Selecting source image sensor nodes based on 2-hop information to improve image transmissions to mobile robot sinks in search \& rescue operations

We consider Robot-assisted Search $\&$ Rescue operations enhanced with some fixed image sensor nodes capable of capturing and sending visual information to a robot sink. In order to increase the performance of image transfer from image sensor nodes to the robot sinks we propose a 2-hop neighborhood information-based cover set selection to determine the most relevant image sensor nodes to activate. Then, in order to be consistent with our proposed approach, a multi-path extension of Greedy Perimeter Stateless Routing (called T-GPSR) wherein routing decisions are also based on 2-hop neighborhood information is proposed. Simulation results show that our proposal reduces packet losses, enabling fast packet delivery and higher visual quality of received images at the robot sink

An Energy Efficient Self-healing Mechanism for Long Life Wireless Sensor Networks

In this paper, we provide an energy efficient self- healing mechanism for Wireless Sensor Networks. The proposed solution is based on our probabilistic sentinel scheme. To reduce energy consumption while maintaining good connectivity between sentinel nodes, we compose our solution on two main concepts, node adaptation and link adaptation. The first algorithm uses node adaptation technique and permits to distributively schedule nodes activities and select a minimum subset of active nodes (sentry) to monitor the interest region. And secondly, we in- troduce a link control algorithm to ensure better connectiv- ity between sentinel nodes while avoiding outliers appearance. Without increasing control messages overhead, performances evaluations show that our solution is scalable with a steady energy consumption. Simulations carried out also show that the proposed mechanism ensures good connectivity between sentry nodes while considerably reducing the total energy spent.Comment: 6 pages, 8 figures. arXiv admin note: text overlap with arXiv:1309.600

Autonomic Management using Self-Stabilization for Hierarchical and Distributed Middleware

International audienceDynamic nature of distributed architecture is a major challenge to avail the benefits of distributed computing. An effective solution to deal with this dynamic nature is to implement a self-adaptive mechanism to sustain the distributed architecture. Self-adaptive systems can autonomously modify their behavior at run-time in response to changes in their environment. This capability may be included in the software systems at design time or later by external mechanisms. Our paper describes the self- adaptive algorithm that we developed for an existing middleware. Once the middleware is deployed, it can detect a set of events which indicate an unstable deployment state. When an event is detected, some instructions are executed to handle the event. We have designed a simulator to have a deeper insights of our proposed self-adaptive algorithm. Results of our simulated experiments validate the safe convergence of the algorithm

Performance comparison of hierarchical checkpoint protocols grid computing

Grid infrastructure is a large set of nodes geographically distributed and connected by a communication. In this context, fault tolerance is a necessity imposed by the distribution that poses a number of problems related to the heterogeneity of hardware, operating systems, networks, middleware, applications, the dynamic resource, the scalability, the lack of common memory, the lack of a common clock, the asynchronous communication between processes. To improve the robustness of supercomputing applications in the presence of failures, many techniques have been developed to provide resistance to these faults of the system. Fault tolerance is intended to allow the system to provide service as specified in spite of occurrences of faults. It appears as an indispensable element in distributed systems. To meet this need, several techniques have been proposed in the literature. We will study the protocols based on rollback recovery. These protocols are classified into two categories: coordinated checkpointing and rollback protocols and log-based independent checkpointing protocols or message logging protocols. However, the performance of a protocol depends on the characteristics of the system, network and applications running. Faced with the constraints of large-scale environments, many of algorithms of the literature showed inadequate. Given an application environment and a system, it is not easy to identify the recovery protocol that is most appropriate for a cluster or hierarchical environment, like grid computing. While some protocols have been used successfully in small scale, they are not suitable for use in large scale. Hence there is a need to implement these protocols in a hierarchical fashion to compare their performance in grid computing. In this paper, we propose hierarchical version of four well-known protocols. We have implemented and compare the performance of these protocols in clusters and grid computing using the Omnet++ simulator

Optimisation de la transmission d'images dans les réseaux de capteurs pour des applications critiques de surveillance

