Chaos, Solitons and Fractals: X最新文献

{"title":"Buildup of different emission regimes in a nonlinear polarization rotation modelocked all-fiber laser","authors":"C. Cuadrado-Laborde ,&nbsp;L. Tendela ,&nbsp;E. Silvestre ,&nbsp;A. Díez ,&nbsp;J.L. Cruz ,&nbsp;M.V. Andrés","doi":"10.1016/j.csfx.2024.100114","DOIUrl":"10.1016/j.csfx.2024.100114","url":null,"abstract":"<div><p>We investigated experimentally and theoretically the buildup of light pulses in an erbium-doped sub-MHz all-fiber laser modelocked by nonlinear polarization rotation. We were able to study the buildup of two different emission regimes: standard solitons and noise-like pulses. In each case, we were able to determine the round-trips required to achieve a stable emission state. Temporal traces and optical spectra of single pulses were measured along the start-up transient of the laser. The experimental results were also confirmed by numerical simulations. Under the specific conditions of this laser, the soliton regime takes about 400 round-trips to reach single-pulse emission. In the noise-like pulse regime, it takes only 20 round-trips for the characteristics of noise-like pulses to show up; although a more steady-state emission is reached also at about 400 round-trips.</p></div>","PeriodicalId":37147,"journal":{"name":"Chaos, Solitons and Fractals: X","volume":"13 ","pages":"Article 100114"},"PeriodicalIF":0.0,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590054424000113/pdfft?md5=616778a49162dba29e2986132b6e3375&pid=1-s2.0-S2590054424000113-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141278634","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}

{"title":"Modeling the spread of infections during an epidemiological outbreak using an improved mathematical model","authors":"Nouf Abd Elmunim","doi":"10.1016/j.csfx.2024.100111","DOIUrl":"https://doi.org/10.1016/j.csfx.2024.100111","url":null,"abstract":"<div><p>Pandemics occur periodically worldwide. An accurate forecasting model is therefore essential to estimate the effect of the pandemic and plan accordingly. This research aims to provide a solution that could help the world predict the number of infection cases during pandemics and prepare to accommodate subsequent cases. The mathematical Multiplicative Holt–Winter (M-HW) model was improved regarding the data used to provide an accurate forecast. The model was applied to the Coronavirus (COVID-19) data, where COVID-19 is the recent pandemic that affected all nations worldwide since 2019. Two different periods in Saudi Arabia were modelled to estimate COVID-19 cases. Based on the daily confirmed cases in February 2023 and February 2022, the model showed accuracy of 99.51 % and 99.66 %, respectively. A MAPE value in February 2023 ranges between 0.015 and 1.07, while it ranges between 0.032 and 2.269 in February 2022. Additionally, the RMSE in February 2023 was 0.35, while in February 2022 it was 6.88. The model proved to be accurate and highly efficient. Thus, M-HW model is useful to forecast the number of cases in different regions in case of a pandemic, which makes a significant contribution to mitigating the spread of the virus minimizing the epidemiological spread impact on healthcare systems and focusing on managing and containing the epidemiological spread.</p></div>","PeriodicalId":37147,"journal":{"name":"Chaos, Solitons and Fractals: X","volume":"12 ","pages":"Article 100111"},"PeriodicalIF":0.0,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590054424000083/pdfft?md5=b3fceba1f3a2cfb95e31d29b4c6d7b36&pid=1-s2.0-S2590054424000083-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141097743","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}

