Mathematics and Computers in Simulation最新文献_第4页

Patterns in soil organic carbon dynamics: Integrating microbial activity, chemotaxis and data-driven approaches

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2025-02-28 DOI: 10.1016/j.matcom.2025.02.019

Angela Monti , Fasma Diele , Deborah Lacitignola , Carmela Marangi

{"title":"Patterns in soil organic carbon dynamics: Integrating microbial activity, chemotaxis and data-driven approaches","authors":"Angela Monti , Fasma Diele , Deborah Lacitignola , Carmela Marangi","doi":"10.1016/j.matcom.2025.02.019","DOIUrl":"10.1016/j.matcom.2025.02.019","url":null,"abstract":"<div><div>Models of soil organic carbon (SOC) frequently overlook the effects of spatial dimensions and microbiological activities. In this paper, we focus on two reaction–diffusion chemotaxis models for SOC dynamics, both supporting chemotaxis-driven instability and exhibiting a variety of spatial patterns as stripes, spots and hexagons when the microbial chemotactic sensitivity is above a critical threshold. We use symplectic techniques to numerically approximate chemotaxis-driven spatial patterns and explore the effectiveness of the piecewise Dynamic Mode Decomposition (pDMD) to reconstruct them. Moreover, we analyse the predictive performance of the pDMD for moderate time horizons. Our findings show that pDMD is effective at precisely recreating and predicting chemotaxis-driven spatial patterns, therefore broadening the range of application of the method to classes of solutions different than Turing patterns. By validating its efficacy across a wider range of models, this research lays the groundwork for applying pDMD to experimental spatiotemporal data, advancing predictions crucial for soil microbial ecology and agricultural sustainability.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":"234 ","pages":"Pages 86-101"},"PeriodicalIF":4.4,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The singular wave in a pressureless hydrodynamic model

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2025-02-26 DOI: 10.1016/j.matcom.2025.02.018

Zhijian Wei, Lihui Guo

{"title":"The singular wave in a pressureless hydrodynamic model","authors":"Zhijian Wei, Lihui Guo","doi":"10.1016/j.matcom.2025.02.018","DOIUrl":"10.1016/j.matcom.2025.02.018","url":null,"abstract":"<div><div>In this paper, we investigate the non-classical wave for a pressureless hydrodynamic model with the flux perturbed term by the Riemann problem and a singularity formation. All the possible Riemann solutions, the combination of two contact discontinuities <span><math><mrow><msub><mrow><mi>J</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>+</mo><msub><mrow><mi>J</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span>, and a delta shock wave <span><math><mrow><mi>δ</mi><mi>S</mi></mrow></math></span>, are constructed in fully explicit forms. It should be mentioned that the delta shock wave appears in the solution if and only if the flux perturbed parameter <span><math><mi>ɛ</mi></math></span> satisfies some specific condition. Due to the particularity of the delta shock wave in the Riemann solutions, we investigate the formation of singularity, namely, the traffic density blowing up under certain data. Moreover, its result gives an example of the conjecture proposed by Majda [Springer New York, 1984]: “<em>If a hyperbolic system of conservation laws is totally linearly degenerate, then the system has smooth global solutions when the initial data are smooth, unless the solution itself blows up in a finite time.</em>” We further explore and discuss their asymptotic behaviors to analyze the effect of <span><math><mi>ɛ</mi></math></span>, in which the delta shock wave and vacuum state solutions for a pressureless hydrodynamic model can be obtained by <span><math><mrow><msub><mrow><mi>J</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>+</mo><msub><mrow><mi>J</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span> as <span><math><mi>ɛ</mi></math></span> tends to 0. In addition, we offer some typical numerical simulations that are identical well to our theoretical results and provide a more intuitive way to observe the singular wave.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":"234 ","pages":"Pages 15-30"},"PeriodicalIF":4.4,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519888","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

IMACS Calendar of Events

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2025-02-25 DOI: 10.1016/S0378-4754(25)00065-5

引用次数: 0

News of IMACS

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2025-02-25 DOI: 10.1016/S0378-4754(25)00064-3

引用次数: 0

Analysis of a stochastic HIV/AIDS model with commercial heterosexual activity and Ornstein–Uhlenbeck process 带有商业异性性行为和奥恩斯坦-乌伦贝克过程的随机艾滋病毒/艾滋病模型分析

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2025-02-24 DOI: 10.1016/j.matcom.2025.02.020

