A Numerically Efficient Dissipation-Preserving Implicit Method for a Nonlinear Multidimensional Fractional Wave Equation
This work is motivated by the investigation of a fractional extension of a general nonlinear multidimensional wave equation with damping. The model under study considers partial derivatives of orders in $$(0, 1) \cup (1, 2]$$(0,1)?(1,2] with respect to ...
The Unstructured Mesh Finite Element Method for the Two-Dimensional Multi-term Time---Space Fractional Diffusion-Wave Equation on an Irregular Convex Domain
In this paper, the two-dimensional multi-term time-space fractional diffusion-wave equation on an irregular convex domain is considered as a much more general case for wider applications in fluid mechanics. A novel unstructured mesh finite element ...
A Least-Squares/Relaxation Method for the Numerical Solution of the Three-Dimensional Elliptic Monge---Ampère Equation
In this article, we address the numerical solution of the Dirichlet problem for the three-dimensional elliptic Monge---Ampère equation using a least-squares/relaxation approach. The relaxation algorithm allows the decoupling of the differential ...
An Efficient Algorithm for Matrix-Valued and Vector-Valued Optimal Mass Transport
We present an efficient algorithm for recent generalizations of optimal mass transport theory to matrix-valued and vector-valued densities. These generalizations lead to several applications including diffusion tensor imaging, color image processing, ...
MultiGrid Preconditioners for Mixed Finite Element Methods of the Vector Laplacian
Due to the indefiniteness and poor spectral properties, the discretized linear algebraic system of the vector Laplacian by mixed finite element methods is hard to solve. A block diagonal preconditioner has been developed and shown to be an effective ...
Computing the Matrix Mittag-Leffler Function with Applications to Fractional Calculus
The computation of the Mittag-Leffler (ML) function with matrix arguments, and some applications in fractional calculus, are discussed. In general the evaluation of a scalar function in matrix arguments may require the computation of derivatives of ...
The BR1 Scheme is Stable for the Compressible Navier---Stokes Equations
In this work we prove that the original (Bassi and Rebay in J Comput Phys 131:267---279, 1997) scheme (BR1) for the discretization of second order viscous terms within the discontinuous Galerkin collocation spectral element method (DGSEM) with Gauss ...
Correction to: The BR1 Scheme is Stable for the Compressible Navier---Stokes Equations
An open-source code that implements the entropy stable discontinuous Galerkin scheme with Legendere---Gauss---Lobatto collocation (DGSEM) on curved unstructured hexahedral grids for compressible Navier---Stokes equations (NSE) is available at github.com/...
Optimization with Respect to Order in a Fractional Diffusion Model: Analysis, Approximation and Algorithmic Aspects
We consider an identification (inverse) problem, where the state $${\mathsf {u}}$$u is governed by a fractional elliptic equation and the unknown variable corresponds to the order $$s \in (0,1)$$sý(0,1) of the underlying operator. We study the existence ...
Stability and Convergence Analysis of a Class of Continuous Piecewise Polynomial Approximations for Time-Fractional Differential Equations
We propose and study a class of numerical schemes to approximate time-fractional differential equations. The methods are based on the approximations of the Caputo fractional derivative of order $$\alpha \in (0, 1)$$??(0,1) by using continuous piecewise ...
High Order Multi-dimensional Characteristics Tracing for the Incompressible Euler Equation and the Guiding-Center Vlasov Equation
In this paper, we propose a high order characteristics tracing scheme for the two-dimensional nonlinear incompressible Euler system in vorticity stream function formulation and the guiding center Vlasov model. Such a scheme is incorporated into a semi-...
A Stable Fast Time-Stepping Method for Fractional Integral and Derivative Operators
A unified fast time-stepping method for both fractional integral and derivative operators is proposed. The fractional operator is decomposed into a local part with memory length $$\varDelta T$$ΔT and a history part, where the local part is approximated ...
Finite Element Approximation for the Fractional Eigenvalue Problem
The purpose of this work is to study a finite element method for finding solutions to the eigenvalue problem for the fractional Laplacian. We prove that the discrete eigenvalue problem converges to the continuous one and we show the order of such ...
