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130 results on '"Mhiri, Mariem"'

8. Cross-layer distributed power control: A repeated games formulation to improve the sum energy-efficiency

Author

Mhiri, Mariem, Varma, Vineeth S., Cheikhrouhou, Karim, Lasaulce, Samson, and Samet, Abdelaziz

Subjects
Computer Science - Networking and Internet Architecture, Computer Science - Computer Science and Game Theory, Computer Science - Information Theory
Abstract

The main objective of this work is to improve the energy-efficiency (EE) of a multiple access channel (MAC) system, through power control, in a distributed manner. In contrast with many existing works on energy-efficient power control, which ignore the possible presence of a queue at the transmitter, we consider a new generalized cross-layer EE metric. This approach is relevant when the transmitters have a non-zero energy cost even when the radiated power is zero and takes into account the presence of a finite packet buffer and packet arrival at the transmitter. As the Nash equilibrium (NE) is an energy-inefficient solution, the present work aims at overcoming this deficit by improving the global energy-efficiency. Indeed, as the considered system has multiple agencies each with their own interest, the performance metric reflecting the individual interest of each decision maker is the global energy-efficiency defined then as the sum over individual energy-efficiencies. Repeated games (RG) are investigated through the study of two dynamic games (finite RG and discounted RG), whose equilibrium is defined when introducing a new operating point (OP), Pareto-dominating the NE and relying only on individual channel state information (CSI). Accordingly, closed-form expressions of the minimum number of stages of the game for finite RG (FRG) and the maximum discount factor of the discounted RG (DRG) were established. The cross-layer model in the RG formulation leads to achieving a shorter minimum number of stages in the FRG even for higher number of users. In addition, the social welfare (sum of utilities) in the DRG decreases slightly with the cross-layer model when the number of users increases while it is reduced considerably with the Goodman model. Finally, we show that in real systems with random packet arrivals, the cross-layer power control algorithm outperforms the Goodman algorithm., Comment: 36 pages, single column draft format

Published
2016
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9. A blockchain‐based framework to optimize shipping container flows in the hinterland.

Author

Mhiri, Mariem, Al‐Yafi, Karim, Legros, Benjamin, Jouini, Oualid, and Haouari, Mohamed

Subjects
SHIPPING containers, CONTAINER ships, HINTERLAND, SHIPPING companies, VEHICLE routing problem
Abstract

We address two interrelated issues affecting the hinterland portion of the maritime container supply chain: reducing the movement of empty containers and reducing empty trips by trucks carrying these containers. In this paper, we show that empty container flow optimization can be implemented via a blockchain based on the proof‐of‐useful‐work concept where the proof of work requires the solution of an NP$\mathcal{NP}$‐hard optimization problem whose solution benefits the blockchain participants. Accordingly, we propose that anonymous miners compete to solve the container truck routing problem, which seeks to find the most efficient routes for trucks. We show that this problem is NP$\mathcal{NP}$‐hard. Miners must also solve the problem of optimally matching consignees and shippers, which will reduce transportation and storage costs for empty containers. In essence, the proposed framework turns blockchain into a massive optimization engine that directly benefits the hinterland container supply chain ecosystem. [ABSTRACT FROM AUTHOR]

Published
2024
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12. Energy-Efficient Spectrum Sharing in Relay-Assisted Cognitive Radio Systems

Author

Mhiri, Mariem, Cheikhrouhou, Karim, Samet, Abdelaziz, Mériaux, François, and Lasaulce, Samson

Subjects
Computer Science - Information Theory, Computer Science - Computer Science and Game Theory
Abstract

This work characterizes an important solution concept of a relevant spectrum game. Two energy-efficient sources communicating with their respective destination compete for an extra channel brought by a relay charging the used bandwidth through a pricing mechanism. This game is shown to possess a unique Nash bargaining solution, exploiting a time-sharing argument. This Pareto-efficient solution can be implemented by using a distributed optimization algorithm for which each transmitter uses a simple gradient-type algorithm and alternately updates its spectrum sharing policy. Typical numerical results show to what extent spectral efficiency can be improved in a system involving selfish energy-efficient sources., Comment: IEEE Proc. of the International Conference on Network Games, Control and Optimization (NetGCooP), Nov. 2012, Avignon, France

Published
2013

15. Exact and heuristic approaches for maximizing flows in UAV-enabled wireless cellular networks with multi-hop backhauls

