This paper proposes a novel data classification framework. combining sparse auto-encoders (SAEs) and a post-processing system consisting of a linear system model relying on Particle Swarm Optimization (PSO) algorithm. All the sensitive and high-level features are extracted by using the first auto-encoder which is wired to the second auto-encoder. followed by a Softmax function layer t... https://www.unitedssports.shop/product-category/volleyball-balls-competition/