1,721,010 research outputs found
Enabling focusing around the corner in multiple scattering media
No full textWe report an alternative experimental setup to laterally focus light at an angle of 90 deg relative to turbid, multiple scattering media, using preprocessing wavefront shaping. We compare the measured image quality to one obtained in the usual configuration for focusing light through turbid media, where focusing occurs behind the scattering sample. We demonstrate that the depth of focus in the lateral configuration is of the same order of the usual transversal one because both setups are designed to operate in the deep Fresnel zone. This result shows that this novel, versatile lateral configuration allows for effectively focusing around corners through multiple scattering samples
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
Channel waveguide lasers and amplifiers in single-crystalline ytterbium-doped potassium double tungstates
Full text linkIn this work the technology of Gd3+ and Lu3+ co-doped KY(WO4)2:Yb3+ thin films grown onto pure KY(WO4)2 substrates by liquid phase epitaxy (LPE) is explored. The co-doping enables lattice matching of the grown layer with the substrate and enhances the refractive index difference between the grown layer and the undoped KY(WO4)2 substrate. This technology enabled the demonstration of waveguide lasers with tight pump and laser mode confinement, resulting in excellent slope efficiencies in Yb3+-doped planar and microstructured channel waveguide lasers of 82.3% and 72%, respectively. Fabrication of double tungstate microstructured channel waveguides with further enhanced refractive index contrast of 1.5×10-2 by completely interchanging the Y3+ component of the KY(WO4)2 host material with Gd3+, Lu3+, and Yb3+ doping allows for the demonstration of a laser with an output power of 418 mW at 1023 nm and slope efficiency of 71% versus launched pump power. In addition, in two other resonator configurations these channels showed broad tunability of the laser wavelength from 980 to 1045 nm as well as a low quantum defect of 0.7% when pumping at 973 nm and lasing at 980 nm, thereby minimizing heat dissipation in the device. Laser operation at 980 nm is achieved in an open cavity configuration, which allows for optimal extraction of the laser power, resulting in a total extracted emission of 650 mW. Moreover, Laser emission has been demonstrated by an on-chip resonator structure fabricated using a deep Bragg-reflector milled by a focused ion beam (FIB) through the complete waveguide structure, similar to the approach demonstrated in a semiconductor gain material. Micro-chip optically active devices, currently developed in the well-established semiconductor gain material platform, can be possibly being fabricated in the discussed rare earth ion doped material platform. This is highlighted by the last outcome of this project; demonstrating similar modal gain compared to state of the art semiconductor waveguide amplifiers of nearly 1000 dB/cm. To obtain this remarkable result the developed technology is used for the fabrication of nearly 50% Yb3+-doped channel waveguide structures. This result is beyond the common expectation, as rare earth ions are regarded as impurities providing low gain
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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