Q-measures are network indicators that gauge a node's brokerage role between different groups in the network. Previous studies have focused on their definition for different network types and their practical application. Little attention has, however, been paid to their theoretical and...

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...

A correction is provided for the proof of a theorem announced in (Rousseau et al., 2013). We show, moreover, that in a network subdivided into three or more subgroups there is at most one node with global Q-measure equal to one. In case there are two subgroups then it is possible to have two...

This study examines collaboration dynamics with the goal to predict and recommend collaborations starting from the current topology. Author-, institution-, and country-level collaboration networks are constructed using a ten-year data set on library and information science publications....

This paper investigates directional returns to scale (RTS) and illustrates this approach by studying biological institutes of the Chinese Academy of Sciences (CAS). Using the following input–output indicators are proposed: senior professional and technical staffs, middle level and junior...

We show that usually the influence on the Hirsch index of missing highly cited articles is much smaller than the number of missing articles. This statement is shown by a combinatorial argument. We further show, by using a continuous power law model, that the influence of missing articles is...

The structure of different types of time series in citation analysis is revealed, using an adapted form of the Frandsen–Rousseau notation. Special cases where this approach can be used include time series of impact factors and time series of h-indices, or h-type indices. This leads to a tool...

Basic publication–citation matrices are used to calculate informetric indicators such as journal impact factors or R-sequences. Transforming these publication–citation matrices clarifies the construction of other indicators. In this article, some transformations are highlighted together with...

Five ratios RH, RT, SH, ST and SZ derived from the three-part division of a set of sources in h-core, h-tail and uncited sources are defined. Dynamic changes in the three independent ratios RH, SH and SZ are studied for six selected topics. Data about these topics are obtained from the Web of...

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...