IF 2.7 2区数学

Chaos Pub Date : 2025-05-01 DOI: 10.1063/5.0254365

Li-Lei Han, Lang Zeng, Hayoung Choi, Ying-Cheng Lai, Younghae Do

引用次数: 0

Self-sustained and chaotic oscillations with excursions and asymmetry in oscillators with nonlinear damping singularities and exponential terms. 具有非线性阻尼奇点和指数项的振子中带有漂移和不对称性的自持续混沌振荡。

IF 2.7 2区数学

Chaos Pub Date : 2025-05-01 DOI: 10.1063/5.0255896

L-S Banga, R Mboyo Kouayep, J M'Boliguipa, P Woafo

{"title":"Self-sustained and chaotic oscillations with excursions and asymmetry in oscillators with nonlinear damping singularities and exponential terms.","authors":"L-S Banga, R Mboyo Kouayep, J M'Boliguipa, P Woafo","doi":"10.1063/5.0255896","DOIUrl":"https://doi.org/10.1063/5.0255896","url":null,"abstract":"We study, theoretically and experimentally with microcontrollers, the dynamics of second-order nonlinear differential equations with rational damping terms having singularities and exponential damping terms. Because of the singularities, one finds a series of excursions of the dynamical variable from a permanent self-sustained or forced oscillatory state to instantaneous high values before returning back to oscillations with almost constant amplitude. Chaotic behaviors with excursions are observed even in the autonomous case. The occurrence of chaos in the autonomous system indicates that one way to generate chaos is the use of singularities in the damping term. In the case of the oscillator with the exponential damping term, one finds asymmetric self-sustained oscillations as well as asymmetric chaotic dynamics. The theoretical results are confirmed by the experimental investigation in a mixed circuit containing both discrete electrical components and a microcontroller. To the best of our knowledge, this work offers a place to three interesting novelties in nonlinear dynamics. The first one is the analysis of oscillators with singularities and exponential terms in their damping coefficient. The second is the use of a mixed circuit consisting of discrete electric components in series with a microcontroller generating nonlinear characteristics. The third one is the fact that chaos can be generated because of the presence of the singularities in the damping term.","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"35 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143984980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Two-phase flow pattern transition behaviors on experimental established ordinal pattern networks. 两相流型转换行为在实验建立的有序型网上。

IF 2.7 2区数学

Chaos Pub Date : 2025-05-01 DOI: 10.1063/5.0254994

Meng Du, Zhenqian Zhang, Yang Cao, Yuliang Liu, Weidong Cao, Zhong-Ke Gao

{"title":"Two-phase flow pattern transition behaviors on experimental established ordinal pattern networks.","authors":"Meng Du, Zhenqian Zhang, Yang Cao, Yuliang Liu, Weidong Cao, Zhong-Ke Gao","doi":"10.1063/5.0254994","DOIUrl":"https://doi.org/10.1063/5.0254994","url":null,"abstract":"Identifying the flow pattern transition dynamics is a fundamental challenge in modeling a two-phase flow system. In this paper, we investigate the gas-liquid two-phase flow pattern transition behaviors with analyzing the topology structures of the experimental established gas-liquid two-phase flow complex networks. First, we carry out a series of gas-liquid two-phase flow experiments in a vertical 50 mm inner diameter pipe. During the experiments, the two-phase flow fluctuation signals are collected and used to establish the ordinal pattern complex networks, which represent different flow patterns. Then, we employ a K-core decomposition method to identify the hierarchical structures of our established flow pattern networks. We find that the decay rate of the K-core size is sensitive to the flow conditions and can be a potential metric for identifying the flow pattern transitions. Additionally, we analyze the network homology persistence, which indicates the loop structures in the flow pattern networks. The persistence indexes-maximum persistence and persistence entropy-are used to investigate the flow pattern oscillatory behaviors along with the flow pattern transitions. This research provides a novel way for investigating the flow pattern transition behaviors of a gas-liquid two-phase flow system, which are expected to be applicable in other complex fluid systems.","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"35 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144076161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Evolutionary game dynamics of index insurance with refund or non-refund risk sharing mechanism. 退退与不退风险分担机制下指数保险的演化博弈动力学。

IF 2.7 2区数学

Chaos Pub Date : 2025-05-01 DOI: 10.1063/5.0270353

Lichen Wang, Shijia Hua, Yuyuan Liu, Liang Zhang, Linjie Liu

{"title":"Evolutionary game dynamics of index insurance with refund or non-refund risk sharing mechanism.","authors":"Lichen Wang, Shijia Hua, Yuyuan Liu, Liang Zhang, Linjie Liu","doi":"10.1063/5.0270353","DOIUrl":"https://doi.org/10.1063/5.0270353","url":null,"abstract":"Index insurance, by utilizing preset indices, effectively mitigates the moral hazards and adverse selection inherent in traditional insurance. Yet, the mismatch between these indices and actual losses, known as basis risk, severely hinders its broader adoption. The existing study has proposed a risk sharing mechanism, in which individuals who have not suffered losses but have received compensation assist those who have suffered losses but have not received compensation. Nonetheless, due to individual profit-seeking behavior, this mechanism is difficult to implement in practice. In this study, we construct a threshold-discounted index insurance game model including new risk sharing mechanisms. In the model, individuals purchasing index insurance are required to contribute to a risk sharing pool to compensate those facing basis risk. We analyze two mechanisms for handling the funds: a refund mechanism and a non-refund mechanism, depending on whether the funds are returned to the policyholders when no basis risk occurs. We find that low basis risk remains key for the sale of index insurance under both mechanisms. Moreover, with an appropriate risk sharing ratio, the introduction of a risk sharing pool significantly increases the adoption of index insurance. The refund mechanism, with its stronger risk sharing capability, proves more popular. Additionally, larger group sizes or lower collective thresholds can enhance the stability and aid capacity of the risk sharing pool, thereby further increasing adoption rates. Finally, insurance companies should accurately assess the risk aversion level of the population, as it is also a key factor affecting insurance sales.","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"35 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143974710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Phase and gain stability for adaptive dynamical networks. 自适应动态网络的相位和增益稳定性。

