original             : torch.Size([1, 512, 28, 28])no projection        : torch.Size([1, 512, 28, 28])after conv0-bn0-relu : torch.Size([1, 256, 28, 28])    #(1)after conv1-bn1-relu : torch.Size([1, 256, 28, 28])after conv2-bn2      : torch.Size([1, 512, 28, 28])    #(2)after semodule       : torch.Size([1, 512, 28, 28])    #(3)after summation      : torch.Size([1, 512, 28, 28])    #(4)