Discontinuous Galerkin methods 4 Discontinuous galerkin Galerkin methods 4 Advection 2 Advection diffusion equation 2 Approximation spaces 2 Discontinuous Galerkin 2 Discontinuous Galerkin FEM 2 Elliptic problem 2 Error estimates 2 Image processing 2 Laplace transforms 2 Minimization 2 Numerical experiments 2 Numerical methods 2 Numerical tests 2 Optimization 2 P (x)-Laplacian 2 Perturbation techniques 2 Second orders 2 Singularly perturbed problem 2 Variable exponent spaces 2 Variable exponents 2 Variational problems 2 advection-diffusion equations 2 discontinuous Galerkin methods 2 exponentially fitted schemes 2