1,720,965 research outputs found
Boundary value problem for elliptic differential equations in non-commutative cases
No full textWe consider a boundary value problem for elliptic differential equations in non-commutative case
Abstract differential equations of elliptic type with general Robin boundary conditions in Hoelder spaces
No full textIn this article, we prove some new results on abstract second-order differential equations of elliptic type with general Robin boundary conditions. The study is performed in Holder spaces and uses the well-known Da Prato-Grisvard sum theory. We give necessary and sufficient conditions on the data to obtain a unique strict solution satisfying the maximal regularity property. This work completes the ones studied by Favini et al. [A. Favini, R. Labbas, S. Maingot, H. Tanabe, and A. Yagi, Necessary and sufficient conditions in the study of maximal regularity of elliptic differential equations in Holder spaces, Discrete Contin. Dyn. Syst. 22 (2008), pp. 973-987] and Cheggag et al. [M. Cheggag, A. Favini, R. Labbas, S. Maingot and A. Medeghri, Sturm-Liouville problems for an abstract differential equation of elliptic type in UMD spaces, Differ. Int. Eqns 21(9-10) (2008), pp. 981-1000]
Resolution and optimal regularity for a biharmonic equation with impedance boundary conditions and some generalizations
No full textA biharmonic equation with an impedance (non standard) boundary condition and more general equations are considered
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
Étude dans les espaces de Hölder de problèmes aux limites et de transmission dans un domaine avec couche mince.
No full textWe consider a family (Pδ)δ>0 of boundary value and transmission problems in a domain with thin layer, written in the form of second order abstract differential equation of elliptic type. A new approach for the resolution of (Pδ)δ>0 is presented in this work using the physical concept of impedance. This method is different of the one performing a rescaling in the thin layer, see [Favini A., Labbas R., Lemrabet K. and Maingot S.]. It leads to obtain direct and simplified problems. Where the thin layer effect is completely described by the impedance operator. The techniques employed are primarily based on the functional calculation of Dunford, the semigroups theory, the interpolation and some ideas of work in [R. Labbas, Thesis], [Dore G., Favini A., Labbas R., Lemrabet K. and Maingot S.] and [Favini A., Labbas R., Maingot S., Tanabe H., Yagi A.]. We obtain existence, uniqueness and maximal regularities new results in the Hölder spaces for the fixed and then we study the limit passage when δ→0 of (Pδ)δ>0. This work complete thus what was obtained in the framework Lp, see [Favini A., Labbas R., Lemrabet K. and Maingot S.].On considère une famille (Pδ)δ>0 de problèmes aux limites et de transmission dans un domaine avec couche mince, écrit sous la forme d'une équation différentielle d'ordre deux abstraite de type elliptique . Une nouvelle approche pour la résolution de (Pδ)δ>0 est présentée dans ce travail utilisant le concept physique d'impédance. Cette méthode est différente de celle qui utilise un changement d'échelle sur la couche mince voir [Favini A., Labbas R., Lemrabet K. and Maingot S.]. Elle permet d'obtenir un problème direct et simplifié où l'effet de la couche mince se retrouve complètement décrit par l'opérateur d'impédance. Les techniques employées sont essentiellement basées sur le calcul fonctionnel de Dunford, la théorie des semi-groupes, l'interpolation et quelques idées des travaux de [R. Labbas, Thèse d'état], [Dore G., Favini A., Labbas R., Lemrabet K. and Maingot S.] et [Favini A., Labbas R., Maingot S., Tanabe H., Yagi A.]. On obtient des résultats nouveaux d'existence, d'unicité et de régularité maximale dans les espaces de Hölder pour fixé et ensuite on étudie le passage à la limite quand δ→0 de (Pδ)δ>0. Ce travail complète ainsi ce qui a été obtenu dans le cadre Lp, voir [Favini A., Labbas R., Lemrabet K. and Maingot S.]
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
On a Degenerate Parabolic Problem in Holder Spaces
No full textIn this paper, we study some degenerate parabolic equation with Cauchy-Dirichlet boundary conditions. This problem is considered in little Holder spaces. The optimal regularity of the solution v is obtained and is specified in terms of those of the second member when some conditions upon the Holder exponent with respect to the degeneracy are satisfied. The proofs mainly use the sum theory of linear operators with or without density of domains and the results of smoothness obtained in the study of some abstract linear differential equations of elliptic type
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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