首页 > 最新文献

数学最新文献

英文 中文
IF:
Characterizations of solution sets of nonsmooth mathematical programming problems 非光滑数学规划问题解集的刻画
IF 2.6 2区 数学 Q1 MATHEMATICS, APPLIED Pub Date : 2026-10-01 Epub Date: 2026-02-10 DOI: 10.1016/j.cam.2026.117422
Shashi Kant Mishra , Dheerendra Singh
In this paper, we consider a nonsmooth mathematical programming problem and establish the characterization of solution sets. We also give a normal cone condition for nonsmooth mathematical programming problems to obtain optimality conditions using Lagrange multipliers and tangential subdifferentials. We also provide some examples in support of our results.
本文研究了一类非光滑数学规划问题,建立了解集的刻画。利用拉格朗日乘子和切向次微分,给出了非光滑数学规划问题的正锥条件,得到了最优性条件。我们还提供了一些例子来支持我们的结果。
{"title":"Characterizations of solution sets of nonsmooth mathematical programming problems","authors":"Shashi Kant Mishra ,&nbsp;Dheerendra Singh","doi":"10.1016/j.cam.2026.117422","DOIUrl":"10.1016/j.cam.2026.117422","url":null,"abstract":"<div><div>In this paper, we consider a nonsmooth mathematical programming problem and establish the characterization of solution sets. We also give a normal cone condition for nonsmooth mathematical programming problems to obtain optimality conditions using Lagrange multipliers and tangential subdifferentials. We also provide some examples in support of our results.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"484 ","pages":"Article 117422"},"PeriodicalIF":2.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387119","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
Regularization via generalized operational matrices: Theory and applications in machine learning classification 广义运算矩阵的正则化:机器学习分类的理论与应用
IF 2.6 2区 数学 Q1 MATHEMATICS, APPLIED Pub Date : 2026-10-01 Epub Date: 2026-02-19 DOI: 10.1016/j.cam.2026.117459
Saba Asgarzadeh , M.R. Eslahchi
In this research, we introduce new classes of regularization matrices constructed using generalized operational matrices of the Caputo fractional derivative. Experimental results confirm the performance and effectiveness of the proposed method. In another part of this study, the obtained matrices are applied to classification tasks in machine learning. The results demonstrate improved classification accuracy and more effective data representation.
在本研究中,我们引入了用Caputo分数阶导数的广义运算矩阵构造的一类新的正则化矩阵。实验结果验证了该方法的性能和有效性。在本研究的另一部分中,将得到的矩阵应用于机器学习中的分类任务。结果表明,该方法提高了分类精度和数据表示效率。
{"title":"Regularization via generalized operational matrices: Theory and applications in machine learning classification","authors":"Saba Asgarzadeh ,&nbsp;M.R. Eslahchi","doi":"10.1016/j.cam.2026.117459","DOIUrl":"10.1016/j.cam.2026.117459","url":null,"abstract":"<div><div>In this research, we introduce new classes of regularization matrices constructed using generalized operational matrices of the Caputo fractional derivative. Experimental results confirm the performance and effectiveness of the proposed method. In another part of this study, the obtained matrices are applied to classification tasks in machine learning. The results demonstrate improved classification accuracy and more effective data representation.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"484 ","pages":"Article 117459"},"PeriodicalIF":2.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387130","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
On the existence, uniqueness and regularity of solutions of micropolar fluid flow through porous medium in a curved pipe 微极流体在弯曲管中流过多孔介质解的存在性、唯一性和规律性
IF 1.8 3区 数学 Q1 MATHEMATICS, APPLIED Pub Date : 2026-10-01 Epub Date: 2026-02-04 DOI: 10.1016/j.nonrwa.2026.104616
A. Prabal, M. Devakar
In this paper, we present an analysis that establishes the existence and uniqueness of weak solution of the nonlinear system of partial differential equations governing the steady flow of an incompressible micropolar fluid flow through a homogeneous porous medium in a curved pipe. The Galerkin method along with a version of the Leray-Schauder principle has been used to prove the existence of a weak solution. It has been proved that there is a weak solution for sufficiently small values of curvature ratio (δ); furthermore, it has also been established that the solution is unique for sufficiently small values of Reynolds number (Re) and the micropolarity parameter (m). The regularity of the weak solution is also discussed in this paper; more importantly, if the cross-sectional area (Ω) is sufficiently smooth, specifically of class C3, then the weak solution becomes a classical solution.
