1,721,003 research outputs found
Experimentally validated structural finite element method analysis of a tibial intramedullary nail: Optimal choice of the contact settings
This article focuses on the static structural analysis of a tibial intramedullary nail, carried out by the finite element method. The investigated subject is concerned with the issue of frictional contacts that, generating a non-linear problem, play an important role in numerical analyses. Experimental tests were also developed on tibial intramedullary nail specimens. The experimental results, in terms of force–displacement, were used to calibrate and validate the finite element analysis, by tuning the contact parameters available in the software
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
“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
We 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
Finite element analysis of tapped thread joints: Setup of a computationally efficient modeling approach
This contribution deals with the efficient numerical modeling of tapped thread joints. Commercial FE packages provide different strategies to tackle the problem of modeling threaded joints, which is a recurrent one for the design engineer. Different modeling techniques are characterised by how the screw is modeled: either three-dimensional elements (thetra, hexa or wedge) or mono-dimensional elements (beam) can be used. In the case of three-dimensional approaches, the thread helix is seldom modeled: the actual geometry is often replaced by a plain cylinder and a suitable choice of contact settings between the screw and the "threaded" hole. In the case of road vehicles, due to the high number of threaded connections to be modeled, it is paramount to reach a trade-off between modeling accuracy and computational effort. This paper aims at comparing two modeling approaches, namely a three dimensional approach (baseline) and a mono-dimensional one (simplified model). Based on several criteria, such as equivalent stress on the screw shank, pressure distribution at the interface of the plates and in the underhead region, optimal contact settings for the simplified model are suggested. These settings allow replicating the results provided by the three-dimensional approach for given load case. The comparison is carried out on single lap, single screw joints, by the ANSYS R17 software. The methodology can be easily extended to other softwares or joint configurations
Optimizing the staging of melanoma patients for their best surgical management
Interval nodes (IN) are defined as lymph nodes that lie along the course of lymphatic collecting vessels between a primary tumor site and a draining node field. Sometimes INs contain metastases and a consensus on their surgical management is needed. Therefore, to optimize the surgical management of melanoma patients with metastatic lymphatic involvement, especially when the sentinel lymph node biopsy identifies an unusual drainage field, we identified patients treated at the Department of Plastic and Reconstruction Surgery of Bari between July 1994 and December 2012 identified with a primary-cutaneous melanoma who underwent lymphoscintigraphy and subsequent positive-IN the lymphadenectomy to evaluate the impact of this procedure on overall survival and disease-free-period. 51 patients presented INs, and lymphadenectomy (LA) of the subsequent lymphatic field was performed in 13 subjects with positive-IN. In 4 cases additional lymphatic metastases were detected in the usual basin beyond the IN+. Recurrence-free period and survival rate at 5 years were higher in patients with positive-IN who underwent LA than in subjects who underwent LA due to positive lymph nodes in the usual field. Immediate lymphadenectomy of the subsequent lymphatic field in patients with positive-INs may afford patients earlier stage treatment of their disease and improved prognosis
Fretting Fatigue in Mechanical Joints: A Literature Review
Fretting fatigue is a fatigue damage process that occurs when two surfaces in contact with each other are subjected to relative micro‐slip, causing a reduced fatigue life with respect to the plain fatigue case. Fretting has now been studied deeply for over 50 years, but still no univocal design approach has been universally accepted. This review presents a literature study that involves the three main types of mechanical joint affected by fretting fatigue (press‐fitted shaft hub joints, dovetail joints, and bolted joints) aiming at giving insight into the progress made in terms of design guidelines for engineers
Threaded fasteners with applied medium or high strength threadlockers: effect of different tightening procedures on the tribological response
Dispelling the Myths Behind First-author Citation Counts
We 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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