外腔反馈半导体激光器在合适的反馈强度下将呈现混沌态,其输出的激光混沌信号可作为物理熵源获取物理随机数序列.着重研究了外腔反馈强度对最后获取的二元码序列的随机性的影响.数值仿真结果表明,随着反馈强度的增加,外腔反馈半导体激...外腔反馈半导体激光器在合适的反馈强度下将呈现混沌态,其输出的激光混沌信号可作为物理熵源获取物理随机数序列.着重研究了外腔反馈强度对最后获取的二元码序列的随机性的影响.数值仿真结果表明,随着反馈强度的增加,外腔反馈半导体激光器输出的混沌信号的延时时间特征峰值呈现先逐渐减小再逐渐增大的过程,而对应的排列熵特征值呈现先增大、后缓慢降低的过程,即存在一个优化的反馈强度可使输出的混沌信号的延时特征得到有效抑制且复杂度高.利用NIST Special Publication 800-22软件对基于不同反馈强度下外腔半导体激光器输出的混沌信号所产生的二元码序列的随机性进行了相关测试,并讨论了反馈强度的大小对测试结果的影响.展开更多
Synchronization behavior of an ensemble of unidirectionally coupled neurons with a constant input is investigated. Chemical synapses are considered for coupling. Each neuron is also considered to be exposed to a self-...Synchronization behavior of an ensemble of unidirectionally coupled neurons with a constant input is investigated. Chemical synapses are considered for coupling. Each neuron is also considered to be exposed to a self-delayed feedback. The synchronization phenomenon is analyzed by the error dynamics of the response trajectories of the system. The effect of various model parameters e.g. coupling strength, feedback gain and time delay, on synchronization is also investigated and a measure of synchrony is computed in each cases. It is shown that the synchronization is not only achieved by increasing the coupling strength, the system also required to have a suitable feedback gain and time delay for synchrony. Robustness of the parameters for synchrony is verified for larger systems.展开更多
文摘外腔反馈半导体激光器在合适的反馈强度下将呈现混沌态,其输出的激光混沌信号可作为物理熵源获取物理随机数序列.着重研究了外腔反馈强度对最后获取的二元码序列的随机性的影响.数值仿真结果表明,随着反馈强度的增加,外腔反馈半导体激光器输出的混沌信号的延时时间特征峰值呈现先逐渐减小再逐渐增大的过程,而对应的排列熵特征值呈现先增大、后缓慢降低的过程,即存在一个优化的反馈强度可使输出的混沌信号的延时特征得到有效抑制且复杂度高.利用NIST Special Publication 800-22软件对基于不同反馈强度下外腔半导体激光器输出的混沌信号所产生的二元码序列的随机性进行了相关测试,并讨论了反馈强度的大小对测试结果的影响.
文摘Synchronization behavior of an ensemble of unidirectionally coupled neurons with a constant input is investigated. Chemical synapses are considered for coupling. Each neuron is also considered to be exposed to a self-delayed feedback. The synchronization phenomenon is analyzed by the error dynamics of the response trajectories of the system. The effect of various model parameters e.g. coupling strength, feedback gain and time delay, on synchronization is also investigated and a measure of synchrony is computed in each cases. It is shown that the synchronization is not only achieved by increasing the coupling strength, the system also required to have a suitable feedback gain and time delay for synchrony. Robustness of the parameters for synchrony is verified for larger systems.
