Journal of Computational and Applied Mathematics最新文献

{"title":"A Shepard-like Hermite interpolation operator with fourth approximation order","authors":"Domingo Barrera ,&nbsp;Otheman Nouisser ,&nbsp;Benaissa Zerroudi","doi":"10.1016/j.cam.2025.117158","DOIUrl":"10.1016/j.cam.2025.117158","url":null,"abstract":"<div><div>From a first order Hermite interpolant on a triangle written in terms of barycentric coordinates, a Shepard-like interpolation is defined. It achieves fourth order of approximation. Its performance is checked by considering well-known test functions as well different Delaunay triangulations. The novel operator is compared to a Shepard-type operator and to a Hermite cubic interpolant over a Powell–Sabin partition.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"477 ","pages":"Article 117158"},"PeriodicalIF":2.6,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145326263","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 low-complexity algorithm to digitally uncouple the mutual coupling effect in antenna arrays via symmetric Toeplitz matrices","authors":"Sirani M. Perera ,&nbsp;Levi Lingsch ,&nbsp;Arjuna Madanayake ,&nbsp;Leonid Belostotski","doi":"10.1016/j.cam.2025.117152","DOIUrl":"10.1016/j.cam.2025.117152","url":null,"abstract":"&lt;div&gt;&lt;div&gt;In this paper, we solve systems of linear equations having an &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;mo&gt;×&lt;/mo&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; coefficient matrix as a symmetric Toeplitz matrix having elements found via the measured mutual coupling effects of electromagnetic fields caused by antenna array elements. This coefficient matrix is called the mutual coupling matrix. In general, these mutual coupling matrices are characterized as dense matrices. However,building on our prior work, we have introduced a symmetric Toeplitz structure, defining its elements through the self- and mutual coupling effects of antenna array elements. Thus, in this paper, we propose an algorithm to uncouple the mutual coupling effect of antenna arrays using &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;O&lt;/mi&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;mo&gt;log&lt;/mo&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; as opposed to &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;O&lt;/mi&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; complexity while defining the mutual coupling matrix as a matrix defined by the structure, i.e., a symmetric Toeplitz matrix. The proposed mutually coupled systems will be solved using a sparse factorization of the uncoupling matrices consisting of diagonal and butterfly matrices. The proposed algorithm has low arithmetic complexity compared to brute-force computations in solving systems of linear equations associated with mutual coupling matrices. The proposed factorization also leads to an alternative method to solve the system of linear equations having symmetric Toeplitz matrices as coefficient matrices with &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;O&lt;/mi&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;mo&gt;log&lt;/mo&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; as opposed to the &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;O&lt;/mi&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; complexity algorithm. To evaluate the accuracy and efficiency of the proposed Toeplitz solver, we have benchmarked our algorithm against highly optimized libraries such as &lt;em&gt;SciPy&lt;/em&gt;, &lt;em&gt;NumPy&lt;/em&gt;, and &lt;em&gt;PyTorch&lt;/em&gt;, specifically focusing on operations involving Toeplitz system solvers and inversion. We show that the proposed Toeplitz solver achieves exceptional efficiency, especially when utilizing GPU acceleration in &lt;em&gt;PyTorch&lt;/em&gt;, all while maintaining accuracy. For the demonstration of numerical results based on the proposed digital uncoupling algorithm and the effect of attenuation, we use S-parameters at 1.4 GHz of an 8-element sub-array and a 16-element sub-array. We show that the diagonal elements of the uncoupling matrices steadily decrease as one moves away from the main diagonal, highlighting the diminishing effect of mutual coupling and the predominance of self-coupling over mutual coupling. Finally, an 8-element signal flow graph will be presented to show the uncoupling of mutual c","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"477 ","pages":"Article 117152"},"PeriodicalIF":2.6,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145326668","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":"Fractional collocation method for linear neutral weakly singular Volterra integro-differential equations","authors":"Jiao Wen ,&nbsp;Mingfa Fei ,&nbsp;Zheng Ma","doi":"10.1016/j.cam.2025.117147","DOIUrl":"10.1016/j.cam.2025.117147","url":null,"abstract":"<div><div>In this paper, we investigate a fractional collocation method for linear neutral Volterra integro-differential equations with weakly singular kernels. The proposed method utilizes piecewise polynomials of fractional order, which match the typical singularity of this kind of problems well. A rigorous convergence analysis proves that the optimal orders of convergence can be attained under appropriate choices of the fractional exponent and graded mesh. Superconvergence results are also achieved. Finally, numerical experiments confirm the theoretical results.