This paper proposes an anonymity based mechanism for providing privacy in IoT environment. Proposed scheme allows IoT entities to anonymously interacting and authenticating with each other, or even proving that they have trustworthy relationship without disclosing their identities. Authentication is based on an anonymous certificates mechanism where interacting IoT entities could unlinkably prove possession of a valid certificate without revealing any incorporated identity-related information, thereby preserving their privacy and thwarting tracking and profiling attacks. Through a security analysis, we demonstrate the reliability of our solution.
Les systèmes industriels deviennent plus complexes en raison, notamment, de leur taille croissante et de l’intégration des nouvelles technologies. En vieillissant, ces systèmes deviennent plus vulnérables aux défaillances et leurs activités de maintenance sont difficiles et coûteuses. Cette situation, combinée aux exigences de productivité, de croissance des bénéfices, de disponibilité opérationnelle et de sécurité, pousse les praticiens et les chercheurs à développer des outils et des méthodes innovants. Les activités de maintenance constituent l’un des leviers possibles. En entretenant le système, nous pouvons réduire les coûts globaux de son cycle de vie, augmenter sa disponibilité, améliorer la sécurité des opérateurs et réduire les incidents environnementaux. Les tâches de maintenance peuvent être soit curatives, soit préventives. Cependant, cela n’est pas encore suffisant parce que les pièces de rechange ne sont pas disponibles ou pas suffisantes au moment de la panne ou simplement parce que les ressources nécessaires (les responsables de la maintenance) sont occupées. Une "meilleure" solution pourrait alors être une maintenance prédictive, qui peut être effectuée dans le framework du pronostic. Dans ce cadre nous essayons de prévoir l’état de santé du système, puis on planifie les actions appropriées en fonction des résultats des prévisions. Ce travail s’inscrit dans au domaine du pronostic de la PHM et de la gestion de la santé. Les techniques de PHM visent à prédire la durée de vie restante de l’équipement. Cependant, elles ont eu tendance à être utilisées dans un contexte local avec une intégration limitée des solutions distribuées. Dans les systèmes complexes, le comportement émergent est plus compliqué que la somme des comportements de leurs parties constitutives. Ce comportement implique la propagation de défauts entre les parties et nécessite des informations sur la fa\c con dont les parties sont liées. Dans cette thèse, nous proposons une approche multi-agent pour la prédiction de la RUL au niveau du système. Ensuite, l’approche proposée est étendue à la PHM médicale avec une étude de cas
The assessment of Patient Safety Culture (PSC) is often conducted using a quantitative approach based on questionnaires or a qualitative one focused on the deployment of Patient Safety Culture Maturity Models (PSCMM). These two approaches suffer from a number of limitations and their resolution is only possible by exploiting the possible complementarity that exists between them. Indeed, to overcome their inherent limits, it is imperative to merge the two PSC approaches in a single approach called quali-quantitative evaluation of PSC. This article fits into this context and aims to materialise the merger of PSC approaches through their co-deployment. This will make it possible to capitalise the scores of the HSOPSC dimensions in terms of PSC maturity levels.
Improvements to health and safety at work constantly involve organizational changes (OCs). However, the OC initiatives often fail at achieving their intended goals despite efforts to draw knowledge from various disciplines, such as sociology, psychology and information sciences, to guide the change implementation. This paper proposes a temporality approach to manage the resistance during an OC project based on the capitalization of the actors’ behaviors (i.e. alignment/resistance) for successful OC implementation.Employees in an industrial company (N = 186) undergoing an OC answered a questionnaire survey. The statistical analysis approach was used to measure the influence of the constructs of the proposed temporality capitalization approach on the OC conduct.Results indicate that the considered constructs have positive and significant correlations with OC development. It has also been found that the employees’ alignment is highly correlated with the opportunities they might gain from the OC.The proposed temporality capitalization approach shows that providing the employees with clear objectives is not sufficient to support the change, and it is suggested that the change management has to move a step further and seek to target the perspectives of the employees to energize them around the OC and maximize their alignment.In this paper, change management is approached through the temporality capitalization that confirms the importance of monitoring the change development through the alignment. In other terms, the curve of the adaptation of the change receivers matters and should attract more attention rather than the change implementation speed.
Cette thèse traite de l’utilisation d’un outil de Machine Learning appelé "Extreme Learning Machine" dans le domaine du pronostic et de l’évaluation de la santé (e.g. estimation de la durée de vie utile restante (RUL)). Cet algorithme implique des méthodes de programmation linéaires qui reposent principalement sur les moindres carrés dans les paradigmes non linéaires des réseaux de neurones artificiels pour produire des estimateurs de santé très rapides et précis. D’autres parts, cette étude vise à distribuer le système de prédiction sur le web à l’aide de services Web pour résoudre les problèmes de répartition géographique de surveillance décentralisée. Sur la base de ce nouvel outil, de nombreux algorithmes d’apprentissage ont été développés dans le cadre de ce travail et comparés à d’autres algorithmes présents dans la littérature en termes de temps et de précision. La plupart des algorithmes développés sont inspirés des théories récentes de Deep Learning et ce en raison de leur bonne réputation. Les données étudiées dans ce travail de recherche sont tirées du logiciel C-MAPSS simulateur de système de propulsion aérodynamique développé par la NASA. Les résultats obtenus ont prouvé l’efficacité des nouveaux algorithmes et les recommandent pour une utilisation future dans le domaine de l’évaluation de la santé.
