1,721,030 research outputs found
Politiche locali, infrastrutture per lo sviluppo eprocessi di integrazione euro-mediterranea
No full textStochastic estimate of redundancy effects for non conventional ac locomotive traction drives
No full textThe direct connection of locomotive power electronics equipment to medium voltage ac overhead lines seems to be a practicable option today. Low frequency onboard transformers could therefore be eliminated, thus resulting in more efficient and lighter rail vehicles drive chains. However, the removal of the conventional transformer requires the development of innovative power conversion
architectures, which should be carefully analyzed in all respects. Aim of this paper is to evaluate, through a comparative analysis, the effectiveness deriving from the adoption of redundant configurations in a non-conventional ac loco traction drive, which allows the use of transformers of
greatly reduced size. Playing power electronics a fundamental role in the solutions analysed by the authors, a detailed analysis based on the Monte Carlo procedure has been carried out to compare the stochastic performances of the loco electrical drive systems under analysis, as a function of the reliability characteristics of their basic components
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
[Color Doppler echography of the orbit. Its normal aspects and pathological conditions with vascular involvement].
No full textThis study was aimed at investigating the role of color-Doppler US in the assessment of orbital vasculature under normal conditions; the results were then applied to the flowmetric analysis of some vascular diseases of the orbit, i.e., retinitis pigmentosa, simple chronic glaucoma, low-tension glaucoma and carotid-cavernous fistulas. The study consisted of two phases: first, a group of 20 healthy volunteers was examined and then 39 patients were divided into 4 subgroups. The patients (18 men and 21 women, age range: 52-68 years) were further divided into 4 subgroups: 12 of them had retinitis pigmentosa, 15 simple chronic glaucoma, 8 low-tension glaucoma and 4 carotid-cavernous fistulas. Color-Doppler yielded useful pieces of information on the position of orbital vessels and flow direction, while pulsed Doppler allowed the measurement of several variables, i.e., time average velocity, protosystolic velocity, peak systolic velocity, mesodiastolic velocity, end diastolic velocity, resistive index and pulsatility index. The study of the 20 healthy volunteers yielded valuable information on the anatomy and flow patterns of some vessels, such as the ophthalmic artery, the central retinal artery, the lacrimal artery and the posterior ciliary arteries, all of them visible in 90-100% of patients; the central retinal vein, the superior ophthalmic vein and venae varicosae were demonstrated in about 10-30% of them. In the group of patients, the mean flow velocities of the examined arteries were significantly lower than those in the normal volunteers; in the patients with carotid-cavernous fistulas an ectasic superior ophthalmic vein was demonstrated, with its typical flow "arterialization" pattern. The results suggest that color-Doppler could play a mayor role in the study of ocular hemodynamics.This study was aimed at investigating the role of color-Doppler US in the assessment of orbital vasculature under normal conditions; the results were then applied to the flowmetric analysis of some vascular diseases of the orbit, i.e., retinitis pigmentosa, simple chronic glaucoma, low-tension glaucoma and carotid-cavernous fistulas. The study consisted of two phases: first, a group of 20 healthy volunteers was examined and then 39 patients were divided into 4 subgroups. The patients (18 men and 21 women, age range: 52-68 years) were further divided into 4 subgroups: 12 of them had retinitis pigmentosa, 15 simple chronic glaucoma, 8 low-tension glaucoma and 4 carotid-cavernous fistulas. Color-Doppler yielded useful pieces of information on the position of orbital vessels and flow direction, while pulsed Doppler allowed the measurement of several variables, i.e., time average velocity, protosystolic velocity, peak systolic velocity, mesodiastolic velocity, end diastolic velocity, resistive index and pulsatility index. The study of the 20 healthy volunteers yielded valuable information on the anatomy and flow patterns of some vessels, such as the ophthalmic artery, the central retinal artery, the lacrimal artery and the posterior ciliary arteries, all of them visible in 90-100% of patients; the central retinal vein, the superior ophthalmic vein and venae varicosae were demonstrated in about 10-30% of them. In the group of patients, the mean flow velocities of the examined arteries were significantly lower than those in the normal volunteers; in the patients with carotid-cavernous fistulas an ectasic superior ophthalmic vein was demonstrated, with its typical flow "arterialization" pattern. The results suggest that color-Doppler could play a mayor role in the study of ocular hemodynamics
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