Ronald Rousseau

KU Leuven | ku leuven · Department of Managerial Economics, Strategy and Innovation (MSI)

Objective. This study investigated the relation between the degree sequences of trees and the majorization order. Design/Methodology/Approach. The majorization technique was employed in accordance with the tenets of Muirhead’s theorem. Results. In this study, we proved a theorem that provides a necessary and sufficient condition for degree sequence...

In this investigation we study a family of networks, called spiders, which covers a range of networks going from chains to complete graphs. These spiders are characterized by three parameters: the number of nodes in the core, the number of legs at each core node, and the length of these legs. Keeping two of the three parameters constant we investig...

We introduce and define three types of small worlds: small worlds based on the diameter of the network (SWD), those based on the average geodesic distance between nodes (SWA), and those based on the median geodesic distance (SWMd). These types of networks are defined as limiting properties of sequences of sets. We show the exact relation between th...

We investigate the relation between degree sequences of trees and the majorization order using the Muirhead theorem. In this way, we prove a theorem that provides a necessary and sufficient condition for delta sequences of trees to be comparable in the majorization order. Although our investigation is largely theoretical, our study contributes to a...

We find out which older publications (defined here as published before 1991) are nowadays, i.e. during the period [2013–2022], the most cited in leading bibliometric journals. It is found that Small’s article on co-citation analysis is the most-cited one in these journals, followed by Garfield’s “Citation Analysis as a Tool in Journal Evaluation” a...

In this opinion paper, we introduce the expressions of dominant terminology and dominant term in the quantitative studies of science in analogy to the notion of dominant design in product development and innovation.

Derek J. de Solla Price viewed science as a complex system and anticipated that the science of science can be developed via an analogy to thermodynamics. The main point of this article is to show a direct equivalence between a thermodynamic framework and the classical theory of evenness. It illustrates how thermodynamically inspired terms can lead...

Inspired by the Lorenz curve for evenness or concentration, and the corresponding axioms, we construct a theory leading to the notion of global impact. In this theory, we construct a relation that plays the role of the Lorenz dominance order for evenness or concentration theory. The notion of global impact that we obtain is such that well-known glo...

Among all Derek de Solla Price Memorial Medal awardees, the late Loet Leydesdorff has the highest h-index.

In previous work, we introduced the notion of an impact bundle, showing how e.g., the h-index and the g-index can lead to such a bundle. Here we extend the set of impact bundles by a new impact bundle, based on the Zhang e-index. It is, moreover, shown that some other plausible definitions do not lead to an impact bundle.

The concept of impact is one of the most important concepts in informetrics. It is here studied mathematically. We first fix a topic for which we want to find influential objects such as authors or journals, and their production, such as publications generating citations. These objects are then said to have a certain degree of impact. We work on th...

We extend the discrete majorization theory by working with non-normalized Lorenz curves. Then we prove two generalizations of the Muirhead theorem. These not only use elementary transfers but also local increases. Together these operations are described as elementary impact increases. The first generalization shows that if an array X is dominated,...

We present a continuous theory of global impact measures. Such measures combine inequality (like the Lorenz theory) with productivity, leading to the notion of global impact and its measurement.

We show that the h-index, g-index, ψ-index, and p-index, are related through the inequalities: h ≤ p ≤ g ≤ ψ. Moreover, this relation is proved theoretically in the mathematical framework of Lotkaian informetrics and is verified empirically by using two datasets from the Web of Science in the fields of electrochemistry and gerontology. For quantify...

Purpose We aim to extend our investigations related to the Relative Intensity of Collaboration (RIC) indicator, by constructing a confidence interval for the obtained values. Design/methodology/approach We use Mantel-Haenszel statistics as applied recently by Smolinsky, Klingenberg, and Marx. Findings We obtain confidence intervals for the RIC in...

This article aims to add to the body of indicators used to study collaboration in science. We propose a new indicator to measure balance in collaboration (BIC) which is based on the Gini evenness index for a weighted Lorenz curve. The new indicator of balance builds upon and extends the use of, our previously introduced indicator of relative intens...

The purpose of this study is to explore if elite scientists play a key role in the genesis of transformative research. As there exist different types of transformative research, this paper focuses on one type of work, i.e. under-cited influential work,referred to as “sparking” articles. A comparative study between the h-indices of authors citing No...

First, we introduce the notion of a strong impact measure. This notion is based on the corresponding notion of a strong impact curve. Next, this notion is generalized through the notion of impact bundles. Superficially the corresponding theory bears some resemblance and was inspired by the theory of inequality (concentration, diversity) but it diff...

After a short introduction to her life and work, we construct Rosalind Franklin’s citation environment in the sense of Howard White. This environment consists of four groups of authors related to Franklin: her co-authors, those cited by Franklin, those co-cited with Franklin, and those citing Franklin. We further found two of her articles that can...

