数学最新文献_第5页

The sl(2)-weight system at c = 3/8 for graphs 图在c = 3/8时的sl(2)-权系统

IF 1 3区数学

European Journal of Combinatorics Pub Date : 2025-05-01 DOI: 10.1016/j.ejc.2025.104160

Daniil Fomichev , Maksim Karev

引用次数: 0

Complete threshold dynamics of a reaction–diffusion schistosomiasis model in different time-evolving domains 反应-扩散型血吸虫病模型在不同时间演化域的完全阈值动力学

IF 5.3 1区数学

Chaos Solitons & Fractals Pub Date : 2025-05-01 DOI: 10.1016/j.chaos.2025.116478

Yonghui Ren , Peng Wu

{"title":"Complete threshold dynamics of a reaction–diffusion schistosomiasis model in different time-evolving domains","authors":"Yonghui Ren , Peng Wu","doi":"10.1016/j.chaos.2025.116478","DOIUrl":"10.1016/j.chaos.2025.116478","url":null,"abstract":"<div><div>The significance of river and lake regions in the propagation of schistosomiasis cannot be overlooked, as this disease is transmitted predominantly through water. In this paper, we focus on the complete dynamics of a reaction–diffusion model for schistosomiasis, which accounts for domain that evolve over time. By employing theories of asymptotically autonomous and nonautonomous semiflows, we delineate the global dynamics of the system within domains that are fixed, asymptotically periodic, and bounded, with the dynamics being dictated by the basic reproduction number. Utilizing the sub-and supersolutions method alongside the comparison principle, we substantiate the threshold dynamics of the system in asymptotically unbounded domains. In numerical simulation part, we explore the influence of the evolving domain on the schistosomiasis transmission by comparing the basic reproduction numbers across various domains. Our findings reveal that the asymptotic growth and periodic changes in the size of these areas are pivotal in the transmission of schistosomiasis, with the growth of the regional evolution ratio being particularly conducive to the spread of the disease. These insights suggest that it is imperative for prevention and control authorities to enhance their schistosomiasis countermeasures, especially during the rainy seasons when the risk of transmission is significantly increased.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"197 ","pages":"Article 116478"},"PeriodicalIF":5.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143895459","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

Activation functions enabling the addition of neurons and layers without altering outcomes 激活功能可以在不改变结果的情况下增加神经元和层

IF 2.1 2区数学

Journal of Computational and Applied Mathematics Pub Date : 2025-05-01 DOI: 10.1016/j.cam.2025.116730

Sergio López-Ureña

引用次数: 0

Targeted attack in spatial networks with minimal collateral damage 在空间网络中以最小的附带损害进行目标攻击

IF 5.3 1区数学

Chaos Solitons & Fractals Pub Date : 2025-05-01 DOI: 10.1016/j.chaos.2025.116504

Keyuan Lai , An Zeng

{"title":"Targeted attack in spatial networks with minimal collateral damage","authors":"Keyuan Lai , An Zeng","doi":"10.1016/j.chaos.2025.116504","DOIUrl":"10.1016/j.chaos.2025.116504","url":null,"abstract":"<div><div>Targeted attacks in spatial networks have a wide range of applications in real systems such as transportation, power grids, and communication networks, but they may cause collateral damage in systems, so how to develop targeted attacks is an important research problem. This study introduces the reverse gradient attack (RGA), a novel efficient strategy designed to optimize attack precision while minimizing collateral damage. By incorporating spatial constraints and leveraging a gradient-based intensity mapping framework, RGA identifies the optimal attack centers for precise targeted interventions. A comprehensive evaluation across multiple real-world spatial networks demonstrates that RGA outperforms traditional methods in terms of precision and robustness, particularly in scenarios requiring minimal influence to non-target nodes. The study highlights a “black zone” phenomenon, referring to regions where increasing the attack radius paradoxically reduces the effectiveness of the attack, further highlighting the importance of carefully selecting the attack radius. The findings reveal RGA’s effectiveness in both random and topologically clustered target scenarios, suggesting the robustness of the methodology of targeted attacks in spatial networks.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"197 ","pages":"Article 116504"},"PeriodicalIF":5.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143891895","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

Improved LESO-based distributed adaptive fixed-time tracking control for vehicle platoon system with input saturation 输入饱和车辆排系统的改进基于leso的分布式自适应固定时间跟踪控制

IF 5.3 1区数学

Chaos Solitons & Fractals Pub Date : 2025-05-01 DOI: 10.1016/j.chaos.2025.116503

Linlin Liu , Liang Cao , Wenshuai Lin , Wenbin Xiao , Xiaomeng Li

{"title":"Improved LESO-based distributed adaptive fixed-time tracking control for vehicle platoon system with input saturation","authors":"Linlin Liu , Liang Cao , Wenshuai Lin , Wenbin Xiao , Xiaomeng Li","doi":"10.1016/j.chaos.2025.116503","DOIUrl":"10.1016/j.chaos.2025.116503","url":null,"abstract":"<div><div>With the continuous advancement of technology and the expansion of applications, vehicle platoon control is an important technology for improving road traffic efficiency and saving energy consumption. This paper proposes a distributed adaptive fixed-time disturbance rejection tracking control strategy with input saturation based on an improved linear extended state observer (LESO), ensuring the convergence of the tracking error. Firstly, a fixed-time controller is constructed to ensure that the system achieves the expected performance. The singularity problems in fixed-time control are effectively solved through power transformation schemes and the use of an input saturation estimator avoids the occurrence of input saturation phenomenon. With the help of the principle of deviation control, the deviation between the state variables and their observed values in LESO is improved. Theoretical proof and simulation demonstrate that the improved LESO can achieve better estimation accuracy. Finally, the control strategy is implemented to the vehicle platoon systems, and simulation results confirm the performance of the control strategy.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"197 ","pages":"Article 116503"},"PeriodicalIF":5.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143895458","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

