1,720,990 research outputs found
Traveling waves for several equations of mathematical physics-existence and profiles
No full textV. Camacho, R. Guy, and J. Jacobsen studied traveling waves and shocks in viscoelastic generalization of Burger's equations.The vave profiles are given by
using the numerical approach and by giving the corresponding computer
visualizations. In this paper we propose a purely mathematical
approach to the same problem and give a qualitative picture of the
behavior of these waves
A general framework for some economic problems with uncertainty and exogenous barriers
No full textThis paper provides analytical solutions and regularity results for some second order PDEs of degenerate elliptic type. The motivation is to study several economic models with uncertainty where the variables are constrained by constant barriers
On nonlinear Black-Scholes equations
No full textThis paper revisits some solution methods for Black-Scholes equation and some of its nonlinear versions arising in option pricing theory
Boundary-value problems for second order partial differential equations arising in risk management and cellular neural networks approach
No full textA boundary value problem arising in risk management is studied in a multidimensional framework. Analytical solutions are obtained and numerical investigation of some real-world examples is performed throughout the CNN approach
Global properties in spaces of generalized functions on the torus for second order differential operators with variable coefficients
No full textAbstract. The present paper studies global hypoellipticity and global solvability on the two dimensionai torus T 2 for a class of second order differential operators with variable coefficients in the framework of C°°(T 2 ) and Gevrey G ff (T 2 ), 1 < a < co spaces. The class of operators under consideration contains hyperbolic, elliptic and parabolic type operators with degeneracy. Necessary and/or sufficient conditions for global solvability and global hypoellipticity are proposed. In the hyperbolic case Siegel type conditions on diophantine approximations of the averages of some coefficients of the corresponding operators occur. Further for every a > 1 we exhibit first order real principal type operators on the torus T 2 which are globally G 9 hypoelliptic if 1 < 6 < a but are not globally C°° and G 9 hypoelliptic for 0 > a. A global hypoellipticity result is also proved for semilinear perturbations of degenerate elliptic operators
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Nonlinear estimates in anisotropic Gevrey spaces
Get PDFWe introduce scales of Banach spaces of anisotropic Gevrey functions depending on multidimensional parameters. We prove estimates in such spaces for composition maps and nonlinearities in conservative forms. Applications for solvability and regularity of solutions of nonlinear PDEs are outlined
Variations on the Author
Get PDF“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
Get PDFWe 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
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