1,724,320 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
Parametrized modified gravity constraints after Planck
No full textWe constrain f(R) and chameleon-type modified gravity in the framework of the Berstchinger-Zukin parametrization using the recently released Planck data, including both the cosmic mircowave background radiation (CMB) temperature power spectrum and the lensing potential power spectrum. Some other external data sets are included, such as baryon acoustic oscillation (BAO) measurements from the 6dFGS, SDSS DR7 and BOSS DR9 surveys; Hubble Space Telescope (HST) H0 measurements, and supernovae from the Union2.1 compilation. We also use WMAP9 data for a consistency check and comparison. For f(R) gravity, WMAP9 results can only give a quite loose constraint on the modified gravity parameter B0, which is related to the present value of the Compton wavelength of the extra scalar degree of freedom, B0<3.37 at 95% C.L. We demonstrate that this constraint mainly comes from the late integrated Sachs-Wolfe effect. With only Planck CMB temperature power-spectrum data, we can improve the WMAP9 result by a factor 3.7 (B0<0.91 at 95% C.L.). If the Planck lensing potential power-spectrum data are also taken into account, the constraint can be further strengthened by a factor 5.1 (B0<0.18 at 95% C.L.). This major improvement mainly comes from the small-scale lensing signal. Furthermore, BAO, HST and supernovae data could slightly improve the B0 bound (B0<0.12 at 95% C.L.). For the chameleon-type model, we find that the data set that we used cannot constrain the Compton wavelength B0 or the potential index s of the chameleon field, but it can give a tight constraint on the parameter β1=1.043-0.104+0.163 at 95% C.L. (β1=1 in general relativity), which accounts for the nonminimal coupling between the chameleon field and the matter component. In addition, we find that both modified gravity models we consider favor a relatively higher Hubble parameter than the concordance ΛCDM model in general relativity
Future CMB integrated-Sachs-Wolfe-lensing bispectrum constraints on modified gravity in the parametrized post-Friedmann formalism
No full textWe forecast the constraints on both the Hu-Sawicki model and the Bertschinger-Zukin model of f(R) modified gravity within the parametrized post-Friedmann formalism for the Planck satellite experiment by performing the joint analysis of the integrated-Sachs-Wolfe-lensing bispectrum and cosmic microwave background power spectrum. We find that, even considering the temperature-temperature mode of cosmic microwave background power spectrum only, Planck data are expected to reduce the error bars on the modified gravity parameter B0 (related to the present value of the Compton wavelength of the extra scalar degree of freedom) at least one order magnitude compared with Wilkinson microwave anisotropy probe. The spectrum-bispectrum joint analysis can further improve the results by a factor ranging from 1.14 to 5.32 depending on the specific modified gravity model. One of our main results is that the cross correlation between the integrated-Sachs-Wolfe-lensing bispectrum and the power spectrum can be safely neglected when performing the joint analysis. For simplicity, we investigate only the likelihood of one parameter (B0) and fix all other cosmological parameters to their best-fit values in Wilkinson microwave anisotropy probe 7-yr results
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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