1,721,111 research outputs found
Analisi Matematica
No full textAnalisi Matematica e` un testo che:
* offre una gamma completa degli argomenti classici dei corsi di base di Analisi Matematica;
* accoglie le esigenze dei corsi dei nuovi ordinamenti didattici;
* e` scritto in modo accessibile per lo studente, senza rinunciare al rigore matematico;
* lascia un alto grado di liberta` al docente nell’impostazione delle lezioni.
Il testo contiene, oltre a ‘‘quasi’’ tutti gli argomenti standard dei ‘‘vecchi’’ corsi di Analisi Matematica 1 e 2, un’introduzione alle funzioni olomorfe, alle serie di Fourier, alle trasformate di Laplace e di Fourier e al concetto di stabilita’ per soluzioni di equazioni differenziali ordinarie. Il ‘‘quasi’’ si riferisce al concetto di convergenza uniforme, piu`adatto a un corso avanzato
A system of degenerate parabolic nonlinear PDE's: a new free boundary problem
No full textWe prove existence of solutions of a new free boundary problem described by a system of degenerate parabolic equations. The problem arises in petroleum engineering and concerns fluid flows in diatomite rocks. The unknown functions represent the pressure of the fluid and a damage parameter of the porous rock. These quantities are not necessarily continuous on the free boundary, which considerably complicates the mathematical analysis
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
Traveling wave solutions of a nonlinear degenerate parabolic system from petroleum engineering
No full textWe study existence and qualitative properties of traveling wave solutions of a new free boundary problem which describes fluid flow in diatomite rocks. Diatomites are rather fragile and are characterized by a low permeability, which can increase due to the nonlocal accumulation of damage caused by the fluid flow. The traveling wave solutions give insight in the behavior near the free boundaries and show a strong parameter dependence. In particular we find in certain parameter ranges solutions with discontinuities across the free boundaries
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
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