A degree centrality in multi-layered social network
  Multi-layered social networks reflect complex relationships existing in modern interconnected IT systems. In such a network each pair of nodes may be linked by many edges that correspond to different communication or collaboration user activities. Multi-layered degree centrality for multi-layered social networks is presented in the paper. Experimental studies were carried out on data collected from the real Web 2.0 site. The multi-layered social network extracted from this data consists of ten distinct layers and the network analysis was performed for different degree centralities measures. 
Piotr Br\'odka, Krzysztof Skibicki, Przemys{\l}aw Kazienko, Katarzyna   Musia{\l}
cs.SI physics.soc-ph