Article Contents
Article Contents

# Outer synchronization of delayed coupled systems on networks without strong connectedness: A hierarchical method

• * Corresponding author: Wenxue Li
• We consider the outer synchronization between drive-response systems on networks with time-varying delays, where we focus on the case when the underlying networks are not strongly connected. A hierarchical method is proposed to characterize large-scale networks without strong connectedness. The hierarchical algorithm can be implemented by some programs to overcome the difficulty resulting from the scale of networks. This method allows us to obtain two different kinds of sufficient outer synchronization criteria without the assumption of being strongly connected, by combining the theory of asymptotically autonomous systems with Lyapunov method and Kirchhoff's Matrix Tree Theorem in graph theory. The theory improves some existing results obtained by graph theory. As illustrations, the theoretic results are applied to delayed coupled oscillators and a numerical example is also given.

Mathematics Subject Classification: Primary: 34A34; Secondary: 68W01, 34C15.

 Citation:

• Figure 1.  Example of two networks with identical coupling structure. The solid lines represent the deterministic coupling among the nodes within a network, while dashed ones represent the coupling between the drive network and response network.

Figure 2.  A general digraph $\mathcal{G}$ with 67 vertices and the corresponding condensed digraph $\mathcal{H}$

Figure 3.  Digraph $(\mathcal{G},B)$ with 20 vertices and a not strongly connected network.

Figure 4.  The pathes of the derive system (7) with initial value $(x_{1+5i} = 50,\tilde{x}_{1+5i} = -50,x_{2+5i} = 60,$$\tilde{x}_{2+5i} = -60,x_{3+5i} = 0,\tilde{x}_{3+5i} = 0,x_{4+5i} = 60,$$\tilde{x}_{4+5i} = -60,x_{5+5i} = 70,\tilde{x}_{5+5i} = -70,i = 0,1,2,3)$.

Figure 5.  The pathes of response system (8) with initial value $(y_{1+5i} = 0,\tilde{y}_{1+5i} = -170,y_{2+5i} = -70,$$\tilde{y}_{2+5i} = 30,y_{3+5i} = 0,\tilde{y}_{3+5i} = 0,y_{4+5i} = -30,$$\tilde{y}_{4+5i} = 30,y_{5+5i} = 40,\tilde{y}_{5+5i} = 20,i = 0,1,2,3)$.

Figure 6.  The pathes of the synchronization error system with initial value $(e_{1+5i} = -50,\tilde{e}_{1+5i} = -120,e_{2+5i} = -130,$$\tilde{e}_{2+5i} = 90,e_{3+5i} = 0,\tilde{e}_{3+5i} = 0,e_{4+5i} = -100,$$e_{5+5i} = -40,\tilde{e}_{5+5i} = 110,i = 0,1,2,3)$.

Figure 7.  Digraph $(\mathcal{G},A)$ and its strongly connected components $\mathfrak{H}_{i}$ are shown in (a). The corresponding condensed digraph $\mathcal{H}$ is shown in (b).

