1,720,961 research outputs found
Downscaling of land surface temperature using airborne high-resolution data: A case study on Aprilia, Italy
No full textA regression-based downscaling of land surface temperature was developed over the heterogeneous urban area of Aprilia, Central Italy, using high resolution (HR) airborne data. Airborne sensors provided thermal and visible– near infrared (VNIR) measurements at 2-m pixel size. Coarse resolution images at 40, 30, and 20 m, upscaled by aggregation from the native airborne data, were sharpened to the finer resolution of 2 m. The main core of the downscaling method is the use of the spectral mixture analysis (SMA) to derive fractional pixel composition as predictors of the regression scheme. The HR VNIR data allow choosing detailed land cover types in the application of SMA, such as bright/dark roofs, and the benefit of this detailed selection is proved. The estimation error of the custom technique improves of about 10%–15% with respect to a classical regression downscaling
Rilievo di un complesso rurale nel territorio di Castiglione del Lago ed ipotesi di riqualificazione
No full textRilievo di un complesso rurale in stato di abbandono nel territorio di Castiglione del Lago (PG) con tecniche di rilievo diretto e strumental
Multi-constellation Network RTK for Automatic Guidance in Precision Agriculture
No full textGNSS navigation methods have acquired an increasing role in precision agriculture, especially for machine control and guidance, allowing to obtain high accuracy position data thanks to the RTK/NRTK technique. The aim of this work is to test the correct functioning of automatic driving systems with differential correction obtained from a regional GNSS network (GPSUmbria), evaluating the advantages of multi-constellation corrections with respect to the GPS + GLONASS configuration, more usual for agricultural applications. For testing purposes an independent geodetic receiver was installed on NRTK controlled vehicles performing a contemporary data acquisition. The
experimental campaign was carried out during different agricultural processes in test areas in Umbria (central Italy) with variable environmental conditions. The results obtained with the geodetic receiver were used as a reference solution to validate the measurements performed by the systems on board the vehicles, and comparisons were made between the accuracies obtained with GPS-GLONASS only versus a full multi-constellation navigation,
demonstrating the advantages obtainable with the latter
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
THE ETRUSCAN CITY GATES OF PERUGIA: GEOMATIC TECHNIQUES FOR THE DOCUMENTATION AND STUDY OF AN URBAN HISTORY HERITAGE
No full textThe Engineering Department of the University of Perugia and the Architecture Department of the University of Florence have started a research project on the ancient city gates of Perugia, belonging to the Etruscan city, dating between the third and second centuries B.C., and to the subsequent city wall completed in the twelfth century. In this paper, focus is placed on three Etruscan gates - Porta Eburnea (also called Porta della Mandorla), Porta Cornea and Porta Trasimena – which have in common profound Middle Age transformations and further significant context changes following the loss of function as defensive walls. Due to the decommissioning of this urban infrastructure, the gates have assumed a marginal role; nowadays they are almost completely absorbed by residential buildings, almost losing the memory of their origins and of the important Etruscan remains that are still preserved in the gates. Geomatic surveys on the three Etruscan gates were carried out by the Geomatics Laboratory of Perugia University in the frame of a research project financed by the Cassa di Risparmio di Perugia Foundation. The survey was carried out by means of a coordinated use of more Geomatic techniques: GNSS, Total Station, Terrestrial LIDAR and Digital Photogrammetry. From LIDAR and photogrammetry were derived dense point clouds, beside CAD plans, sections and elevations. The information acquired with these detailed surveys provide a completely new and accurate documentary evidence of the gates’ consistency, allowing to identify the actions and interventions that have changed their structure over time
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
Urban Geology for the Enhancement of the Hypogean Geosites: the Perugia Underground (Central Italy)
No full textUrban geology analyses natural risks and promotes geoheritage in urban areas. In the cities, characterized by a high cultural value,the hypogean artificial cavities, often present in the downtown, offer a unique opportunity to show the geological substratum.Moreover, these places could be a point of interest in urban trekking with the abiotic component of the landscape as a topic(geotourism). To investigate these areas, rigorous bibliographic research and a geomorphological assessment are the first steps,but, besides, non-invasive methods are new techniques increasingly in demand. In this paper, we present a multidisciplinarystudy on the Etruscan Well (third century B.C.), one of the most important Etruscan artefacts in Perugia (Umbria region, CentralItaly). The characteristics of the sedimentary deposits outcropping along the perimeter walls have been collected. Moreover, toshow the underground geoheritage, we provide a 3D model of the well and the surrounding area integrating a georeferenced laserscanner survey with ground-penetrating radar prospecting. We aim to obtain a tridimensional mapping of accessible internalrooms to depict the geological characteristics of the Etruscan Well, also revealing a surrounding network of buried galleries. Theresults are not only a meaningful advancement in the archaeological, geological and historical knowledge of the downtown ofPerugia but are a hint for the geoheritage promotion and dissemination, providing images and 3D reconstruction of undergroundarea
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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