本文给出了不可压缩微极流体在弯曲管内均匀多孔介质中稳定流动的非线性偏微分方程组弱解的存在唯一性分析。伽辽金方法连同勒雷-肖德原理的一个版本已经被用来证明弱解的存在。证明了曲率比(δ)值足够小时存在弱解;此外,还确定了当雷诺数(Re)和微极性参数(m)足够小时,该解是唯一的。本文还讨论了弱解的正则性;更重要的是,如果横截面积(Ω)足够光滑,特别是C3类,那么弱解就成为经典解。
{"title":"On the existence, uniqueness and regularity of solutions of micropolar fluid flow through porous medium in a curved pipe","authors":"A. Prabal,&nbsp;M. Devakar","doi":"10.1016/j.nonrwa.2026.104616","DOIUrl":"10.1016/j.nonrwa.2026.104616","url":null,"abstract":"<div><div>In this paper, we present an analysis that establishes the existence and uniqueness of weak solution of the nonlinear system of partial differential equations governing the steady flow of an incompressible micropolar fluid flow through a homogeneous porous medium in a curved pipe. The Galerkin method along with a version of the Leray-Schauder principle has been used to prove the existence of a weak solution. It has been proved that there is a weak solution for sufficiently small values of curvature ratio (<em>δ</em>); furthermore, it has also been established that the solution is unique for sufficiently small values of Reynolds number (<em>Re</em>) and the micropolarity parameter (<em>m</em>). The regularity of the weak solution is also discussed in this paper; more importantly, if the cross-sectional area (Ω) is sufficiently smooth, specifically of class <em>C</em><sup>3</sup>, then the weak solution becomes a classical solution.</div></div>","PeriodicalId":49745,"journal":{"name":"Nonlinear Analysis-Real World Applications","volume":"91 ","pages":"Article 104616"},"PeriodicalIF":1.8,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146188913","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
Long time behavior for a Lotka-Volterra competition diffusion system in periodic medium 周期介质中Lotka-Volterra竞争扩散系统的长时间行为
IF 1.8 3区 数学 Q1 MATHEMATICS, APPLIED Pub Date : 2026-10-01 Epub Date: 2025-12-24 DOI: 10.1016/j.nonrwa.2025.104560
Liyan Pang , Xiao Zhang
In this paper, the long time behavior for a two-species Lotka-Volterra reaction-diffusion system with strong competition in a periodic medium is concerned. We prove that under the compactly supported initial values, the solutions of Cauchy problem converge to a pair of diverging pulsating fronts. Further, we obtain a sufficient condition for solutions to converge to 1 with two different speeds to the left and right. Due to the spatial heterogeneity, the pulsating fronts depend on its direction and any pair of rightward and leftward wave speeds be asymmetrical. Therefore, our analysis mainly depends on constructing appropriate super- and subsolutions and using the comparison principle and asymptotic behavior of bistable pulsating fronts.
