Chaos, Solitons and Fractals: X最新文献_第6页

WITHDRAWN: A new 4-D hyper chaotic system generated from the 3-D Rösslor chaotic system, dynamical analysis, chaos stabilization via an optimized linear feedback control, it’s fractional order model and chaos synchronization using optimized fractional order sliding mode control 退出：由三维Rössler混沌系统生成的一个新的四维超混沌系统，动力学分析，通过优化的线性反馈控制实现混沌稳定，其分数阶模型和使用优化的分数阶滑模控制的混沌同步

Chaos, Solitons and Fractals: X Pub Date : 2021-09-01 DOI: 10.1016/j.csfx.2021.100063

G. Laarem

引用次数: 1

Experimental detection of Hopf bifurcation in two-dimensional dynamical systems 二维动力系统Hopf分岔的实验检测

Chaos, Solitons and Fractals: X Pub Date : 2021-06-01 DOI: 10.1016/j.csfx.2021.100058

O. Jiménez–Ramírez , E.J. Cruz–Domínguez , M.A. Quiroz–Juárez , J.L. Aragón , R. Vázquez–Medina

{"title":"Experimental detection of Hopf bifurcation in two-dimensional dynamical systems","authors":"O. Jiménez–Ramírez , E.J. Cruz–Domínguez , M.A. Quiroz–Juárez , J.L. Aragón , R. Vázquez–Medina","doi":"10.1016/j.csfx.2021.100058","DOIUrl":"10.1016/j.csfx.2021.100058","url":null,"abstract":"<div><p>In this work, we propose a strategy based on an analog active network to detect Hopf bifurcations in two–dimensional dynamical systems described by ordinary differential equations. With the proposed strategy, two parameters of the nonlinear system are established in the analog active network by using external controllable voltage levels in order to explore the dynamical evolution of the system in a fast, easy, and accessible way, making our approach a powerful tool to detect Hopf bifurcations in a two-dimensional space. To demonstrate the proposed strategy’s potential and functionality, we electronically implement the kinetics of a reaction-diffusion model proposed by Barrio <em>et al.</em> in 1999 [1], called BVAM model. Hopf bifurcations are detected by following the changes in the system, going from stationary to periodic solutions when varying the control parameters. Local linear stability analysis is performed to show the quantitative agreement between analytical and experimental bifurcations. We additionally found that global effects are detected by the experimental approach, which cannot be predicted from a local analysis. The proposed strategy opens the way to use analog active networks to detect bifurcations in dynamical systems experimentally.</p></div>","PeriodicalId":37147,"journal":{"name":"Chaos, Solitons and Fractals: X","volume":"6 ","pages":"Article 100058"},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.csfx.2021.100058","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"106903970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

COVID-19: Is it safe now? Study of asymptomatic infection spread and quantity risk based on SAIR model COVID-19:现在安全吗?基于SAIR模型的无症状感染传播及数量风险研究

Chaos, Solitons and Fractals: X Pub Date : 2021-06-01 DOI: 10.1016/j.csfx.2021.100060

Liu Ying , Tang Xiaoqing

{"title":"COVID-19: Is it safe now? Study of asymptomatic infection spread and quantity risk based on SAIR model","authors":"Liu Ying , Tang Xiaoqing","doi":"10.1016/j.csfx.2021.100060","DOIUrl":"10.1016/j.csfx.2021.100060","url":null,"abstract":"<div><p>Based on the characteristic of the COVID-19 asymptomatic infection, and due to the shortage of traditional mathematical models of transmission dynamics of infectious diseases, we propose a new SAIR model. This SAIR model fully considers the infectious characteristics of asymptomatic cases and the transformation characteristics between the four kinds case. According to the data released by the National Health Commission of P.R.C, the model parameters are calculated, and the transmission process of the COVID-19 is simulated dynamically. It is found that the SAIR model data are in good agreement with the actual data, and the time characteristics of the infection rate are particularly accurate, proving the accuracy and effectiveness of the model. Then, on the basis of the differences between the model data and the real data, the standard deviation of the error is calculated. From the standard deviation, the functional intervals of the confirmed infection rate and the asymptomatic infection rate, the interval of the total number of cases in the model, and the interval of the number of asymptomatic cases in the society are also calculated. The number of asymptomatic cases in society is of important and realistic significance for the assessment of risk and subsequent control measures. Then, according to the dynamic simulation data of the model with changed value of parameters, the remarkable effects of strict quarantines are discussed. Finally, the possible direction of further study is given.</p></div>","PeriodicalId":37147,"journal":{"name":"Chaos, Solitons and Fractals: X","volume":"6 ","pages":"Article 100060"},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.csfx.2021.100060","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49143146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Regime shifts in the COVID-19 case fatality rate dynamics: A Markov-switching autoregressive model analysis COVID-19病死率动态的制度转变:马尔可夫转换自回归模型分析

Chaos, Solitons and Fractals: X Pub Date : 2021-06-01 DOI: 10.1016/j.csfx.2021.100059

