Collaboration can be described using layered systems such as the article–author–institute–country structure. These structures can be considered ‘cascades’ or ‘chains’ of bipartite networks. We introduce a framework for characterizing and studying the intensity of collaboration...

We introduce layered systems such as the citations–citing authors–citing institutes–citing countries one. Diffusion of scientific ideas flows through such layered systems. Our contribution contains three main topics: a fractional counting system for the number of different units in a...