Hicham Lakhlef

Bordeaux INP · ENSEIRB-MATMECA

Human detection plays a pivotal role in many vision-based applications. Effectively detecting humans across diverse environments and situations significantly contributes to enhancing human safety. However, this effectiveness encounters challenges, particularly in hazy conditions that reduce visibility and blur images, thereby impacting the accuracy...

The Internet of Things (IoT) establishes connectivity between billions of heterogeneous devices that provide a variety of essential everyday services. The IoT faces several challenges, including energy efficiency and scalability, that require consideration of enabling technologies such as network softwarization. This technology is an appropriate so...

The Internet of Things (IoT) is an emerging technology that aims to connect heterogeneous and constrained objects to each other and to the Internet. It has grown significantly in a wide variety of applications such as smart homes, smart cities, smart vehicles, etc. The huge number of connected devices increases the challenges, as IoT provides diver...

The passage to a second generation of broadcasting Single Frequency Networks has generated the need for reconfiguring and redesigning existing networks. In this work, we present a robust optimization model for the green design of such networks based on the digital television DVB-T2 standard. Our robust model pursues protection against uncertainty o...

Message collisions and conflicts on the level of communication channels are among the main factors of energy loss problem in large-scale restrained resource wireless networks. Several works addressing message collisions and conflicts has been proposed in the literature. Most of these works propose a centralized approach which is not always suitable...

With the high rate of accidents and crimes around the world, the importance of video surveillance is growing every day and intelligent surveillance systems are being developed to perform surveillance tasks automatically. Detecting human beings accurately in a visual surveillance system is crucial for diverse application areas. The first step in the...

Secure communication is one of the main challenges that are slowing down the development of the Internet of Things (IoT). Key Management (KM) is particularly a difficult security issue, mainly because of the lack of resources of the IoT devices. Most of the existing solutions do not consider the heterogeneous and dynamic nature of the IoT. They do...

Communication collision between devices represents a critical issue in wireless networks. It can cause network disruption, packet loss, communication delay and energy wastage. In the case of mobile networks, collision occurs frequently because of nodes’ mobility. Existing works rely on resolving collision after it happens or use GPS coordinates to...

Medium Access Control (MAC) protocols for wireless decentralized networks in IoT have attracted a lot of attention in both academic and industrial fields. They aim to coordinate access among IoT devices to the shared wireless medium. More specifically, contention-free MAC protocols are known to be more efficient than contention-based ones in the ca...

Internet-of-Things (IoT) refers to the massive network interconnection of objects often equipped with ubiquitous intelligence employed to provide smart services to end users. However, one of the substantial issues of IoT is the limited energy of IoT devices that are expected to run consistently for a long period of time without battery replacement....

Recent advances in emerging technologies have given birth to a new type of networks called Internet of Things (IoT). The emergence of IoT has led practitioners to envision networking a large number of sensors for event monitoring, data collection and filtering. Due to the use of wireless technologies, a secure communication is strongly needed to pr...

The Internet of Things (IoT) is a network that integrates a variety of heterogeneous nodes, such as connected devices (sensors, robots, and smart phones ...), connected cars, smart homes, etc. These smart objects communicate and collaborate in distributed and dynamic environments that are facing several security challenges. Trust management is one...

Because of the introduction and spread of the second generation of the Digital Video Broadcasting—Terrestrial standard (DVB-T2), already active television broadcasters and new broadcasters that have entered in the market will be required to (re)design their networks. This is generating a new interest for effective and efficient DVB optimization sof...

The Internet of Things (IoT) is a network made up of a large number of devices that collaborate to provide various service for the benefit of society. Two communication modes are required to enable a smooth collaboration. A device can send the same message to several other ones participating in the same service. It may also address a specific devic...

This paper considers distributed vertex-coloring in broadcast/receive networks suffering from conflicts and collisions. (A collision occurs when, during the same round, messages are sent to the same process by too many neighbors; a conflict occurs when a process and one of its neighbors broadcast during the same round.) More specifically, the paper...

Internet of Things (IoT) is one of the promising technologies that has attracted a lot of attention in both industrial and academic fields these years. It aims to integrate seamlessly both physical and digital worlds in one single ecosystem that makes up a new intelligent era of Internet. This technology offers a huge business value for organizatio...

Internet of Things (IoT) is a wireless network composed of a variety of heterogeneous objects such as Connected Wearable Devices (sensors, smartwatches, smartphones, PDAs ...), Connected Cars, Connected Homes,...etc. These things use generally wireless communication to interact and cooperate with each other to reach common goals. IoT(. T, n) is a n...

This paper considers the broadcast/receive communication model in which message collisions and message conflicts can occur because processes share frequency bands. (A collision occurs when, during the same round, messages are sent to the same process by too many neighbors. A conflict occurs when a process and one of its neighbors broadcast during t...

