IoT as a Service 4th EAI International Conference, IoTaaS 2018, Xi'an, China, November 17-18, 2018, Proceedings - Li, Bo; Li, Bo; Yang, Mao; Yang, Mao; Yuan, Hui; Yuan, Hui; Yan, Zhongjiang; Yan, Zhongjiang (Springer International Publishing : Imprint: Springer, 2019)