Article
Physics, Multidisciplinary
Huawei Fan, Ya Wang, Xingang Wang
Summary: While topological symmetries are crucial for synchronization patterns in complex networks, it remains challenging to identify these symmetries in large networks. This study proposes an eigenvector-based analysis framework to identify synchronization patterns and investigate the emergence and transition of cluster synchronization states. The method can predict observable cluster synchronization states, critical couplings, and the sequence of these states without prior knowledge of network symmetries. The proposed framework is validated using different models of coupled chaotic oscillators, showing its efficacy and generality in studying synchronization patterns in large, complex networks.
FRONTIERS OF PHYSICS
(2023)
Article
Physics, Multidisciplinary
Yun Zhai, Xuan Wang, Jinghua Xiao, Zhigang Zheng
Summary: This paper studies the stability of the synchronous state in coupled phase oscillators. It is found that numerical integration with a finite time step may induce desynchronization at strong couplings. The desynchronization critical couplings increase and diverge as a power law with decreasing the integral time step. Theoretical analysis supports the local stability of the synchronized state, while the global emergence of synchronized states depends on the initial conditions. Other metastable ordered states such as twisted states can coexist with the synchronous mode but lose stability when the network becomes dense.
Article
Computer Science, Information Systems
Yan Zong, Xuewu Dai, Shang Gao, Pep Canyelles-Pericas, Shuxin Liu
Summary: This article proposes a solution for clock synchronization in wireless blast wave monitoring networks, solving the problem of clock drift and improving synchronization accuracy. Experimental results demonstrate that this method provides an effective clock synchronization solution for blast wave monitoring networks.
IEEE INTERNET OF THINGS JOURNAL
(2022)
Article
Mathematics, Applied
Erik T. K. Mau, Michael Rosenblum, Arkady Pikovsky
Summary: Phase reduction is a general approach for describing coupled oscillatory units by focusing on their phases. This paper presents a general framework for obtaining higher-order coupling terms in terms of the coupling parameter for two-dimensional oscillators with arbitrary coupling terms. The theory is applied to accurately predict Arnold's tongue phenomenon for the van der Pol oscillator using higher-order phase reduction.
Article
Automation & Control Systems
Jiayi Liu, Shuaihao Jiang, Yanbin Qu, Xuewei Zhang, Huihui Song
Summary: This paper discusses the global stability of coupled control systems (CCSs) and their application in microgrids. By using graph theory to construct a Lyapunov function and deriving stability criteria, the global asymptotical stability criterion for microgrids and sliding mode control method are proposed.
JOURNAL OF THE FRANKLIN INSTITUTE-ENGINEERING AND APPLIED MATHEMATICS
(2021)
Article
Physics, Fluids & Plasmas
Mei Zhang, Yuhe Yang, Junzhong Yang
Summary: This work investigates partial synchronization in a ring of locally coupled identical oscillators and presents a systematic method to identify all partially synchronous dynamics on their synchronous manifolds. The correspondence between partially synchronous states and conjugacy classes of subgroups of the dihedral group DN is established. The study reveals a hierarchical structure of partially synchronous states, with upstream states being less synchronous than downstream states along a directed path in the structure.
Article
Automation & Control Systems
Ze Tang, Ju H. Park, Yan Wang, Jianwen Feng
Summary: This article explores adaptive control and exponential synchronization of derivative coupled complex dynamical networks with proportional delay. It presents criteria for achieving exponential synchronization using impulsive control and adaptive pinning control protocols, and provides suitable control gains for adaptive synchronization. Numerical simulations validate the theoretical results, and the concept of impulsive distance is introduced to assist in controller design.
IEEE TRANSACTIONS ON SYSTEMS MAN CYBERNETICS-SYSTEMS
(2021)
Article
Physics, Fluids & Plasmas
Antonio Palacios
Summary: Synchronization among symmetrically coupled homogeneous oscillators is common, but recent studies have shown that stable synchronization in asymmetric networks can only be achieved with heterogeneous oscillators. This paper mathematically proves and numerically confirms that stable synchronization can exist in asymmetrically coupled homogeneous oscillators.