In this contribution, we conduct a multi-angular analysis of the interdisciplinarity of Nobel Prize winning research compared to non-Nobel Prize winning articles, based on a large data set. Here interdisciplinarity is measured by the diversity of references, using two true diversity indicators. Articles mentioned by the Nobel Prize committee in Phy...

Parametrized systems of evaluation measures derived from the h-index, the g-index and other informetric measures are applied to sets of functions, denoted as Z. This results in a new class of general function systems, referred to as Complete Evaluation Systems (CESes). Two different functions in a CES can never have the same value for every value o...

In research fields like informetrics or patent research, international comparisons are part of their core business. One class of measures used in such comparisons consists of affinity indices. Here, relations of shares are calculated to express the relation between two actors X and Y. Even though this group of affinity indices already has many memb...

We provide details about how to calculate mutual information in the Triple Helix context. The underlying entropy measures are described as functions working on empirical discrete stochastic variables. The associated Triple Helix transformation is shown to be nonlinear.

Purpose This article aims to determine the percentage of “Sparking” articles among the work of this year’s Nobel Prize winners in medicine, physics, and chemistry. Design/methodology/approach We focus on under-cited influential research among the key publications as mentioned by the Nobel Prize Committee for the 2020 Noble Prize laureates. Specifi...

The Yule-Simpson paradox refers to the fact that outcomes of comparisons between groups are reversed when groups are combined. Using Essential Sciences Indicators, a part of InCites (Clarivate), data for countries, it is shown that although the Yule-Simpson phenomenon in citation analysis and research evaluation is not common, it isn’t extremely ra...

This study uses Google Trends data to analyze the impact of the main events in the Tour de France 2019 on cyclists’ online popularity in 12 countries and at a global scale. A fixed effects panel model revealed a strong own-country preference. While online popularity increased with the duration of the Tour, race incidents strongly influenced online...

Bibliometric indicators and bibliometric techniques have been used in the domains of business and economics (BE) in the context of network studies and the evaluation of universities, journals and researchers, among other purposes. Using a strengths, weaknesses, opportunities and threats analysis as a general framework, we present an overview of the...

In this article, we try to find out what Vasiliy Nalimov and Zinaida Mul’chenko exactly wrote in their famous book Naukometriya, the Study of the Development of Science as an Information Process (1969). Afterward, the term Naukometriya became known in the West as Scientometrics. It is often mentioned that Nalimov invented the term scientometrics, u...

We describe how to obtain the data, from the Web of Science, to calculate the RIC indicator. Besides the main application, based on collaboration links, we also show how to obtain data for a version of the RIC based on collaborated publications.

Purpose In this contribution we provide two new co-authorship indicators based on fractional counting. Design/methodology/approach Based on the idea of fractional counting we reflect on what should be an acceptable indicator for co-authorship between two entities. From this reflection we propose an indicator, the co-authorship score, denoted as cs...

This article provides an overview of the development of the h-index formalism. We begin with the original formulation as provided by Hirsch and move on to the latest versions. In this we show how the h-index formalism has evolved over time. Lesser known versions, in particular the continuous version of the h-index is brought to the front. We also d...

In this note, we explain how to find the yearly numbers of items in Clarivate's Web of Science (WoS) and its sub-databases. As a result, we find that the WoS Core Collection grows exponentially during the period 1990-2019. We check and confirm that a simultaneous search at different locations leads to exactly the same results.

We provide a short overview of the science of team science (SciTS). Starting from the notion of a scientific team, we move to interdisciplinary studies and finally the Science of Team Science itself. We describe the main areas of research in this field. As co-authorship networks may grow over time, which can lead to a future “global brain”, underst...

In this contribution, we consider the problem of finding the minimal Euclidean distance between a given converging decreasing one-dimensional array X in (R+)∞ and arrays of the form Aa=a,a,…,a, 0,0, …a times, with a being a natural number. We find a complete, if not always unique, solution. Our contribution illustrates how a formalism derived in th...

This article highlights the importance of using polar coordinates when studying functions, in particular in relation to generalized h-type indices. Concretely, generalized h-type indices are essentially polar coordinates. This observation ties informetric ideas to standard mathematics. This article is essentially meant to provide tools for further...

Purpose Providing an overview of types of citation curves. Design/methodology/approach The terms citation curves or citation graphs are made explicit. Findings A framework for the study of diachronous (and synchronous) citation curves is proposed. Research limitations No new practical applications are given. Practical implications This short no...

A dynamic quantitative theory and measurement of power or dominance structures are proposed. Such power structures are represented as directed networks. A graph somewhat similar to the Lorenz curve for inequality measurement is introduced. The changes in the graph resulting from network dynamics are studied. Dynamics are operationalized in terms of...

