If this code is helpful for you, please cite this paper: Sihong Zhou, Jun Qiu, Cheng Zhang, Yanming Guo, Qinghui Pan, Qian Zhou, Yong Shuai, Fast design and optimization method for an ultra-wideband perfect absorber based on artificial neural network acceleration, International Journal of Thermal Sciences, Volume 179, 2022, 107680, ISSN 1290-0729, https://doi.org/10.1016/j.ijthermalsci.2022.107680. (https://www.sciencedirect.com/science/article/pii/S1290072922002162)