ResNet perserving ratio

Following similar setting as Filter pruning [31], we keep 70% channels for sensitive residual blocks (res5 and blocks close to the position where spatial size change, e.g. res3a,res3d). As for other blocks, we keep 30% channels. With multi-branch enhancement, we prune branch2a more aggressively within each residual block. The preserving channels ratios for branch2a,branch2b,branch2c is 2 : 4 : 3 (e.g., Given 30%, we keep 40%, 80%, 60% respectively).

how do we come up with 40%, 80%, 60%?

Given 2 : 4 : 3 preserving ratio for branch2a,branch2b,branch2c, we define them as 2x,4x,3x respectively.
the original complexity for a block ratio is 1/4:9/16:1/4
Then 30%*(1/4+9/16+1/4) = 1/4*2x*4x+ 9/16*4x*3x + 1/4*3x
Solve this, we got x=20%
Then we got preserving ratio 40%, 80%, 60% for branch2a,branch2b,branch2c