1,721,047 research outputs found
Objective assessment of the WebP image coding algorithm
No full textResearch on multimedia data coding is allowing for better performance in terms of compression ratio, coding features, and robustness against transmission errors. While rate-distortion performance is being improved at a slower pace if compared to what we were used to up to a decade ago, remarkable advances are being made by adding complex features, such as fast adaptive transforms, lossy to lossless coding, compressed domain processing, etc. One of the latest codec which is expected to improve on the state of the art is the WebP algorithm released by Google. In this paper we provide an objective evaluation of WebP, by comparing it with the JPEG family algorithms. From the results it appears that the performance of the proposed codec is in line with that of the alternative methods, without achieving any major improvement and lacking several features
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
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
Dinamica sedimentaria dei fondali delle Bocche di Bonifacio (Sardegna settentrionale-Corsica meridionale)
No full textThis paper shows the results of “Bocche di Bonifacio” continental shelf mapping obtained by analyzing data collected during the oceanographic cruise "Bocche 2003" (Project “Geologia e geomorfologia terrestre e marina dell’insieme Corsica-Sardegna e della Toscana e applicazioni” - PIC- INTERREG III – Italia –Francia- Isole Sardegna – Corsica e Toscana, Asse 3 – Scambi transfrontalieri; Misura 3/1 scambi e cooperazione nel campo della ricerca). During the oceanographic cruise, performed aboard of the N \ O Universitatis, Multibeam, Side Scan Sonar and GeoChirp data were obtained. Moreover surface samples of mobile sediment, within depressions between -50 and -115 m, were collected. The analysis of both Side Scan Sonar sonograms mosaic and ultrasound paths, allowed us to perform a chronological and detailed mapping of various substrates highlighting the presence of complex bedforms associations. These bedforms associations are typical of continental shelf environment affected by high flow rate currents, both mono or bidirectional. Integrated digital data analysis associated to sedimentological study of sampled sediments, performed in a GIS environment, allowed to identify, in relation to the range time of the data acquisition, the directions of sediment movements on the seabed and the propagation sense of bedforms. Locally, it was found that the bedforms of mobile bottoms are still active and they persist for more than a decade. The path of currents circulation, during the acquisition data time, revealed the existence in the Bocche di Bonifacio channel of bottom currents flows westward, opposed to the prevailing flows of sea surface
Considerazioni sui risultati a distanza della laringectomia totale con svuotamento linfonodale latero-cervicale di principio
No full textDispelling the Myths Behind First-author Citation Counts
Full text linkWe 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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