signal and the decrease of derivative order. Moreover, the memory effect, characteristics and physical realization of the discrete memristors are discussed, and a discrete memristor with short memory effects is designed. Furthermore, discrete memristive systems are designed by introducing the fractional-order discrete memristor and integer-order discrete memristor to the Sine map. Chaos is found in the systems, and complexity of the systems is controlled by the parameter of the memristor. Finally, FPGA digital circuit implementation is carried out for the integer-order and fractional-order discrete memristor and discrete memristive systems, which shows the potential application value of the discrete memristor in the engineering application field.     

Computation of the locus crossing point location of MC circuit

In this paper, the crossing point property of the i-v hysteresis curve in a memristor-capacitor （MC） circuit is analyzed. First, the ideal passive memristor on the crossing point property of i-v hysteresis curve is studied. Based on the analysis, the analytical derivation with respect to the crossing point location of MC circuit is given. Then the example of MC with linear memristance-versus-charge state map is demonstrated to discuss the drift property of cross-point location, caused by the frequency and capacitance value.     

界面效应调制忆阻器研究进展

忆阻器因其优异的非易失存储特性,且具有结构简单、存储速度快、能耗低、集成度高等优势,在新型电子器件研究领域引起了广泛关注.本文从忆阻器结构出发,对忆阻器主要材料、机理等进行了综述,介绍了忆阻器在电子电路及人工智能等领域的研究进展,重点讨论了界面效应对忆阻行为及性能改善等方面的重要作用,提出了界面纳米点嵌入结构对优化忆阻性能的显著效果,并分析了忆阻器可能的发展趋势.     

改进型细胞神经网络实现的忆阻器混沌电路

在通用细胞神经网络单元的基础上,本文利用忆阻器本身的非线性实现了一种改进型细胞神经网络单元.通过连接4个改进的细胞神经网络单元导出了一种基于状态控制细胞神经网络的忆阻器混沌电路.为了验证该方法的正确性,采用通用的电子器件构建了一个忆阻器的模拟等效电路,并对提出的电路进行了实验分析.实验结果与数值仿真结果的一致性表明采用改进型的细胞神经网络可以有效地实现忆阻器混沌电路.     

基于线性模型的自适应优化去雾算法

针对线性传输算法中透射率和大气光估计不足问题,提出一种基于线性模型的自适应优化去雾算法。利用边缘信息模型来增强初始透射率图的细节信息,使得复原后图像边缘区域细节更丰富;根据暗通道先验,得到自适应优化透射率,更好地处理包含景深区域图像;采用局部大气光估计方法代替四叉树方法,避免大气光估计不准确问题,并结合物理模型恢复图像。仿真实验在matlab2014中进行,实验结果表明,该算法具有较好的有效性和时效性。     

Mapping equivalent approach to analysis and realization of memristor-based dynamical circuit

A novel mapping equivalent approach is proposed in this paper, which can be used for analyzing and realizing a memristor-based dynamical circuit equivalently by a nonlinear dynamical circuit with the same topologies and circuit parameters. A memristor-based chaotic circuit and the corresponding Chua’s chaotic circuit with two output differentiators are taken as examples to illustrate this approach. Equivalent dynamical analysis and realization of the memristor-based chaotic circuit are performed by using Chua’s chaotic circuit. The results indicate that the outputs of memristor-based chaotic circuit and the corresponding outputs of Chua’s chaotic circuit have identical dynamics. The proposed approach verified by numerical simulations and experimental observations is useful in designing and analyzing memristor-based dynamical circuits.     

线阵CCD相机MTF的系统模型估计法与图像复原

线阵推扫CCD图像在获取与传输过程中产生退化。针对其复原问题,从图像降质机理的角度,提出用系统模型法估计MTF,并使用维纳滤波、Lucy-Richardson迭代法等方法对大气状况较好时的实验图像进行复原,采用复原图像的MTF曲线和MTFA(MTF area)等指标评价复原图像质量,并与从图像上提取PSF的图像估计法进行比较。实验结果表明,系统模型法能够更简便、准确地估计出MTF,进而取得良好的复原效果。     

基于GLS模型的光照鲁棒性人脸的识别

针对线性子空间模型在处理具有阴影的人脸图像时出现的不足之处,提出了GLS模型,并将其用于不同光照下的人脸识别。按照测试图像与正确模型间距离尽可能小的原则构造了一个确定最优分组数和子空间维数的标准;采用SVD方法和K平均聚类法将像素分组,并确定每个分组的线性子空间模型;计算测试图像到每个GLS模型中所有分组的线性子空间模型的距离之和,进而识别人脸图像。经假设检验统计表明,基于该模型的方法在处理不同光照下的人脸图像时,效果明显优于其他方法。     

基于一阶广义忆阻器的文氏桥混沌振荡器研究

通过在文氏桥振荡器中引入广义忆阻器和LC吸收网络,提出了一种忆阻文氏桥混沌振荡器.建立了忆阻文氏桥混沌振荡器的动力学模型,研究了它的平衡点和稳定性,进一步开展了电路元件参数变化时的动力学行为分析.研究发现,忆阻文氏桥混沌振荡器有3个确定的平衡点,其稳定性取决于电路元件参数,当参数发生变化时,存在周期振荡、混沌振荡、快慢效应等复杂的非线性现象.实验电路简单易制作,实验波形和数值仿真一致,较好地验证了理论分析结果.     

基于线性分离的自治混沌系统的投影同步

分析了自治混沌系统的投影同步问题.基于线性系统的稳定判定准则，提出一种新的线性分离的同步方法，并采用该方法实现了Lorenz系统，Rssler系统和超混沌Chen系统的投影同步.数值模拟进一步验证了所提出方案的有效性. 关键词： 投影同步 自治混沌系统 线性分离