**Author details**

Miguel A. González Hernández<sup>1</sup> , Ana I. Moreno López<sup>1</sup> , Artur A. Jarzabek<sup>1</sup> , José M. Perales Perales<sup>1</sup> , Yuliang Wu2 and Sun Xiaoxiao2

1 Polytechnic University of Madrid, Spain

2 Beijing Institute of Technology, China

### **References**

