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An efficient matrix free optimization algorithm combining a revised PRP and FR-CG type methods with application to robotics 结合改进的PRP和FR-CG型方法的一种有效的无矩阵优化算法及其在机器人中的应用
IF 2.6 2区 数学 Q1 MATHEMATICS, APPLIED Pub Date : 2026-01-23 DOI: 10.1016/j.cam.2026.117378
Nasiru Salihu , Poom Kumam , Aliyu Muhammed Awwal , Mathew Remilekun Odekunle , Thidaporn Seangwattana
Many problems arise from science and engineering which can be expressed as an unconstrained minimization problem. Therefore, developing numerical methods to obtain their approximate solutions has become necessary, as their exact solutions cannot be obtained. Several such numerical methods have been proposed, with the conjugate gradient (CG) method stands out to be more efficient in handling this type of problem, due to its nice theoretical structure and promising numerical result. In this article, we consider a CG algorithm based on a generalized conjugacy condition. The new CG parameter is selected to ensure a convex combination of modified version of the Polak, Ribière-Polyak (PRP) and Fletcher-Revees (FR) CG algorithms. The numerical implementation adopts inexact line search which revealed that the scheme is robust when compared with some known efficient algorithms in literature. Furthermore, the theoretical analysis shows that the proposed method converge globally. The method is also applicable to solve three degree of freedom motion control robotic model.
科学和工程中出现的许多问题都可以表示为无约束最小化问题。因此,发展数值方法来获得它们的近似解是必要的,因为它们的精确解不能得到。目前已经提出了几种这样的数值方法,其中共轭梯度法(CG)由于其良好的理论结构和令人满意的数值结果,在处理这类问题时更为有效。在本文中,我们考虑了一种基于广义共轭条件的CG算法。选择新的CG参数是为了确保Polak、ribire - polyak (PRP)和Fletcher-Revees (FR) CG算法的改进版本的凸组合。数值实现采用非精确直线搜索,与文献中已知的一些高效算法相比,该算法具有较强的鲁棒性。理论分析表明,该方法具有全局收敛性。该方法同样适用于求解三自由度运动控制机器人模型。
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引用次数: 0
Efficient matrix-based quadrature rules for oscillatory integrals with products of two Bessel functions 含两个贝塞尔函数积的振荡积分的有效的基于矩阵的求积分规则
IF 2.6 2区 数学 Q1 MATHEMATICS, APPLIED Pub Date : 2026-01-22 DOI: 10.1016/j.cam.2026.117377
Ruyun Chen, Hong Du
This work develops two matrix-based quadrature rules to compute the integrals containing products of two Bessel functions. By reformulating these integrals into a matrix framework and employing low-order derivatives of Bessel functions of the first kind in combination with integration by parts, we construct both a matrix-based asymptotic rule and a matrix-based Filon-type rule. Numerical experiments confirm the theoretical analysis and highlight the efficiency of the proposed rules.
本文发展了两个基于矩阵的积分规则来计算包含两个贝塞尔函数积的积分。通过将这些积分形式转化为矩阵框架,并利用第一类贝塞尔函数的低阶导数与分部积分相结合,构造了基于矩阵的渐近规则和基于矩阵的filon型规则。数值实验验证了理论分析,并突出了所提规则的有效性。
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引用次数: 0
Fröbenius expansions for second-order random differential equations: Stochastic analysis and applications to Lindley-type damping models Fröbenius二阶随机微分方程的展开式:随机分析和林德利型阻尼模型的应用
IF 2.6 2区 数学 Q1 MATHEMATICS, APPLIED Pub Date : 2026-01-22 DOI: 10.1016/j.cam.2026.117379
Halim Zeghdoudi , Mohamed Amine Kerker , Elif Boduroglu
This paper develops a Frobenius series framework for the stochastic analysis of second–order random differential equations of the formY¨(t)+A(t)Y˙(t)=0,where the damping coefficient A(t) is a positive stochastic process and the initial conditions are square–integrable random variables. Assuming mean–square analyticity of A(t) in a neighborhood of the initial time, we establish existence and uniqueness of the solution in L2(Ω) and derive exponentially convergent truncation error bounds for the associated Frobenius expansion. The resulting series representation enables the numerical approximation of the probability density function of Y(t) via Monte Carlo simulation. To improve computational efficiency, a control variates strategy is incorporated for variance reduction.
A comprehensive numerical study is conducted for a broad family of positive, right–skewed damping distributions, including the Lindley, XLindley, New XLindley (NXLD), Gamma–Lindley, Inverse–Lindley, Truncated–Lindley, Log–Lindley, and a newly proposed Mixed Lindley–Uniform model. The simulations illustrate how different tail behaviors and boundedness properties of the damping coefficient influence the stochastic dynamics and the accuracy of density estimation. Finally, stylized applications to option pricing and Value–at–Risk estimation are presented to illustrate how the Frobenius–based framework and control variates methodology can be embedded within standard uncertainty quantification workflows. Overall, the proposed approach provides a flexible and computationally efficient tool for the analysis of randomly damped dynamical systems.
