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Identifier les Protocoles de Sécurité et Révéler les Vulnérabilités dans les Systèmes de Transmission ERTMS/ETCS
No full textNational audienceThe modernization of railway systems with the introduction of autonomous trains and digitalization has revolutionized transportation, significantly enhancing connectivity and efficiency. However, this advancement has also exposed the railway network to a multitude of cybersecurity threats. Unlike other sectors, the railway industry was initially designed without considering cybersecurity measures, leaving it particularly susceptible to such risks. As connectivity becomes increasingly essential for improving services, the prevalence of cyberthreats poses significant safety concerns for the industry. This article delves into a comprehensive investigation of the safety and security mechanisms deployed to mitigate cyber threats within the railway sector. Specifically, the focus is on understanding the vulnerabilities inherent in the ERTMS/ETCS transmission system and the potential impact on overall system safety if exploited by malicious actors. By proposing cyberattack scenarios targeting the ERTMS/ETCS signalling system, this study aims to shed light on the critical cybersecurity challenges confronting modern railway networks.La modernisation des systèmes ferroviaires avec l'introduction de trains autonomes et la digitalisation a révolutionné le transport, améliorant considérablement la connectivité et l'efficacité. Cependant, ces évolutions ont également exposé le réseau ferroviaire à une multitude de menaces en matière de cybersécurité. Contrairement à d'autres secteurs, l'industrie ferroviaire a été initialement conçue sans prendre en compte les mesures de cybersécurité, laissant celle-ci particulièrement vulnérable à de tels risques. Alors que la connectivité devient de plus en plus essentielle pour améliorer les services, la prévalence des cybermenaces pose des préoccupations majeures en matière de sécurité (safety) pour l'industrie. Cet article explore une investigation complète des mécanismes de sécurité (security et safety) déployés pour atténuer les menaces cybernétiques au sein du secteur ferroviaire. Plus précisément, l'accent est mis sur la compréhension des vulnérabilités inhérentes au système de transmission ERTMS/ETCS et l'impact potentiel sur la sécurité (safety) globale du système en cas d'exploitation par des acteurs malveillants. En proposant des scénarios d'attaques réalistique ciblant le système de signalisation ERTMS/ETCS, cette étude vise à mettre en lumière les défis critiques en matière de cybersécurité auxquels sont confrontés les réseaux ferroviaires modernes
Littérature électronique et diversité bioculturelle : BABEL RËVOLUTION, un projet de recherche-création hétérolingue
No full textInternational audienceBⱯBEL RËVOLUㅏION (https://babel.utc.fr/) is a creative project developed by a multidisciplinary team and inspired by a research question about the link between biodiversity and linguistic and cultural diversity. In a movement between scholarly imaginaries and writing practices, this creative practice-based research project has led to the development of a rhizomatic online participatory narrative. The first part of this paper presents the theoretical framework that informed the project, at the crossroads of sociolinguistics, didactic plurilingualism, and environmental issues. The second part presents the design and development process of BⱯBEL RËVOLUㅏION. The work seeks to create a space conducive to the emergence of a participatory narrative by bringing into contact languages and cultures, social and biological aspects, with an aim that is at once literary, scientific, and pedagogical.BⱯBEL RËVOLUㅏION (https://new.babel-revolution.fr/) é um projeto criativodesenvolvido por uma equipa multidisciplinar e inspirado por uma questão deinvestigação sobre a ligação entre biodiversidade e diversidade linguística e cultural. Num movimento entre imaginários académicos e práticas de escrita, este projeto de investigação baseado em práticas criativas conduziu ao desenvolvimento de uma obra rizomática participativa em linha. A primeira parte deste artigo apresenta o quadro teórico que inspirou o projeto, no cruzamento da sociolinguística, do plurilinguismo literário e didático e das questões ambientais. A segunda parte analisa obras digitais que tratam de questões semelhantes, enquanto a terceira apresenta o processo de conceção e desenvolvimento de BⱯBEL RËVOLUㅏION. A obra procura criar um espaço propício à emergência de uma