The stochastic resonance behavior of coupled stochastic resonance(SR)system with time-delay under mass and frequency fluctuations was studied.Firstly,the approximate system model of the time-delay system was obtained ...The stochastic resonance behavior of coupled stochastic resonance(SR)system with time-delay under mass and frequency fluctuations was studied.Firstly,the approximate system model of the time-delay system was obtained by the theory of small time-delay approximation.Then,the random average method and Shapiro-Loginov algorithm were used to calculate the output amplitude ratio of the two subsystems.The simulation analysis shows that increasing the time-delay and the input signal amplitude appropriately can improve the output response of the system.Finally,the system is applied to bearing fault diagnosis and compared with the stochastic resonance system with random mass and random frequency.The experimental results show that the coupled SR system taking into account the actual effect of time-delay and couple can more effectively extract the frequency of the fault signal,and thus realizing the diagnosis of the fault signal,which has important engineering application value.展开更多
This paper investigates synchronization within the new systems, which we denote as Liu system in this paper. New stability criteria for synchronization of linearly coupled Liu systems are attained using the Lyapunov m...This paper investigates synchronization within the new systems, which we denote as Liu system in this paper. New stability criteria for synchronization of linearly coupled Liu systems are attained using the Lyapunov method. Some sufficient conditions for synchronization are concluded through rigorous mathematical theory, which can be further applied to more chaotic systems. Moreover, numerical simulations are given to show the effectiveness of our synchronization criterions.展开更多
In this paper, a new approach to analyze synchronization of linearly coupled map lattices （LCMLs） is presented. A reference vector x（t） is introduced as the projection of the trajectory of the coupled system on th...In this paper, a new approach to analyze synchronization of linearly coupled map lattices （LCMLs） is presented. A reference vector x（t） is introduced as the projection of the trajectory of the coupled system on the synchronization manifold. The stability analysis of the synchronization manifold can be regarded as investigating the difference between the trajectory and the projection. By this method, some criteria are given for both local and global synchronization. These criteria indicate that the left and right eigenvectors corresponding to the eigenvalue ＂0＂ of the coupling matrix play key roles in the stability of synchronization manifold for the coupled system. Moreover, it is revealed that the stability of synchronization manifold for the coupled system is different from the stability for dynamical system in usual sense. That is, the solution of the coupled system does not converge to a certain knowable s（t） satisfying s（tT1） = f（s（t）） but to the reference vector on the synchronization manifold, which in fact is a certain weighted average of each x^i（t） for i=1,……, m, but not a solution s（t） satisfying s（t ＋ 1）=f（s（t））.展开更多
频率分集阵列(frequency diverse array,FDA)雷达具有距离与角度相耦合的波束特性,在与距离相关的干扰抑制或与距离相关的目标定位等一些运用上会受限。为消除这种耦合特性,出于实用性一般采用均匀线性阵列与非线性增长频偏。研究并比...频率分集阵列(frequency diverse array,FDA)雷达具有距离与角度相耦合的波束特性,在与距离相关的干扰抑制或与距离相关的目标定位等一些运用上会受限。为消除这种耦合特性,出于实用性一般采用均匀线性阵列与非线性增长频偏。研究并比较了几种典型的非线性增长频偏形式,对这几种非线性增长频偏形式下的FDA雷达波束特性进行仿真,并分析比较各种频偏形式下FDA雷达关于距离和角度的波束宽度以及副瓣情况。研究表明,需结合实际运用需求和各种频偏形式的特点确定FDA雷达的最优频偏形式,以实现最佳波束运用效用。展开更多
基金Project(61771085)supported by the National Natural Science Foundation of ChinaProject(KJQN 201900601)supported by the Research Project of Chongqing Educational Commission,China。
文摘The stochastic resonance behavior of coupled stochastic resonance(SR)system with time-delay under mass and frequency fluctuations was studied.Firstly,the approximate system model of the time-delay system was obtained by the theory of small time-delay approximation.Then,the random average method and Shapiro-Loginov algorithm were used to calculate the output amplitude ratio of the two subsystems.The simulation analysis shows that increasing the time-delay and the input signal amplitude appropriately can improve the output response of the system.Finally,the system is applied to bearing fault diagnosis and compared with the stochastic resonance system with random mass and random frequency.The experimental results show that the coupled SR system taking into account the actual effect of time-delay and couple can more effectively extract the frequency of the fault signal,and thus realizing the diagnosis of the fault signal,which has important engineering application value.
基金Supported by the National Key Basic Research andDevelopment 973 Programof China (2003CB415200) and State KeyLaboratory of Water Resources and Hydropower Engineering Science(2004C011)
文摘This paper investigates synchronization within the new systems, which we denote as Liu system in this paper. New stability criteria for synchronization of linearly coupled Liu systems are attained using the Lyapunov method. Some sufficient conditions for synchronization are concluded through rigorous mathematical theory, which can be further applied to more chaotic systems. Moreover, numerical simulations are given to show the effectiveness of our synchronization criterions.
基金Project supported by the National Natural Science Foundation of China (No. 60374018, No. 60574044)the Graduate Student Innovation Foundation of Fudan University.
文摘In this paper, a new approach to analyze synchronization of linearly coupled map lattices （LCMLs） is presented. A reference vector x（t） is introduced as the projection of the trajectory of the coupled system on the synchronization manifold. The stability analysis of the synchronization manifold can be regarded as investigating the difference between the trajectory and the projection. By this method, some criteria are given for both local and global synchronization. These criteria indicate that the left and right eigenvectors corresponding to the eigenvalue ＂0＂ of the coupling matrix play key roles in the stability of synchronization manifold for the coupled system. Moreover, it is revealed that the stability of synchronization manifold for the coupled system is different from the stability for dynamical system in usual sense. That is, the solution of the coupled system does not converge to a certain knowable s（t） satisfying s（tT1） = f（s（t）） but to the reference vector on the synchronization manifold, which in fact is a certain weighted average of each x^i（t） for i=1,……, m, but not a solution s（t） satisfying s（t ＋ 1）=f（s（t））.
文摘频率分集阵列(frequency diverse array,FDA)雷达具有距离与角度相耦合的波束特性,在与距离相关的干扰抑制或与距离相关的目标定位等一些运用上会受限。为消除这种耦合特性,出于实用性一般采用均匀线性阵列与非线性增长频偏。研究并比较了几种典型的非线性增长频偏形式,对这几种非线性增长频偏形式下的FDA雷达波束特性进行仿真,并分析比较各种频偏形式下FDA雷达关于距离和角度的波束宽度以及副瓣情况。研究表明,需结合实际运用需求和各种频偏形式的特点确定FDA雷达的最优频偏形式,以实现最佳波束运用效用。
