1,720,967 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
Exploring the anionic sulfinyl precursor route towards tailor-made PPV block copolymer materials
No full textTailor-made poly(p-phenylene vinylene)s (PPVs) are presented in this thesis with their ability to be polymerized in an anionic fashion starting from sulfinyl premonomers. For this sulfinyl precursor route, it is shown that with the use of lithium hexamethyldisilazide (LHMDS) as the base and THF as the solvent, the polymerization mechanism can be shifted towards a pure anionic pathway leading towards well-defined polymers. Further it is shown that this anionic mechanism can be applied to plain-PPV as well as different substituted premonomers (symmetrical and (ester-functionalized) unsymmetrical alkyloxyand cyano side groups incorporated on the aromatic core). The most studied polymer in this thesis is the symmetrically substituted poly[2,5-bis(2- ethylhexyloxy)p-phenylene vinylene] (BEH-PPV). With the use of anionic initiators, with a structure similar to the premonomer structure, efficient control is reached over molecular weight (between 15500 and 3000 g·mol-1 for conjugated material) and PDI (1.5 – 1.1). The high efficiency of incorporation of these units with different functionalities, is proven using electrospray ionization – mass spectrometry (ESI–MS). Because of the linear correlation that is found between molecular weight versus amount of initiator used, this high initiator efficiency is assumed to translate to all polymers synthesized using this method, underpinning the living nature of the polymerization. The ω-chain end cannot be controlled as confirmed via either ESI–MS or using a 13C-labeled end-capper. In further experiments the addition mode of the initiator to the reaction mixture and reaction temperature and time are explored. These experiments reveal that the polymerization reaction is very fast, even at reaction time “zero” and reaction temperature -78 °C high molecular weight (5900 g·mol-1) is reached for a polymerization reaction with addition of 0.1 eq of initiator, and thus no kinetics are studied for this system so far. In a last attempt to enhance the control over the anionic pathway, a specialized anionic polymerization setup – in collaboration with the University of Groningen – is used to perform the polymerization reactions. As is shown in this work, the obtained results are in good agreement with the results gained using the regular Schlenk lines (vacuum/N2). ..
Exploring the anionic sulfinyl precursor route towards tailor-made PPV block copolymer materials
No full textTailor-made poly(p-phenylene vinylene)s (PPVs) are presented in this thesis with their ability to be polymerized in an anionic fashion starting from sulfinyl premonomers. For this sulfinyl precursor route, it is shown that with the use of lithium hexamethyldisilazide (LHMDS) as the base and THF as the solvent, the polymerization mechanism can be shifted towards a pure anionic pathway leading towards well-defined polymers. Further it is shown that this anionic mechanism can be applied to plain-PPV as well as different substituted premonomers (symmetrical and (ester-functionalized) unsymmetrical alkyloxyand cyano side groups incorporated on the aromatic core). The most studied polymer in this thesis is the symmetrically substituted poly[2,5-bis(2- ethylhexyloxy)p-phenylene vinylene] (BEH-PPV). With the use of anionic initiators, with a structure similar to the premonomer structure, efficient control is reached over molecular weight (between 15500 and 3000 g·mol-1 for conjugated material) and PDI (1.5 – 1.1). The high efficiency of incorporation of these units with different functionalities, is proven using electrospray ionization – mass spectrometry (ESI–MS). Because of the linear correlation that is found between molecular weight versus amount of initiator used, this high initiator efficiency is assumed to translate to all polymers synthesized using this method, underpinning the living nature of the polymerization. The ω-chain end cannot be controlled as confirmed via either ESI–MS or using a 13C-labeled end-capper. In further experiments the addition mode of the initiator to the reaction mixture and reaction temperature and time are explored. These experiments reveal that the polymerization reaction is very fast, even at reaction time “zero” and reaction temperature -78 °C high molecular weight (5900 g·mol-1) is reached for a polymerization reaction with addition of 0.1 eq of initiator, and thus no kinetics are studied for this system so far. In a last attempt to enhance the control over the anionic pathway, a specialized anionic polymerization setup – in collaboration with the University of Groningen – is used to perform the polymerization reactions. As is shown in this work, the obtained results are in good agreement with the results gained using the regular Schlenk lines (vacuum/N2). ..
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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