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Ghadir Jradi

Publications and source records attributed to Ghadir Jradi.

3 recordsLinked to original sources

A coupled prediction-correction Hughes' model for congested crowd motion

In this work, we introduce a new macroscopic model for crowd motion inspired by the celebrated Hughes' model \cite{Hughes2002, Hughes2003}, which couples a nonlinear conservation law for the pedestrian density with an Eikonal equation describing the shortest path to the target. Our approach can be viewed both as a modification of Hughes' original formulation and as a refinement of the prediction-correction framework proposed in the recent work \cite{ennaji2023prediction}. The resulting model incorporates anticipatory behavior and dynamic route adjustment, offering a more realistic representation of crowd dynamics in complex environments. We present the mathematical formulation of the model, discuss its well-posedness properties, and illustrate its qualitative behavior through numerical simulations. Ultimately, we show, at least from a numerical perspective, that this variant provides a promising avenue towards establishing the well-posedness of the classical Hughes' model, which has remained a challenging open problem for a long time.

math.AP

Congested Crossing Pedestrian Traffic Flow : Dispersion vs. Transport in Crowded Areas

This study investigates the complex dynamic interactions between two typed populations coexisting within a shared space. We propose both theoretical and numerical study to analyze scenarios where one population (population $1$) must traverse a territory occupied by another (population $2$), necessitating strategies to mitigate overcrowding caused by spatial limitations. To capture these interactions, we model population $1$ using a linear transport equation, while population $2$ is described by a granular diffusion model a la sandpile to represent its internal dynamics and tendency to decongest. Through numerical simulations, we explore how different movement strategies of the traversing population (population $1$) - including directed motion towards a specific destination, internal dispersion to minimize crowding, and uniform dispersal across the space - affects the behavior of population $2$.

math.AP

Prediction-Correction Pedestrian Flow by Means of Minimum Flow Problem

We study a new variant of mathematical prediction-correction model for crowd motion. The prediction phase is handled by a transport equation where the vector field is computed via an eikonal equation $\Vert \nablaφ\Vert=f$, with a positive continuous function $f$ connected to the speed of the spontaneous travel. The correction phase is handled by a new version of the minimum flow problem. This model is flexible and can take into account different types of interactions between the agents, from gradient flow in Wassersetin space to granular type dynamics like in sandpile. Furthermore, different boundary conditions can be used, such as non-homogeneous Dirichlet (e.g., outings with different exit-cost penalty) and Neumann boundary conditions (e.g., entrances with different rates). Combining finite volume method for the transport equation and Chambolle-Pock's primal dual algorithm for the eikonal equation and minimum flow problem, we present numerical simulations to demonstrate the behavior in different scenarios.

math.AP