{"title":"A powerful tool for dealing with high-dimensional fractional-order systems with applications to fractional Emden–Fowler systems","authors":"Shaher Momani ,&nbsp;Iqbal M. Batiha ,&nbsp;Amira Abdelnebi ,&nbsp;Iqbal H. Jebril","doi":"10.1016/j.csfx.2024.100110","DOIUrl":"https://doi.org/10.1016/j.csfx.2024.100110","url":null,"abstract":"<div><p>In this study, an approximation solution for a high-dimensional system in terms of the Caputo fractional derivative operator is obtained using the improved modified fractional Euler method, or IMFEM for short. To accomplish this aim, a result that can transform such a system into a double-equation, one-dimensional fractional-order system, is provided theoretically. Some physical applications, including fractional-order systems of equations of Emden–Fowler type, are discussed, and their graphs are plotted using MATLAB to demonstrate the IMFEM schema’s validity.</p></div>","PeriodicalId":37147,"journal":{"name":"Chaos, Solitons and Fractals: X","volume":"12 ","pages":"Article 100110"},"PeriodicalIF":0.0,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590054424000071/pdfft?md5=9b81310b312b8c4d94bafcc3219b5acc&pid=1-s2.0-S2590054424000071-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140880420","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}

{"title":"Analysis of the hate speech and racism co-existence dissemination model with optimal control strategies","authors":"Shewafera Wondimagegnhu Teklu,&nbsp;Yohannes Fissha Abebaw","doi":"10.1016/j.csfx.2024.100109","DOIUrl":"10.1016/j.csfx.2024.100109","url":null,"abstract":"<div><p>Hate speech, racism, and their co-existence are the human mind infections that are major factors that affect the living conditions of people, societal well-being, and political stability, economic and social disturbance throughout the world especially in underdeveloped nations of the world. The main objective of this study is to formulate and analyze the hate-speech and racism co-existence model with optimal control strategies and investigate the optimal effects of protection and improvement (rehabilitation) strategies to minimize and tackle the hate speech and racism co-existence dissemination in the community. In this study, we have computed the hate speech sub-model, the racism sub-model, and the hate speech and racism co-existence model equilibrium points and analyzed their stabilities, using the next generation operator approach all the models' effective reproduction numbers are computed, examined the phenomenon of backward bifurcation whenever the model effective reproduction number is less than one where at which both the positive co-existence free equilibrium point and the positive co-existence dominance equilibrium point exist simultaneously. To achieve the objective minimizing the hate speech and racism co-existence dissemination dynamics by implementing the efforts towards the protection and improvement (rehabilitation) strategies, the optimal control problem is re-formulated, and optimal control analysis is performed for the co-existence model using Pontryagin's maximum principle. Numerical simulations using MATLAB ode45 solver with fourth-order Runge-Kutta numerical methods to investigate the behavior of the co-existence model solutions and to explore the optimal effects of the protections and improvements (rehabilitation) strategies for the hate speech and racism co-existence dynamics are then performed. From the results, we observed that implementing the protection and improvement (rehabilitation) strategies simultaneously is the most effective approach to minimize and tackle the speech and racism co-existence propagation in the community.</p></div>","PeriodicalId":37147,"journal":{"name":"Chaos, Solitons and Fractals: X","volume":"12 ","pages":"Article 100109"},"PeriodicalIF":0.0,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S259005442400006X/pdfft?md5=75e65e5b2529cb0598c0287bb117f478&pid=1-s2.0-S259005442400006X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140794304","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}

{"title":"An investigation into the controllability of multivalued stochastic fractional differential inclusions","authors":"Pallavi Bedi ,&nbsp;Anoop Kumar ,&nbsp;Gaurav Deora ,&nbsp;Aziz Khan ,&nbsp;Thabet Abdeljawad","doi":"10.1016/j.csfx.2024.100107","DOIUrl":"https://doi.org/10.1016/j.csfx.2024.100107","url":null,"abstract":"<div><p>This research aims to investigate the approximate controllability of multivalued impulsive stochastic fractional differential inclusions in Hilbert space with <span><math><mi>ABC</mi></math></span> fractional-order derivatives. First, we confirm the existence of mild solutions for the proposed control system using stochastic analysis, resolvent operator theory, and the fixed point technique. Secondly, we discuss a new set of sufficient conditions for the approximate controllability of the systems. The results are obtained under the assumption that the associated linear system is approximately controllable. Finally, an example is provided to illustrate the obtained results.</p></div>","PeriodicalId":37147,"journal":{"name":"Chaos, Solitons and Fractals: X","volume":"12 ","pages":"Article 100107"},"PeriodicalIF":0.0,"publicationDate":"2024-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590054424000046/pdfft?md5=603bdc490fff51f10cc1d86094b79842&pid=1-s2.0-S2590054424000046-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139914857","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}