It is shown that the terms balassa index , revealed comparative advantage, and activity index refer to the same mathematical formula.

In this contribution we introduce the notion of a measure (or indicator) of linear type. Combining ideas related to power functions, in particular Zipf’s function, and h-type indices, we come to a novel characterization of general power functions and Zipf’s functions.

The objective of this paper is to show that the already existing h((3)) indicator, designed after the h-index and Kosmulski's h((2))-index, has some advantages with respect to the classical h- or h((2))-indices, when it comes to academic journal evaluation. The h((3))-index for journals is defined as the largest natural number h(3) such that the fi...

We study the array of partial sums, Px, of a given array X in terms of its h-type indices. Concretely, we show that h(Px) can be described in terms of the Lorenz curve of the array X and obtain a relation between the sum of the components of Px and the Gini index of X. Moreover, we obtain sharp lower and upper bounds for h-type indices of Px.

In this article we solve a minimum problem involving step functions. The solution of this problem leads to an investigation into generalized h- and g-indices. This minimum problem and the related generalized h- and g-indices are studied in a general context of decreasing differentiable functions as well as in the specific case of Lotkaian informetr...

In this feasibility study, the impact of academic research from social sciences and humanities on technological innovation is explored through a study of citations patterns of journal articles in patents. Specifically we focus on citations of journals from the field of environmental economics in patents included in an American patent database (USPT...

We develop and propose a new counting method at the aggregate level for contributions to scientific publications called modified fractional counting (MFC). We show that, compared to traditional complete-normalized fractional counting, it eliminates the extreme differences in contributions over time that otherwise occur between scientists that mainl...

We propose a new method for computing the bibliographic coupling strength between two documents. This new method is based on the TF-IDF formula from the field of information retrieval. It is shown that this formula is a valid alternative for the original formula introduced by Kessler and is, from a probabilistic point of view, a correction of the V...

We obtain a remarkable geometric relation between the Lorenz curve of a non-negative, continuous, decreasing function Z(r) and the h-index of integrals defined over a subinterval of the domain of Z(r). This result leads to a new geometric interpretation of the h-index of Z.

Purpose To show for which publication-citation arrays h-type indices are equal and to reconsider rational h-type indices. Results for these research questions fill some gaps in existing basic knowledge about h-type indices. Design/methodology/approach The results and introduction of new indicators are based on well-known definitions. Findings The...

In this study we investigate if articles suffering delayed recognition can at the same time be under‐cited influential articles. Theoretically these two types of articles are independent, in the sense that suffering delayed recognition depends on the number and time distribution of received citations, while being an under‐cited influential article...

Starting from the notion of h-type indices for infinite sequences we investigate if these indices satisfy natural inequalities related to the arithmetic, the geometric and the harmonic mean. If f denotes an h-type index, such as the h- or the g-index, then we investigate inequalities such as min(f(X),f(Y)) ≤ f((X + Y)/2) ≤ max(f(X), f(Y)). We furth...

In this article I start an investigation of the pros and cons of the Australian and New Zealand Fields of Research (FoR) codes . The main reason for doing this is the expectation that, following its use in the database Dimensions, these codes will show an increased use.

Purpose New developments in the study of delayed recognition are discussed. Design/methodology/approach Based on these new developments a method is proposed to characterize delayed recognition as a fuzzy concept. Findings A benchmark value of 0.333 corresponding with linear growth is obtained. Moreover, a case is discovered in which an expert fou...

Scientific journals are ordered by their impact factor while countries, institutions or researchers can be ranked by their scientific production, impact or by other simple or composite indicators as in the case of university rankings. In this paper, the theoretical framework proposed in Criado, R., Garcia, E., Pedroche, F. & Romance, M. (2013). A n...

In this contribution, we develop a new approach to explore the process of knowledge transition from discovery-oriented science to technological fields, via applications-oriented research, including a mediator set. This trajectory is referred to as the D-A-T trajectory. It is shown how it can be constructed and measures are proposed to characterize...

The purpose of this paper is to describe an under-recognized meta-table introduced by Nancy Clark. Although lowly cited the usefulness of this table as a structured set of metadata is shown. Clark’s introduction of the table tamer is summarized and illustrated. As a meta-table, Clark’s Table tamer provides a concise summary of the contents as well...

Software programs are among the most important tools in data‐driven research. The popularity of well‐known packages and corresponding large numbers of citations received bear testimony of the contribution of scientific software to academic research. Yet software is not generally recognized as an academic outcome. In this study, a usage‐based model...

In this short note we recall the history and definition of the repeat rate, also known as the Hirschman–Herfindahl index or as the Simpson index, and show that its generalization to a measure that includes disparity between items, known as the Rao-Stirling index, or a monotone transformation of it, is an acceptable diversity measure which, however,...