本文研究了周期介质中具有强竞争的两种Lotka-Volterra反应扩散系统的长时间行为。证明了在紧支持初值条件下,柯西问题的解收敛于一对发散的脉动锋。进一步,我们得到了解在左右两种不同速度下收敛于1的充分条件。由于脉动锋的空间非均质性,其方向与脉动锋有关,任意一对左右波速都是不对称的。因此,我们的分析主要依赖于构造合适的上解和子解,并利用双稳脉冲锋的比较原理和渐近特性。
{"title":"Long time behavior for a Lotka-Volterra competition diffusion system in periodic medium","authors":"Liyan Pang ,&nbsp;Xiao Zhang","doi":"10.1016/j.nonrwa.2025.104560","DOIUrl":"10.1016/j.nonrwa.2025.104560","url":null,"abstract":"<div><div>In this paper, the long time behavior for a two-species Lotka-Volterra reaction-diffusion system with strong competition in a periodic medium is concerned. We prove that under the compactly supported initial values, the solutions of Cauchy problem converge to a pair of diverging pulsating fronts. Further, we obtain a sufficient condition for solutions to converge to <strong><em>1</em></strong> with two different speeds to the left and right. Due to the spatial heterogeneity, the pulsating fronts depend on its direction and any pair of rightward and leftward wave speeds be asymmetrical. Therefore, our analysis mainly depends on constructing appropriate super- and subsolutions and using the comparison principle and asymptotic behavior of bistable pulsating fronts.</div></div>","PeriodicalId":49745,"journal":{"name":"Nonlinear Analysis-Real World Applications","volume":"91 ","pages":"Article 104560"},"PeriodicalIF":1.8,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841573","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
Remarks on the orbital stability for the sine-Gordon equation 关于正弦戈登方程的轨道稳定性的注释
IF 1.8 3区 数学 Q1 MATHEMATICS, APPLIED Pub Date : 2026-10-01 Epub Date: 2025-12-22 DOI: 10.1016/j.nonrwa.2025.104585
Fábio Natali
In this paper, we consider the problem of well-posedness and orbital stability of odd periodic traveling waves for the sine-Gordon equation. We first establish novel results concerning the local well-posedness in smoother periodic Sobolev spaces to guarantee the existence of a local time where the associated Cauchy problem has a unique solution with the zero mean property. Afterwards, we prove the orbital stability of odd periodic waves using a convenient index theorem applied to the constrained linearized operator defined in the Sobolev space with the zero mean property.
本文研究了正弦戈登方程奇周期行波的适定性和轨道稳定性问题。我们首先建立了关于更光滑周期Sobolev空间的局部适定性的新结果,以保证局部时间的存在,其中相关柯西问题具有具有零均值性质的唯一解。然后,我们利用一个方便的指数定理证明了奇周期波的轨道稳定性,该定理应用于在Sobolev空间中定义的具有零均值性质的约束线性化算子。
{"title":"Remarks on the orbital stability for the sine-Gordon equation","authors":"Fábio Natali","doi":"10.1016/j.nonrwa.2025.104585","DOIUrl":"10.1016/j.nonrwa.2025.104585","url":null,"abstract":"<div><div>In this paper, we consider the problem of well-posedness and orbital stability of odd periodic traveling waves for the sine-Gordon equation. We first establish novel results concerning the local well-posedness in smoother periodic Sobolev spaces to guarantee the existence of a local time where the associated Cauchy problem has a unique solution with the zero mean property. Afterwards, we prove the orbital stability of odd periodic waves using a convenient index theorem applied to the constrained linearized operator defined in the Sobolev space with the zero mean property.</div></div>","PeriodicalId":49745,"journal":{"name":"Nonlinear Analysis-Real World Applications","volume":"91 ","pages":"Article 104585"},"PeriodicalIF":1.8,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841568","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
A positivity-preserving subspace method based on neural networks for solving diffusion equations in the weak form 基于神经网络的保正子空间方法求解弱形式扩散方程
IF 2.6 2区 数学 Q1 MATHEMATICS, APPLIED Pub Date : 2026-10-01 Epub Date: 2026-02-12 DOI: 10.1016/j.cam.2026.117406
Pengyuan Liu , Zhaodong Xu , Zhiqiang Sheng
In this paper, we propose a positivity-preserving subspace method, termed PSNNW, which is based on neural networks formulated in the weak form for solving diffusion equations. The method employs a monotonic positivity-preserving nonlinear functions to transform the original equations into mathematically equivalent forms. The numerical solution of the transformed equation is subsequently computed using a subspace neural network method in the weak form designed for nonlinear problems. In this method, neural networks are employed to train and generate basis functions, which are then incorporated into iterative schemes, such as Picard iteration, to solve the problem within the Galerkin framework. Owing to the positivity-preserving transformation, the numerical solution of the original equation is guaranteed to remain positive. Numerical experiments demonstrate that the proposed method yields nonnegative solutions with high accuracy, confirming its simplicity and effectiveness in preserving positivity.
