1,720,961 research outputs found
Bio-inspired control of the collective movements of a swarm of drones and applications to operational scenarios
No full textLa thèse, intitulée "Contrôle bio-inspiré d'un essaim de drones pour le mouvement collectif et l'applicabilité aux scénarios opérationnels", explore l'application d'un modèle bio-inspiré de mouvement collectif, inspiré du comportement d'une espèce de poisson, pour guider et coordonner un essaim de drones dans divers contextes et environnements. Les objectifs principaux de la thèse sont de comprendre le modèle biologique, de l'adapter à un algorithme de guidage 3D, de le valider avec des simulations et des expériences, et de l'améliorer avec des capacités de navigation, d'évitement d'obstacles et d'exploration.Dans un premier temps, une revue des modèles biologiques et des stratégies de contrôle des essaims de drones, se concentre sur les avantages et les défis des approches bio-inspirées, les concepts et les architectures de la robotique en essaim, et les problèmes de perception et de communication dans un essaim de drones. Par la suite, un modèle bio-inspiré de mouvement collectif, basé sur le poisson Hemigrammus rhodostomus, a été adapté pour être utilisé comme algorithme de guidage 2D pour les drones. Le modèle est mis en œuvre et validé avec des simulations et des expériences dans une arène de vol, démontrant l'émergence de comportements collectifs. Afin d'exploiter au mieux les capacités de vol des drones, le modèle est étendu à un algorithme de guidage 3D en ajoutant un terme d'interaction verticale. L'impact de cette interaction sur les comportements collectifs est analysé avec des simulations, montrant la modulation de la cohésion de l'essaim et la possibilité d'utiliser des phases collectives pour le contrôle opérationnel de l'essaim. L'une des propriété intéressante qui découle de ces modèles est la notion de phases. L'étude de la transition entre ces phases sous différents environnements stressants, tels que le bruit, les perturbations et les évitement d'ennemi, met en avant les propriétés de résilience de l'essaim. Un terme de répulsion envers un drone ennemi est ajouté au modèle, et son effet sur la dynamique de l'essaim est évalué avec des simulations et des expériences. Certaines de ces expérimentations ont pu être réalisées en extérieur avec un grand nombre de drones, démontrant la faisabilité et la robustesse du modèle bio-inspiré dans des scénarios réels. Pour finir, une discussion est ouverte sur les tâches de navigation, d'évitement d'obstacles et d'exploration pour l'essaim de drones, en utilisant le modèle bio-inspiré comme base. Quelques résultats préliminaires sont proposés, notamment des idées sur la manière de guider la flotte à travers des obstacles fixes, d'explorer des zones ou de suivre des gradients locaux, en utilisant différentes méthodes et outils.La thèse se conclut par une discussion générale sur les principales contributions et limites du modèle bio-inspiré, et quelques perspectives et orientations futures pour la recherche dans ce domaine.The thesis, titled “Bio-inspired control of a drone swarm for collective motion and applicability to operational scenarios,” explores the application of a bio-inspired model of collective motion, inspired by the behavior of a fish species, to guide and coordinate a swarm of drones in various contexts and environments. The main objectives of the thesis are to understand the biological model, adapt it to a 3D guidance algorithm, validate it with simulations and experiments, and enhance it with navigation, obstacle avoidance, and exploration capabilities.Initially, a review of biological models and drone swarm control strategies focuses on the advantages and challenges of bio-inspired approaches, the concepts and architectures of swarm robotics, and the perception and communication problems in a drone swarm. Subsequently, a bio-inspired model of collective motion, based on the Hemigrammus Rhodostomus fish, was adapted for use as a 2D guidance algorithm for drones. The model is implemented and validated with simulations and experiments in a flight arena, demonstrating the emergence of collective behaviors. The model is extended to a 3D guidance algorithm by adding a vertical interaction term to make the most of the drones' flight capabilities. The impact of this interaction on collective behaviors is analyzed with simulations, showing the modulation of swarm cohesion and the possibility of using collective phases for operational control of the swarm. One interesting property that emerges from these models is the concept of phases. The study of the transition between these phases under different stressful environments, such as noise, disturbances, and enemy avoidance, highlights the resilience properties of the swarm. A term of repulsion towards an enemy is added to the model, and its effect on the swarm dynamics is evaluated with simulations and experiments. Some of these experiments were conducted outdoors with a dozen of drones, demonstrating the feasibility and robustness of the bio-inspired model in real scenarios. Finally, a discussion is opened on the tasks of navigation, obstacle avoidance, and exploration for the drone swarm, using the bio-inspired model as a basis. Some preliminary results are proposed, including ideas on how to guide the fleet through fixed obstacles, explore areas, or follow local gradients using different methods and tools.The thesis concludes with a general discussion of the main contributions and limitations of the bio-inspired model and some perspectives and future directions for research in this field
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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