1,721,515 research outputs found
The wide angle camera of rosetta
Get PDFRosetta was the ESA cornerstone missions which investigated the comet 67P/Churuymov-Gerasimenko. One of the on board instruments was the OSIRIS imaging system, which included the Wide Angle Camera. This camera was designed, realized, integrated, aligned and tested at the Padova University. Several challenges had to be faced and solved, due to stringent requirements and the very peculiar mission profile which foresaw a long interplanetary travel with very different thermal environments. Rosetta has been a very successful mission which returned plenty of fundamental information about comets and more in general about the solar system origin. In this paper we summarize the main characteristics of the WAC and describe one of the many scientific results that it had returned
Evaluation of an area-based matching algorithm with advanced shape models
No full textNowadays, the scientific institutions involved in planetary mapping are working on new strategies to produce accurate high resolution DTMs from space images at planetary scale, usually dealing with extremely large data volumes. From a methodological point of view, despite the introduction of a series of new algorithms for image matching (e.g. the Semi Global Matching) that yield superior results (especially because they produce usually smooth and continuous surfaces) with lower processing times, the preference in this field still goes to well established area-based matching techniques. Many efforts are consequently directed to improve each phase of the photogrammetric process, from image pre-processing to DTM interpolation. In this context, the Dense Matcher software (DM) developed at the University of Parma has been recently optimized to cope with very high resolution images provided by the most recent missions (LROC NAC and HiRISE) focusing the efforts mainly to the improvement of the correlation phase and the process automation. Important changes have been made to the correlation algorithm, still maintaining its high performance in terms of precision and accuracy, by implementing an advanced version of the Least Squares Matching (LSM) algorithm. In particular, an iterative algorithm has been developed to adapt the geometric transformation in image resampling using different shape functions as originally proposed by other authors in different applications
Gli immigrati nell’economia romana: lavoro, imprenditoria, risparmio, rimesse
No full textCamera di Commercio Industria Artigianato e Agricoltura Roma – Caritas di Roma, p. 255
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
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
Measurement of the second-order g(2) correlation function of visible light from Vega in photon counting mode
No full textThis paper illustrates the results of an experiment performed in the frame of the Asiago Observatory Stellar Intensity Interferometry program, aimed to exploit the quantum properties of the photon stream emitted from celestial objects. Data are acquired over two telescopes separated by approximately 4 km in photon-counting mode and analyzed in post-processing. The temporal and spatial correlation function g(2) on the bright star Vega has been successfully measured at zero baseline and at a ∼ 2 km baseline. The result is fully consistent with that expected for a source with the angular diameter of Vega (approximately 3.3 mas)
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
Quantum astronomy: Scientific background, technologies, achieved results, and future developments
No full textQuantum technologies have been introduced widely in different scientific fields and some industry application have been
developed. In this work we outline the history and development of a new field of Astronomy which is based on the
concept of quantum mechanics and takes advantage from the technological instruments developed recently for quantum
information in order to investigate new properties of the light coming from the sky. The development of this Quantum
Astronomy instruments is still very active (e.g. Adaptive Optics integration) and the scientific target is pushed to new
exiting limits: for example, periodic optical monitor of pulsars, lunar occultation; transit-occultations and application of
the Hanbury Brown Twiss Intensity Interferometry
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