本文建立了一类二阶随机微分方程(my¨(t)+ a (t)Y˙(t)=0)随机分析的Frobenius级数框架,其中阻尼系数a (t)是一个正随机过程,初始条件是平方可积随机变量。假设A(t)在初始时间的邻域具有均方分析性,我们建立了该解在L2(Ω)上的存在唯一性,并推导出相应的Frobenius展开式的指数收敛截断误差界。所得到的序列表示可以通过蒙特卡罗模拟对Y(t)的概率密度函数进行数值逼近。为了提高计算效率,采用控制变量策略减小方差。本文对一系列正的、右偏的阻尼分布进行了全面的数值研究,包括Lindley、XLindley、New XLindley (NXLD)、Gamma-Lindley、Inverse-Lindley、trunted - Lindley、Log-Lindley以及新提出的Mixed Lindley - uniform模型。仿真结果说明了阻尼系数的不同尾态和有界性对随机动力学和密度估计精度的影响。最后,介绍了期权定价和风险价值估计的程式化应用,以说明如何将基于frobenius的框架和控制变量方法嵌入到标准的不确定性量化工作流程中。总的来说,所提出的方法为随机阻尼动力系统的分析提供了一种灵活且计算效率高的工具。
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引用次数: 0
Spline quasi-interpolating and quasi2-interpolating projectors for the numerical solution of Cauchy singular integral equations 柯西奇异积分方程数值解的样条拟插值和拟2插值投影
IF 2.6 2区 数学 Q1 MATHEMATICS, APPLIED Pub Date : 2026-01-21 DOI: 10.1016/j.cam.2026.117376
Alessandra Aimi , Mattia Alex Leoni , Sara Remogna
The paper deals with the numerical solution of Cauchy singular integral equations, by means of spline quasi interpolating projectors and their variant quasi2-interpolating projectors, within a collocation approach which takes into account the particular features of the problem at hand. Several numerical results, including those related to the application of the presented approach to an extended model problem, validate the proposed error estimates.
本文利用样条拟插值投影和它们的变型拟2-插值投影,考虑到问题的特殊性,用配点法研究了柯西奇异积分方程的数值解。几个数值结果,包括与所提出的方法应用于扩展模型问题有关的结果,验证了所提出的误差估计。
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引用次数: 0
Novel Birkhoff-hermite ERKN methods for solving general second-order highly oscillatory systems 求解一般二阶高振荡系统的Birkhoff-hermite ERKN新方法
IF 2.6 2区 数学 Q1 MATHEMATICS, APPLIED Pub Date : 2026-01-21 DOI: 10.1016/j.cam.2026.117375
Yonglei Fang , Changying Liu , Xiong You
This paper is devoted to the effective integration of general second-order highly oscillatory systems. By approximating the nonlinear integrals appeared in the matrix-variation-of-constants formula with the Birkhoff-Hermite interpolating polynomial, new ERKN integrators (BHERKN) are obtained. The symmetry and nonlinear stability of the BHERKN integrators are analyzed. By energy analysis, the BHERKN integrators are shown to converge with an arbitrary high-order. Finally, numerical experiments are reported to show the high efficiency, accuracy and robustness of our new methods.
研究一般二阶高振荡系统的有效积分问题。用Birkhoff-Hermite插值多项式逼近矩阵-常数变分公式中的非线性积分,得到新的ERKN积分器(BHERKN)。分析了BHERKN积分器的对称性和非线性稳定性。通过能量分析,证明了BHERKN积分器具有任意高阶收敛性。最后,通过数值实验验证了该方法的有效性、准确性和鲁棒性。
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引用次数: 0
Low tubal-rank tensor recovery with adversarial sparse noises 具有对抗稀疏噪声的低管阶张量恢复
IF 2.6 2区 数学 Q1 MATHEMATICS, APPLIED Pub Date : 2026-01-20 DOI: 10.1016/j.cam.2026.117373
Wenfei Cao , Xicui Peng , Yang Chen , Jiahui Ji
In this paper, we study the tensor recovery problem from linear measurements corrupted by the ℓ1-bounded noise plus the adversarial noise with sparsity ratio ω. To handle this problem, we propose a novel least-absolute-deviation (LAD) loss minimization model based on low tubal-rank tensor decomposition. For the requirement of theoretical studies, we extend the mixed ℓ1/ℓ2-RIP and the ω-robustness to the tensor case, i.e., ℓ1/ℓ2-t-RIP and ω-t-robustness. Then leveraging these tools, we establish a reliable recovery guarantee for the proposed model, showing that when the sampling complexity reaches O((n1+n2+1)n3r), the model’s optimal solution can robustly recover the original low tubal-rank tensor for any ω < 0.239. Moreover, we develop a subgradient descent algorithm to solve the proposed model and prove that it achieves geometrical convergence under appropriate initialization conditions. Finally, extensive experiments on the synthetic tensors and real video datasets are conducted to validate the exactness of the established theories and demonstrate the effectiveness of the proposed approach.
