1,720,987 research outputs found
Capturing motions and forces of the human masticatory system to replicate chewing and to perform dental wear experiments
No full textOne way to evaluate the life-time performance of dental restorative materials is to use in vitro dental wear simulators, which generate accelerated artificial dental wear on dental restorative components outside of the human oral environment. However, the work of several researchers has questioned the reliability of these in vitro results as a consequence of significant result variations produced by different types of dental wear simulators testing identical dental specimens. Natural six degree of freedom (DOF) mandibular movements and other characteristics of the human masticatory system are not replicated by any of these available simulators. A simulator replicating and controlling 6 DOF mandibular movements and occlusal bite forces improves this situation. This paper presents a method by which accurate jaw motion data can be obtained using a conventional 6 DOF motion capturing system and a method of measuring occlusal bite forces. The data obtained have subsequently been used as input signals for a new 6 DOF dental wear simulator capable of generating single and multicontact wear formations in dental wear studies.One way to evaluate the life-time performance of dental restorative materials is to use in vitro dental wear simulators, which generate accelerated artificial dental wear on dental restorative components outside of the human oral environment. However, the work of several researchers has questioned the reliability of these in vitro results as a consequence of significant result variations produced by different types of dental wear simulators testing identical dental specimens. Natural six degree of freedom (DOF) mandibular movements and other characteristics of the human masticatory system are not replicated by any of these available simulators. A simulator replicating and controlling 6 DOF mandibular movements and occlusal bite forces improves this situation. This paper presents a method by which accurate jaw motion data can be obtained using a conventional 6 DOF motion capturing system and a method of measuring occlusal bite forces. The data obtained have subsequently been used as input signals for a new 6 DOF dental wear simulator capable of generating single and multicontact wear formations in dental wear studies
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
Grid computing for detailed hemodynamics-simulation-based planning of endovascular interventions
No full textDetailed numerical simulations of blood flow in arteries with various malformations and its conjugate loads on the vessel walls have been a research topic for specialized medical and engineering communities over decades. The present state of computing resources and software allows access to these elaborate diagnostic and research tools to a broad user circle and even to integrate them into clinical workflows. To tap the full potential of hemodynamic simulations, a Grid-based “virtual vessel surgery” application has been developed and deployed as part of the image processing module of the MediGRID project of the German Federal Ministry of Education and Science (BMBF). The very resource-intensive parts of that application, including not only the numerical simulation itself, but also automated data pre- and post-processing and visualization are implemented and are made available through the MediGRID portal. Some highly interactive workflow steps of the application are left at the user site but automated – via a specially developed Web interface – to a degree allowing intuitive, fast interaction and seamless integration with the Grid components. Standard middleware provided by D-Grid is used throughout. The complete workflow is implemented into the grid and can in principle be carried out using no external software. It was applied to real vessel data with a stenosis and an aneurysm, respectively
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
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