1,720,989 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
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
Epoxy methyl soyate as bio-plasticizer : two different preparation strategies
Full text linkDue to the recent rise in production costs of biodiesel and considering the necessity to use
environmentally friend production way, bio-plasticizers obtained from vegetable oils were developed. Bioplasticizer
are essentially constituted by epoxidized vegetable oils (EVO) (rich in unsaturated compounds
as soybean, sunflower and rapeseed oils).These kind of products have got good plasticizer properties and
are easily biodegraded by microbial agents. The main advantages of these additives are their low diffusion
coefficients in the polymeric matrix and a very low volatility. In recent years epoxidised fatty acid methyl
esters (EME) have been developed, because they are more soluble and confers better flexibility to the
plastic even at low temperatures. The main problem associated with these products lies in their content of
satured methyl esters. This fraction cannot be epoxydised and has got a very low affinity with the
polymeric matrix, so that tends to migrate at the plastic surface giving not desired properties to the final
products. The aim of this work is to find the best reaction conditions in terms of epoxide yield, using acetic
acid and hydrogen peroxide, and to apply these condition either to 1) a fractionated biodiesel (i.e. without
satured esters) or 2) to soybean biodiesel in order to obtain EME and then distillate it to remove the
unreacted esters. Both the strategies were studied by experimental batch epoxidation test and vacuum
distillation runs. A better bio-plasticer was obtained (epoxide number of about five) using the first strategy,
i.e. by a distillation of starting biodiesel, perfomed at 0.5 torr using a two equilibrium stage batch distillation
apparatus, followed by the epoxidation reaction
Reasoning With Worlds and Truth Maintenance In An Intelligent Tutoring System
No full textOne of the distinguishing features of Intelligent Tutoring Systems (ITS), and a winning point over traditional Computer-aided Instruction (CAI) systems, is that ITSs are endowed with problem-solving capabilities in the domain to be taught. In this article, we describe the use we have made of a particular inferential mechanism, based on a context system associated with a truth maintenance syste, for building an expert system in education. In particular, we present the use of such tools in the design of the expert module of SAMPLE, an ITS for teaching high school and college students how to analyze electrical circuits in alternate current in a steady condition. We stress the capability of the system of determining all the possible solutions to a given problem even if it is proposed by a student
Porcelain gres tiles with photocatalytic properties for a better environment
Full text linkPorcelain gres tiles are characterised by their very low water absorption rate of less than 0.5%, and are manufactured under high pressure by dry-pressing fine processed ceramic raw materials with large proportions of quartz, feldspar and other fluxes. Afterwards, the body of these materials is fired at high temperatures (1200 - 1300°C) in a roller kiln. The final material is characterized by lack of porosity, durability, high breaking and wear resistance properties and a complete frost resistance.
In the past decades porcelain gres tiles underwent significant transformations in terms of appearance and size. At the beginning of the industrial productions, porcelain gres tiles were considered as just a technical material characterized by strong resistance to both abrasion and acid attack, almost lack of porosity, but aesthetically not very beautiful. Today thanks to new industrial production methods, both properties and beauty of these materials completely fit the market requests. In particular, the possibility to prepare slabs of large sizes is the new frontier of the building materials.
Beside these noteworthy architectural features, new surface properties have been introduced in the last generation of these materials. The present paper reports the research at the base of a new kind of fired tiles able to carry out a specific antibacterial and self-cleaning action and to reduce polluting molecules thanks to its new photocatalytic properties due to the surface presence of photoactive micro-TiO2
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