Arabic or Latin: Language Contact and Script Practices

This study discusses the social aspects of script reforms and the hierarchies attached to languages and scripts in contact. In Morocco, Arabic, French, and Berber/Amazigh compete for similar social domains. In recent years, intense debates took place surrounding the official adoption of Tifinagh to codify Amazigh; however less focus has been placed on the unofficial selection of the French-based Latin characters to write both Arabic and Amazigh. This study argues that, besides practicality, preference of the Latin script in Morocco is ideologically connected to the status of French as a language that indexes power, modernity and social prestige

The Energetic Implications of Using Deforming Reference Descriptions to Simulate the Motion of Incompressible, Newtonian Fluids

In this work the issue of whether key energetic properties (nonlinear, exponential-type dissipation in the abscence of forcing and long-term stability under conditions of time dependent loading) are automatically inherited by deforming reference descriptions is resolved. These properties are intrinsic to real flows and the conventional Navier-Stokes equations. A completely general reference description of an incompressible, Newtonian fluid, which reconciles the differences between opposing schools of thought in the literature is derived for the purposes of this investigation. The work subsequently focusses on establishing a class of time discretisations which inherit these self-same energetic properties, irrespective of the time increment employed. The findings of this analysis have profound consequences for the use of certain classes of finite difference schemes in the context of deforming references. It is significant that many algorithms presently in use do not automatically inherit the fundamental qualitative features of the dynamics. An `updated' approach as a means of avoiding ever burgeoning deformation gradients and a still further simplified implementation are further topics explored.Comment: 26 pages, 2 figures, lemma 2 proof correcte

Deep Convolutional Architectures for Extrapolative Forecast in Time-dependent Flow Problems

Physical systems whose dynamics are governed by partial differential equations (PDEs) find applications in numerous fields, from engineering design to weather forecasting. The process of obtaining the solution from such PDEs may be computationally expensive for large-scale and parameterized problems. In this work, deep learning techniques developed especially for time-series forecasts, such as LSTM and TCN, or for spatial-feature extraction such as CNN, are employed to model the system dynamics for advection dominated problems. These models take as input a sequence of high-fidelity vector solutions for consecutive time-steps obtained from the PDEs and forecast the solutions for the subsequent time-steps using auto-regression; thereby reducing the computation time and power needed to obtain such high-fidelity solutions. The models are tested on numerical benchmarks (1D Burgers' equation and Stoker's dam break problem) to assess the long-term prediction accuracy, even outside the training domain (extrapolation). Non-intrusive reduced-order modelling techniques such as deep auto-encoder networks are utilized to compress the high-fidelity snapshots before feeding them as input to the forecasting models in order to reduce the complexity and the required computations in the online and offline stages. Deep ensembles are employed to perform uncertainty quantification of the forecasting models, which provides information about the variance of the predictions as a result of the epistemic uncertainties

QUANTIFICATION ET EVALUATION DE L’EROSION HYDRIQUE EN UTILISANT LE MODÈLE RUSLE ET DÉPOSITION INTÉGRÉS DANS UN SIG. APPLICATION DANS LE BASSIN VERSANT N'FIS DANS LE HAUT ATLAS DE MARRAKECH (MAROC)

Located in the High Atlas central-western, N'Fis basin shows a dissected topography, frequent and violent floods, and its characterization by a litho-stratigraphic succession from the Precambrian to the current that engender significant erosion, and cause reservoirs siltation. This study aims to map areas vulnerable to erosion in the N'Fis Basin, developed a Geographic Information System (GIS) into account soil types, networks of drainage and traffic direction integrating remote sensing and spatial data. The results highlight the hydrographic phenomena and their effects on water resources. To achieve the objective of calculating the RUSLE equation Factor, it was based on annual and monthly climate data, field missions, the digital elevation model and satellite imagery. The result indicates a change in the rate of erosion and the values are between 7t / ha / year downstream of the wadi N'fis and a maximum value 1221t / ha / year to non-arable areas and areas with strong slope values

Potential-field geophysical data inversion for 3D modelling and reserve estimation (Example of the Hajjar mine, Guemassa massif, Morocco): magnetic and gravity data case

