1,721,100 research outputs found
Zenith total delay interpolation to support GNSS monitoring of potential precipitations
No full textA useful contribution to atmosphere monitoring may be provided by the analysis of GNSS (Global Navigation Satellite System) signals. The authors have identified a procedure to monitor in space and time the Precipitable Water Vapor (PWV) content on regionally extended and orographically complex area. The starting point of the procedure is the local estimation of Zenith Total Delay (ZTD) on a GNSS Permanent Stations network, observed from existing infrastructures and integrated with Pressure and Temperature data to produce PWV maps. The present paper deals with the identification of the most appropriate technique to interpolate ZTD, to create maps in quick and automatic way for near realtime application, in order to support the monitoring of intense meteorological events. The main difficulties are due to the sparse distribution of data, combined with high resolution and wide computational region. ZTD has been interpolated through the methods implemented in GRASS GIS: Inverse Distance Weighted, Regularized Spline with Tension, Ordinary Kriging and Triangulated Irregular Network
AN INTEGRATED MONITORING SYSTEM THROUGH 3D LASER SCANNER AND TRADITIONAL INSTRUMENTS FOR LOAD TEST ON ARCH BRIDGE
Full text linkThe experimental campaign represents an example of how the careful design of the different test phases and the choice of the needed
instrumentation are fundamental aspects to obtain a proper interpretation of the results, for future application on the real structures.
Additionally, the present work represents a successful example of a combined monitoring system, integrating the traditional and
innovative technical instrumentation for loading tests and geomatics survey techniques. The monitoring system has been designed
with the aim of defining the load carrying capacity of a masonry arch bridge scaled model and to test the performances of a new
retrofitting method. In particular, two different configuration have been considered: a first one with isolated arch and a second one
with gravel fill on the arch
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
Spatial interpolation techniques for near real-time mapping of Pressure and Temperature data
No full textAmong the different techniques for atmosphere monitoring, the GNSS (Global Navigation Satellite
System) can provide an innovative contribution (Bevis et al., 1992; Crespi et al., 2004; Sguerso et al.,
2013, 2015). The Laboratory of Geomatics, Geodesy and GIS of the University of Genoa has identified a
GIS procedure and a simplified physical model to monitor the Precipitable Water Vapour (PWV) content,
using data measured by existing infrastructures. The starting points are local estimations of Zenith Total
Delay (ZTD) from a GNSS Permanent Stations (PSs) network, a Digital Terrain Model (DTM) and local
Pressure (P) and Temperature (T) measurements (Sguerso et al., 2014; Ferrando et al., 2016). The
present paper shows the study of the most appropriate interpolation technique for P and T data to create
PWV maps in a quick, stable and automatic way, to support the monitoring of intense meteorological
events for both a posteriori and near real-time applications. The resulting P and T maps were compared
to meteorological re-analysis, to check the reliability of the simplified physical model. Additionally, the
Regression Kriging (RK) was employed to evaluate the data correlation with elevation and to study the
applicability of the technique
U.ph.o and mago: Two useful instruments in support of photogrammetric uav survey
No full textIn emergency and critical scenarios, the UAV could play a key role in accessing unreachable sites in a safe and rapid way, guaranteeing at the same time the necessary accuracy and precision of the survey. In this context, UAV survey campaigns have been performed by the authors in Norcia (Italy), hit by tragic seismic events in August and October 2016. The surveys were motivated by the artistic and historical value of monuments, the need to plan and design the restoring and retrofitting of buildings, and also to quantify and manage the ruins. Goal of such surveys was the description of the structures geometry with a centimetric precision and a high level of reliability. Recently, the authors have conceived two tools, U.Ph.O (Unmanned Photogrammetric Office) and MAGO (Adaptive Mesh for Orthophoto Generation), dedicated to the planning and restitution phases of the survey, respectively. U.Ph.O. and MAGO are here applied to two different buildings in Norcia, i.e. the Civic Tower of Norcia and San Salvatore Church of Campi di Norcia. The former is a standing-out structure, surrounded by the complex of the historical centre, while the latter is located in an isolated site in the countryside. These features make the survey planning and the orthophoto reconstruction completely different, mainly due to the different optimal shooting geometry and the presence or absence of obstructions
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