narrativa contributiva, pondo em contacto línguas e culturas, aspectos sociais e biológicos, com um objetivo simultaneamente literário, científico e pedagógico.BⱯBEL RËVOLUㅏION (https://babel.utc.fr/) est un projet créatif développé par une équipe pluridisciplinaire, questionnant le lien entre biodiversité écologique et diversité linguistique et culturelle. Oscillant entre imaginaires savants et pratiques d'écriture, ce projet de recherche basé sur des pratiques créatives a conduit à l'élaboration d'un récit participatif rhizomatique en ligne, sous forme de graphe. La première partie de cet article présente le cadre théorique qui a nourri le projet, à la croisée de la sociolinguistique, du plurilinguisme didactique et des enjeux environnementaux. La deuxième partie présente le processus de conception et de développement de BⱯBEL RËVOLUㅏION. L'oeuvre cherche à créer un espace propice à l'émergence d'un récit participatif en mettant en contact langues et cultures, dans une démarche sociobiographique, à des fins à la fois littéraires, scientifiques et pédagogiques
Optimization of Bioactive Compound Extraction from Iranian Brown Macroalgae Nizimuddinia zanardini with Ultrasound and Microwave Methods Using Fuzzy Logic
No full textInternational audienceIn this study, three extraction methods of bioactive compounds from the brown algae Nizimuddinia zanardini were ranked using the fuzzy weighting system in two stages, ranking between different conditions and choosing the optimal conditions for each extraction method separately. The inputs included extraction yield (EY), antioxidant activity (DPPH), total flavonoid content (TFC), total phenolic content (TPC), total phlorotannin content (TPhC), time, temperature, power, and cost. The top ranks of the first phase output included: Maceration Extraction (ME) with a score of 52.67, Ultrasound-Assisted Extraction (UAE) with a score of 54.31, and Microwave-Assisted Extraction (MAE) with a score of 73.09. The results of the second stage indicated that the lowest and highest extraction yields were obtained using UAE and MAE, respectively. The TFC in the UAE was determined as 103.29 mg QE (Quercetin Equivalent)/g as the lowest value and, in the ME, 140.95 mg QE/g was the highest value. The highest and lowest TPC and TPhC were observed with MAE and UAE, respectively. DPPH decreased in UAE, MAE, and ME, respectively. According to the fuzzy weighted results and considering the purpose of extraction, MAE can be introduced as the optimal method for extracting bioactive compounds from N. zanardini. The findings on extraction methods underscore the potential to reduce costs and improve the yields of bioactive compounds, such as antioxidants and polyphenols, thereby enhancing the economic viability of functional foods and nutraceuticals
Lignin-functionalized cobalt for catalytic reductive degradation of organic dyes in simple and hybrid binary systems
No full textInternational audienceTo fulfill the unprecedented valorization approaches for lignocellulose, this work focuses on the potential of lignin-derived catalytic systems for bio-remediation, which are natural materials perceived to address the increased demand for eco-conscious catalyzed processes. A useful lignin-functionalized cobalt (Lig-Co) catalyst has been prepared, well-characterized and deployed for the catalyzed reducing decomposition of stable harmful organic pollutants such as methylene blue (MB) and methyl orange (MO), in simple and binary systems. The multifunctional character of lignin and the presence of various active sites can promote effectively loaded metal nanoparticles (NPs). Considerably, optimizing detoxification tests showed that the uncatalyzed use of NaBH4 as a reductive agent led to an incomplete reduction of organic contaminants over a long period of up to 65 min. Interestingly, Lig-Co catalyst exhibited a high reduction rate and turnover frequency of up to 99.23% and 24.12 min−1 for MB, respectively, while they reached 99.25% and 26.21 min−1 for MO at normal temperature. Kinetically quick catalytic reaction was also demonstrated for the hybrid system, in which the rate constant k was 0.175 s−1 and 0.165 s−1 for MB and MO, respectively, within a distinctly low reaction time of around 120 s. The reproducibility of the Lig-Co catalyst induces a desirable capacity to reduce stable dyes present simultaneously in the binary system, with 6 successive catalytic runs and over 80% of activity retained. Such robust findings underline the considerable interest in developing future lignin-mediated catalytic transformations and upscaling biomass-derived products, to meet the growing demand for sustainable and eco-friendly alternatives in various industries