本文研究了被l1有界噪声和稀疏度比为ω的对抗噪声破坏的线性测量的张量恢复问题。为了解决这一问题,我们提出了一种基于低管阶张量分解的最小绝对偏差(LAD)损失最小化模型。为了理论研究的需要,我们将混合的1/ 2-RIP和ω-鲁棒性推广到张量情况,即1/ 2-t-RIP和ω-t-鲁棒性。然后利用这些工具,我们为所提出的模型建立了可靠的恢复保证,表明当采样复杂度达到O((n1+n2+1)n3r)时,模型的最优解可以鲁棒恢复任意ω <; 0.239的原始低管阶张量。此外,我们开发了一种亚梯度下降算法来求解所提出的模型,并证明了该算法在适当的初始化条件下可以实现几何收敛。最后,在合成张量和真实视频数据集上进行了大量实验,验证了所建立理论的准确性,并证明了所提出方法的有效性。
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引用次数: 0
Instabilities and pattern formation in fractional incommensurate activator-inhibitor reaction-diffusion systems 分数阶不相称活化剂-抑制剂反应-扩散体系的不稳定性和模式形成
IF 2.6 2区 数学 Q1 MATHEMATICS, APPLIED Pub Date : 2026-01-20 DOI: 10.1016/j.cam.2026.117374
Bohdan Datsko , Vasyl Gafiychuk
Different types of instability and resulting pattern formation in a two-component incommensurate fractional reaction-diffusion system are studied. Considered system sets the possibility of continuous transitions between classical systems with integer derivatives. As a result, the presented investigations provide a better understanding of the instability conditions and nonlinear solutions not only in systems with fractional-order derivatives but also in classical two-component elliptic, parabolic, and hyperbolic systems, as well as those of a mixed type. Based on the linear stability analysis, the computer simulation of nonlinear dynamics in the fractional two-component system with cubic-like nonlinearity has been performed, demonstrating the rich diversity of pattern formation phenomena.
研究了双组分不相称分数反应扩散体系中不同类型的不稳定性及其形成的模式。被考虑的系统设置了具有整数导数的经典系统之间连续转换的可能性。因此,本文的研究不仅对分数阶导数系统的不稳定性条件和非线性解提供了更好的理解,而且对经典的双分量椭圆型、抛物型和双曲型系统以及混合型系统的不稳定性条件和非线性解也提供了更好的理解。在线性稳定性分析的基础上,对具有三次非线性的分数双组分系统进行了非线性动力学的计算机模拟,证明了其模式形成现象的丰富多样性。
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引用次数: 0
An efficient Tau approach for solving a class of third-kind Volterra integral equations with proportional delays 求解一类具有比例时滞的第三类Volterra积分方程的有效Tau方法
IF 2.6 2区 数学 Q1 MATHEMATICS, APPLIED Pub Date : 2026-01-19 DOI: 10.1016/j.cam.2026.117370
E. Aourir , H. Laeli Dastjerdi , M. Oudani
This work presents a new algorithm for solving a kind of Volterra delay integral equations of the third kind (VDIEs). Using the Tau method and generalized polynomial bases, our developed method is a robust approach for solving these equations. Specifically, we employ simple matrix operations to enhance the Tau approach. The underlying strategy leverages orthogonal polynomial bases to change the original equation into a matrix-vector form. Such a transformation makes the third-kind VDIEs easier to handle by turning them into a set of algebraic equations. Importantly, this method exhibits good stability, reduces memory usage, and is computationally cost-effective. The paper details the algorithm’s formulation and shows its capability to provide approximate polynomial solutions. We perform a thorough error estimation to check the method’s accuracy. To demonstrate its practical effectiveness, we use several numerical examples. The obtained results highlight the performance of the method and prove its alignment with theoretical error predictions. Furthermore, a comparative analysis with analytical solutions and alternative methods reaffirms the efficiency of the developed approach.
