Determination of supercapacitor parameters based on fractional differential equations

In this paper, we estimate the parameter values of a fractional-order model of supercapacitors involving fractional derivatives of Liouville-Caputo, Caputo-Fabrizio, and Atangana-Baleanu and fractional conformable derivative in the Liouville-Caputo sense. We present the exact solution of the considered model using the properties of the Laplace transform operator together with the convolution theorem. They developed numerical simulations using each one of the fractional derivatives; the results were compared graphically with experimental data obtained from different supercapacitors using standard laboratory equipment. The nonlocal parameters involved in the equivalent electrical circuit for the supercapacitor model are recalculated for each fractional derivative using a particle swarm optimization algorithm for generating optimal solutions.     

Multiplicative cases from additive cases: Extension of Kolmogorov–Feller equation to parametric Poisson white noise processes

In this paper the response of nonlinear systems driven by parametric Poissonian white noise is examined.As is well known, the response sample function or the response statistics of a system driven by external white noise processes is completely defined. Starting from the system driven by external white noise processes, when an invertible nonlinear transformation is applied, the transformed system in the new state variable is driven by a parametric type excitation. So this latter artificial system may be used as a tool to find out the proper solution to solve systems driven by parametric white noises. In fact, solving this new system, being the nonlinear transformation invertible, we must pass from the solution of the artificial system (driven by parametric noise) to that of the original one (driven by external noise, that is known). Moreover, introducing this invertible nonlinear transformation into the Itô’s rule for the original system driven by external input, one can derive the Itô’s rule for systems driven by a parametric type excitation, directly. In this latter case one can see how natural is the presence of the Wong–Zakai correction term or the presence of the hierarchy of correction terms in the case of normal and Poissonian white noise, respectively. Direct transformation on the Fokker–Planck and on the Kolmogorov–Feller equation for the case of parametric input are found.     

Design of linear phase FIR filters using fractional derivative constraints

In this paper, the designs of linear phase FIR filters using fractional derivative constraints are investigated. First, the definition of fractional derivative is reviewed briefly. Then, the linear phase FIR filters are designed by minimizing integral squares error under the constraint that the ideal response and actual response have several same fractional derivatives at the prescribed frequency point. Next, the fractional maximally flat FIR filters are designed by letting the number of fractional derivative constraints be equal to the number of filter coefficients. Finally, numerical examples are demonstrated to show that the proposed method has larger design flexibility than the conventional integer derivative constrained methods.     

肠道胶囊式微机器人轴向磁拉力特性

提出一种以径向磁化的瓦状多磁极组成的圆筒式永磁体为外驱动器，以嵌入机器人本体内与外驱动器同磁极结构的永磁体为内驱动器的非接触式驱动控制方案。通过外驱动器的旋转产生旋转磁场，借助于磁机耦合作用，驱动机器人旋转并在其外螺纹表面形成的流体动压力作用下产生轴向推力，进而实现胶囊式机器人在肠道内旋进。基于等效磁荷理论，采用磁荷积分法建立了驱动器的轴向磁拉力模型，对驱动器磁极结构参数与磁拉力的关系特性以及磁拉力与机器人游动关系特性进行了理论与试验研究。     

蓄意流量攻击下基于确定网络演算的互联电网自适应负荷频率控制策略

蓄意流量攻击通过抢占有限的网络带宽降低正常数据流的时效性。对于网络化负荷频率控制(load frequency control, LFC),流量攻击将造成稳定裕度下降、频率偏差幅度上升甚至越限事故。现有控制方案一般采用单一且固定的控制器保证最大攻击强度下的渐进稳定性,存在设计约束多、保守性大的缺点。因此提出了一种跟随攻击强度自适应调整控制器增益的LFC策略。首先,基于确定性网络演算,得到了无攻击场景下数据流传输延时上边界,并预设了一系列表征不同攻击强度的传输延时范围。其次,通过构造Lyapunov泛函,推导了针对每个攻击强度的控制器设计准则。最后,基于切换控制理论,确定了所提自适应方案所能容忍的最大攻击强度变化频率。仿真表明,与现有控制方案相比,所提方法的频率偏差幅度可下降12.60%,区域控制误差的绝对值误差积分可下降10.85%。     

基于双子代数理论的网络建模与分析

本文研究了双子代数尤其是极大代数理论在计算机网络建模与性能分析中的应用.采用极大代数分析了令牌桶的输入输出特性,得到了(b,ρ)令牌桶在极大代数下的状态空间方程组与传输矩阵;提出了基于极大代数的网络演算,定义了极大到达曲线与极大服务曲线,利用这两个概念得出了极大代数下有关延迟以及输出流突发性的定理.最后采用基于极大代数...     

泛函建立方法的研究──变积方法

在变分学中，存在两类互道的问题，一类是将泛函的驻（极）值问题化为微分方程的边（初）值问题（正问题），一类是将微分方程的边（初）值问题化为泛函的驻（极）值问题（逆问题）．本文研究变分学中的逆问题．首先建立了变分的逆运算—变积的概念，然后应用变积运算顺利地将数理方法中的三类典型方程的边（初）值问题化为泛函的驻（极）值问题．     

控制变量受约束的最优控制问题的求解与计算

庞氏最小原则P.M.P.(Pontryagins Minimum Principle)的发现,尽管揭示了最优控制u的一个重要性质,却没有对实际中能够遇到的各种情形,提供寻找u的具体方法。本文通过初等变换方法,将有界控制闭域化为元界开域,于是控制变量受约束的最优控制问题 O.C.P.B.C.(Optimal ControlProblem with Bounded Control)可转化为无约束问题,通过变分法来求解,从而克服了古典变分法的局限性,同时,对求解非线性两点边值问题的多重射击法(Multiple Shooting Method)作了改进,使之适合于计算带内点条件的两点边值问题,提高了O.C.P.B.C.数值计算的效率,最后给出了一个数值例子。     

微机保护算法分析

本文介绍了微机保护中常用的三种算法，分析了它们的原理和特点，指出了每一种算法的适用范围。     

微分关系在画内力图中的应用

现有的材料力学教科书中 ,对轴力图和扭矩图的画法只介绍了截面法 ,本文推广了微分关系画轴力图和扭矩图的方法和步骤 ,为此 ,材料力学中内力图的画法完全都可以用微分关系来完成 .