We address a new numerical scheme based on a class of machine learning methods, the so-called Extreme Learning Machines with both sigmoidal and radial-basis functions, for the computation of steady-state solutions and the construction of (one dimensional) bifurcation diagrams of nonlinear partial differential equations (PDEs). For our illustrations, we considered two benchmark problems, namely (a) the one-dimensional viscous Burgers with both homogeneous (Dirichlet) and non-homogeneous mixed boundary conditions, and, (b) the one and two-dimensional Liouville-Bratu-Gelfand PDEs with homogeneous Dirichlet boundary conditions. For the one-dimensional Burgers and Bratu PDEs, exact analytical solutions are available and used for comparison purposes against the numerical derived solutions. Furthermore, the numerical efficiency (in terms of accuracy and size of the grid) of the proposed numerical machine learning scheme is compared against central finite differences (FD) and Galerkin weighted-residuals finite-element methods (FEM). We show that the proposed ELM numerical method outperforms both FD and FEM methods for medium to large sized grids, while provides equivalent results with the FEM for low to medium sized grids.
翻译:我们处理基于一类机器学习方法的新数字方案,即所谓的具有共振和辐射基底功能的极端学习机器,用于计算稳定状态解决方案和构建(一维)非线性部分差异方程式的双向图(PDEs)。关于我们的插图,我们考虑了两个基准问题,即(a) 单维面粘结汉堡机,具有同质(Drichlet)和非同源混合边界条件,以及(b) 一维和二维Liouville-Bratu-Gelfand PDEs,具有均匀的 Dirichlet边界条件。对于一维布尔格斯和Bratu PDEs,有精确的分析解决方案,用于与数字衍生解决方案进行比较。此外,拟议数字机器学习计划的数字效率(以网格的精度和大小衡量)与中央有限差异(FD)和Galerkin加权-resultial-elfand PDEs。我们显示,拟议的ELM 数字网格方法提供了中等至中等的中等的中等式方法,同时提供了FEMFM格式的中等至中等的网格方法。