1,721,011 research outputs found
Directional edge enhancement using a liquid-crystal display
No full textWe present a method for orientation-selective enhancement of the first derivatives of an image. The proposed method is based on the polarization properties of the twisted-nematic liquid-crystal displays (LCDs). LCDs are manufactured to work between a polarizer-analyzer pair, and for a given incident polarization direction, the image contrast will depend on the analyzer orientation. In particular, two analyzer orientations of interest could be identified for the proposed experiments: one that reproduces the image displayed on the LCD, and the other one (orthogonal to the former) that gives a negative (contrast reversed) replica of the original image. By placing a beamsplitter after the LCD, two images are spatially separated, analyzed by linear polarizers in perpendicular directions, and then slightly displaced. When the original image and its displaced (contrast reverted) replica are imagined together across a plane, one obtains a resultant image with enhanced first derivatives along a specific direction. Unlike the usual Fourier (coherent) image processing, the technique proposed here works with incoherent illumination. Validation experiments are presented. © 2010 Elsevier B.V. All rights reserved
Color deflectometry for phase retrieval using phase-shifting methods
No full textIn this paper, we propose a technique based on a color fringe pattern used on deflectometry experiment. The advantages of using color fringe patterns together with phase shifting techniques on deflectometry experiment are presented. An experimental wavefront reconstruction of a progressive lens shows the accuracy and simplicity of these techniques used to process the deflection measurements. � 2014 Elsevier Ltd. All rights reserved
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
Spectroscopic measurement of ignition parameters in forest Fuel
No full textFuel Moisture Content (FMC) and leaf biochemical compounds are parameters used to determine forest ignition and can be obtained by the use of different methods, included optical and chemical techniques. Chemical techniques require approximately 20 hours to determine forest fuel chemical compounds and FMC. In contrast, optical techniques need a few minutes to know the FMC. However, with this is not possible to determine the chemical compounds without a previous treatment. PROSPECT is a radiative transfer model technique to describe reflectance and transmittance of leaves. Using visual and near infrared (Vis-NIR) spectroscopy, the specific absorption coefficient of leaf extract is obtained. This is used as a parameter for invert PROSPECT model and quantify resins, oils and waxes which constitute forest fuel. This research will give the basis for remote Vis-NIR spectroscopy using unmanned aerial vehicles (UAVs) for a dynamical ignition parameters acquisition. © 2014 SPIE
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
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
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