1,720,969 research outputs found
Nanoseismic monitoring of gravity-induced slope instabilities for the risk management of an aqueduct infrastructure in Central Apennines (Italy)
No full textA monitoring system is operative in the Peschiera Springs slope (Central Apennines, Italy) to mitigate the landslide risk related to the hosted main drainage plant of Rome aqueducts by providing alert warning. Such a strategy allows to avoid out-of-service episodes so reducing extra-costs of water distribution management. The Peschiera Springs slope is involved in a rock mass creep characterized by an average steady strain rate of 1 mm year-1 and responsible for several landforms including sinkholes, subvertical scarps and trenches. Moreover, an average aquifer discharge of 19 m3 s-1 causes an intense limestone dissolution concentrated in correspondence with release bands and discontinuities that dislodge the jointed rock mass. Since 2008, an accelerometric network has been operating within the slope; about 1300 microseismic local events were recorded up to now, distinguished in failures and collapses. A control index, based on frequency of occurrence and cumulative energy of the recorded microseismic events was defined to provide three levels of alert. In 2013, a temporary nanoseismic Seismic Navigation System (SNS) array was installed inside a tunnel of the drainage plant to integrate the pre-existent seismic
monitoring system. This array allowed to record 37 microseismic events, which locations are in good agreement with the evolutionary geological model of the ongoing gravitational slope deformation. In 2014, a permanent nanoseismic SNS array was installed in the plant
and allowed to record several sequences of underground collapses including more than 500 events. The nanoseismic monitoring system is allowing to: (1) increase the detection level of the monitoring system; (2) locate hypocentres of the events; and (3) detect precursors of
the strongest events
Seismic monitoring of the gravity-induced deformation involving the Peschiera Spring slope (Italy) for the management of a main infrastructure
No full textThe Peschiera Spring slope (Central Apennines, Italy), which hosts the tunnels of the main drainage plant of Rome aqueducts, is involved in a gravity-induced slope deformation. An average aquifer discharge of about 18 m3/s is responsible for an intense limestone dissolution corresponding to the main kinematic elements that dislodge the jointed rock mass. Since 2008 a seismometric network was installed within the tunnels of the drainage plant for detecting local underground instabilities consisting of failures and collapses. About 1000 signals due to instabilities were recorded up to now. A control index (CI), based on both the frequency of occurrence and the cumulative energy of the recorded local instabilities was tested for providing three levels of alert. During the 2014 a total of 32 collapse crises were recorded, that caused several “emergency” states of the plant
Experiment of an innovative nanoseismic monitoring applied to gravity-induced slope instabilities in a karstified rock mass
No full textThe Peschiera Springs slope (RI), which hosts the drainage plant of
the Rome’s aqueduct, is affected by a gravitational slope deformation
process, that is responsible for a rock-mass lateral spreading,
associated to several landforms including sinkholes, subvertical scarps
and trenches. An experiment, based on an innovative method of
monitoring, was carried out to record microseismic events generated
by underground instabilities such as failures and collapses. At this aim
a SNS (Seismic Navigation System) array was installed during the
year 2013 inside a the tunnel of the drainage plant in order to carry out
a continuous monitoring. The nanoseismic monitoring, allowed to
record 37 microseismic events. The seismic records were managed by
NanoseismicSuite software that allowed to identify and characterize
two different typologies of events: 19 underground collapses and 18
underground failures. The locations of these events are in good
agreement with the evolutionary geological model of the ongoing
gravitational slope deformation, i.e. with the spatial distribution of the
main trenches and scarps on the slope
Microseismicity due to gravity-induced rock-mass deformations and a related alarm system
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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