a) The standard RNN cell structure is shown below. Write its output activation formula (a ). Explain this simple structure and the operation of this standard RNN architecture using the formula and mentioning inputs, outputs, cell components, and parameters. a Softmax he a tanh Xt b) What are the problems of this simple standard RNN cell structure when its design is compared with the 4 design criteria of ideal RNN architecture? c) Draw the Gate Recurrent Unit (GRU) cell structure. Write the formulas describing the operation of the GRU. Explain this cell structure and the operation of this GRU architecture using the formulas and mentioning inputs, outputs, cell components, and parameters. d) What are the improvements of this GRU structure compared to the simple standard RNN cell structure? Activate Wind e) What are missing parts in this model? Why do we need a more complicated cell structure like LSTM ettings to a in some RNN applications?