1,720,964 research outputs found
Anatomy of falling stage to early transgressive fluvial-deltaic deposits: outcrop and borehole data from the lacustrine late Pliocene of the Upper Valdarno Basin (Italy)
No full textLandsat TM and Quickbird images for geological mapping in the syn-rift Lower Dogali Formation (Red Sea coast, NE Eritrea)
No full textSyn-rift Neogene deposits, composed of a 650 m
thick volcano-sedimentary succession, crop out at
the foot of the escarpment close to the village of
Dogali, near Massawa (NE Eritrea). These
deposits are related to the first stage of the Red Sea
spreading. This work aims at mapping in detail this
succession using remote sensing optical images
integrated with ancillary data and ground truth
information in a Geographic Information System.
Optical images are usually effective in lithological
discrimination in arid environment and fill the
requirements of low-cost, rapid and accurate
regional mapping. Photo-interpretation of Landsat
Thematic Mapper image was carried out in a test
area of 500 km2 and Quickbird satellite images
were used to detail a subset of 50 km2. The satellite
images have been processed through radiometric
enhancement, principal components analysis and
band ratios. Ancillary data and evidences from
field surveys supported the photo-interpretation.
Rock samples, photos and observations collected
during previous test campaigns provided interpretation
keys of the satellite images. A preliminary
scheme of the lithological units has been drawn
from the Landsat image. The Proterozoic metamorphic
complex of the basement and the sedimentary
facies of Lower Dogali Formation were mapped at
scale 1:80,000. Evidences of laterites and basement
weathering were also detected. A detailed
analysis of sedimentary facies of the Lower Dogali
Formation was then carried out using the
Quickbird images at scale 1:10,000. The results of
the photointerpretation of remotely sensed data
confirm that the deposition of the Lower Dogali
Formation is linked to the first stage of the Red Sea
spreading and main considerations on the mechanisms
and the evolution of different stages have
been underlined. Although the next field campaign
is going to endorse the remotely sensed data, these
preliminary results give evidence of the contribution
of satellite images to the knowledge of the geological
setting of a poorly mapped area in arid
environment
The Plio-Pleistocene, fluvio-lacustrine Upper Valdarno Basin (central Italy): stratigraphy and basin fill evolution
No full text
Plan-form evolution of ancient meandering rivers reconstructed from longitudinal outcrop sections
No full text
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
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
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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