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Rabat, Morocco

Rees D.A.S.,University of Bath | Mojtabi A.,INPT
Transport in Porous Media | Year: 2011

We consider convection in a uniform fluid-saturated porous layer which is bounded by conducting plates and heated from below. The primary aim is to determine the identity of the postcritical convection planform as a function of the thicknesses and conductivities of the bounding plates relative to that of the porous layer. This work complements and extends an early paper by Riahi (J Fluid Mech 129:153-171, 1983) who considered a situation where the porous layer is bounded by infinitely thick conducting media. We present regions in parameter space wherein convection in the form of rolls is unstable and within which cells with square planform form the preferred pattern. © 2011 Springer Science+Business Media B.V.

Jabi M.,INRS EMT | Szczecinski L.,INRS EMT | Benjillali M.,INPT
IEEE Communications Letters | Year: 2012

We propose a simple and accurate approximation of the outage probability at the output of L-branch diversity combining receivers with arbitrarily fading channels. The method is based on the saddlepoint approximation, which only requires the knowledge of the moment generating functions of the signal-to-noise ratio at the output of each diversity branch. In many particular cases of practical interest, the outage approximation is obtained in closed-form expressions. Numerical results illustrate the accuracy of the proposed method for practical outage values in a variety of fading scenarios. © 2012 IEEE.

Hyadi A.,King Abdullah University of Science and Technology | Benjillali M.,INPT | Alouini M.-S.,King Abdullah University of Science and Technology | Da Costa D.B.,Federal University of Ceara
IEEE Transactions on Wireless Communications | Year: 2013

Multihop relaying is an efficient strategy to improve the connectivity and extend the coverage area of secondary networks in underlay cognitive systems. In this work, we provide a comprehensive performance study of cognitive multihop regenerative relaying systems in an underlay spectrum sharing scenario with the presence of multiple primary receivers. Both interference power and peak power constraints are taken into account. In our analysis, all the links are subject to independent, non-identically distributed Nakagami-m fading. We derive closed-form expressions for the outage probability, high-order amount of fading, bit error rate, symbol error rate, and ergodic capacity. Different scenarios are presented to illustrate the obtained results and Monte Carlo simulations confirm the accuracy of our analytical derivations. © 2013 IEEE.

Bahja F.,Laboratoire LRIT Unite Associee Au CNRST | Ibn Elhaj E.H.,INPT | Di Martino J.,University of Lorraine
Proceedings of 2012 International Conference on Multimedia Computing and Systems, ICMCS 2012 | Year: 2012

In the current paper, we propose a new pitch tracking technique based on a wavelet transform in the temporal domain. Our algorithm is designed to determine the pitch frequency of the speech signal using a simple voicing decision algorithm. The pitch period is extracted from the cepstrum excitation signal processed by a wavelet transform; then the pitch contour is refined by thresholding and correction algorithms without any post-processing. The results obtained show that the proposed algorithm provides very good pitch contours compared to those furnished by the Bagshaw database. © 2012 IEEE.

Barth D.,University of Versailles | Echabbi L.,INPT | Hamlaoui C.,Orange S.A.
Telecommunication Systems | Year: 2013

Some interdomain traffic needs specific guarantees in terms of QoS. Hence, an end-to-end QoS provisioning should be maintained by transit Autonomous Systems and final destinations proposing the services. We propose a distributed stock model following a reverse cascade negotiation in order to enable QoS provisioning at the interdomain level. We analyze different stock strategies on a simple network topology using game theory framework and validate our results by simulation. © 2011 Springer Science+Business Media, LLC.

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