1,721,049 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Deuterium hyperfine splittings in the rotational spectrum of NH2D as revealed by Lamb-dip spectroscopy
Full text linkIn the context of radio-astronomical observations, laboratory experiments constitute a cornerstone in the interpretation of rich line surveys due to the concomitant presence of numerous emitting molecules. Here, we report the investigation of three different rotational transitions of mono-deuterated ammonia (NH2D), a species of astrophysical interest, for which the contribution of the deuterium nuclear spin to the rotational spectrum has been resolved for the first time in the millimeter- and submillimeter-wave domain. The effect of hyperfine interactions on the rotational spectrum has been unveiled by a combined theoretical and experimental approach. Quantum-chemical calculations based on coupled-cluster theory have been employed to evaluate the hyperfine parameters of nitrogen, hydrogen, and deuterium in NH2D. Subsequently, the Lamb-dip technique has been used to investigate the rotational spectrum of NH2D at high-resolution. In detail, three low-J transitions have been recorded at 86, 110, and 333 GHz with a frequency-modulation millimeter-/submillimeter-wave spectrometer. From the line profile analysis of the recorded spectra, the main terms responsible for the rotational hyperfine structure have been determined with good accuracy. Our work allows a comprehensive analysis of the rotational features of NH2D in radioastronomical spectra and a more accurate evaluation of its column density, especially in non-turbulent regions showing narrow linewidths
Millimeter-Wave and Diode Laser Spectroscopy of I 13CN: Analysis of the v3 Band System
No full textThe v3, fundamental band (C-N stretch) and four associated hot bands of I 13CN have been recorded in the 2130 cm-1 region using a diode laser spectrometer. The analysis of the five infrared bands has been supported by the measurements of new millimeter-wave rotational lines for the 0000, 01 10, 1000, 0200, and 0220 states. Accurate values of the band origins and of the lower and upper state rotational constants have been determined. © 1997 Academic Press
Study of vibrational interactions in DCO+ by millimeter-wave spectroscopy and determination of the equilibrium structure of the formyl ion
No full textThe rotational transition measurements of DCO+ in bending-excited states were extended to satellites with higher values of the vibrational angular momentum quantum number, l. A detailed scheme of the energy levels within the l manifolds was derived. The equilibrium rotational constants for all the isotopomers of the formyl ion were derived by means of a proper combination of the perturbed effective rotational constants to compensate for the Coriolis contributions. In this way, an accurate equilibrium structure was obtained
The anharmonic force field of (cis)-1-chloro-2-fluoroethylene
No full textA comprehensive anharmonic vibrational analysis of cis-1-chloro-2-fluoroethylene and its isotopomers has been performed on the basis of a complete ab initio quartic force field constructed by means of second-order Moller-Plesset perturbation theory (MP2) and the coupled-cluster singles and doubles approach, augmented for structural optimization and harmonic force field by a contribution of connected triple excitations (CCSD(T)). The theoretical force field was scaled by global least-squares fitting to all spectroscopic data and parameters experimentally determined for this molecule. This final force field, employing standard perturbation theory, yields a complete set of spectroscopic molecular constants providing a critical assessment of experimental rotational and centrifugal distortion constants, fundamentals, overtones, and combination bands determined over many years. Effects of Fermi and Darling-Dennison resonances were included by matrix diagonalization
- …
