Stochastic differential equations (SDEs) have been widely used to model real world random phenomena. Existing works mainly focus on the case where the time series is modeled by a single SDE, which might be restrictive for modeling time series with distributional shift. In this work, we propose a change point detection algorithm for time series modeled as neural SDEs. Given a time series dataset, the proposed method jointly learns the unknown change points and the parameters of distinct neural SDE models corresponding to each change point. Specifically, the SDEs are learned under the framework of generative adversarial networks (GANs) and the change points are detected based on the output of the GAN discriminator in a forward pass. At each step of the proposed algorithm, the change points and the SDE model parameters are updated in an alternating fashion. Numerical results on both synthetic and real datasets are provided to validate the performance of our algorithm in comparison to classical change point detection benchmarks, standard GAN-based neural SDEs, and other state-of-the-art deep generative models for time series data.

提出一种基于神经随机微分方程的时间序列变点检测算法，该算法使用生成对抗网络框架下的神经随机微分方程模型，通过GAN鉴别器的输出在前向传递中检测变点，并通过交替更新来学习未知的变点和不同变点对应的神经随机微分方程模型的参数。结果表明，该方法在合成和实际数据集上的性能比经典变点检测基准、标准GAN-based神经随机微分方程模型和其他深度生成模型更好。

具有变点的神经随机微分方程：一种生成对抗方法