Applied Mathematics and Computation最新文献

{"title":"Nonlinear rank scaling and hidden structure in NHS expenditure transparency data","authors":"Animotu Mohammed ,&nbsp;Golnaz Shahtahmassebi ,&nbsp;Haroldo V. Ribeiro ,&nbsp;Peter Scriven ,&nbsp;Jack Sutton ,&nbsp;Quentin S. Hanley","doi":"10.1016/j.amc.2026.129971","DOIUrl":"10.1016/j.amc.2026.129971","url":null,"abstract":"<div><div>A variety of transparency initiatives have been introduced by governments to reduce corruption and allow citizens to independently evaluate the effectiveness and efficiency of spending. In 2010, the UK government mandated transparency for many expenditures exceeding £25,000. The resulting data is dispersed across a range of governmental organizations and presents an opportunity to understand expenditure at scale, interrogate organizational structures and develop transparency measures. Here, we focus on data from the top two layers of the National Health Service (NHS) within England, including NHS England (NHSE) and Integrated Care Boards (ICBs). As one of the largest government run healthcare organizations in the world and potentially the sixth largest employer globally, the NHS provides a distinctive case for studying healthcare delivery, contractor dynamics, and organizational self-organization. We find that limiting transparency to larger transactions conceals a substantial share of spending from scrutiny, including most transactions. The rank-frequency distributions of suppliers, expense types, and spending categories exhibit multiple scaling regimes similar to patterns observed in word frequency and urban scaling studies indicating these methodologies can be deployed to analyze financial transparency data at scale.</div></div>","PeriodicalId":55496,"journal":{"name":"Applied Mathematics and Computation","volume":"521 ","pages":"Article 129971"},"PeriodicalIF":3.4,"publicationDate":"2026-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146095740","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}

{"title":"Adaptive parameter-space refinement and Markov state models for eco-epidemiological dynamics","authors":"Eymard Hernández-López ,&nbsp;Mohammad Sharif Ullah ,&nbsp;Giovanni Wences ,&nbsp;Jin Wang","doi":"10.1016/j.amc.2026.129974","DOIUrl":"10.1016/j.amc.2026.129974","url":null,"abstract":"<div><div>We propose a computational framework that combines Adaptive Mesh Refinement in Parameter Space (AMR-PS), ensemble stochastic simulation, and Markov state model (MSM) coarse-graining to characterize metastable dynamics in an infection-predator-prey eco-epidemiological system. By adaptively refining regions near bifurcations, the strategy dramatically reduces the cost of exploring high-dimensional parameter spaces while preserving fidelity. Ensemble simulations capture the stochastic pathways connecting metastable states, highlighting regimes in which noise qualitatively reshapes basins of attraction. MSM coarse-graining supplies interpretable macrostates and transition matrices that permit efficient computation of quantities of interest, and that faithfully summarize long-time behavior. Applied to representative eco-epidemiological regimes, the workflow identifies parameter regions where stochasticity most realistically reflects the deterministic bifurcation structure, quantifies escape times between endemic and disease-extinction basins, and could provide practical diagnostics for ecological management. The method is scalable, modular, and applicable to multiscale problems where rare events and parametric sensitivity influence complex system dynamics.</div></div>","PeriodicalId":55496,"journal":{"name":"Applied Mathematics and Computation","volume":"521 ","pages":"Article 129974"},"PeriodicalIF":3.4,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146071593","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}

{"title":"Neural-network-based asynchronous security control for delayed Markov jump systems with imperfect transition probabilities via dynamic-memory event-triggered mechanism","authors":"Mengchen Wang,&nbsp;Haibo Bao","doi":"10.1016/j.amc.2026.129973","DOIUrl":"10.1016/j.amc.2026.129973","url":null,"abstract":"<div><div>In this article, we tackle the problem of realizing boundedness for delayed Markov jump systems (MJSs) with deception attacks and imperfect transition probabilities. To alleviate the burden of communication and conserve bandwidth in the communication network channel, a novel model-dependent dynamic-memory event-triggered mechanism (DMETM) is designed. Different from the general dynamic event-triggered mechanism (ETM), the designed DMETM includes historical trigger data in its triggering conditions, so it is able to dynamically adjust data transmission according to the long-term changes in the system state, thereby improving resource utilization. A hidden Markov model (HMM) with unmeasured probabilities is employed to comprehensively characterize plant-controller asynchrony. Moreover, deception attacks, considering the vulnerability of communication links, are taken into account. While existing studies typically assume bounded false data injection in MJSs, establishing accurate bounds in practical scenarios remains challenging. Considering this problem, a neural network-based asynchronous memory compensation feedback controller is developed, which effectively identifies and mitigates the impact of deception attacks. By leveraging a Lyapunov-Krasovskii functional (LKF), sufficient conditions for bounded in probability of the closed-loop system are derived. The effectiveness of the theoretical analysis is illustrated through an illustrative example.</div></div>","PeriodicalId":55496,"journal":{"name":"Applied Mathematics and Computation","volume":"521 ","pages":"Article 129973"},"PeriodicalIF":3.4,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146072038","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}

