Chaos Solitons & Fractals最新文献_第2页

The Analytic Stockwell Transform and its zeros

IF 5.3 1区数学

Chaos Solitons & Fractals Pub Date : 2025-04-24 DOI: 10.1016/j.chaos.2025.116439

Ali Moukadem , Barbara Pascal , Jean-Baptiste Courbot , Nicolas Juillet

{"title":"The Analytic Stockwell Transform and its zeros","authors":"Ali Moukadem , Barbara Pascal , Jean-Baptiste Courbot , Nicolas Juillet","doi":"10.1016/j.chaos.2025.116439","DOIUrl":"10.1016/j.chaos.2025.116439","url":null,"abstract":"<div><div>The Stockwell Transform is a time–frequency representation resulting from an hybridization between the Short-Time Fourier Transform and the Continuous Wavelet Transform. Instead of focusing on energy maxima, an unorthodox line of research has recently shed the light on the zeros of time–frequency transforms, leading to fruitful theoretical developments combining probability theory, complex analysis and signal processing. While the distributions of zeros of the Short-Time Fourier Transform and of the Continuous Wavelet Transform of white noise have been precisely characterized, that of the Stockwell Transform of white noise zeros remains unexplored. To fill this gap, the present work proposes a characterization of the distribution of zeros of the Stockwell Transform of white noise taking advantage of a novel generalized Analytic Stockwell Transform. First of all, an analytic version of the Stockwell Transform is designed. Then, analyticity is leveraged to establish a connection with the hyperbolic Gaussian analytic function, whose zero set is invariant under the isometries of the Poincaré disk. Finally, the theoretical spatial statistics of the zeros of the hyperbolic Gaussian analytic function and the empirical statistics of the zeros the Analytic Stockwell Transform of white noise are compared through intensive Monte Carlo simulations, showing the practical relevance of the established connection. A documented Python toolbox has been made publicly available by the authors.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"197 ","pages":"Article 116439"},"PeriodicalIF":5.3,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143863735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Exploring visibility effects with flux variations under autonomous and human-driven vehicles environment in heterogeneous lattice model

IF 5.3 1区数学

Chaos Solitons & Fractals Pub Date : 2025-04-24 DOI: 10.1016/j.chaos.2025.116454

Poonam Redhu, Shubham Mehta

{"title":"Exploring visibility effects with flux variations under autonomous and human-driven vehicles environment in heterogeneous lattice model","authors":"Poonam Redhu, Shubham Mehta","doi":"10.1016/j.chaos.2025.116454","DOIUrl":"10.1016/j.chaos.2025.116454","url":null,"abstract":"<div><div>This paper presents a novel lattice hydrodynamic model that integrates the flux difference with the visibility effect in a mixed environment of autonomous vehicles (AVs) and human-driven vehicles (HVs). The flux difference term accounts for disparities in vehicle flow between AVs and HVs, as well as a visibility factor to reflect the influence of reduced driver perception on human-driven vehicles. Mainly, the model is designed to capture the unique characteristics of both vehicle types and their interactions, focusing on how limited visibility and varying flux between vehicle groups impact traffic stability and congestion dynamics. Numerical simulation is conducted to evaluate the model’s performance, highlighting the effects of these factors on traffic flow stability, phase transitions and jam formation. We analyze spectral entropy to explore the impact of flux difference, visibility, HV-AV penetration effect and memory information on mixed traffic dynamics from a deeper perspective through simulation. The results indicate that the influence of flux difference and visibility significantly improves traffic stability, particularly under adverse visibility conditions. The enhanced visibility and reaction time parameters of HVs vehicles may complicate in-vehicle interactions as compared to AVs, potentially resulting in delayed responses and increased susceptibility to disturbances. This work provides insights into the role of mixed vehicle environments and offers potential strategies for optimizing traffic flow in future smart transportation systems.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"197 ","pages":"Article 116454"},"PeriodicalIF":5.3,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143870495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Population dynamics of biological synchronous reproduction and the effects of synchronous reproductive cycle on population dynamics

