1,720,954 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 Mechanical Properties of Recycled Polyethylene Terephthalate
No full textDiplomová práce se zabývá problematikou recyklace polyethylentereftalátu, většina lidí ho zná pod zkratkou PET. Tato práce vznikla z důvodu nátlaku společnosti na cirkulární ekonomiku, která je příčinou zvýšeného podílu recyklovaného materiálu v oběhu. V následujících letech nastane doba, kdy některé výrobky budou mít za sebou více recyklačních cyklů a z důvodu udržení stejné kvality výrobků je nutné znát charakteristiku a chování těchto materiálů s více recyklačními cykly. Experimentální část začala přípravou zkušebních těles z panenského polyethylentereftalátu na vstřikovacím stroji. Následně byly hotové výrobky pomlety na nožovém mlýnu zpátky na granulát a tento regranulát byl opět vystříknut na stroji. Tento proces se opakoval několikrát a výsledkem byly vzorky s různým recyklačním cyklem z předem definovaného panenského materiálu. Poté jsou zkoumány mechanické vlastnosti těchto různě recyklovaných vzorků a také jsou provedeny další charakterizace. Výsledkem tohoto experimentu je, že mechanické vlastnosti PET se rapidně mění s recyklačním cyklem. Tyto změny jsou dané především stupněm krystalinity, protože při mechanické recyklaci dochází k lámání vazeb, polymeru se zkracují řetězce a ty se dokážou rychleji uspořádat do krystalických struktur.The thesis deals with the recycling of polyethylene terephthalate, most people know it by its acronym PET. This work is due to society's pressure on the circular economy, which is responsible for the increased proportion of recycled material in circulation. There will be a time in the coming years when some products will have had more recycling cycles and in order to maintain the same product quality it is necessary to know the characteristics and behaviour of these materials with more recycling cycles. The experimental part began by preparing test bodies from virgin polyethylene terephthalate on an injection molding machine. Subsequently, the finished products were ground on the knife mill back onto the granulate and this regranulate was sprayed again on the machine. This process was repeated several times, resulting in samples with different recycling cycles of pre-defined virgin material. The mechanical properties of these differently recycled samples are then examined and further characterisations are carried out. As a result of this experiment, the mechanical properties of PET change rapidly with the recycling cycle. These changes are mainly due to the degree of crystallinity, as mechanical recycling breaks bonds, polymer shortens chains and they can be arranged more quickly into crystalline 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
Preparation and Characterization of 3D Printed Structures Based on Synthetic Polymers
No full textTato práce je zaměřena na studium a optimalizaci tiskových parametrů pro 3D tisk polykaprolaktonu. Zvolenými tiskovými metodami byla termoplastická extruze a pneumatická mikroextruze. Sledovanými tiskovými parametry byla teplota tiskové hlavy, vytlačovací tlak, průměr trysky či jehly, rychlost tisku a teplota tiskové podložky. Dále byla optimalizována směs polykaprolaktonu s dobrými rozpouštědly případně s přídavkem špatného rozpouštědla za účelem tvorby strukturovaných 3D tištěných objektů. Tištěné objekty v podobě mřížek byly sledovány pomocí elektronové mikroskopie a kontaktní profilometrie. Z výsledků vyplývá, že zvolením vhodné třísložkové směsi polymeru, dobrého a špatného rozpouštědla lze poměrně jednoduše a v jednom kroku připravit strukturované objekty. S ohledem na možné využití těchto struktur pro budoucí studium buněčných interakcí byla pomocí infračervené spektroskopie ověřena čistota výtisku, jenž obsahuje pouze polykaprolakton bez rozpouštědel.This work is focused on the study and optimization of printing parameters for 3D printing of polycaprolactone. The selected printing methods were thermoplastic extrusion and pneumatic microextrusion. The monitored printing parameters were the print head temperature, the extrusion pressure, the diameter of the nozzle or needle, the printing speed and the temperature of the print bed. Furthermore, the mixture of polycaprolactone with good solvents or with the addition of poor solvent was optimized in order to create structured 3D printed objects. Printed objects in the form of grids were monitored by electron microscopy and contact profilometry. The results show that by selecting a suitable three-component mixture of polymer, good and bad solvent, structured objects can be prepared relatively easily in one step. With regard to the possible use of these structures for the future study of cell interactions, the purity of the printed product, which contains only solvent-free polycaprolactone, was verified by infrared spectroscopy.Ústav fyziky a mater. inženýrstv
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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