1,720,973 research outputs found
Development of a new mean value model for the analysis of turbolag phenomena in automotive diesel engines
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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
The effect of rosiglitazone on the liver: Decreased gluconeogenesis in patients with type 2 diabetes
No full textAims/Hypothesis: Diabetic hyperglycemia results from insulin resistance of peripheral tissues and glucose overproduction due to increased gluconeogenesis (GNG). Thiazolidinediones have been shown to improve glycemic control and increase peripheral insulin sensitivity. Whether chronic thiazolidinedione treatment is associated with a decrease in GNG has not been determined. Materials and Methods: We studied 26 diet-treated type 2 diabetic patients randomly assigned to rosiglitazone (RSG; 8 mg/d; n=13) or placebo (n=13) for 12 wk. At baseline and 12 wk, we measured endogenous glucose production (by [(3)H] glucose infusion) and GNG( by the [(2)H](2)O technique) after a 15-h fast. Peripheral insulin sensitivity was evaluated by a two-step (240 and 960 pmol/min/m(-2)) euglycemic insulin clamp. Results: Compared with placebo, RSG reduced fasting plasma glucose (9.7 +/- 0.7 to 7.4 +/- 0.3 mmol/ liter; P<0.001), fasting fractional GNG (-15 +/- 4%; P=0.002), and fasting GNG flux (-3.9 +/- 1.2 mu mol/min/kg fat-free mass; P=0.004), with no effect on glycogenolytic flux. Changes in GNG flux and fasting glucose were tightly correlated (r=0.83; P<0.0001). During both clamp steps, RSG enhanced insulin-mediated glucose clearance (by 26% and 31%; P=0.01 and P<0.02, respectively). In a subgroup of patients studied with magnetic resonance imaging, the reduction in GNG flux was correlated (r=0.65; P<0.02) with the reduction in visceral fat area. Conclusion/Interpretation: RSG increases peripheral tissue insulin sensitivity and decreases endogenous glucose release via an inhibition of gluconeogenesis
Analysis of the performance of a turbocharged s.i. engine under transient operating conditions by means of fast running models
No full textThe aim of this work is the assessment of the predictive capabilities of fast running models, obtained through an appropriate reduction and simplification process from detailed 1D fluid-dynamic models, for a turbocharged s.i. engine under highly transient operating conditions.
Simulations results have been compared with experimental data for different types of models, ranging from fully detailed 1D fluid-dynamic models to map-based models, quantifying the degradation of the model accuracy and the reduction in the computational time for different kinds of driving cycles, from moderately transient such as the NEDC to highly dynamic such as the US06.
Although the map based approach was confirmed to be be a viable means to predict fuel economy over the NEDC cycle, even for a downsized and turbocharged engine, thanks to the low accelerations involved and to the almost negligible transients effects, it showed significant discrepancies (error higher than 5%) with the experimental data when applied to highly dynamic driving cycles such as the US06.
On the other hand, the use of fast running models was demonstrated to be a suitable solution to obtain a satisfactory accuracy in the estimate of the fuel consumption also over highly dynamic driving cycles, with differences between the simulation results and the measured values which were within the repeatability range of the experimental tests. Moreover, the reduced computational effort of the fast running models allowed to reach close to real-time simulation performance
Determination of the enrichment of the hydrogen bound to carbon 5 of glucose on (H2O)-H-2 administration
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