Optimizing Energy Consumption for IoT Adaptive Security: A Mobility-Based Solution
No full textInternational audienceThe Internet of Things (IoT) is transforming communication among devices. The prevalent use of IoT in mobile scenarios introduces vulnerability to attacks, which requires robust security mechanisms. However, the heterogeneity of IoT devices results in diverse security requirements, compounded by varying threat levels across geographical zones. To address this issue, adaptive security solutions that tailor defense mechanisms to the contextual environment (i.e the security requirement of devices and threat level of the environment) are proposed. However, when the threat level increases, the defense mechanism complexity increases. This leads to higher energy consumption and consequently, device failure. To tackle this challenge, we propose in this paper a mobility-based solution to optimize the energy consumption resulting from using adaptive security solutions. Our approach considers the remaining energy of IoT devices, their security requirement and the threat level of the zone in the decision-making process. This task is carried out by an agent trained with Deep Reinforcement Learning. The proposed solution includes Software-Defined Networking and fog computing in order to ensure seamless execution of the security service while the IoT device moves
Anticorps biomimétiques à base de polymères à empreinte moléculaire : outils de diagnostic innovants pour l’insuffisance rénale aigüe
No full textAcute kidney injury (AKI) is a major public health problem, characterized by a rapid and abrupt decline in renal function, occurring in 15% of in-hospital patients and up to 60% of patients in intensive care units. The kidneys lose their ability to properly filter blood, causing waste products and fluids to accumulate in the body, leading to kidney failure, cardiovascular events and other vital organs’ dysfunctions, and eventually to death. To this day, AKI has been challenging to diagnose, as clinical signs might be unobserved or entirely absent, delaying its detection and treatment. It was recently shown that the outcome of AKI is determined by the ability of the kidney to cope with decreased energetic resources and preservation of a mitochondrial function, which is associated with the expression of the stress protein NUPR1 (Nuclear Protein 1), and the urinary quinolinate (QA)/tryptophan (Trp) (uQA/Trp) ratio, respectively. Indeed, an increased urinary QA level (~50 and ~20 μM for AKI patients and healthy persons, respectively) which leads to an increased uQA/Trp (~2.5/~1:AKI/healthy), was quantitatively associated with an increased risk of developing AKI. NUPR1 is an energy-saving factor, protecting renal epithelial cells from cell death. Its presence confers increased resistance to renal aggression during the acute phase of AKI and therefore presents a therapeutic opportunity. However, there is currently no standardized method for detecting the NUPR1 protein in tissues, due to the lack of available and reliable antibodies. The objective of this PhD is to apply molecularly imprinted polymers (MIPs), also known as antibody mimics, to (i) monitor the renal metabolic status by measuring QA and Trp, so as to be able to predict response to treatment and (ii) develop new therapeutic approaches for cell bioimaging of NUPR1 and eventually for stabilizing NUPR1 for its controlled administration, during AKI. For the first objective, MIPs endowed with fluorescent reporter monomers were developed to detect and quantify the renal disease markers, QA and Trp in urine. The MIPs were synthesized in situ on evanescent wave optical fibers; sensing of QA and Trp by fluorescence spectroscopy was rapid and sensitive. In the second part of the PhD, monodispersed MIP nanogels (MIP-NGs) targeting NUPR1 with high affinity (Kd : 18 nM) and selectivity, were synthesized. Preliminary bioimaging applications on human kidney cells expressing NUPR1 showed that fluorescent MIP-NGs recognized NUPR1, present around and in the cell nuclei. Overall, these results pave the way to the project's long-term perspective, which is to develop a functional medical bioanalysis system for use in both biology laboratories and at patient's bedside, for dynamic diagnosis and monitoring of AKI.L'insuffisance rénale aigüe (IRA) est un problème de santé publique majeur, caractérisé par un déclin rapide et brutal de la fonction rénale, survenant chez 15 % des patients