Recurrent Neural Networks for Multivariate Time Series with Missing Values

Gated Recurrent Units (GRUs) are gating mechanisms introduced in 2014 by Cho et al. Unlike LSTMs that have 3 gates, in GRUs have 2 gates to operate the time series data. Its main structure can be seen in Figure 3, and for further understanding, Understanding GRU Networks is highly recommended. Also, if you want to understand LSTMs and GRUs in the place, this article is recommended: Illustrated Guide to LSTM's and GRU's: A step by step explanation.