Academia.eduAcademia.edu

Numerical Mathematics

description244 papers
group50 followers
lightbulbAbout this topic
Numerical Mathematics is a branch of mathematics that focuses on the development and analysis of algorithms for approximating solutions to mathematical problems that cannot be solved analytically. It encompasses techniques for numerical computation, error analysis, and the study of convergence and stability of numerical methods.
lightbulbAbout this topic
Numerical Mathematics is a branch of mathematics that focuses on the development and analysis of algorithms for approximating solutions to mathematical problems that cannot be solved analytically. It encompasses techniques for numerical computation, error analysis, and the study of convergence and stability of numerical methods.

Key research themes

1. How can numerical methods be optimized and adapted for solving nonlinear equations with multiple roots and applied engineering problems?

This theme investigates the development and analysis of iterative numerical methods tailored to approximate multiple roots of nonlinear equations, with a focus on efficiency, convergence order, and applicability to complex real-world engineering models. Key interests include derivative-free methods to reduce computational cost, simultaneous methods for multiple root estimation, and the implementation of these schemes in engineering contexts such as biomedical flows and fluid mechanics.

Key finding: Developed a new derivative-free multipoint iterative method with fourth-order convergence for multiple roots, showing smaller residual errors and fewer iterations compared to existing methods; providing a practical... Read more
Key finding: Constructed an optimal order four single root finding method and generalized it to a simultaneous iterative technique of order six for estimating all roots of nonlinear equations, validated across nonlinear equations from... Read more
Key finding: Provided a comprehensive survey and methodological framework that balances general numerical techniques and finance-specific methods, such as solving nonlinear equations in financial models, by analyzing algorithm convergence... Read more

2. What advancements in numerical methods enhance the accuracy and efficiency of solving ordinary differential equations (ODEs) in engineering and scientific contexts?

This research area concerns the analysis, comparison, and improvement of time-stepping numerical methods like Euler's method, Taylor's series method, and Runge-Kutta methods aimed at solving ODEs with higher accuracy and computational efficiency. Emphasis lies on the mathematical interpretation, error reduction strategies, and implementation aspects, including software utilization (MATLAB, FORTRAN), with applications to initial value problems in engineering.

Key finding: Thoroughly compared Euler's, Taylor's, and Runge-Kutta methods for first-order ODEs, establishing that the Runge-Kutta method provides superior accuracy in approximating solutions by verifying this through numerical... Read more
Key finding: Introduced a modification to standard discontinuous Galerkin (DG) time discretization for parabolic PDEs with inhomogeneous linear constraints that ensures optimal convergence rates; theoretical error bounds and... Read more
Key finding: Analyzed a finite element method with Nédélec elements for vorticity and continuous polynomials for Bernoulli pressure in solving Oseen equations, providing L2-norm a priori error estimates and adaptive mesh refinement guided... Read more

3. How can high-order and adaptive numerical finite element methods be developed and analyzed for complex geometries and parametric PDE problems?

This theme focuses on the design and rigorous analysis of advanced finite element discretizations, including higher-order isoparametric, hybridizable discontinuous Galerkin (HDG), and trace finite element methods. Research investigates geometry approximation, adaptive refinement, parametric dependence, and model order reduction for PDEs such as elliptic interface problems, surface Stokes equations, and shallow water equations, with goals of improving accuracy, computational efficiency, and applicability in engineering and physical sciences.

Key finding: Extended previous H1-norm optimal error analysis to derive optimal L2-norm error bounds for a high-order unfitted isoparametric finite element method that approximates smooth implicitly defined interfaces, enabling... Read more
Key finding: Presented stability and optimal order convergence proofs for a higher-order trace finite element method applied to surface Stokes equations, addressing tangential velocity constraints and geometry approximation errors;... Read more
Key finding: Developed a reduced order modeling framework using Proper Orthogonal Decomposition and Galerkin projection to efficiently solve nonlinear time-dependent optimal control problems governed by parametrized shallow water... Read more
Key finding: Extended analysis of symmetric interior penalty hybridizable discontinuous Galerkin (IP-H) schemes to include non-symmetric families, deriving optimal a priori error estimates and clarifying relationships to classical... Read more
Key finding: Derived probabilistic models capturing the relative accuracy between finite elements of different polynomial degrees over families of meshes and sequences of simplexes, facilitating new approaches to guide adaptive mesh... Read more

