arXiv:2507.10241cs.LG2025-07被引 7

用自适应核优化提升PDE求解精度,尤其擅长处理陡变梯度问题。

Kernel-Adaptive PI-ELMs for Forward and Inverse Problems in PDEs with Sharp Gradients

  • 通过贝叶斯优化动态调整RBF核中心与宽度分布,实现局部自适应
  • 在1D/2D测试中精准捕捉陡峭层,参数量仅为先进方法的十分之一
  • 适用于含尖锐梯度的正反问题,可扩展至非线性稳态流体方程求解

物理信息机器学习框架如物理信息神经网络(PINNs)和物理信息极限学习机(PI-ELMs)在求解偏微分方程(PDEs)方面表现优异,但在局部尖锐梯度和奇异摄动情形下效果受限:PINNs受频谱偏差影响,而PI-ELMs因单次、非自适应形式而性能不足。本文提出核自适应物理信息极限学习机(KAPI-ELM),在低维、物理解释性强的超参数空间中进行贝叶斯优化,调控径向基函数(RBF)中心与宽度分布。该方法将高维权重优化转化为低维分布搜索,可在陡变区域实现靶向核细化,同时通过调节RBF支撑域提升光滑区域解的保真度。在含尖锐梯度的基准前向与逆向问题(1D对流-扩散方程与2D泊松方程)上验证,KAPI-ELM能准确解析陡峭层,改善光滑解质量,并稳健恢复物理参数,性能媲美或超越扩展型函数连接理论(X-TFC),且可调参数数量接近其十分之一。进一步通过课程式线性化方法求解稳态纳维-斯托克斯方程,成功获得雷诺数Re=100的驱动腔流动基准解,表明KAPI-ELM是一种高效统一的前向与逆向PDE求解方法,特别适用于挑战性的尖锐梯度场景。

原文摘要 · Abstract (English)

Physics-informed machine learning frameworks such as Physics-Informed Neural Networks (PINNs) and Physics-Informed Extreme Learning Machines (PI-ELMs) have shown great promise for solving partial differential equations (PDEs) but struggle with localized sharp gradients and singularly perturbed regimes, PINNs due to spectral bias and PI-ELMs due to their single-shot, non-adaptive formulation. We propose the Kernel-Adaptive Physics-Informed Extreme Learning Machine (KAPI-ELM), which performs Bayesian optimization over a low-dimensional, physically interpretable hyperparameter space governing the distribution of Radial Basis Function (RBF) centers and widths. This converts high-dimensional weight optimization into a low-dimensional distributional search, enabling targeted kernel refinement in regions with sharp gradients while also improving baseline solutions in smooth-flow regimes by tuning RBF supports. KAPI-ELM is validated on benchmark forward and inverse problems (1D convection-diffusion and 2D Poisson) involving PDEs with sharp gradients. It accurately resolves steep layers, improves smooth-solution fidelity, and recovers physical parameters robustly, matching or surpassing advanced methods such as the extended Theory of Functional Connections (X-TFC) with nearly an order of magnitude fewer tunable parameters. An extension to nonlinear problems is demonstrated by a curriculum-based solution of the steady Navier-Stokes equations via successive linearizations, yielding stable solutions for benchmark lid-driven cavity flow up to Re=100. These results indicate that KAPI-ELM provides an efficient and unified approach for forward and inverse PDEs, particularly in challenging sharp-gradient regimes.

PDE求解自适应核物理信息学习陡变梯度

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