Fermeture de la communication et information d’expert

L’article suivant s’appuie sur un travail de thèse en cours. Il tente de montrer que les processus de légitimation du discours politique ne s’épuisent pas dans les catégories analytiques définies par Habermas : système et monde vécu. Une expérimentation sur un discours théorique qui, indirectement, renvoie à la question de l’information, assénée ou justifiée, et de la communication au sens le plus noble du terme : la discussion. Avec une évidence sous-jacente : il n’y a de contrepoids à la fermeture du système politique que l’information citoyenne.The following article is based on work for a thesis that is currently being written. It attempts to show that the processes whereby political discourse are legitimised are not exhaustively treated in the analytical categories defined by Habermas: system and the world experienced. This experiment around a theoretical discourse indirectly comes back to the question of information imposed without explanation or justification and communication as discussion, which is the noblest sense of the word. There is an underlying truth: there is no other counterweight to the closing up of the political system than making information available to the citizen

Fundamental Performance Limitations for Average Consensus in Open Multi-Agent Systems

We derive fundamental performance limitations for intrinsic average consensus problems in open multi-agent systems, which are systems subject to frequent arrivals and departures of agents. Each agent holds a value, and the objective of the agents is to collaboratively estimate the average of the values of the agents presently in the system. Algorithms solving such problems in open systems are poised to never converge because of the permanent variations in the composition, size and objective pursued by the agents of the system. We provide lower bounds on the expected Mean Square Error of averaging algorithms in open systems of fixed size. Our derivation is based on the analysis of an algorithm that achieves optimal performance for a given model of replacements. We obtain a general bound that depends on the properties of the model defining the interactions between the agents, and instantiate that result for all-to-one and one-to-one interaction models. A comparison between those bounds and algorithms implementable with those models is then provided to highlight their validity.Comment: 14 pages, 9 figures, submitted to IEEE Transactions on Automatic Contro

Heat Transfer in the Solid Cathode of a Hollow Cathode Plasma Torch

After recalling the working principle of hollow cathode plasma torches, we evaluate the heat flux profile on the cathodic arc root. This evaluation takes into account the physics of the cathode sheath. Particular attention is devoted to electron emission from the cold copper cathode. This heat flux profile is then used as a moving boundary condition to obtain the temperature field in the solid cathode with a heat conduction study, with the aim of discussing the problem of its erosion

Using Salivary Biomarkers for Stress Assessment in Offshore Saturation Diving: A Pilot Study.

Health monitoring during offshore saturation diving is complicated due to restricted access to the divers, the desire to keep invasive procedures to a minimum, and limited opportunity for laboratory work onboard dive support vessels (DSV). In this pilot study, we examined whether measuring salivary biomarkrers in samples collected by the divers themselves might be a feasible approach to environmental stress assessment. Nine saturation divers were trained in the passive drool method for saliva collection and proceeded to collect samples at nine time points before, during, and after an offshore commercial saturation diving campaign. Samples collected within the hyperbaric living chambers were decompressed and stored frozen at -20°C onboard the DSV until they were shipped to land for analysis. Passive drool samples were collected without loss and assayed for a selection of salivary biomarkers: secretory immunoglobulin A (SIgA), C-reactive protein (CRP), tumor necrosis factor (TNF)-α, interleukins IL-6, IL-8, IL-1β, as well as cortisol and alpha-amylase. During the bottom phase of the hyperbaric saturation, SIgA, CRP, TNF-α, IL-8 and IL-1β increased significantly, whereas IL-6, cortisol and alpha-amylase were unchanged. All markers returned to pre-dive levels after the divers were decompressed back to surface pressure. We conclude that salivary biomarker analysis may be a feasible approach to stress assessment in offshore saturation diving. The results of our pilot test are consonant with an activation of the sympathetic nervous system related to systemic inflammation during hyperbaric and hyperoxic saturation. [Abstract copyright: Copyright © 2021 Monnoyer, Lautridou, Deb, Hjelde and Eftedal.