HPTiO2忆阻线性和非线性模型及其特征分析

为了分析HP TiO2忆阻模型的本质特征,比较基本模型与非线性窗函数模型之间本质特征的差异,概述了几种典型的HP TiO2忆阻非线性窗函数模型的特点,开展了HP TiO2忆阻基本模型的本质特征分析,并对几种非线性窗函数模型的本质特征进行了比较。结果表明,对于任意忆阻初始状态和任意振幅与频率的正弦电流激励,HP TiO2忆阻模型都能呈现出紧磁滞回线特征;不同的非线性窗函数模型的特征受其非线性漂移的影响,所产生的输出电压和忆阻值有着不同的瞬态过渡过程,且忆阻初始状态值越大,非线性漂移影响就越严重,导致部分HP TiO2忆阻模型性能失效。     

一种忆阻器离散混沌映射的设计及FPGA实现

忆阻器是一个无源二端口电子器件,在非线性应用领域具有巨大潜力。忆阻器具有的非线性电压电流特性,可以应用在混沌领域。 Cubic映射是一个比较简单的混沌映射,该文使用忆阻器的非线性特性对Cubic映射进行修改,得到一个新的忆阻器混沌映射,使用DSP Builder 对其进行图形化设计,并研究该混沌映射的基本性能,用FPGA实现该混沌映射。     

Memristor‐based voltage‐controlled relaxation oscillators

This paper introduces two voltage‐controlled memristor‐based reactance‐less oscillators with analytical and circuit simulations. Two different topologies which are R‐M and M‐R are discussed as a function of the reference voltage where the generalized formulas of the oscillation frequency and conditions for oscillation for each topology are derived. The effect of the reference voltage on the circuit performance is studied and validated through different examples using PSpice simulations. A memristor‐based voltage‐controlled oscillator (VCO) is introduced as an application for the proposed circuits which is nano‐size and more efficient compared to the conventional VCOs. Copyright © 2013 John Wiley & Sons, Ltd.     

Novel chaotic behavior in the Muthuswamy–Chua system using Chebyshev Polynomials

In this paper, three kinds of memristors with memristance functions obtained from the Chebyshev polynomials are used in the Muthuswamy–Chua system, which has only three circuit elements: a linear passive inductor, a linear passive capacitor and a nonlinear active memristor. We use multivariable second‐order polynomial functions of current and memristor state for the internal state function of the memristor. This enables our system to generate not only double‐scroll but also four‐scroll attractors. Systematic studies of chaotic behavior in these systems are performed using phase portraits, bifurcation diagrams and Lyapunov exponents. Simulation results show that all these systems exhibit chaotic behavior over a range of control parameters. Copyright © 2014 John Wiley & Sons, Ltd.     

A unified cubic flux‐controlled memristor: theoretical analysis,simulation and circuit experiment

In this paper, a unified cubic flux‐controlled memristor is proposed, and how to choose its parameters to obtain an appropriate memristor is investigated. The relevant frequency band of the exciting source that enables the memristor to keep its characteristics (call it mem‐frequency band) is analyzed, and the matter of high mem‐frequency is also clinched. Based on the trend of their i–v curves versus time, the memristors are divided into two types: P and N. The design, simulations and experiments of the circuits for the presented memristor model are given to describe its dynamical behaviors. The results from simulations and experiments are in good agreement with the theoretical analysis, which are of special guidance for designing such device to satisfy the requirements in practical engineering. Copyright © 2014 John Wiley & Sons, Ltd.     

基于多层忆阻脉冲神经网络的强化学习及应用

人工神经网络（Artificial neural networks,ANNs）与强化学习算法的结合显著增强了智能体的学习能力和效率.然而,这些算法需要消耗大量的计算资源,且难以硬件实现.而脉冲神经网络（Spiking neural networks,SNNs）使用脉冲信号来传递信息,具有能量效率高、仿生特性强等特点,且有利于进一步实现强化学习的硬件加速,增强嵌入式智能体的自主学习能力.不过,目前脉冲神经网络的学习和训练过程较为复杂,网络设计和实现方面存在较大挑战.本文通过引入人工突触的理想实现元件——忆阻器,提出了一种硬件友好的基于多层忆阻脉冲神经网络的强化学习算法.特别地,设计了用于数据——脉冲转换的脉冲神经元;通过改进脉冲时间依赖可塑性（Spiking-timing dependent plasticity,STDP）规则,使脉冲神经网络与强化学习算法有机结合,并设计了对应的忆阻神经突触;构建了可动态调整的网络结构,以提高网络的学习效率;最后,以Open AI Gym中的CartPole-v0（倒立摆）和MountainCar-v0（小车爬坡）为例,通过实验仿真和对比分析,验证了方案的有效性和相对于传统强化学习方法的优势.     

局部有源忆阻器电路及其在HR耦合神经元网络中的应用

该文提出一种新型局部有源忆阻器,使用标准非线性理论分析方法分析其特性,并通过直流伏安特性曲线来证明其局部有源性。此外,将局部有源忆阻器用于模拟生物突触,构建了一个局部有源忆阻突触耦合HR神经元网络。理论分析和数值仿真表明,在局部有源忆阻突触的影响下它能够产生多种放电模式和复杂的混沌行为。最后,实现了该局部有源忆阻突触耦合神经网络的模拟等效电路,并由功率模拟(PSIM)电路仿真验证了数值仿真的正确性。     

惠普忆阻电路的线性叠加分析

基于惠普(HP)忆阻器的元件特性,该文分析了惠普忆阻器的数学关系式,惠普忆阻元件的内部状态变量与忆阻阻值之间存在增量线性关系,在外加电压下惠普忆阻器阻值的变化可叠加,得出了惠普忆阻电路具有线性叠加性的结论。通过PSpice电路仿真验证上述结论的有效性和正确性,为叠加定理在含惠普忆阻器及线性元件的线性电路中的使用提供了理论分析支撑。     

基于忆阻桥效应的光纤式双光路结冰探测方法

近年来,随着防冰、除冰需求的增加,结冰探测技术受到了广泛关注,但传统的结冰传感器量程受限,且后续信号处理电路部分体积较大,难以满足应用需求.基于双光路差动测量的方法,提出一种正方形光纤束探测头分布模式和具有放大效应的忆阻桥网络结构,该网络结构通过对光电探测器的输出光电流信号进行放大,并以网络中感知忆阻器的端电压作为传感输出,从而实现冰层厚度的测量.试验仿真结果表明,该方法探测头端面的安装面积较常用圆形端面光纤束可减小约12.6%,且能够有效消除光路扰动和扩大结冰厚度的测量范围,结冰厚度的测量范围可达到38mm.     

基于Chua电路的一种新型忆阻电路的混沌动力学分析

基于Chua混沌电路和三次光滑忆阻器模型,提出了一种新型忆阻混沌电路.该电路由2个电感、 2个电容、1个忆阻器和1个电阻组成.利用分岔图、Lyapunov指数、相图、Poincaré截面图和Simulink仿真对电路进行分析表明,该电路具有混沌特性.该研究结果可为混沌动力学的研究和混沌保密通信的应用提供理论参考.