Entropy in Machine Learning Applications

The aim of this reprint is to inform readers of the latest developments in methods and applications of machine learning and deep learning in certain fields, including the following: a semantically enhanced social network user alignment algorithm to perform user alignment; a congestion control mechanism based on deep reinforcement learning; problem solving involving low-accuracy, large-entropy perturbation; information loss in the calculation process of fault feature parameters of rolling bearing; a hybrid recommendation model combining autoencoder and latent feature analysis techniques; extracting knowledge from published papers and reports on drilling to guide the control of wells; an improved binary golden jackal optimization algorithm; water quality prediction based on machine learning and comprehensive weighting methods; redundancy of crossentropy calculation in deep learning of classifiers; automatic vertebral rotation angle measurement of vertebrae using an improved transformer network; defining suitable graph contrastive learning through applications of graph information bottlenecks and structural entropy theories; and a comprehensive examination of the latest advancements in deep learning methodologies. We hope that the papers in this Special Issue can contribute to promoting and facilitating the further research and application of machine learning methods.