All papers in Numerical Mathematics

Mortaring the two-dimensional edge finite elements for the discretization of some electromagnetic models∗
We propose a non uniform web spline based finite element analysis for elliptic partial differential equation with the gradient type nonlinearity in their principal coefficients like p-laplacian equation and Quasi-Newtonian fluid flow... more
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or... more
A multipoint boundary value problem is considered. The existence and uniqueness of solution is proved. Then, for the numerical solution, a general collocation method is proposed.Numerical experiments con rm theoretical results.
In this work we propose reduced order methods as a reliable strategy to efficiently solve parametrized optimal control problems governed by shallow waters equations in a solution tracking setting. The physical parametrized model we deal... more
A new technique for the implementation of cell-centered finite volume schemes is proposed. It is based on an equivalence between these schemes and the non-conforming Crouzeix-Raviart finite element approximation. Though the implementation... more
This paper derives a posteriori error estimates for the mixed numerical approximation of the Laplace eigenvalue problem with homogeneous Dirichlet boundary conditions. In particular, the resulting error estimator constitutes an upper... more
This paper derives a posteriori error estimates for the mixed numerical approximation of the Laplace eigenvalue problem with homogeneous Dirichlet boundary conditions. In particular, the resulting error estimator constitutes an upper... more
This paper derives a posteriori error estimates for the mixed numerical approximation of the Laplace eigenvalue problem with homogeneous Dirichlet boundary conditions. In particular, the resulting error estimator constitutes a guaranteed... more
In this paper, we consider an optimal control problem governed by elliptic differential equations posed in a three-field formulation. Using the gradient as a new unknown we write a weak equation for the gradient using a Lagrange... more
In this paper, a numerical method is developed to compute an approximate solution of high-order linear complex differential equations in elliptic domains. By using collocation points and Bessel polynomials, this method transforms the... more
In this study, we suggest a collocation method to solve a class of the nonlinear differential equations under the mixed conditions in terms of the Bessel polynomials. The method is based on the matrix forms of the Bessel polynomials and... more
In this study, we suggest a collocation method to solve a class of the nonlinear differential equations under the mixed conditions in terms of the Bessel polynomials. The method is based on the matrix forms of the Bessel polynomials and... more
In this work, we present analysis of a scaled time-dependent reaction–diffusion system modeling three competitive species dynamics that is of Lotka–Volterra type for coexistence, permanence and stability. The linear analysis is based on... more
This chapter is devoted to the discussion of selected topics related to finite element software. In Section B. 1 we present an efficient way of connecting the packages PETSc, Trilinos and UMFPACK to a finite element solver. Section B.2... more
1. Zobecněné vlastní vektory. V dalším budeme uvažovat linearní operátory α : V → V , kde V je vektorový prostor dimenze n nad tělesem C. Zatím jsme se zabývali většinou tzv. diagonalizovatelnými lineárními operátory, tj. operátory α,... more
In this paper, a guaranteed equilibrated error estimator is proposed for the harmonic magnetodynamic formulation of the Maxwell's system. This system is recast in two classical potential formulations, which are solved by a Finite Element... more
Obávám se, 3⁄4e není mo3⁄4no se nauèit kvantovou mechaniku "poøádnì a jednou prov3⁄4dy", nýbr3⁄4 3⁄4e se jedná o postupný proces. Cílem tohoto textu je pøedev1ím uvedení do problematiky a seznámení se s nejdùle3⁄4itìj1ími... more
Journal of Numerical Mathematics 'Just Accepted' Papers have undergone the complete peer-review process. However, none of the additional editorial preparation, which includes copy editing, typesetting and proofreading, has been performed.... more
Methods of analysis and synthesis of linear feedback shift registers (LFSR) are described. The text is focused on the methods of designing autonomous test devices for easy testability of digital circuits.
En Boukrouche y Tarzia, Comput. Optim. Appl., 53(2012), 375-392, se considera un problema de control óptimo continuo gobernado por una inecuación variacional elíptica siendo la variable de control la fuente de energía interna del sistema... more
En Boukrouche y Tarzia, Comput. Optim. Appl., 53(2012), 375-392, se considera un problema de control optimo continuo gobernado por una inecuacion variacional eliptica siendo la variable de control la fuente de energia interna del sistema... more
The content of this booklet, written in Portuguese, is an introduction to Optimization intended for undergraduate courses. The linear programming approach is carried out by applying the Simplex method that uses tableau. The final chapter... more