 $\mathrm{Forms}$ $k\in\{1,\ldots,5\}$ $k\in\{6,\ldots,10\}$ $k\in\{11,\ldots,15\}$ $k\in\{16,\ldots,20\}$ $\tau_{k}(t)$ $0.5(\sin(t)+1)$ $0.5(\cos(t)+1)$ $0.4(\sin(t)+1)$ $0.4(\cos(t)+1)$ $N_{h}(x_{h})$ $\sin(x_{h})$ $\cos(x_{h})$ $0.5\sin(2x_{h})$ $0.5\cos(2x_{h})$
 $\mathrm{Parameters}$ $k\in\{1,\ldots,5\}$ $k\in\{6,\ldots,10\}$ $k\in\{11,\ldots,15\}$ $k\in\{16,\ldots,20\}$ $\epsilon_{k}$ $1.8$ $1.9$ $2.0$ $2.1$ $\varepsilon_{k}$ $0.05$ $0.1$ $0.15$ $0.2$
•  H. Chen  and  J. Sun , Stability analysis for coupled systems with time delay on networks, Physica A, 391 (2012) , 528-534.  doi: 10.1016/j.physa.2011.08.037. C. Cheng , T. Liao  and  C. Wang , Exponential synchronization of a class of chaotic neural networks, Chaos Soliton. Fract., 24 (2005) , 197-206.  doi: 10.1016/S0960-0779(04)00566-1. C. Cheng , Robust synchronization of uncertain unified chaotic systems subject to noise and its application to secure communication, Appl. Math. Comput., 219 (2012) , 2698-2712.  doi: 10.1016/j.amc.2012.08.101. Y. Dong and J. Chen, Finite-time outer synchronization between two complex dynamical networks with on-off coupling, Int. J. Model Phys. C, 26 (2015), 1550095, 13 pp. P. Du  and  M. Y. Li , Impact of network connectivity on the synchronization and global dynamics of coupled systems of differential equations, Physica D, 286/287 (2014) , 32-42.  doi: 10.1016/j.physd.2014.07.008. W. Du, J. Zhang, X. An, S. Qin and J. Yu, Outer synchronization between two coupled complex networks and its application in public traffic supernetwork, Discrete Dyn. Nat. Soc. , 2016 (2016), Art. ID 8920764, 8 pp. R. Ghosh  and  K. Lerman , Rethinking Centrality: The role of dynamical processes in social network analysis, Discrete cont. Dyn-B, 19 (2014) , 1355-1372.  doi: 10.3934/dcdsb.2014.19.1355. Y. Guo , S. Liu  and  X. Ding , The existence of periodic solutions for coupled Rayleigh system, Neurocomputing, 191 (2016) , 398-408.  doi: 10.1016/j.neucom.2016.01.039. H. Guo , M. Y. Li  and  Z. Shuai , A graph-theoretic approach to the method of global Lyapunov functions, Proc. Amer. Math. Soc., 136 (2008) , 2793-2802.  doi: 10.1090/S0002-9939-08-09341-6. H. Guo , M. Y. Li  and  Z. Shuai , Global dynamics of a general class of multistage models for infectious diseases, SIAM J. Appl. Math., 72 (2012) , 261-279.  doi: 10.1137/110827028. J. K. Hale and S. M. Verduyn Lunel, Introduction to Functional Differential Equations, Applied Mathematical Sciences, 99. Springer-Verlag, New York, 1993. Y. Kao  and  C. Wang , Global stability analysis for stochastic coupled reaction-diffusion systems on networks, Nonlinear Anal. RWA., 14 (2013) , 1457-1465.  doi: 10.1016/j.nonrwa.2012.10.008. R. Leander , S. Lenhart  and  V. Protopopescu , Controlling synchrony in a network of Kuramoto oscillators with time-varying coupling, Physica D, 301/302 (2015) , 36-47.  doi: 10.1016/j.physd.2015.03.003. T. Li , B. Rao  and  Y. Wei , Generalized exact boundary synchronization for a coupled system of wave equation, Discrete cont. Dyn-A, 34 (2014) , 2893-2905. W. Li , S. Liu  and  D. Xu , The existence of periodic solutions for coupled pantograph Rayleigh system, Math. Methods Appl. Sci., 39 (2016) , 1667-1679.  doi: 10.1002/mma.3556. C. Li , W. Sun  and  J. Kurths , Synchronization between two coupled complex networks, Phys. Rev. E, 76 (2007) , 046204.  doi: 10.1103/PhysRevE.76.046204. M. Y. Li  and  Z. Shuai , Global-stability problem for coupled systems of differential equations on networks, J. Differ. Equ., 248 (2010) , 1-20.  doi: 10.1016/j.jde.2009.09.003. W. Li , H. Su  and  K. Wang , Global stability analysis for stochastic coupled systems on networks, Automatica, 47 (2011) , 215-220.  doi: 10.1016/j.automatica.2010.10.041. B. Lisena , Average criteria for periodic neural networks with delay, Discrete cont. Dyn-B, 19 (2014) , 761-773.  doi: 10.3934/dcdsb.2014.19.761. X. Liu  and  T. Chen , Boundedness and synchronization of $y$-coupled Lorenz systems with or without controllers, Physica D, 237 (2008) , 630-639.  doi: 10.1016/j.physd.2007.10.006. Y. Lou , W. M. Ni  and  S. Yotsutani , Pattern formation in a cross-diffusion system, Discrete cont. Dyn-A, 35 (2015) , 1589-1607. K. Mischaikow , H. Smith  and  H. Thieme , Asymptotically autonomous semiflows: Chain recurrence and Lyapunov functions, T. Am. Math. Soc., 347 (1995) , 1669-1685.  doi: 10.1090/S0002-9947-1995-1290727-7. K. Modin  and  O. Verdier , Integrability of nonholonomically coupled oscillators, Discrete cont. Dyn-A, 34 (2014) , 1121-1130. H. Shu , D. Fan  and  J. Wei , Global stability of multi-group SEIR epidemic models with distributed delays and nonlinear transmission, Nonlinear Anal. RWA., 13 (2012) , 1581-1592.  doi: 10.1016/j.nonrwa.2011.11.016. S. H. Strogatz , Exploring complex networks, Nature, 140 (2001) , 268-276.  doi: 10.1038/35065725. H. Su, W. Li and K. Wang, Global stability analysis of discrete-time coupled systems on networks and its applications, Chaos, 22 (2012), 033135, 11pp. R. Tarjan , Depth-first search and linear graph algorithms, SIAM J. Comput., 1 (1972) , 146-160.  doi: 10.1137/0201010. H. Thieme , Asymptotically autonomous differential equations in the plane, Rocky Mt. J. Math., 24 (1994) , 351-380. J. P. Tseng , Global asymptotic dynamics of a class of nonlinearly coupled neural networks with delays, Discrete cont. Dyn-A, 33 (2013) , 4693-4729.  doi: 10.3934/dcds.2013.33.4693. G. Wang , J. Cao  and  J. Lu , Outer synchronization between two nonidentical networks with circumstance noise, Physica A, 389 (2010) , 1480-1488.  doi: 10.1016/j.physa.2009.12.014. D. B. West, Introduction to Graph Theory, Prentice Hall, Upper Saddle River, 1996. J. Xu, D. Park and J. Jo, Local complexity predicts global synchronization of hierarchically networked oscillators, Chaos, 27 (2017), 073116, 11pp. C. Zhang , W. Li  and  K. Wang , Graph theory-based approach for stability analysis of stochastic coupled systems with Lévy noise on networks, IEEE Trans. Neural Netw. Learn. Syst., 26 (2015) , 1698-1709.  doi: 10.1109/TNNLS.2014.2352217. L. Zhang , Wave speed analysis of traveling wave fronts in delayed synaptically coupled neuronal networks, Discrete cont. Dyn-A, 34 (2014) , 2405-2450. S. Zheng , S. Wang , G. Dong  and  Q. Bi , Adaptive synchronization of two nonlinearly coupled complex dynamical networks with delayed coupling, Commun. Nonlinear Sci. Numer. Simul., 17 (2012) , 284-291.  doi: 10.1016/j.cnsns.2010.11.029. Q. Zhu  and  J. Cao , pth moment exponential synchronization for stochastic delayed Cohen-Grossberg neural networks with Markovian switching, Nonlinear Dyn., 67 (2012) , 829-845.  doi: 10.1007/s11071-011-0029-z.

Figures(7)

Tables(2)