1,721,010 research outputs found
Conferma della presenza di Aphanius fasciatus (Valenciennes, 1821) (Cyprinodontiformes Cyprinodontidae) nel bacino idrografico del Fiume Imera Meridionale (Sicilia)
No full textUn’abbondante popolazione del Ciprinodontide autoctono Aphanius fasciatus è stata rinvenuta
nel Fiume ImeraMeridionale ed in alcuni suoi affluenti. É così confermata la persistenza della specie
nel sito, nonostante le pesanti alterazioni ambientali che hanno interessato il fiume e che avevano
fatto ritenere A. fasciatus localmente estinto. Trattandosi di una delle poche popolazioni di
Aphanius fasciatus sopravvissute nei corsi d’acqua siciliani e alla luce della notevole diversità genetica
e morfologica riscontrata tra le differenti popolazioni siciliane di questo Ciprinodontide, la
sopravvivenza di questa popolazione assume un’importante valenza conservazionistica
Hyperspectral and multi-angle CHRIS proba images for the generation of land cover maps
No full textAbstract—The small hyperspectral imager Compact High-Resolution Imaging Spectrometer (CHRIS) is the most important instrument for Earth observation included in the payload
of the European Space Agency Third-Part Mission Project for On-Board Autonomy (PROBA)-1 satellite. This instrument has
provided dozens of images in several target areas in the world, and a good number of acquisitions are available for the test site
of Frascati and Tor Vergata, Italy. This paper reports several results concerning the generation of thematic maps obtained from
CHRIS mode-3 imagery. The potential of the use of different configurations for the input vector exploiting multispectral, multiangular, and multitemporal measurements has been investigated, and the results have been evaluated and compared in terms of
accuracy in the classification. The core of the decision task has been developed using the neural network methodology. Indeed,
this approach is characterized by a particular ease in performing nonlinear mapping of a multidimensional set of inputs into the output one
Feature reduction of hyperspectral data using autoassociative neural networks algorithms
No full textIn this paper Autoassociative Neural Networks (AANN) are used to implement Nonlinear Principal Component Analysis (NLPCA) for dimension reduction of hyperspectral data. The nonlinear components are then considered as inputs for a Multi-Layer Perceptron (MLP) network to perform pixel-based classification. The methodology has been applied considering the test area of Tor Vergata - Frascati, Italy, and the hyperspectral data provided by the CHRIS-PROBA mission. Comparative analysis with a similar procedure considering a more standard dimensionality reduction technique such as Principal Component Analysis (PCA) has been carried ou
Autoassociative neural networks for features reduction of hyperspectral data
No full textn this paper the potential of neural networks has been applied to hyperspectral data and exploited either for classification purposes or for data feature extraction and dimensionality reduction. For this latter task, a topology named autoassociative neural network has been used. In its complete form, the processing scheme uses a neural network architecture consisting of two stages: the first stage reduces the dimension of the input vector while the second stage performs the mapping from the reduced input vector into the land cover classification. The effectiveness of the feature extraction algorithm has been evaluated for a set of experimental data provided by the AHS radiometer comparing its performance to that obtainable with more traditional linear techniques such as PCA, while the accuracy of the final classification map has been computed on the base of the available ground-trut
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
IMPORTANZA DEI FRAMMENTI DI HABITAT NATURALE PER LE COMUNITÀ DI FILLOMINATORI (INSECTA DIPTERA, LEPIDOPTERA ET HYMENOPTERA) E LORO PARASSITOIDI (HYMENOPTERA EULOPHIDAE).
No full textVariations on the Author
No full text“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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