C. Khamwandee and A. Saengprajak, “Roles of Activation Functions on the Polarization Modeling for the 1.2 kWp Proton Exchange Membrane Fuel Cells: A Focus on ReLU, Sigmoid, and Tanh”, J. Renew. Energy Smart Grid Technol., vol. 21, no. 1, pp. 107–118, Apr. 2026.