1,720,970 research outputs found
Event-based control tuning of propofol and remifentanil coadministration for general anaesthesia
No full textIn this study, the authors present robust tuning rules for an event-based control architecture for the automatic regulation of the depth of hypnosis in anaesthesia. The authors' control system uses propofol and remifentanil coadministration as control variables and the bispectral index as controlled variable. The control system is based on a PIDPlus controller combined with an event generator that detects significant variations of the BIS signal, thus providing strong filtering of the noise. A fixed ratio between the drug infusions allows the anaesthesiologist to explicitly regulate the opioid-hypnotic balance of the anaesthesia. The tuning rules are developed by solving a min-max optimisation problem that optimises the worst-case scenario over a given data set of patient models. A gain scheduling strategy yields optimal performance in both the induction and the maintenance phases of anaesthesia. Finally, through the Monte Carlo method, they validate the effectiveness of the proposed approach on a general population, and the robustness to the intra- and inter-patient variability for different infusion balances
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
Optimized tuning of an IMC scheme for depth of hypnosis control
No full textThis paper deals with the application of an Internal Model Control strategy to the regulation of the depth of hypnosis in general anesthesia, when propofol is used as hypnotic drug and the bispectral index scale is used as controlled variable. In particular, the inverse of the Hill function is used to linearize the system and then a standard internal model controller is applied. The internal model control filter time constants are determined by applying a particle swarm optimization algorithm on a set of patient models that describes a wide range of population. The Monte Carlo method is then used to demonstrate the robustness of the controller with respect to intra-patient and inter-patient variability
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
IR Light Sensing at the Edges of Glasses Lenses for Invisible Eye Tracking
No full textWe propose a novel readout configuration of photo detectors (PD) employed for infrared (IR) oculography placed on the lateral edges of the standard lenses of glasses for eye tracking. They collect the amount of light reflected by the IR-illuminated eyeball and captured by the lens, which guides it towards the edges. A set of discrete photodetectors is thus hidden inside the rims and their signals are fed to an agile artificial neural network (ANN) allowing to reconstruct the direction of the incident light, thus enabling the estimation of the direction of gaze. Here we report the experimental validation of this sensing approach on both a rectangular and prescription lens. The accuracy of the ANN inference applied to the current preliminary setup with 4 PDs is ~5° and ~25° for pitch and yaw respectively. The robustness of the detection was also tested under spurious IR illumination, which is fully rejected by a differential measurement. We believe that this approach will allow the combination of aesthetics, suitable accuracy and low-power needed to shift eye tracking from specific trial conditions and devices (such as headsets with bulky external batteries) to a pervasive, full-time feature of next-generation smart glasses
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