嘈杂小世界网络中的随机共振现象

Stochastic resonance in a noisy small-world system

以双稳态振荡器耦合而成的具有小世界拓扑结构的网络为研究对象,重点研究了该体系在周期弱信号和乘性高斯白噪声的共同作用下,振荡器之间的耦合强度与网络拓扑结构的无序度对于网络动力学行为的影响.结果显示噪声可以诱导产生随机共振现象,在适中的耦合强度下增加体系拓扑的无序度可以使整个体系的随机共振现象得到加强.另外,研究表明体系中存在着一组最优的耦合强度和拓扑无序度,在它们的协同作用下体系能够最有效地检测到外界的弱信号.

A system composed of coupled bistable oscillators with small-world topological structure is adopted as the object of research in this article under the co-presence of a periodic signal and multiplicative Gaussian white noise, and particular attention is paid to the cooperation of the coupling and the randomness of the network topological structure on the dynamical behaviors of the system. Noise-induced stochastic resonance is observed. Moreover, stochastic resonance can be enhanced by increasing the randomness of the network topology at an intermediate coupling. As a foremost result, it is found that there exists an optimal set of coupling strength and topological randomness under which the system can detect the external weak signal most effectively.