1,721,173 research outputs found

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Full text link
    The 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

    CHARACTERIZATION OF THE SUBSURFACE THROUGH JOINT HYDROGEOLOGICAL AND GEOPHYSICAL INVERSION

    Full text link
    Characterization of the subsurface heterogeneity, monitoring groundwater dynamics, modelling flow and transport in the subsoil are of paramount importance for protection of groundwater quality, design of remediation plans, control of restoration activities. One of the key physical parameters that control groundwater flow and solute transport is hydraulic conductivity. Both hydraulic conductivity and electrical resistivity depend on porosity, water content and textural properties. Moreover, the difficulties of directly and effectively measure hydraulic conductivity makes the possibility of predicting it from geophysical measurements very attractive. Hydrogeophysics provides useful complementary techniques, both for hydrostratigraphic and hydrogeological characterization and for monitoring. It provides a minimally invasive approach to obtaining spatially-continuous data-sets, at a relatively high temporal and spatial sampling density. The general-purpose objective of this work is the development of a modelling tool for the subsurface characterization, in order to improve studies on groundwater flow and contaminant transport, with the specific goal of obtaining a spatial 3D parameter distribution of hydraulic conductivity and electrical resistivity. Such a tool profits from DC geoelectrical and hydraulic collected data, which are used in a joint geophysical and hydrological data inversion, with an approach similar to the Ensemble Kalman Filter

    Appropriate Similarity Measures for Author Cocitation Analysis

    Full text link
    We 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

    Assessment of the role of facies heterogeneity at the fine scale by numerical transport experiments and connectivity indicators

    No full text
    The heterogeneity of facies at the scale of individual lithological levels controls, at a macroscopic scale, water flow and contaminant transport in porous sediments. In particular the presence of organized features such as permeable connected levels, has a significant effect on travel times and dispersion. Here, the effects of facies heterogeneity on flow and transport are studied for three blocks, whose volume is of the order of a cubic meter, dug from alluvial sediments from the Ticino valley (Italy). Using the results of numerical tracer experiments on these domains, the longitudinal dispersion coefficient is computed with an Eulerian approach based on the fit of the breakthrough curves with the analytical solution of the convective-dispersive transport equation. Moreover, the dispersion tensor is computed with a Lagrangian approach from the second order moments of particle distributions. Three types of connectivity indicators are tested: (1) connectivity function; (2) flow, transport and statistical connectivity; (3) original (intrinsic, normal and total) indicators of facies connectivity. The connectivity function provides the most complete information. Some of the transport and statistical connectivity indicators are correlated with dispersivity. The simultaneous analysis of the three indicators of facies connectivity emphasizes the fundamental geometrical features that control transport

    Dispelling the Myths Behind First-author Citation Counts

    Full text link
    We 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
    corecore