1,720,988 research outputs found
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
Investigation of Mould Filling and Solidification during Ingot Casting Process with Experiments and OpenFOAM Numerical Modelling
No full textThe fluid flow and solidification of ingot casting was studied. In this study, the fluid flow during the bottom teeming process was investigated with water model experiments and numerical simulation. A user-defined liquid-solid two-phase solidification solver was developed based on the software platform of OpenFOAM, using Euler-Euler two-phase approach. The solidification solver was performed on a 3-dimensional model of steel ingot to simulate the solidification and macrosegregation distribution.In water model experiments, water and vegetable oil were used to simulate the molten steel and slag phase, respectively. The influence of model parameters, such as the filling rate, nozzle dimensions and oil film thickness, on the filling conditions was investigated, concerning two aspects: one is the slag entrapment, and the other is reoxidation of molten steel. Both of the two situations should be avoid to provide a better filling condition. The numerical simulation on water-air two-phase flow with the interFoam solver of OpenFOAM was performed. The obtained predictions were in good agreement with the water model experiments. The simulation of solidification can obtain the evolution of the solid fraction, velocity, temperature, concentration and grain density fields. The macrosegregation was indicated by the concentration of the only solute − carbon. The cone-shaped negative segregation at the bottom, positive segregation at the top, V-segregation at the upper center of the ingot, and the channel-shaped A-segregation were predicted. The simulation results of macrosegregation ratio on certain lines were generally in agreement with the experimental measurements from the literature, except for some deviations at the bottom and the near-wall regions, where the predicted degree of negative segregation was much stronger than the measured one
Quality of as cast ingots with extreme large shapes
No full textThe quality of as-cast ingots and continuous cast products are controlled by solidification process mainly. Regarding to this, investigation on casting and solidification process of ingots and continuous cast products is considerable important in control of the quality of as-cast products especially for products with extremely heavy weight like several hundred tons. The present work focuses on the solidification process of large ingots. The complex solidification phenomena in large ingots have been investigated by means of three modelling methods, namely hot modelling, cold modelling and numerical modelling. In hot modelling, two series of ingot casting experiments has been performed for ingots with weight of 100 kg and 500 kg with various parameter combinations. The large ingots with weight of 500 kg solidify slowly in a specially designed isolating mould with the solidification time over several hours, and this slow solidification process simulates the solidification of industrial scale large ingots with weight between 3 to 6 t. Cooling curves have been measured by thermocouples during solidification, and as-cast structure and macrosegregation of solutes have been quantified. Based on this, solidification in large ingots has been investigated and three solidification regimes have been suggested and discussed. A-type Segregations could be produced in the laboratory for detailed studies.Meanwhile, water modelling (cold modelling) by using NH4Cl solution has been conducted with different cool conditions and initial solution temperature. A quasi 2-D water model has been built up with glass and aluminium, where hot saturated NH4Cl solution are poured in and crystallized subjected to cooling conditions. During precipitation of solid NH4Cl, phenomena such as dendritic growth and sedimentation of crystals are similar to those in ingots solidification, therefore NH4Cl solution is used as transparent analog to provide information of the solidification process in large ingots. Besides the experimental work, numerical modelling of ingot solidification has been performed as well. A two-phase solidification model based on volume-averaging-technique has been developed. This solidification model has been applied for the ingots with weight of 100 kg and 500 kg, and the simulation results have been compared with the experimental results regarding as-cast structure and macrosegregation. Furthermore, a channel-segregation model has been developed for the determination of the A-type segregation formation. The effects of carbon concentration and flow velocity of the solute enriched melt on the widening and closing of the potential channel have been investigated. Overall, solidification in large ingots has been investigated experimentally and numerically. The relationship among as-cast structure, local solidification driving force and solidification sequence in large ingots has been intensively studied, and the formation mechanism of A-segregation has also been explored
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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