{"title":"The equitable chromatic number of circulant graphs with maximum degree at most 4","authors":"Xiaoyu Jin ,&nbsp;Guiying Yan ,&nbsp;Weihua Yang ,&nbsp;Shuang Zhao","doi":"10.1016/j.amc.2026.129962","DOIUrl":"10.1016/j.amc.2026.129962","url":null,"abstract":"<div><div>A graph <span><math><mrow><mi>G</mi><mo>=</mo><mo>(</mo><mi>V</mi><mo>,</mo><mi>E</mi><mo>)</mo></mrow></math></span> is <em>equitably k-colorable</em> [1] if its vertex set <em>V</em> can be partitioned into <em>k</em> independent sets <span><math><mrow><msub><mi>V</mi><mn>1</mn></msub><mo>,</mo><mo>…</mo><mo>,</mo><msub><mi>V</mi><mi>k</mi></msub></mrow></math></span> such that <span><math><mrow><mrow><mo>|</mo><mrow><mo>|</mo></mrow><msub><mi>V</mi><mi>s</mi></msub><mrow><mo>|</mo><mo>−</mo><mo>|</mo></mrow><msub><mi>V</mi><mi>t</mi></msub><mrow><mo>|</mo></mrow><mo>|</mo></mrow><mo>≤</mo><mn>1</mn></mrow></math></span> for all <em>s, t</em>. The minimum such <em>k</em> is referred to as the <em>equitable chromatic number</em> of <em>G</em>, denoted <span><math><mrow><msub><mi>χ</mi><mo>=</mo></msub><mrow><mo>(</mo><mi>G</mi><mo>)</mo></mrow></mrow></math></span>.</div><div>Meyer conjectured that for any graph <em>G</em> that is neither a complete graph <em>K_m</em> nor an odd cycle <span><math><msub><mi>C</mi><mrow><mn>2</mn><mi>m</mi><mo>+</mo><mn>1</mn></mrow></msub></math></span>, the inequality <span><math><mrow><msub><mi>χ</mi><mo>=</mo></msub><mrow><mo>(</mo><mi>G</mi><mo>)</mo></mrow><mo>≤</mo><mstyle><mi>Δ</mi></mstyle><mrow><mo>(</mo><mi>G</mi><mo>)</mo></mrow></mrow></math></span> holds. The decoding scheduling of multi-edge type QC-LDPC codes in channel coding can be regarded as an equitable coloring problem of a circulant graph. Motivated by the NP-hardness of determining optimal equitable colorings in general, we focus on circulant graphs with Δ(<em>G</em>) ≤ 4. We show that if <span><math><mrow><mi>gcd</mi><mrow><mo>(</mo><msub><mi>d</mi><mn>2</mn></msub><mo>,</mo><mi>n</mi><mo>)</mo></mrow><mo>∤</mo><msub><mi>d</mi><mn>1</mn></msub><mo>.</mo><mi>t</mi><mi>e</mi><mi>x</mi><mi>t</mi><mrow><mi>a</mi><mi>n</mi><mi>d</mi></mrow><mo>.</mo><mi>g</mi><mi>c</mi><mi>d</mi><mrow><mo>(</mo><msub><mi>d</mi><mn>1</mn></msub><mo>,</mo><mi>n</mi><mo>)</mo></mrow><mo>∤</mo><msub><mi>d</mi><mn>2</mn></msub><mo>,</mo></mrow></math></span> then the circulant graph <em>G</em>(<em>n</em>; {<em>d</em>₁, <em>d</em>₂}) satisfies <span><math><mrow><msub><mi>χ</mi><mo>=</mo></msub><mrow><mo>(</mo><mi>G</mi><mrow><mo>(</mo><mi>n</mi><mo>;</mo><mrow><mo>{</mo><msub><mi>d</mi><mn>1</mn></msub><mo>,</mo><msub><mi>d</mi><mn>2</mn></msub><mo>}</mo></mrow><mo>)</mo></mrow><mo>)</mo></mrow><mo>=</mo><mn>2</mn><mspace></mspace><mtext>or</mtext><mspace></mspace><mn>3</mn><mo>≤</mo><mstyle><mi>Δ</mi></mstyle><mrow><mo>(</mo><mi>G</mi><mo>)</mo></mrow><mo>.</mo></mrow></math></span></div></div>","PeriodicalId":55496,"journal":{"name":"Applied Mathematics and Computation","volume":"521 ","pages":"Article 129962"},"PeriodicalIF":3.4,"publicationDate":"2026-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146039518","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}

