Review: Efficiency of PIEOs over PIFOs

[KabirSamsi]

See the discussion in #12.

The paper by Elbediwy et al discusses how PIEOs give us more efficiency and stronger flow handling ability than PIFOs do (see in particular section 2.III). As a follow-up from the 7/1 meeting, this issue serves as a reminder to investigate this claim and the efficiency trade-off between PIFOs and PIEOs more closely.