*Article* **Memetic Strategy of Particle Swarm Optimization for One-Dimensional Magnetotelluric Inversions**

**Ruiheng Li 1,2, Lei Gao 1,2, Nian Yu 1,2,\*, Jianhua Li 3,\*, Yang Liu 1,2, Enci Wang 1,2 and Xiao Feng 4**


**Abstract:** The heuristic algorithm represented by particle swarm optimization (PSO) is an effective tool for addressing serious nonlinearity in one-dimensional magnetotelluric (MT) inversions. PSO has the shortcomings of insufficient population diversity and a lack of coordination between individual cognition and social cognition in the process of optimization. Based on PSO, we propose a new memetic strategy, which firstly selectively enhances the diversity of the population in evolutionary iterations through reverse learning and gene mutation mechanisms. Then, dynamic inertia weights and cognitive attraction coefficients are designed through sine-cosine mapping to balance individual cognition and social cognition in the optimization process and to integrate previous experience into the evolutionary process. This improves convergence and the ability to escape from local extremes in the optimization process. The memetic strategy passes the noise resistance test and an actual MT data test. The results show that the memetic strategy increases the convergence speed in the PSO optimization process, and the inversion accuracy is also greatly improved.

**Keywords:** particle swarm optimization; magnetotelluric; one-dimensional inversions; geoelectric model; optimization problem
