1,721,151 research outputs found
Eloisa Morra (a cura di), Paesaggi di parole. Toti Scialoja e i linguaggi dell’arte
Full text linkRecensione a Eloisa Morra (a cura di), Paesaggi di parole. Toti Scialoja e i linguaggi dell’art
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
Radiologic evaluation in planning surgery of renal tumors
No full textThe evolution in diagnostic imaging modalities, mainly in computed tomography (CT) and magnetic resonance imaging (MRI), have made it possible to extend the applications of these techniques from diagnosis to staging and surgical planning. Nowadays, the possibility to present images on different planes with an intrinsic resolution close to that of the original axial sections allows presentation of the kidney on sagittal, coronal, and oblique planes. Three-dimensional reconstructions can be obtained with different methods and have attained excellent image quality. Multidetector spiral CT presently is the best technique for planning surgery, but MRI also enables high-quality images to be obtained if state-of-the-art equipment is available. This update reviews the current status and possibilities of diagnostic imaging modalities in planning surgery of renal tumors
New automatic software for virtual colonoscopy: technical aspects.
No full textPURPOSE:
To evaluate a new virtual endoscopy software package capable of automatically plotting the path along which to perform endoscopic exploration.
MATERIALS AND METHODS:
We reviewed the examinations of 50 patients with colonic neoplasms studied by CT colonoscopy by using a single-detector CT scanner (Philips Tomoscan AVE1). The technical parameters used were: slice thickness 3 mm, pitch 1.4, reconstruction interval 2-2.5, 120 kV, 150-200 mA. The images were processed on a separate workstation (Philips Easy Vision 5.1) running an experimental virtual endoscopy software package capable of automatically drawing a line along which to move the virtual endoscope to explore the colon. Reconstruction of the endoscopic images along the path obtained was set at an interval of 15-20 mm between one endoscopic view and the next, to a total of 70 to 120 images. The endoscopic animated image sequence was then saved and evaluated by comparing the starting axial images and the three-dimensional images obtained.
RESULTS:
The programme plotted the endoscopic path correctly in a single pass in 40 of the 50 cases studied. The overall time spent by the radiologist on image-processing did not exceed 5 minutes.
DISCUSSION:
The need to reduce the time spent by audiologists on post-processing has led to a gradual improvement in image-processing hardware and software. In the context of virtual endoscopy, one of the main goals is to obtain the path for endoscopic exploration in as short a time as possible. The programme we evaluated successfully fulfils this requirement as, once the image-processing technical parameters have been defined, it plots a path along the entire colon and performs the reconstruction procedures automatically. The time spent by the operator on post-processing does not exceed 5 minutes.
CONCLUSIONS:
The new programme evaluated in this study facilitates the processing of endoscopic images, reduces radiologist time and may contribute to the widespread use of virtual colonoscopy
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
Dispelling 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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