1,721,127 research outputs found
Pyramid wavefront sensors for astronomy and for the human eye
Full text linkWaveFront Sensors (WFSs) may be defined as the heart of an adaptive optics system since they analyze the radiation coming from reference sources and allow to quantify the distortion of a wavefront.
Among the varieties of existing WFSs, my PhD research thesis focuses especially on innovative optical systems taking advantage of the peculiarities of the Pyramid WFS.
In my PhD project I have designed, implemented, characterized or studied three different applications characterized by the fact that one or multiple pyramid WFSs play a major role. They extend from WATERFALL, an application for the human eye (8 mm), to a Very-Linear (and very sensitive) WFS (VL-WFS), part of a concept for a 40 meter telescope adaptive optics, passing through a very complex system featuring more than 100 degrees of freedom, to be mounted on 8.4 m x 2 LBT telescope (Ground-layer WFS for LINC-NIRVANA).
WATERFALL concerns the design and successful realization of a prototype for opthalmologic application for industrial commercialization to measure dioptric power of Intra-Ocular Lenses.
GWS for NIRVANA works includes the definition of tolerances to be met and the detailed description of its alignment, integration phase and successful verification, leading it toward its on-sky commissioning phase in the Pathfinder experiment.
The VL-WFS is in its very early phase, concepts and new ideas (mostly coming from our group) have to be organized in order to make a real proposal of a Global MCAO instrument for the E-ELT.
The projects briefly presented are all based on the same optical concepts and if the ophthalmology application might at first sight look unrelated to astronomy, it is, in fact, representing a simple SCAO system applied to an optical system which is the eye, proving how the interaction between different research field can lead to successful results
SHARK-NIR - Chroma scientific BB+NB filters characterization
No full textThis document presents the report of the tests and the analysis performed on the scientific filters BB + NB of Shark-NIR, realized by the company Chroma, to verify their compliance to the given specification
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
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