中立型驱动反应BAM 神经网络的全局渐近同步性

针对一类具有时滞的中立型驱动反应BAM神经网络,提出全局渐近同步性问题.不使用现有文献中传统的李雅普诺夫泛函、矩阵测度和线性矩阵不等式(LMI)等已被广泛应用于研究神经网络全局渐近同步性的方法,而是通过构造2个微分不等式U 1(t)和U 1(t),利用微分不等式方程和不等式技巧解出2个不等式,得到能够确保中立型驱动反应BAM神经网络全局渐近同步的两个新的充分条件.     

“聚龙一号”丝阵实验轴向一维X光辐射功率分布

通过一维条纹相机诊断系统对聚龙一号(JL-Ⅰ)四类单层丝阵负载进行了轴向X光辐射测量。由于瑞利-泰勒不稳定性的影响，大部分负载表现出两端发光比中间滞后、阳极端发光比阴极端滞后、阳极端发光总强度弱于阴极端的现象。通过不同类型丝阵对比，对于20 mm直径的丝阵，JL-Ⅰ驱动器的匹配负载线质量在0.9 mg/cm附近。轴向辐射同步性与辐射功率之间存在相关性。     

基于以太网运动控制总线同步性的研究

通过对以太网特点的分析,了解了其存在的问题;分析以太网周期性通讯的过程,通过对延迟时间的补偿,降低对控制器的要求。     

二维叠栅条纹的傅里叶变换北大核心CSCD

研究了方形孔径平面微透镜阵列和微图形阵列的叠栅条纹的傅里叶原理。方形孔径平面微透镜阵列可视为正交的二维栅格线簇,以一维光栅叠栅条纹的傅里叶变换原理为基础,推导了方形孔径平面微透镜阵列二维叠栅条纹的傅里叶变换解析式,对低频(1,-1)级叠栅条纹进行详细讨论。同时对不同夹角下叠栅条纹的周期和同步性进行重点研究,并采用不同结构参数的二维栅格模板与微图形阵列进行实验,结果表明:实验值和理论值相吻合,研究结果为方形孔径平面微透镜阵列的应用与研究提供了理论基础。     

多层二分耦合网络的同步性研究

多层复杂网络的同步能力分析是目前网络科学研究的热点.首先根据主稳定方程(MSF)给出多层二分耦合网络的超拉普拉斯矩阵,并得到反映其同步能力的重要指标.其次分析了二分耦合网络在同步域有界和无界的两种情况下层数、二分耦合网络节点数、层间耦合强度和层内耦合强度对同步能力的影响.最后通过数值模拟和理论实践提出控制层数、二分耦合网络节点数、层间耦合强度和层内耦合强度等参数的策略,来实现优化多层二分耦合网络的同步能力,为工程技术人员在实际应用中优化其同步能力提供有效的方案.     

空间相机调焦机构同步性精度分析

调焦机构是空间相机获得良好成像质量的重要保障。由于调焦机构焦平面两端的同步性误差不可避免,会对成像质量造成影响,因此对双凸轮和丝杠螺母调焦机构同步性误差进行了分析。介绍了两种调焦机构工作原理;分析了两种调焦机构同步性误差的来源并对其同步性误差进行了计算;对两种调焦机构的同步性进行了测试验证。两种调焦机构采用统计法和蒙特卡罗法计算同步性误差,验证结果与之相符。满足调焦机构同步性误差的最大允许值±20μm,完全满足现阶段使用要求。     

Synchronization of Modified Chua＇s Circuit with x｜x｜ Function

This paper considers the chaos synchronization of the modified Chua＇s circuit with x｜x｜ function. We firstly show that a couple of the modified Chua systems with different parameters and initial conditions can be synchronized using active control when the values of parameters both in drive system and response system are known aforehand.Furthermore, based on Lyapunov stability theory we propose an adaptive active control approach to make the states of two identical Chua systems with unknown constant parameters asymptotically synchronized. Moreover the designed controller is independent of those unknown parameters. Numerical simulations are given to validate the proposed synchronization approach.     

A NEW SYNCHRONIZATION SCHEME USING PERFECT PUNCTURED BINARY SEQUENCE PAIRS IN DS-UWB SYSTEM

Ultra WideBand （UWB） radio is a new wireless technology that transmits extremely short duration radio impulses. In this paper, a new synchronization scheme is proposed in Direct Sequence （DS） UWB system using Perfect Punctured Binary Sequence Pairs （PPBSP） as the preamble. It can acquire both Pseudo- Noise （PN） sequence and frame synchronization at the same time. The properties and the combinatorial admissibility conditions of PPBSP are presented. The simulation results show that PPBSP is good for synchronization by their good cross-correlation properties both under Additive White Gaussian Noise （AWGN） channel and modified Saleh-Valenzuela channel.     

Synchronization Scheme for Uncertain Chaotic Systems via RBF Neural Network

A sliding mode adaptive synchronization controller is presented with a neural network of radial basis function （RBF） for two chaotic systems. The uncertainty of the synchronization error system is approximated by the RBF neural network. The synchronization controller is given based on the output of the RBF neural network. The proposed controller can make the synchronization error convergent to zero in 5s and can overcome disruption of the uncertainty of the system and the exterior disturbance. Finally, an example is given to illustrate the effectiveness of the proposed synchronization control method.