1,720,991 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
Recommendations of RILEM TC 252-CMB on the Effect of Short Term Aging Temperature on Long Term Properties of Asphalt Binder
No full textThe Rilem Technical Committee on Chemo Mechanical Characterization of Bituminous Materials has investigated the effect of short term aging tempera-ture on long term properties of asphalt binder, chemically, physically and mi-crostructurally. The increased use of warm mix asphalt (WMA) technologies warrants such investigations in order to validate laboratory aging procedures. To this end, penetration, softening point, Fourier Transform Infrared Spec-troscopy, dynamic shear rheology (DSR) and electron microscopy (ESEM) were used. The experimental results on binders and warm (WMA) and hot (HMA) mixtures from nine participating laboratories indicate that the binder source, as well as method of evaluation, result in different rankings and be-haviors among the four binders used. The TC recommends the development of appropriate RTFOT aging temperatures for the simulation of binder aging in WMA
Organic Compounds Evaluation from Fumes Generated in Laboratory by Bio-recycled Asphalt Mixtures
No full textUsing bio-binder and bio-additives as recycling agents for asphalt
mixtures with high-content of reclaimed asphalt (RA) is proving to be feasible.
It is still not clear whether this combination might provide new hazardous
emissions from airborne binder fumes. The health hazard related to airborne
bitumen fume generation is primarily relevant for paving crews while there is
little opportunity for exposure related to asphalt plant workers. In this study,
measurements of gaseous organic compounds from airborne binder fumes of
selected bio-asphalt mixtures have been measured during the laboratory mixing
process, by using a thermo-mixer equipped with a chimney at University
Gustave Eiffel. Parameters studied are the binder nature, mix formula and
mixing temperatures. Results show that generally combining bio-based
materials and RA is as safe as using conventional bitumen and RA, however
thanks to this approach it was possible to identify a strong link between
bituminous material composition and their emission potentia
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
Effects of rejuvenator on reclaimed asphalt binder: An exploratory study of the RILEM TC 264-RAP task group 3
No full textThis paper presents the preliminary experimental activity conducted to develop the round robin test (RRT) plan on the use of rejuvenators for the Task Group (TG) 3 on Asphalt Binder for Recycled Asphalt Mixtures as part of the RILEM TC 264-RAP. For this purpose, a reference Reclaimed Asphalt (RA) binder was extracted from a single RA source. This material was then fully characterised with conventional experimental methods and with Fourier Transform Infrared Spectroscopy (FTIR) for evaluating the chemical structure. The RA binder was found to be very hard compared to target binder of PEN50/70 grade and the use of virgin binder cannot restore its properties. In this condition, a rejuvenator dosage of 9% per weight of RA binder is foreseen as optimum value to restore the binder properties close to target PEN50/70 grade for the final binder-rejuvenator blend over a RA content ranging from 60% and 100%
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
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