Mathematics and Computers in Simulation最新文献_第3页

Fixed-time optimal bipartite containment fault-tolerant control for multi-agent systems under multiple faults and saturated actuation 多智能体系统在多故障饱和驱动下的固定时间最优二部容错控制

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2026-07-01 Epub Date: 2026-01-06 DOI: 10.1016/j.matcom.2026.01.001

Ning Xu , Li Tang , Abdullah A. Al-Barakati

{"title":"Fixed-time optimal bipartite containment fault-tolerant control for multi-agent systems under multiple faults and saturated actuation","authors":"Ning Xu , Li Tang , Abdullah A. Al-Barakati","doi":"10.1016/j.matcom.2026.01.001","DOIUrl":"10.1016/j.matcom.2026.01.001","url":null,"abstract":"<div><div>This paper addresses the fixed-time optimal bipartite containment control problem for nonlinear multi-agent systems under multiple simultaneous faults — including concurrent actuator and sensor faults — and input saturation. A key contribution is a unified disturbance-observer–based reinforcement learning framework that integrates fault tolerance with optimal control objectives. By designing a novel performance index function, the traditional containment control problem is reformulated as an optimal control problem, enabling an explicit trade-off between control accuracy and energy consumption. To solve the corresponding Hamilton–Jacobi–Bellman equation without relying on accurate system dynamics, a neural reinforcement learning algorithm with an identifier–critic–actor architecture is developed. A disturbance observer is incorporated to actively estimate and compensate for external disturbances, while an auxiliary system is introduced to alleviate input saturation effects. The resulting fixed-time optimal controller ensures that all bipartite containment errors converge to a small neighborhood of the origin within a fixed time independent of initial conditions, while maintaining uniform boundedness of all closed-loop signals. Simulation results validate the effectiveness and superiority of the proposed method in achieving simultaneous fault tolerance, disturbance rejection, and optimal performance under saturated actuation conditions.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":"245 ","pages":"Pages 242-259"},"PeriodicalIF":4.4,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038832","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

Multivalued extension of the Caristi-type theorem in semi-metric spaces and its numerical simulation 半度量空间中caristi型定理的多值推广及其数值模拟

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2026-07-01 Epub Date: 2026-01-22 DOI: 10.1016/j.matcom.2026.01.026

Pradip Debnath

{"title":"Multivalued extension of the Caristi-type theorem in semi-metric spaces and its numerical simulation","authors":"Pradip Debnath","doi":"10.1016/j.matcom.2026.01.026","DOIUrl":"10.1016/j.matcom.2026.01.026","url":null,"abstract":"<div><div>We present a novel extension of the Caristi-type fixed point theorem recently established by Zubelevich (2025) for single-valued mappings on complete semi-metric spaces to the multivalued setting. Specifically, we prove that, in a complete semi-metric space <span><math><mi>R</mi></math></span>, if a set-valued mapping <span><math><mrow><mi>F</mi><mo>:</mo><mi>R</mi><mo>→</mo><msup><mrow><mn>2</mn></mrow><mrow><mi>R</mi></mrow></msup></mrow></math></span> satisfies a generalized Caristi-type inequality involving a family of lower semi-continuous, bounded-from-below functions and a semi-metric structure, then <span><math><mi>F</mi></math></span> admits a fixed point. Our approach constructs a suitable selection from the multivalued map and applies Zubelevich’s partial order method in conjunction with Zorn’s lemma to ensure the existence of a fixed point. Furthermore, we establish a multivalued counterpart to Zubelevich’s noncompactness theorem: if one of the associated potential functions fails to attain its minimum, then the fixed point set of <span><math><mi>F</mi></math></span> is necessarily noncompact. These results provide the first known multivalued Caristi-type fixed point framework for semi-metric spaces, unifying and generalizing prior work in both metric and topological vector space settings. The results are further validated by a numerical simulation showing convergence of iterates under deterministic selections.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":"245 ","pages":"Pages 325-336"},"PeriodicalIF":4.4,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038830","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

A statistics-based simplification method to the Distribution Network Reconfiguration problem for large-scale networks 基于统计的大规模配电网重构问题简化方法

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2026-07-01 Epub Date: 2026-01-12 DOI: 10.1016/j.matcom.2026.01.008