本文提出了一种基于弱形式神经网络的保正子空间方法PSNNW,用于求解扩散方程。该方法采用单调保正非线性函数将原方程转化为数学等价形式。然后利用针对非线性问题设计的弱形式的子空间神经网络方法计算变换后方程的数值解。该方法利用神经网络训练和生成基函数,并将基函数结合到Picard迭代等迭代方案中,在Galerkin框架内求解问题。由于进行了保正变换,保证了原方程的数值解为正。数值实验表明,该方法得到的非负解精度高,证明了该方法的简单性和保正性的有效性。
{"title":"A positivity-preserving subspace method based on neural networks for solving diffusion equations in the weak form","authors":"Pengyuan Liu ,&nbsp;Zhaodong Xu ,&nbsp;Zhiqiang Sheng","doi":"10.1016/j.cam.2026.117406","DOIUrl":"10.1016/j.cam.2026.117406","url":null,"abstract":"<div><div>In this paper, we propose a positivity-preserving subspace method, termed PSNNW, which is based on neural networks formulated in the weak form for solving diffusion equations. The method employs a monotonic positivity-preserving nonlinear functions to transform the original equations into mathematically equivalent forms. The numerical solution of the transformed equation is subsequently computed using a subspace neural network method in the weak form designed for nonlinear problems. In this method, neural networks are employed to train and generate basis functions, which are then incorporated into iterative schemes, such as Picard iteration, to solve the problem within the Galerkin framework. Owing to the positivity-preserving transformation, the numerical solution of the original equation is guaranteed to remain positive. Numerical experiments demonstrate that the proposed method yields nonnegative solutions with high accuracy, confirming its simplicity and effectiveness in preserving positivity.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"484 ","pages":"Article 117406"},"PeriodicalIF":2.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387180","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
Bound-preserving adaptive time-stepping methods with energy stability for simulating compressible gas flow in poroelastic media 具有能量稳定性的保界自适应时步法模拟孔隙弹性介质中可压缩气体流动
IF 2.6 2区 数学 Q1 MATHEMATICS, APPLIED Pub Date : 2026-10-01 Epub Date: 2026-02-28 DOI: 10.1016/j.cam.2026.117552
Huangxin Chen , Yuxiang Chen , Jisheng Kou , Shuyu Sun
In this paper, we present an efficient numerical method to address a thermodynamically consistent gas flow model in porous media involving compressible gas and deformable rock. The accurate modeling of gas flow in porous media often poses significant challenges due to their inherent nonlinearity, the coupling between gas and rock dynamics, and the need to preserve physical principles such as mass conservation, energy dissipation and molar density boundedness. The system is further complicated by the need to balance computational efficiency with the accuracy and stability of the numerical scheme. To tackle these challenges, we adopt a stabilization approach that is able to preserve the original energy dissipation while achieving linear energy-stable numerical schemes. We also prove the convergence of the adopted linear iterative method. At each time step, the stabilization parameter is adaptively updated using a simple and explicit formula to ensure compliance with the original energy dissipation law. The proposed method uses adaptive time stepping to improve computational efficiency while maintaining solution accuracy and boundedness. The adaptive time step size is calculated explicitly at each iteration, ensuring stability and allowing for efficient handling of highly dynamic scenarios. A mixed finite element method combined with an upwind scheme is employed as spatial discretization to ensure mass conservation and stability. Finally, we conduct a series of numerical experiments to validate the performance and robustness of the proposed numerical method.
