1,721,001 research outputs found
ARTEMIdE - An Automated Underwater Material Recognition Method for Fluorescence LIDAR Invariant to Environmental Conditions
No full textThis article presents an automated underwater material recognition methodology for fluorescence light detection and ranging (LIDAR) invariant to environmental conditions (ARTEMIdE). Contrary to other state-of-the-art methods for submerged object recognition, ARTEMIdE can be applied when no a priori knowledge about environmental conditions is available and without resorting to any additional data besides the received signal and the fluorescence spectral signatures of the materials of interest. Experimental results over synthetic and real data show that ARTEMIdE is effective at automatically recognizing various object materials submerged at different depths within the water column. The presented approach reveals to provide great potential for many marine and submarine applications
Disruption of Hyperion and Origin of Titan's atmospheres
No full textTwo peculiar features of the Saturnian satellite system, that is, the dense, N2-dominated atmosphere of Titan, and the very irregular shape of Hyperion, are probably related to each other. Numerical integrations show that most fragments ejected after the catastrophic breakup of a presumably larger and nearly-spherical proto-Hyperion fell onto Titan over a time scale of 103 yr, at impact speeds <4 km/s. Such impacts resulted into accretion of the constituent volatile materials into Titan's atmosphere. If proto- Hyperion was ≍1000 km in diameter, the entire current atmosphere may have been generated by this impact shower. Even for a smaller total mass of the impactors, any pre-existing atmosphere must have been chemically reprocessed, producing large amounts of N2 by shock effects. Impacts by proto-Hyperion fragments are also likely to have formed giant impact basins on Titan's surface
Closed-Form Nonparametric GLRT Detector for Subpixel Targets in Hyperspectral Images
No full textThe generalized likelihood ratio test (GLRT) is here combined with the nonparametric approach to derive a new adaptive detector for subpixel targets in hyperspectral images. Specifically, a variable bandwidth kernel density estimator (KDE) is employed for estimating the conditional probability density functions composing the GLRT. Although KDE has generally a low mathematical tractability, an approximated closed-form solution is here derived, thanks to an innovative and uncommon choice for the kernel function. Experimental results in subpixel target detection scenarios show that the proposed detector represents not only the natural evolution of but also a successful alternative to both very widely employed and very recently proposed GLRT-based detectors
Ultrasound System Typologies, User Interfaces and Probes Design: A Review
Full text linkAbstractThe present review paper aims to give insights regarding what is available now, and will be in the next future, on the Market in terms of Ultrasound (US) system User Interfaces characteristics and peculiarities; US system typologies and probe typologies. Moreover, insights regarding ergonomics evaluation technologies and techniques for US systems, User Interface and transducers design evaluation, will be provided as well. The User interface ergonomics of US systems and probes is of primary importance due to the increased use in the everyday clinical practice even by non-sonographers, and the higher attention to the Work-related Musculoskeletal Disorders (WRMSD). A large overview and review of market data, side by side tests, websites, interviews to US users, marketing and sales professionals, scientific and educational publications was carried out in order to collect all available data as well as to show and describe them to the reader. Nowadays US market offers many different typologies of systems and probes, with different prices, features, quality level and targets of use. Users have to be aware to increase their level of knowledge in order to perform the best choice in terms of price/performance ratio and in terms of ergonomics and workflow requirements. The same level of knowledge is necessary also for other stakeholders of the US imaging Lab and purchasing/test decision phases such as Clinical and Biomedical Engineers involved in technical decision related to capital equipment and their maintenance. Final users expect technical innovations every 6-12 months in order to ensure technical-clinical improvements and company commitment to research and customer focus. Such characteristics are important clues showing a fast moving of the US market from a capital equipment basis to a more mass-consumer approach characterized by fast innovations, quick obsolescence and consumer prone attitude to system rotation in order to have always the more up-to-date technology, product, probe available on the Market
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
Correlazioni psiconeuroendocrine nell'infarto acuto del miocardio
No full textAspetti psiconeuroendocrinologici nell'IM
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
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