We identify discontinuous Galerkin methods for second-order elliptic problems in several space dimensions having superconvergence properties similar to those of the Raviart-Thomas and the Brezzi-Douglas-Marini mixed methods. These methods... more
We consider the Mixed Interpolated (Tensorial Components) finite element families for the Reissner-Mindlin plate model. For the case of a convex domain with clamped boundary conditions we prove regularity results and derive new error... more
An overlapping domain decomposition, additive Schwarz, conjugate gradient method is presented for the solution of the linear systems which arise when orthogonal spline collocation with piecewise Hermite bicubics is applied to the... more
We present a higher order generalization for relaxation methods in the framework presented by Jin and Xin in [10]. The schemes employ general higher order integration for spatial discretization and higher order implicit-explicit (IMEX)... more
In this paper, we propose an extended mixed finite element method for elliptic interface problems. By adding some stabilization terms, we present a mixed approximation form based on Brezzi-Douglas-Marini element space and the piecewise... more
We consider the Stokes Problem on a plane polygonal domain Ω ⊂ R 2. We propose a finite element method for overlapping or nonmatching grids for the Stokes Problem based on the partition of unity method. We prove that the discrete inf-sup... more
The convergence of an adaptive mixed finite element method for general second order linear elliptic problems defined on simply connected bounded polygonal domains is analyzed in this paper. The main difficulties in the analysis are posed... more
In this article, we study theoretically and numerically the heat equation coupled with Darcy's law by a nonlinear viscosity depending on the temperature. We establish existence and uniqueness of the exact solution by using a Galerkin... more
The Schwarz algorithm for a class of elliptic quasi-variational inequalities with nonlinear source terms is studied in this work. The authors prove a new error estimate in uniform norm, making use of a stability property of the discrete... more
The recently proposed locally refined B-splines, denoted LR B-splines, by Dokken et al. [6] may have the potential to be a framework for isogeometric analysis to enable future interoperable computer aided design and finite element... more
Using the Fourier series as a projection in the Galerkin method, we approach the solution of the Cauchy singular integral equation. This study is carried in \(L^2\). Numerical examples are developped to show the effectiveness of this... more
La presente investigación tiene como objetivos específicos determinar polinomios cuadráticos, cúbicos y de quinto grado cuyo método de Newton asociado tenga órbitas periódicas repulsoras, así como obtener polinomios cúbicos cuyas... more
In many applications, high-dimensional data points can be well represented by low-dimensional subspaces. To identify the subspaces, it is important to capture a global and local structure of the data which is achieved by imposing low-rank... more
The proof of Fermat's Last Theorem for exponent 3 is based on the fact that Fermat's Diophantine sum equation x^3+y^3+z^3=0 is equivalent to the product form equation (3k)^3=(x+y+z)^3=3(x+y)(z+x)(z+y), where x+y,z+x,z+y are coprime... more
The Schwarz algorithm for a class of elliptic quasi-variational inequalities with nonlinear source terms is studied in this work. The authors prove a new error estimate in uniform norm, making use of a stability property of the discrete... more
In this paper we prove some new symmetry results for the extremals of the Caffarelli-Kohn-Nirenberg inequalities, in any dimension larger or equal to 2.
We consider a class of parameter-dependent optimal control problems of elliptic PDEs with constraints of general type on the control variable. Applying the concept of variational discretization, [4], together with techniques from the... more
This work frames the problem of constructing non-oscillatory entropy stable fluxes as a least square optimization problem. A flux sign stability condition is defined for a pair of entropy conservative flux (F∗ ) and a non-oscillatory flux... more
In this paper, new renements and improvements of Mitrinovic-Cusa and related inequalities are presented. We prove in particular for 0 < x < π 2 and any n ≥ 5 Pn(x) < (sin x) 2 −x 3 cot x < Pn−1(x)+ 2 π 2n − n−1 k=3 a k 2 π 2n−2k x 2n... more
We address the solution of large-scale eigenvalue problems that appear in the motion simulation of complex macromolecules on multithreaded platforms, consisting of (one or more) multicore processors and possibly a graphics processor... more
We present a four-field virtual element discretization for the time-dependent resistive magnetohydrodynamics equations in three space dimensions, focusing on the semi-discrete formulation. The proposed method employs general polyhedral... more
We prove a new inequality which improves on the classical Hardy inequality in the sense that a nonlinear integral quantity with super-quadratic growth, which is computed with respect to an inverse square weight, is controlled by the... more
Download research papers for free!