在本文中,我们提出了一种有效的数值方法来处理涉及可压缩气体和可变形岩石的多孔介质中热力学一致的气体流动模型。由于多孔介质固有的非线性、气体和岩石动力学之间的耦合以及需要保持质量守恒、能量耗散和摩尔密度有界等物理原理,对多孔介质中气体流动的精确建模常常面临重大挑战。由于需要平衡计算效率与数值格式的准确性和稳定性,系统进一步复杂化。为了应对这些挑战,我们采用了一种稳定方法,能够在保持原始能量耗散的同时实现线性能量稳定的数值格式。并证明了所采用的线性迭代方法的收敛性。在每个时间步长,采用简单明了的公式自适应地更新稳定化参数,以保证符合原能量耗散规律。该方法采用自适应时间步进,在保证求解精度和有界性的同时提高了计算效率。自适应时间步长是在每次迭代中明确计算的,确保了稳定性,并允许有效地处理高度动态的场景。采用混合有限元法结合迎风方案进行空间离散,以保证质量守恒和稳定性。最后,我们进行了一系列的数值实验来验证所提出的数值方法的性能和鲁棒性。
{"title":"Bound-preserving adaptive time-stepping methods with energy stability for simulating compressible gas flow in poroelastic media","authors":"Huangxin Chen ,&nbsp;Yuxiang Chen ,&nbsp;Jisheng Kou ,&nbsp;Shuyu Sun","doi":"10.1016/j.cam.2026.117552","DOIUrl":"10.1016/j.cam.2026.117552","url":null,"abstract":"<div><div>In this paper, we present an efficient numerical method to address a thermodynamically consistent gas flow model in porous media involving compressible gas and deformable rock. The accurate modeling of gas flow in porous media often poses significant challenges due to their inherent nonlinearity, the coupling between gas and rock dynamics, and the need to preserve physical principles such as mass conservation, energy dissipation and molar density boundedness. The system is further complicated by the need to balance computational efficiency with the accuracy and stability of the numerical scheme. To tackle these challenges, we adopt a stabilization approach that is able to preserve the original energy dissipation while achieving linear energy-stable numerical schemes. We also prove the convergence of the adopted linear iterative method. At each time step, the stabilization parameter is adaptively updated using a simple and explicit formula to ensure compliance with the original energy dissipation law. The proposed method uses adaptive time stepping to improve computational efficiency while maintaining solution accuracy and boundedness. The adaptive time step size is calculated explicitly at each iteration, ensuring stability and allowing for efficient handling of highly dynamic scenarios. A mixed finite element method combined with an upwind scheme is employed as spatial discretization to ensure mass conservation and stability. Finally, we conduct a series of numerical experiments to validate the performance and robustness of the proposed numerical method.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"484 ","pages":"Article 117552"},"PeriodicalIF":2.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386633","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 new C1-continuous variational integration scheme for mechanical systems subjected to acceleration-dependent forces 一个新的c1 -连续变分积分方案的机械系统受到加速度相关的力
IF 2.6 2区 数学 Q1 MATHEMATICS, APPLIED Pub Date : 2026-10-01 Epub Date: 2026-02-24 DOI: 10.1016/j.cam.2026.117509
Ping Zhou , Songhan Zhang , Hui Ren , Zheng Chen , Wei Fan
The C1-continuity of calculated state curves is crucial for engineering problems subject to acceleration-dependent forces, such as hydrodynamic loads and control forces. Conventional variational integration schemes with prominent energy and momentum preserving properties are favored to calculate the dynamics of mechanical systems, however, can sometimes lose their efficacy due to a lack of continuity. In this work, a novel C1-continuous variational integration scheme is developed within a simple and general construction framework, ensuring the continuity of the generalized coordinates and their first derivative at the discrete-time points. This scheme is constructed by approximating generalized coordinates and velocities using Hermite polynomials within a certain time span with the action integral computed numerically. This framework greatly simplifies the derivation and implementation by avoiding the summation of discrete node variations, and it is also suitable for constructing other variational schemes based on Lagrangian polynomials of various orders. The algorithmic characteristics, including stability, dissipation, period elongation, and convergence order, are theoretically analyzed. The momentum-preserving and nearly energy-preserving properties are numerically demonstrated. Moreover, practical engineering problems subject to acceleration-dependent forces are investigated, which have well confirmed the feasibility of the proposed C1-continuous variational scheme in practical dynamic analyses.
