1,720,974 research outputs found
Overlapping Schwarz preconditioners for indefinite time harmonic Maxwell equations
No full textGopalakrishnan, Jayadeep; Pasciak, Joseph E.. (2000). Overlapping Schwarz preconditioners for indefinite time harmonic Maxwell equations. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/3471
An analysis of the practical DPG method
No full text1 online resource (PDF, 14 pages)Gopalakrishnan, Jayadeep; Qiu, W.. (2011). An analysis of the practical DPG method. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/181114
A characterization of hybridized mixed methods for second order elliptic problems
No full textIn this paper, we give a new characterization of the approximate solution given by hybridized mixed methods for second-order, self-adjoint elliptic problems. We apply this characterization to obtain an explicit formula for the entries of the matrix equation for the Lagrange multiplier unknowns resulting from hybridization. We also obtain necessary and sufficient conditions under which the multipliers of the Raviart-Thomas and the Brezzi-Douglas-Marini methods of similar order are identical.Cockburn, Bernardo; Gopalakrishnan, Jayadeep. (2002). A characterization of hybridized mixed methods for second order elliptic problems. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/3849
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
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
Degree and wavenumber [in]dependence of a Schwarz preconditioner for the DPG method'
No full textAbstract
This note describes an implementation of a discontinuous Petrov Galerkin
(DPG) method for acoustic waves within the framework of high order finite el-
ements provided by the software package NGSolve. A technique to impose the
impedance boundary condition weakly is indicated. Numerical results from this im-
plementation show that a multiplicative Schwarz algorithm, with no coarse solve,
provides a
p
-preconditioner for solving the DPG system. The numerical observa-
tions suggest that the condition number of the preconditioned system is independent
of the frequency
k
and the polynomial degree
p
A multilevel discontinuous Galerkin method
No full textA variable V-cycle preconditioner for an interior penalty finite element discretization for elliptic problems is presented. An analysis under a mild regularity assumption shows that the preconditioner is uniform. The interior penalty method is then combined with a discontinuous Galerkin scheme to arrive at a discretization scheme for an advection-diffusion problem, for which an error estimate is proved. A multigrid algorithm for this method is presented, and numerical experiments indicating its robustness with respect to diffusion coefficient are reported.Gopalakrishnan, Jayadeep; Kanschat, Guido. (2000). A multilevel discontinuous Galerkin method. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/3501
Mortar Estimates Independent of Number of Subdomains
Full text linkThe stability and error estimates for the mortar finite element method are well established. This work examines the dependence of constants in these estimates on shape and number of subdomains. By means of a Poincar´e inequality and some scaling arguments, these estimates are found not to deteriorate with increase in number of subdomains
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