On some new bibliometric applications of statistics related to the h-index

In this paper some new fields of application of Hirsch-related statistics are presented. Furthermore, so far unrevealed properties of the h-index are analysed in the context of rank-frequency and extreme-value statistics.     

Mathematical aspects of a new criterion for ranking scientific institutions based on the h-index

We develop and discuss the theoretical basis of a new criterion for ranking scientific institutions. Our novel index, which is related to the h-index, provides a metric which removes the size dependence. We discuss its mathematical properties such as merging rules of two sets of papers and analyze the relations between the underlying rank/citation-frequency law and the h-index. The proposed index should be seen as a complement to the h-index, to compare the scientific production of institutions (universities, laboratories or journals) that could be of disparate sizes.     

The h-index of h-index and of other informetric topics

In this paper we examine the applicability of the concept of h-index to topics, where a topic has index h, if there are h publications that received at least h citations and the rest of the publications on the topic received at most h citations. We discuss methodological issues related to the computation of h-index of topics (denoted h-b index by BANKS [2006]). Data collection for computing the h-b index is much more complex than computing the index for authors, research groups and/or journals, and has several limitations. We demonstrate the methods on a number of informetric topics, among them the h-index.     

Impact of bibliometric studies on the publication behaviour of authors

It has been widely discussed how individuals change the way they act and react in studies just because they are under observation. In this paper, we try to analyse how this so-called Hawthorne effect applies to researchers that are the subject of bibliometric investigations. This encompasses individual assessments as well as international performance comparisons. We test various bibliometric indicators for notable changes in the last decade from a world-wide perspective and deduce explanations for changes from the observations. We then concentrate on the behaviour of German authors in particular, to show national trends. The German publication behaviour is evaluated in regard to citation rates and collaborations in publications and size, publisher country and impact of the journals chosen for publication. We can conclude that authors adapt their publication behaviour to aim for journals that are more internationally known and have a US publisher. Also, a trend from more specialized journals to journals with a broader scope can be observed that raises the question whether the implicit penalization of specialized fields in the bibliometrics leads to undesired shifts in conducted research.     

An investigation on mathematical models of the h-index

Based on two large data samples from ISI databases, the author evaluated the Hirsch model, the Egghe-Rousseau model, and the Glänzel-Schubert model of the h-index. The results support the Glänzel-Schubert model as a better estimation of the h-index at both journal and institution levels. If h _c , h _p and h _pc stand for the Hirsch estimation, Egghe-Rousseau estimation, and Glänzel-Schubert estimation, respectively, then an inequality h _p < h ～ h _pc < h _c holds in most cases.     

Impact of country self-citations on bibliometric indicators and ranking of most productive countries

Scientometrics - The aim of the present work is to determine the share of country self-citations and to analyze its impact on total citations, average citation per paper, % cited publications and...     

Mathematical derivation of the scale-dependence of the h-index and other h-type indices

We present a mathematical derivation of the scale-dependence of the h-index. This formula can be used in two cases: one where the units are scale-dependent and one where the units are not scale-dependent. Examples are given.     

How to interpret the position of private sector institutions in bibliometric rankings of research institutions

This paper analyzes the positions of institutions from the private domain in bibliometric rankings of as many as 27,000 research institutions and highlights factors that are crucial for a proper interpretation of such positions. It was found that among the institutions with the largest output in terms of published research articles, private firms are underrepresented, whereas in the top quartile of institutions with the largest citation impact firms are overrepresented. A firm’s publication output is not a good indicator of its R&D investment: big firms in Pharmaceutics are both heavy investors in R&D and frequent publishers of scientific articles, whereas in Automobiles firms tend to invest heavily in R&D but their publication output is low. This is ascribed to the fact that the former need a validation of their results by the scientific community, while the latter do less so. Private institutions generating the largest citation impact tend to collaborate with the best public research institutions. This reflects the crucial importance of publicly funded research for the private sector.     

