1 paper published in Automatica

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Our paper on a frequency domain analysis of slow coherency in networked systems [1] has been published in Automatica. Congrats Hancheng!

[1] [doi] H. Min, R. Pates, and E. Mallada, “A Frequency Domain Analysis of Slow Coherency in Networked Systems,” Automatica, vol. 74, pp. 1-13, 2025.
[Bibtex] [Abstract] [Download PDF]

Network coherence generally refers to the emergence of simple aggregated dynamical behaviors, despite heterogeneity in the dynamics of the network’s subsystems. In this paper, we develop a general frequency domain framework to analyze and quantify the level of network coherence that a system exhibits by relating coherence with a low-rank property of the system’s input-output response. More precisely, for a networked system with linear dynamics and coupling, we show that, as the network’s effective algebraic connectivity grows, the system transfer matrix converges to a rank-one transfer matrix representing the coherent behavior. Interestingly, the non-zero eigenvalue of such a rank-one matrix is given by the harmonic mean of individual nodal dynamics, and we refer to it as coherent dynamics. Our analysis unveils the frequency-dependent nature of coherence and a non-trivial interplay between dynamics and network topology. We further show that many networked systems can exhibit similar coherent behavior by establishing a concentration result in a setting with randomly chosen individual nodal dynamics.

@article{mpm2025automatica,
  abstract = {Network coherence generally refers to the emergence of simple aggregated dynamical behaviors, despite heterogeneity in the dynamics of the network's subsystems. In this paper, we develop a general frequency domain framework to analyze and quantify the level of network coherence that a system exhibits by relating coherence with a low-rank property of the system's input-output response. More precisely, for a networked system with linear dynamics and coupling, we show that, as the network's effective algebraic connectivity grows, the system transfer matrix converges to a rank-one transfer matrix representing the coherent behavior. Interestingly, the non-zero eigenvalue of such a rank-one matrix is given by the harmonic mean of individual nodal dynamics, and we refer to it as coherent dynamics. Our analysis unveils the frequency-dependent nature of coherence and a non-trivial interplay between dynamics and network topology. We further show that many networked systems can exhibit similar coherent behavior by establishing a concentration result in a setting with randomly chosen individual nodal dynamics.},
  author = {Min, Hancheng and Pates, Richard and Mallada, Enrique},
  bdsk-url-3 = {https://mallada.ece.jhu.edu/pubs/2025-Automatica-MPM.pdf},
  bdsk-url-4 = {https://doi.org/10.1016/j.automatica.2025.112184},
  doi = {https://doi.org/10.1016/j.automatica.2025.112184},
  grants = {CAREER-1752362, TRIPODS-1934979, CPS-2136324},
  journal = {Automatica},
  month = {2},
  pages = {1-13},
  record = {published, available online Dec 2024, accepted Oct 2024, revised Feb 2024, submitted Feb 2022},
  title = {A Frequency Domain Analysis of Slow Coherency in Networked Systems},
  url = {https://mallada.ece.jhu.edu/pubs/2025-Automatica-MPM.pdf},
  volume = {74},
  year = {2025}
}