114,018 research outputs found
Metamodel Instance Generation: A systematic literature review
Modelling and thus metamodelling have become increasingly important in
Software Engineering through the use of Model Driven Engineering. In this paper
we present a systematic literature review of instance generation techniques for
metamodels, i.e. the process of automatically generating models from a given
metamodel. We start by presenting a set of research questions that our review
is intended to answer. We then identify the main topics that are related to
metamodel instance generation techniques, and use these to initiate our
literature search. This search resulted in the identification of 34 key papers
in the area, and each of these is reviewed here and discussed in detail. The
outcome is that we are able to identify a knowledge gap in this field, and we
offer suggestions as to some potential directions for future research.Comment: 25 page
Metamodel-based model conformance and multiview consistency checking
Model-driven development, using languages such as UML and BON, often makes use of multiple diagrams (e.g., class and sequence diagrams) when modeling systems. These diagrams, presenting different views of a system of interest, may be inconsistent. A metamodel provides a unifying framework in which to ensure and check consistency, while at the same time providing the means to distinguish between valid and invalid models, that is, conformance. Two formal specifications of the metamodel for an object-oriented modeling language are presented, and it is shown how to use these specifications for model conformance and multiview consistency checking. Comparisons are made in terms of completeness and the level of automation each provide for checking multiview consistency and model conformance. The lessons learned from applying formal techniques to the problems of metamodeling, model conformance, and multiview consistency checking are summarized
A dynamo driven by zonal jets at the upper surface: Applications to giant planets
We present a dynamo mechanism arising from the presence of barotropically
unstable zonal jet currents in a rotating spherical shell. The shear
instability of the zonal flow develops in the form of a global Rossby mode,
whose azimuthal wavenumber depends on the width of the zonal jets. We obtain
self-sustained magnetic fields at magnetic Reynolds numbers greater than 1000.
We show that the propagation of the Rossby waves is crucial for dynamo action.
The amplitude of the axisymmetric poloidal magnetic field depends on the
wavenumber of the Rossby mode, and hence on the width of the zonal jets. We
discuss the plausibility of this dynamo mechanism for generating the magnetic
field of the giant planets. Our results suggest a possible link between the
topology of the magnetic field and the profile of the zonal winds observed at
the surface of the giant planets. For narrow Jupiter-like jets, the poloidal
magnetic field is dominated by an axial dipole whereas for wide Neptune-like
jets, the axisymmetric poloidal field is weak.Comment: published in Icaru
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