This document discusses Internet of Things (IoT) reference architectures and case studies. It presents a cognitive loop model of sense-learn-operate-act and diagrams showing people, environment, things, edge/communication networks, data/applications. A specific case study describes a cloud-based smart fridge monitoring solution that allows bidirectional communication with sensors/actuators for data collection, remote asset management, and analytics. The document advocates applying systems engineering principles to IoT design and highlights security as a key challenge that vendors are working to address.