1,721,111 research outputs found
Résultats en simulation de l’utilisation d’un robot avec flexibilités pour l’usinage et le soudage
Get PDFThe objective of this report is to detail the models used in simulation and the results obtained in simulation for both machining and FSW process. This report contains in a first part the details of modeling flexibilities of serial robots primarily through a model of localized flexibilities. The flexibilities are expressed both in Cartesian space and in the joint space and taking into account possible couplings. The second part deals with the dynamic model used in the simulator and the simulation environment. A significant work was to also model the company Kuka robot controller. Machining processes and FSW are modeled by simple models but reflecting the reality of the behavior.L’objectif de ce rapport est de détailler les modèles utilisés en simulation et les résultats obtenus en simulation aussi bien pour le procédé d’usinage que pour le procédé FSW. Ce rapport contient donc dans une première partie les détails sur la modélisation des flexibilités des robots essentiellement par le biais d’un modèle de flexibilités localisées. Les flexibilités sont exprimées aussi bien dans l’espace cartésien des robots que dans l’espace articulaire et en tenant compte des éventuels couplages. Une seconde partie traite du modèle dynamique utilisé dans le simulateur et de l’environnement de simulation. Un travail non négligeable a été de modéliser également le contrôleur de robot de l’entreprise Kuka. Les procédés d’usinage et de soudage FSW sont modélisés par des modèles simples mais traduisant bien la réalité du comportement.ANR COROUSS
Rapport de définition de l’ensemble des essais
Get PDFCe rapport contient la définition des pièces d’essais utilisées pour la validation des tâches, d’une part en soudage FSW et d’autre part en usinage, qu’il soit de pièces aluminium ou de pièces en matériaux composites. La robotisation du FSW est envisagée pour les soudures complexes pouvant occuper un volume de travail conséquent. La déformation du robot, à efforts de soudage équivalent, peuvent donc évoluer tout au long de la soudure. Les pièces de démonstration doivent permettre de valider ou d’estimer l’efficacité des corrections de trajectoires pour des soudures : Générant par leur géométrie des variations d’effort de soudage (avance et transverse) et des positions du robot différentes conduisant à des sollicitations de ces axes également différentes. Pour la validation du potentiel d’usinage à l’aide de robots, nous avons choisi de mener les tests sur des pièces composites de grandes dimensions. Il s’agit de pièces qui rentrent dans le cadre d’une nouvelle approche en termes de construction aéronautique, concernant la conception, la fabrication et la validation d’un démonstrateur de caisson d’avion d’affaires en composite. Ce projet avait permis, pour ce qui concerne le détourage des pièces composites, la détermination de conditions opératoires optimales. Ce rapport présente le cas des pièces à tester ainsi que le moyen qui a été déterminé et exploité pour mener ces essais.ANR COROUSS
Placement optimal de tâches et gestion de la redondance
Get PDFThis deliverable introduces a methodology that aims to determine the best placement of the workpiece to be machined knowing the cutting forces exerted on the tool and the elastostatic model of the robot. A machining quality criterion is proposed and an optimization problem is formulated and solved. The KUKAKR270-2 robot is used as an illustrative example throughout the report. A workpiece test and the cutting forces applied by the workpiece on the tool along the machined path are given as an illustrative example. Then, a mono-objective optimization problem is formulated and solved in order to find the optimum placement of the workpiece test with regard to a proposed machining quality criterion. As a result, the optimum and the worst workpiece placements are illustrated within the robotic cell. Moreover, the best and the worst redundancy planning schemes associated with those placements are determined.ANR COROUSS
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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