1,721,437 research outputs found
On the implementation of a finite volumes scheme with monotone transmission conditions for scalar conservation laws on a star-shaped network
No full textIn this paper we validate the implementation of the numerical scheme proposed in [3]. The validation is made by comparison with an explicit solution here obtained, and the solutions of Riemann problems for several networks. We then perform some simulations in order to qualitatively validate the model under consideration. Such results represent also a first step for the validation of the finite volumes scheme introduced in [14]
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
A fast-convolution based space–time Chebyshev spectral method for peridynamic models
No full textPeridynamics is a nonlocal generalization of continuum mechanics theory which addresses discontinuous problems without using partial derivatives and replacing them by an integral operator. As a consequence, it finds applications in the framework of the development and evolution of fractures and damages in elastic materials. In this paper we consider a one-dimensional nonlinear model of peridynamics and propose a suitable two-dimensional fast-convolution spectral method based on Chebyshev polynomials to solve the model. This choice allows us to gain the same accuracy both in space and time. We show the convergence of the method and perform several simulations to study the performance of the spectral scheme
SPECTRAL COLLOCATION METHODS FOR NONLOCAL PROBLEMS IN BOND-BASED PERIDYNAMIC MODELS
No full textPeridynamics is a nonlocal theory generalizing elasticity theory
able to model the spontaneous formation and the evolution of discontinuities
in materials. In the bond-based formulation, the peridynamic operator is char
acterized by the presence of a convolution kernel, and this suggests discretizing
the model by spectral methods. This manuscript aims to provide a coincise
description of the theory together with a review of its discretization by spectral
collocation methods
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
A Traffic Model with Junction Constraints for Smart Cities Development
No full textGood environmental quality is the foundation for a good quality of life. Technologies of Smart Cities can adequately support the path of sustainability in urban areas and thus compete to raise the quality of life of citizens. In particular, sustainable urban development concept can be characterized in terms of CO2 emissions. In order to address sustainable urban development, management and modeling traffic jam is a primary issue. We propose a mathematical model based on hyperbolic scalar conservation laws with non-local point constraint at the interface and a finite volume scheme to reproduce the capacity drop phenomenon at a road merge. We call capacity drop the situation in which the outflow through the junction is lower than the receiving capacity of the outgoing road, as too many vehicles trying to access the junction from the incoming roads hinder each other. The capability of representing such phenomenon by means of a non-local model allow us to obtain more accurate and detailed information by traffic data provided by sensors which can be used to propose a strategy to manage traffic flow near crossroads and to reduce the congestion in urban setting
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
On a salt fingers model
Full text linkWe consider the model introduced in Paparella and von Hardenberg (2014), that consists in the homogeneous boundary value problem for a system of nonlinear degenerate parabolic equations. We prove the existence of global weak solutions and discuss their stability and asymptotic properties
- …
