Symmetries, Clusters, and Synchronization Patterns in Complex Networks Thomas E. Murphy Dept. of Electrical & Computer Engineering (ECE) Institute for Research in Electronics & Applied Physics (IREAP) University of Maryland Laboratory for Telecommunication Sciences Lecture Thursday January 23, 2014
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Symmetries, Clusters, and Synchronization Patterns in Complex Networks
Symmetries, Clusters, and Synchronization Patterns in Complex Networks. Thomas E. Murphy Dept. of Electrical & Computer Engineering (ECE) Institute for Research in Electronics & Applied Physics (IREAP) University of Maryland. Laboratory for Telecommunication Sciences Lecture - PowerPoint PPT Presentation
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Symmetries, Clusters, and Synchronization Patterns in
Complex NetworksThomas E. Murphy
Dept. of Electrical & Computer Engineering (ECE)Institute for Research in Electronics & Applied Physics (IREAP)
University of Maryland
Laboratory for Telecommunication Sciences LectureThursday January 23, 2014
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Sponsors
• Office of Naval Research: UMD/DUKE MURI: Exploiting Nonlinear Dynamics for
Novel Sensor Networks DURIP (2009)
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• Lou Pecora (Naval Research Laboratory)
• Prof. Francesco Sorrentino (UNM)
• Prof. Rajarshi Roy (UMD)• Aaron Hagerstrom
(Graduate Research Assistant, Physics)
Contributors and Co-Authors
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• Synchronization of Dynamical Systems• Describing Networks
a• Red and blue clusters are inter-dependent• (sub-group decomposition)
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Transverse Lyapunov Exponent(linearizing about cluster synchrony)
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• N= 25 nodes (oscillators)• 10,000 realizations of each type• Calculate # of symmetries, clusters
Symmetries and Clusters in Random Networks
Random Scale-free Tree Scale-free γ
A.-L. Barabasi and R. Albert, “Emergence of scaling in random networks," Science 286, 509-512 (1999).
K-I Goh, B Kahng, and D Kim, “Universal behavior of load distribution in scale-free networks,“ Phys. Rev. Lett. 87, 278701 (2001).
ndelete= 20
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Symmetries, clusters and subgroup decompositions seem to be universal across many network models
Symmetry Statistics
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Power Network of Nepal
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• 4096 symmetries
• 132 Nodes• 20 clusters• 90 trivial
clusters• 10 subgroups
Mesa Del Sol Electrical Network
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Symmetries & Clusters in Larger Networks
MacArthur et al., “On automorphism groups of networks," Discrete Appl. Math. 156, 3525 (2008).
Number of Symmetries
> 88% of nodes are in clusters in all above networks
Number of Edges
Number of Nodes
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• Synchronization is a widespread in both natural and engineered systems
• Many systems exhibit patterns or clusters of synchrony
• Synchronization patterns are intimately connected to the hidden symmetries of the network
Summary
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• http://arxiv.org/abs/1309.6605 (this work)• B. Ravoori, A. B. Cohen, J. Sun, A. E. Motter, TEM, and R. Roy,
“Robustness of Optimal Synchronization in Real Networks”Physical Review Letters 107, 034102 (2011)
• A. B. Cohen, B. Ravoori, F. Sorrentino, TEM, E. Ott and R. Roy, “Dynamic synchronization of a time-evolving optical network of chaotic oscillators” Chaos 20, 043142 (2010)
• TEM, A. B. Cohen, B. Ravoori, K. R. B. Schmitt, A. V. Setty, F. Sorrentino, C. R. S. Williams, E. Ott and R. Roy, “Chaotic Dynamics and Synchronization of Delayed-Feedback Nonlinear Oscillators” Philosophical Transactions of the Royal Society A 368, 343-366 (2010)
• B. Ravoori, A. B. Cohen, A. V. Setty, F. Sorrentino, TEM, E. Ott and R. Roy, “Adaptive synchronization of coupled chaotic oscillators” Physical Review E 80, 056205 (2009)
• A. B. Cohen, B. Ravoori, TEM and R. Roy, “Using synchronization for prediction of high dimensional chaotic dynamics” Physical Review Letters 101(15), 154102 (2008)