  This paper presents an Iterated Tabu Search algorithm (denoted by ITS-PUCC)
for solving the problem of Packing Unequal Circles in a Circle. The algorithm
exploits the continuous and combinatorial nature of the unequal circles packing
problem. It uses a continuous local optimization method to generate locally
optimal packings. Meanwhile, it builds a neighborhood structure on the set of
local minimum via two appropriate perturbation moves and integrates two
combinatorial optimization methods, Tabu Search and Iterated Local Search, to
systematically search for good local minima. Computational experiments on two
sets of widely-used test instances prove its effectiveness and efficiency. For
the first set of 46 instances coming from the famous circle packing contest and
the second set of 24 instances widely used in the literature, the algorithm is
able to discover respectively 14 and 16 better solutions than the previous
best-known records.