{"title":"STWCR: Weak collocation regression for revealing hidden stochastic dynamics from single trajectory data","authors":"Yan Jiang ,&nbsp;Zhijun Zeng ,&nbsp;Wuyue Yang ,&nbsp;Liu Hong ,&nbsp;Pipi Hu ,&nbsp;Yi Zhu","doi":"10.1016/j.amc.2026.129958","DOIUrl":"10.1016/j.amc.2026.129958","url":null,"abstract":"<div><div>Revealing hidden stochastic dynamics from observation data is of great importance in applications. Traditional methods usually require a large number of independent trajectories to obtain the probability distributions at several time snapshots. This paper proposes a fast and accurate regression method to obtain the stochastic dynamics from a single trajectory. If the stochastic system possesses a stationary distribution, we can utilize the ergodicity and the Weak Collocation Regression method, which is a fast method based on the weak form and sparse regression to solve inverse problems of partial differential equations related to probability density functions, to extract the score function of the stationary distribution from the single trajectory data without high cost. Then a novel expression of the drift term in terms of the score function and the diffusion term can be established, based on which we can extract the drift and diffusion terms through the Weak Collocation Regression method again. Our method has a high efficiency and low requirements for the trajectory data. Its outstanding performance has been verified through extensive numerical experiments, including non-gradient drift, multi-scale and high-dimensional problems.</div></div>","PeriodicalId":55496,"journal":{"name":"Applied Mathematics and Computation","volume":"521 ","pages":"Article 129958"},"PeriodicalIF":3.4,"publicationDate":"2026-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146039601","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}

{"title":"An efficient and accurate numerical modeling for measuring moisture content profiles in an unsaturated porous medium","authors":"Sanjay L. Gosiya,&nbsp;Vikas H. Pradhan","doi":"10.1016/j.amc.2026.129961","DOIUrl":"10.1016/j.amc.2026.129961","url":null,"abstract":"<div><div>The Richards’ equation (RE), a non-linear elliptic-parabolic partial differential equation, is extensively used to simulate the flow processes in the unsaturated porous medium. This equation’s coefficients include two highly non-linear functions associated with unsaturated hydraulic conductivity, soil water potential, and soil water content. Various standard models are available in the literature to express these non-linear functions, potentially leading to significantly different outcomes in unsaturated flow problems. van Genuchten model is most widely used to express these non-linear functions for measuring accurate moisture content profiles. This paper presents the numerical results of a mixed form of RE based on this model using the Crank-Nicolson finite difference scheme. We compare the obtained numerical results with the available analytical and experimental results to verify the model. Accurate numerical results are also presented by comparing them with those obtained from Hydrus-1D, a widely used numerical tool for solving the RE. Notwithstanding, the numerical results are extended in 2D and 3D.</div></div>","PeriodicalId":55496,"journal":{"name":"Applied Mathematics and Computation","volume":"521 ","pages":"Article 129961"},"PeriodicalIF":3.4,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033537","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}

{"title":"Dynamic event-triggered prescribed time bipartite consensus for matrix-weighted HMASs under asynchronous attacks","authors":"Shuangfei Yin ,&nbsp;Xiuxia Yin ,&nbsp;Zhiwei Gao","doi":"10.1016/j.amc.2026.129957","DOIUrl":"10.1016/j.amc.2026.129957","url":null,"abstract":"<div><div>This article is centered on event-triggered prescribed-time bipartite output consensus issue for matrix-weighted heterogeneous multi-agent systems under asynchronous DoS attacks, where the dependencies between adjacent agents are characterized by the matrix weights of the edges within the network. First, the system suffering from invalid attack is considered as a switching system. Then, by limiting the duration of the valid attack, a novel prescribed-time bipartite compensator with a static event-triggered mechanism is introduced to track the leader’s state for this category of generalized networks. In order to reduce communication between agents to a greater extent, we introduce a prescribed-time bipartite compensator with a dynamic event-triggered mechanism. Moreover, we demonstrate that neither mechanism exhibits Zeno behavior. Then, through compensator, a distributed state-feedback control protocol and an output-feedback control protocol are designed to achieve prescribed-time bipartite output consensus. Finally, simulation examples are presented to validate the validity of the main results.</div><div><strong>Key words:</strong> Asynchronous DoS attacks; Prescribed-time consensus; Matrix-weighted networks; Dynamic event-triggered mechanism; Bipartite consensus.</div></div>","PeriodicalId":55496,"journal":{"name":"Applied Mathematics and Computation","volume":"520 ","pages":"Article 129957"},"PeriodicalIF":3.4,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014490","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}

