The Google Scholar h-index: useful but burdensome metric

Scientometrics - A recent paper in Scientometrics highlighted how the h-index of an academic can be represented differently by different platforms, for example by Web of Science, Scopus, Google...     

Dispersion measures for h-index: a study of the Brazilian researchers in the field of mathematics

Although the h-index is considered a significant indicator to evaluate the researchers' performance, as it simultaneously measures aspects related to their scientific productivity and citation impact, several studies have pointed out its deficiencies and limitations. In this context, this study aims to evaluate the contribution of dci and dco indicators, two Hirsch-type indices, to measure the reasonableness of the h-index as a representation of the researcher’s scientific performance. The universe of analysis consisted of 116 Brazilian mathematicians holding CNPq grants. For each researcher, the number of articles, the number of citations per article and the year of publication were collected in the Scopus database. Then, for each researcher, the h-index and dci and dco indices were calculated. The dci and dco indicators allowed selective and productive researchers to be to distinguished more accurately. In addition, they contributed to estimate the possibility of the researcher to increase his/her h-index. The study concludes that the dci and dco indices were able to reliably measure the distribution dispersion of the researchers' citation impact together with their h-index. Consequently, they managed to estimate the representativeness of h-index as an indicator of the researchers' scientific performance in the field of mathematics in Brazil.

     

Scientific Quality Index: a composite size-independent metric compared with h-index for 480 medical researchers

Scientometrics - The goal of this study was to measure the scientific output of 480 authors—leaders in 12 selected branches of medicine, using the Hirsch index (the h-index) and a newly...     

The HF-rating as a universal complement to the h-index

Scientometrics - Interdisciplinary comparison has been a constant objective of bibliometrics. The well-known h-index and its alternatives have not achieved this objective. Based on the gh-rating or...     

Nondestructive evaluation of timber: the new Brazilian code for the design of timber structures

The grading of structural timber members allows for their greater efficiency and quality. This grading can be done by means of nondestructive methods that improve the evaluation process. Timber grading makes it possible to augment the k _mod,3 coefficient, resulting in greater structural reliability. The purpose of this work was to calibrate the modification coefficient (k _mod,3) of the Brazilian NBR 7190:2007 code for the Design of Timber Structures. The modification coefficients are numbers that govern the estimation of a property of a material as a function of phenomena that may occur permanently or during a certain period of the service life of the building, being that the coefficient k _mod,3 leads in consideration if the wood is of first or second-class quality. The experimental procedure involved a study of structural members of Eucalyptus grandis and Pinus sp., which were graded by ultrasound and transverse vibration techniques to determine the dynamic modulus of elasticity (E_d). The members were visually graded and static bending tests (MOE) were conducted concomitantly. The results indicated that the transverse vibration technique yielded higher modification coefficient (k _mod,3) values than the ultrasound technique, since it grades the material at values closer to those obtained in static bending.     

Comprehensive evaluation of h-index and its extensions in the domain of mathematics

Scientometrics - Until the late 90’s, conventional bibliometric indices such as, publication count, citation count, and number of co-authors have extensively been employed by the scientific...     

Correction to: The HF-rating as a universal complement to the h-index

Scientometrics - In the original publication of the article, the author name was published incorrect. The correct name is given with this Correction.     

Cystic resolution: a performance metric for ultrasound imaging systems

This paper describes a metric that can be used to characterize the resolution of arbitrary broadband coherent imaging systems. The metric is particularly suited to medical ultrasound because it characterizes scanner performance using the contrast obtained by imaging anechoic cysts of various sizes that are embedded in a speckle-generating background, accounting for the effect of electronic noise. We present the theoretical derivation of the metric and provide simulation examples that demonstrate its utility. We use the metric to compare a low-cost, handheld, C-scan system under development in our laboratory to conventional ultrasound scanners. We also present the results of simulations that were designed to evaluate and optimize various parameters in our system, including the f/# and apodization windows. We investigate the impact of electronic noise on our system and quantify the tradeoffs associated with quantization in the analog to digital converter. Results indicate that an f/1 receive aperture combined with 10-bit precision and a signal-to-noise ratio (SNR) of 0 dB per channel would result in adequate image quality.     

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.     

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.     

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.     

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,...     

Correlations between bibliometrics and peer evaluation for all disciplines: the evaluation of Brazilian scientists

This paper correlates the peer evaluations performed in late 2009 by the disciplinary committees of CNPq (a Brazilian funding agency) with some standard bibliometric measures for 55 scientific areas. We compared the decisions to increase, maintain or decrease a scientist’s research scholarship funded by CNPq. We analyzed these decisions for 2,663 Brazilian scientists and computed their correlations (Spearman rho) with 21 different measures, among them: total production, production in the last 5 years, production indexed in Web of Science and Scopus, total citations received (according to WOS, Scopus, and Google Scholar), h-index and m-quotient (according to the three citation services). The highest correlations for each area range from 0.95 to 0.29, although there are areas with no significantly positive correlation with any of the metrics.     

Evaluation of Moroccan research using a bibliometric-based approach: investigation of the validity of the h-index

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.     

Experimental performance of a direct evaporative cooler operating during summer in a Brazilian city

This paper presents the basic principles of the evaporative cooling process for human thermal comfort, the principles of operation for the direct evaporative cooling system and the mathematical development of the equations of thermal exchanges, allowing the determination of the effectiveness of saturation. It also presents the results of experimental tests in a direct evaporative cooler that take place in the Air Conditioning Laboratory at the University of Taubaté Mechanical Engineering Department, and the experimental results are used to determinate the convective heat transfer co-efficient and to compare with the mathematical model.     

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.     

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.     

Construction and evaluation of the first Brazilian atomic clock

For the past two years we have been implementing a program for the establishment of scientific time and frequency metrology in Brazil. The main objective of this program is to construct an atomic fountain and use it as a primary standard. As a first step toward this goal, we have constructed a (133)Cs beam optically pumped conventional clock. In this paper we describe the system and the results of its evaluation. The possible limitations of our short-term stability are discussed.