A New Method of Secure Authentication Based on Electromagnetic Signatures of Chipless RFID Tags and Machine Learning Approaches

. 2020 Nov 9;20(21):6385. doi: 10.3390/s20216385

Algorithm A4: Adam Algorithm

\begin{array}{l} g_{t} \leftarrow \nabla_{θ_{t - 1}} f (θ_{t - 1}) \\ m_{t} \leftarrow μ m_{t - 1} + (1 - μ) g_{t} \\ \hat{m_{t}} \leftarrow \frac{m_{t}}{1 - μ^{t}} \\ n_{t} \leftarrow v m_{t - 1} + (1 - v) g_{t}^{2} \\ \hat{n_{t}} \leftarrow \frac{n_{t}}{1 - v^{t}} \\ θ_{t} \leftarrow θ_{t - 1} - η \frac{\hat{m_{t}}}{\sqrt{\hat{n_{t}} + ε}} \end{array}