1,721,070 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Slip systems, lattice rotations and dislocation boundaries
No full textPlastic deformation by slip induces rotations of the crystallographic lattice and evolution of dislocation structures. Both lattice rotations and dislocation structures exhibit a dependence on the grain orientation, which reflects underlying relations to the slip pattern. Relations between the type of dislocation structure formed, in particular the crystallographic alignment of dislocation boundaries, and the slip pattern are demonstrated. These relations are applied to polycrystals deformed in tension and rolling, producing good agreement with experiment for rolling but less good agreement for tension. The grain orientations, for which the relations do not hold in tension, are also the grain orientations where the deviation between lattice rotations observed by three-dimensional X-ray diffraction (3DXRD) during tension deviate the most from those predicted with the Taylor model. The origin of these discrepancies is discussed. Finally, the implications of the relations between slip and dislocation structures for the modelling of mechanical properties are discussed
Danish Chinese Center for Nanometals
No full textThe Danish-Chinese Center for Nanometals is funded by the Danish National Research Foundation and the National Natural Science Foundation of China. The Chinese partners in the Center are Institute of Metal Research in Shenyang, Tsinghua University and Chongqing University. The Danish part of the Center is located at Risø DTU. The Center investigates metals, including light metals and steels, with internal length scales ranging from a few nanometers to a few micrometers. The structural morphologies studied are highly diverse, including structures composed of grain boundaries, twins and dislocation boundaries and spatial arrangements spanning from equiaxed to lamellar structures. The scientific focus is to understand and control the mechanisms and parameters determining the mechanical and physical properties of such metals as well as their thermal stability. An overview of the Center will be presented, including selected scientific highlights with a focus on aluminium
Microstructural evolution at multiple scales during plastic deformation
Get PDFDuring plastic deformation metals develop microstructures which may be analysed on several scales, e.g. bulk textures, the scale of individual grains, intragranular phenomena in the form of orientation spreads as well as dislocation patterning by formation of dislocation boundaries in metals of medium to high stacking fault energy. Experimental data and associated data analysis at the grain scale and below will be presented to illustrate our current level of understanding. The basis for the analysis is the crystallographic orientation of the grain as well as the slip systems that are activated. More specifically the origin of both inter- and intragranular orientation spread is analysed for a specific example from tensile deformed interstitial-free steel [Oddershede et al. 2015]. A universal framework for the patterns consisting of dislocation boundaries is presented for both fcc and bcc materials in several deformation modes, demonstrating a clear grain orientation dependence [Huang & Winther, 2007]. This dependence has its origin in a dependence on the slip systems [Winther & Huang, 2007]. This further implies that the dislocations in the boundaries come from the active slip systems, which is backed up by experimental data [McCabe et al. 2004; Wei et al., 2011; Hong, Huang, & Winther, 2013]. The current state of understanding as well as the major challenges are discusse
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