{"title":"Continuous bounded control of feedforward nonlinear systems with low-order power and nonlinear growth rate","authors":"Liang Liu,&nbsp;Rulan Bai,&nbsp;Gang Sun","doi":"10.1016/j.amc.2026.129964","DOIUrl":"10.1016/j.amc.2026.129964","url":null,"abstract":"<div><div>This paper concentrates on the global strong stabilization for a type of feedforward nonlinear systems subject to the low-order power and nonlinear growth rate. On the strength of the bottom-up recursive design philosophy and the introduction of proper coordinate changes, the continuous and bounded state feedback controller is constructed in an explicit form. Under the generalized Lyapunov stability criterion, it is proved that the developed control scheme ensures that the trivial solution of the closed-loop system (CLS) is globally strongly stable (GSS). Two examples are given to show the feasibility of the developed control approach.</div></div>","PeriodicalId":55496,"journal":{"name":"Applied Mathematics and Computation","volume":"520 ","pages":"Article 129964"},"PeriodicalIF":3.4,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014496","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}

{"title":"Memory capacity and decision preference co-shape cooperation in public goods games","authors":"Jingchu Jia ,&nbsp;Luhe Yang ,&nbsp;Duoxing Yang ,&nbsp;Lianzhong Zhang","doi":"10.1016/j.amc.2026.129956","DOIUrl":"10.1016/j.amc.2026.129956","url":null,"abstract":"<div><div>Empirically grounded bounded rationality decision-making, when information exchange is lacking, can be abstracted as an aspiration-driven dynamic mechanism within anonymous evolutionary games. Prospect Theory, meanwhile, provides a behavioral economics-based qualitative description for such decision-making. Therefore, we establish a micro-dynamic model based on Prospect Theory, incorporating psychological reference point dynamics, heterogeneous memory mechanisms, and asymmetric strategy updating dynamics. We systematically examine the influence of individual cognitive and behavioral parameters on the evolution of cooperation. Through Monte Carlo simulations and asynchronous update mechanisms, it reveals the complex interaction among factors such as memory capacity, decision preference, strategy updating sensitivity, synergy factor, and initial cooperation proportion. Findings indicate that the effect of memory capacity on cooperation strongly depends on decision preferences, long memory significantly promotes cooperation only when individuals exhibit more greedy as defectors. Strategy updating sensitivity can either enhance group steady-state cooperation level or compromise system stability. The synergy factor forms positive synergy with the memory mechanism by amplifying cooperation payoffs. Additionally, group steady-state cooperation levels are independent of initial conditions. These findings emphasize the condition-dependent nature of cooperation promotion. We suggest that future research should pay more attention to the important role of bounded rationality in modeling human decision-making behavior.</div></div>","PeriodicalId":55496,"journal":{"name":"Applied Mathematics and Computation","volume":"521 ","pages":"Article 129956"},"PeriodicalIF":3.4,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145996323","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}

{"title":"A robust exact Riemann solver for a laminar two-phase flow model with two layers","authors":"Lilu Sahu,&nbsp;T. Raja Sekhar","doi":"10.1016/j.amc.2026.129960","DOIUrl":"10.1016/j.amc.2026.129960","url":null,"abstract":"<div><div>In this work, we analyze the solution of the Riemann problem for a quasilinear hyperbolic system of partial differential equations which describes the laminar two-phase flow model with two velocities. We explicitly construct rarefaction waves and shock waves with the help of the Riemann invariants and the Rankine-Hugoniot conditions, respectively. By using the continuity of averaged velocity and total density, we reduce the system of governing partial differential equations to a system of nonlinear algebraic equations and solve them exactly. Also resolve the complete wave structure of the two-layer two-phase flows. Various possible test cases are explored based on the wave configuration to assess the robustness of the proposed Riemann solver. Additionally we implement three finite volume schemes based on Godunov-type, whose solutions are independent of the proposed Riemann solver, to validate our analytical solution.</div></div>","PeriodicalId":55496,"journal":{"name":"Applied Mathematics and Computation","volume":"520 ","pages":"Article 129960"},"PeriodicalIF":3.4,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014495","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}