“…), has been extensively studied in the past decade and attracted increasing attention from academia and industry [38,30,61,62,63]. ELM theories demonstrate that hidden neurons can be set randomly in many applications, including clustering, feature learning, regression, and classification [64,45,65,66]. Many variants of the ELM have been proposed in the last decade, and most of our work concentrate on the early ELM (called "basic ELM" here), explore and enhance its abilities of image classification and feature learning.…”