1,720,961 research outputs found
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
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
Improved resolution and signal-to-noise ratio performance of a confocal fluorescence microscope
Get PDFA culmination of theory, techniques and devices stemming from a wide variety of sources and disciplines, optical microscopy presents vast possibilities for visualisation of small structures. One of the most fundamental yet significant optical microscopy techniques is Confocal Fluorescence Microscopy (CFM). CFM is studied here by analysing its performance with respect to the two most important metrics - Signal-to-noise ratio and 3D optical resolution. Several authors have commented on the inherent inefficiency of imaging systems such as CFM to utilise the available light when providing resolution beyond the well-known diffraction limit, primarily due to the precise mechanisms that help realise the resolution gain in the first place. In CFM, the detection pinhole is the key mechanism that helps realise up to 1.4 times resolution improvement over conventional wide-field microscopy techniques by trading off SNR.
First, an investigation of the inherent SNR-resolution trade-off in a CFM system is studied; the impact of the detection pinhole geometry on the performance of a CFM is examined by means of an effective trade-off curve. Using alternative pinhole geometries in conjunction with new detection schemes, it is next shown how performance gains are realised in both the lateral and axial directions.
Examined next is a recently developed detection scheme called subtractive imaging; wherein a special annular pinhole is used to divide the confocal point spread function signal into two detectors. By using fast point detectors in place of CCD arrays, it is shown how using numerical optimisation yields an optimum “differential pinhole” to achieve considerable 3D resolution gains over conventional (circular pinhole based) CFM systems. By examining the trade-off curves it is also shown that the proposed design is able to offer simultaneous and maximum performance gains up to a considerably high SNR in comparison to conventional (circular pinhole) based CFM systems.
Lastly, the work will propose the use of a deconvolution technique and an alternative detection scheme to demonstrate substantially higher improvements in the quality of images acquired by a CFM system. Image reconstruction is a tried and tested image post processing strategy to realise super resolution. An image reconstruction technique, based on an expectation maximisation maximum likelihood (EM-ML) algorithm is used in conjunction with array detectors to demonstrate enhanced resolution and noise performance of a CFM system. The point scan method used here renders the algorithm slow with long run times. To mitigate this, structured illumination is used to show how similar resolution gains in the array detector based CFM systems could be realised but in a much shorter time
Improved resolution and signal-to-noise ratio performance of a confocal fluorescence microscope
Get PDFA culmination of theory, techniques and devices stemming from a wide variety of sources and disciplines, optical microscopy presents vast possibilities for visualisation of small structures. One of the most fundamental yet significant optical microscopy techniques is Confocal Fluorescence Microscopy (CFM). CFM is studied here by analysing its performance with respect to the two most important metrics - Signal-to-noise ratio and 3D optical resolution. Several authors have commented on the inherent inefficiency of imaging systems such as CFM to utilise the available light when providing resolution beyond the well-known diffraction limit, primarily due to the precise mechanisms that help realise the resolution gain in the first place. In CFM, the detection pinhole is the key mechanism that helps realise up to 1.4 times resolution improvement over conventional wide-field microscopy techniques by trading off SNR.
First, an investigation of the inherent SNR-resolution trade-off in a CFM system is studied; the impact of the detection pinhole geometry on the performance of a CFM is examined by means of an effective trade-off curve. Using alternative pinhole geometries in conjunction with new detection schemes, it is next shown how performance gains are realised in both the lateral and axial directions.
Examined next is a recently developed detection scheme called subtractive imaging; wherein a special annular pinhole is used to divide the confocal point spread function signal into two detectors. By using fast point detectors in place of CCD arrays, it is shown how using numerical optimisation yields an optimum “differential pinhole” to achieve considerable 3D resolution gains over conventional (circular pinhole based) CFM systems. By examining the trade-off curves it is also shown that the proposed design is able to offer simultaneous and maximum performance gains up to a considerably high SNR in comparison to conventional (circular pinhole) based CFM systems.
Lastly, the work will propose the use of a deconvolution technique and an alternative detection scheme to demonstrate substantially higher improvements in the quality of images acquired by a CFM system. Image reconstruction is a tried and tested image post processing strategy to realise super resolution. An image reconstruction technique, based on an expectation maximisation maximum likelihood (EM-ML) algorithm is used in conjunction with array detectors to demonstrate enhanced resolution and noise performance of a CFM system. The point scan method used here renders the algorithm slow with long run times. To mitigate this, structured illumination is used to show how similar resolution gains in the array detector based CFM systems could be realised but in a much shorter time
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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