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"477 ","pages":"Article 117147"},"PeriodicalIF":2.6,"publicationDate":"2025-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145326265","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 line-search based SGD algorithm with Adaptive Importance Sampling","authors":"Filippo Camellini ,&nbsp;Serena Crisci ,&nbsp;Anna De Magistris ,&nbsp;Giorgia Franchini","doi":"10.1016/j.cam.2025.117120","DOIUrl":"10.1016/j.cam.2025.117120","url":null,"abstract":"<div><div>Stochastic Gradient methods are widely used in the field of supervised learning associated with big data. In this context, importance sampling-based algorithms have been proposed to minimize the variance of the stochastic gradient by introducing practical strategies to approximate the optimal sampling distribution, which is otherwise only theoretically accessible.</div><div>In this paper, we propose a scheme that combines stochastic gradient descent with adaptive importance sampling with automatic step-size selection based on a stochastic Armijo-type line-search. This approach makes the method robust to the choice of the initial step-size, which would otherwise require a tuning phase that is computationally expensive or even impractical in certain big data scenarios. Moreover, we introduce different mini-batch variants to foster the practical acceleration of the original scheme. Finally, numerical experiments are presented on real datasets to validate the proposed method in the context of supervised classification problems.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"477 ","pages":"Article 117120"},"PeriodicalIF":2.6,"publicationDate":"2025-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145277945","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":"Mathematical analysis and optimal control of a Caputo fractional diabetes system with parameter identification","authors":"Fırat Evirgen,&nbsp;Sümeyra Uçar,&nbsp;Necati Özdemir","doi":"10.1016/j.cam.2025.117151","DOIUrl":"10.1016/j.cam.2025.117151","url":null,"abstract":"<div><div>In this study, mathematical modeling of diabetes disease is handled with the Caputo fractional derivative, and the resulting fractional differential equation system is examined in detail. The existence of the solution of this system was mathematically proven under appropriate conditions. Then, for the management and treatment of diabetes, three control parameters are added, and the number of people with diabetes is tried to be kept in the desired range with the optimal control theory. In addition to this, our model gains from parameter estimation and fitting with more accurately generated parameters. The numerical results of the fractional model and the effect of the control parameters are determined with the optimal control approach on glucose levels, examined with various simulations, and presented graphically.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"477 ","pages":"Article 117151"},"PeriodicalIF":2.6,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145277881","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":"Multiplicative fractional integrals and derivatives for two-variable functions","authors":"Umut Bas,&nbsp;Abdullah Akkurt,&nbsp;Huseyin Yildirim","doi":"10.1016/j.cam.2025.117144","DOIUrl":"10.1016/j.cam.2025.117144","url":null,"abstract":"<div><div>This research examines the relationships between fractional calculus, a field that has recently attracted considerable research interest, and multiplicative calculus. In the Introduction, the arithmetic structure of multiplicative calculus is examined, along with the fundamental operational operators and their systematics. Additionally, the construction of generator functions and their role in deriving new arithmetic frameworks are demonstrated, with examples of alternative arithmetic systems provided. The Preliminaries present the fundamental concepts, definitions, and theorems of multiplicative calculus, including its derivative and integral operators. Subsequently, we present the main results obtained in this study. We introduce, for the first time, multiplicative fractional integral and derivative operators for functions of two variables. Subsequently, we establish several important properties of the proposed multiplicative fractional operators. Finally, we present some examples and graphical illustrations to demonstrate applications of these operators.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"476 ","pages":"Article 117144"},"PeriodicalIF":2.6,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269737","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":"Valuation of commodity option prices under a regime-switching model with stochastic convenience yield: Model calibration using flower pollination optimization algorithm","authors":"A. Hamdi ,&nbsp;I. Aksikas ,&nbsp;H. Smaoui ,&nbsp;F. Mehrdoust ,&nbsp;I. Noorani","doi":"10.1016/j.cam.2025.117150","DOIUrl":"10.1016/j.cam.2025.117150","url":null,"abstract":"<div><div>This research work seeks to construct a model for commodity spot prices by incorporating the concept of stochastic convenience yield within a Markov-switching framework. The model presented in this paper applies the Gibson-Schwartz commodity model under the risk-neutral measure, enabling regime-switching in the convenience yield and spot price dynamics. Using the WTI crude oil spot prices, the parameters involved in the proposed commodity regime-switching model are estimated by expectation–maximization algorithm. We then carry out a semi-analytical formula for the commodity futures contracts and European option price written on them. We calibrate the option pricing model parameters using the flower pollination optimization algorithm based on the European call option prices in WTI crude oil market. The results show that the provided Markov-switching model, whose parameters are calibrated by the flower pollination optimization algorithm is superior to the some common models in commodity literature.