Journal of Computational and Applied Mathematics最新文献

Third order two-step Runge–Kutta–Chebyshev methods 三阶两步 Runge-Kutta-Chebyshev 方法

IF 2.1 2区数学

Journal of Computational and Applied Mathematics Pub Date : 2024-09-26 DOI: 10.1016/j.cam.2024.116291

引用次数: 0

Finite difference methods for stochastic Helmholtz equation driven by white noise 白噪声驱动的随机亥姆霍兹方程的有限差分法

IF 2.1 2区数学

Journal of Computational and Applied Mathematics Pub Date : 2024-09-20 DOI: 10.1016/j.cam.2024.116286

引用次数: 0

Poisson noise removal based on non-convex hybrid regularizers 基于非凸混合正则的泊松噪声消除

IF 2.1 2区数学

Journal of Computational and Applied Mathematics Pub Date : 2024-09-19 DOI: 10.1016/j.cam.2024.116289

{"title":"Poisson noise removal based on non-convex hybrid regularizers","authors":"","doi":"10.1016/j.cam.2024.116289","DOIUrl":"10.1016/j.cam.2024.116289","url":null,"abstract":"<div><div>The presence of TV regularizer always induces an unsatisfactory staircase effect. To overcome the staircase while better sustaining edge information, this work proposes a novel model for Poisson noise removal. The model is based on non-convex mixed regularizers, which involves introducing a non-convex penalty into a composition of the total variation and the higher-order total variation. The iterative reweighted <span><math><msub><mrow><mi>l</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> algorithm was used to convert the non-convex model into a convex one. The classic alternating direction method of multipliers was then employed to obtain approximate solutions of the model. When applying this model to degraded images contaminated by Poisson noise of medium to high intensity, its performance in noise suppression was tested. The regularizer was compared with others in the terms of the visual effect of the picture, time cost, and several commonly accepted quantitative indicators for evaluation, such as peak signal-to-noise ratio, feature similarity index and structural similarity index. Numerical experiments showed that the present model not only eliminates block artifacts but also retains sharp edges.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142326348","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

Robust H∞ control for LFC of discrete T–S fuzzy MAPS with DFIG and time-varying delays 带双馈变流器和时变延迟的离散 T-S 模糊 MAPS LFC 的鲁棒 H∞ 控制

IF 2.1 2区数学

Journal of Computational and Applied Mathematics Pub Date : 2024-09-18 DOI: 10.1016/j.cam.2024.116271

引用次数: 0

Fading regularization method for an inverse boundary value problem associated with the biharmonic equation 与双谐方程相关的反边界值问题的消隐正则化方法

IF 2.1 2区数学

Journal of Computational and Applied Mathematics Pub Date : 2024-09-18 DOI: 10.1016/j.cam.2024.116285

引用次数: 0

Error analysis of the explicit-invariant energy quadratization (EIEQ) numerical scheme for solving the Allen–Cahn equation 用于求解艾伦-卡恩方程的显式不变能量四分法（EIEQ）数值方案的误差分析

IF 2.1 2区数学

Journal of Computational and Applied Mathematics Pub Date : 2024-09-16 DOI: 10.1016/j.cam.2024.116224

引用次数: 0

Generalized Multiscale Finite Element Method for discrete network (graph) models 离散网络（图）模型的广义多尺度有限元法

IF 2.1 2区数学

Journal of Computational and Applied Mathematics Pub Date : 2024-09-13 DOI: 10.1016/j.cam.2024.116275

引用次数: 0

Unconditional error analysis of the linearized transformed L1 virtual element method for nonlinear coupled time-fractional Schrödinger equations 非线性耦合时分数薛定谔方程线性化变换 L1 虚拟元素法的无条件误差分析

IF 2.1 2区数学

Journal of Computational and Applied Mathematics Pub Date : 2024-09-13 DOI: 10.1016/j.cam.2024.116283

