Search Results
Abstract
This paper presents the results of an evaluation of the national research system in Morocco. The exercise focuses on the period 1997–2006 and includes a comparison with South Africa, Egypt, Nigeria, Tunisia, Algeria, Portugal and Greece. Ratings of highly ranked researchers are developed on the basis of their number of publications, number of citations and also their ‘h-index’ (or Hirsch index). Finally, we examine the empirical model set by Glänzel that related the h-index to the number of publications and the mean citation rate per paper for these ‘upper-class’ researchers. The use of this model confirms that the h-index is likely to reflect the importance and the quality of the scientific output of a given researcher.
Abstract
From a list of papers of an author, ranked in decreasing order of the number of citations to these papers one can calculate this author’s Hirsch index (or h-index). If this is done for a group of authors (e.g. from the same institute) then we can again list these authors in decreasing order of their h-indices and from this, one can calculate the h-index of (part of) this institute. One can go even further by listing institutes in a country in decreasing order of their h-indices and calculate again the h-index as described above. Such h-indices are called by Schubert [2007] “successive” h-indices. In this paper we present a model for such successive h-indices based on our existing theory on the distribution of the h-index in Lotkaian informetrics. We show that, each step, involves the multiplication of the exponent of the previous h-index by 1/α where α > 1 is a Lotka exponent. We explain why, in general, successive h-indices are decreasing. We also introduce a global h-index for which tables of individuals (authors, institutes,...) are merged. We calculate successive and global h-indices for the (still active) D. De Solla Price awardees.
Abstract
For determining the eminence of scientific journals, a new indicator stressing the importance of papers in the “elite set” (i.e., highly cited papers) is suggested. The number of papers in the elite set (P πv) is calculated with the equation: (10 log P) − 10, where P is the total number of papers in the set. The one-hundredth of citations (C) obtained by P πv papers is regarded as the πv-index which is field and time dependent. The πv-index is closely correlated with the citedness (C/P) of P πv papers, and it is also correlated with the Hirsch-index. Three types of Hirsch-sets are distinguished, depending on the relation of the number of citations received by the Hirsch-paper (ranked as h) and the paper next in rank (h + 1) by citation. The h-index of an Anomalous Hirsch-set (AH) may be increased by a single citation to a paper outside the Hirsch-core. (A set of papers may be regarded as AH, where the number of citations to the Hirsch-paper is higher than the h-index and the next paper in rank shows as many citations as the value of the h-index.)
Abstract
In academia, the term “inbreeding” refers to a situation wherein PhDs are employed in the very same institution that trained them during their doctoral studies. Academic inbreeding has a negative perception on the account that it damages both scientific effectiveness and productivity. In this article, the effect of inbreeding on scientific effectiveness is investigated through a case study. This problem is addressed by utilizing Hirsch index as a reliable metric of an academic's scientific productivity. Utilizing the dataset, constructed with academic performance indicators of individuals from the Mechanical and Aeronautical Engineering Departments, of the Turkish Technical Universities, we demonstrate that academic inbreeding has a negative impact on apparent scientific effectiveness through a negative binomial model. This model appears to be the most suitable one for the dataset which is a type of count data. We report chi-square statistics and likelihood ratio test for the parameter alpha. According to the chi-square statistics the model is significant as a whole. The incidence rate ratio for the variable “inbreeding” is estimated to be 0.11 and this ratio tells that, holding all the other factors constant, for the inbred faculty, the h-index is about 89% lower when compared to the non-inbred faculty. Furthermore, there exists negative and statistically significant correlation with an individual's productivity and the percentage of inbred faculty members at the very same department. Excessive practice of inbreeding adversely affects the overall productivity. Decision makers are urged to limit this practice to a minimum in order to foster a vibrant research environment. Furthermore, it is also found that scientific productivity of an individual decreases towards the end of his scientific career.
Hirsch-index of this ranked set is called the single publication H -index of this single publication. This single publication H -index is, hence, a measure of indirect impact of the single publication since it uses citations to the papers that
leathers, parchments and woods and, last but not least, adsorption and catalysis. He has more than 150 publications which are highly cited (Hirsch index = 17). Prof. Budrugeac is the president of the Commission of Thermal Analysis and Calorimetry of the
., Berhidi, A., Vasas, L., et al.: Hirsch-index for countries based on Essential Science Indicators data. Scientometrics, 2007, 73 (1), 91–117. 11 Iglesias, J. E
Introduction The Hirsch-index (or h-index, Hirsch 2005 ) is now a well-established indicator of impact of an object (journal, author, topic, institute, etc.) (Braun et al. 2005 , 2006 ; Banks 2006 ; van Raan 2006 ). Yet
Introduction The Hirsch-index or h -index is defined for a decreasing sequence of positive numbers. In the original article Hirsch 2005 one has a decreasing sequence of citations to articles (e.g. of a researcher). As such
stochastic model . Journal of Informetrics 1 1 16 – 25 10.1016/j.joi.2006.07.001 . Burrell , QL 2007 Hirsch index or Hirsch rate? Some thoughts arising from Liang's data
