1,721,363 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
Comparison of the materialisation of the tide gauges in use in Italy as support for the correct implementation of the national seagrass mapping project
No full textThe definition of a reference system is the first moment of a survey operation but is in some ways perhaps the most critical because on its correct definition depends on the reliability and significance of all subsequent operations. From the simplest local survey to the most complex surveys of large extensions that often require the joint use of different technologies, it is in fact of paramount importance to define a planimetric or planoaltimetric datum that allows all subsequent survey operations to be correctly referenced and make the various observations consistent. In this paper we illustrate the first considerations that have been made for the correct framing of the high-resolution bathymetric surveys of a future national project to survey all the coastal areas and the relative seafloor for the entire Italian coastline; peninsula, major islands and minor islands. The different geomatic techniques that will necessarily be used require the study and definition of certain methodologies to refer all observations to a common reference to ensure compatibility and comparability. Particularly critical is the altimetry aspect for which it is necessary to consider the shift between ellipsoid heights, orthometric heights and heights referring to the local mean sea level. It is precisely the last transition that is perhaps the most critical because it requires the local study of the framing and materialisation of the tide gauges. The main tide gauges of the national system have been studied here, confirming the complexity of this certain definition and suggesting possible developments in the definition of conversion methodologies
Indagini in acqua
No full textSi riportano le strutture archeologiche rinvenute nel fiume Tevere con le prospezioni multibea
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
First considerations on post processing kinematic GNSS data during a geophysical oceanographic cruise
Full text linkDifferential GNSS positioning on vessels is of considerable interest in various fields of application as navigation aids, precision positioning for geophysical surveys or sampling purposes especially when high resolution bathymetric surveys are conducted. However ship positioning must be considered a kinematic survey with all the associated problems. The possibility of using high-precision differential GNSS receivers in navigation is of increasing interest, also due to the very recent availability of low-cost differential receivers that may soon replace classic navigation ones based on the less accurate point positioning technique. The availability of greater plano-altimetric accuracy, however, requires an increasingly better understanding of planimetric and altimetric reference systems. In particular, the results allow preliminary considerations on the congruence between terrestrial reference systems (which the GNSS survey can easily refer to) and marine reference systems (connected to National Tidegauge Network). In spite of the fluctuations due to the physiological continuous variation of the ship's attitude, GNSS plot faithfully followed the trend of the tidal variations and highlighted the shifts between GNSS plot and the tide gauges due to the different materialization of the relative reference systems
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