Are feedback loops destructive to synchronization?

, Article EPL ; Volume 111, Issue 4 , 2015 ; 02955075 (ISSN) Sheshbolouki, A ; Zarei, M ; Sarbazi Azad, H ; Sharif University of Technology

Institute of Physics Publishing 2015

Abstract

We study the effects of directionality on synchronization of dynamical networks. Performing the linear stability analysis and the numerical simulation of the Kuramoto model in directed networks, we show that balancing in- and out-degrees of all nodes enhances the synchronization of sparse networks, especially in networks with high clustering coefficient and homogeneous degree distribution. Furthermore, by omitting all the feedback loops, we show that while hierarchical directed acyclic graphs are structurally highly synchronizable, their global synchronization is too sensitive to the choice of natural frequencies and is strongly affected by noise

The role of leadership in the synchronization of directed complex networks

, Article Journal of Statistical Mechanics: Theory and Experiment ; Volume 2015, Issue 10 , 2015 ; 17425468 (ISSN) Sheshbolouki, A ; Zarei, M ; Sarbazi Azad, H ; Sharif University of Technology

Institute of Physics Publishing 2015

Abstract

Synchronization is a phenomenon that occurs in systems of interacting units, and is widespread in nature, society and technology. Recent studies have enlightened us regarding the interplay between synchronization dynamics and interaction structure. However, most of these studies neglect that real-world networks may actually be directed and disconnected. Here, we study the synchronization of directed networks with multiple leaders using the Kuramoto model. We found that in networks with high driving strength, the steady-state frequency of each node is determined by the linear combination of leaders natural frequencies, with structural coe?cients that can be calculated using the eigenvectors...

Structure and Dynamics of Directed Small World Networks

, M.Sc. Thesis Sharif University of Technology Sheshbolouki, Aida (Author) ; Sarbazi Azad, Hamid (Supervisor) ; Zarei, Mina (Co-Advisor)

Abstract

It has been shown that there is a relationship between the topological and spectral properties of a graph and its dynamics. However, most of the studies have not considered the direction of the links, even though most of the real networks are directed. In this thesis, we study the intrinsic relationship between the graphs’ structures, the spectral characteristics of their associated matrices, and the synchronization implications for different directed random graphs by changing their link directionality. To this end we make use of Kuramoto model for modeling the synchronization dynamics of the network. We show that, in contrast to the results of studies which suggest the λ2/λN as a measure of...

A simulated countercurrent moving bed reactor for oxidation of CO at low concentration over Pt/Al2O3

, Article Studies in Surface Science and Catalysis ; Volume 159 , 2006 , Pages 805-808 ; 01672991 (ISSN) Na-Ranong, D ; Saito, Y ; Yotsumoto, T ; Kazemeini, M ; Aida, T ; Sharif University of Technology

Elsevier Inc 2006