Hakim Ghazzai

Dr. Hakim Ghazzai


Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 March 2020 in IEEE Access
Verified
Journal Article
Open access
NDNajmeddine Dhieb
Najmeddine Dhieb
HGHakim Ghazzai
Hakim Ghazzai
HBHichem Besbes
Hichem Besbes
YMYehia Massoud
Yehia Massoud
The private insurance sector is recognized as one of the fastest-growing industries. This rapid growth has fueled incredible transformations over the past decade. Nowadays, there exist insurance products for most high-value assets such as vehicles, jewellery, health/life, and homes. Insurance companies are at the forefront in adopting cutting-edge operations, processes, and mathematical models to maximize profit whilst servicing their customers claims. Traditional methods that are exclusively based on human-in-theloop models are very time-consuming and inaccurate. In this paper, we develop a secure and automated insurance system framework that reduces human interaction, secures the insurance activities, alerts and informs about risky customers, detects fraudulent claims, and reduces monetary loss for the insurance sector. After presenting the blockchain-based framework to enable secure transactions and data sharing among different interacting agents within the insurance network, we propose to employ the extreme gradient boosting (XGBoost) machine learning algorithm for the aforementioned insurance services and compare its performances with those of other state-of-the-art algorithms. The obtained results reveal that, when applied to an auto insurance dataset, the XGboost achieves high performance gains compared to other existing learning algorithms. For instance, it reaches 7% higher accuracy compared to decision tree models when detecting fraudulent claims. The obtained results reveal that, when applied to an auto insurance dataset, the XGboost achieves high performance gains compared to other existing learning algorithms. For instance, it reaches 7% higher accuracy compared to decision tree models when detecting fraudulent claims. Furthermore, we propose an online learning solution to automatically deal with real-time updates of the insurance network and we show that it outperforms another online state-of-the-art algorithm. Finally, we combine the developed machine learning modules with the hyperledger fabric composer to implement and emulate the artificial intelligence and blockchain-based framework.

16 January 2019 in IEEE Transactions on Vehicular Technology
Verified
Journal Article
Closed access
MGMahdi Ben Ghorbel
Mahdi Ben Ghorbel
David Rodriguez-DuarteDavid Rodriguez-Duarte
David Rodriguez-Duarte
HGHakim Ghazzai
Hakim Ghazzai
Md. Jahangir HossainMd. Jahangir Hossain
Md. Jahangir Hossain
HMHamid Menouar
Hamid Menouar
Unnamed aerial vehicles (UAVs) or drones have attracted growing interest in the last few years for multiple applications; thanks to their advantages in terms of mobility, easy movement, and flexible positioning. In UAV-based communications, mobility and higher line-of-sight probability represent opportunities for the flying UAVs while the limited battery capacity remains its major challenge. Thus, they can be employed for specific applications where their permanent presence is not mandatory. Data gathering from wireless sensor networks is one of these applications. This paper proposes an energy-efficient solution minimizing the UAV and/or sensors energy consumption while accomplishing a tour to collect data from the spatially distributed wireless sensors. The objective is to determine the positions of the UAV “stops” from which it can collect data from a subset of sensors located in the same neighborhood and find the path that the UAV should follow to complete its data gathering tour in an energy-efficient manner. A non-convex optimization problem is first formulated then, an efficient and low-complex technique is proposed to iteratively achieve a sub-optimal solution. The initial problem is decomposed into three sub-problems: The first sub-problem optimizes the positioning of the stops using linearization. The second one determines the sensors assignment to stops using clustering. Finally, the path among these stops is optimized using the travel salesman problem. Selected numerical results show the behavior of the UAV versus various system parameters and that the achieved energy is considerably reduced compared to the one of existing approaches.

9 March 2015 in IEEE Transactions on Vehicular Technology
Verified
Journal Article
Closed access
HGHakim Ghazzai
Hakim Ghazzai
EYElias Yaacoub
Elias Yaacoub
MAMohamed-Slim Alouini
Mohamed-Slim Alouini
ZDZaher Dawy
Zaher Dawy
AAAdnan Abu-Dayya
Adnan Abu-Dayya
Base station (BS) deployment in cellular networks is one of the fundamental problems in network design. This paper proposes a novel method for the cell planning problem for fourth-generation (4G) cellular networks using metaheuristic algorithms. In this approach, we aim to satisfy both cell coverage and capacity constraints simultaneously by formulating an optimization problem that captures practical planning aspects. The starting point of the planning process is defined through a dimensioning exercise that captures both coverage and capacity constraints. Afterward, we implement a metaheuristic algorithm based on swarm intelligence (e.g., particle swarm optimization or the recently proposed gray-wolf optimizer) to find suboptimal BS locations that satisfy both problem constraints in the area of interest, which can be divided into several subareas with different spatial user densities. Subsequently, an iterative approach is executed to eliminate eventual redundant BSs. We also perform Monte Carlo simulations to study the performance of the proposed scheme and compute the average number of users in outage. Next, the problems of green planning with regard to temporal traffic variation and planning with location constraints due to tight limits on electromagnetic radiations are addressed, using the proposed method. Finally, in our simulation results, we apply our proposed approach for different scenarios with different subareas and user distributions and show that the desired network quality-of-service (QoS) targets are always reached, even for large-scale problems.

