1,721,235 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
Modelling of Cantilever-Based Flow Energy Harvesters Featuring C-Shaped Vibration Inducers: The Role of the Fluid/Beam Interaction
No full textEnergy Harvesters (FEHs), equipped with piezoelectric active layers, are designed
to extract energy from non-pulsating flows. FEHs featuring cantilevers with tip-mounted Vibration
Inducers (VIs) are designed to develop a galloping motion. In this paper, we present the modelling
of a recently introduced VI shape, featuring semitubular-shaped winglets, which do not produce
a wake interacting with the cantilever. Such peculiarity allows (i) to exploit the contribution of the
wake to the formation of the lift, therefore opening to a more compact design; (ii) its performance to
be analyzed by means of simple two-dimensional Computational Fluid Dynamics (CFD) simulations.
By comparison with experimental data, we show that the minimal framework for the modelling of
such new class of VIs needs to account for both the direct action of the fluid onto the cantilever and
the drag on the VI, which are usually negligible for other VI shapes
Mode Matching Analysis of Waveguide Components Exploiting the Variational Meshless Method
No full textThis letter presents the analysis of waveguide components comprising a cascade of step junctions by mode matching in conjunction with the variational meshless method (VMM). In particular, a large number of modal fields of the waveguides are calculated very efficiently by the VMM. Moreover, the collocation points are randomly distributed in each waveguide cross section, and the coupling coefficients are obtained regardless of their mutual distribution. The presented technique is validated through the analysis of two junctions reported in the literature and by comparison with an finite element method (FEM) full-wave software
Enhancing flow induced vibrations of a thin piezoelectric cantilever: Experimental analysis
No full textExploiting Symmetries in the Variational Meshless Method for 3-D Inhomogeneous Cavities
No full textThe variational meshless method (VMM) is a novel numerical algorithm that combines the intrinsic advantages of the meshless method based on the use of radial basis functions (RBFs) with the reliability of the variational formulation of electromagnetic boundary problems. It has been originally proposed and demonstrated in the analysis of 2-D structures, both homogeneous and inhomogeneous, aiming at the determination of the mode spectrum and the dispersion diagram. In this article, the VMM is extended to the calculation of the resonant modes of 3-D inhomogeneous cavities. The full theory is presented with implementation details. Moreover, the exploitation of symmetries is also discussed, which significantly speedup the method. Some examples are reported, and the results of the VMM are compared against either analytical values (when available) or commercial numerical codes based on the finite element method (FEM). In all cases, the VMM provides a large number of resonant modes with a limited number of unknowns, exhibiting high accuracy in short computing time
A new dynamic masking technique for time resolved PIV analysis: A new freeware raycasting tool combined with fluorescent coating to allow for object visibility
No full textAbstract: Time resolved PIV encompassing moving and/or deformable objects interfering with the light source requires the employment of dynamic masking (DM). A few DM techniques have been recently developed, mainly in microfluidics and multiphase flows fields. Most of them require ad-hoc design of the experimental setup, and may spoil the accuracy of the resulting PIV analysis. A new DM technique is here presented which envisages, along with a dedicated masking algorithm, the employment of fluorescent coating to allow for accurate tracking of the object. We show results from measurements obtained through a validated PIV setup demonstrating the need to include a DM step even for objects featuring limited displacements. We compare the proposed algorithm with both a no-masking and a static masking solution. In the framework of developing low cost, flexible and accurate PIV setups, the proposed algorithm is made available through a freeware application able to generate masks to be used by an existing, freeware PIV analysis package. Graphic abstract: [Figure not available: see fulltext.
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