Journal of Computational and Applied Mathematics最新文献_第8页

A frequency-independent solver for systems of linear ordinary differential equations 线性常微分方程系统的频率无关解算器

IF 2.1 2区数学

Journal of Computational and Applied Mathematics Pub Date : 2025-04-19 DOI: 10.1016/j.cam.2025.116696

Tony Hu, James Bremer

{"title":"A frequency-independent solver for systems of linear ordinary differential equations","authors":"Tony Hu, James Bremer","doi":"10.1016/j.cam.2025.116696","DOIUrl":"10.1016/j.cam.2025.116696","url":null,"abstract":"<div><div>When a system of first order linear ordinary differential equations has eigenvalues of large magnitude, its solutions generally exhibit complicated behaviour, such as high-frequency oscillations, rapid growth or rapid decay. The cost of representing such solutions using standard techniques grows with the magnitudes of the eigenvalues. As a consequence, the running times of standard solvers for ordinary differential equations also grow with the size of these eigenvalues. The solutions of scalar equations with slowly-varying coefficients, however, can be represented via slowly-varying phase functions at a cost which is bounded independent of the magnitudes of the eigenvalues of the corresponding coefficient matrix. Here we couple an existing solver for scalar equations which exploits this observation with a well-known technique for transforming a system of linear ordinary differential equations into scalar form. The result is a method for solving a large class of systems of linear ordinary differential equations in time independent of the magnitudes of the eigenvalues of their coefficient matrices. We discuss the results of numerical experiments demonstrating the properties of our algorithm.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"470 ","pages":"Article 116696"},"PeriodicalIF":2.1,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143864104","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

Optimal control of linear fractional differential equations in the Caputo sense 卡普托意义下线性分数阶微分方程的最优控制

IF 2.1 2区数学

Journal of Computational and Applied Mathematics Pub Date : 2025-04-19 DOI: 10.1016/j.cam.2025.116707

José Villa-Morales , Luis Rincón , Gerardo Becerra-Guzmán

引用次数: 0

Invertible matrices under non-Archimedean absolute value and its inverse 非阿基米德绝对值下的可逆矩阵及其逆

IF 2.1 2区数学

Journal of Computational and Applied Mathematics Pub Date : 2025-04-19 DOI: 10.1016/j.cam.2025.116700

Suhua Li, Chaoqian Li

{"title":"Invertible matrices under non-Archimedean absolute value and its inverse","authors":"Suhua Li, Chaoqian Li","doi":"10.1016/j.cam.2025.116700","DOIUrl":"10.1016/j.cam.2025.116700","url":null,"abstract":"<div><div>Invertible matrices play a crucial role in various areas of mathematics, science and engineering. Although there are many ways to determine whether a matrix is invertible or not, it is still a fundamental and an important research work in linear algebra, especially in large-scale numerical computations. Based on the non-Archimedean absolute value, we in this paper present a new class of invertible matrices called <em>doubly strictly diagonally dominant matrices under non-Archimedean absolute value</em> (<em>DSDD</em><span><math><msub><mrow></mrow><mrow><mi>n</mi><mo>.</mo><mi>A</mi><mo>.</mo></mrow></msub></math></span> <em>matrices</em>). It includes the <em>strictly diagonally dominant matrices under non-Archimedean absolute value</em> (<em>SDD</em><span><math><msub><mrow></mrow><mrow><mi>n</mi><mo>.</mo><mi>A</mi><mo>.</mo></mrow></msub></math></span> <em>matrices</em>) presented by Nica and Sprague in [The American Mathematical Monthly, 130 (2023) 267-275]. Some examples are given to show the relationships of <em>SDD</em><span><math><msub><mrow></mrow><mrow><mi>n</mi><mo>.</mo><mi>A</mi><mo>.</mo></mrow></msub></math></span> <em>matrices</em>, <em>DSDD</em><span><math><msub><mrow></mrow><mrow><mi>n</mi><mo>.</mo><mi>A</mi><mo>.</mo></mrow></msub></math></span> <em>matrices</em>, <em>SDD matrices</em> (<em>strictly diagonally dominant matrices under Archimedean absolute value</em>), <em>DSDD matrices</em> (<em>doubly strictly diagonally dominant matrices under Archimedean absolute value</em>), and <em>H-matrices</em>. Moreover, it is proved that the inverse of <em>DSDD</em><span><math><msub><mrow></mrow><mrow><mi>n</mi><mo>.</mo><mi>A</mi><mo>.</mo></mrow></msub></math></span> <em>matrices</em> is also <em>DSDD</em><span><math><msub><mrow></mrow><mrow><mi>n</mi><mo>.</mo><mi>A</mi><mo>.</mo></mrow></msub></math></span> in some cases, which displays remarkable difference with the inverse of <em>DSDD matrices</em> and <em>SDD matrices</em>.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"470 ","pages":"Article 116700"},"PeriodicalIF":2.1,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143863984","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