A. Graine , N. Karnib , J.-P. Gaubert , D. Larraillet

{"title":"A statistics-based simplification method to the Distribution Network Reconfiguration problem for large-scale networks","authors":"A. Graine , N. Karnib , J.-P. Gaubert , D. Larraillet","doi":"10.1016/j.matcom.2026.01.008","DOIUrl":"10.1016/j.matcom.2026.01.008","url":null,"abstract":"<div><div>The Distribution Network Reconfiguration (DNR) consists of modifying the topology of a Distribution Network (DN) through the modification of the state of its switches, thus modifying the paths of power. It can be used to minimize losses or other physical quantities, while satisfying, among others, radial, electrical, and thermal constraints. It is an optimization problem of a type referred to as Mixed-Integer Programming (MIP). When the DNR is applied to large-scale DNs, which is the case for this paper since the aim is to optimize real networks for a French Distribution System Operator (DSO): this problem can be challenging to solve because the number of switches (and thus the number of binary variables) becomes very large, which can lead to a combinatorial explosion.</div><div>In this paper, a statistics-based simplification method is proposed to determine the most impactful switches for the DNR. The method can be fragmented into two phases: a training phase, then a deployment phase. Different strategies are tested and compared for the two phases. A simplified method is used for the training phase, during which the most impactful switches are identified. Then, these most impactful switches are used as decision variables in the deployment phase, while the non-impactful switches are considered as input parameters, hence greatly reducing the number of binary optimization variables. As a consequence, the computational time is decreased. The method’s performance is evaluated through simulations on a realistic 2 588-bus, 403-switch DN. Results show that the proposed method is able to speed up the computation.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":"245 ","pages":"Pages 176-191"},"PeriodicalIF":4.4,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038822","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

Modelling financial contagion and optimal policy design for bank runs and systemic risk 模拟金融传染和银行挤兑和系统性风险的最佳政策设计

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2026-07-01 Epub Date: 2026-01-03 DOI: 10.1016/j.matcom.2025.12.023

Samuel Asante Gyamerah , Emmanuel Afrifa , Perpetual Andam Boiquaye , Nelson Dzupire

{"title":"Modelling financial contagion and optimal policy design for bank runs and systemic risk","authors":"Samuel Asante Gyamerah , Emmanuel Afrifa , Perpetual Andam Boiquaye , Nelson Dzupire","doi":"10.1016/j.matcom.2025.12.023","DOIUrl":"10.1016/j.matcom.2025.12.023","url":null,"abstract":"<div><div>Bank runs can destabilize individual institutions and, through financial networks, spread into general economic crises. The study explores the interconnection of systemic risk in the banking system, emphasizing interbank networks as the primary means of propagating financial contagion. We propose a compartmental system through which contagion is propagated. The system classifies the banks in the network into six compartments (undistressed, exposed, distressed, liquid, run, and failed states). We capture the dynamics of distress transmission through interbank interactions and depositor behaviours. We derive the basic reproduction number <span><math><msub><mrow><mi>R</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span> to characterize the threshold conditions for systemic stability and identify both risk-free and risk-persistent equilibrium points. Through sensitivity experiments, we identify the parameters that exert the strongest influence on contagion dynamics—the contact rate between banks, the level of behavioural compliance, and transition intensities. Building on these insights, we formulate an optimal-control framework that incorporates three forms of intervention: deposit-insurance protection, policies aimed at calming depositors, and targeted liquidity intervention. Using Pontryagin’s Maximum Principle, we derive the time paths of these interventions that jointly reduce the spread of distress while keeping regulatory costs manageable. The numerical results highlight the importance of acting early: even a moderate level of deposit-insurance coverage, when implemented at the right moment, substantially dampens the transmission of shocks across the network. The study offers practical guidance for the design of policy tools intended to contain systemic risk in interconnected banking systems.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":"245 ","pages":"Pages 35-52"},"PeriodicalIF":4.4,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929178","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

Dynamic interplay of Allee effect and harvesting in a diseased amensalism model: Unraveling ecological complexity 在一个患病的仙人掌模型中，Allee效应和收获的动态相互作用：解开生态复杂性

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2026-07-01 Epub Date: 2026-01-19 DOI: 10.1016/j.matcom.2026.01.021

