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Casablanca, Morocco

Boujena S.,MACS Laboratory | El Guarmah E.M.,Ecole Royale de lAir | Gouasnouane O.,MACS Laboratory | Pousin J.,INSA Lyon
Proceedings of 2013 International Conference on Industrial Engineering and Systems Management, IEEE - IESM 2013 | Year: 2013

In the process of image restoration, the denoising is an important step. Several models of non-linear diffusive filters requiring solving partial differential equations have been proposed in the literature [1], [2], [3], [4], [5], [6], [7] during the last decades. The existence and uniqueness of a solution in Hilbert space has been established under suitable conditions on the filtering function for the Perona Malik model [5] considering Dirichlet homogeneous and inhomogeneous boundary conditions [1], [2]. In this work, we propose a nonlinear diffusion model inspired by the Perona-Malik one taking into account the Neumann boundary condition. The existence, uniqueness and regularity of the solution to the mathematical problem are established in a Hilbert space. The numerical simulation of the discretized problem is performed using the finite elements method. The effectiveness of this model has been tested on many noisy images with noises of different natures. A comparison of signal to noise ratio (SNR) is used to estimate the quality of the restored images by this model and the Perona-Malik one. © 2013 International Institute for Innovation, Industrial Engineering and Entrepreneurship - I4e2.

Benamar M.,MACS Laboratory | Ahnana S.,MACS Laboratory | Saiyari F.Z.,MACS Laboratory | Benamar N.,MACS Laboratory | And 2 more authors.
Journal of Mobile Multimedia | Year: 2014

Vehicular Delay Tolerant Networks (VDTN) are growing challenging field of Delay Tolerant Networks (DTN) containing mobile nodes (vehicles) that communicate using the paradigm of store carry and forward. In this model, nodes store the bundle waiting for the opportunity to transfer it to another node in the same transmission range, and in a limited duration. VDTN enables communications in a sparse network characterized by low density, high mobility of nodes, intermittent connectivity, no end-to-end communication and no information on the path of nodes, which make routing in such cases difficult and challenging. This paper studies the performances of some well-known VDTN routing protocols in sparse and dense traffic. The proposed scenario considers stationary nodes representing sensors measuring different types of data to be transferred to stationary destination nodes through the VDTN network (vehicles). The destination nodes are the only part of the network that is connected to the Internet. The transmission of collected data is also made by fixed nodes representing stationary relays such as audiosignal traffic lights, placed in the crossroads of Rennes city streets. The map of Rennes has been used and the position of the stoplights has been carried out using Open Data. The aim of our simulation is to study the impact of mobile nodes and stationary relays on the routing protocols performances in dense and sparse traffic. © Rinton Press.

Benamar N.,MACS Laboratory | Benamar M.,MACS Laboratory | Ahnana S.,MACS Laboratory | Saiyari F.Z.,MACS Laboratory | And 2 more authors.
Journal of Theoretical and Applied Information Technology | Year: 2013

Vehicular Delay-Tolerant Networks (VDTNs) are composed of mobile nodes (vehicles) that communicate wirelessly to transfer data between nodes despite connectivity issues. It enables network connectivity in sparse or partitioned opportunistic networks, characterized by the low node density where the vehicular traffic is sparse and direct end-to-end paths between communicating parties do not always exist. Routing in such environments is challenging due to the absence, for nodes, of information about the state of the partitioned network, and because transfer opportunities between nodes are of limited duration. This paper focuses on the study of the performance of some well-known VDTN routing protocols in different scenarios to assess their suitability of use in the case of collecting sensor data in cities. In this paper we study the case of stationary nodes that represent urban sensor measuring different types of data, and transmitting collected information to stationary destination nodes, which are connected to the Internet. The transmission mechanism is performed through a set of mobile nodes in a VDTN context. We study the impact of different parameters on the routing protocols performances, using a large set of simulations and two scenarios. The results show that there is no perfect routing protocolthat is the best for all scenarios. © 2005 - 2013 JATIT & LLS. All rights reserved.

Boutoulout A.,MACS Laboratory | Bourray H.,MACS Laboratory | Alaoui F.Z.El.,MACS Laboratory | Benhadid S.,MMS Laboratory
International Journal of Control | Year: 2014

The objective of this paper is to study the notion of regional observability of hyperbolic semilinear systems. For the state reconstruction in a given subregion, we give a first approach which combines the extension of the HUM method and the fixed point techniques. The analytical case is then explored using sectorial property of the considered dynamic operator and converted to a fixed point problem. The two approaches lead to algorithms which are successfully implemented numerically and illustrated with examples and simulations. © 2014 © 2014 Taylor & Francis.

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