3,661 research outputs found
Cracked but not broken: the continued gender gap in senior administrative positions
Equality for women (and men) was enshrined in the Treaty of Rome in 1957. Legislatively this has meant that women have been treated in the same way as men, and post-feminist theory suggests that equality battles have been won and that women and men now have equal opportunities. However, when looking into the attainment of women in HE, the concept of equal opportunities seems questionable. Female administrative staff have outnumbered male administrative staff in universities for at least sixteen years. However, there is still an unbalanced gender profile at senior, ie above G9 (spine point >51 on the new single pay framework [UCU 2004]). If for professional managers at levels below that of Grade 10 women outweigh men by on average 62% why at levels at G10 and above do women represent on average only 30% of staff
Analysis of Schwarz methods for a hybridizable discontinuous Galerkin discretization
Schwarz methods are attractive parallel solvers for large scale linear
systems obtained when partial differential equations are discretized. For
hybridizable discontinuous Galerkin (HDG) methods, this is a relatively new
field of research, because HDG methods impose continuity across elements using
a Robin condition, while classical Schwarz solvers use Dirichlet transmission
conditions. Robin conditions are used in optimized Schwarz methods to get
faster convergence compared to classical Schwarz methods, and this even without
overlap, when the Robin parameter is well chosen. We present in this paper a
rigorous convergence analysis of Schwarz methods for the concrete case of
hybridizable interior penalty (IPH) method. We show that the penalization
parameter needed for convergence of IPH leads to slow convergence of the
classical additive Schwarz method, and propose a modified solver which leads to
much faster convergence. Our analysis is entirely at the discrete level, and
thus holds for arbitrary interfaces between two subdomains. We then generalize
the method to the case of many subdomains, including cross points, and obtain a
new class of preconditioners for Krylov subspace methods which exhibit better
convergence properties than the classical additive Schwarz preconditioner. We
illustrate our results with numerical experiments.Comment: 25 pages, 5 figures, 3 tables, accepted for publication in SINU
Cross-Points in Domain Decomposition Methods with a Finite Element Discretization
Non-overlapping domain decomposition methods necessarily have to exchange
Dirichlet and Neumann traces at interfaces in order to be able to converge to
the underlying mono-domain solution. Well known such non-overlapping methods
are the Dirichlet-Neumann method, the FETI and Neumann-Neumann methods, and
optimized Schwarz methods. For all these methods, cross-points in the domain
decomposition configuration where more than two subdomains meet do not pose any
problem at the continuous level, but care must be taken when the methods are
discretized. We show in this paper two possible approaches for the consistent
discretization of Neumann conditions at cross-points in a Finite Element
setting
Hybrid organizations as a strategy for supporting new product development
Alliances between large, well-established corporations and highly creative small companies or consultancies can be an effective method for promoting innovation
Designing Scalable Business Models
Digital business models are often designed for rapid growth, and some relatively young companies have indeed achieved global scale. However despite the visibility and importance of this phenomenon, analysis of scale and scalability remains underdeveloped in management literature. When it is addressed, analysis of this phenomenon is often over-influenced by arguments about economies of scale in production and distribution. To redress this omission, this paper draws on economic, organization and technology management literature to provide a detailed examination of the sources of scaling in digital businesses. We propose three mechanisms by which digital business models attempt to gain scale: engaging both non- paying users and paying customers; organizing customer engagement to allow self- customization; and orchestrating networked value chains, such as platforms or multi-sided business models. Scaling conditions are discussed, and propositions developed and illustrated with examples of big data entrepreneurial firms
A new Algorithm Based on Factorization for Heterogeneous Domain Decomposition
Often computational models are too expensive to be solved in the entire
domain of simulation, and a cheaper model would suffice away from the main zone
of interest. We present for the concrete example of an evolution problem of
advection reaction diffusion type a heterogeneous domain decomposition
algorithm which allows us to recover a solution that is very close to the
solution of the fully viscous problem, but solves only an inviscid problem in
parts of the domain. Our new algorithm is based on the factorization of the
underlying differential operator, and we therefore call it factorization
algorithm. We give a detailed error analysis, and show that we can obtain
approximations in the viscous region which are much closer to the viscous
solution in the entire domain of simulation than approximations obtained by
other heterogeneous domain decomposition algorithms from the literature.Comment: 23 page
An introduction to Multitrace Formulations and Associated Domain Decomposition Solvers
Multitrace formulations (MTFs) are based on a decomposition of the problem
domain into subdomains, and thus domain decomposition solvers are of interest.
The fully rigorous mathematical MTF can however be daunting for the
non-specialist. We introduce in this paper MTFs on a simple model problem using
concepts familiar to researchers in domain decomposition. This allows us to get
a new understanding of MTFs and a natural block Jacobi iteration, for which we
determine optimal relaxation parameters. We then show how iterative multitrace
formulation solvers are related to a well known domain decomposition method
called optimal Schwarz method: a method which used Dirichlet to Neumann maps in
the transmission condition. We finally show that the insight gained from the
simple model problem leads to remarkable identities for Calderon projectors and
related operators, and the convergence results and optimal choice of the
relaxation parameter we obtained is independent of the geometry, the space
dimension of the problem{\color{black}, and the precise form of the spatial
elliptic operator, like for optimal Schwarz methods. We illustrate our analysis
with numerical experiments
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