1. Heinz Nixdorf Institut, Paderborn University, Paderborn, Germany
2. Paderborn University, Paderborn, DC, Germany
3. Delft University of Technology, Delft, Netherlands
4. INESC-ID and IST, University of Lisbon, Lisbon, Portugal
5. Heinz Nixdorf Institut & Fraunhofer IEM, Paderborn University, Paderborn, Germany