1,720,959 research outputs found
Self-assembled periodic microfluidic structures in a hollow optical fiber
No full textWe report novel periodic microfludic structures in a hollow optical fiber (HOF) filled with water and air. The structures within the HOF were fabricated using a flame brushing technique and its optical characteristics are presente
Self-Assembled Femtoliter-Scale Structures in a Hollow Optical Fiber for Optofluidic Applications
No full textWe propose self-assembled femtoliter-fluid formation depending on temperature in a hollow optical fiber (HOF) by the unsophisticated flame brushing technology. Three kind of structures are generated, also we see the optical property
Acousto-optic control of speckle contrast in multimode fibers with a cylindrical piezoelectric transducer oscillating in the radial direction
No full textWe report efficient acousto-optic control of speckle contrast at the output of multimode fibers (MMFs) using a cylindrical piezoelectric transducer (PZT) vibrating in the radial direction. With appropriate packaging of an MMF around the PZT, periodic stretching and subsequent intensity modulation were achieved over the wound fiber to result in time-averaged smoothing of the output within a short time. It was experimentally confirmed that light passed through the vibrating PZT-fiber assembly maintains the virtually partial coherence irrespective of the guide length and power splitting. Real-time vibration-off/on movies were presented, and their single-frame excerpts were analyzed
Compact all-fiber Bessel beam generator based on hollow optical fiber combined with a hybrid polymer fiber lens
No full textWe report a compact all-fiber Bessel beam generator using hollow optical fiber (HOF) and coreless silica fiber based on a self-assembled polymer lens. A nearly diffraction-free Bessel beam pattern was observed with its focused beam diameter of 20 µm maintained over a propagation distance of 550 µm. The generated Bessel beams were experimentally tested under various structural parameters such as the diameters of the HOF and operating wavelengths. A beam propagation method was applied to simulate the proposed device, which shows good agreement with the experimental observations
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
Beam shaping technology based on optical fiber for applications in laser, optical tweezer, and free space interconnects
No full textVarious techniques to modify the phase front of the light wave out of an optical fiber facet are reported for beam shaping devices. The principles of beam shaping in the devices and their applications in lasers, optical tweezer, and photonic devices 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
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
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