1,720,983 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
Analysis of debonding in bio-inspired interfaces obtained by additive manufacturing
Full text linkThe present work is focused on the analysis of fracture in adhesive bonded Double Cantilever Beam (DCB) specimens with 3D printed nylon substrates. The substrates were obtained using selective laser sintering of polyamide powder and embed sub-surface channels with circular and square cross-section. The proposed strategy allows to mimic the crack trapping effect already observed in a multitude of biological materials, that is originated by the spatial modulation of the driving force available for crack growth. Mechanical tests have shown that the channels induce load fluctuations in the global load-displacement response. A significant increase in the total dissipated energy was observed with respect to bulk samples, i.e. no channels. The observed fluctuations in the global response were associated to the sequential storage and sudden release of elastic energy. Indeed, the spatial modulation of the stiffness around the interfacial region ultimately affects the crack driving force
Improving performance of composite/metal T-joints by using corrugated aluminum stiffeners
No full textAnalysis of crack trapping in 3D printed bio-inspired structural interfaces
Full text linkSpecific features of biological materials, such as microstructure, heterogeneities or hybrid compositions, already inspired the fabrication of several architected materials. More recently, special emphasis has been placed on the development of damage tolerant interfaces by introducing tailored surface heterogeneities. However, thanks to the current developments in the area of additive manufacturing, the mating substrates can be now fashioned into complex shapes to confer the desired joint behavior. By taking inspiration from the base plate of the Balanus Amphitrite, we recently employed 3D printing to fabricate bio-inspired structural interfaces and adhesive bonded Double Cantilever Beam (DCB) fracture specimens. The results of DCB tests have shown a remarkable increase in the total dissipated energy with respect to baseline samples. In this work we supplement our previous study by performing finite element simulations in order to ascertain the variation of the driving force as a function of crack advance. The obtained results, which are analyzed in conjunction with high resolution imaging of the crack propagation process, allow to further elucidate the mechanics of debonding. It is shown that the sub-surface channels can modulate the driving force available for crack growth, introducing a crack trapping ability which depends on the specific geometry of the interfacial region
Mechanical Characterization of Metal–Polymer Joints Fabricated via Thermal Direct Bonding Technique †
Full text linkCrack propagation in adhesive bonded 3D printed polyamide: Surface versus bulk patterning of the adherends
No full textThe confined build space of 3D printers often necessitates breaking down larger objects into sub-components for efficient printing. Addressing this challenge, related existing research emphasizes the growing adoption of structural adhesives as a key method for joining 3D printed components. In this context, the present study combines finite element modeling, design exploration, and additive manufacturing, to ascertain the role of the adherends’ architecture on the mechanics of crack growth in adhesive bonded 3D printed materials. Finite element simulations and experiments are carried out using Double Cantilever Beam (DCB) specimens comprising epoxy-bonded selective laser sintered polyamide (PA). In particular, the study includes adherends that feature either sub-surface hollow channels of various shapes (bulk patterns) or sinusoidal interfaces with different aspect ratios (surface patterns). The objective is to demonstrate how the proposed patterning strategies not only promote crack shielding and delayed growth but also unlock energy-absorbing processes, such as interfacial void growth and buckling, that are absent in the control joint (i.e., no patterns). Therefore, customizing the architecture of the adjoined layers ultimately results in toughening and enhanced damage tolerance in adhesive joints that comprise 3D printed materials
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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