1,721,161 research outputs found
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
Diagnostics of Bearings in Rolling Stocks: Results of Long Lasting Tests for a Regional Train Locomotive
No full textThe application of Prognostics and Health Monitoring (PHM) concepts in rail vehicles is a rapidly growing field of research, and extensive efforts are being spent with the aim of improving the reliability and availability of railway systems and of substantially reducing maintenance costs by switching from time-based to event-driven maintenance policies. This paper is aimed at proving that effective PHM can be applied also on already existing rolling stocks. To do this, and focusing on bearings of the traction system, a prototype monitoring system, described in the paper, was developed and installed on a E464 locomotive. This regional train locomotive class, despite being recent since they were built between 1999 and 2015, is not equipped by any monitoring system for the bearings. The bearings have been monitored for about three years of service, during which the locomotive has undergone to a major maintenance and all the bearings of the traction system has been replaced. This allowed to examine them and to assess if damage indexes corresponded to actual faults. A huge amount of vibration data has been collected and it was possible to assess that the overall system cannot be considered as in stationary operation, neither when the train speed is constant nor when the same track is travelled. Many different techniques have been developed and tested with the aim of detecting bearing damages, considering that fault signals are heavily masked noise. The results are here described and it is shown that the introduced fault indexes are able to monitor the damage evolution in non-stationary conditions
Blade Modal Analysis by Means of Continuous Optical Fiber Sensors
No full textA new method for blade modal analysis is introduced in this paper by using continuous optical fiber sensors and optical backscatter reflectometer technology. The main advantage is that the sensor is few invasive and does not affect substantially system parameters. Moreover, the optical fiber sensor can be embedded in composite blades, for instance directly woven in carbon fiber fabric. This allows the sensor to be always installed and ready to use for continuous condition monitoring of the blade. Differently from classical sensors, which can be placed independently from the others, in this case, all the measurement points are placed on the same wire (the fiber itself), characterized by a finite length. Furthermore, due to the physical characteristics of the fiber, some constraints on how the fiber is placed, such as maximum fiber curvature, must be considered. Moreover, strain measurements are collected and precise positioning is required to reconstruct correctly the displacement modal shapes from the strains. In the literature, many optimal placement methods for sensors are proposed, but they are all referred to independent sensors. An optimal method for optical sensor placing on the blade for modal analysis is first introduced in the paper. Then, numerical and experimental tests performed on some blades are shown
Special Signal Processing Tools for the Experimental Data of Spiral Vibrations
No full textThe occurrence of spiral vibrations in large rotating machines is not a very common phenomenon. However, this kind of shaft vibration, usually caused by rubs between rotating and stationary parts, may give rise to a rather quick and considerable change of the vibration amplitudes. Some well-known methods can be used to study and simulate spiral vibrations, however, further unconventional techniques have been developed by the authors to analyse experimental vibration data of rotating machines that are affected by this phenomenon. The results provided by these innovative techniques can allow the models used by common investigation methods to be developed and optimized. Moreover, they can also be useful to conceive effective corrective actions that can eliminate spiral vibrations. In the paper, the results obtained by applying unconventional techniques to the analysis of stable and unstable spiral vibrations that affected the dynamic behaviour of a large rotating machine, on which brush seals were mounted, are shown and discussed
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