1,721,079 research outputs found
A study on a position sensitive time of flight detector based on a neural network signal processing
No full textThe capabilities of a position sensitive time of flight scintillator (TOF-PS), viewed by an array of subminiature PMTs and based on a neural network signal processing, are studied. For each PMT, time and charge informations are fed to an artificial neural network to define on-line the event position. The first prototype of this detector consists of two 1.5 cm X 1.5 cm X 100 cm scintillator strips viewed by four directly coupled subminiature PMTs. A TOF time resolution of 166 ps and a spatial resolution of 2 cm (single counter) have been achieved
A study on a position sensitive time of flight detector based on a neural network signal processing
No full textInfluence of abdominal surgery on pulmonary atelectasis formation in dogs
No full textThe aim of this study was to evaluate the influence of abdominal surgery on atelectasis formation in healthy dogs. After the induction of general anesthesia (GA), 20 dogs, scheduled for elective ovariohysterectomy, were positioned in dorsal recumbency: 10 dogs underwent immediate surgery (S group), while 10 dogs (NS group) were maintained under anesthesia for 60 min before surgery. In both groups, a helical computed tomography (CT) scan of the thorax and an arterial blood gas analysis were performed 60 min after the induction of GA. Lung aeration was estimated by analyzing the radiographic attenuation of the CT images. The atelectasic and poorly aerated lung compartments were significantly larger, and the normally aerated lung compartment was smaller in the S group compared to the NS group. The PaO2 was similar in both groups. Abdominal surgery significantly increases pulmonary atelectasis in healthy dogs under GA
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
Cooperative neural system for particle classification in a cosmic ray space experiment
No full textA modular classification system based on neural networks, for the particle identification task in a physics experiment, is proposed. The system is oriented to prevent systematic classification errors that could occur analysing experimental data with different statistical feature distribution in respect of the expected ones. The system has been investigated in the context of the positron/proton classification problem in a cosmic ray space experiment, where the physics detectors are faced by the critical flight conditions. Finally, the experimental results shows as an adaptive training based on the real data can improve the classification model of the system
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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