fraction proposal network of FQF

[zhangpaipai]

Hi,
I have some problems about fraction proposal network of FQF:
1.why set fraction_lr=5e-5*fqf_factor(0.000001)=5e-11, which is very small? And I found that the tau_hats distibution almost had no change during the training.
2.why apply initialize_weights_xavier(x, gain=0.01)? When I trained, I found if I didn't apply this initialization, gradient explosion would happen sometiomes.
3.why use RMSprop, and set alpha=0.95, eps=0.00001, of which the default values are 0.99 and 10e-8 respectively.
4.And I found that the tau_hats distibution almost had no change during the training of qbert. Is it the key of this algorithm?
thanks!