Sarita Bugalia , Sandeep Kumar , Jai Prakash Triapthi , Maia Martcheva

{"title":"Dynamic interplay of Allee effect and harvesting in a diseased amensalism model: Unraveling ecological complexity","authors":"Sarita Bugalia , Sandeep Kumar , Jai Prakash Triapthi , Maia Martcheva","doi":"10.1016/j.matcom.2026.01.021","DOIUrl":"10.1016/j.matcom.2026.01.021","url":null,"abstract":"<div><div>In this paper, we analyze the dynamics of an eco-epidemiological amensalism model involving three species, where the first species exhibits a weak Allee effect. In contrast, the second and third species are subjected to proportional harvesting. The proposed model assumes that the disease only affects the second species while the first species remains unaffected. We consider harvesting as a control parameter for both disease and amensalism dynamics. The amensalism functional response is modeled using the Holling type II response, while disease transmission follows a saturation incidence rate. Our primary mathematical objectives are to analyze the effects of the Allee parameter and harvesting on the system’s dynamics. By treating key parameters as bifurcation and threshold variables, the stability of all equilibria and the associated bifurcations are analyzed. The model exhibits a degenerate Bogdanov–Takens (BT), two saddle–node and three transcritical bifurcations. Conditions for both extinction and persistence are derived in terms of the harvesting rate. A critical threshold of harvesting is identified, beyond which the diseased species declines and the disease-free equilibrium becomes stable. Our findings reveal an upper limit of harvesting within which all species can coexist. However, the coexistence of all three species depends on initial conditions, leading to bistability. Notably, the Allee effect acts only on the first species, underlies the occurrence of a saddle–node bifurcation and eliminating equilibria for a certain parameter range, while leaving the other two species unaffected. These results provide quantitative insights into the interplay between the Allee effect and harvesting in shaping species coexistence and system dynamics.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":"245 ","pages":"Pages 295-324"},"PeriodicalIF":4.4,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038831","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

Percolation thresholds and epidemic spreading on small-world networks: Exact results and critical dynamics 小世界网络上的渗透阈值和流行病传播：精确结果和临界动力学

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2026-07-01 Epub Date: 2026-01-13 DOI: 10.1016/j.matcom.2026.01.011

Xiao-Long Peng , Shu-Yan Chang , Shanshan Chen , Gui-Quan Sun

{"title":"Percolation thresholds and epidemic spreading on small-world networks: Exact results and critical dynamics","authors":"Xiao-Long Peng , Shu-Yan Chang , Shanshan Chen , Gui-Quan Sun","doi":"10.1016/j.matcom.2026.01.011","DOIUrl":"10.1016/j.matcom.2026.01.011","url":null,"abstract":"<div><div>Percolation theory provides a powerful framework for understanding the emergence of large-scale epidemic outbreaks on complex networks. Building on the seminal work of Moore and Newman (2000), we revisit and extend percolation-based models of disease spread on small-world networks that incorporate both local connections and long-range shortcuts. Specifically, we resolve two previously unresolved cases by deriving exact analytical expressions for the bond percolation threshold at local connectivity <span><math><mrow><mi>K</mi><mo>=</mo><mn>3</mn></mrow></math></span>, and for the hybrid site-bond percolation threshold at <span><math><mrow><mi>K</mi><mo>=</mo><mn>2</mn></mrow></math></span>. These results advance the theoretical foundations of epidemic modelling on structured networks. Complementing these theoretical results, we conduct extensive numerical simulations to characterize critical behaviour of both pure bond and hybrid site-bond percolation processes. We find that percolation thresholds are highly sensitive to shortcut density and local connectivity. Notably, the average size of finite percolating clusters exhibits a pronounced peak at criticality, offering a reliable early-warning signal for epidemic onset. Furthermore, we observe a clear transition in cluster size distributions — from exponential decay to heavy-tailed forms — as the system approaches the percolation threshold, culminating in the emergence of a giant component indicative of a large-scale epidemic. Temporal simulations further reveal abrupt epidemic transitions as control parameters cross critical thresholds, in agreement with our percolation-based predictions. Collectively, our results establish the percolation framework as a powerful tool for capturing both structural and dynamical features of epidemic spreading on small-world networks.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":"245 ","pages":"Pages 192-211"},"PeriodicalIF":4.4,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038825","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

A semi-adaptive discrete variable method for emulating dual space fractional convection–diffusion quenching problems 模拟对偶空间分数对流扩散猝灭问题的半自适应离散变量方法

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2026-06-01 Epub Date: 2025-12-31 DOI: 10.1016/j.matcom.2025.12.019

Lin Zhu , Rumin Dong , Qin Sheng

引用次数: 0

Diverse soliton solutions to the conformable Ivancevic option pricing model via the modified generalized Riccati equation mapping method 用改进的广义Riccati方程映射法求解符合Ivancevic期权定价模型的各种孤子解

