A5031220186- Nonlinear Dynamics and Pattern Formation
- Complex Network Analysis Techniques
- Gene Regulatory Network Analysis
- Opinion Dynamics and Social Influence
- Neural Networks Stability and Synchronization
- Quantum chaos and dynamical systems
- Neural dynamics and brain function
- Chaos control and synchronization
- Complex Systems and Time Series Analysis
- Microbial Metabolic Engineering and Bioproduction
- Bioinformatics and Genomic Networks
- Slime Mold and Myxomycetes Research
- Mathematical Dynamics and Fractals
- Evolution and Genetic Dynamics
- stochastic dynamics and bifurcation
- Ecosystem dynamics and resilience
- Network Security and Intrusion Detection
- Advanced Thermodynamics and Statistical Mechanics
- Microfluidic and Capillary Electrophoresis Applications
- Theoretical and Computational Physics
- Smart Grid Security and Resilience
- Evolutionary Game Theory and Cooperation
- Power Systems and Technologies
- Power Systems and Renewable Energy
- Particle Dynamics in Fluid Flows
Northwestern University
2016-2025
Physical Sciences (United States)
2015-2020
Lund University
2019
United States Naval Research Laboratory
2016
Clarkson University
2014
Boston University
2013
Pennsylvania State University
2012
Princeton University
2011-2012
University of California, Berkeley
2011
Aalto University
2011
We live in a modern world supported by large, complex networks. Examples range from financial markets to communication and transportation systems. In many realistic situations the flow of physical quantities network, as characterized loads on nodes, is important. show that for such networks where can redistribute among intentional attacks lead cascade overload failures, which turn cause entire or substantial part network collapse. This relevant real-world possess highly heterogeneous...
Small-world and scale-free networks are known to be more easily synchronized than regular lattices, which is usually attributed the smaller network distance between oscillators. Surprisingly, we find that with a homogeneous distribution of connectivity synchronizable heterogeneous ones, even though average larger. We present numerical computations analytical estimates on synchronizability in terms its heterogeneity parameters. Our results suggest some degree homogeneity expected naturally...
Complex networks with heterogeneous distribution of loads may undergo a global cascade overload failures when highly loaded nodes or edges are removed due to attacks failures. Since small attack failure has the potential trigger cascade, fundamental question regards possible strategies defense prevent from propagating through entire network. Here we introduce and investigate costless strategy based on selective further removal edges, right after initial failure. This intentional network...
Many complex networks display strong heterogeneity in the degree (connectivity) distribution. Heterogeneity distribution often reduces average distance between nodes but, paradoxically, may suppress synchronization of oscillators coupled symmetrically with uniform coupling strength. Here we offer a solution to this apparent paradox. Our analysis is partially based on identification diffusive process underlying communication and reveals striking relation condition for linear stability...
Patterns of deliberate human activity and behavior are utmost importance in areas as diverse disease spread, resource allocation, emergency response. Because its widespread availability use, e-mail correspondence provides an attractive proxy for studying activity. Recently, it was reported that the probability density inter-event time $τ$ between consecutively sent e-mails decays asymptotically $τ^{-α}$, with $α\approx 1$. The slower than exponential decay distribution suggests is inherently...
Realistic networks display not only a complex topological structure, but also heterogeneous distribution of weights in the connection strengths. Here we study synchronization weighted and show that synchronizability random with large minimum degree is determined by two leading parameters: mean heterogeneity node's intensity, where intensity node, defined as total strength input connections, natural combination topology weights. Our results provide possibility for control manipulation few parameters.
The domino effect in power failure Sometimes a can be fairly local, but other times, seemingly identical initial cascade to cause massive and costly breakdown the system. Yang et al. built model for North American grid network based on samples of data covering years 2008 2013 (see Perspective by D'Souza). Although observed cascades were widespread, small fraction all components, particularly ones that most cohesive within network, vulnerable cascading failures. Larger associated with...