Yicheng Hao , Yantao Luo , Jianhua Huang , Long Zhang , Zhidong Teng

{"title":"Analysis of a stochastic HIV/AIDS model with commercial heterosexual activity and Ornstein–Uhlenbeck process","authors":"Yicheng Hao , Yantao Luo , Jianhua Huang , Long Zhang , Zhidong Teng","doi":"10.1016/j.matcom.2025.02.020","DOIUrl":"10.1016/j.matcom.2025.02.020","url":null,"abstract":"<div><div>Considering the effects of commercial heterosexual behavior and environmental noise on the dynamics of HIV/AIDS disease, in this study, we establish a stochastic HIV/AIDS model that combines commercial heterosexual behavior and ln-type Ornstein–Uhlenbeck process. Firstly, for the deterministic model, i.e., the stochastic noise is not taken into account, the local and global asymptotic stability of the equilibria in terms of basic reproduction number <span><math><msub><mrow><mi>R</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span> are given. Then, for the stochastic model, the uniqueness and existence of global solutions, the existence of stationary distribution under <span><math><mrow><msubsup><mrow><mi>R</mi></mrow><mrow><mn>0</mn></mrow><mrow><mi>S</mi></mrow></msubsup><mo>></mo><mn>1</mn></mrow></math></span>, and the exponential extinction of HIV-positive patients under <span><math><mrow><msubsup><mrow><mi>R</mi></mrow><mrow><mn>0</mn></mrow><mrow><mi>E</mi></mrow></msubsup><mo><</mo><mn>1</mn></mrow></math></span> can all be obtained by constructing suitable random Lyapunov functions. In particular, under certain conditions, specific expression of the probability density function near the quasi-endemic equilibrium of the stochastic system can be obtained. Finally, numerical simulations indicate that controlling noise intensity, as well as commercial heterosexual activities, can help control the transmission of HIV.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":"234 ","pages":"Pages 50-72"},"PeriodicalIF":4.4,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143528696","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

Numerical solution of a two-dimensional rock-glacier flow model via the pressure method

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2025-02-24 DOI: 10.1016/j.matcom.2025.01.028

Elishan Christian Braun , Daniela Mansutti , Kumbakonam R. Rajagopal

{"title":"Numerical solution of a two-dimensional rock-glacier flow model via the pressure method","authors":"Elishan Christian Braun , Daniela Mansutti , Kumbakonam R. Rajagopal","doi":"10.1016/j.matcom.2025.01.028","DOIUrl":"10.1016/j.matcom.2025.01.028","url":null,"abstract":"<div><div>Literature confirms the crucial influence on glacier and rock glacier flow of non-viscous deformations together with temperature impact. This observation suggests numerical glaciologists ought to reconsider the established mathematical modeling based on the representation of ice as a power-law viscous fluid and the Glen’s law. Along this line, we propose the numerical solution of a two-dimensional rock-glacier flow model, based on a constitutive law of second grade of complexity two, as just published for a one-dimensional set-up by two of the authors. With the representation of the composition of the rocky ice as a mixture of ice and rock and sand grains, and the inclusion of the local impact of pressure and of thermal effects, this model has allowed the reproduction of borehole measurement data from alpine glacier internal sliding motion via a similarity solution of the flow governing equations. Here, the adopted numerical procedure uses a second order finite difference scheme and imposes the incompressibility constrain up to computer accuracy via the pressure method, that we have extended from Newtonian computational fluid dynamics. This method solves the governing equations for the flow in primitive variables with the advantage that no pre-/post-processing is required; in addition, it avoids splitted solution of the Poisson equation for pressure which might be source of undesired numerical mass unbalancing. The results of a numerical test on the Murtel-Corvatsch alpine glacier flow, reporting satisfactory matching with published on-field observations, are presented.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":"234 ","pages":"Pages 102-112"},"PeriodicalIF":4.4,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Controlling chaos and mixed mode oscillations in a Bertrand duopoly game with homogeneous expectations and quadratic cost functions

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2025-02-22 DOI: 10.1016/j.matcom.2025.02.015

Mourad Azioune, Mohammed-Salah Abdelouahab

引用次数: 0

On the stability of finite-volume schemes on non-uniform meshes

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2025-02-21 DOI: 10.1016/j.matcom.2025.02.017

P.A. Bakhvalov, M.D. Surnachev

引用次数: 0

An agile modeling framework for population dynamics

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2025-02-21 DOI: 10.1016/j.matcom.2025.02.013

Laurent Attias , Vincent Siess , Stéphane Labbé

引用次数: 0

Multi-material topology optimization using isogeometric method based reaction–diffusion level set techniques

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2025-02-20 DOI: 10.1016/j.matcom.2025.02.010

Harsh Kumar, Sourav Rakshit

{"title":"Multi-material topology optimization using isogeometric method based reaction–diffusion level set techniques","authors":"Harsh Kumar, Sourav Rakshit","doi":"10.1016/j.matcom.2025.02.010","DOIUrl":"10.1016/j.matcom.2025.02.010","url":null,"abstract":"<div><div>This work presents a new approach to multi-material topology optimization (MMTO) using Isogeometric Analysis (IGA) based reaction–diffusion equation (RDE) level set method. Level set based topology optimization, frequently used for achieving clear material boundaries and avoiding checkerboard patterns in topology optimization problems is further augmented by RDEs which enhance numerical stability of the solver. The multi-material formulation uses a blended combination of different level-set functions to ensure that each point in the domain corresponds to a single material. In this work, isogeometric analysis (IGA) is used for the first time in RDE-based level set for solving MMTO problems. The same Non-Uniform Rational B-Splines (NURBS) basis function is used for approximating state variables, geometry modeling and level set function, thus facilitating seamless coupling between analysis and product design. Using the IGAFEM toolbox (Nguyen et al., 2015), MMTO is performed for a few benchmark problems for varying material composition and mesh sizes. Results indicate that satisfactory distribution of material is achieved in all the MMTO examples and bi-quadratic element based IGA is a competent tool to be applied in RDE-based level set method for topology optimization. Future work will focus on using the same IGA framework for further shape optimization of the designed structures to produce fabrication ready CAD models.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":"233 ","pages":"Pages 530-552"},"PeriodicalIF":4.4,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471319","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