Norm of node representation z

[fatcatZF]

Since the dot product similarity z_uz_v can be affected by the norm of the node representation vectors; i.e., z_uz_v = cos<z_u,z_v>|z_u||z_v|. If You use dot product to approximate the (cosine) similarity of the 2 vectors z_u and z_v, how can you make sure that the 2 vectors have similar norms?