1. Institute of Communications Engineering, Ulm University, 89081 Ulm, Germany
2. Ubiquitous Computing Systems Laboratory, Nara Institute of Science and Technology, Ikoma 630-0192, Nara, Japan
3. Human-Centered Artificial Intelligence, University of Augsburg, 86159 Augsburg, Germany
4. Natural Language Generation and Dialogue Systems, University of Bamberg, 96050 Bamberg, Germany