Posets, their incidence algebras and relative operads, and the cohomology comparison theorem 偏序集，它们的关联代数和相对操作数，以及上同调比较定理

IF 1 3区数学

European Journal of Combinatorics Pub Date : 2025-04-30 DOI: 10.1016/j.ejc.2025.104162

V. Jacky III Batkam Mbatchou , Frédéric Patras , Calvin Tcheka

{"title":"Posets, their incidence algebras and relative operads, and the cohomology comparison theorem","authors":"V. Jacky III Batkam Mbatchou , Frédéric Patras , Calvin Tcheka","doi":"10.1016/j.ejc.2025.104162","DOIUrl":"10.1016/j.ejc.2025.104162","url":null,"abstract":"<div><div>Motivated by various developments in algebraic combinatorics and its applications, we investigate here the fine structure of a fundamental but little known theorem, the Gerstenhaber and Schack cohomology comparison theorem. The theorem classically asserts that there is a cochain equivalence between the usual singular cochain complex of a simplicial complex and the relative Hochschild complex of its incidence algebra, and a quasi-isomorphism with the standard Hochschild complex. Here, we will be mostly interested in its application to arbitrary posets (or, equivalently, finite topological spaces satisfying the <span><math><msub><mrow><mi>T</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span> separation axiom) and their incidence algebras. We construct various structures, classical and new, on the above two complexes: cosimplicial, differential graded algebra, operadic and brace algebra structures and show that the comparison theorem preserves all of them. These results provide non standard insights on links between the theory of posets, incidence algebras, endomorphism operads and finite and combinatorial topology. By <em>non standard</em>, we refer here to the use of <em>relative</em> versions of Hochschild complexes and operads.</div></div>","PeriodicalId":50490,"journal":{"name":"European Journal of Combinatorics","volume":"127 ","pages":"Article 104162"},"PeriodicalIF":1.0,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143885987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

The diameter of random Schreier graphs 随机Schreier图的直径

IF 1 3区数学

European Journal of Combinatorics Pub Date : 2025-04-30 DOI: 10.1016/j.ejc.2025.104164

Daniele Dona , Luca Sabatini

引用次数: 0

A simplified condition for quantile regression 分位数回归的简化条件

IF 0.9 4区数学

Statistics & Probability Letters Pub Date : 2025-04-30 DOI: 10.1016/j.spl.2025.110444

Liang Peng , Yongcheng Qi

引用次数: 0

Maxitive functions with respect to general orders 关于一般阶的最大函数

IF 3.2 1区数学

Fuzzy Sets and Systems Pub Date : 2025-04-30 DOI: 10.1016/j.fss.2025.109430

Michael Kupper , José M. Zapata

引用次数: 0

Exploring graphs with distinct M-eigenvalues: Product operation, Wronskian vertices, and controllability 探索具有不同m特征值的图：乘积运算，朗斯基顶点和可控性

IF 1 3区数学

Discrete Applied Mathematics Pub Date : 2025-04-30 DOI: 10.1016/j.dam.2025.04.055

Haiying Shan, Xiaoqi Liu

{"title":"Exploring graphs with distinct M-eigenvalues: Product operation, Wronskian vertices, and controllability","authors":"Haiying Shan, Xiaoqi Liu","doi":"10.1016/j.dam.2025.04.055","DOIUrl":"10.1016/j.dam.2025.04.055","url":null,"abstract":"<div><div>Let <span><math><msup><mrow><mi>G</mi></mrow><mrow><mi>M</mi></mrow></msup></math></span> denote the set of connected graphs with distinct <span><math><mi>M</mi></math></span>-eigenvalues. This paper explores the <span><math><mi>M</mi></math></span>-spectrum and eigenvectors of a new product <span><math><mrow><mi>G</mi><msub><mrow><mo>∘</mo></mrow><mrow><mi>C</mi></mrow></msub><mi>H</mi></mrow></math></span> of graphs <span><math><mi>G</mi></math></span> and <span><math><mi>H</mi></math></span>. We present the necessary and sufficient condition for <span><math><mrow><mi>G</mi><msub><mrow><mo>∘</mo></mrow><mrow><mi>C</mi></mrow></msub><mi>H</mi></mrow></math></span> to have distinct <span><math><mi>M</mi></math></span>-eigenvalues. Specifically, for the rooted product <span><math><mrow><mi>G</mi><mo>∘</mo><mi>H</mi></mrow></math></span>, we present a more concise and precise condition. A key concept, <span><math><mi>M</mi></math></span>-Wronskian vertex, which plays a crucial role in determining graph properties related to separability and construction of specific graph families, is investigated. We propose a novel method for constructing infinite pairs of non-isomorphic <span><math><mi>M</mi></math></span>-cospectral graphs in <span><math><msup><mrow><mi>G</mi></mrow><mrow><mi>M</mi></mrow></msup></math></span> by leveraging the structural properties of <span><math><mi>M</mi></math></span>-Wronskian vertex. Moreover, the necessary and sufficient condition for <span><math><mrow><mi>G</mi><mo>∘</mo><mi>H</mi></mrow></math></span> to be <span><math><mi>M</mi></math></span>-controllable is given.</div></div>","PeriodicalId":50573,"journal":{"name":"Discrete Applied Mathematics","volume":"373 ","pages":"Pages 125-136"},"PeriodicalIF":1.0,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143890818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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