Complex behavior of COVID-19’s mathematical model

Wang, Zhen; Jamal, Sajjad Shaukat; Yang, Baonan; Pham, Viet–Thanh

doi:10.1140/epjs/s11734-021-00309-4

Cited by 5 publications

(4 citation statements)

References 23 publications

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“…Another important approach of time series analysis is the Bayesian spectral estimation method [37]. By contrast, in other studies, researchers interpreted the temporal variations of the COVID-19 pandemic using the SEIR model [38,39], which is a wellknown nonlinear dynamical system for epidemics of infectious diseases [40]. However, the…”

Section: Plos Onementioning

confidence: 99%

Time series analysis of daily reported number of new positive cases of COVID-19 in Japan from January 2020 to February 2023

Sumi

2023

PLoS ONE

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This study investigated temporal variations of the COVID-19 pandemic in Japan using a time series analysis incorporating maximum entropy method (MEM) spectral analysis, which produces power spectral densities (PSDs). This method was applied to daily data of COVID-19 cases in Japan from January 2020 to February 2023. The analyses confirmed that the PSDs for data in both the pre- and post-Tokyo Olympics periods show exponential characteristics, which are universally observed in PSDs for time series generated from nonlinear dynamical systems, including the so-called susceptible/exposed/infectious/recovered (SEIR) model, well-established as a mathematical model of temporal variations of infectious disease outbreaks. The magnitude of the gradient of exponential PSD for the pre-Olympics period was smaller than that of the post-Olympics period, because of the relatively high complex variations of the data in the pre-Olympics period caused by a deterministic, nonlinear dynamical system and/or undeterministic noise. A 3-dimensional spectral array obtained by segment time series analysis indicates that temporal changes in the periodic structures of the COVID-19 data are already observable before the commencement of the Tokyo Olympics and immediately after the introduction of mass and workplace vaccination programs. Additionally, the possibility of applying theoretical studies for measles control programs to COVID-19 is discussed.

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Section: Plos Onementioning

confidence: 99%

Time series analysis of daily reported number of new positive cases of COVID-19 in Japan from January 2020 to February 2023

Sumi

2023

PLoS ONE

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“…A compilation of a group of papers dealing with different aspects of Covid-19 dynamics is presented in this Special Issue. Wang et al [ 13 ] provide the contribution introducing complex behavior of a Covid-19’s mathematical model. Their results show that for a certain set of parameters can be related to chaos.…”

Section: Covid-19 Modelingmentioning

confidence: 99%

Complex bio rhythms

Akgül

Savi

Yıldız

et al. 2022

Eur. Phys. J. Spec. Top.

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Complex biorhythms are characteristic of ubiquitous phenomena appearing in many disciplines of human knowledge. This Special Issue collects articles devoted to different complex biorhythms phenomena such as cardiac dynamics, Covid-19 dynamics, dynamics of neural networks, cell dynamics, and a few articles devoted to general methods. It furnishes a rich overview of the field and can stimulate and inspire further researches.

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“…The findings revealed that the dynamic behavior of chaotic circuits incorporating memristors is intricately linked to the system parameters and the initial conditions [10]. At the same time, Wang identified various complex chaotic phenomena within these systems, such as extreme multistability, transient chaos, state transitions, and chaotic explosions [11][12][13]. In addition, researchers have also carried out a lot of work on the application of memristors in the double T-shaped oscillator, the Venn oscillator, and the classical Lorenz and Jerk chaotic systems, and they have obtained memristor chaotic attractors with different states [14][15][16].…”

Section: Introductionmentioning

confidence: 97%

Dynamic Analysis and Sliding Mode Synchronization Control of Chaotic Systems with Conditional Symmetric Fractional-Order Memristors

Tian,

Zhao,

Liu

et al. 2024

Fractal Fract

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In this paper, the characteristics of absolute value memristors are verified through the circuit implementation and construction of a chaotic system with a conditional symmetric fractional-order memristor. The dynamic behavior of fractional-order memristor systems is explored using fractional-order calculus theory and the Adomian Decomposition Method (ADM). Concurrently, the investigation probes into the existence of coexisting symmetric attractors, multiple coexisting bifurcation diagrams, and Lyapunov exponent spectra (LEs) utilizing system parameters as variables. Additionally, the system demonstrates an intriguing phenomenon known as offset boosting, where the embedding of an offset can adjust the position and size of the system’s attractors. To ensure the practical applicability of these findings, a fractional-order sliding mode synchronization control scheme, inspired by integer-order sliding mode theory, is designed. The rationality and feasibility of this scheme are validated through a theoretical analysis and numerical simulation.

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Complex behavior of COVID-19’s mathematical model

Cited by 5 publications

References 23 publications

Time series analysis of daily reported number of new positive cases of COVID-19 in Japan from January 2020 to February 2023

Time series analysis of daily reported number of new positive cases of COVID-19 in Japan from January 2020 to February 2023

Complex bio rhythms

Dynamic Analysis and Sliding Mode Synchronization Control of Chaotic Systems with Conditional Symmetric Fractional-Order Memristors

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