This book highlights the recent research on soft computing, pattern recognition, nature-inspired computing and their various practical applications. It presents 53 selected papers from the 13th International Conference on Soft Computing and Pattern Recognition (SoCPaR 2021) and 11 papers from the 13th World Congress on Nature and Biologically Inspired Computing (NaBIC 2021), which was held online, from December 15 to 17, 2021. A premier conference in the field of soft computing, artificial intelligence and machine learning applications, SoCPaR-NaBIC 2021 brought together researchers, engineers and practitioners whose work involves intelligent systems, network security and their applications in industry. Including contributions by authors from over 20 countries, the book offers a valuable reference guide for all researchers, students and practitioners in the fields of computer science and engineering.