Number of transplants (with) and without the proposed post-processing step for various KPD pool sizes.

<p>Number of transplants (with) and without the proposed post-processing step for various KPD pool sizes.</p

Elite individual’s fitness per iteration.

<p>Elite individual’s fitness per iteration.</p

The composition of a resulting optimal solution.

<p>(a) IP-KPD, (b) Proposed, (c) GA-KPD.</p

Compatibility information with respect to the pool size, n.

<p>Compatibility information with respect to the pool size, n.</p

Parameter settings for GA-KPD and the proposed method.

<p>Parameter settings for GA-KPD and the proposed method.</p

Two-cycle exchange.

<p> blood type is incompatible with his donor , the incompatibility is represented by dotted lines. The two incompatible pairs can swap their kidneys as illustrated by solid lines.</p

A flow chart of the proposed ALO algorithm for kidney exchanges.

<p>A flow chart of the proposed ALO algorithm for kidney exchanges.</p

A NEAD exchange graph.

<p>A chain starts with an altruistic donor and ends with a bridge donor assigned to the first compatible patient on the next round.</p

A directed graph representation of three-cycle exchange.

<p>The solid arcs represent the potential swaps, i.e. the two pairs (,) and (,) can exchange their kidneys.</p

Transplants returned by all applied methods.

<p>(a) Pool size = 30, (b) Pool size = 40, (c) Pool size = 50, (d) Pool size = 75, (e) Pool size = 100, (f) Pool size = 200.</p