1,720,968 research outputs found
Geomorphological mapping and mass-wasting analysis in complex landslides using Terrestrial and Airborne LiDAR
No full textHigh-Resolution Digital Elevation Models (HR DEMs) obtained with Light Detection and Ranging technology,
(LiDAR) have proved to be useful in the analysis of landslide processes in mountainous terrains, for different
purposes and at different spatial scales, including improvement of landslide inventories, susceptibility assessment
and appraisal of landslide geomorphic features. The application of laser scanning techniques results in data
sets with enormous data size, extremely high accuracy (up to cm-scale) and very high spatial resolution. The
exploitation of HR DEMs in landslide analysis can be manifold, comprising automated spatial data processing as
well as expert knowledge - supervised procedures.
First goal of this paper is to stress the advantages given by the usage of Shaded Relief datasets obtained from HR
DEMs in geomorphological mapping of complex landslides. Through the use of such datasets, surveyors gain an
enhanced capacity to identify slope-scale geomorpho-dynamic units, the possibility to increase the precision of
scarps and detachment areas zonation, the capacity to identify and map compressive and extensional features all
across the landslide body, and the possibility to retrieve other relevant geomorphological indicators of movement.
These advantages are exemplified by presenting maps of large-scale earth slide – earth flows and deep seated rock
slides located in the Alps and in the Apennines, that have been obtained by making use of shaded relief maps
calculated from regional and local datasets using different scene illumination parameters.
Second goal of this paper is to exemplify the usage of Differential HR DEMs is mass-wasting analysis applied
to active earth slides - earth flows located in the northern Apennines. This simple DEM subtraction procedure
can be carried out using multi-temporal airborne or terrestrial surveys, or by fusing airborne and terrestrial data.
Examples are presented of landslides for which mass wasting at the slope scale and total volumetric magnitude of
the events have been assessed using both single-type and fused-type data sources. Disregard possible uncertainties,
these pieces of information helped in depicting possible future scenarios. Moreover, considering that earth slides
– earth flows moving at a rate up to 10 m/day are difficult to be monitored with classical in situ instrumentation,
the results suggest that LiDAR systems could also be used, under certain organizational conditions (temporal
resolution of the surveys, costs, post-processing efforts etc.), as a near-real time monitoring system during and
after reactivation events
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Continuous monitoring of active rock blocks slide in the northern Apennines
No full textA large and morphologically spectacular rock slope instability is detected in the northern Apennines of Italy. Ten
of metres of blocks and columns, in calcareous rock formation, slide and spread on clay shale, dipping down slope
30°.
The geological structures and the morphological features of the slope deformation have been identified with use
of high-resolution digital elevation models obtained from ground based laser scanner and airborne LiDAR.
The actual morphological setting of the slope is characterized, also far away form the main scarp, by some metres
high columns in vertical position. This suggests that the main deformations are parallel to the slope. Inside the
landslide, rock falls are also frequent, due to the failure of large blocks and columns through set of joints.
The origin of the instability is probably related with the erosion of the clay formation, at the foot of the slope, by
the close torrent. From the analysis of aero-photographs of the past fifty years is possible identified an enlargement
of the mass instability in the up slope direction. A destructive event was recognized in the Seventies, when the
road and the bridge below the landslide were destroyed. During the event was documented the passage between
slow to very fast moving.
In the summer 2009, after the increase of the slope deformations of the last years, a continuous monitor system
was installed. The system is a robotic station that every two hours measures 20 benchmarks fixed in the rock
blocks and columns in the landslide area. Today, tens centimetre of displacements are recorded. The data show an
increase of the deformations rate with the distance from the main scarp. At the moment, the evolution of the slope
is controlled by continuous creeping processes and by period with accelerates deformations. These last correlate
with wet and snow melt periods, which are responsible of the variation in the groundwater regime and of the
changes in the material behaviour within the sliding zon
Variations on the Author
Get PDF“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
Terrestrial Laser Scanning for Preserving Cultural Heritage: Analysis of Geometric Anomalies for Ancient Structures
No full textIdentifying the overhang, progressive changes of inclination, differential movements of the structure and detailing the study of structural elements are just some examples of the many fundamental information for structural engineers. Those data are required to study and analyze the behavior of a structure with the purpose to assess the stability . Laser scanning appears to be the best technology to provide an effective solution to those requirements. Surveying by means of a terrestrial laser scanner (TLS), allows to detect a huge number of information with relatively short time and high accuracy. Those data, then, do not necessarily need to be used to reconstruct the three dimensional surface model. Just analyzing the point clouds, interesting information along with useful products can be obtained in order to draw some considerations about the investigated structure. This research aims to suggest a new philosophy for using TLS in a diagnostic perspective in order to study structures along with their actual dimensions, their stability and so on. This new approach, characterized by a well- advanced vision, is really different from the traditional one because of the engineering point of view with respect to the usual application of TLS. Traditionally, indeed, laser scanning is chosen for artistic and architectural studies and the resulting three-dimensional model represents what often is of concern.The research focuses on the Cathedral of Modena, one of the most important pieces of Romanesque culture in Europe (UNESCO World Heritage List since 1997). The overall motivation of this research is to preserve the cultural heritage we are responsible for, as long as spectators. Thus, the final purpose is to illustrate the methodology to compute anomalies in structural geometry by means of TLS in order to provide an accurate description of the structure that is particularly useful for structural engineers, architects and art historians. Both outdoor as well as indoor TLS surveys were performed. The geometry of the structure was properly described by analyzing point clouds; specific measurements were focused on constituent elements with the aim of detecting anomalies of the geometric configuration. Geometric anomalies might be read as the result of deformations occurred in the past or as future deformations due to an abnormal geometric configuration. Investigations about the identified anomalies will be presented together with differential movements obtained by high precision leveling focused on a network of benchmarks that were installed along the outside perimeter. The integration of independent techniques allows to check for consistency of results
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
Get PDFWe 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
- …