hospitalisés et jusqu'à 60 % des patients en unités de soins intensifs. Les reins perdent leur capacité à filtrer correctement le sang, ce qui conduit à une accumulation de déchets et de liquides dans le corps, entraînant une défaillance rénale, des problèmes cardiovasculaires, des dysfonctionnements de certains organes vitaux, et éventuellement la mort. À ce jour, l’IRA est difficile à diagnostiquer, car les signes cliniques sont souvent inaperçus ou totalement absents, retardant ainsi sa détection et son traitement. Il a été récemment démontré que l'évolution de l'IRA est déterminée par la capacité du rein à faire face à une diminution des ressources énergétiques, impliquant la protéine de stress NUPR1, et à la préservation d'une fonction mitochondriale, représentée par le rapport quinolinate (QA)/ tryptophane (Trp) urinaire (uQA/Trp). En effet, une augmentation du QA urinaire (~50 et ~20 μM pour les patients IRA et les personnes en bonne santé rénale, respectivement), génère une augmentation de l'uQA/Trp (~2,5/~1 : IRA/sain), aboutissant à un risque accru de développer l’IRA. NUPR1 est un facteur d'économie d'énergie qui protège les cellules épithéliales rénales de la mort cellulaire. Sa présence confère une résistance accrue à l'agression rénale lors de la phase aigüe de la maladie et présente donc une opportunité thérapeutique. Cependant, il n’existe actuellement aucune méthode standardisée pour détecter la protéine NUPR1 dans les tissus, en raison du manque d’anticorps disponibles et fiables. L'objectif de cette thèse est d'appliquer des polymères à empreinte moléculaire (MIP), également appelés anticorps biomimétiques, pour (i) monitorer l'état métabolique rénal en mesurant QA et Trp, afin de pouvoir prédire quand traiter le patient et (ii) développer de nouvelles approches thérapeutiques pour localiser NUPR1 dans les cellules par bioimagerie, et éventuellement pour stabiliser NUPR1 et contrôler son administration, lors de l'IRA. Pour le premier objectif, des MIP dotés de sondes fluorescentes ont été développés pour détecter et quantifier QA et Trp dans l'urine. Les MIP ont été synthétisés in situ sur des fibres optiques à ondes évanescentes permettant la détection de QA et Trp par spectroscopie de fluorescence d’une façon rapide et sensible. Dans la deuxième partie de la thèse, des nanogels de MIP (MIP-NG) monodispersés ayant une affinité (Kd: 18 nM) et une sélectivité élevées pour NUPR1, ont été synthétisés. Des applications préliminaires de bioimagerie sur des cellules rénales humaines exprimant NUPR1, ont montré que les MIP-NG fluorescents ciblaient NUPR1, présent dans et autour des noyaux cellulaires. En regardant à plus long terme, ces résultats ouvrent la voie au développement d’un système de bioanalyse médicale fonctionnelle destiné à être utilisé à la fois dans les laboratoires de biologie et au chevet du patient, pour le diagnostic et la surveillance dynamiques de l'IRA
Hybrid stress and heat‐flux formulation of thermodynamics for long‐term simulations in thermo‐viscoplasticity
No full textInternational audienceIn this article, we present a variational formulation for coupled problems in thermodynamics the most suitable for long‐term simulations of plastic behavior. We start with three‐field Hu–Washize variational formulation and perform regularization to include non‐symmetric stress, we thus recover the formulation that can accommodate any choice of discrete approximation. Such a regularized variational formulation allows us to eliminate the rotation field (as typically less important) and recover the corresponding hybrid stress format for equations of motion and transient heat conduction. The regularized variational formulation is further combined with discrete approximation based upon the Raviart–Thomas vector space for both mechanical and thermal fields, which enforces continuity across element boundaries for stress vector and normal component of heat‐flux. The conservation properties are validated with energy‐conserving scheme for thermoelastic behavior. The time integration of thermo‐viscoplastic behavior is carried out by energy‐decaying scheme to provide superior accuracy for computed stress in a long‐term simulation. The proposed approach offers higher computational robustness and results accuracy than the classical finite elements and time‐integration schemes. Such a performance is illustrated on several numerical simulations in non‐stationary problems for thermo‐viscoplastic behavior
A fully incremental simple triangular multilayer Kirchhoff-Love shell element