{"title":"Unconditional error analysis of the linearized transformed L1 virtual element method for nonlinear coupled time-fractional Schrödinger equations","authors":"","doi":"10.1016/j.cam.2024.116283","DOIUrl":"10.1016/j.cam.2024.116283","url":null,"abstract":"<div><div>This paper constructs a linearized transformed <span><math><mrow><mi>L</mi><mn>1</mn></mrow></math></span> virtual element method for the generalized nonlinear coupled time-fractional Schrödinger equations. The solutions to such problems typically exhibit singular behavior at the beginning. To avoid this pitfall, we introduce an identical <span><math><mi>s</mi></math></span>-fractional differential system derived from a smoothing transformation of variables <span><math><mrow><mi>t</mi><mo>=</mo><msup><mrow><mi>s</mi></mrow><mrow><mn>1</mn><mo>/</mo><mi>α</mi></mrow></msup></mrow></math></span>, <span><math><mrow><mn>0</mn><mo><</mo><mi>α</mi><mo><</mo><mn>1</mn></mrow></math></span>. By utilizing the discrete complementary convolution kernels, we prove the boundedness and error estimates of the solution of time-discrete system. Moreover, the unconditionally optimal error bounds of the proposed fully discrete scheme are derived in <span><math><msup><mrow><mi>L</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span>-norm without restriction on the grid ratio. Finally, numerical tests on a set of polygonal meshes are presented to verify the theoretical results.</div></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142312509","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 space transformed finite element method for elliptic interface problems in Rn Rn 中椭圆界面问题的新空间变换有限元法

IF 2.1 2区数学

Journal of Computational and Applied Mathematics Pub Date : 2024-09-12 DOI: 10.1016/j.cam.2024.116277

{"title":"A new space transformed finite element method for elliptic interface problems in Rn","authors":"","doi":"10.1016/j.cam.2024.116277","DOIUrl":"10.1016/j.cam.2024.116277","url":null,"abstract":"<div><p>Interface problems, where distinct materials or physical domains meet, pose significant challenges in numerical simulations due to the discontinuities and sharp gradients across interfaces. Traditional finite element methods struggle to capture such behavior accurately. A new space transformed finite element method (ST-FEM) is developed for solving elliptic interface problems in <span><math><msup><mrow><mi>R</mi></mrow><mrow><mi>n</mi></mrow></msup></math></span>. A homeomorphic stretching transformation is introduced to obtain an equivalent problem in the transformed domain which can be solved easily, and the solution can be projected back to original domain by the inverse transformation. Compared with the existing methods, this new scheme has capability of handling discontinuities across the interface. The proposed approach has advantages in circumventing interface approximation properties and reducing the degree of freedom. We initially develop ST-FEM for elliptic problems and subsequently expand upon this concept to address elliptic interface problems. We prove optimal a priori error estimates in the <span><math><msup><mrow><mi>H</mi></mrow><mrow><mn>1</mn></mrow></msup></math></span> and <span><math><msup><mrow><mi>L</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> norms, and quasi-optimal error estimate for the maximum norm. Finally, numerical experiments demonstrate the superior accuracy and convergence properties of the ST-FEM when compared to the standard finite element method. The interface is assumed to be a <span><math><mrow><mo>(</mo><mi>n</mi><mo>−</mo><mn>1</mn><mo>)</mo></mrow></math></span>-sphere, nevertheless, our analysis can cover symmetric domains such as an ellipsoid or a cylinder.</p></div>","PeriodicalId":50226,"journal":{"name":"Journal of Computational and Applied Mathematics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142241453","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

Representation computation for the hypergeometric function of a Hermitian matrix argument 赫米矩阵参数的超几何函数的表示计算

IF 2.1 2区数学

Journal of Computational and Applied Mathematics Pub Date : 2024-09-12 DOI: 10.1016/j.cam.2024.116258

引用次数: 0