Programmable matter i.e. matter that can change its physical properties, more likely its shape according to an internal or an external action is a good example of a cybermatics component. As it links a cyberized shape to real matter, it is a straight example of cyber-physical conjugation. But, this interaction between virtual and real worlds needs...

The vertex coloring problem has received a lot of attention in the context of synchronous round-based systems where, at each round, a process can send a message to all its neighbors, and receive a message from each of them. Hence, this communication model is particularly suited to point-to-point communication channels. Several vertex coloring algor...

This article is on message-passing systems where communication is (a) synchronous and (b) based on the "broadcast/receive" pair of communication operations. "Synchronous" means that time is discrete and appears as a sequence of time slots (or rounds) such that each message is received in the very same round in which it is sent. "Broadcast/receive"...

Microrobots are low-power and low-capacity memory devices that can sense and act. They perform various missions and tasks in a wide range of applications including odor localization, firefighting, medical service, surveillance and security, search and rescue. To achieve these tasks nodes should reconfigure their physical topology to another target...

Wireless sensor networks (WSNs) have a wide range of applications in our lifetime. Indeed, WSNs perform a various missions and tasks in odor localization, firefighting, medical service, surveillance and security. In order to accomplish these tasks, the sensors have to perform partitioning protocols to form an organization into clusters and cliques....

Les microrobots MEMS sont des éléments miniaturisés qui peuvent capter et agir sur l'environnement. Leur taille est de l'ordre du millimètre et ils ont une faible capacité de mémoire et une capacité énergétique limitée. Les microrobots MEMS continuent d'accroître leur présence dans notre vie quotidienne. En effet, ils peuvent effectuer plusieurs mi...

MEMS microrobots are miniaturized electro-mechanical elements, made using the techniques of micro-fabrication. They have limited energy capacity and low memory space. Self-reconfiguration is required for MEMS microrobots to complete their mission and/or to optimize their communication. In this paper, we present a self-reconfiguration protocol from...

Self-reconfiguration for mobile microrobots currently needs a positioning system and a map of the target shape. Traditional positioning solutions, such as GPS or multilateration are not applicable in the micro-world, and maps sharing does not scale. In the literature, if we want a self-reconfiguration of microrobots to a target shape that consists...

In this paper, we propose an improvement of the logical topology by using self-reconfiguration protocol in MEMS microrobot networks. Recently, solutions have been given for this problem for a chain of microrobots as a starting physical topology; the advantage of these solutions is that they are distributed protocols without map of the target shape...

In this paper we propose a distributed and robust parallel redeployment algorithm for MEMS micro robots. MEMS micro robots are low-power and low-memory capacity devices that can sense and act. To deal with the MEMS micro robots characteristics, in this paper, we present an efficient redeployment algorithm without predefined positions of the target...

In this paper we propose a distributed and efficient parallel self-reconfiguration algorithm for MEMS microrobots. MEMS microrobots perform various missions and tasks in a wide range of applications including odor localization, firefighting, medical service, surveillance and security, and search and rescue. To achieve these tasks the self-reconfigu...

In this paper we present a dynamic self reconfiguration protocol for MEMS micro robots. The protocol presented in this paper is without map of the target shape which makes it efficient and scalable. In other words, nodes do not store the positions that build the target shape. Consequently, memory usage for each node is reduced to a constant complex...

The hierarchical clustering for wireless sensors networks is treated to solve the scalability problem in routing protocols for multi-hop wireless networks. Also a clustering-based technique is proposed to provide location management of devices for QoS support. To the best of our knowledge there is no protocol that combines the hierarchical partitio...

MEMS micro robots are low-power and low memory capacity devices that can sense and act. One of the most challenges in MEMS micro robot applications is the self-reconfiguration, especially when the efficiency and the scalability of the algorithm are required. In the literature, if we want a self-reconfiguration of micro robots to a target shape cons...

MEMS microrobots are low-power and low-memory capacity devices that can sense and act. One of the most difficult challenges in MEMS microrobot applications is the self-reconfiguration, especially when the efficiency, parallelism and the scalability of the algorithm are required. Self-reconfiguration with shared map does not scale. Because the map (...

Self-reconfiguration for moving MEMS microrobots currently needs a positioning system and a map of the target shape. Traditional positioning solutions like GPS or multilateration are not applicable in the micro-world and maps sharing does not scale. In this paper we present self-reconfiguration method where nodes are unaware of their positions, and...

Cooperative and distributed relocation strategy of multi-robot systems is a critical matter in self-reconfigurable modular robotic systems. In this paper, we depict a flexible distributed redeployment algorithm to relocate a large collection of micro-robots according to a list of desired final positions. Our algorithm is based on novel mechanisms r...

A wireless sensors network (WSN for short) can be represented as a graph, tree, or other structures. The structure is more or less important depending on the problem that we will deal with and the respect of constraints on WSNs. WSN (p, n) is a wireless sensor network of p stations with n items saved on it. In this paper we are interested in the pe...