1,721,034 research outputs found
Series Elastic Actuation for Assistive Orthotic Devices: Case Study of Pneumatic Actuator
No full textWearable assistive robotics is a modern field where intelligent actuated systems work in collaboration with the body to replace a lost limb, to enhance performances (e.g. carrying load, walking, running, jumping) or to train or rehabilitate specific activities. Wearability (e.g. weight, bulkiness) and power are the two main competing characteristics of most assistive wearable devices. Energy efficient actuation systems with high power density per mass and volume are thus preferred. The biological muscle-tendon solution is very interesting for energy storage and generation of efficient cyclic patterns. The present study investigates on the capacity to replicate these biological properties using series elastic actuator (SEA) based on pneumatic cylinder technology. While classic SEA designs are composed of electric actuator in series with steel springs, pneumatic actuators are intrinsically compliant due to the compressibility of the fluid. The study starts by presenting an experimental approach for characterizing the elastic behavior of a pneumatic cylinder actuation targeting the assistance of the hip flexion. Results are then confronted to measurements of lower limb joints' stiffness observed during walking to identify the suitability of the solution with the targeted application..LSR
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
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