1,720,996 research outputs found
Experimental Tests on the Benefits of a More Rigorous Model in IMU/GPS System Calibration
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Methodological Report on Emergency Surveys for Cultural Heritage
No full textThe management of emergency scenario is a very complex issue, due to the risk of recurrence of the calamity itself. The present work is intended as a methodological report based on the gained professional and scientific experience of the authors, involved in the survey of several Cultural Heritage buildings hit by the earthquakes that afflicted Central Italy in 2016. The examined structures include the Civic Tower in Norcia, the co-cathedral Santa Maria Argentea and the San Salvatore church in Campi di Norcia. The survey campaigns were performed immediately after the aftershocks occurred in the end of October, on behalf of the Italian Ministry that at the time was called of Cultural Heritage and Activities and Tourism (MiBACT), in order to ease the securing of the sites and their restoration. Because of the necessity to provide the survey products as quickly as possible, typical in an emergency situation, particular attention was paid to optimize both the on-site and the post-processing phases, with respect to the required accuracy. In this regard, U.Ph.O. (Unmanned Photogrammetric Office), a tool developed during the Ph.D. thesis work of one of the authors, is particularly useful for the a priori evaluation of the realistic accuracy obtainable during a photogrammetric survey. In the present work, this tool was applied to the San Salvatore Church, taken as case study to check the influence on the photogrammetric products of two of the main planning parameters: the image overlapping and the accuracy in Unmanned Aerial Vehicle (UAV) positioning
Pervasive developmental disorders and GABAergic system in patients with inverted duplicated chromosome 15
No full textPervasive developmental disorders are characterized by severe, pervasive impairment in several areas of development, with distorted communication skills and stereotypical behavior. Pervasive developmental disorders have a heterogeneous etiology related to brain damage, familial affective psychopathology, chromosomal abnormalities, or dysfunction of neuromodulators. Recently, it has been suggested that the GABRB3 gene, located within chromosome 15q11-13, is a candidate for pervasive developmental disorder. In inverted duplicated chromosome 15 syndrome, in which there is a small marker chromosome derived from inversion and duplication of the chromosome 15q11-q13 region, all patients present with pervasive developmental disorder. To further investigate a possible involvement of the gamma -aminobutyric acid (GABA)ergic system in the inverted duplicated chromosome 15 syndrome, we evaluated plasma levels of GABA and diazepam binding inhibitor in 6 patients with inverted duplicated chromosome 15 and in 8 subjects not affected by neurologic disease. Our findings do not seem to support this hypothesis as no significant differences were found in the GABA and diazepam binding inhibitor plasma levels between patients with inverted duplicated chromosome 15 and controls, but we must consider the possibility that a genetic abnormality of the GABA(A) receptor could be present in patients with inverted duplicated chromosome 15 and still not be reflected in an alteration in either GABA or diazepam binding inhibitor levels in plasma
LOW-COST UAS PHOTOGRAMMETRY for ROAD INFRASTRUCTURES' INSPECTION
No full textAll over the world, road infrastructures are getting closer to their life cycle and need to be constantly inspected: a consistent number of bridges are structurally deficient, and the risk of collapse can no longer be excluded. In contrast with the past, the interest in structure durability has recently grown rapidly. In order to make bridges durable, it is necessary to carry out ordinary maintenance, preceded by inspection activities, which can be traditionally divided in two categories: destructive and non-destructive (NDT). All the NDT inspections (visual, IR thermography, GPR) can be conducted by using UAS (Unmanned Aerial Systems), a technology that makes bridges inspections quicker, cheaper, objective and repeatable. This study presents the visual inspection and survey of two bridges by using a UAS DJI Mavic 2 Pro, equipped with a 20Mpixel Hasselblad camera that records 60fps 4K video and a 10bit radiometric resolution. Starting from the acquired data, a 3D model of each structure was built by using Structure from Motion (SfM) principles and software. To validate the two models, each of them characterized by a centimetric accuracy, the UAS camera generated cloud of points and was co-registered with the point cloud of a terrestrial laser-scanner using Ground Control Points (GCPs). To make this, CloudCompare comparison software was used; the plugin M3C2 automatically calculates the distance between the points of two compared clouds. Finally, some general rules concerning the UAS main characteristics for inspection of bridges and software for data processing are proposed
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
EVALUATION of AIRBORNE IMAGE VELOCIMETRY APPROACHES USING LOW-COST UAVS in RIVERINE ENVIRONMENTS
No full textTraditional flow velocity measurements in natural environments require contact with the fluid and are usually costly, time-consuming and, sometimes, even dangerous. Particle Image Velocimetry allows the flow velocity field to be remotely characterized from the shift of intensity patterns of sub-image areas in at least two video frames with a known time lag. Recently, Airborne Image Velocimetry has enabled the surface velocity field of large-scale water bodies to be determined by applying Particle Image Velocimetry on videos recorded by cameras mounted on unmanned aerial vehicles. This work presents a comparison of three Airborne Image Velocimetry approaches: BASESURV, Fudaa-LSPIV and RIVeR. For the evaluation, two nadiral videos were acquired with a low-cost quadcopter. The first was recorded under low flow and seeded conditions, the second during a flood event. According to the results obtained, BASESURV is an accurate and complete research oriented approach but it is time-consuming and neither a graphical interface nor documentation are yet provided. Fudaa-LSPIV is a well-developed software package, with a user-friendly graphical interface and good documentation. However it lacks some features and the source code is closed. RIVeR may be suitable for real time monitoring thanks to the rectification of velocity vectors only. Overall, all the codes are found to be effective in performing Airborne Image Velocimetry in riverine environments
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
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