Study On Tracking Synchronization About Irregular And Delay Networks

Synchronization problems of network, as one of the important contents of complexnetwork theory, not only closely connect with our life and production but also show wideapplication prospects in many fields. One of them is the tracking synchronization of network,which has a special practical application value. At present, the research reports about trackingsynchronization of irregular network are still not enough. Therefore, studying on trackingsynchronization about irregular networks is very necessary.In this thesis, the explanation and illustration of some related concepts about network aregiven firstly because these basic concepts are needed to clarify in the process ofunderstanding the network and synchronization of networks.Then, a method adding a controller is put forward to solve the synchronization problemof a scale-free delay network with uncertain parameters. Based on Lyapunov stability theory,the recognition rules of the unknown parameters within chaos systems at nodes of networkand the concrete expression of the controller in the process of tracking synchronizationbetween network and target system are identified. Further, the semiconductor lasersmodulated by current are selected as nodes of a scale-free delay network and to do simulationexperiment. We find that the uncertain parameters in chaos systems at network node areidentified and complete synchronization between network node system and target system isachieved after throwing the controller into the network.Finally, on the basis of above discussion, a very important optical device—signal ringerbium-doped fiber lasers—are chosen as a network node to construct the small world delaynetwork, and to investigate tracking and coupling synchronization problem between the nodesof the small world delay network and target system which is of different structure with signalring erbium-doped fiber laser. Based on the Lyapunov stability theory, we determine thesynchronization principle and the recognition rules of coupling strength in the process ofsynchronization. A sine function model and a Duffing chaotic system are selected as thetarget system, respectively. The simulation result testifies the effectiveness of the trackingsynchronization principle.