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"476 ","pages":"Article 117150"},"PeriodicalIF":2.6,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269738","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":"Optimized Schwarz method for the Stokes–Darcy problem with generalized interface conditions","authors":"Paula Strohbeck ,&nbsp;Marco Discacciati ,&nbsp;Iryna Rybak","doi":"10.1016/j.cam.2025.117141","DOIUrl":"10.1016/j.cam.2025.117141","url":null,"abstract":"<div><div>Due to their wide appearance in environmental settings as well as industrial and medical applications, the Stokes–Darcy problems with different sets of interface conditions establish an active research area in the community of mathematical modelers and computational scientists. For numerical simulation of such coupled problems in applications, robust and efficient computational algorithms are needed. In this work, we consider a generalization of the Beavers–Joseph interface condition recently developed using homogenization and boundary layer theory. This extension is applicable not only for the parallel flows to the fluid–porous interface as its predecessor, but also for arbitrary flow directions. To solve the Stokes–Darcy problem with these generalized interface conditions efficiently, we develop and analyze a Robin–Robin domain decomposition method using Fourier analysis to identify optimal weights in the Robin interface conditions. We study efficiency and robustness of the proposed method and provide numerical simulations which confirm the obtained theoretical results.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"477 ","pages":"Article 117141"},"PeriodicalIF":2.6,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145326670","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":"Numerical analysis of multi-patch discontinuous Galerkin isogeometric method for full-potential electronic structure calculations","authors":"Xiaoxu Li ,&nbsp;Xucheng Meng","doi":"10.1016/j.cam.2025.117125","DOIUrl":"10.1016/j.cam.2025.117125","url":null,"abstract":"<div><div>In this paper, we study the multi-patch discontinuous Galerkin isogeometric (DG-IGA) approximations for full-potential electronic structure calculations. We decompose the physical domain into several subdomains, represent each part of the wavefunction separately using B-spline basis functions, possibly with different degrees, on varying mesh sizes, and then combine them by DG methods. We also provide a rigorous <em>a priori</em> error analysis of the DG-IGA approximations for linear eigenvalue problems. Furthermore, this work offers a unified analysis framework for the DG-IGA method applied to a class of elliptic eigenvalue problems. Finally, we present several numerical experiments to verify our theoretical results.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"477 ","pages":"Article 117125"},"PeriodicalIF":2.6,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145326264","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 high-performance computing-based multi-island distributed migrating birds optimization algorithm implemented using MPI","authors":"Abdullah Tülek ,&nbsp;Gültekin Kuvat","doi":"10.1016/j.cam.2025.117145","DOIUrl":"10.1016/j.cam.2025.117145","url":null,"abstract":"<div><div>Metaheuristic algorithms are commonly used optimization techniques for solving high-dimensional complex problems. To achieve more successful results, improvements are made on these metaheuristic algorithms. This study aims to enhance the performance of the Migrating Birds Optimization (MBO) Algorithm, a neighborhood-based metaheuristic algorithm. To this end, MBO is implemented on a high-performance computing (HPC) architecture using Open MPI, and the Multi-Island Distributed Migrating Birds Optimization (MIDMBO) Algorithm is developed. MIDMBO is a distributed metaheuristic optimization algorithm that utilizes multiple islands, where successful solutions migrate between islands. The migration process between islands, facilitated by MPI, enables MIDMBO to generate more successful outcomes. Therefore, studies focused on the migration process are of great importance. In this study, the relationship between algorithm performance and variations in fundamental migration parameters such as migration rate, migration interval, and the number of islands is examined. Regression analyses are performed on the results obtained from MIDMBO, and the model that best explains performance variation is identified. Additionally, artificial neural network (ANN) models are constructed, and the degree to which changes in parameter values explain the results is evaluated.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":"477 ","pages":"Article 117145"},"PeriodicalIF":2.6,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145326261","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}