1,722,069 research outputs found
The impact of face image compression in future generation electronic identity documents
No full textElectronic identity documents are spreading worldwide and the digital identification procedures relying on them are increasingly important for national and international security. In this paper, we study the impact of lossy compression on face images within the electronic identity documents domain. The study is conducted following the enrolment process in accordance with the current regulations and their recent updates that push the compression ratio further. Several experiments were carried out using different datasets, each one reflecting a specific enrolment setting as suggested by ISO and ICAO incoming regulations. The results are controversial. Even though the commercial tool we used for our experiments reported only negligible variations after image compression, the well-known open-source tool we adopted showed a considerable worsening. Image size limited to the current specifications could waste the benefits derived from the enhancements in the enrolment process concerning the original photo size and the scanning/acquisition quality. As a cautionary remark, we thus believe it would be preferable to update the enrolment guidelines, specifying to increase the space reserved for the facial image
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
Piezoelectric displacement mapping of compliant surfaces by constant-excitation frequency-modulation piezoresponse force microscopy
No full textA simple experimental method for piezoresponse force microscopy (PFM) measurements for reliable evaluation of piezoelectric surface displacements even on compliant surfaces is proposed based on atomic force microscopy (AFM) operated in frequency-modulation (FM) dynamic mode with constant excitation (CE), by using non-contact mode cantilevers. Surface displacement by piezoelectric effect after application of an electric potential to the conductive AFM probe translates into a likewise variation of the probe oscillation amplitude, while the related electrostatic forces mainly affect the oscillator resonant frequency, and cantilever bending is limited due to their high stiffness. Our non-contact CE-FM-PFM method is shown to reduce electrostatic force contributions as compared to contact-PFM modes. Converse piezoelectric effect mapping is demonstrated on poly(vinylidenefluoride) nanofibers obtained by electrospinning
Use of organic additives as binders in raw mixtures for ceramic tiles
No full textThe aim of this work is the study of the role played by organic additives used as binders in raw mixtures for ceramic tiles. Such binders are extensively used for the production of advanced ceramic materials. In traditional ceramics, they can, in principle, allow for a drastic education of the clay fraction and consequently a very positive effect on the colour of the ceramic body without affecting its peculiar physical properties. Polyvinyl alcohol (PVA) was added in proportions of less than 0.5 wt% to different typical raw ceramic mixtures in which the weight fraction of clay minerals was reduced of about 50 wt%. In each case, it was possible to obtain very good mechanical properties of the green bodies. Clay minerals are the component of the mixture with the highest price and the highest content of iron and titanium (known to have negative effects on the whiteness of the ceramic body). Decreasing the amount of clay minerals makes possible to produce ceramic bodies with the same colour, using less quality (i.e. less expensive) raw materials. This can also lead to reconsider the use of several raw materials present on the national territory. Furthermore, superwhite ceramic bodies can easily be obtained even without the introduction of very expensive components such as zircon and alumina. Possible drawbacks appear to be not severe as the milling times are increased of less than 3% (in laboratory), and additional costs due to the organic additive are overwhelmed by the savings due to the choice of less expensive raw materials and the reduction of the clay fraction (up to 20%)
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