1,721,679 research outputs found
Automatic three dimensional feature extraction: the case study of l'Aquila for collapse identification after April 2009
No full textThis paper illustrates an innovative methodology for post-earthquake collapsed building
recognition, based on satellite-image classification methodologies and height variation
information. Together, the techniques create a robust classification that seems to yield good
results in this application field. In the first part of this study, two different feature extraction
methodologies were compared, based respectively on pixel-based and object-oriented
approaches. Then the classification results of the most accurate classification methodology,
obtained on an eight band WorldView-2 monoscopic image, were completed with height
variation information before and after the event. The height difference is calculated,
comparing a photogrammetric DSM, obtained using a photogrammetric rigorous orbital
model on some EROS-B 0.7 metre across-track stereopairs with a ‘roof model’ before the
earthquake.
Keywords: image classification, L’Aquila earthquake, collapses, EROS-B, World-View-
Unmanned aerial vehicle for post seismic and other hazard scenarios
No full textOn April 6, 2009, an earthquake hits the old city of L’Aquila resulting in hundreds of victims and thousands of collapses. The post emergency and very crucial phase regarding surveys, structure controls and investigations till now is fully underway. Conventional surveying techniques using high precision total stations, GNSS and laser scanners, are instruments of extreme operability but here are still many evident limits on their use especially regarding the survey of both the roofs and the facades of tall buildings or dangerous places, typical in post earthquake situations. Another very important disadvantage of the traditional surveying, especially during the post seismic periods, regards the overall safety of the instruments, operators and workers. In particular, the seismic sequence that may last for months after the main shock, causing collapses and ulterior damage that in most cases can also damage the transport and communication infrastructure creating important problems for all instruments located in that area and definitely posing a further serious risk for all operators. Moreover, some surveys have to be repeated periodically in order to achieve a final result. On the other hand, by using micro UAVs (Unmanned Aerial Vehicles) for surveying in such particular scenarios, many of these problems can easily bypassed. For example, there are no accessibility problems for an UAV mainly because of its extreme flying capabilities that can really permit the access of virtually any place. Regarding the security, these instruments are fully remotely controlled, so they do not involve any risk for the operators simply because they are in the dangerous area. For these reasons, in this work, we’ll explain the advantages of multirotor UAVs, fully remotely controlled, to acquire roofs and facades of structures in an old city center damaged by a seismic sequence like L’Aquila city
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
Development of a software to optimize and plan the acquisitions from UAV and a first application in a post-seismic environment
No full textPermeabilità bronchiale transepiteliale. Basi anatomo-funzionali e implicazioni cliniche
No full textVariations 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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