计算状态曲线的c1 -连续性对于受加速度相关力(如流体动力载荷和控制力)影响的工程问题至关重要。传统的变分积分方案具有突出的能量和动量保持特性,有利于计算机械系统的动力学,但有时会由于缺乏连续性而失去其有效性。本文提出了一种新颖的c1 -连续变分积分方案,该方案在一个简单和通用的构造框架内,保证了广义坐标及其一阶导数在离散时间点上的连续性。该方案是在一定时间范围内用Hermite多项式逼近广义坐标和速度,并通过数值计算得到作用积分来构造的。该框架避免了离散节点变化的求和,大大简化了推导和实现,也适用于构造其他基于不同阶次拉格朗日多项式的变分格式。从理论上分析了算法的稳定性、耗散、周期延长和收敛顺序等特性。数值证明了其保持动量和几乎保持能量的性质。此外,研究了受加速度相关力影响的实际工程问题,很好地证实了c1 -连续变分格式在实际动力分析中的可行性。
{"title":"A new C1-continuous variational integration scheme for mechanical systems subjected to acceleration-dependent forces","authors":"Ping Zhou ,&nbsp;Songhan Zhang ,&nbsp;Hui Ren ,&nbsp;Zheng Chen ,&nbsp;Wei Fan","doi":"10.1016/j.cam.2026.117509","DOIUrl":"10.1016/j.cam.2026.117509","url":null,"abstract":"<div><div>The C<sup>1</sup>-continuity of calculated state curves is crucial for engineering problems subject to acceleration-dependent forces, such as hydrodynamic loads and control forces. Conventional variational integration schemes with prominent energy and momentum preserving properties are favored to calculate the dynamics of mechanical systems, however, can sometimes lose their efficacy due to a lack of continuity. In this work, a novel C<sup>1</sup>-continuous variational integration scheme is developed within a simple and general construction framework, ensuring the continuity of the generalized coordinates and their first derivative at the discrete-time points. This scheme is constructed by approximating generalized coordinates and velocities using Hermite polynomials within a certain time span with the action integral computed numerically. This framework greatly simplifies the derivation and implementation by avoiding the summation of discrete node variations, and it is also suitable for constructing other variational schemes based on Lagrangian polynomials of various orders. The algorithmic characteristics, including stability, dissipation, period elongation, and convergence order, are theoretically analyzed. The momentum-preserving and nearly energy-preserving properties are numerically demonstrated. Moreover, practical engineering problems subject to acceleration-dependent forces are investigated, which have well confirmed the feasibility of the proposed C<sup>1</sup>-continuous variational scheme in practical dynamic analyses.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"484 ","pages":"Article 117509"},"PeriodicalIF":2.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386987","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
Higher-order multiscale finite element method for linear elasticity equations with oscillating coefficients 具有振荡系数的线性弹性方程的高阶多尺度有限元法
IF 2.6 2区 数学 Q1 MATHEMATICS, APPLIED Pub Date : 2026-10-01 Epub Date: 2026-02-23 DOI: 10.1016/j.cam.2026.117457
Yanfang Yang, Lu Xiao
In this paper, we study higher-order Multiscale Finite Element Method (MsFEM) to solve linear elasticity equations with oscillating coefficients. Compared to the Finite Element Method (FEM), MsFEM can obtain the characteristics of fine scale in coarse mesh by using carefully designed multiscale basis functions. By using higher-order basis functions, better accuracy can be achieved. To further improve accuracy, several techniques are considered: oversampling methods and oscillatory boundary conditions (OBCs) are used to prevent the influence of boundary conditions on the construction of multiscale basis functions; the Petrov-Galerkin method, with the trial functions being multiscale basis functions and the test functions being polynomial functions. Numerical examples are presented to demonstrate the efficiency of the proposed methods.