{"title":"Moment dynamics for stochastic resonance in active rotator systems","authors":"Ruonan Liu ,&nbsp;Yanmei Kang","doi":"10.1016/j.csfx.2024.100108","DOIUrl":"10.1016/j.csfx.2024.100108","url":null,"abstract":"<div><p>We investigate the dynamics of active rotator systems by the moment closure method based on matching derivatives. This method is illustrated and verified in terms of three systems: the single-element rotator, the two coupled rotators and the mean field coupled rotators. Using the moment closure method, we study the effect of common noise on active rotator systems from the perspective of stochastic resonance. It is shown that the noise-induced stochastic resonance and parameter-induced stochastic resonance occur in the above three systems. Our observation discloses that the two kinds of stochastic resonance effect can be enhanced by both increasing coupling strength and the number of coupled rotators.</p></div>","PeriodicalId":37147,"journal":{"name":"Chaos, Solitons and Fractals: X","volume":"12 ","pages":"Article 100108"},"PeriodicalIF":0.0,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590054424000058/pdfft?md5=a57145da4e925db6951ecb1fe1954791&pid=1-s2.0-S2590054424000058-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139897014","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}

{"title":"Stability, numerical simulations, and applications of Helmholtz-Duffing fractional differential equations","authors":"M. Sivashankar ,&nbsp;S. Sabarinathan ,&nbsp;Kottakkaran Sooppy Nisar ,&nbsp;C. Ravichandran ,&nbsp;B.V. Senthil Kumar","doi":"10.1016/j.csfx.2024.100106","DOIUrl":"https://doi.org/10.1016/j.csfx.2024.100106","url":null,"abstract":"<div><p>The Helmholtz-Duffing equation with the Caputo fractional order derivative will be introduced in this article. We employ the fixed point theory to establish the existence and uniqueness results and prove the Hyers-Ulam stability. Drone applications for controlling the synthesis of external forces in torque, angular velocity, and projection served as a source of motivation. In the end, we developed numerical simulations to support our theoretical findings.</p></div>","PeriodicalId":37147,"journal":{"name":"Chaos, Solitons and Fractals: X","volume":"12 ","pages":"Article 100106"},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590054424000034/pdfft?md5=8003257519d61daeafdbe87043227ee4&pid=1-s2.0-S2590054424000034-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139726028","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}

{"title":"Stability analysis and suppress chaos in the generalized Lorenz model","authors":"Hamza Rouah","doi":"10.1016/j.csfx.2024.100104","DOIUrl":"https://doi.org/10.1016/j.csfx.2024.100104","url":null,"abstract":"<div><p>In this paper, we investigate the stability analysis of the equilibrium points and the influence of the orientation on the suppression of chaotic behavior of the generalized Lorenz system proposed. A three-dimensional system model is obtained using the spectral method. We proved that the first equilibrium point is globally asymptotically stable and the other two equilibria are asymptotically stable under certain conditions on the control parameters <em>σ</em>, <em>P</em>, <em>r</em>, <span><math><msub><mrow><mi>b</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> and <span><math><msub><mrow><mi>b</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>. These theoretical results are supported by numerical simulations. Also, we showed that chaos can be suppressed by a boundary crisis or period-doubling by choosing an appropriate tilt angle. Bifurcation diagrams are drawn to confirm these results.</p></div>","PeriodicalId":37147,"journal":{"name":"Chaos, Solitons and Fractals: X","volume":"12 ","pages":"Article 100104"},"PeriodicalIF":0.0,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590054424000010/pdfft?md5=2af1780e57995df68f25df25ef0450ec&pid=1-s2.0-S2590054424000010-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139714719","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}

