1,720,974 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
On the assessment of Immersed Boundary Methods for fluid-structure interaction modelling: application to waste water pumps design and the inherent clogging issues
Full text linkThe meshing stage of a Computation Fluid Dynamics (CFD) problem is of crucial importance. In realistic engineering applications, issues arise when dealing with complex, sharp and moving boundaries, removing the possibility of automatic creation of a high quality structured mesh for instance. For Fluid-Structure Interaction (FSI) problems, the standard body-fitted meshing approaches are also limited to low structure deformation and to simple geometries. In light of these limitations, Immersed Boundary Methods (IBMs) have shown to be good alternatives for a broad range of problems.
The present work sets out to build a set of numerical methods based on IBMs to simulate both the motion of rigid bodies and the transport of thin flexible solids. This research focuses on the specific area of waste water pumps. Firstly, IBMs are used to provide estimates of the hydrodynamic performances of centrifugal pumps. Secondly, this type of method is used to give a first answer regarding the characterization of the physical mechanism that leads to clogging in such pumps.
The numerical tool is coupled to two different solvers for the fluid equations: (i) Navier-Stokes (NS) and (ii) Lattice-Boltzmann (LB). In the NS context, a sharp IBM based on a penalization method is developed and implemented in the open source library OpenFOAM in order to model the flow around rigid bodies. The complete model includes correction of the boundary conditions at the fluid-solid interface to improve the accuracy of the solution and coupling with turbulence models. To model the transport and the deformation of flexible structures, a diffuse penalty based IBM coupled to a solid model based on the variational derivative of the deformation energy is considered. In the LB context, the diffuse IBM available in the open source library Palabos is assessed for one-way coupling problems with rigid bodies. The latter is extended and coupled to the same solid model as above in order to study flexible structures.
The capabilities and the accuracy of the two IBMs are assessed and compared with several test cases dealing with rigid bodies. For the sharp NS-IBM, numerical results of academic cases highlight the benefits brought by the corrections of the interface boundary conditions. In engineering cases, the method leads to results in good agreement with experimental data and numerical data from standard body-fitted simulations. Finally, for the IBMs aimed at modelling the flexible structures, both physical approaches compare well with previous numerical models in literature, and are giving promising results regarding the clogging mechanism
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
Numerical study of Ventricular Assist Devices for optimizing their utilization and reducing clinical complications
No full textL'insuffisance cardiaque est une maladie mortelle très répandue au sein du monde moderne. Faute de donneurs, diverses thérapies à long-terme ont été mises en place pour le traitement de l'insuffisance cardiaque terminale. Parmi elles, l'assistance ventriculaire présente des taux de survies comparables à ceux obtenus avec une greffe de cœur. Cependant, de nombreuses complications cliniques liées à l'assistance ventriculaire perturbent toujours la vie des patients en engageant parfois leur pronostic vital. Une utilisation optimisée des dispositifs d'assistance ventriculaire permettrait de réduire le risque d'apparition de ces complications. La connaissance de l'impact des conditions de fonctionnement du dispositif sur la physiologie permet de limiter les dommages mécaniques cellulaires, de maîtriser le couplage entre la machine et le cœur tout en assurant un flux adapté au réseau cardiovasculaire du patient. Dans cette thèse, nous avons développé des modèles numériques basés sur le calcul CFD et l'analogie électro-hydraulique permettant d'identifier les modes de fonctionnement optimaux de ces dispositifs en prenant en compte des paramètres hémolytiques et physiologiques de l'écoulement sanguin. Premièrement, un modèle CFD d'un dispositif est proposé dans le but d'évaluer l'interaction de celui-ci avec le fluide composé de cellules vivantes qu'est le sang. Deuxièmement, les résultats du modèle CFD servent de base à l'établissement d'un modèle adimensionnel de la pompe, qui, couplé avec une modélisation électro-hydraulique du réseau cardiovasculaire, permet d'étudier les interactions entre le dispositif et le ventricule qu'il assiste. Enfin, ce modèle proposé ici est sollicité dans le but de fournir des résultats clés sur l'assistance circulatoire suite à une intervention chirurgicale innovante. L'ensemble des modèles sont validés par rapport à des données expérimentales disponible dans la littérature scientifique. Ils fournissent des éléments de réponse ainsi que des suggestions au corps médical sur le choix des conditions de fonctionnement des dispositifs. Ces suggestions sont basées sur les résultats physiologiques des différentes modèles numériques proposés dans cette thèse. Ils permettent d'identifier les conditions de fonctionnement selon lesquelles le patient est le moins susceptible d'être victime de complication clinique.Heart failure is a highly prevalent life-threatening disease in the modern world. Due Heart failure is a highly prevalent and deadly disease in the modern world. Due to a shortage of donors, various long-term therapies have been implemented for the treatment of end-stage heart failure. Among them, ventricular assistance presents survival rates comparable to those achieved with a heart transplant. However, numerous clinical complications associated with ventricular assistance still disrupt patients' lives and sometimes endanger their prognosis. An optimized use of ventricular assistance devices would help reduce the risk of these complications. Understanding the impact of device operating conditions on physiology allows for the limitation of cellular mechanical damage, control of the coupling between the machine and the heart, and ensuring an appropriate flow to the patient's cardiovascular system. In this thesis, we have developed numerical models based on computational fluid dynamics (CFD) and electro-hydraulic analogy to identify optimal operating modes for these devices, considering hemolytic and physiological parameters of blood flow. Firstly, a CFD model of a device is proposed to evaluate its interaction with the fluid composed of living cells, which is blood. Secondly, the CFD model results serve as a basis for establishing an adimensional pump model that, coupled with an electro-hydraulic model of the cardiovascular system, enables the study of interactions between the device and the assisted ventricle. Finally, this proposed model is utilized to provide key findings on circulatory assistance following an innovative surgical intervention. All the models are validated against experimental data available in the scientific literature. They provide insights and suggestions to the medical community regarding the choice of device operating conditions. These suggestions are based on the physiological outcomes of the various numerical models proposed in this thesis and help identify the operating conditions in which the patient is least likely to experience clinical complications
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
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