本文研究了用高阶多尺度有限元法求解具有振荡系数的线性弹性方程。与有限元法(FEM)相比,MsFEM通过精心设计多尺度基函数,可以在粗网格中获得细尺度特征。采用高阶基函数可以获得更好的精度。为了进一步提高精度,考虑了几种技术:使用过采样方法和振荡边界条件(OBCs)来防止边界条件对多尺度基函数构造的影响;Petrov-Galerkin方法,试函数为多尺度基函数,试函数为多项式函数。数值算例验证了所提方法的有效性。
{"title":"Higher-order multiscale finite element method for linear elasticity equations with oscillating coefficients","authors":"Yanfang Yang,&nbsp;Lu Xiao","doi":"10.1016/j.cam.2026.117457","DOIUrl":"10.1016/j.cam.2026.117457","url":null,"abstract":"<div><div>In this paper, we study higher-order Multiscale Finite Element Method (MsFEM) to solve linear elasticity equations with oscillating coefficients. Compared to the Finite Element Method (FEM), MsFEM can obtain the characteristics of fine scale in coarse mesh by using carefully designed multiscale basis functions. By using higher-order basis functions, better accuracy can be achieved. To further improve accuracy, several techniques are considered: oversampling methods and oscillatory boundary conditions (OBCs) are used to prevent the influence of boundary conditions on the construction of multiscale basis functions; the Petrov-Galerkin method, with the trial functions being multiscale basis functions and the test functions being polynomial functions. Numerical examples are presented to demonstrate the efficiency of the proposed methods.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"484 ","pages":"Article 117457"},"PeriodicalIF":2.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386989","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
Applying fixed point techniques for solving tripled system of quantum integral equations with numerical results 应用不动点技术求解三次量子积分方程组并给出数值结果
IF 2.6 2区 数学 Q1 MATHEMATICS, APPLIED Pub Date : 2026-10-01 Epub Date: 2026-02-24 DOI: 10.1016/j.cam.2026.117542
Hasanen A. Hammad , Tarek Aboelenen
This study investigates the demanding problem of proving the existence of solutions for a tripled system that couples quantum integral equations with quadratic integral equations. To tackle the intrinsic nonlinear and noncompact features of the model, we employ Petryshyn’s fixed-point theorem, a significant generalization of Darbo’s theorem formulated within the framework of measures of noncompactness. Based on this approach, we derive rigorous and verifiable existence conditions applicable to a broad class of quantum integral systems. The theoretical findings are supported by a comprehensive illustrative example that confirms the validity of the proposed criteria. In addition, we develop a constructive collocation method founded on barycentric interpolation and Jackson quadrature for q-integrals, and we verify the required assumptions within the same example. Numerical experiments are finally presented to confirm the practical applicability of the existence results and to demonstrate the accuracy, stability, and robustness of the proposed discretization scheme.
