1,720,962 research outputs found

    Controlling the impact of Modal Noise on Harmonic and Intermodulation distortions in Radio over Multimode Fiber links

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    Important and at first glance unexpected influences of Modal Noise on Harmonic and Intermodulation distortions in Radio over Multimode Fiber links for In-Building Wireless Coverage are described for the first time. Design options allowing to control such impact are illustrated

    Reducing modal noise in short-range radio over multimode fibre links

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    Reducing gain fluctuations in Short Range Radio over Multimode Fiber Links requires Central Launch. Furthermore, the quality of today's optical connectors gives importance to the combined effect of finite detecting area and Laser frequency chirp. © 2010 Optical Society of America

    Reducing modal noise in short-range radio over multimode fibre links

    No full text
    Reducing gain fluctuations in Short Range Radio over Multimode Fiber Links requires Central Launch. Furthermore, the quality of today's optical connectors gives importance to the combined effect of finite detecting area and Laser frequency chirp

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

    Comeback of Fabry Perot RoMMF Transmitters for improved LTE signals distribution

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    A radio over multimode fiber (RoMMF) for short-range distribution of wireless signals with a very high performance to cost ratio is demonstrated. Thanks to the quality of today Fabry-Perot lasers, the adopted transmitter results from the conscious reuse of a solution initially conceived for single mode fiber transmission. The worst-case spurious free dynamic range of the proposed system exceeds 105 dBHz2/3 up to 525 m of OM2 multimode fiber. Experimental and theoretical results are reported showing that this scheme outperforms a RoMMF system employing either a distributed feed-back or a Fabry-Perot laser diode realized with recent-past technologies. With the proposed system, Long Term Evolution signal transmission is achieved with high quality in terms of Adjacent Channel Power Ratio and Error Vector Magnitude

    Variations on the Author

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    “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

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    We 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

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    We 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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