Exploring the limitations of the h-index and h-type indexes in measuring the research performance of authors

Scientometrics - With the introduction of an increasing number of evaluation indexes, researchers have begun to pay attention to the limitations of such indexes in research evaluation,...     

Fatal attraction: Conceptual and methodological problems in the ranking of universities by bibliometric methods

Summary A system of input, output, and efficiency indicators is sketched out, with each indicator related to basic research, applied research, and experimental development. Mainly, this scheme is inspired by empirical innovation economics (represented in Germany, e.g., by H. Grupp) and by &ldquo;advanced bibliometrics&apos; and scientometrics (profiled by van Raan and others). After considering strengths and weaknesses of some of the indicators, possible additional &ldquo;entry points&apos; for institutions of information delivery are examined, such contributing to an enrichment of existing indicators. And to a &ldquo;National&ouml;konomik des Geistes&apos;, requested from librarians in the twenties of the last century by A. von Harnack.     

Exploring the h-index at the author and journal levels using bibliometric data of productive consumer scholars and business-related journals respectively

Summary Using both author-level and journal-level data, Hirsch's h-index is shown to possess substantial heuristic value in that it yields accurate results whilst requiring minimal informational acquisition effort. As expected, the h-index of productive consumer scholars correlated strongly with their total citation counts. Furthermore, the h-indices as obtained via ISI/Thompson and GoogleScholar were highly correlated albeit the latter yielded higher values. Finally, using a database of business-relevant journals, a significant correlation was found between the journals' h-indices and their citation impact scores.     

An information fusion and decision method based on belief-discount and probability ranking of focal elements

针对基于贝叶斯推理的定位方法难于获取节点位置先验信息的问题,提出了一种应用于室内定位的Dempster-Shafer信息融合与决策方法.采用Pignistic概率反映接入点证据在焦元信度分配上的冲突并根据冲突程度对信度打折,从而实现对冲突证据的预处理.通过合成预处理后的证据可消除定位过程中出现的一票否决和Zadeh悖论现象.根据焦元各自信任区间确定的分布函数,分别计算两焦元信度在整个信任区间上降序排列的概率,并将其作为在信任区间发生重叠的焦元间进行决策的依据.算例结果表明,上述方法对冲突证据的合成更加符合证据理论的本质,且收敛速度快,决策风险低.     

Counting methods are decisive for rankings based on publication and citation studies

Summary For all rankings of countries research output based on number of publications or citations compared with population, GDP, R&D and public R&D expenses, and other national characteristics the counting method is decisive. Total counting (full credit to a country when at least one of the authors is from this country) and Fractional Counting (a country receives a fraction of full credit for a publication equal to the fraction of authors from this country) of publications give widely different results. Counting methods must be stated, rankings based on different counting methods cannot be compared, and Fractional Counting is to be preferred.     

Synthesis and characterization of antioxidants and detergent dispersant based on some polyisobutylene copolymers

Polyisobutylene succinic anhydride-urea/polyamines (PIBSA) copolymers were synthesized as potential antioxidants and detergent dispersant agents for lubricating oils samples (SAE-30). Homogeneity, thermal stability and dispersancy of the solutions were determined. Fully soluble oil compounds that are thermally stable up to 250 °C were achieved. The oxidation stability of lube oil samples in the presence of four designed PIBSA additives (varying in the number of amine groups) was determined for a time period of up to 72 hours. The dependence of the additive efficiency on its concentration was studied to achieve maximum stability. Some PIBSA additives at concentration 3.0 · 10⁴ ppm exhibit the best results. Dispersivity values were measured at predetermined oxidation times. The results proved reliable dispersion capability as the nitrogen content of the additive is increased, i.e. the increase in the basic character of the additive leads to the increase in the neutralization capability. Moreover, the designed PIBSA additives retain their efficiency after long oxidation times, confirming their role as multifunctional nitrogen containing polymeric additive. Electronic Publication     

A rationale for the relation between the citer h-index and the classical h-index of a researcher

The citer h-index of a researcher (introduced by Ajiferuke and Wolfram) was found to have a strong linear relationship with the h-index of this researcher. This finding of Franceschini, Maisano, Perotti and Proto also revealed, experimentally, that the slope of this straight line (passing through the origin) is strictly larger than one. In this paper we present a rationale for this empirical result of this author on the relation between the h-index before and after a transformation of the citation data.     

