1,721,030 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
Molecular changes in organic matter of a compost-amended soil.
No full textThe molecular changes of organic matter in a cultivated soil after
compost amendments was followed by off-line-pyrolysis-TMAH GC-MS.
Thermochemolysis of soil and compost provided a detailed molecular
characterization of soil organic matter (SOM) by releasing a large
amount of different molecules mainly derived from plant biopolymers
such as lignin, waxes and bio-polyesters. No significant differences
were found before and after 1 year of cultivation in the pyrolytic
products released by control soil, which were mainly fatty acids,
oxidized forms of lignins, and minor amounts of microbial bio-products
and biopolyesters derivatives. Conversely, significant qualitative and
quantitative variations were found in the molecular characteristics of
SOM between control and compost-amended soils after 1 year of
cultivation. Increasing amounts and diversified components of fatty
acids, n-alkanes and various biopolyesters derivatives such as
hydroxy-alkanoic and alkandioic acids were found in the
compost-amended soil. These results indicate that a significant amount
of exogenous compost-derived organic molecules were incorporated into
SOM after 1 year of cultivation. The organic structural indexes
derived from these results indicated direct inputs of undecomposed
lignin residues and hydrocarbon waxes from compost material. When
compared with the control soil, small but significant amounts of plant
biomarkers, such as cyclic di- and triterpenes derivatives, were found
only in the compost-amended soil. These findings suggest that the
molecular changes of SOM brought about by amendment with biomass
residues can be followed by using thermochemolysis of bulk soil samples
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
Stabilization of Co-ferrierite activity by Ag and Mn in lean CH4-SCR of NOx in the presence of water
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