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Marina di Pisa, Italy

Caffaz A.,GraalTech | Caiti A.,Universit | Casalino G.,ISME | Turetta A.,University of Genoa
IEEE Robotics and Automation Magazine | Year: 2010

This article reviewed the design development behind the evolution toward the hybrid glider/AUV vehicle Folaga III and also the ongoing progress in terms of vehicle improvement and networking infrastructure development. The discussion of the C & C architecture has highlighted the methodological approach, some benefits and also some drawbacks, as in particular, the presence of a nonnegligible Munk moment effect. The participation in the GLINT'08 experiment has shown that the current version of the vehicle already has operational capacity in terms of oceanographic sampling, autonomous behavior, communication capabilities, endurance, and failure proofness. The experimental data have also shown some vehicle dynamic behaviors that, although not critical for the oceanographic missions, clearly indicate the kind of improvements that still have to be introduced at the lowest control level, via accurate control algorithm redesign. In particular, the presence of the additional actuation mechanism for fine pitch control seems unavoidable if pitch error below few degrees is required. The same also holds for the vehicle diving mode, where the use of the same additional actuation mechanisms has to be studied in conjunction with a substantial refinement in terms of optimal bang-bang control of the annexed ballast control subsystem. © 2006 IEEE.

Mhiri F.,University of Carthage | Mhiri F.,TIME Higher School | Reguiga K.S.B.,University of Carthage | Bouallegue R.,University of Carthage | Pujolle G.,Universit
2011 the 10th IFIP Annual Mediterranean Ad Hoc Networking Workshop, Med-Hoc-Net'2011 | Year: 2011

The femtocell concept is an emerging technology for deploying the next generation of the wireless networks, aiming at increasing capacity and offloading the overlay macrocell traffic. Energy costs account for as much as half of a mobile operator's operating expenses. Thus, finding radio networking solutions that can greatly improve energy-efficiency as well as resource-efficiency (Green Communications) is not only benefit for the global environment but also makes commercial sense for telecommunication operators supporting sustainable and profitable business. In this paper, we propose a green and distributed algorithm to dynamically optimize the coverage of a femtocell group by adjusting their transmitting power in an Administrative Domain. The resulting evolved algorithm shows the ability to optimize the coverage well, and consequently the resultant substantial energy consumption. © 2011 IEEE.

Modeling of CD4 cells counts response was performed through a Non-Hierarchical-descendant process with profoundly immunocompromised symptomatic patients under nevirapine or efavirenz-based antiretroviral regimen in Abidjan. Similar CD4 cells count trajectories have been modelled in meta-trajectories linked to patients' classes. Global immunological response is similar between "nevirapine group" and "efavirenz group" but the model showed an internal variation of this response in each group. In the both groups, some variables presented a significant variation between classes: average CD4, CD4 Nadir, CD4 peak and average gain of CD4. In "nevirapine group", these following parameters vary significantly between classes: mean weight, mean haemoglobin count and mean increase in haemoglobin count and sex. It's also important to note that, all meta-trajectories began with distinctive categories of baseline CD4 cells counts. Other explanatory factors must be sought because the characteristics we have chosen to describe patients'classes, are not exhaustive. © 2011 Société Française de Pharmacologie et de Thérapeutique.

Sethom K.,University of Carthage | Salem A.B.,University of Carthage | Mhiri F.,Universit | Bouallegue R.,University of Carthage
2012 Wireless Advanced, WiAd 2012 | Year: 2012

The LTE femtocell network is an emerging technology for deploying the next generation of wireless networks. One of the most important issues in this new concept is radio resource management such as interference reduction and packet scheduling. This paper proposes a cognitive approach based on modified version of exponential (EXP-rule) and maximum-largest weighted delay first (M-LWDF) scheduling algorithms for long term evolution (LTE) femto-networks. System performance can be improved by adapting to users' needs and memberships inside the network. © 2012 IEEE.

Mhiri F.,University of Carthage | Mhiri F.,TIME Higher School | Sethom K.,University of Carthage | Sethom K.,TIME Higher School | And 3 more authors.
Proceedings of 2012 International Conference on Multimedia Computing and Systems, ICMCS 2012 | Year: 2012

Femtocell is envisioned as a promising solution for indoor wireless communications. Considering that the major cause of interference in OFDMA is that femtocells are installed in an ad-hoc manner; cognitive radios promise to provide the intelligence and flexibility necessary for the success of femtocells. In this paper, we propose a new distributed resource allocation mechanism to deal with the interference between nearby femtocells in Enterprise environments. © 2012 IEEE.

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