1,720,968 research outputs found
Calculation of coupling loss factors using a hybrid finite element/wave and finite element approach
No full textThe vibration of built-up structures at higher frequencies can be analysed using energy based methods such as the Statistical Energy Analysis (SEA). Central to SEA is the calculation of the coupling loss factors (CLFs) between the subsystems. This can be difficult, for example when complex joints connect wave-bearing substructures of complicated constructions (laminates, truss cored or sandwiched panels, etc.). In this paper, we present a hybrid finite element/ wave and finite element approach for predicting these CLFs. Each substructure is modelled using the wave and finite element (WFE) method where a small segment of the structure is modelled using standard finite element (FE) techniques and then periodic structure theory is used to predict the wave characteristics of the substructure. The propagating waves in the substructure are treated as SEA subsystems. The joint is modelled using standard FEs, and the joint FE model is coupled with the WFE models of the substructures to yield the scattering properties of the joint. These can then be used to predict the diffuse field transmission efficiency and CLFs between the various subsystems. The strength of the approach is two-fold. First, the substructures and joints can be arbitrarily complicated. Second, the full power of existing FE libraries/packages can be used to obtain the WFE models of the substructures and the FE model of the joint. Numerical examples are presented to illustrate the approach
Modelling the Dynamics of Laminated Panels Using a Wave and Finite Element Method
No full textThe use of laminated panels is increasing because they are stiff, light and offer the engineer flexibility in design. Constructions include composite laminates with various stacking sequences, foam cores, viscoelastic layers etc. The generality and complexity of construction raises issues regarding modelling their dynamics and optimising their design. In this paper a wave and finite element (WFE) method for modelling the dynamic behaviour of plane and axisymmetric laminated structures is described. A small segment of the structure is modelled using conventional finite element (FE) methods, usually using a commercial package. This typically involves a stack of solid elements meshed through the thickness, allowing the shear distribution, in particular in soft layers, to be correctly represented. The mass and stiffness matrices are found, periodicity conditions applied, and an eigenvalue problem solved to find the dispersion relations and hence the characteristics of wave propagation, attenuation and damping. The frequency dependence of viscoelastic material properties and pre-stress can be taken into account straightforwardly. A hybrid FE/WFE approach to determining transmission characteristics of joints is described. Numerical examples are presented, including
anisotropic, plane and cylindrical foam-cored laminate sandwich constructions with pre-stress. The method is simple in application, provides accurate results at low computational cost and is a valuable tool for evaluating the vibroacoustic behaviour of multi-layer panels and optimising their design
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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