Stochastic differential equations play an important role in various applications when modeling systems that have either random perturbations or chaotic dynamics at faster time scales. The time evolution of the probability distribution of a stochastic differential equation is described by the Fokker-Planck equation, which is a second order parabolic partial differential equation. Previous work combined artificial neural network and Monte Carlo data to solve stationary Fokker-Planck equations. This paper extends this approach to time dependent Fokker-Planck equations. The focus is on the investigation of algorithms for training a neural network that has multi-scale loss functions. Additionally, a new approach for collocation point sampling is proposed. A few 1D and 2D numerical examples are demonstrated.
翻译:当模拟系统在较快的时间尺度上有随机扰动或混乱动态时,斯托克差异方程式在各种应用中起着重要作用。福克-普朗克方程式描述了斯托克-普朗克方程式概率分布的时间演变情况,这是第二顺序的抛物线部分差异方程式。以前的工作将人工神经网络和蒙特卡洛数据结合起来,以解决静止的福克克-普朗克方程式。本文将这一方法扩大到有时间依赖的福克-普朗克方程式。重点是对具有多尺度损失功能的神经网络的培训算法进行调查。此外,还提出了合用点取样的新方法。展示了几个1D和2D数字实例。