量子衍生差分进化算法的设计与实现

Design and Implementation of Quantum-inspired Differential Evolution Algorithm

为提高差分进化算法的优化性能,从研究差分进化算法的实现机制入手,提出将差分策略与量子比特在Bloch球面的绕轴旋转相融合的新思想。个体采用基于Bloch球面描述的量子比特编码,采用差分策略计算当前个体上量子比特的旋转角度,采用向量积理论构造旋转轴,采用泡利矩阵构造旋转矩阵,以当前最优个体上相应量子比特为目标,在Bloch球面上沿旋转轴向目标比特旋转。采用Hadamard门实现个体变异。函数极小值优化的仿真结果表明,所提方法单步迭代的平均时间约为普通差分进化算法的13倍。当限定步数相同时,优化结果约为普通差分进化算法的0.3倍,当运行时间相同时,优化结果约为普通差分进化算法的0.4倍。从而表明所提算法计算效率降低,但寻优能力明显提高,整体优化性能优于原算法。

To enhance the optimization performance of differential evolution algorithm, by studying the implementation mechanism of differential evolution algorithm, a new idea of incorporating differential strategy and rotation of qubits in the Bloch sphere is proposed in this paper. In the proposed approach, the individuals are encoded by qubits described on Bloch sphere, and the rotation angles of qubits in current individual are obtained by differential strategy. The axis of rotation is designed by using vector product theory, and the rotation matrixes are constructed by using Pauli matrixes. Taking the corresponding qubits in current best individual as targets, the qubits in current individual are rotated to the target qubits about the rotation axis on the Bloch sphere. The Hadamard gates are used to mutate individuals. The simulation results of optimizing the minimum value of functions indicate that, for an iterative step, the average time of the proposed approach is 13 times as long as that of the classical differential evolution algorithm. When the same limited steps are applied in two approaches, the average optimization result of the proposed approach is 0.3 times as great as that of the classical differential evolution algorithm ; when the same running time is applied in two approaches, the average optimization result of the proposed approach is 0.4 times as great as that of the classical differential evolution algorithm. These results suggest that the proposed approach is inefficient in computational ability; however, it is obviously efficient in optimization ability, and the overall optimization performance is better than the classical differential evolution algorithm.