An insight into the importance of national university rankings in an international context: the case of the I-UGR rankings of Spanish universities

The great importance international rankings have achieved in the research policy arena warns against many threats consequence of the flaws and shortcomings these tools present. One of them has to do with the inability to accurately represent national university systems as their original purpose is only to rank world-class universities. Another one has to do with the lack of representativeness of universities’ disciplinary profiles as they usually provide a unique table. Although some rankings offer a great coverage and others offer league tables by fields, no international ranking does both. In order to surpass such limitation from a research policy viewpoint, this paper analyzes the possibility of using national rankings in order to complement international rankings. For this, we analyze the Spanish university system as a study case presenting the I-UGR Rankings for Spanish universities by fields and subfields. Then, we compare their results with those obtained by the Shanghai Ranking, the QS Ranking, the Leiden Ranking and the NTU Ranking, as they all have basic common grounds which allow such comparison. We conclude that it is advisable to use national rankings in order to complement international rankings, however we observe that this must be done with certain caution as they differ on the methodology employed as well as on the construction of the fields.     

The h-index and its alternatives: An application to the 100 most prolific economists

The h-index is a recent but already quite popular way of measuring research quality and quantity. However, it discounts highly-cited papers. The g-index corrects for this, but it is sensitivity to the number of never-cited papers. Besides, h- or g-index-based rankings have a large number of ties. Therefore, this paper introduces two new indices, and tests their performance for the 100 most prolific economists. A researcher has a t-number (f-number) of t (f) if t (f) is the largest number for which it holds that she has t (f) publications for which the geometric (harmonic) average number of citations is at least t (f). The new indices overcome the shortcomings of the old indices.     

基于经济损失的风险优先值排序方法研究及应用

针对传统失效模式和影响分析(FMEA)中风险优先等级(RPN)分析方法存在的离散性、重复性,以及灵敏度低、准确性差等缺陷,提出了一种基于经济损失的风险优先值排序方法——ERPN(risk priority number ranking method based on the economic losses).该方法采用定性与定量相结合的方式,首先确定某潜在失效情景的严重度,然后根据相关数据确定某初始事件发生概率以及此潜在失效情景所导致的经济损失,用两者的乘积作为ERPN值.该方法直接可观,可操作性强,具有较好的工程实用性.将其与基于反向鱼骨图的结构分解、基于情景的失效分析相结合,综合应用在自动包装生产线的送膜包覆装置的失效分析中,取得了很好的效果.     

Impact of health science research on the Spanish health system,based on bibliometric and healthcare indicators

The present study aimed to determine the possible impact of medical research on the Spanish health system. To this end, an analysis was conducted of Spanish researchers’ scientific production, measured in terms of the publications cited in MEDLINE, along with a series of economic, demographic and socio-sanitary data such as the R&D resources allocated to medical science, the actual population during the period studied mortality, morbidity and drug spending. The results showed increases in all the variables studied, identified the areas most intensely researched and defined the relationship between this information and the chief causes of mortality, morbidity and drug spending.     

The influence of random removal of sources and items on the h-index

If we have two information production processes with the same h-index, random removal of items causes one system to have a higher h-index than the other system while random removal of sources causes the opposite effect. In a Lotkaian framework we prove formulae for the h-index in case of random removal of items and in case of random removal of sources. In conclusion, we warn for the use of the h-index in case of incomplete data sets.