m值逻辑函数的谱分解式及广义Bent函数的递归构造

本文用概率方法得到ｍ值逻辑函数Ｃｈｒｅｓｔｅｎｓｏｎ循环谱的分解式,据此考察了ｍ值广义Ｂｅｎｔ函数一些新的性质,给出了递归构造ｍ（ｍ≠２ｍｏｄ４）值广义Ｂｅｎｔ函数的一般方法．     

Adaptive synchronization of chaos in permanent magnet synchronous motors based on passivity theory

An adaptive synchronization control method is proposed for chaotic permanent magnet synchronous motors based on the property of a passive system.We prove that the controller makes the synchronization error system between the driving and the response systems not only passive but also asymptotically stable.The simulation results show that the proposed method is effective and robust against uncertainties in the systemic parameters.     

三维气固两相混合层湍流拟序结构的直接数值模拟

本文对三维气固两相混合层湍流拟序结构进行了直接数值模拟。气相流场应用拟谱方法对Ｎ－Ｓ方程组进行直接求解,通过模拟时间模式的混合层流动,分析流场失稳后涡的卷起、配对、合并及撕裂过程,研究三维混合层湍流拟序结构的演变特征;计算颗粒场时,采用Ｌａｇｒａｎｇｉａｎ方法,针对颗粒不同的Ｓｔｏｋｅｓ数,模拟了颗粒场的瞬态分布,并分析流场三维大涡结构对颗粒分布的影响。     

谈Gumbel分布的均值和方差的计算

<正> 一、引言对概率统计中的极值理论有了解的同志都知道,若随机变量的ξ密度函数是e~(-x)e~((-6)~(-x)) (-∞相似文献   

基于微分几何方法的永磁同步电动机的混沌运动的控制

永磁同步电动机(PMSM)在某些参数及工作条件下会出现混沌运动，这将危及电机传动系统的稳定运行，因此如何抑制或消除PMSM中的混沌成为保持其稳定性的关键问题.利用微分几何控制理论，首先从解析上推导出PMSM混沌运动控制律的表达式，然后对控制过程进行仿真.理论分析及数值仿真结果表明：该控制策略不仅行之有效，而且相对其他控制方法具有一定的优越性.研究结果对保证电机传动系统的稳定运行具有较好的参考价值. 关键词： 混沌控制 微分几何 准确线性化 永磁同步电动机     

具有最高代数次数的2n元n维Bent函数的构造

本文给出了代数次数达到最高的一类布尔置换的代数标准形 ;并用m序列的状态转移矩阵和所得置换 ,构造了一类代数次数达到最高的 2n元n维Bent函数 ,用这类函数所构造的S盒具有较高的安全强度 .     

相关免疫逻辑函数的特征矩阵及其计数

本文定义了取值于任意抽象集合的逻辑函数的特征矩阵及其相关免疫性,用概率的方法研究了这类最一般的逻辑函数具有相关免疫性时,其特征矩阵的性质,由此给出了逻辑函数相关免疫的等价判别条件,据此给出了这类相关免疫逻辑函数的一种构造方法并对相关免疫逻辑函数的计数进行了研究,得到了一个一般性的下界.     

Topological probability and connection strength induced activity in complex neural networks

Recent experimental evidence suggests that some brain activities can be assigned to small-world networks. In this work, we investigate how the topological probability p and connection strength C affect the activities of discrete neural networks with small-world (SW) connections. Network elements are described by two-dimensional map neurons (2DMNs) with the values of parameters at which no activity occurs. It is found that when the value of p is smaller or larger, there are no active neurons in the network, no matter what the value of connection strength is; for a given appropriate connection strength, there is an intermediate range of topological probability where the activity of 2DMN network is induced and enhanced. On the other hand, for a given intermediate topological probability level, there exists an optimal value of connection strength such that the frequency of activity reaches its maximum. The possible mechanism behind the action of topological probability and connection strength is addressed based on the bifurcation method. Furthermore, the effects of noise and transmission delay on the activity of neural network are also studied.     

Adaptive robust control of chaotic oscillations in power system with excitation limits

With system parameters falling into a certain area, power system with excitation limits experiences complicated chaotic oscillations which threaten the secure and stable operation of power system. In this paper, to control these unwanted chaotic oscillations, a straightforward adaptive chaos controller based on Lyapunov asymptotical stability theory is designed. Since the presented controller does not need to change the controlled system structure and not to use any information of system except the system state variables, the designed controller is simple and desirable. Simulation results show that the proposed control law is very effective. This work is helpful to maintain the power system＇s security operation.[第一段]     

忆阻Rulkov神经网络同步研究

研究电突触、化学突触以及两者共存对忆阻Rulkov神经模型集体动力学行为的影响。对于两个忆阻Rulkov神经元系统,各种耦合方式都能使系统实现同步。对于不同的耦合强度,神经元呈现不同的放电模式,如方波,三角波,脉冲放电等。当电突触、化学突触同时存在时,系统的同步更依赖于电耦合强度。对全局耦合忆阻Rulkov神经网络同步的研究表明：化学突触单独作用时,同步发生在耦合参数的某个区域范围,当化学耦合强度超过某一阈值时,同步会随着耦合强度的增加而被破坏。电突触单独作用时,系统很快到达同步状态,并且电耦合强度是决定神经元处于静止还是峰放电的关键因素,随着电耦合强度增加,神经元放电频率、振幅增大。当电、化学耦合同时存在时,耦合强度的增加使神经元由静息转变为圆弧放电,并进入同步状态。本文提供了一种通过调整耦合方式和耦合强度,控制神经网络放电模式及其同步的可能方法。