Watermarking for the Secure Transmission of the Key into an Encrypted Image

Ensuring the confidentiality of any data exchanged always presents a great concern for all communication instances. Technically, encryption is the ideal solution for this task. However, this process must deal with the progress of the cryptanalysis that aims to disclose the information exchanged. The risk increases due to the need for a dual transmission that includes the encrypted medium and the decryption key. In a context of chaotic encryption of images, we propose to insert the decryption key into the encrypted image using image watermarking. Thus, only the watermarked encrypted image will be transmitted. Upon reception, the recipient extracts the key and decrypts the image. The cryptosystem proposed is based on an encryption using a dynamic Look-Up Table issued from a chaotic generator. The obtained results prove the efficiency of our method to ensure a secure exchange of images and keys

A new approach to optimise Non-Binary LDPC codes for Coded Modulations

International audienceThis paper is dedicated to the optimisation of Non-Binary LDPC codes when associated to high-order modulations. To be specific, we propose to specify the values of the non-zero NB-LDPC parity matrix coefficients depending on the corresponding check node equation and the Euclidean distance of the coded modulation. In other words, we explore the joint optimisation of the modulation mapping and the non-binary matrix. The performance gains announced by a theoretical analysis based on the Union Bound are confirmed by simulations results. We obtain an 0.2-dB gain in the high SNR regime compared to other state-of-the-art matrices

Formulation and solution of a two-stage capacitated facility location problem with multilevel capacities

In this paper, the multi-product facility location problem in a two-stage supply chain is investigated. In this problem, the locations of depots (distribution centres) need to be determined along with their corresponding capacities. Moreover, the product flows from the plants to depots and onto customers must also be optimised. Here, plants have a production limit whereas potential depots have several possible capacity levels to choose from, which are defined as multilevel capacities. Plants must serve customer demands via depots. Two integer linear programming (ILP) models are introduced to solve the problem in order to minimise the fixed costs of opening depots and transportation costs. In the first model, the depot capacity is based on the maximum number of each product that can be stored whereas in the second one, the capacity is determined by the size (volume) of the depot. For large problems, the models are very difficult to solve using an exact method. Therefore, a matheuristic approach based on an aggregation approach and an exact method (ILP) is proposed in order to solve such problems. The methods are assessed using randomly generated data sets and existing data sets taken from the literature. The solutions obtained from the computational study confirm the effectiveness of the proposed matheuristic approach which outperforms the exact method. In addition, a case study arising from the wind energy sector in the UK is presented

Interdependence between transportation system and power distribution system: a comprehensive review on models and applications

The rapidly increasing penetration of electric vehicles in modern metropolises has been witnessed during the past decade, inspired by financial subsidies as well as public awareness of climate change and environment protection. Integrating charging facilities, especially high-power chargers in fast charging stations, into power distribution systems remarkably alters the traditional load flow pattern, and thus imposes great challenges on the operation of distribution network in which controllable resources are rare. On the other hand, provided with appropriate incentives, the energy storage capability of electric vehicle offers a unique opportunity to facilitate the integration of distributed wind and solar power generation into power distribution system. The above trends call for thorough investigation and research on the interdependence between transportation system and power distribution system. This paper conducts a comprehensive survey on this line of research. The basic models of transportation system and power distribution system are introduced, especially the user equilibrium model, which describes the vehicular flow on each road segment and is not familiar to the readers in power system community. The modelling of interdependence across the two systems is highlighted. Taking into account such interdependence, applications ranging from long-term planning to short-term operation are reviewed with emphasis on comparing the description of traffic-power interdependence. Finally, an outlook of prospective directions and key technologies in future research is summarized.fi=vertaisarvioitu|en=peerReviewed

La gestion communale des déchets en Tunisie. De la transition à la durabilité : le cas de la commune de Sfax

La situation par laquelle est passée la Tunisie depuis la révolution (2011) était si explosive et si fragile qu’elle menaçait l’équilibre du pays et le bien être de la population. L’état de l’environnement en est un indice (détérioration des lieux public, entassement des déchets dans les rues, multiplication des points noirs et des décharges sauvages, pollutions de toutes sortes…). Une telle situation a entrainé un dysfonctionnement social et a incité le citoyen ainsi que les responsables loc..

Développement de nouvelles molécules antibactériennes : pharmacomodulation, synthèse et études biologiques

Antibiotic resistance is one of the most serious threats to global health. The bacterial resistance is increasing rapidly, with a parallel decrease in the discovery of new therapeutic agents. Faced with the urgent need to find new alternatives, in order to limit the spread of resistance in the environment, our project focus on the research and the identification of new molecules for antibacterial purposes. As part of this work, we were particularly interested in the design of series of analogous molecules of bisacodyl, a laxative drug with antibacterial activity. This led us to develop pegylated and amino triarylmethanes. The antibacterial activity of the synthesized compounds was evaluated against Gram (+) and Gram (-) microorganisms. The biocidal activity was also studied against Staphylococcus aureus and Vibrio strains. The biological results obtained allowed us the identification of some structures containing triarylmethane scaffold potentially interesting for antibacterial therapies.Aujourd’hui la résistance aux antibiotiques constitue l’une des plus graves menaces pesant sur la santé mondiale. La résistance bactérienne est en progression rapide avec en parallèle une diminution de la découverte de nouveaux agents thérapeutiques. Face à l’urgence de trouver de nouvelles alternatives, de préserver les médicaments existants et de limiter la progression des résistances dans l’environnement, nous nous sommes orientés au cours de ce projet vers la recherche et l’identification de nouvelles molécules à visée antibactérienne. Dans le cadre de ces travaux nous nous sommes intéressés particulièrement à la conception d’une série de molécules analogues du bisacodyl, un médicament laxatif possédant une activité antibactérienne. Ceci nous a menés à la synthèse de triarylméthanes pégylés et aminés. L’activité antibactérienne des composés synthétisés a été évaluée contre des souches de microorganismes à Gram (+) et à Gram (-). L’activité biocide a été également étudiée contre les souches Staphylococcus aureus et Vibrio. Les résultats biologiques obtenus nous ont permis d’identifier quelques structures contenant le scaffold triarylméthane potentiellement intéressantes pour des thérapies antibactériennes