NoBis: A crowd monitoring service against COVID-19

This paper presents NoBis, a new service for monitoring the crowding of indoor spaces in the COVID-19 era. The name links the concept of “We” to the desire of not having an “Encore” of the first lockdown experienced worldwide in March 2020. NoBis is a REST-based web application which provides tools for allowing “Referents” to manage places to be monitored and, at the same time, for allowing end users to consult in real time the crowding state related to monitored places. The entire platform is based on the use of QR codes which users scan each time they enter (Check-in operation) and exit (Check-out operation) from a monitored place. NoBis is implemented in JavaScript both for the front end, with the help of libraries such as JQuery, and the back-end, through the use of Node.js. This choice allowed for a more agile and”lightweight” development, in accordance with the time constraints required by the project. During the month of September 2020 a preliminary testing phase took place at the Department of Information Engineering of the University of Padova. NoBis represents a valuable tool to monitor crowding in libraries and similar enclosed places accessible to the public.