1,720,957 research outputs found
Synchronization of Uncertain Heterogeneous Agents: An Adaptive Virtual Model Reference Approach
No full textSynchronization of Multi-Agent Systems (MASs) has the potential to benefit many technologicalareas such as formation control for unmanned vehicles, cooperative adaptivecruise control, and spacecraft attitude control. Information plays a crucial role in MASs:in centralized approaches, a central node utilizes global information to achieve synchronization,while in distributed approach agents only utilize local information, i.e. neighbors’information. A big concern in MASs is the presence of parametric uncertainties(unknown dynamics), which might require adaptive control gains instead of fixed controlgains.This work thus provides a novel adaptive distributed control for MASs of heterogeneousagents with unknown dynamics based on model reference adaptive control (MRAC).We study both the synchronization of linear systems and the synchronization of Euler-Lagrange (EL) systems. The implementation of this scheme is based on distributedmatching condition assumptions. We study such matching conditions both for the statefeedbackcase and output-feedback case. Since all matching gains are unknown in viewof the unknown dynamics, the gains are adapted online via Lyapunov-based estimation.The asymptotic convergence of the synchronization error is analytically provenby introducing an appropriately defined Lyapunov function, and numerical examplesshow the effectiveness of the approach. The practical advantage of the proposed distributedMRAC is the possibility of handling unknown dynamics by simply exchangingthe states/output, and inputs with neighbors, without any extra auxiliary variables (distributedobserver) nor sliding mode. Because of the mutual dependence of control inputs,well-posedness problems will arise in the presence of cyclic communication, if the inputsare generated without a prescribed priority. In this work, we study such well-posednessproblems via parameter projection methods.Electrical Engineering | Embedded System
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
Leader–Follower Synchronization of Uncertain Euler–Lagrange Dynamics with Input Constraints
No full textThis paper addresses the problem of leader–follower synchronization of uncertain Euler–Lagrange systems under input constraints. The problem is solved in a distributed model reference adaptive control framework that includes positive μ-modification to address input constraints. The proposed design has the distinguishing features of updating the gains to synchronize the uncertain systems and of providing stable adaptation in the presence of input saturation. By using a matching condition assumption, a distributed inverse dynamics architecture is adopted to guarantee convergence to common dynamics. The design is studied analytically, and its performance is validated in simulation using spacecraft dynamics
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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