1,721,075 research outputs found
Asymptotic analysis and domain decomposition for a biharmonic problem in a thin multi-structure
No full textIn the paper, we consider the Dirichlet boundary value problem for the biharmonic equation defined in a thin T-like shaped structure. Our goal is to construct an asymptotic expansion of its solution. We provide error estimates and also introduce and justify the asymptotic partial domain decomposition for this problem
Stokes-Brinkman equations with diffusion and convection in thin tube structures
No full textThe steady state Stokes-Brinkman equations coupled with a system of diffusion-convection equations in a thin tube structure is considered. The Brinkman term differs from zero only in small balls near the ends of the tubes. The boundary conditions are: given pressure and concentrations at the inflow and outflow of the tube structure, the no slip boundary condition on the lateral boundary for the fluid, and Neumann type condition on the lateral boundary for the diffusion-convection equations. In this paper, the existence, uniqueness, and stability of the solution to such a problem are proved. Moreover, some a priori norm-estimates depending on the small thickness of the tubes are also provided. This model is well suited to describing thrombosis in blood vessels
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
Method of Asymptotic Partial Domain Decomposition for Non-steady Problems: Wave Equation on a Thin Structure
No full textInternational audienc
Method of asymptotic partial decomposition of domain for multistructures
Full text linkMethod of asymptotic partial decomposition of a domain (MAPDD) proposed and justified earlier for thin domains (rod structures, tube structures) is generalized and justified for the multistructures, i.e. domains consisting of a set of thin cylinders connecting some massive 3D domains. In the present paper, the Dirichlet boundary value problem for the steady-state Stokes equations is considered. This problem is reduced to the Stokes equations in the massive domains coupled with the Poiseuille-type flows within the thin cylinders at some distance from the bases (the MAPDD approximation problem). The high-order estimates for the difference of the exact solution to the initial problem and the solution to the MAPDD approximation problem is proved.Russian Scientific Foundation
14-11-00306 /
LABEX MILYON of University of Lyon, within the program "Investissements d'Avenir"
ANR-10-LABX-0070
ANR-11-IDEX-000
Homogenization for periodic media: from microscale to macroscale
No full textInternational audienceThe mathematical tools for the up-scaling from micro to macro in periodic media are considered: the homogenization techniques, the multiscale modelling, etc. The main applications of these tools are the mechanics of composite materials, flows in porous media, and discrete models for nanostructure
Homogenization and multicontinuum models for high contrast composites
No full textInternational audienceAbstract We consider the high contrast periodic composite materials having high ratio ω >>1 of physical constants of the components such as the heat conductivity or Young’s moduli. The ratio of the characteristic microscopic size and the characteristic macroscopic size is a small parameter e. If the component having high constants has the shape of small isolated particles then the homogenized (macroscopic, effective) model demonstrates a loss of the effective wave velocity. If the topology of the component having high constants corresponds to several (at least two) connected periodic sets disconnected one from other and if ε2ω>>1 or ε2ω = const then the macroscopic model is described by a multicontinuum, i.e. several continua in each point
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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