Purpose In this contribution we continue our investigations related to the activity index ( AI ) and its formal analogs. We try to replace the AI by an indicator which is better suited for policy applications. Design/methodology/approach We point out that fluctuations in the value of the AI for a given country and domain are never the result of th...

In this contribution we study four examples of hibernators and their citation relation s with their awakeners. We, moreover, introduce the notion of authoritative citers, a group of articles that, like the awakener, cite the hibernator and play similar roles as the awakener. Yet, the interplay between the hibernator, the awakener and authoritative...

In this contribution we perform an elementary citation analysis related to the blockchain technology, the technology underlying the bitcoin currency. In order to sketch the framework we first provide a basic introduction to this technology. More importantly we point out that this technology has the potential to transform ownership, traceability, in...

We explain how to determine automatically the e-mail address of the corresponding author in a Web of Science record. Next, we distinguish two types of e-mails used by corresponding authors of academic papers: institutional e-mails and non-institutional ones. We investigate differences between papers with an institutional e-mail address and those wi...

This study has a double purpose: a fact-finding one and a methodological one. The fact-finding part consists of two elements. First we study the growth of the hepatitis literature in the World and in particular in India over the latest 30 years (1986–2015). Second we determine the priority given to hepatitis studies in a number of leading countries...

Publication citation-based research evaluation, even if only in support of peer review, is not everywhere, on every level, or for everyone suitable, because of differences in scientific research, patterns of research output, stages of scientific evolution, and merits-scientific or societal-of scientific results.

In this article we continue our study of power structures, providing further examples of dominance structure in a directed acyclic network. We calculate the D-measure, a measure expressing the degree of dominance in a network, when nodes are added to an existing simple network. This was done for "moving from a hand to a line", and for a citation ne...

In this study we investigate if sleeping beauties, also known as articles suffering delayed recognition, can at the same time be under-cited influential articles. Theoretically these two types of articles are independent, in the sense that being a sleeping beauty depends on the number and time distribution of received citations, while being an unde...

We show that Eugene Garfield published articles which are neither highly cited nor completely ignored, but had a clear influence on subsequent citation generations. More precisely, we found ten articles that are under-cited influential publications, in the sense given to this expression in our earlier work. By publishing this investigation we hope...

This article compares six informetric approaches to determine cognitive distances between the publications of panel members and those of research groups in discipline-specific research evaluation. We used data collected in the framework of six completed research evaluations from the period 2009-2014 at the University of Antwerp as a test case. We d...

While general publication practices clearly differ between disciplines, knowledge about scientometric indicators can also greatly vary. The observed heterogeneity in bibliometric knowledge inspired us to define the concept of 'metric-wiseness' for researchers. Being metric-wise can lead to an advantage for knowledgeable researchers over uninformed...

Although heterogeneous networks are ubiquitous, a precise definition is lacking, in our opinion. We submit a definition of network heterogeneity and elaborate on a resulting approach to its measurement. This measure is denoted as HE. As an illustration HE is applied to examples from the fields of informetrics and neurosciences. Yet, it is pointed o...

We study the problem of determining the cognitive distance between the publication portfolios of two units. In this article we provide a systematic overview of five different methods (a benchmark, Euclidean distance approach, distance between barycenters in two and in three dimensions, distance between similarity-adapted publication vectors, and we...

In this contribution, which builds on and develops a study that was published more than 10 years ago, we address the role of the Chinese Key Labs (KLs) in the international and national scientific arena. We give a short overview of the position of KLs in China, including their budget and manpower. Based on large numbers of Chinese publications obta...

The scientific foundation for the criticism on the use of the Journal Impact Factor (JIF) in evaluations of individual researchers and their publications was laid between 1989 and 1997 in a series of articles by Per O. Seglen. His basic work has since influenced initiatives such as the San Francisco Declaration on Research Assessment (DORA), the Le...

It is shown that the use of Flanders’ regional bibliographic information system in a performance-based research funding system corresponds to a large extent with the principles of the Leiden Manifesto. Yet, it is argued that there is still room for improvement. We offer this Flemish perspective on the Leiden Manifesto as a suggestion to colleagues...

In this contribution we study partial orders in the set of zero-sum arrays. Concretely, these partial orders relate to local and global hierarchy and dominance theories. The exact relation between hierarchy and dominance curves is explained. Based on this investigation we design a new approach for measuring dominance or stated otherwise, power stru...

In this submission we introduce the notion of under-cited influential publications and show that these publications are like “wake-up switches” for significant follow-up research. To be considered an under-cited influential article we require an article to meet three requirements. One is on the level of received number of citations (first generatio...