IF 5.3 1区数学

Chaos Solitons & Fractals Pub Date : 2025-04-24 DOI: 10.1016/j.chaos.2025.116438

Jian Gao , Bin Xu , Yaqi Zheng , Chuansheng Shen

{"title":"Population dynamics of biological synchronous reproduction and the effects of synchronous reproductive cycle on population dynamics","authors":"Jian Gao , Bin Xu , Yaqi Zheng , Chuansheng Shen","doi":"10.1016/j.chaos.2025.116438","DOIUrl":"10.1016/j.chaos.2025.116438","url":null,"abstract":"<div><div>Population dynamics and reproductive cycles are fundamental aspects of biological systems, with profound implications for species survival and ecosystem stability. Synchronous reproduction, a phenomenon observed across various taxa, optimizes breeding success and offspring survival but may also introduce complex dynamics under changing environmental conditions. However, there is a scarcity of reports on the impact of synchronous reproduction on population dynamics. This study investigates the influence of synchronous reproductive cycles on population dynamics, with a focus on bifurcation phenomena such as Hopf and period-doubling bifurcations. By employing a series of ordinary differential equation (ODE) models and their discrete difference equation (DDE) counterparts, we analyze the synergistic effects of the reproductive cycle and control parameters on population stability and oscillatory behavior. Numerical simulations demonstrate that synchronous reproduction induces systematic shifts in bifurcation diagrams within the parameter space. Specifically, an increase in reproductive cycle amplifies the displacement of bifurcation curves, revealing that reproductive cycle and control parameters jointly regulate population dynamics. Our results offer actionable guidance for ecosystem management by demonstrating that maintaining or adjusting reproductive synchrony could serve as a leverage point for stabilizing vulnerable populations. Specifically, conservation strategies targeting species with synchronized breeding cycles should prioritize habitat preservation during critical reproductive windows and incorporate climate-driven shifts in reproductive timing into adaptive management frameworks.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"197 ","pages":"Article 116438"},"PeriodicalIF":5.3,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143863736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Vortex droplets and lattice patterns in two-dimensional traps: A photonic spin–orbit-coupling perspective

IF 5.3 1区数学

Chaos Solitons & Fractals Pub Date : 2025-04-24 DOI: 10.1016/j.chaos.2025.116441

S. Sanjay , S. Saravana Veni , Boris A. Malomed

引用次数: 0

Analytic range-Doppler ambiguities for nonautonomous solvable chaos

IF 5.3 1区数学

Chaos Solitons & Fractals Pub Date : 2025-04-23 DOI: 10.1016/j.chaos.2025.116434

Chandra S. Pappu , Aubrey N. Beal , Jonathan N. Blakely , Ned J. Corron

{"title":"Analytic range-Doppler ambiguities for nonautonomous solvable chaos","authors":"Chandra S. Pappu , Aubrey N. Beal , Jonathan N. Blakely , Ned J. Corron","doi":"10.1016/j.chaos.2025.116434","DOIUrl":"10.1016/j.chaos.2025.116434","url":null,"abstract":"<div><div>We present the correlation properties and ambiguity surfaces for a first-order, nonautonomous, chaotic oscillator with a closed-form analytic solution. Unlike most chaotic systems, the solutions of this oscillator take the form of a linear superposition of fixed basis functions weighted by a phase-coded symbol sequence. These solutions enable the analytic investigation of important receiver metrics of systems in a manner that is seldom available when considering chaotic systems. These new, low-order systems exhibit less structure in their basis functions and produce favorable correlation properties with significant mainlobe peak and sidelobe levels below <span><math><mrow><mo>−</mo><mn>20</mn><mspace></mspace><mi>d</mi><mi>B</mi></mrow></math></span> to <span><math><mrow><mo>−</mo><mn>30</mn><mspace></mspace><mi>d</mi><mi>B</mi></mrow></math></span>. Further, averaged ambiguity function results show a ‘thumbtack’ profile with a low-variance, single, localized peak. Consequently, our work validates the ability of these waveforms to resolve multiple-point targets on range-Doppler planes. These desirable characteristics indicate that nonautonomous solvable chaos has significant potential in supporting novel radar, sonar, and remote sensing technologies.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"197 ","pages":"Article 116434"},"PeriodicalIF":5.3,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143863734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Beyond solitons: Deformed solitary solutions to the mathematical model of tumor–immune system interactions

IF 5.3 1区数学

Chaos Solitons & Fractals Pub Date : 2025-04-23 DOI: 10.1016/j.chaos.2025.116419

Z. Navickas , R. Marcinkevicius , I. Telksniene , T. Telksnys , R. Mickevicius , M. Ragulskis

引用次数: 0

Chaotic dynamics and synchronization of multi-region neural network based on locally active memristor

