1,720,966 research outputs found
Una Discussione sulla Determinazione del Campo di Vento sulla Superficie del Mare mediante SAR
No full textLa conoscenza del campo di vento sulla superficie del mare è di fondamenta- le importanza per la predizione e comprensione dei processi meteorologici nonché climatici. Il telerilevamento ha permesso di superare le tecniche tradizionali in situ grazie al vantaggio di operare misure più fitte sia da un punto di vista spaziale che temporale. Usualmente si realizzano queste mappe di campo di vento mediante l’inversione di dati scatterometrici. Per supera- re le limitazioni legate alla risoluzione spaziale degli scatterometri si sono recentemente proposte delle nuove tecniche di inversione di dati SAR (Radar ad Apertura Sintetica). In questo lavoro si illustrano i fondamenti fisici del problema e si presentano e discutono le tecniche basate sull’inversione dei dati SAR
SeaWinds Data Inversion
No full textScatterometers are radar properly designed to measure accurately the sea surface
roughness anisotropy due to the local wind field. Scatterometer data inversion calls for significant
processing. A new inversion scheme, developed at the Laboratorio di Telerilevamento
Ambientale, Università di Napoli Parthenope, to retrieve the wind field by Ku-band pencilbeam
SeaWinds scatterometer data is presented. Experiments on real data show the effectiveness
of the inversion
A Review of Sea Wind Vector Retrieval By Means of Microwave Remote Sensing
No full textWind vector over the sea is fundamental to pre- dict and understand meteorological and climatic processes. Mi- crowave remote sensing is able to make measurements that can be processed to estimate the wind vector. This ensures a better spatial and temporal coverage with respect to the traditional in situ techniques. At the present state-of-art, the operational tech- nique is associated to scatterometer, but new techniques, based on polarimetric radiometer and Synthetic Aperture Radar (SAR), have been also suggested. This paper is a review of all these techniques
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
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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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