L émergence de petites caméras CMOS et de microphones MEMS, à coût et puissance réduits, a contribué au développement d une technologie permettant la transmission de flux multimédia (audio, image, vidéo) : les réseaux de capteurs multimédia. Cette technologie, offrant de nouvelles perspectives d applications potentielles où la collecte d informations visuelles et/ou acoustiques apporte une plus- value certaine, suscite un intérêt manifeste. Avec des données multimédia, la qualité de service devient désormais une exigence fondamentale pour la transmission dans un environnement contraint en ressources. Dans le contexte spécifique de cette thèse, nous considérons un déploiement par voie aérienne d une grande quantité de capteurs image pour des applications critiques de surveillance telles que la détection d intrusion ou des opérations de recherche et sauvetage. La prise en compte de la criticité des applications constitue un aspect important de cette thèse, novateur par rapport aux contributions déjà effectuées dans le domaine. Nos travaux se fondent sur une méthode d ordonnancement adaptatif de l activité des capteurs image qui fournit, pour chacun d entre eux, son ensemble de cover-sets. La détection d un événement dans le réseau déclenche la transmission d une large quantité d informations visuelles, émanant de plusieurs sources pour résoudre les ambiguïtés. L objectif de cette thèse est d optimiser cette transmission simultanée d images causant des désagréments sur le réseau. Nous avons tout d abord proposé une stratégie de sélection des cover-sets pertinents à activer pour une transmission efficace des images capturées. Cette stratégie, basée sur des critères d état et de voisinage, assure un compromis entre autonomie et criticité. Une extension multi-chemin de GPSR assure la remontée des images émises des sources sélectionnées au puits. Une seconde contribution, également une approche de sélection, se fonde sur les informations de chemins à 2 sauts pour la sélection des cover-sets. Contrairement à la précédente, elle accorde une priorité à la criticité par rapport à la préservation de l énergie, même si cette préservation est faite de manière indirecte. Un protocole de routage multi-chemin T-GPSR essentiellement basé sur les informations à 2 sauts est associé à la seconde approche de sélection. Une étude de performances de la mobilité du puits sur les propositions basées sur les informations à 2 sauts constitue notre troisième contribution.Recent advances of inexpensive and low-power CMOS cameras and MEMS mi- crophones have led to the emergence of Wireless Multimedia Sensor Networks (WMSNs). WMSNs promise a wide spectrum of potential applications which require to ubiquitously capture multimedia content (visual and audio information). To support the transmission of multimedia content in a resource constrained environment, WMSNs may require a certain level of quality of service (QoS) in terms of delay, bandwidth, jitter, reliability, quality level etc. In this thesis, we consider Wireless Image Sensor Networks (WISNs) where sensor nodes equipped with miniaturized visual cameras to provide accurate information in various geographical parts of an area of interest can be thrown in mass for mission-critical applications such as intrusion detection or search & rescue. An innovative and important aspect of this thesis is to take into account the criticality of applications. The network adopts an adaptive scheduling of image sensor node s activity based on the application criticality level, where each node computes its cover-sets. So, event detection triggers the simulataneous transmission of a large volume of visual data from multiples sources to the Sink. The main objective of this thesis is to optimize this simultaneous transmission of images that can degrade network performance. With this goal in mind, we first proposed a multi-criteria approach to select the suitable cover-sets to be activated for reliable transmission of images in mission-critical applications. The proposed approach takes into account various parameters that affect the image quality at the Sink in a multi-hop transmission network and guarantees a compromise between autonomy and criticality. A modified version of GPSR routing protocol supporting the transmission of multimedia streams ensures the transfer of images from selected sources to the Sink. The second contribution consists in an optimized selection strategy based on 2-hop neighborhood information to determine the most relevant cover-sets to be activated to increase reliability for image transmission. This selection approach prioritizes the application s criticality. A multipath extension of GPSR, called T-GPSR, wherein routing decisions are based 2-hop neighborhood information is also proposed. A performance study of the sink mobility on proposals based on 2-hop information is our third contribution.PAU-BU Sciences (644452103) / SudocSudocFranceF

Nature-based One Health approaches to urban agriculture can deliver food and nutrition security

peer reviewedThe increasing global human population is projected to reach 9.7 billion people by 2050. This population growth is currently linked to the trends of world-wide urbanization, growth of megacities and shifting dietary patterns. While humankind faces the daunting challenge of feeding and providing healthy lives for its teeming populations, urban agriculture holds promise for improving the quality of life in cities. Fortunately, policymakers and planners are accepting the need to support urban fringe farmers to increase the resilience of food systems while efficiently managing already strained natural resources. We argue that for urban agriculture to significantly increase food yields, it is crucial to adopt a One Health approach to agriculture and environmental stewardship. Here, we propose six nature-based and climate-smart approaches to accelerate the transition towards more sustainable food systems. These approaches include reducing the reliance on synthetic agricultural inputs, increasing biodiversity through producing locally adapted crops and livestock breeds, using probiotics and postbiotics, and adopting portable digital decision support systems. Such radical approaches to transforming food production will require cross-sectoral stakeholder engagement at international, national, and community levels to protect biodiversity and the environment whilst ensuring sustainable and nutritious diets that are culturally acceptable, accessible, and affordable for all.1. No poverty2. Zero hunger3. Good health and well-being10. Reduced inequalities11. Sustainable cities and communities12. Responsible consumption and production13. Climate action17. Partnerships for the goal