Symmetric structured finite element model updating with prescribed partial eigenvalues while maintaining no spillover 对称结构有限元模型在保持无溢出的前提下，以规定的部分特征值进行更新

IF 2.1 2区数学

Journal of Computational and Applied Mathematics Pub Date : 2025-04-19 DOI: 10.1016/j.cam.2025.116698

H. Lalhriatpuia, Tanay Saha

引用次数: 0

Computationally efficient selection criterion of initial equation in STLN-based structured low-rank approximation 基于stn的结构化低秩逼近中初始方程的计算效率选择准则

IF 2.1 2区数学

Journal of Computational and Applied Mathematics Pub Date : 2025-04-19 DOI: 10.1016/j.cam.2025.116703

Natsuki Yoshino , Akira Tanaka

{"title":"Computationally efficient selection criterion of initial equation in STLN-based structured low-rank approximation","authors":"Natsuki Yoshino , Akira Tanaka","doi":"10.1016/j.cam.2025.116703","DOIUrl":"10.1016/j.cam.2025.116703","url":null,"abstract":"<div><div>The problem of structured low-rank approximation (SLRA) of a given matrix arises in a wide range of applications. This problem can be solved by the structured total least norm (STLN) method, which formulates it as a linear equation called an “initial equation”. Because this equation directly impacts the performance of STLN-based SLRA, certain selection criteria have been proposed. However, these criteria are computationally intensive and their theoretical validity has not been sufficiently investigated. In this paper, we theoretically analyze the relationship between the original problem and an initial equation, and subsequently propose a novel selection criterion with a computational order of <span><math><mrow><mi>O</mi><mrow><mo>(</mo><msup><mrow><mi>n</mi></mrow><mrow><mn>3</mn></mrow></msup><mo>)</mo></mrow></mrow></math></span>, in contrast to the complexity of <span><math><mrow><mi>O</mi><mrow><mo>(</mo><msup><mrow><mi>n</mi></mrow><mrow><mn>4</mn></mrow></msup><mo>)</mo></mrow></mrow></math></span> incurred by conventional methods. We also demonstrate numerical experiments for Sylvester matrices to confirm that our selection criterion reduces not only the selection time of the initial equation, but also the overall calculation time of the STLN-based SLRA.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"470 ","pages":"Article 116703"},"PeriodicalIF":2.1,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143860596","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

Optimizing the thermal efficiency and drug delivery to narrowing arteries with silver-gold nanoparticles: A numerical study 优化热效率和药物输送到狭窄的动脉与银-金纳米粒子：一个数值研究

IF 2.1 2区数学

Journal of Computational and Applied Mathematics Pub Date : 2025-04-19 DOI: 10.1016/j.cam.2025.116723

