1,720,986 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
Modeling and characterization of non-ideal compressible flows in unconventional turbines
No full textThe vast majority of energy conversion systems currently makes use of fossil fuels, whose combustion generates harmful greenhouse gases. Transitioning to renewable energy sources is thus paramount to limiting the environmental impact of human activities on the climate. In this regard, the harvesting of wasted thermal energy constitutes a promising strategy to increase the efficiency of industrial processes and mobile engines. For instance, technologies such as organic Rankine cycle (ORC) systems enable the energy discarded during the conversion processes to the atmosphere to be repurposed and generate CO2-neutral electricity or additional mechanical work.The efficiency of such systems is subordinate to that of each of the components, among which, is the turbine. Designing more efficient ORC turbines inherently leads to a higher thermodynamic cycle efficiency. However, these turbines operate with complex organic compounds, and part of the expansion process often occurs in the dense vapor state, where the thermodynamic properties exhibit significant deviations from the variations predicted by the ideal gas law. As a consequence, available guidelines for the design of turbomachinery operating with air or steam cannot be used, as they would lead to incorrect sizing and wrong performance estimations. The development of generalized guidelines for turbine design is possible only through a thorough investigation of the internal non-ideal compressible flow inside the vane passage, and by accurately discerning all the possible loss sources.The research outlined in this thesis aims at characterizing non-ideal compressible internal flows of dense vapors and developing new guidelines for the design of unconventional turbines operating with organic fluids, such as those operating in organic Rankine cycle power systems.The influence of both the complexity of the fluid molecules and the thermodynamic state on the flow field is evaluated for some paradigmatic one-dimensional flow configurations. For these processes, loss mechanisms and relevant trends in flow variables are both qualitatively and quantitatively estimated. Moreover, a detailed analysis of the viscous dissipation in turbulent wall-bounded flows of dense vapor is performed by resorting to direct numerical simulations (DNS). Results are compared against those from an in-house reduced-order model (ROM) code solving the two-dimensional boundary layer equations.The combined effects of the working fluid, its thermodynamic state, and the flow compressibility on the flow deviation downstream of turbine cascades are then investigated by means of Reynolds Averaged Navier-Stokes (RANS) calculations on a representative geometry. The results obtained from the simulations are compared against those estimated with reduced-order physical models. Finally, an investigation of the influence of both compressibility and fluid molecular complexity on the optimal solidity of axial turbines is performed using RANS calculations. New design guidelines for the selection of optimal solidity in the preliminary design of non-conventional turbomachinery are proposed and discussed.Results show that turbines operating with compounds characterized by a high complexity of the molecular structure are arguably subjected to higher losses in the mixing region, as well as exhibiting larger viscous dissipation at a given Reynolds number. Moreover, the fluid strongly affects the operational range of the turbine, as well as its design.Flight Performance and Propulsio
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
High Fidelity Simulations and Modelling of Dissipation in Boundary Layers of Non-ideal Fluid Flows
No full textIn this work, we investigate the sources of dissipation in adiabatic boundary layers of non-ideal compressible fluid flows. Direct numerical simulations of transitional, zero-pressure gradient boundary layers are performed with an in-house solver considering two fluids characterized by different complexity of the fluid molecules, namely air and siloxane MM. Different sets of thermodynamic free stream boundary conditions are selected to evaluate the influence of the fluid state on the frictional loss and dissipation mechanisms. The thermo-physical properties of siloxane MM are obtained with a state-of-the-art equation of state. Results show that the dissipation due to both time-mean strain field and irreversible heat transfer, and the turbulent dissipation are significantly affected by both the molecular complexity of the fluid and its thermodynamic state. The dissipation coefficient calculated from the DNS is then compared against the one obtained from a reduced-order boundary layer CFD model [1] which has been extended to treat fluids modeled with arbitrary equations of state [7].Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Flight Performance and Propulsio
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