本文提出了求解一类第三类Volterra延迟积分方程的新算法。利用Tau方法和广义多项式基,我们开发的方法是求解这些方程的一种鲁棒方法。具体来说,我们使用简单的矩阵运算来增强Tau方法。该策略利用正交多项式基将原始方程转换为矩阵-向量形式。这种转换通过将第三类vdi转化为一组代数方程,使其更易于处理。重要的是,该方法具有良好的稳定性,减少了内存使用,并且在计算上具有成本效益。本文详细介绍了该算法的公式,并展示了其提供近似多项式解的能力。我们进行了彻底的误差估计,以检查该方法的准确性。为了证明其实际有效性,我们使用了几个数值算例。得到的结果突出了该方法的性能,并证明了其与理论误差预测的一致性。此外,与解析解和替代方法的比较分析重申了所开发方法的有效性。
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引用次数: 0
Arc spline approximation of envelopes of evolving planar domains 演化平面域包络的弧样条逼近
IF 2.6 2区 数学 Q1 MATHEMATICS, APPLIED Pub Date : 2026-01-18 DOI: 10.1016/j.cam.2026.117372
Jana Vráblíková, Bert Jüttler
Computing the envelope of deforming planar domains is a significant and challenging problem with a wide range of potential applications. We approximate the envelope using circular arc splines, curves that balance geometric flexibility and computational simplicity. Our approach combines two concepts to achieve these benefits.
First, we represent a planar domain by its medial axis transform (MAT), which is a geometric graph in Minkowski space R2,1 (possibly with degenerate branches). We observe that circular arcs in the Minkowski space correspond to MATs of arc spline domains. Furthermore, as a planar domain evolves over time, each branch of its MAT evolves and forms a surface in the Minkowski space. This allows us to reformulate the problem of envelope computation as a problem of computing cyclographic images of finite sets of curves on these surfaces. We propose and compare two pairs of methods for approximating the curves and boundaries of their cyclographic images. All of these methods result in an arc spline approximation of the envelope of the evolving domain.
Second, we exploit the geometric flexibility of circular arcs in both the plane and Minkowski space to achieve a high approximation rate. The computational simplicity ensures the efficient trimming of redundant branches of the generated envelope using a sweep line algorithm with optimal computational complexity.
计算变形平面域的包络是一个具有广泛潜在应用前景的重要而具有挑战性的问题。我们使用圆弧样条近似包络线,平衡几何灵活性和计算简单性的曲线。我们的方法结合了两个概念来实现这些好处。首先,我们用平面域的中轴变换(MAT)表示平面域,该平面域是Minkowski空间R2,1中的一个几何图(可能有简并分支)。我们观察到Minkowski空间中的圆弧对应于弧样条域的MATs。此外,随着时间的推移,平面域的每个分支都在闵可夫斯基空间中演变并形成一个表面。这允许我们将包络计算问题重新表述为计算这些表面上有限曲线集的环形图像的问题。我们提出并比较了两对近似其环形图像的曲线和边界的方法。所有这些方法的结果都是演化域包络线的弧样条近似。其次,我们利用圆弧在平面和闵可夫斯基空间中的几何灵活性来实现高近似率。计算的简单性保证了用最优计算复杂度的扫描线算法对生成包络线的冗余分支进行有效修剪。
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引用次数: 0
On the randomized Euler scheme for stochastic differential equations with integral-form drift 具有积分型漂移的随机微分方程的随机欧拉格式
IF 2.6 2区 数学 Q1 MATHEMATICS, APPLIED Pub Date : 2026-01-18 DOI: 10.1016/j.cam.2026.117367
Paweł Przybyłowicz, Michał Sobieraj
In this paper, we investigate the problem of strong approximation of the solutions of stochastic differential equations (SDEs) when the drift coefficient is given in integral form. We investigate its upper error bounds, in terms of the discretization parameter n and the size M of the random sample drawn at each step of the algorithm, in different subclasses of coefficients of the underlying SDE presenting various rates of convergence. Integral-form drift often appears when analyzing stochastic dynamics of optimization procedures in machine learning (ML) problems. Hence, we additionally discuss connections of the defined randomized Euler approximation scheme with the perturbed version of the stochastic gradient descent (SGD) algorithm. Finally, the results of numerical experiments performed using GPU architecture are also reported, including a comparison with other popular optimizers used in ML.
本文研究了当漂移系数以积分形式给出时随机微分方程解的强逼近问题。我们根据离散化参数n和算法每一步绘制的随机样本的大小M,在具有不同收敛速度的底层SDE系数的不同子类中研究其上误差界。在分析机器学习问题中优化过程的随机动力学时,常出现积分漂移。因此,我们进一步讨论了已定义的随机欧拉近似格式与随机梯度下降(SGD)算法的扰动版本之间的联系。最后,还报告了使用GPU架构进行的数值实验结果,包括与ML中使用的其他流行优化器的比较。
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引用次数: 0
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Journal of Computational and Applied Mathematics
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