Towards closed-loop automation in 5g open ran: Coupling an open-source simulator with xapps - Theofanis Karamplias; Sotirios T. Spantideas; Anastasios E. Giannopoulos; Gkonis, Panagiotis; Kapsalis, Nikolaos; Trakadas, Panagiotis (2022 Joint European Conference on Networks and Communications & 6G Summit (EuCNC/6G Summit), 2022)