Author

Mhiri, Mariem, Msakni, Mohamed Kais, Hasna, Mazen O., Khattab, Tamer, Haouari, Mohamed, Mhiri, Mariem, Msakni, Mohamed Kais, Hasna, Mazen O., Khattab, Tamer, and Haouari, Mohamed

Abstract

This paper investigates the problem of data routing in backhaul networks using Unmanned Aerial Vehicles (UAVs) to relay data from Small Cells (SCs) to the core network. The objective is to maximize the total fulfilled demand of data to be routed, while ensuring technical requirements such as hop constraints and edge capacity. The problem is formulated using a compact mixed-integer programming model, which can solve small- and medium-sized topologies. In addition, a fast constructive heuristic based on a maximal tree is developed to solve large-scale topologies, resulting in a significant reduction in CPU time. The quality of the heuristic is evaluated by using column generation for solving the linear programming relaxation of an exponential formulation. The computational study shows the effectiveness and value of the proposed compact model and constructive heuristic for various topology sizes. Furthermore, experiments demonstrate that by keeping the network setup constant and updating the demand vector only, the computational time of the compact model can be drastically reduced for all topology sizes.

Published
2024
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41. Association between dementia and vascular disease-associated polymorphisms in a Tunisian population

Author

Rejeb Jihéne, Bouslama Ali, Achour Ons, Ben Rejeb Nabila, Noureddine Mariem, Mhiri Mariem, Ben Amor Sana, Hamdouni Haithem, Benammou Sofien, Omezzine Asma, Naija Salma, and Aounallah Mariam

Subjects
0301 basic medicine, Apolipoprotein E, Oncology, Male, medicine.medical_specialty, Pathology, Tunisia, Peptidyl-Dipeptidase A, 03 medical and health sciences, 0302 clinical medicine, Apolipoproteins E, Risk Factors, Internal medicine, mental disorders, medicine, Dementia, Humans, Vascular Diseases, Allele, Aged, Aged, 80 and over, Polymorphism, Genetic, biology, Vascular disease, business.industry, Aryldialkylphosphatase, General Neuroscience, Haplotype, Angiotensin-converting enzyme, General Medicine, Middle Aged, medicine.disease, PON1, 030104 developmental biology, Etiology, biology.protein, Female, business, 030217 neurology & neurosurgery
Abstract

PURPOSE Dementia is a multifactorial idiopathic pathology caused by clinical, eDementia is a multifactorial idiopathic pathology caused by clinical, environmental and genetic factors. Hence, its etiology is still unknown. We aimed to evaluate the association between five genetic risk factors for vascular diseases and dementia individually and when gathered in haplotypes. MATERIALS AND METHOD We enrolled 200 dementia patients and 300 controls. All subjects were genotyped for vascular diseaseassociated polymorphisms in the genes coding for Apolipoprotein-E (ApoE), angiotensin converting enzyme (ACE) and Paraoxonase-1 (PON1). RESULTS The association between dementia risk and all the studied polymorphisms except of PON1-Q192R was found to be significant. Carrying the ApoE e4 allele seems to increase dementia risk by 4.32 fold (p = 0.001). The risk associated with ACE I and PON1-L55M T alleles were lower (2.58 and 2.11 fold, p < 0.001 and p = 0.015, respectively). When combined in haplotypes, these polymorphisms showed a cumulative and synergetic effect. GTICC haplotype appears to be associated with 9-fold dementia risk (p < 0.001), whereas AADTT seems to reduce dementia risk by 80% (p = 0.003). CONCLUSION Our results suggest that, ApoE e4, ACE I and PON1-L55M T alleles are associated with dementia risk whether these polymorphisms were studied separately or gathered in haplotypes. Still, the contribution of each gene to the pathophysiological development of dementia must be more investigated.

Published
2017

44. Dementia Revealing Multiple Sclerosis

Author

Sakka, Salma, primary, Farhat, Nouha, additional, Bouhamed, Amal, additional, Kacem, Hanen Hadj, additional, Hdiji, Olfa, additional, and Chokri Mhiri, Mariem Damak, additional

Published
2018
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46. La myélite aiguë de l’enfant

Author

Mhiri, Mariem, primary, Klaa, Hedia, additional, Ben Achour, Nadia, additional, Benrhouma, Hanene, additional, Rouissi, Aida, additional, Kraoua, Ichraf, additional, and Turki, Ilhem, additional

Published
2016
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