Geophysical data inversion is a tool, which can be used to recover the subsurface distribution of physical properties from field data. Each type of geophysical data can be inverted using one or more inversion algorithms. In this paper, a set of geophysical magnetic and gravity data of the Hajjar area in Morocco, covering an extent of $3.2\times 1.6~\mathrm{km}^{2}$, were used to make a 3D model of an orebody and to estimate the mineral reserve by potential-field geophysical data inversion and excess mass estimation. We thus promote the development and application of potential-field geophysical data inversion using the softwares Geosoft Oasis Montaj and Voxi Earth Modelling™ and the evaluation of its power compared to the excess mass estimation method. The process of inversion begins with data processing, then moves to analysis and interpretation, and ends with unconstrained Cartesian cut cell inversion. The results show a variation of $-$0.22 mGal to 1.59 mGal for the gravity residual anomaly map, leading to have density variations from $2.45~\mathrm{g}/\mathrm{cm}^{3}$ to $4.22~\mathrm{g}/\mathrm{cm}^{3}$, and a variation of $-$232 nT to 1018 nT for the reduced magnetic anomaly map.Moreover, data inversion allowed us to create a 3D model of the orebody and of the adjacent geological formation, and to estimate the different parameters that characterize the orebody derived from the inversion results, which have been confirmed from survey data: (depth $\approx 160$ m; maximum density $\approx 4.22~\mathrm{g}/\mathrm{cm}^{3}$; minimum density $\approx 3~\mathrm{g}/\mathrm{cm}^{3}$; mean density $\approx 3.61~\mathrm{g}/\mathrm{cm}^{3}$; thickness of the overburden $\approx$120 m; dip $\approx 45^{\circ }$; morphology ${\approx }$ lens; volume $\approx 4.8 \times 10^{6}~\mathrm{m}^{3}$).It was therefore possible to evaluate the reserve, and to validate the reliability of the inversion by having a root mean square error between the exploited reserve and the calculated reserve of 13.5%, i.e. an insignificant difference between the real and calculated magnetic and gravity orebody responses, which support the validity of the results

On the calculation of normals in free-surface flow problems

The use of boundary-conforming finite element methods is considered for the solution of surface-tension-dominated free-surface flow problems in three dimensions. This class of method is based upon the use of a moving mesh whose velocity is driven by the motion of the free surface, which is in turn determined via a kinematic boundary condition for the normal velocity. The significance of the method used to compute the normal direction at the finite element node points for a C0 piecewise-polynomial free surface is investigated. In particular, it is demonstrated that the concept of mass-consistent normals on an isoparametric quadratic tetrahedral mesh is flawed. In this case an alternative, purely geometric, normal is shown to lead to a far more robust numerical algorithm

Potential-field geophysical data inversion for 3D modelling and reserve estimation (Example of the Hajjar mine, Guemassa massif, Morocco): magnetic and gravity data case

Geophysical data inversion is a tool, which can be used to recover the subsurface distribution of physical properties from field data. Each type of geophysical data can be inverted using one or more inversion algorithms. In this paper, a set of geophysical magnetic and gravity data of the Hajjar area in Morocco, covering an extent of $3.2\times 1.6~\mathrm{km}^{2}$, were used to make a 3D model of an orebody and to estimate the mineral reserve by potential-field geophysical data inversion and excess mass estimation. We thus promote the development and application of potential-field geophysical data inversion using the softwares Geosoft Oasis Montaj and Voxi Earth Modelling™ and the evaluation of its power compared to the excess mass estimation method. The process of inversion begins with data processing, then moves to analysis and interpretation, and ends with unconstrained Cartesian cut cell inversion. The results show a variation of $-$0.22 mGal to 1.59 mGal for the gravity residual anomaly map, leading to have density variations from $2.45~\mathrm{g}/\mathrm{cm}^{3}$ to $4.22~\mathrm{g}/\mathrm{cm}^{3}$, and a variation of $-$232 nT to 1018 nT for the reduced magnetic anomaly map.Moreover, data inversion allowed us to create a 3D model of the orebody and of the adjacent geological formation, and to estimate the different parameters that characterize the orebody derived from the inversion results, which have been confirmed from survey data: (depth $\approx 160$ m; maximum density $\approx 4.22~\mathrm{g}/\mathrm{cm}^{3}$; minimum density $\approx 3~\mathrm{g}/\mathrm{cm}^{3}$; mean density $\approx 3.61~\mathrm{g}/\mathrm{cm}^{3}$; thickness of the overburden $\approx$120 m; dip $\approx 45^{\circ }$; morphology ${\approx }$ lens; volume $\approx 4.8 \times 10^{6}~\mathrm{m}^{3}$).It was therefore possible to evaluate the reserve, and to validate the reliability of the inversion by having a root mean square error between the exploited reserve and the calculated reserve of 13.5%, i.e. an insignificant difference between the real and calculated magnetic and gravity orebody responses, which support the validity of the results

The Upper Neoproterozoic-Lower Cambrian continental extension in the Anti-Atlas (Morocco)

Dans l’Anti-Atlas (sud du Maroc), la couverture du Néo-protérozoïque supérieur, discordante sur les structures panafricaines, s’organise en « séries » volcaniques et détritiques (Groupe du Saghro et de Ouarzazate), recouvertes par les dépôts carbonatés cambriens. De nouvelles observations réalisées dans cette couverture montrent qu’elle résulte d’un épisode extensif dont témoignent, outre les structures extensives, des mises en place de magmas et des manifestations hydrothermales. Cet épisode, qui se maintiendra jusqu’au Cambrien inférieur, est interprété en termes d’extension continentale post-panafricaine

Performance study of plane wave finite element methods with a Padé-type artificial boundary condition in acoustic scattering

International audienceThe aim of this paper is to propose and numerically study the performance of coupling a high-order Pad\'{e}-type non-reflecting boundary condition with plane wave finite element formulations for solving high-frequency scattering problems involving elongated scatterers. It is shown on some numerical examples that the approximate solution can be obtained using a small number of degrees of freedom for a suitable accuracy