本文研究了量子积分方程与二次积分方程耦合的三重系统解的存在性证明问题。为了解决模型固有的非线性和非紧性特征,我们采用了Petryshyn的不动点定理,这是在非紧性测度框架内表述的Darbo定理的一个重要推广。在此基础上,我们导出了适用于广义量子积分系统的严格且可验证的存在性条件。理论发现得到了一个全面的说明性例子的支持,该例子证实了所提出标准的有效性。此外,我们开发了一种基于质心插值和Jackson正交的q积分建设性配置方法,并在同一例子中验证了所需的假设。最后通过数值实验验证了存在结果的实际适用性,并验证了所提出的离散化方案的准确性、稳定性和鲁棒性。
{"title":"Applying fixed point techniques for solving tripled system of quantum integral equations with numerical results","authors":"Hasanen A. Hammad ,&nbsp;Tarek Aboelenen","doi":"10.1016/j.cam.2026.117542","DOIUrl":"10.1016/j.cam.2026.117542","url":null,"abstract":"<div><div>This study investigates the demanding problem of proving the existence of solutions for a tripled system that couples quantum integral equations with quadratic integral equations. To tackle the intrinsic nonlinear and noncompact features of the model, we employ Petryshyn’s fixed-point theorem, a significant generalization of Darbo’s theorem formulated within the framework of measures of noncompactness. Based on this approach, we derive rigorous and verifiable existence conditions applicable to a broad class of quantum integral systems. The theoretical findings are supported by a comprehensive illustrative example that confirms the validity of the proposed criteria. In addition, we develop a constructive collocation method founded on barycentric interpolation and Jackson quadrature for q-integrals, and we verify the required assumptions within the same example. Numerical experiments are finally presented to confirm the practical applicability of the existence results and to demonstrate the accuracy, stability, and robustness of the proposed discretization scheme.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"484 ","pages":"Article 117542"},"PeriodicalIF":2.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386995","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
期刊
全部 Dokl. Math. Funct. Anal. Appl. J. Homotopy Relat. Struct. J. Math. Fluid Mech. Math. Phys. Anal. Geom. ACTA MATH APPL SIN-E Adv. Nonlinear Stud. Adv. Appl. Clifford Algebras ADV GEOM ALGEBR LOG+ Am. J. Math. Am. Math. Mon. ANN I H POINCARE-PR APPL CATEGOR STRUCT ANN STAT ANN MATH Appl. Numer. Math. Ann. Mat. Pura Appl. Ann. Global Anal. Geom. Arch. Math. Archiv. Math. Logic BIOMETRICS BIOMETRIKA Bull. Math. Sci Bull. Math. Biol. B IRAN MATH SOC Calc. Var. Partial Differ. Equations Bull. Am. Math. Soc. CALCOLO CHAOS SOLITON FRACT CHAOS COMB PROBAB COMPUT COMMUN STAT-THEOR M Commun. Math. Stat. Commun. Pure Appl. Math. C.R. Math. Commun. Pure Appl. Anal. Demonstratio Mathematica Des. Codes Cryptogr. Duke Math. J. Electron. J. Comb. FILOMAT FORUM MATH Fractal and Fractional Geom. Funct. Anal. GRAPH COMBINATOR INTEGR EQUAT OPER TH INT J ALGEBR COMPUT Interfaces Free Boundaries Int. J. Comput. Math. INT J NUMBER THEORY INVENT MATH Int. Math. Res. Not. Int. Stat. Rev. Isr. J. Math. J. Algebra J ALGEBR COMB J. Appl. Math. Comput. J. Appl. Stat. J. Comb. Des. J. Comput. Graphical Stat. J. Complex Networks J. Differ. Equations Appl. J. Differ. Equations J. Dyn. Differ. Equations J. Differ. Geom. J. Funct. Anal. J. Funct. Spaces J. Global Optim. J.Fourier Anal. Appl. J. Graph Theory J. Inequal. Appl. J. Math. Imaging Vision J. Multivar. Anal. J. Symb. Log. Journal of Survey Statistics and Methodology J. Am. Stat. Assoc. Linear Algebra Appl. Math. Z. MATH SLOVACA Math. Modell. Nat. Phenom. Math. Notes Math. Program. MATHEMATICS-BASEL Math. Ann. Math. Proc. Cambridge Philos. Soc. METHODOL COMPUT APPL Math. Comput. MATHEMATIKA Numer. Methods Partial Differ. Equations PHYSICA D Probab. Theory Relat. Fields Proc. Edinburgh Math. Soc. Proc. Am. Math. Soc. Q. Appl. Math. Ric. Mat. Stochastic Models STAT COMPUT TAIWAN J MATH TOPOL METHOD NONL AN
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:604180095
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1