A modified algorithm for the quadratic assignment problem using chaotic-neuro-dynamics for VLSI implementation

The quadratic assignment problem (QAP) is one of the NP-hard combinatorial optimization problems, which is very difficult to solve. The tabu search technique, one of the various heuristic methods for the QAP, has been implemented in a neural network form with chaotic dynamics. In order to achieve a high-speed massively parallel solution of the QAP, a mixed analog/digital integrated circuit implementation of the system is mandatory. However, the algorithm in Hasegawa et al. (1997) cannot be implemented with IC technology as it is. Therefore, the algorithm is modified to be suitable for the analog IC implementation in this paper. The performance of the modified algorithm is investigated with numerical simulations. The circuit characteristics obtained from a prototype chip is extensively used in the simulations.