Abstract The 2021 Nobel Prize in Physics recognized the fundamental role of complex systems natural sciences. In order to celebrate this milestone, editorial presents point view board JPhys Complexity on achievements, challenges, and future prospects field. To distinguish voice opinion each editor, consists a series editor perspectives reflections few selected themes. A comprehensive multi-faceted field complexity science emerges. We hope trust that open discussion will be inspiration for...
We define two words in a language to be connected if they express similar concepts. The network of connections among the many thousands that make up is important not only for study structure and evolution languages, but also cognitive science. this issue quantitatively, by mapping out conceptual English language, with being defined entries Thesaurus dictionary. find presents small-world structure, an amazingly small average shortest path, appears exhibit asymptotic scale-free feature...
Heterogeneity in the degree (connectivity) distribution has been shown to suppress synchronization networks of symmetrically coupled oscillators with uniform coupling strength (unweighted coupling). Here we uncover a condition for enhanced directed weighted coupling. We show that, optimum regime, synchronizability is solely determined by average and does not depend on system size details distribution. In scale-free networks, where may increase heterogeneity, drastically become positively...
We consider maximization of the synchronizability oscillator networks by assigning weights and directions to links a given interaction topology. By extending master stability formalism all possible network structures, we show that, unless some is linked others, maximally synchronizable are necessarily nondiagonalizable can always be obtained imposing unidirectional information flow with normalized input strengths. The results provide insights into hierarchical structures observed in complex...
A common goal in the control of a large network is to minimize number driver nodes or inputs. Yet, physical determination signals and properties resulting trajectories remain widely underexplored. Here we show that (i) numerical fails practice even for linear systems if controllability Gramian ill conditioned, which occurs frequently when existing criteria are satisfied unambiguously, (ii) generally nonlocal phase space, their lengths strongly anti-correlated with success rate inputs, (iii)...
Background: Zipf's discovery that word frequency distributions obey a power law established parallels between biological and physical processes, language, laying the groundwork for complex systems perspective on human communication. More recent research has also identified scaling regularities in dynamics underlying successive occurrences of events, suggesting possibility similar findings language as well. Methodology/Principal Findings: By considering frequent words USENET discussion groups...
Synchronization, in which individual dynamical units keep pace with each other a decentralized fashion, depends both on the and properties of interaction network. Yet, role played by network has resisted comprehensive characterization within prevailing paradigm that interactions facilitating pairwise synchronization also facilitate collective synchronization. Here we challenge this show networks best complete synchronization, least coupling cost, maximum robustness, have arbitrary complexity...
The dynamics of power-grid networks is becoming an increasingly active area research within the physics and network science communities. results from such studies are typically insightful illustrative, but often based on simplifying assumptions that can be either difficult to assess or not fully justified for realistic applications. Here we perform a comprehensive comparative analysis three leading models recently used study synchronization in -- fundamental problem practical significance...
We introduce a stochastic model that describes the quasi-static dynamics of an electric transmission network under perturbations introduced by random load fluctuations, removing system components from service, repair times for failed components, and response to implement optimal corrections line overloads in damaged or stressed network. use linear approximation flow equations apply programming techniques optimize dispatching generators loads order eliminate associated with system. also...
Cluster synchronization is a phenomenon in which network self-organizes into pattern of synchronized sets. It has been shown that diverse patterns stable cluster can be captured by symmetries the network. Here we establish theoretical basis to divide an arbitrary symmetry clusters independently synchronizable sets, stability individual each set decoupled from all other Using this framework, suggest new approach find permanently chimera states capturing two or more clusters---at least one and...
Spontaneous synchronization has long served as a paradigm for behavioral uniformity that can emerge from interactions in complex systems. When the interacting entities are identical and their coupling patterns also identical, complete of entire network is state inheriting system symmetry. As other systems subject to symmetry breaking, such symmetric states not always stable. Here we report on discovery converse breaking--the scenario which stable identically-coupled oscillators but becomes...