Nondestructive Evaluation of Thermal Barrier Coatings Thickness Using Terahertz Technique Combined with PCA–GA–ELM Algorithm. - Yuan, Baohan; Wang, Weize; Ye, Dongdong; Zhang, Zhenghao; Fang, Huanjie; Yang, Ting; Wang, Yihao; Zhong, Shuncong (Coatings (2079-6412), 2022)