Vinoth Kumar B , Sreenivasulu P , Poornima T

{"title":"Optimizing the thermal efficiency and drug delivery to narrowing arteries with silver-gold nanoparticles: A numerical study","authors":"Vinoth Kumar B , Sreenivasulu P , Poornima T","doi":"10.1016/j.cam.2025.116723","DOIUrl":"10.1016/j.cam.2025.116723","url":null,"abstract":"<div><div>Gold and silver nanoparticles are gaining attention as advanced tools for drug delivery, largely due to their ability to carry medications and facilitate imaging. By simulating blood flow in these constricted environments, the research aims to assess how these nanoparticles behave and interact within the arteries. This study delves into the potential application of gold (Au) and silver (Ag) nanoparticles in narrowed arteries (stenosis) analyzed through the use of computer simulations. The primary goal is to determine if Au and Ag nanoparticles can enhance blood flow and mitigate the severity of stenosis, thus offering a novel approach to treatment. Specifically, the study examines the impact of increasing the volume fraction of gold nanoparticles on blood flow dynamics and temperature distribution. The analysis also incorporates the effects of thermal radiation and heat exchange within the arterial system. Additionally, the study explores the magnetic properties of the nanoparticles, investigating how they can be designed to bind to specific sites or clots within the artery. By applying an external magnetic field, these particles can be concentrated in desired locations, potentially enhancing treatment efficacy. Numerical analysis indicates that increasing the volume fraction of gold nanoparticles results in lower blood temperature and reduced blood velocity. The study also observes significant fluctuations in the thermal distribution profile, attributed to the influence of thermal radiation. The findings suggest that gold and silver nanoparticles, due to their distinctive properties, can improve blood flow and reduce the severity of stenosis. The research further highlights that enhancing the magnetic properties of these nanoparticles can enable them to target specific sites within the artery more effectively.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"471 ","pages":"Article 116723"},"PeriodicalIF":2.1,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144084439","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

Dynamics analysis of a discrete diffusion predator–prey model with prey refuge 具有猎物庇护的离散扩散捕食者-猎物模型动力学分析

IF 2.1 2区数学

Journal of Computational and Applied Mathematics Pub Date : 2025-04-18 DOI: 10.1016/j.cam.2025.116706

Xiongxiong Du, Xiaoling Han

引用次数: 0

A nodally bound-preserving finite element method for time-dependent convection–diffusion equations 时变对流扩散方程的节点保界有限元方法

IF 2.1 2区数学

Journal of Computational and Applied Mathematics Pub Date : 2025-04-17 DOI: 10.1016/j.cam.2025.116691

Abdolreza Amiri , Gabriel R. Barrenechea , Tristan Pryer

引用次数: 0

Sampling with derivatives in finitely generated shift-invariant spaces 有限生成平移不变空间中的导数抽样

IF 2.1 2区数学

Journal of Computational and Applied Mathematics Pub Date : 2025-04-17 DOI: 10.1016/j.cam.2025.116692

Kumari Priyanka, A. Antony Selvan

引用次数: 0

Fuzzy random multi-objective optimization using a novel mixed fuzzy random inverse DEA model in input-output production 基于混合模糊随机逆DEA模型的投入产出生产模糊随机多目标优化

IF 2.1 2区数学

Journal of Computational and Applied Mathematics Pub Date : 2025-04-15 DOI: 10.1016/j.cam.2025.116717

Lizhen Huang, Lei Chen

{"title":"Fuzzy random multi-objective optimization using a novel mixed fuzzy random inverse DEA model in input-output production","authors":"Lizhen Huang, Lei Chen","doi":"10.1016/j.cam.2025.116717","DOIUrl":"10.1016/j.cam.2025.116717","url":null,"abstract":"<div><div>Inverse data envelopment analysis (DEA), which is an effective tool for determining inputs and outputs, is commonly applied in areas such as output prediction, resource allocation, and target setting. However, existing inverse DEA methods typically assume precise and deterministic data, which limits applicability in uncertain production environments, particularly when both random and fuzzy environments are present. This study introduces a novel inverse DEA approach for optimizing inputs and outputs in mixed uncertainty environments. The proposed model allows decision-makers to achieve target efficiency and meet various input/output targets under different production scale assumptions. First, a new optimality principle for multi-objective fuzzy random problems is presented and the necessary theoretical conditions for input/output calculations are derived. Second, an equivalent linear model is introduced to solve the inverse DEA problem with fuzzy random variables, thereby overcoming the challenges associated with nonlinear programming. Notably, the proposed model offers enhanced flexibility as it does not rely on specific fuzzy numbers or predefined assumptions regarding random distributions. Finally, the effectiveness of the model is validated through numerical examples and a case study, demonstrating its practical application in complex decision-making scenarios.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"470 ","pages":"Article 116717"},"PeriodicalIF":2.1,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143851755","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