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Low-Cost Optical Filters Based on SiOxCy:H and Ag Thin Films Fabricated by Plasma Enhanced Chemical Vapor Deposition and Sputtering
No full textInternational audienceHexamethyldisiloxane (HMDSO) is an organosilicon compound with a modifiable bandgap, depending on the deposition conditions. This material has many unique properties due to its stability, low toxicity, and strong adhesion, making it useful as a protective barrier against corrosion, moisture, and oxidation. In this work, HMDSO films were deposited on glass substrates by the Plasma Enhanced Chemical Vapor Deposition (PECVD) technique at different deposition times. The optical properties of HMDSO films, such as dielectric permittivity, refractive index, extinction and absorption coefficients, and band gap energy, are inferred from transmission and reflection spectra. As the deposition time increased, the real part of the dielectric constant, the refractive index, and the bandgap energy showed a decrease, dropping from 4.24 to 3.40, from 2.06 to 1.84, and from 2.85 eV to 2.03 eV, respectively. The latter result is determined using classical models such as the O’Leary-Johnson-Lim (‘OJL’) interband transition and the harmonic oscillator model. HMDSO and Silver are used in this study for the fabrication of optical filters using two types of structures, a multiple cavity metal–dielectric (MCMD) and the Fabry–Perot structure. The silver layers are deposited by a sputtering process. The MCMD optical filter shows a higher transmittance of about 30%, but a wide range of wavelengths is transmitted. In contrast, the Fabry–Perot filter showed high contrast but a lower transmittance of about 20%
État de conservation d’un bien culturel. Précision sémantique et conceptuelle
No full textInternational audienceToday, the widespread adoption of Management Information Systems (MIS) continually challenges the standards of our documents, production processes, and the structuring of the information produced. Clarifying the semantics and conceptual underpinnings of the condition report is now imperative to ensure system interoperability and facilitate their migration. This article will clarify the meaning of the concept of state within the context of diagnostic evaluation and will integrate the scope of conservation-restoration, museum documentation, and linguistics through discursive textual analysis (DTA). After reviewing the current literature, which highlights the usage and meanings of the term state in specialised contemporary conservation-restoration literature, we will supplement our study using textometric tools with the analysis of foundational texts from the modern conservation-restoration discipline -texts which stem from different discursive formations, as defined by Foucault, but are yet intended for a same expert audience. We will show that the concept of state shifts from one discursive formation to another, moving from a physicalist register to a phenomenological perception. In this perspective, the state becomes the outcome of a holistic representation of the materiality, identity, and functionality of the object, based on an underlying shared memory and common referenceAujourd'hui, la généralisation des systèmes d'information de gestion (SIG) ne cesse de réinterroger les standards de nos documents, les processus de production et la structuration de l'information produite. La clarification sémantique et conceptuelle du constat d'état s'avère aujourd'hui impérieuse afin de garantir une interopérabilité des systèmes d'information et de leur migration. Cet article précisera le sens du concept état dans le cadre de l'examen diagnostique et s'inscrira dans les champs disciplinaires de la conservation-restauration, de la documentation muséale et de la linguistique par l'analyse discursive textuelle (ADT). Après un état de l'art, relevant les usages et sens du terme état dans la littérature contemporaine spécialisée en conservation-restauration, nous compléterons cette étude, à l'aide d'outils textométriques, par l'analyse de textes fondateurs de la discipline moderne de la conservation-restauration, relevant de formations discursives (FD) différentes, au sens foucaldien du terme, mais adressées à un même public expert. Nous démontrerons que le concept d'état passe d'une formation discursive à l'autre sortant d'un registre physicaliste pour s'inscrire dans une perception phénoménologique. L'état est alors la résultante d'une représentation holistique de la matérialité, de l'identité et de la fonctionnalité du bien, basé sur une mémoire et des références sous-jacentes communes