IF 2.7 2区数学

Chaos Pub Date : 2025-05-01 DOI: 10.1063/5.0249706

Nina Kastendiek, Jakob Niehues, Robin Delabays, Thilo Gross, Frank Hellmann

引用次数: 0

Multiscale temporal weighted coupling correlation detrended analysis for multivariate nonstationary series. 多变量非平稳序列的多尺度时间加权耦合相关去趋势分析。

IF 2.7 2区数学

Chaos Pub Date : 2025-05-01 DOI: 10.1063/5.0263273

Bei Tan, Fang Wang, Zu-Guo Yu

{"title":"Multiscale temporal weighted coupling correlation detrended analysis for multivariate nonstationary series.","authors":"Bei Tan, Fang Wang, Zu-Guo Yu","doi":"10.1063/5.0263273","DOIUrl":"https://doi.org/10.1063/5.0263273","url":null,"abstract":"Understanding coupling correlations in multivariate time series is crucial for analyzing the complex dynamics of real world systems, where interactions often vary across different time scales. In this paper, we propose two novel methods: temporal weighted coupling correlation detrended analysis and its multiscale extension and multiscale temporal weighted coupling correlation detrended analysis (MTWCCDA). These two methods improve the trend removal process by incorporating temporal weighting, leading to a more robust and accurate characterization of coupling correlation behavior. We evaluate the performance of the proposed methods using synthetic data from several perspectives: accuracy of scaling index estimation, robustness to trends, sensitivity to noise and various components, and the necessity of MTWCCDA for capturing coupling behavior across scales. Additionally, MTWCCDA is applied to study the coupling behaviors of six air pollutants in Hunan Province, China, at different time scales. A Q-statistic quantifies each pollutant's contribution to the system's multifractal coupling correlation across scales, while scaling indices are used for clustering 14 cities, revealing regional variations in coupling behavior. The results provide valuable insights into pollutant interdependencies, aiding in the development of targeted air quality management strategies. The proposed methods offer a robust framework for investigating dynamic coupling behaviors in complex, multiscale, and non-stationary multivariate time series.","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"35 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144132058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Multiclass models for nonlinear classification via nonparallel hyperplane support vector machine. 基于非并行超平面支持向量机的多类非线性分类模型。

IF 2.7 2区数学

Chaos Pub Date : 2025-05-01 DOI: 10.1063/5.0260466

Miguel Carrasco, Carla Vairetti, Julio López, Sebastián Maldonado

引用次数: 0

Generalized network dismantling based on cost-aware source-sampling betweenness. 基于成本感知的源采样间性的广义网络分解。

IF 2.7 2区数学

Chaos Pub Date : 2025-05-01 DOI: 10.1063/5.0245472

Jihui Han, Chengyi Zhang, Gaogao Dong, Longfeng Zhao, Yuefeng Shi, Yijiang Zou

引用次数: 0

Learning the dynamics of symmetry-reduced chaotic attractors from data. 从数据中学习对称简化混沌吸引子的动力学。

IF 2.7 2区数学

Chaos Pub Date : 2025-05-01 DOI: 10.1063/5.0224262

Simon Kneer, Nazmi Burak Budanur

引用次数: 0

Evolutionary dynamics in state-feedback public goods games with peer punishment. 具有同伴惩罚的状态反馈公共物品博弈的演化动力学。

IF 2.7 2区数学

Chaos Pub Date : 2025-04-01 DOI: 10.1063/5.0268194

Qiushuang Wang, Xiaojie Chen, Attila Szolnoki

{"title":"Evolutionary dynamics in state-feedback public goods games with peer punishment.","authors":"Qiushuang Wang, Xiaojie Chen, Attila Szolnoki","doi":"10.1063/5.0268194","DOIUrl":"https://doi.org/10.1063/5.0268194","url":null,"abstract":"Public goods game serves as a valuable paradigm for studying the challenges of collective cooperation in human and natural societies. Peer punishment is often considered an effective incentive for promoting cooperation in such contexts. However, previous related studies have mostly ignored the positive feedback effect of collective contributions on individual payoffs. In this work, we explore global and local state-feedback, where the multiplication factor is positively correlated with the frequency of contributors in the entire population or within the game group, respectively. By using replicator dynamics in an infinite well-mixed population, we reveal that state-based feedback plays a crucial role in alleviating the cooperative dilemma by enhancing and sustaining cooperation compared to the feedback-free case. Moreover, when the feedback strength is sufficiently strong or the baseline multiplication factor is sufficiently high, the system with local state-feedback provides full cooperation, hence supporting the \"think globally, act locally\" principle. Besides, we show that the second-order free-rider problem can be partially mitigated under certain conditions when the state-feedback is employed. Importantly, these results remain robust with respect to variations in punishment cost and fine.","PeriodicalId":9974,"journal":{"name":"Chaos","volume":"35 4","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143975785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

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