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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
AFATA (Active FAult Tectonic Analysis): a semi-automatic tool on ArcGIS.for estimating fault offset on superficial ruptures
No full textThe automation of data acquisition and calculation is advancing in many sectors. At the same time, the use of software and the difficulty, in certain cases, in programming languages could lead to various problems.
In relation to the automation of fault offset estimation, many authors have given their contribution (Stewart et al., 2018; Wolfe et al., 2020) combining steps in GIS environment with external programming languages.
AFATA is a new toolbox proposal for ArcGIS® based on Model Builder and on ArcPy language for the evaluation of the three components of rupture offset (vertical, horizontal and along plane offsets) of a normal fault. This tool, that only needs the use of GIS environment, is intuitive and does not require many steps from the user. The semi-automatic process allows the operator to modify and improve the shapefiles on which the analysis is carried out.
The AFATA main inputs are (i) line shapefiles, drawn by the operator, defining the two limits of the fault offset, and (ii) a slope raster obtained through a Digital Elevation Model (DEM) with a resolution comparable with the fault geometry. The result is a line shapefile containing the sampling transects whose frequency is chosen by the user along the fault plane. The measurements (maximum, minimum and average) of the three offset components and the value of the slope angle for each transect are shown in the attribute table. The application and validation of the proposed toolbox are located in the Central Apennines of Italy on the surface ruptures related to the 2016 earthquakes. The study area was surveyed with a digital geological field survey and with low-altitude aerial photos, using an Unmanned Aerial Vehicle (UAV). A 3D Virtual Outcrops
Model (VOM) was generated by the Structure from Motion – MultiView Stereo (SfM-MVS) photogrammetry (Westoby et al., 2012; Tavani et al., 2016); from this, a 0.009 m resolution ortophoto and a 0.02 m resolution DEM were derived for spatial analysis in ArcGIS 10.8.1.
The AFATA application may contribute to obtain a higher number of measurements by regularly scanning
the three components of the slip fault, in particular on ruptures difficult to access. The extent of the error for this tool primarily depends on the accuracy with which the user draws the limits; the estimated error obtained on the study area is about 10% of the total slip
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
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