1,721,231 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
Prosthetic rehabilitation of hyperbolic neck transmucosal implant using a digital workflow
No full textOBJECTIVESNew approaches for implant placement and new devices for prosthetic rehabilitation techniques are being developed to simplify both surgical and prosthetic phases and to obtain a predictable outcome.The purpose of this clinical case is to describe the advantages and limitations of a prosthetic digital workflow in presence of a single-tooth implant rehabilitation in the esthetic zone (anterior maxilla) using two-piece implant.MATERIALS AND METHODSA patient with a compromised upper right incisor, characterized by severe mobility, root resorption and chronic periapical lesion, underwent an atraumatic tooth extraction. Due to the absence of acute infection, immediate implant placement was scheduled.A two-piece implant was placed with the hyperbolic neck exposed approx. 1 mm above tissue levels (transmucosal placement). A Maryland Bridge restoration was designed before surgery through the acquisition of digital models using a digital intraoral scanner. The Maryland Bridge was cemented using adhesive system and dual cure cement. The restoration was used as temporary rehabilitation until the impression procedures.The prosthetic phase was performed after 3 months from implant insertion. A digital workflow was used. A scan body was placed directly on the transmucosal implant neck without the need for a secondary surgery. A digital impression was acquired using the intraoral scanner, converted into an .stl file and sent to the dental laboratory. Exocad software was used to prepare the customized abutment, the temporary crown and the definitive restoration from the 3D printed models obtained from digital impression.The provisional resin crown was designed according to the Biologically Oriented Preparation Technique (BOPT). The finishing line ended at the implant hyperbolic with a moderate compression of peri-implant soft tissues. The crown was maintained for 21 days. Then definitive zirconium-ceramic crown was cemented with a polycarboxylate cement.RESULTSNo complications were observed during the follow-up. Soft tissue adaptation to the hyperbolic neck was observed, with high stability up to the 18-month.CONCLUSIONSThe use of a two-piece implant placed with a transmucosal technique and associated with a digital prosthetic workflow allowed an optimal rehabilitation in a highly aesthetic area with a minimally invasive approach.CLINICAL SIGNIFICANCEThe combined use of a minimally invasive surgical technique with transmucosal approach represents the first step of the proposed protocol. The healing phase guided by BOPT technique concepts and the use of intraoral scanners play a 3D biological approach in the evaluation of tissue morphology. The development of a fully digital workflow is possible and increases the predictability of clinical cases where aesthetic results is an important requisite.Digital impression technique with intraoral scanner can be considered particularly useful in association with implants placed transmucosal
Investigation on the functionality of thermoresponsive origami structures
Full text linkAdditive manufacturing (AM) has recently been introduced as a reliable technique for the fabrication of highly complex geometries that were not possible before. Due to the flexibility in the organization of material properties such as responsive elements in space, AM is now a capable technology for the production of smart structures that can transform their geometry, for example, from a compact state to a deployed configuration. Among others, fused deposition modeling (FDM) can reliably be used to manufacture polymeric constructs with high resolution. Polylactide (PLA), the most popular polymer in FDM printing is a shape-memory polymer. Therefore, the manufacturing of shape-transforming constructs can be simplified to the construction of foldable products that can be programmed simply by applying mechanical forces. Origami can then be used as a simple platform in which the shape-transforming of a programmed construct is via the folding of material through the thinner sections (hinges). Herein, PLA and FDM are used to fabricate foldable structures. The effects of different parameters namely total thickness, layer height, nozzle temperature, and activation temperature on the shape recovery of the manually programmed origami structures are then investigated
Evolving fabric and its impact on the shearing behaviour of a compacted clayey silt exposed to drying-wetting cycles
No full textThe fabric and the hydro-mechanical behaviour of compacted clayey silt samples were investigated before and after drying-wetting cycles. Drying-wetting cycles changed the soil fabric by increasing the macro-porosity, while the total void ratio remained almost constant. The cycled samples were more compressible than the original ones and experienced a smaller decrease of suction during shearing at constant water content. The higher compressibility is associated to a more evident reduction of macroporosity.
The smaller suction decrease is reproduced with a double structure water retention model accounting for changes in macro-porosity during shearing. Cycled samples mobilised higher strength and showed a higher dilatancy than original samples sheared at the same initial total stress and suction; furthermore, dilatancy increased with suction for both fabrics. The Li and Dafalias stress-dilatancy relationship, formulated in terms of a macro-structural Bishop stress and accounting for a suction dependency, allowed reproducing the experimental results accurately
Investigation on shape recovery of 3D printed honeycomb sandwich structure
No full textLightweight sandwich panels have been used in various industry sectors due to their unique properties as well as a high ratio of stiffness-to-weight and energy absorption. Three-dimensional (3D) printing process provides a unique opportunity to fabricate highly complex shapes of sandwich panels and also the application of smart materials, such as shape memory polymers, can create unique functionality for the 3D printed sandwich structure so that they can change their shape in response to external stimuli and give a new dimension to the printing process called four-dimensional (4D) printing. Polylactic acid is a biodegradable and compostable polymer with a good shape memory effect that can be printed easily with an inexpensive fused deposition modeling. This study investigated the effect of printing and activation parameters on the functionality, in particular shape recovery, of the deformed sandwich structure with honeycomb out-of-plane tailored core. The input parameters were the activation temperature, the nozzle temperature, and the printing velocity. The results showed that the optimum recovery ratio can be achieved using a higher activations and nozzle temperatures and lower printing speed
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