1,721,434 research outputs found
Spectral approximation of elliptic operators by the hybrid high-order method
No full textWe study the approximation of the spectrum of a second-order elliptic differential operator by the Hybrid High-Order (HHO) method. The HHO method is formulated using cell and face unknowns which are polynomials of some degree k ≥ 0. The key idea for the discrete eigenvalue problem is to introduce a discrete operator where the face unknowns have been eliminated. Using the abstract theory of spectral approximation of compact operators in Hilbert spaces, we prove that the eigenvalues converge as h 2t and the eigenfunctions as h t in the H 1 -seminorm, where h is the mesh-size, t ∈ [s, k + 1] depends on the smoothness of the eigenfunctions, and s > 1/2 results from the elliptic regularity theory. The convergence rates for smooth eigenfunctions are thus h 2k+2 for the eigenvalues and h k+1 for the eigenfunctions. Our theoretical findings, which improve recent error estimates for Hybridizable Discontinuous Galerkin (HDG) methods, are verified on various numerical examples including smooth and non-smooth eigenfunctions. Moreover, we observe numerically in one dimension for smooth eigenfunctions that the eigenvalues superconverge as h 2k+4 for a specific value of the stabilization parameter
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
Optimal Decision Making for Aircraft Maintenance Planning: From Maintenance Check Scheduling to Maintenance Task Allocation
No full textAircraft maintenance is the process of overhaul, repair, inspection, or modification of an aircraft or aircraft systems, components, and structures, to keep these in an airworthy condition. Airlines must perform regular maintenance on their fleet to keep their aircraft airworthy and, ultimately, prevent any systems or components failures during commercial operations. Coupled with the rapid growth of the global commercial aircraft fleet, aircraft maintenance demands have increased significantly in the past few decades. Since aviation is a very competitive industry, the growing aircraft maintenance demands and associated operation costs put a huge financial burden on airlines, forcing them to reduce costs while still respecting safety regulations. Therefore, airlines are laying increasing emphasis on planning aircraft maintenance efficiently. An efficient planning approach for aircraft maintenance is a dual-edged sword. It reduces not only the time and effort of organizing maintenance tasks and coordinating maintenance activities but also increases the time fleet availability for operations and associated revenues. Before introducing wide-body aircraft in the 1970s, airlines used a bottom-up, task-oriented approach to plan aircraft maintenance, as then the commercial fleet sizeswere small. Nowadays, most airlines adopt a top-down approach, and first groups the maintenance tasks with the same or similar inspection intervals into a large task block. These, in turn, are commonly divided into four types and labeled as: A-check (every 4–6 months), B-check (every 4–6 months), C-check (every 18–24 months), and Dcheck (every 6–10 years). After planning the letter checks, airlines further determine the maintenance tasks to be added or removed in each letter check. This dissertation innovates the aircraft maintenance planning (AMP) process by presenting a comprehensive digital solution. It replaces the current sequential computeraided manual approachwith an integrated scheduling methodology to automate the aircraft maintenance planning process. Given a specific time horizon, it considers all check types together when making the maintenance check decisions and generates the optimal schedules for all letter checks in one comprehensive solution. After that, it plans a long-term (3–5 years) task execution plan based on the optimal maintenance check schedule. These features are integrated into a decision suppAir Transport & Operation
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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