11 September 2017 in IEEE Transactions on Green Communications and Networking
Verified
Journal Article
Closed access
HGHakim Ghazzai
Hakim Ghazzai
MGMahdi Ben Ghorbel
Mahdi Ben Ghorbel
AKAbdullah Kadri
Abdullah Kadri
Md. Jahangir HossainMd. Jahangir Hossain
Md. Jahangir Hossain
HMHamid Menouar
Hamid Menouar
Micro unmanned aerial vehicles (MUAVs) have attracted much interest in multiple applications. Most of the MUAV-based applications require time-limited access to the spectrum to complete data transmission due to limited battery capacity of the flying units. These characteristics are the origin of two challenges in MUAV-based communications: 1) efficient-energy management and 2) opportunistic spectrum access. This paper proposes an energy-efficient solution to minimize the MUAV’s flying and communication energies while integrating cognitive radio technology. A non-convex optimization problem exploiting the mobility of MUAVs is developed for the underlay operating mode where the data rate threshold of the spectrum’s owner has to be respected. The objective is to determine a joint optimized 3-D location and transmit power control solution by which the secondary MUAV can complete its transmission. A deterministic algorithm based on the Weber formulation is proposed to solve the optimization problem. The performances of the deterministic approach are compared to those of a meta-heuristic algorithm, namely particle swarm optimization algorithm (PSO). Selected numerical results illustrate the behavior of the MUAV versus various system parameters. It is shown that the proposed solution achieves very close results to those of the PSO in spite of their different conceptional constructions.

18 March 2014 in IEEE Transactions on Vehicular Technology
Verified
Journal Article
Closed access
HGHakim Ghazzai
Hakim Ghazzai
EYElias Yaacoub
Elias Yaacoub
MAMohamed-Slim Alouini
Mohamed-Slim Alouini
AAAdnan Abu-Dayya
Adnan Abu-Dayya
Energy efficiency aspects in cellular networks can contribute significantly to reducing worldwide greenhouse gas emissions. The base station (BS) sleeping strategy has become a well-known technique to achieve energy savings by switching off redundant BSs mainly for lightly loaded networks. Moreover, introducing renewable energy as an alternative power source has become a real challenge among network operators. In this paper, we formulate an optimization problem that aims to maximize the profit of Long-Term Evolution (LTE) cellular operators and to simultaneously minimize the CO2 emissions in green wireless cellular networks without affecting the desired quality of service (QoS). The BS sleeping strategy lends itself to an interesting implementation using several heuristic approaches, such as the genetic (GA) and particle swarm optimization (PSO) algorithms. In this paper, we propose GA-based and PSO-based methods that reduce the energy consumption of BSs by not only shutting down underutilized BSs but by optimizing the amounts of energy procured from different retailers (renewable energy and electricity retailers), as well. A comparison with another previously proposed algorithm is also carried out to evaluate the performance and the computational complexity of the employed methods.

2 February 2024 in IEEE Access
Verified
Journal Article
Open access
SBSihem Baccari
Sihem Baccari
Mohamed HaddedMohamed Hadded
Mohamed Hadded
HGHakim Ghazzai
Hakim Ghazzai
HTHaifa Touati
Haifa Touati
MEMourad Elhadef
Mourad Elhadef
In Intelligent Transportation Systems (ITS), ensuring road safety has paved the way for innovative advancements such as autonomous driving. These self-driving vehicles, with their variety of sensors, harness the potential to minimize human driving errors and enhance transportation efficiency via sophisticated AI modules. However, the reliability of these sensors remains challenging, especially as they can be vulnerable to anomalies resulting from adverse weather, technical issues, and cyber-attacks. Such inconsistencies can lead to imprecise or erroneous navigation decisions for autonomous vehicles that can result in fatal consequences, e.g., failure in recognizing obstacles. This survey delivers a comprehensive review of the latest research on solutions for detecting anomalies in sensor data. After laying the foundation on the workings of the connected and autonomous vehicles, we categorize anomaly detection methods into three groups: statistical, classical machine learning, and deep learning techniques. We provide a qualitative assessment of these methods to underline existing research limitations. We conclude by spotlighting key research questions to enhance the dependability of autonomous driving in forthcoming studies.