1,720,979 research outputs found
Asymptotic behavior of solutions for time-delayed nonlocal dispersion equations with Dirichlet boundary
No full textThis paper is concerned with the asymptotic behavior of the solutions for Nicholson's blowflies equation with nonlocal dispersion subjected to Dirichlet boundary condition. We first prove the existence and uniqueness of the solution for the initial boundary value problem and its non-trivial steady state. Then we give a threshold result on global stability of equilibria: when D lambda(1) + delta > p, the solution time-exponentially converges to the constant equilibrium 0 for any large initial data; when D lambda(1) + d < p, the solution time-asymptotically converges to its positive steady-state f(x) for any large initial data, once 1 < p d = e, where D> 0 is the diffusion coefficient, d > 0 is the death rate, p> 0 is the birth rate and.1 > 0 is the principal eigenvalue for the nonlocal characteristic equation. The adopted approach is the energy method and the monotonic technique
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
A Preliminary Result of Implementing a Deep Learning-Based Earthquake Early Warning System in Italy
No full textIn this paper we present the preliminary results of a study using a deep-learning tool named LSTM (Long Short-Term Memory) network, to classify seismic events as near-source and far-source, with the final purpose of developing efficient earthquake early warning systems. We use a similar approach as in [15], applied to a database, named Instance, containing information about 54,008 earthquakes that occurred in Italy. Although these are preliminary results, the method shows a good ability to detect far-source events with an accuracy of about 67 %. For near-source events, the method shows an improvable result with an accuracy of 57 %. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG
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
UNIFORM ATTRACTOR OF IMPULSE-PERTURBED REACTION-DIFFUSION SYSTEM
No full textThe paper deals with the existence and invariance of uniform attractors of impulseperturbed reaction-diffusion system. Moments of impulsive perturbation are not fixed and are determined by the getting of trajectory into a given subset M of the phase space. At the moment of getting, the phase variable undergoes a fixed increment. It is proved that such a problem generates impulsive dynamical system that has the uniform attractor Θ, and the set Θ\ M is invariant with respect to the impulsive semiflow
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