1,720,988 research outputs found
Robust statistical methods for the GPS network analisysis
No full textThe possible presence of outliers in observations requires a refined statistical analysis for the traditional, as wella as GPS networks. After a least square adjustment is performed, tradiional methods essentially consist in a standardised residual analysis. Tha so-called "preliminary diagnostic procedures" allow the identification of outliers and their removal. The "Baarda data snnoping", the "t test" and the "Danish method" are well known statistical methods commonly applied in Geodesy. In the last few years a class of alternative estimation strategies has been proposed, known as robust methods (Huber, Hampel, Rousseeuw). A major advantage in the use of such methods is that the parameters obtained are only slightly influenced by outliers in the observations. Two different applications of robust estimation are discussed in the paper; their application to a simulated GPS network and to a real GPS net for deformation control is presented
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
A simple and industrially scalable method for making a PANI-modified cellulose touch sensor.
No full textA simple and industrially scalable method for making a PANI-modified cellulose touch sensor.
Ragazzini a, I. Gualandi a, *, S. Selli b, C. Polizzi a, M.C. Cassani a, D. Nanni a, F. Gambassi a, F. Tarterini a, D. Tonelli a, E. Scavetta a, B. Ballarin a, *
a Department of Industrial Chemistry “Toso Montanari”, Bologna University, Viale Risorgimento 4, I-40136, Bologna, Italy; b Cromatos s.r.l., via G. Cardano, 6B/C/D, 47122, Forlì, Italy
Nowadays, alternatives to the traditional electronics that should be low cost, degradable, compostable and made from environmentally nontoxic substances are of great interest in research. As candidate, we propose bare fibers of cellulose made conductive by an in situ oxidative polymerization of aniline. The resulting composite fibers were emplojed to fabricate electroactive sheets using a pilot plant of a typical paper industry. The resistivity of the obtained sheets is 14 ± 1 Ω sq-1, a value around 1000 times lower than those reported in literature. The higher electronic performances of the sheets were demonstrated by assembling a capacitive touch sensor device with optimized geometry. The touch sensor shows an increase of 3–4 % of the starting electric capacity after compression and a fast response time of 52 ms. To our knowledge this is the first time that a device is prepared in this way and therefore, the herein presented results can bring a significant improvement in the development of low-cost, green and high-tech electronic devices 1.
[1] Ragazzini, I. et al. A simple and industrially scalable method for making a PANI-modified cellulose touch sensor. Carbohydr. Polym. (2020) doi: 10.1016/j.carbpol.2020.117304
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
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