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...

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...

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...

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...

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...

We introduce the h-degree of a node as a basic indicator for weighted networks. The h-degree (dh) of a node is the number dh if this node has at least dh links with other nodes and the strength of each of these links is greater than or equal to dh. Based on the notion of h-degree other notions...

The definitions of the rational and real-valued variants of the h-index and g-index are reviewed. It is shown how they can be obtained both graphically and by calculation. Formulae are derived expressing the exact relations between the h-variants and between the g-variants. Subsequently these...

Recently Woeginger [Woeginger, G. H. (2008-a). An axiomatic characterization for the Hirsch-index. Mathematical Social Sciences. An axiomatic analysis of Egghe's g-index. Journal of Informetrics] introduced a set of axioms for scientific impact measures. These lead to a characterization of the...