On December 23, John Crittenden, president of Brookbell School of Sustainable Development, Georgia Institute of Technology, gave the 7^th academic lecture of BJAST Lecture Hall to scientific and technical personnel of our BJAST at invitation. Shao Jinwen, vice president, presided over the lecture.

Professor John Crittenden is an academician of the National Academy of Engineering of the US, a foreign academician of the Chinese Academy of Engineering and a winner of the Chinese Government Friendship Award 2019. He gave an excellent lecture titled as "Big Technologies - Developing Sustainable Urban Infrastructure to Respond to Great Challenges". Based on the concept of urban development and sustainable development, he described how to create a sustainable and resilient infrastructure ecosystem, introduced the technology integration in the fields of transportation, energy, water, air and health and the applications of big technologies with vivid cases, and in the end mainly introduced the "Digital Twin" application platform, one of his major research outcome. As the whole lecture was either excellent and vivid, participants actively engaged in exchanges with John Crittenden.