1,720,994 research outputs found
Analisi della ripetibilità del metodo GPS differenziale
No full textEsperimenti di GPS cinematico su autoveicoli , su imbarcazioni a motore e veicoli ferroviari, cabine di funivie. Risultati degli esperimenti ai fini della determinazione della ripetibilità e per determinare le traiettorie
Comparison of EGNOS and Global Maps Vertical TEC in the Southern part of ECAC Region at Range Delay and Position Domain
No full textThis research work provides an overview of the comparison of EGNOS, Global Maps
and experimental data position errors over the Southern part of the ECAC region, on the basis
of TEC values. It is well known that ionospheric conditions represent the main factor that influences
GNSS positioning accuracy at the frequency operation. The satellite signals experience a
delay when passing through the ionosphere. This delay depends on several factors such as
geographical location of the receiver, solar and geomagnetic activity, season and hours of the
day. It results in range errors that can vary from few meters to tens of meters. To overcome
this problem, augmentation system (SBAS) based on geostationary satellites support have
been developed. These systems use a grid-based model to determine the delay introduced by
the ionosphere. Since the delay magnitude depends linearly on the total number of free
electrons in the ionosphere, the delay model corresponds to values of Total Electron Content
(TEC). Performances of such systems are challenged in areas of large ionospheric variability
like those found at low latitude or under space weather events, such as geomagnetic storms.
The European augmentation system is EGNOS. The objective of the present study is to
evaluate on a quantitative level EGNOS performance on both delay (TEC) and positioning
domains by adequate comparisons with independent data and the use of well provided tools
like gLAB
Estimating crustal deformations by GNSS time series data analysis
No full textCrustal deformation analysis in seismogenic areas is one of the most important applications of GNSS. In the last twenty years, the GNSS technology has opened new perspectives in this field allowing the estimation of the crustal deformation at different scales both in time and in space. Tectonic deformations can be reliably estimated either at regional and fault scale. This allows the analysis of the different phases of the seismic cycle. Particularly, co-seismic and post-seismic deformations can be properly evaluated. Also, recent studies aim at studying the inter-seismic phase giving important insights in the dynamic of the crust in seismic prone areas. These studies are commonly based on the analysis of time series from GNSS permanent stations. In this paper, a method for filtering these data is presented and a case study based on the FReDNet data is illustrated
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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