  We revisit the design of cloaks, without resorting to any geometric
transform. Cancellation techniques and anomalous resonances have been applied
for this purpose. Instead of a deductive reasoning, we propose a novel
mono-objective optimization algorithm, namely a ternary grey wolf algorithm,
and we adapt a bi-objective optimization algorithm. Firstly, the proposed
chaotic ternary grey wolf algorithm searches three-valued spaces for all
permittivity values in the cloak while minimizing the summation of a protection
criterion and an invisibility criterion. Secondly, a bi-objective genetic
algorithm is adapted to find pairs of optimal values of invisibility and
protection.
