1,720,960 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Characterization of Biopolymers Porous Systems Using X-ray Tomography
No full textTato diplomová práce se zabývá 3D tiskem biomateriálů na bázi želatiny, síťované pomocí Schiffových bází. Připravené materiálové sady se liší typem želatiny (hovězí a králičí), poměrem želatiny a oxidovaného dextranu (1 ku 1, 2 ku 1, 3 ku 1), počtem natisknutých vrstev (1, 3, 5) a typem aktivačního činidla (NH3, TEA). Cílem této práce bylo posouzení vlivu přípravy materiálu a tiskových podmínek na výslednou porozitu vzorků (počet, velikost, objem pórů) pomocí metody SEM a CT. Tiskový materiál na bázi želatiny představuje slibný materiál pro přípravu matrice pro implementaci kmenových buněk in vivo. Její velkou nevýhodou je rozpustnost ve vodě a slabá mechanická stabilita, znemožňující její použití v 3D tisku, jehož řešení spočívá v dodatečné síťování. Proces síťování však v mnoha případech může vést k nárůstu cytotoxicity. Tento problém lze vyřešit síťováním pomocí Schiffových bází. Výsledky této diplomové práce potvrdily, že celková porozita materiálů na bázi želatiny, se liší v závislosti na původu želatiny, počtu tiskových vrstev, použitém poměru želatiny k oxidovanému dextranu a typu aktivačního činidla. Připravený materiál, tak představuje velký potenciál v přípravě bioinku, především díky jeho biokompatibilitě, nízké toxicitě, i možnosti jeho použití při 3D tisku různých struktur.This diploma thesis deals with 3D printing of biomaterials based on gelatin, crosslinked using Schiff bases. The prepared material differs in type of gelatin (bovine and rabbit), ratio between gelatin and oxidized dextran (1 to 1, 2 to 1, 3 to 1), number of printed layers (1, 3, 5) and type of activating agent (NH3, TEA). The aim of this work was to assess the influence of material preparation and printing conditions on the resulting porosity of samples (number, size, total volume of pores) using SEM (scanning electron microscopy) and CT (computed tomography). The gelatin-based printing material is a promising material matrix for implementation of stem cells in vivo. A great disadvantage is its solubility in water and poor mechanical stability, which makes it impossible to be used in 3D printing. The solution to this problem lies in additional cross-linking. However, the cross-linking process can in many cases lead to an increase of cytotoxicity. This situation can be solved by cross-linking using Schiff bases. The results of this thesis confirmed, that the overall porosity of gelatin-based materials depends on the source of gelatin, the number of printing layers, the ratio of gelatin and oxidized dextran and the type of activating agent. Prepared material shows a great potential in preparation of bioink, mainly due to its biocompatibility, low toxicity, and the possibility to use it in 3D printing of various structures.Ústav fyziky a mater. inženýrstv
Characterization of 3D Printed Polymer Structures by X-ray Tomography
No full textByly studovány možnosti 3D tisku polymerních mřížek s otvory o rozměrech v řádech stovek mikrometrů. Studované vzorky byly připravovány pomocí FDM a SLA metody 3D tisku. Vytvořené mřížky byly charakterizovány pomocí rentgenové tomografie a skenovací elektronové mikroskopie. Reprodukovatelnost tištěného modelu pomocí 3D tisku byla hodnocena v závislosti na použitém materiálu, tloušťce tisknuté vrstvy a vlastních rozmě-rech mřížky. Experimentální výsledky ukazují limity a možnosti použitých tiskových zaří-zení při tisku daných typů materiálů. V případě FDM metody lze dosáhnout nejlepších výsledků při co nejmenší vzájemné vzdálenosti vytlačovaného materiálu. U metody SLA je nezbytné zvolit co nejmenší tloušťku jednotlivých tištěných struktur.They have been studied options for 3D printing of polymer grids with sizes of holes in hundreds of micrometres. The studied samples were being prepared using FDM and SLA of 3D printing method. Created grids were characterized using roentgen tomography and scanning electron microscopy. Reproducibility of printed model using 3D printing, were evaluated according to used material, the thickness of printed layer and the actual grid di-mension. The experimental results show the limits and possibilities of the used printing devices according to types of used materials. In the case of FDM method the best results can be achieved at the lowest possible distance of the extruded material. For the SLA method, it is necessary to choose the lowest possible thickness of the individual printed structures.Ústav fyziky a mater. inženýrstv
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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