Article
Physics, Multidisciplinary
Fahhad H. Alharbi, Abdelrahman S. Abdelrahman, Abdullah M. Alkathiry, Hussain M. Al-Qahtani
Summary: In this study, the Frimmer-Novotny model for simulating two-level systems by coupled oscillators is extended by incorporating a constant time delay in the coupling. The effects of this delay on system dynamics and two-level modeling are investigated and found to be substantial. The results show that the delay has oscillatory effects on the system dynamics and can govern the energy transfer dynamics and coherence. The delay and the coupling strength both play a critical role in determining the stability of the system.
Article
Neurosciences
Elisabetta Corti, Joaquin Antonio Cornejo Jimenez, Kham M. Niang, John Robertson, Kirsten E. Moselund, Bernd Gotsmann, Adrian M. Ionescu, Siegfried Karg
Summary: A new in-memory computing platform based on coupled VO2 oscillators fabricated in a crossbar configuration on silicon is proposed in this work. The platform shows promising improvements in area density and oscillation frequency, enabling experiments on 4-coupled oscillators. The concept is tested with a VGG13 architecture on the MNIST dataset, achieving performances of 95% in the recognition task.
FRONTIERS IN NEUROSCIENCE
(2021)
Article
Mathematics, Applied
Sabina Adhikari, Juan G. G. Restrepo, Per Sebastian Skardal
Summary: We investigate the influence of structured higher-order interactions on the collective behavior of coupled phase oscillators. Using a combination of hypergraph generative model and dimensionality reduction techniques, we derive a reduced system of differential equations for the order parameters of the system. By studying a hypergraph with hyperedges of sizes 2 and 3, we obtain a set of two coupled nonlinear algebraic equations for the order parameters. The system exhibits bistability and explosive synchronization transitions under strong coupling via triangles, and we validate our predictions with numerical simulations. Our results provide a general framework to study synchronization of phase oscillators in hypergraphs with various characteristics.
Article
Mathematics, Applied
Peter Ashwin, Christian Bick, Camille Poignard
Summary: This paper investigates the phenomenon of dead zones in dynamical systems, exploring conditions under which dead zones can emerge in coupled oscillators and applying these findings to coupled multiscale oscillators. The presence of dead zones in phase interactions functions can lead to interesting dynamical consequences for emergent dynamics.
Article
Engineering, Electrical & Electronic
Juan Nunez, Jose M. Quintana, Maria J. Avedillo, Manuel Jimenez, Aida Todri-Sanial, Elisabetta Corti, Siegfried Karg, Bernabe Linares-Barranco
Summary: The study focuses on the implementation of oscillatory neural networks using VO2-based nano-oscillators, addressing key issues such as oscillator initialization and frequency synchronization.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS
(2021)
Article
Physics, Multidisciplinary
Xiaohuan Tang, Huaping Lu, Can Xu
Summary: The study of an extension of the Kuramoto model with higher-order structure reveals several novel dynamical phenomena and proves the stability of multiple multiclusters. By utilizing the partial dimensionality reduction method proposed by Ott-Antonsen, a rigorous analysis of various multi-cluster states is conducted.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2021)
Article
Neurosciences
Manuel Jimenez, Juan Nunez, Jafar Shamsi, Bernabe Linares-Barranco, Maria J. Avedillo
Summary: Oscillatory neural networks (ONNs) are a promising model for energy-efficient computing, utilizing the synchronization dynamics of coupled oscillators. Previous studies have focused on simulation results, but experimental validation is necessary. This study presents an ONN implemented in a commercial CMOS technology, using a circuit to emulate the VO2 device. The designed circuit demonstrates satisfactory operation as an associative memory.
FRONTIERS IN NEUROSCIENCE
(2023)
Article
Mathematics, Interdisciplinary Applications
Alex Arenas, Antonio Garijo, Sergio Gomez, Jordi Villadelprat
Summary: The dynamics of epidemic compartmental models for infectious diseases show a second-order phase transition as a function of the infectivity parameter, transitioning from the absence of infected individuals to an endemic state. We study this transition using a discrete-time compartmental epidemic model called Microscopic Markov Chain Approach, which has been proven to be useful for forecasting epidemic spreading scenarios. Our analysis reveals the existence of a stable and globally attractive endemic state, which is a consequence of transcritical bifurcation. This mathematical analysis validates the practical applications of the model.
