replace the convolution in Resnet with PConv

[wanderer1230]

Great work! I wonder if the model performance will be improved when replacing the convolution in Resnet with PConv.
Have you done similar experiments？

[JierunChen]

@wanderer1230 Hi, if the Conv is directly replaced by PConv without other modifications, the accuracy would drop. However, if the total FLOPs are aligned to be similar for the ResNet50 and ResNet50 w/ PConv (e.g., by increasing the network width), the ResNet50 w/ PConv would have higher accuracy (+0.6% in my experiment for 90 epochs' training).