Scheduler for activation layer parameter using Keras callback
You will need to write a custom callback for this, that implements the on_epoch_end method. Roughly it should look something like this
class CustomCallback(keras.callbacks.Callback):

    def __init__(self, freq):
        super().__init__()
        self.freq = freq   # how often to change the parameter

    def on_epoch_end(self, epoch):

        if epoch % freq == 0 and epoch &gt; 0:

            weights = self.model.get_weights()

            # here you change the weight you want, e.g. it is the 5th layer
            weights[4] = weights[4] / 10

            self.model.set_weights(weights)