CHAOS SOLITONS & FRACTALS
(2023)
Article
Mathematics, Interdisciplinary Applications
Pier Luigi Sacco, Alex Arenas, Manlio De Domenico
Summary: The governance of the political and economic world order relies on international treaties at various geographical scales. Assessing the stability of this architecture is crucial, considering the potential unilateral defection of countries and treaty breakdowns. Our analysis reveals that small and micro countries pose the highest disruption potential, while political stability depends on overseas territories and emerging economies. Economic stability relies on medium-sized European and African countries. Surprisingly, single global treaties have limited disruptive potential, apart from the WTO. Our findings suggest that the fragility of the world order is closely linked to global inequality and fiscal injustice, highlighting the continued influence of the colonial world order.
Article
Multidisciplinary Sciences
Francisco Bauza Mingueza, Mario Floria, Jesus Gomez-Gardenes, Alex Arenas, Alessio Cardillo
Summary: This passage discusses the impact of dynamic interactions among vertices in complex networked systems on the outcome of dynamical processes. It presents a study on the persistence of interactions based on a descriptor called temporality to quantify and characterize the similarity of time-varying network snapshots. The effects of the resolution at which interactions take place on temporality are also examined.
SCIENTIFIC REPORTS
(2023)
Article
Mathematics, Applied
Jorge P. Rodriguez, Victor M. Eguiluz
Summary: Interactions between different diseases can alter their dynamics, posing uncertainty in modeling empirical data when the symptoms of both infections are indistinguishable. By extending previously proposed models to non-symmetric scenarios, we demonstrate that both cooperative and competitive interactions lead to synchronization of the maximum fraction of infected individuals. Using a model that combines the dynamics of COVID-19 and seasonal influenza, we show that the coupling synchronizes both infections, with a stronger influence on influenza dynamics.
Article
Mathematics, Interdisciplinary Applications
Pier Luigi Sacco, Alex Arenas, Manlio De Domenico
Summary: The leak of documents from Mossack Fonseca revealed a complex offshore business network involving individuals and companies engaging in offshore activities and transactions with multiple tax havens. This network forms an effective global infrastructure for tax evasion, with a strongly connected core consisting of well-known tax havens and major global powers. These findings provide insights into the interconnection between tax evaders in a globalized economy and its potential impact on social dynamics and political polarization.
CHAOS SOLITONS & FRACTALS
(2023)
Article
Biodiversity Conservation
Gian Marco Palamara, Alejandro Rozenfeld, Charles N. de Santana, Jan Klecka, Rodrigo Riera, Victor M. Eguiluz, Carlos J. Melian
Summary: This study examines the impact of fluctuations in landscape connectivity on biodiversity dynamics. The results show that local and regional species richness can increase together in dynamic landscapes, and fluctuations in connectivity can increase the overall number of coexisting species. This clarifies the empirical findings of high biodiversity in both low and high-connected landscapes.
Article
Multidisciplinary Sciences
Francesc Belvis, Alberto Aleta, Alvaro Padilla-Pozo, Juan-M. Pericas, Juan Fernandez-Gracia, Jorge P. Rodriguez, Victor M. Eguiluz, Charles Novaes De Santana, Mireia Julia, Joan Benach
Summary: This research examines the evolution of COVID-19 incidence rates and effective reproduction number R(t), as well as their relationship with spatial autocorrelation patterns in Catalonia, Spain. The study finds that there were five major outbreaks, all preceded by R(t) values greater than 1 in the previous two weeks. There is no clear pattern in the initial focus of each wave. Spatial autocorrelation follows a baseline pattern, but deviations occur in some waves, which can be reproduced through interventions to reduce mobility and virus transmissibility.
SCIENTIFIC REPORTS
(2023)
Article
Public, Environmental & Occupational Health
Benjamin Steinegger, Clara Granell, Giacomo Rapisardi, Sergio Gomez, Joan Matamalas, David Soriano-Panos, Alex Arenas
Summary: This study retrospectively analyzed the initial wave of COVID-19 in Spain to understand the impact of NPIs and their interaction with human behavior. The findings showed that regional measures and individual awareness played a significant role in reducing the disease burden before the nationwide lockdown. Counterfactual scenarios suggested that without the early epidemic response, there would have been more fatalities and hospitalizations.
JMIR PUBLIC HEALTH AND SURVEILLANCE
(2023)
Article
Mathematics, Applied
Alex Arenas, Antonio Garijo, Sergio Gomez, Jordi Villadelprat
Summary: This paper investigates a system of coupled oscillators described by the Kuramoto model, discussing the stability and uniqueness criteria of equilibrium solutions. The analysis provides valuable insights into the dynamics of coupled oscillators in this system.