High Spatial Order Energy Stable FDTD Methods for Maxwell's Equations in Nonlinear Optical Media in One Dimension
In this paper, we consider electromagnetic (EM) wave propagation in nonlinear optical media in one spatial dimension. We model the EM wave propagation by the time-dependent Maxwell's equations coupled with a system of nonlinear ordinary differential ...
Dispersion Properties of Explicit Finite Element Methods for Wave Propagation Modelling on Tetrahedral Meshes
We analyse the dispersion properties of two types of explicit finite element methods for modelling acoustic and elastic wave propagation on tetrahedral meshes, namely mass-lumped finite element methods and symmetric interior penalty discontinuous ...
Curvilinear Mesh Adaptation Using Radial Basis Function Interpolation and Smoothing
We present a new iterative technique based on radial basis function (RBF) interpolation and smoothing for the generation and smoothing of curvilinear meshes from straight-sided or other curvilinear meshes. Our technique approximates the coordinate ...
A Robust Numerical Method for the Random Interface Grating Problem via Shape Calculus, Weak Galerkin Method, and Low-Rank Approximation
We present an efficient numerical algorithm to solve random interface grating problems based on a combination of shape derivatives, the weak Galerkin method, and a low-rank approximation technique. By using the asymptotic perturbation approach via shape ...
Fully Computable a Posteriori Error Bounds for Hybridizable Discontinuous Galerkin Finite Element Approximations
We derive a posteriori error estimates for the hybridizable discontinuous Galerkin (HDG) methods, including both the primal and mixed formulations, for the approximation of a linear second-order elliptic problem on conforming simplicial meshes in two ...
A Mixed Discontinuous Galerkin Method Without Interior Penalty for Time-Dependent Fourth Order Problems
A novel discontinuous Galerkin (DG) method is developed to solve time-dependent bi-harmonic type equations involving fourth derivatives in one and multiple space dimensions. We present the spatial DG discretization based on a mixed formulation and ...
A Hybrid Staggered Discontinuous Galerkin Method for KdV Equations
A hybrid staggered discontinuous Galerkin method is developed for the Korteweg---de Vries equation. The equation is written into a system of first order equations by introducing auxiliary variables. Two sets of finite element functions are introduced to ...
A Sparse Grid Stochastic Collocation Upwind Finite Volume Element Method for the Constrained Optimal Control Problem Governed by Random Convection Diffusion Equations
In this paper, we deal with an optimal control problem governed by the convection diffusion equations with random field in its coefficients. Mathematically, we prove the necessary and sufficient optimality conditions for the optimal control problem. ...
Hybrid Optimized Low-Dissipation and Adaptive MUSCL Reconstruction Technique for Hyperbolic Conservation Laws
A new hybrid optimized low-dissipation and adaptive MUSCL scheme is present for finite volume method. The proposed scheme, based on an optimized linear scheme with monotonicity preserving limitation and an adaptive MUSCL scheme, emphasizes on the ...
Shock Regularization with Smoothness-Increasing Accuracy-Conserving Dirac-Delta Polynomial Kernels
A smoothness-increasing accuracy conserving filtering approach to the regularization of discontinuities is presented for single domain spectral collocation approximations of hyperbolic conservation laws. The filter is based on convolution of a ...
PCBC: Quasiconformality of Point Cloud Mappings
The study of surface mappings or deformations plays an important role for various applications in computer visions and graphics. An accurate and effective method to measure and control geometric distortions of the mapping is therefore necessary. ...
A Linear Implicit Finite Difference Discretization of the Schrödinger---Hirota Equation
A new linear implicit finite difference method is proposed for the approximation of the solution to a periodic, initial value problem for a Schrödinger---Hirota equation. Optimal, second order convergence in the discrete $$H^1$$H1-norm is proved, ...
Efficient Spectral Methods for Some Singular Eigenvalue Problems
We propose and analyze some efficient spectral/spectral element methods to solve singular eigenvalue problems related to the Schrödinger operator with an inverse-power potential. For the Schrödinger eigenvalue problem $$-\Delta u +V(x)u=\lambda u$$-Δu+V(...