{"title":"Parameters estimation, global sensitivity analysis and model fitting for the dynamics of Plutella xylostella infestations in a cabbage biomass","authors":"Daniel Paul ,&nbsp;Maranya Makuru Mayengo ,&nbsp;Salamida Daudi","doi":"10.1016/j.csfx.2024.100105","DOIUrl":"https://doi.org/10.1016/j.csfx.2024.100105","url":null,"abstract":"<div><p><em>Plutella xylostella</em>, commonly called Diamondback moth (DBM), a highly destructive and rapidly spreading agricultural pest originally from Europe. This pest poses a significant threat to global food security, with estimates suggesting that periodic outbreaks of Diamondback moth lead to annual crop losses of up to $US <span><math><mn>4</mn><mo>−</mo><mn>5</mn></math></span> billion worldwide. Given the potential for such substantial losses, it is crucial to employ various methods and techniques to understand the factors affecting the interaction between Diamondback moths and cabbage plants, which, in turn, impact cabbage biomass. In this paper, we propose a deterministic ecological model to capture the dynamics of <em>Plutella xylostella</em> infestations in cabbage biomass. The model is designed based on the life cycle stages of the pest, aiming at targeting the specific stage effectively. The synthetic data is generated using Least Square Algorithm through addition of Gaussian noise into numerically obtained values from existing literature to simulate real-world data. Global sensitivity analysis was done through Latin Hypercube sampling, highlights the significance of parameters such as <span><math><mi>ψ</mi><mo>,</mo><msub><mrow><mi>α</mi></mrow><mrow><mi>E</mi></mrow></msub></math></span> and <em>δ</em> positively influence the growth of the diamondback moth in a cabbage biomass. In light of these findings, the study proposes that control strategies should be specifically directed towards these sensitive parameters. By doing so, we mitigate the pest population and enhance cabbage production.</p></div>","PeriodicalId":37147,"journal":{"name":"Chaos, Solitons and Fractals: X","volume":"12 ","pages":"Article 100105"},"PeriodicalIF":0.0,"publicationDate":"2024-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590054424000022/pdfft?md5=47b89b1fcbcafa81de662e752f02f6e5&pid=1-s2.0-S2590054424000022-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139674345","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}

{"title":"A new method for a semi-positone Hadamard fractional boundary value problem","authors":"Rui Liu ,&nbsp;Chengbo Zhai ,&nbsp;Jing Ren","doi":"10.1016/j.csfx.2023.100102","DOIUrl":"https://doi.org/10.1016/j.csfx.2023.100102","url":null,"abstract":"<div><p>A Hadamard fractional boundary value problem with semi-positone nonlinearity is studied in this paper, and the local existence and uniqueness of solutions are derived by a recent fixed point theorem involving with increasing <span><math><mi>φ</mi><mo>−</mo><mo>(</mo><mi>h</mi><mo>,</mo><mi>r</mi><mo>)</mo></math></span>-concave operators defined on ordered spaces. This is an unprecedented approach to solve the semi-positone problems. In practice, this method has a wider range of applicability since it can obtain the local uniqueness of the solutions. Furthermore, we can approximate the unique solution by constructing convergent iterative sequences. In the end, a persuasive example is provided to illustrate that the theoretical results we obtained are applicable and valid.</p></div>","PeriodicalId":37147,"journal":{"name":"Chaos, Solitons and Fractals: X","volume":"12 ","pages":"Article 100102"},"PeriodicalIF":0.0,"publicationDate":"2023-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S259005442300012X/pdfft?md5=5a814fb3810acba3cbb5e6c5efee0ae6&pid=1-s2.0-S259005442300012X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138501762","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}