Article
Mathematics, Interdisciplinary Applications
Jiaying Zhou, Yong Ye, Alex Arenas, Sergio Gomez, Yi Zhao
Summary: This study presents a novel delayed fractional-order SIRS reaction-diffusion model on a network, and investigates the impact of delay, average network degree, and diffusion rate on pattern formation through theoretical analysis and numerical experiments. The research findings provide valuable insights into the dynamics of fractional-order systems in relation to network structure.
CHAOS SOLITONS & FRACTALS
(2023)
Article
Biotechnology & Applied Microbiology
Altynay Kaidarova, Nathan R. Geraldi, Rory P. Wilson, Juergen Kosel, Mark G. Meekan, Victor M. Eguiluz, Muhammad Mustafa Hussain, Atif Shamim, Hanguang Liao, Mani Srivastava, Swapnil Sayan Saha, Michael S. Strano, Xiangliang Zhang, Boon S. Ooi, Mark Holton, Lloyd W. Hopkins, Xiaojia Jin, Xun Gong, Flavio Quintana, Adylkhan Tovasarov, Assel Tasmagambetova, Carlos M. Duarte
Summary: Human societies rely on marine ecosystems, which are still experiencing degradation. This article discusses the adaptation of sensors and wearable technology developed for humans to improve marine monitoring. It highlights the barriers to transitioning this technology from land to sea, updates on sensor developments for ocean observation, and advocates for wider use of wearables on marine organisms. The authors propose that widespread use of wearables could contribute to an 'internet of marine life' and inform strategies for marine conservation and restoration.
NATURE BIOTECHNOLOGY
(2023)
Article
Engineering, Environmental
Mattia Mattei, Rosa M. Pinto, Susana Guix, Albert Bosch, Alex Arenas
Summary: We analyzed SARS-CoV-2 genome copies in Catalonia's wastewater and developed a mathematical model to estimate the number of infections and the temporal relationship between reported and unreported cases. Samples from 16 wastewater treatment plants were used in an epidemiological model, showing a strong correlation between genome copies and reported cases with a delay of 8.8 days. The model estimated a higher infection rate (53%) compared to the reported cases (19%), indicating under-reporting in November and December 2021. The maximum genome copies shed in feces by an infected individual ranged from 1.4 x 108 gc/g to 4.4 x 108 gc/g. This study highlights the potential of using wastewater data as an early indicator for new infections and provides a framework for integrating such data into epidemiological models.
Article
Physics, Fluids & Plasmas
Giulio Burgio, Sergio Gomez, Alex Arenas
Summary: In some systems, the behavior of constituent units can modify direct interactions among them by creating a context. Inspired by this mechanism, we developed a minimal model to study context-dependent spreading. We divide the population into two behavior types and provide a mean-field theory to analyze mixing patterns within groups of any size. By examining an epidemic-spreading model with context-dependent adoption of prophylactic tools, we uncover the impact of changing group organization on epidemic spreading and propose a theoretical foundation to model and analyze higher-order contexts in complex systems.
Article
Physics, Fluids & Plasmas
Annalisa Caligiuri, Victor M. Eguiluz, Leonardo Di Gaetano, Tobias Galla, Lucas Lacasa
Summary: By interpreting a temporal network as a trajectory of a latent graph dynamical system, the concept of dynamical instability and a measure to estimate the network maximum Lyapunov exponent (nMLE) is introduced. Nonlinear time-series analysis algorithmic methods are extended to networks to quantify sensitive dependence on initial conditions and estimate the nMLE directly from a single network trajectory. The method is validated for synthetic generative network models displaying low- and high-dimensional chaos, and potential applications are discussed.
Article
Physics, Multidisciplinary
Lucas Lacasa, Jorge P. Rodriguez, Victor M. Eguiluz
Summary: This study investigates the simulation of temporal networks, which model the evolution of interactions between elements in a complex system over time. It interprets temporal networks as trajectories of collective motion in graph space, following a latent graph dynamical system. The study proposes a way to measure how the network pulsates and collectively fluctuates over time and space, and demonstrates the measurement by constructing stochastic and deterministic graph dynamical systems.
PHYSICAL REVIEW RESEARCH
(2022)
