1,720,954 research outputs found
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
Resetting disturbance observers with application in compensation of bounded nonlinearities like hysteresis in piezo-actuators
No full textThis paper presents a novel nonlinear (reset) disturbance observer for dynamic compensation of bounded nonlinearities like hysteresis in piezoelectric actuators. Proposed Resetting Disturbance Observer (RDOB) utilizes a novel Constant-gain Lead-phase (CgLp) element based on the concept of reset control. The fundamental limitations of linear DOB which results in contradictory requirements and in a dependent design between DOB and feedback controller are analysed. Two different configurations of RDOB which attempt to alleviate these problems from different perspectives are presented and an example plant is used to highlight the improvement. Stability criteria are presented for both configurations. Performance improvement seen with both RDOB configurations compared to linear DOB is also verified on a practical piezoelectric setup for hysteresis compensation and results analysed.Accepted Author ManuscriptMechatronic Systems Desig
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
Proposed solutions for quantization induced performance deterioration in reset controllers
No full textThe most widely applied feedback controller is PID. This controller gains its popularity because of the ease of design through loop shaping, since PID can be analyzed in the frequency domain. However, PID is limited by linearity. Reset control is a nonlinear addition to PID control. Through linearization techniques it can be designed by analyzing the frequency domain. Through numerous numerical, analytical and practical experiments it has been shown that reset control can outperformPID. However, when practically implementing reset control, especially in motion stages, one aspect can cause severe performance degradation. Research is underrepresented in this field. Quantization can be described as discretization in the amplitude. This thesis aims to reduce the quantization induced performance degradation. Two methods are proposed: reset band and time regularization. Numerical analysis and practical experiments have been performed in order to analyze the performance degradation and proposed methods. Through the numerical analysis in matlab simulink of a mass system the performance degradation has clearly been addressed. Based on the new understanding tuning rules have been provided for both proposed methods. A preliminary sensitivity analysis shows the robustness of both methods. Both proposed methods show enhanced performance. In numerical analysis it was shown that the reset band solution and time regularization can achieve an improvement of up to 10 dB. It was shown through experiments on a high level motion stage that several dB improvement is feasible. For the reset band at a specifically detrimental frequency the error was reduced from 200 nm to 70 nm. The reset band shows an improvement of several dB. In one setup, the performance enhancement spanned a wide frequency range. Overall it is concluded that for quantization induced performance degradation both proposed methods clearly show improvement. Two novel applications of existing methods have shown an increase in performance. New tuning guidelines have been provided.CLOCMechanical Engineering | Mechatronic System Design (MSD
Multimode damping with activated metamaterials: Hexagonal patterned flexure with integrated piezo elements for active damping
No full textHigh Tech industry is looking to push the bounds of what is possible, this requires machines that run with ever increasing speed and precision for longer amount of time under progressively more hostile environments. These requirements necessitate the use of compliant mechanisms/flexures instead of traditional rigid body counterparts. However, as these flexures are pushed to operate at ever higher speeds, high frequency modes affect precision and hence require better damping. Currently active damping relies on a single or small amount of actuators which makes their placement for multimode damping inefficient. To this end, the MetaMech project was created which aims to combine the disciplines of mechatronics and metamaterials to create flexures with integrated cells housing sensors, active and passive dampers in optimal positions and orientations. This will enable more efficient placement and orientation of dampers, reducing the force and thus the size and weight needed to damp the system. This thesis takes the first step in this direction and is concerned with developing the first prototype demonstrator of a metamaterial flexure with integrated damping using currently available technology. The presentation will cover the design, Finite Element Analysis and practical tests of a hexagonal patterned metamaterial flexure with integrated piezo patches. It also presents the design and finite element analysis of a more advanced hexagonal cell able to exert force in three different directions. The results provide proof of concept for the MetaMech project with insights for future work.MetamechMechanical Engineering | Mechatronic System Design (MSD
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