Secure and Efficient Video Transmission in VANET

Currently, vehicular communications have become a reality used by various applications, especially applications that broadcast video in real time. However, the video quality received is penalized by the poor characteristics of the transmission channel (availability, non-stationarity, the ration of signal-to-noise, etc.). To improve and ensure minimum video quality at reception, we propose in this work a mechanism entitled “Secure and Efficient Transmission of Videos in VANET (SETV)”. It's based on the "Quality of Experience (QoE)" and using hierarchical packet management. This last is based on the importance of the images of the stream video. To this end, the use of transmission error correction with uneven error protection has proven to be effective in delivering high quality videos with low network overhead. This is done based on the specific details of video encoding and actual network conditions such as signal to noise ratio, network density, vehicle position and current packet loss rate (PLR) not to mention the prediction of the future DPP.Machine learning models were developed on our work to estimate perceived audio-visual quality. The protocol previously gathers information about its neighbouring vehicles to perform distributed jump reinforcement learning. The simulation results obtained for several types of realistic vehicular scenarios show that our proposed mechanism offers significant improvements in terms of video quality on reception and end-to-end delay compared to conventional schemes. The results prove that the proposed mechanism has showed 11% to 18% improvement in video quality and 9% load gain compared to ShieldHEVC

TACRM: trust access control and resource management mechanism in fog computing

https://hcis-journal.springeropen.com/articles/10.1186/s13673-019-0188-3#Abs1Fog computing network is designed as an extension of the cloud due to the need for a supporting platform capable of ensuring the requirements of Internet of Thing (IoT). The growth of fog based fifth generation mobile communication (5G) system is challenged by the need for data sharing security. In fact, without properly securing access to Fog node resources in IoT network, services providers may not be able to achieve the desired performance. Indeed, fog computing obviously confront numerous security and privacy risks, due to its features, such as huge scale geolocation, heterogeneity and mobility. Thus, we propose a security model that is based on cooperation between IoT and fog. This model integrates an efficient access control process associated with a monitoring scheme to ensure secure cooperation between diverse resources and different operational parts. Indeed, a comprehensive scheduling process and resource allocation mechanism using our security model is proposed to improve the intended performance of the system. In fact, our main contribution is to introduce a distributed access control based on security resource management framework for fog-IoT networks, and proactive security scheme under ultra-trustworthiness and low-latency constraints. After evaluation based on iFogSim, we have proved that our scheme not only provides low latency with high security and privacy, but also reduces the complexity of administration and management of security and resources mechanisms

DVF-fog: Distributed virtual firewall in fog computing based on risk analysis

To eliminate network saturation during data exchanges, fog computing is deployed as the technology that benefits from both cloud computing and internet of things (IoT) paradigms. Therefore, we focus on network access control issues that are considered as grave challenges in a distributed environment such as fog/cloud computing. Therefore, we present an architecture for distributed fog with a divided topology into zones and implement distributed firewall/controller. This way, we can combine user-based access control and distributed network-based access control based on risk analysis and estimation. The simulation results show that our proposed technique improves the network performance in terms of throughput and blocking rate and it is able to prevent DDoS. Furthermore, the comparison with existing approaches based on the openstack framework illustrates that the fog-based distributed virtual firewall (DVF) approach decreases significantly the false positive rate (FPR) to be 0.0942% and increases the true positive rate (TPR) to be 99.9%. 2019 Inderscience Enterprises Ltd.Scopus2-s2.0-8508648485

Influence of Nutrient Gradient on Phytoplankton Size Structure, Primary Production and Carbon Transfer Pathway in a Highly Productive Area (SE Mediterranean)

International audienceWe assessed the spatial variability in the size structure of phytoplankton, community composition, primary production and carbon fluxes through the planktonic food web of the Gulf of Gabès (GG; Southeastern Mediterranean Sea) in the fall of 2017 during the MERMEX-MERITE cruise. High concentrations in nutrients, chlorophyll a (~ 2–6 µg L−1) and primary production (1816–3674 mg C m−2 d−1) revealed an eutrophic status of the studied stations in the GG. In accordance with hydrodynamic features, inorganic nutrients showed increases in concentrations from North to South and from coast to offshore, these nutrient gradients impacting the spatial distribution of phytoplankton community. Size-fractioned phytoplankton biomass and production were the lowest in the northernmost zone where they were mainly sustained by pico-sized fraction. Concomitantly, in this area, small aloricate ciliates were dominant leading to a high microbivory. Conversely, higher biomass and production were measured towards the South and offshore with prevalence of larger phytoplankton (nano- and/or micro-sized fractions) supported by diatoms. The herbivorous protozooplankton and metazooplankton were more abundant in these zones, resulting in an increase of the herbivory. The vertical particulate organic carbon flux followed also a north–south and coast-offshore increasing gradient, with a higher contribution of phytoplankton, and zooplankton fecal pellets to the sinking organic matter in the southernmost area. Our results suggest that even in nutrient-rich and highly productive waters, a continuum of trophic pathways, ranging from microbial to multivorous and herbivorous food webs, may exist, which implies different efficiencies in carbon export and carrying capacity within the ecosystem

Contamination of planktonic food webs in the Mediterranean Sea: Setting the frame for the MERITE-HIPPOCAMPE oceanographic cruise (spring 2019)

International audienceThis paper looks at experiential feedback and the technical and scientific challenges tied to the MERITE-HIPPOCAMPE cruise that took place in the Mediterranean Sea in spring 2019. This cruise proposes an innovative approach to investigate the accumulation and transfer of inorganic and organic contaminants within the planktonic food webs. We present detailed information on how the cruise worked, including 1) the cruise track and sampling stations, 2) the overall strategy, based mainly on the collection of plankton, suspended particles and water at the deep chlorophyll maximum, and the separation of these particles and planktonic organisms into various size fractions, as well as the collection of atmospheric deposition, 3) the operations performed and material used at each station, and 4) the sequence of operations and main parameters analysed. The paper also provides the main environmental conditions that were prevailing during the campaign. Lastly, we present the types of articles produced based on work completed by the cruise that are part of this special issue