Yegnanew A. Shiferaw

{"title":"Regime shifts in the COVID-19 case fatality rate dynamics: A Markov-switching autoregressive model analysis","authors":"Yegnanew A. Shiferaw","doi":"10.1016/j.csfx.2021.100059","DOIUrl":"10.1016/j.csfx.2021.100059","url":null,"abstract":"<div><p>The 2019 novel coronavirus disease (COVID-19) has spread rapidly to many countries around the world from Wuhan, the capital of China’s Hubei province since December 2019. It has now a huge effect on the global economy. As of 13 September 2020, more than 28, 802, 775, and 920, 931 people are infected and dead, respectively. The mortality of COVID-19 infections is increasing as the number of infections increase. Many countries published control measures to contain its spread. Even though there are many drugs and vaccines under trial by pharmaceutical companies and research groups, no specific vaccine or drug has yet been found. Therefore, it is necessary to explain the behaviour of the case fatality rate (CFR) of COVID-19 using the most updated COVID-19 epidemiological data before 13 September 2020. The dynamics in the CFR were analyzed using the Markov-switching autoregressive (MSAR) models. Results showed that the two-regime and three-regime MSAR approach better captured the non-linear dynamics in the CFR time series data for each of the top heavily infected countries including the world. The results also showed that rises in CFRs are more volatile than drops. We believe that this information can be useful for the government to establish appropriate policies in a timely manner.</p></div>","PeriodicalId":37147,"journal":{"name":"Chaos, Solitons and Fractals: X","volume":"6 ","pages":"Article 100059"},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.csfx.2021.100059","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43807483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

A study of ψ-Hilfer fractional differential system with application in financial crisis ψ-Hilfer分数阶微分系统及其在金融危机中的应用研究

Chaos, Solitons and Fractals: X Pub Date : 2021-06-01 DOI: 10.1016/j.csfx.2021.100056

Fatemeh Norouzi , Gaston M. N’Guérékata

引用次数: 10

WITHDRAWN: Existence and uniqueness results for a class of fractional stochastic neutral differential equations 撤下:一类分数阶随机中立型微分方程的存在唯一性结果

Chaos, Solitons and Fractals: X Pub Date : 2020-07-01 DOI: 10.1016/j.csfx.2020.100036

Arzu Ahmadova, N. Mahmudov

引用次数: 2

WITHDRAWN: Application of fractional Gegenbauer functions in variable-order fractional delay-type equations with non-singular kernel derivatives WITHDRAWN：分数Gegenbauer函数在具有非奇异核导数的变阶分数延迟型方程中的应用

Chaos, Solitons and Fractals: X Pub Date : 2020-05-01 DOI: 10.1016/j.csfx.2020.100033

H. Dehestani, Y. Ordokhani, M. Razzaghi

引用次数: 0

WITHDRAWN: On the Closed Loop Nash Equilibrium Strategy for a Class of Sampled Data Stochastic Linear Quadratic Differential Games 撤下:一类抽样数据随机线性二次微分对策的闭环纳什均衡策略

Chaos, Solitons and Fractals: X Pub Date : 2020-04-01 DOI: 10.1016/j.csfx.2020.100028

V. Drăgan, I. Ivanov, I. Popa

引用次数: 0

Synchronization of a class of uncertain chaotic systems utilizing a new finite-time fractional adaptive sliding mode control 一类不确定混沌系统的有限时间分数阶自适应滑模同步控制

Chaos, Solitons and Fractals: X Pub Date : 2020-03-01 DOI: 10.1016/j.csfx.2020.100042

Zahra Rashidnejad, Paknosh Karimaghaee

{"title":"Synchronization of a class of uncertain chaotic systems utilizing a new finite-time fractional adaptive sliding mode control","authors":"Zahra Rashidnejad, Paknosh Karimaghaee","doi":"10.1016/j.csfx.2020.100042","DOIUrl":"10.1016/j.csfx.2020.100042","url":null,"abstract":"<div><p>This paper mainly focuses on the issue of finite-time synchronization of a class of chaotic master and slave systems when they have uncertainties, disturbances, and unknown parameters. It is supposed that Uncertainties and disturbances bounds are unknown. First, using the concept of fractional calculus, a new fractional sliding surface is proposed and its finite-time convergence is also proved. Second, appropriate adaptive laws are introduced to overcome unknown system parameters and these laws correctly estimate the unknown values. With applying the controller, synchronization is achieved within a short time. Also after the synchronization, unstable fluctuations are removed and the controlled system has perfect robustness. The proposed approach is applicable to a wide range of identical or non-identical chaotic master and slave systems. Theoretical analysis and stability examination of the proposed method have been performed utilizing adaptive methods and Lyapunov stability theorem. Thereafter, two practical examples are presented to evaluate the effectiveness and usefulness of the suggested method. Furthermore, this method is compared with methods in recent articles, which shows the superiority of this method.</p></div>","PeriodicalId":37147,"journal":{"name":"Chaos, Solitons and Fractals: X","volume":"5 ","pages":"Article 100042"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.csfx.2020.100042","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"96467723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 19

Dynamics of COVID-19 using inverse problem for coefficient identification in SIR epidemic models 基于逆问题的SIR流行病模型系数辨识的COVID-19动力学

Chaos, Solitons and Fractals: X Pub Date : 2020-03-01 DOI: 10.1016/j.csfx.2020.100041

Tchavdar T. Marinov , Rossitza S. Marinova

引用次数: 36