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2026-06-01 Epub Date: 2026-01-03 DOI: 10.1016/j.matcom.2025.12.022

Muhammad Amin S. Murad , Usman Younas , Homan Emadifar , Mujahid Iqbal , Wael W. Mohammed , Karim K. Ahmed

{"title":"Diverse soliton solutions to the conformable Ivancevic option pricing model via the modified generalized Riccati equation mapping method","authors":"Muhammad Amin S. Murad , Usman Younas , Homan Emadifar , Mujahid Iqbal , Wael W. Mohammed , Karim K. Ahmed","doi":"10.1016/j.matcom.2025.12.022","DOIUrl":"10.1016/j.matcom.2025.12.022","url":null,"abstract":"<div><div>In this paper, we employ the modified generalized Riccati equation approach to derive a variety of exact solutions for the Ivancevic option pricing model incorporating the conformable derivative. The Ivancevic option pricing equation is structured using an adaptive nonlinear Schrödinger equation, which describes the option-pricing wave function based on time and stock price. This equation captures the typical regulated Brownian motion seen in financial markets. The predictive nature of the model allows financial analysts to forecast option prices under varying market conditions. The model helps traders to price complex options with greater accuracy by considering nonlinear market dynamics. A variety of soliton solutions to the conformable Ivancevic model are derived, including dark, mixed dark–bright, singular, bell-shaped, and wave solutions. To provide deeper insights into their dynamical properties and physical significance, these solutions are visualized through three-dimensional plots, two-dimensional plots, and contour plots. The graphical representations underscore the intricate dynamics and potential financial applications of soliton solutions within the conformable framework, demonstrating their relevance in option pricing theory and nonlinear financial modeling.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":"244 ","pages":"Pages 213-225"},"PeriodicalIF":4.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927610","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

A unified one-step joint optimization framework for sparse subspace clustering and self-constrained spectral clustering 稀疏子空间聚类与自约束谱聚类的统一一步联合优化框架

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2026-06-01 Epub Date: 2025-12-18 DOI: 10.1016/j.matcom.2025.12.011

Chengmao Wu, Yilong Zhu

{"title":"A unified one-step joint optimization framework for sparse subspace clustering and self-constrained spectral clustering","authors":"Chengmao Wu, Yilong Zhu","doi":"10.1016/j.matcom.2025.12.011","DOIUrl":"10.1016/j.matcom.2025.12.011","url":null,"abstract":"<div><div>Subspace clustering aims to explore multiple low-dimensional subspaces within data to more effectively represent the essential structure of high-dimensional datasets. Traditional subspace clustering methods typically employ a two-step strategy: first, constructing a similarity matrix based on the relevance between samples, and then performing spectral clustering on this matrix. Although these approaches achieve local optimality at each stage, they do not guarantee the global optimality of the clustering results. To address these issues, this study introduces an algorithm that integrates subspace clustering and spectral clustering, enabling the simultaneous optimization of the similarity matrix and the clustering indicator matrix in a low-dimensional space. In the subspace clustering module, an -<span><math><msub><mrow><mi>ℓ</mi></mrow><mrow><mn>0</mn><mo>,</mo><mn>2</mn></mrow></msub></math></span>norm constraint is applied to the self-representation coefficient matrix to enhance the sparsity of the similarity matrix. For the spectral clustering component, we employ self-constrained spectral clustering to improve the graph-cut performance, resulting in higher-quality clustering indicator matrices. To integrate the two components, we develop a unified one-step joint optimization framework that addresses the clustering problem through a proximal alternating minimization approach with proven convergence. Its innovation lies in constructing a simultaneous optimization model for the similarity and cluster indicator matrices, effectively solved using the proximal alternating minimization (PAM) method to tackle the problem's inherent nonlinearity. The proposed algorithm has demonstrated strong performance across various datasets, outperforming eight representative comparison algorithms.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":"244 ","pages":"Pages 19-44"},"PeriodicalIF":4.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841722","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

Dynamic analysis and optimal control of a stochastic tumor-immune model 随机肿瘤免疫模型的动态分析与最优控制

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2026-06-01 Epub Date: 2025-12-18 DOI: 10.1016/j.matcom.2025.12.010

Xi Wang, Zijian Liu, Yuanshun Tan, Yu Mu

引用次数: 0