IF 5.3 1区数学

Chaos Solitons & Fractals Pub Date : 2025-04-23 DOI: 10.1016/j.chaos.2025.116437

Ertong Wang , Bin Hu , Zhi-Hong Guan

引用次数: 0

Topological linear and nonlinear gap modes in defected dimer lattice with fourth-order diffraction

IF 5.3 1区数学

Chaos Solitons & Fractals Pub Date : 2025-04-23 DOI: 10.1016/j.chaos.2025.116435

Xiaoyang Wang , Qidong Fu , Changming Huang

引用次数: 0

An SIRS-model considering waning efficacy and periodic re-vaccination 考虑到效力减弱和定期再接种的 SIRS 模型

IF 5.3 1区数学

Chaos Solitons & Fractals Pub Date : 2025-04-19 DOI: 10.1016/j.chaos.2025.116436

Joseph Páez Chávez , Aytül Gökçe , Thomas Götz , Burcu Gürbüz

{"title":"An SIRS-model considering waning efficacy and periodic re-vaccination","authors":"Joseph Páez Chávez , Aytül Gökçe , Thomas Götz , Burcu Gürbüz","doi":"10.1016/j.chaos.2025.116436","DOIUrl":"10.1016/j.chaos.2025.116436","url":null,"abstract":"<div><div>In this paper, we extend the classical SIRS (Susceptible-Infectious-Recovered-Susceptible) model from mathematical epidemiology by incorporating a vaccinated compartment, V, accounting for an imperfect vaccine with waning efficacy over time. The SIRSV-model divides the population into four compartments and introduces periodic re-vaccination for waning immunity. The efficacy of the vaccine is assumed to decay with the time passed since the vaccination. Periodic re-vaccinations are applied to the population. We develop a partial differential equation (PDE) model for the continuous vaccination time and a coupled ordinary differential equation (ODE) system when discretizing the vaccination period. We analyze the equilibria of the ODE model and investigate the linear stability of the disease-free equilibrium (DFE). Furthermore, we explore an optimization framework where vaccination rate, re-vaccination time, and non-pharmaceutical interventions (NPIs) are control variables to minimize infection levels. The optimization objective is defined using different norm-based measures of infected individuals. A numerical analysis of the model’s dynamic behavior under varying control parameters is conducted using path-following methods. The analysis focuses on the impacts of vaccination strategies and contact limitation measures. Bifurcation analysis reveals complex behaviors, including bistability, fold bifurcations, forward and backward bifurcations, highlighting the need for combined vaccination and contact control strategies to manage disease spread effectively.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"196 ","pages":"Article 116436"},"PeriodicalIF":5.3,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Adaptive neural finite-time tracking control based on modified command-filtered backstepping method for MIMO nonlinear systems

IF 5.3 1区数学

Chaos Solitons & Fractals Pub Date : 2025-04-19 DOI: 10.1016/j.chaos.2025.116407

Xu Zhao , Yang Gao , Haisong Huang , Qingsong Fan , Jiajia Chen , Muhammet Deveci , Weiping Ding

{"title":"Adaptive neural finite-time tracking control based on modified command-filtered backstepping method for MIMO nonlinear systems","authors":"Xu Zhao , Yang Gao , Haisong Huang , Qingsong Fan , Jiajia Chen , Muhammet Deveci , Weiping Ding","doi":"10.1016/j.chaos.2025.116407","DOIUrl":"10.1016/j.chaos.2025.116407","url":null,"abstract":"<div><div>This paper develops an adaptive neural finite-time tracking control scheme based on modified command-filtered backstepping control method (MCFBC) for multi-input and multi-output (MIMO) nonlinear systems. Firstly, by introducing some constant matrices, command-filtered backstepping control method (CFBC) is modified. Compared with CFBC, MCFBC ensures that virtual control signals are linearized, which lowers the complexity of the controller such that the control performance is elevated. Secondly, different from CFBC, MCFBC does not directly use the spectral boundedness of control directions in stability proof any more. Thirdly, lumped uncertainties are approximated by neural network (NN) and a more generalized inequality is proposed to surmount the technical difficulties of finite-time stability analysis. Fourthly, the singularity problem is circumvented. Command filters are introduced to remove the repeated differentiation of pseudocontrol signals. An error compensation system is constructed to lower the adverse effect from filter errors. This proposed controller guarantees that all signals in the closed-loop system converge to a bounded region within finite time and the system output can follow the given signal with a considerably small tracking error. Finally, flexible joint manipulations are used to validate this control scheme.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"196 ","pages":"Article 116407"},"PeriodicalIF":5.3,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0