Proceedings of International Conference on Sustainable Expert Systems : ICSES 2020 Captcha based Defense Mechanism to Prevent DoS Attacks Application of Rules & Authorisation Key For Secured Online Training A Survey Factors Affecting The Online Travel Purchasing Decision: An Integration of Fuzzy Logic Theory Bidirectional Battery Charger for Electric Vehicle Healthy Sri Lankan Meal Planner with Evolutionary Computing Approach Pattern Matching Compression Algorithm for DNA Sequences Deep Learning based Bluetooth controlled Robot for Automated Object Classification Machine Learning Based Real Time Traffic Accident Detection. This book includes papers on intelligent expert systems and sustainability applications in the areas of data science image processing wireless communication risk assessment healthcare intelligent social network mining and energy. The recent growth of sustainability leads to a progressively new era of computing where its design and deployment leverages significant impact on the intelligent systems research. Moreover the sustainability technologies can be effectively used in the progressive deployment of various network enabled technologies like intelligent sensors smart cities wearable technologies robotics web applications and other such Internet technologies. The thrust of this book is to publish the state of the art research articles that deals with the design development implementation and testing of the intelligent expert systems and also to provide an overview of the sustainable management of these systems. .