Exclusion mutuelle de groupes dans les systèmes distribués

Group mutual exclusion is an interesting generalization of the mutual exclusion problem. This was introduced by Joung, and some algorithms for the problem have been proposed by incorporating mutual exclusion algorithms. Group mutual exclusion occurs naturally in a situation where a resource can be shared by processes of the same group, but not by processes of different groups. It is also called the "congenial talking philosophers problem".An example of application interesting is a CD jukebox (documentation, films...) on Internet: several users wishing to reach some CD will be able to do it at the same time instead of awaiting the end of the request of the other users. Effective solutions, written in the message passing model and based on the quorums on the one hand and the circulation of token on the other hand are presented in this thesis.We tackle also the problem of the mutual exclusion of group on the ad hoc mobile networks and we have proposed an algorithm which is sensitive to link formation and link breaking and thus which is suitable for ad hoc mobile networks.L'exclusion mutuelle de groupe est une généralisation de l'exclusion mutuelle. Ce problème a été présenté par Joung et quelques algorithmes pour le problème ont été proposés en incorporant ds algorithmes d'exclusion mutuelle. L'exclusion mutuelle de groupe se produit naturellement dans une situation ou une ressource peut être partagée par des processus du même groupe, mais pas par des processus de différents groupes. Il est aussi appelé "problème des philosophes parlant d'une même voix". Un exemple d'application intéressant est un serveur CD (documentation, films...) sur Internet: plusieurs utilisateurs désirant accéder au même CD pourront le faire en même temps au lieu d'attendre la fin de la requête des autres utilisateurs. Des solutions efficaces, écrites dans le modèle à passage de messages et basées sur les quorums d'une part et sur la circulation de jeton d'autre part sont présentées dans cette thèse.Nous abordons aussi le problème de l'exclusion mutuelle de groupe sur les réseaux mobiles ad hoc et nous proposons un algorithme qui est sensible aux formations et coupures de liens et est ainsi approprié pour les réseaux mobiles ad hoc

Exclusion mutuelle de groupe dans les systèmes distribués

L'exclusion mutuelle de groupe est une généralisation intéressante du problème de l'exclusion mutuelle. Ce problème a été présenté par Joung, et quelques algorithmes pour le problème ont été proposés en incorporant des algorithmes d'exclusion mutuelle. L'exclusion mutuelle de groupe se produit naturellement dans une situation où une ressource peut être partagée par des processus du même groupe, mais pas par des processus de différents groupes. Il est aussi appelé problème des philosophes parlant d'une même voix , Un exemple d'application intéressant est un serveur de CD (documentation, films ... ) sur Internet : plusieurs utilisateurs désirant accéder au même CD pourront le faire en même temps au lieu d'attendre la fin de la requête des autres utilisateurs. Des solutions efficaces, écrites dans le modèle à passage de messages et basées sur les quorums d'une part et sur la circulation de jeton d'autre part sont présentées dans cette thèse. Nous abordons aussi le problème de l'exclusion mutuelle de groupe pour les réseaux mobiles ad hoc et nous proposons un algorithme qui est sensible aux formations et coupures de liens et est ainsi approprié pour les réseaux mobiles ad hoc.Group mutual exclusion is an interesting generalization of the mutual exclusion problem. This problem was introduced by Joung, and sorne algorithms for the problem 'have been proposed by incorporating mutual exclusion algorithms. Group mutual exclusion occurs naturally in a situation where a resource can be shared by pro cesses of the same group, but not by pro cesses of different groups. It is also called the congenial talking philosophers problem . An example of application interesting is a CD jukebox (documentation, films ... ) on Internet : several users wishing to reach same CD will be able to do it at the same time instead of awaiting the end of the request of the other users. Effective solutions, written in the message passing model and based on the quorums on the one hand and the circulation of token on the other hand are presented in this thesis. We tackle also the problem of the mutual exclusion of group for the ad hoc mobile networks and we have proposed an algorithm which ~ sensitive to link formation and link breaking and thus which is suitable for ad hoc mobile networks.CERGY PONTOISE-BU Saint-Martin (951272103) / SudocSudocFranceF

Outdoor Localization and Distance Estimation Based on Dynamic RSSI Measurements in LoRa Networks: Application to Cattle Rustling Prevention

International audienc