1,720,967 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
A comprehensive methodology to assess human bone transversal toughness based on macroscopic specimens, the compliance method, and 3D bio-faithful numerical simulations
No full textInternational audienceThis study proposes a method for assessing the transverse toughness of human long-bone cortical tissue. The method is based on a three-point bending test of pre-notched femur diaphysis segments, post-processed using the compliance method coupled with numerical simulations. Given the cracking nature of bone and if cracking processes remain confined to the crack tip, it is assumed that the compliance method can be used. Numerical simulations are based on a bio-faithful 3D reconstruction of the bones tested and a detailed consideration of the boundary and loading conditions of the mechanical test. The resulting toughness values obtained on embalmed bones range from Gc=4.3 to 7.1 N/mm. The assumptions made, the biofidelity of the simulations, and the ability of the method to determine an intrinsic toughness value of cortical bone, considered a heterogeneous material, are discussed. Although related to embalmed bones, and considering the limitations this state can induce, the toughness values obtained are consistent with data from the literature. Due to the larger specimen size, they are also more realistic, ensuring a complete description of the material’s crack extension resistance curve. They mainly characterize the medial and lateral quadrants of the bone transversal section. The study concludes that the proposed method provides a robust approach for assessing bone transversal toughness
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
Modeling one-handed grip strangulation: Intentionality of the gesture and age influence
No full textInternational audienc
Crack propagation experiment on long human bone
No full textInternational audienceMechanical testing on complex media such as bone for crack propagation is a field of investigation in which numerous studies have been published. The global majority of studies focuses on the understanding of mechanisms at microscopic or nanoscopic scales (Giner et al. 2017; Granke et al. 2016; Zioupos and Currey 1998). Tests are often performed on smallsamples with controlled geometry. It ensures reasonable control of boundary conditions, but the main counterpart remains with the small dimensions of the samples, requiring dedicated devices and being at risks of non-negligible scale effects (Choi et al. 1990; Zioupos and Currey 1998). An experimental procedure has been developed to carry out a crack propagation test on long human bones. This choice is justified by a mean of comprehension of macrocracks propagation in human cortical bone, taking into account their specific geometry. The scale of the experiment has to remain consistent with the one of future modelling as this work is part of a project focusing on the development of a probabilistic model to predict bone cracking. The experiment is a three-point bending test performed on a notched shaft segment of bone taken in the middiaphysis of a human femur. The test is controlled by the notch opening displacement (NOD). Only the cortical part of the bone is considered here.The paper presents the experimental cracking test for macrocrack propagation in long human femoral bones, describing equipment and methods. Some typical results are given. Then, comments and conclusions are drawn
Crack propagation in grooved long bone segment
No full textInternational audienceThe following paper is an english translation of the scientific article "T. Kurtz, Y. Godio-Raboutet, and J.-L. Tailhan. Propagation de fissure sur tronçon d'os long rainuré. 25 ème congrès français de mécanique, nantes, france. 2022." [1]. The original version is published in french along the work presented during the 25 th French Congress of Mechanics in Nantes (from August 29 th to September 2 nd of 2022).URL link to the original article : https://hal.science/hal-04280203v1A mechanical test of macrocrack propagation in a cortical bone shaft is developed to comprehend the failure mechanisms at this scale and identify fracture processes, which are paramount to a future modelisation. A first set of three-point bending tests was performed on notched segments of human femoral dyaphisis [2, 3]. However, macrocrack orientation is influenced by the material’s anisotropy. In order to drive cracking processes in the transversal direction only, a modification of the testing protocol is submitted.From work found in the litterature [4, 5], notched shafts are previously grooved : a hemispherical groove is milled on the external surface of the bone to guide the crack in the transversal direction in the notch section. Special care is taken for the three-point bending test allowing a mastered procedure despite geometric variability of specimens : positioning and boundary conditions of the samples, notch displacement sensor’s supports alignment regarding bone axis, positioning and height of the notch, constant groove’s depth. The hydraulic jack is driven indirectly with the notch opening, measured with an inductive displacement sensor. A series of unloading/reloading cycles are done to plot residual quantities, pre-peak damage and macrocrack propagation in post-peak.Obtained results are expressed in terms of loading as a function of the notch opening displacement. Load-unloading cycles and residual openings analysis highlight the prominent role of cracking in failure mechanisms. Results show that the residual opening is directly linked to a structural weakening, consequently to the cracking processes, and that no plasticity is found at this scale. Cycles analysis allows us to develop a hypothesis about the role of internal residual stresses on permanent deformation. Furthermore, results point out that the groove guides the macrocrack in the transversal direction. Comparison between results on non-grooved samples exhibits the impact of the geometric feature. Future perspectives rely on the reverse analysis determination of the mechanical properties in the transversal direction
- …
