Improving Robustness of time series classifier with Neural ODE guided gradient based data augmentation

Improving Robustness of time series classifier with Neural ODE guided gradient based data augmentation Anindya Sarkar Mobiliya Bangalore, INDIA anindya.sarkar@mobiliya.com Abstract --Exploring adversarial attack vectors and studying their effects on machine learning algorithms has been of interest to researchers. Deep neural networks working with time series data have received lesser interest compared to their image counterparts in this context. In a recent finding, it has been revealed that current state-of-the-art deep learning time series classifiers are vulnerable to adversarial attacks. In this paper, we introduce two local gradient based and one spectral density based time series data augmentation techniques. We show that a model trained with data obtained using our techniques obtains state-of- the-art classification accuracy on various time series benchmarks. In addition, it improves the robustness of the model against some of the most common corruption techniques,such as Fast Gradient Sign Method (FGSM) and Basic Iterative Method (BIM). Index T erms --time series classification, adversarial training, gradient based adversarial attacks I.