Fly-By-Wireless for Next Generation Aircraft: Challenges and Potential solutions

”Fly-By-Wireless” paradigm based on wireless connectivity in aircraft has the potential to improve efficiency and flexibility, while reducing weight, fuel consumption and maintenance costs. In this paper, first, the opportunities and challenges for wireless technologies in safety-critical avionics context are discussed. Then, the assessment of such technologies versus avionics requirements is provided in order to select the most appropriate one for a wireless aircraft application. As a result, the design of a Wireless Avionics Network based on Ultra WideBand technology is investigated, considering the issues of determinism, reliability and security

Performance analysis of TDMA-based Wireless Network for Safety-critical Avionics

The opportunities and challenges for using wireless interconnects for safety-critical avionics have been discussed in our previous work.A Wireless Avionics Network (WAN)has been proposed based on hybrid architecture UWB and Switched Ethernet with adequate reliability and security mechanisms to increase scalability and reduce electromagnetic susceptibility. Furthermore, a TDMA-based protocol was considered to guarantee a contention free access and enhance communication predictability. However, the use of wireless technologies may increase the communication latencies due to transmission errors, and real time constraints have to be verified. In order to deal with the worst case performance analysis of such network, an appropriate schedulability analysis based on Network Calculus formalism is presented in this paper and obtained results for a realistic case study are discussed herein

Design of Low Cost PC-based Simulators for Education and Training Purpose Using DDS

Abstract-The use of simulation in training and education enables to prepare personal in realistic environment. But the cost and the complexity to create and reuse simulations often limits their application. In this paper we investigate a low cost and high fidelity PC-based simulator based on Data Distribution Service (DDS) middleware. The main parts of the systems and the architecture, including the hardware and the software are introduced. Real-time networking between distributed simulators is achieved using a reliable distributed communication, which employs publish-subscribe middleware build using OMG-DDS. Result shows these methods could produce low cost, extensible, reliable and distributed simulators

Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe

Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies

There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity

Evaluation of ad-hoc and mobility architectures using satellite communications

International audienceIn military or emergency scenarios (like Disaster Relief), the area where the terrestrial forces are located is not always easy to cover. In such an area, no infrastructure is available (never deployed or unavailable due to disaster for instance), persons are located in many locations, eventually structured in groups, but distant from one to another. The topology may also introduce difficulties (canyons, mountains, vegetation...). In such scenarios, communications in a group may be done using ad-hoc networks principle, but the communications from one group to another can be compared to the interconnection of ad-hoc networks. We propose in this paper to interconnect these terrestrial ad-hoc networks with a geostationary DVB-RCS system. This satellite network allows us not only to interconnect the groups, but also to provide them with an access to a very far headquarters and also to the Internet, thanks to the bidirectional link supported by these satellite systems. DVB-S/RCS systems, mobility protocols and ad-hoc network protocols are first presented separately. The global architecture is then defined. Each kind of architecture is evaluated alone. Finally, architectures performances are compared to each other and the results are discussed as a conclusion

Analyse des politiques publiques et problématisation du changement dans les politiques régionales de formation professionnelle

Cette synthèse vise à proposer une lecture du changement dans les politiques régionales de formation professionnelle. Dans une première partie, on propose une lecture diachronique des transformations induites par la décentralisation de la formation professionnelle aux conseils régionaux, en insistant sur le rôle stratégique de la production de connaissance sur les territoires, les branches économiques et les trajectoires individuelles. Dans une seconde partie, on développe un modèle d’analyse du changement qui croise comme variables d’analyse les composantes classiques d’une politique publique (représentations, acteurs, instruments) et les lignes de force du changement à l’œuvre au sein du domaine d’action publique que représente la formation professionnelle. Ces lignes de force se structurent sous l’effet d’un répertoire de légitimation qui place la dimension de la proximité au cœur du changement induit par la territorialisation. Ce modèle d’analyse vise à permettre la mise en évidence de la diffusion du changement dans un champ d’action publique donné et propose des pistes pour approfondir sa mesure par l’analyse de son intensité. Pour illustrer ce dernier point, on développe une étude rapide des effets de la mise en œuvre d’un instrument technique, le Nouveau Code des Marchés Publics (NCMP)

Analyse des politiques publiques et problématisation du changement dans les politiques régionales de formation professionnelle

Cette synthèse vise à proposer une lecture du changement dans les politiques régionales de formation professionnelle. Dans une première partie, on propose une lecture diachronique des transformations induites par la décentralisation de la formation professionnelle aux conseils régionaux, en insistant sur le rôle stratégique de la production de connaissance sur les territoires, les branches économiques et les trajectoires individuelles. Dans une seconde partie, on développe un modèle d’analyse du changement qui croise comme variables d’analyse les composantes classiques d’une politique publique (représentations, acteurs, instruments) et les lignes de force du changement à l’œuvre au sein du domaine d’action publique que représente la formation professionnelle. Ces lignes de force se structurent sous l’effet d’un répertoire de légitimation qui place la dimension de la proximité au cœur du changement induit par la territorialisation. Ce modèle d’analyse vise à permettre la mise en évidence de la diffusion du changement dans un champ d’action publique donné et propose des pistes pour approfondir sa mesure par l’analyse de son intensité. Pour illustrer ce dernier point, on développe une étude rapide des effets de la mise en œuvre d’un instrument technique, le Nouveau Code des Marchés Publics (NCMP)