Le contexte actuel de globalisation et de concurrence accrue a entrainé les firmes à reconsidérer leurs stratégies d’internationalisation et à réexaminer les opportunités offertes et les risques associés. Les alliances stratégiques apparaissent ainsi comme des vecteurs privilégiés notamment par les firmes multinationales pour leurs nouvelles implantations.La communication et le travail d’équipe sont parmi les compétences les plus récurrents associés à une connaissance des sciences de l’ingénieur. Cependant, leur application n’est pas simple, en raison de l’absence d’approche pédagogique contribuant à développer des connaissances fondées sur l’expérience.Dans ce travail nous avons défini qu’est-ce qu’une organisation apprenante, qu’est-ce qu’un tutoriel et pourquoi un tutoriel personnalisé dans un métier, ses différentes formes et les démarches pour l’élaboration d’un tutoriel.Après nous avons donné une présentation de l’entreprise qu’est Textile Batna. Nous avons con\c cu un tutoriel pour l’entreprise sous forme d’un site Web. Pour cela, le langage UML a été utilisé. Les fonctionnalités du tutoriel ont été présentées.
The stability and strength of slender Reinforced Concrete (RC) columns depend directly on the flexural stiffness EI, which is a major parameter in strain calculations including those with bending and axial load. Due to the non-linearity of the stress-strain curve of concrete, the effective bending stiffness EI always remains variable. Numerical simulations were performed for square and L-shaped reinforced concrete sections of slender columns subjected to an eccentric axial force to estimate the variation of El resulting from the actual behavior of the column, based on the moment-curvature relationship. Seventy thousand (70000) hypothetical slender columns, each with a different combination of variables, were used to investigate the main variables that affect the EI of RC slender columns. Using linear regression analysis, a new simple and linear expression of EI was developed. Slenderness, axial load level, and concrete strength have been identified as the most important factors affecting effective stiffness. Finally, the comparison between the results of the new equation and the methods proposed by ACI-318 and Euro Code-2 was carried out in connection with the experimental results of the literature. A good agreement of the results was found.
Two dihydropyrimidinone derivatives (DHPM) were synthesized via the multi-component reaction, the yield of the synthesis reached 90%, and their structures were proved by IR, 1H and 13C NMR spectroscopy. The identified molecules were used for studying the corrosion inhibition of XC48 carbon steel in 0.5 mol L-1 H2SO4 solution. The inhibitory potentials of these compounds were determined by electrochemical methods exploiting the potentiodynamic polarization curves (Tafel method) and electrochemical impedance spectroscopy. Surface phenomena have been illustrated by atomic force microscopy. The results obtained show that the synthesized molecules are effective inhibitors, whose efficiency corrosion inhibition depends on the architecture of their structure, and it is proportional to the concentrations; it exceeds 94% for one of these inhibitors. The adsorption of these compounds on the metal surface approached the Langmuir’s adsorption isotherm. Furthermore, the electronic properties obtained using density function theory are in a good consensus with the experimental efficiencies of inhibition. The molecular dynamics simulations have allowed also simulating the interactions between the inhibitors and the metallic surface.
Nickel chloride (NiCl2) is a heavy metal that may affect the function of the thyroid. Selenium (Se) and zinc (Zn) are essential trace elements involved in thyroid hormone metabolism. However, little is reported about thyrotoxicity during gestation. The current study aimed to investigate the protective effects of selenium and zinc against NiCl2-induced thyrotoxicity in pregnant Wistar rats. Female rats were treated subcutaneously (s.c.) on the 3rd day of pregnancy, with NaCl 0.9% and served as control, NiCl2 (100 mg/kg body weight (BW)) alone, or in association with Se (0.3 mg/kg, s.c.), ZnCl2 (20 mg/kg, s.c.), or both of them simultaneously. Oxidative stress parameters, thyroid biomarkers, and histopathological examination were evaluated. Results showed that NiCl2 exposure caused a significant decrease in maternal body weight and an increase in absolute and relative thyroid weight compared to the controls. NiCl2 administration also led to decreased plasma triiodothyronine (T3) and thyroxine (T4) with a concomitant significant increase in thyroid-stimulating hormone (TSH) levels when compared to that of control. In addition, an overall pro-oxidant effect was associated with a decrease in the reduced glutathione (GSH) and nonprotein thiol (NPSH) contents and the enzymatic activity of glutathione peroxidase (GPx) and superoxide dismutase (SOD), and an increase in malondialdehyde (MDA). These biochemical disturbances were confirmed by histological changes. However, the co-treatment of Se and/or ZnCl2 attenuates NiCl2-induced changes. Our findings suggested that Se and ZnCl2 ameliorated NiCl2-induced thyrotoxicity in pregnant Wistar rats by exhibiting antioxidant effects.
Hexavalent chromium (CrVI) is an environmental pollutant and an endocrine-disrupting metal. Se and Zn are essential trace elements, known to play a crucial role in thyroid homeostasis. However, there is a lack of data reporting thyrotoxicity during gestation. In this study, we investigated the protective effects of selenium and zinc against potassium dichromate–induced thyrotoxicity in pregnant Wistar rats. Thirty pregnant Wistar rats were divided into control and four treated groups receiving subcutaneously (s.c) on the 3rd day of pregnancy, K2Cr2O7 (10 mg/kg, s.c) alone, or in association with Se (0.3 mg/kg, s.c), ZnCl2 (20 mg/kg, s.c), or both of them simultaneously. The hormonal profile, oxidative stress biomarkers, DNA damage, and histological modifications were evaluated. Our main findings showed that K2Cr2O7 promoted hypothyroidism, oxidative stress, genotoxicity, and histological alterations in the thyroid gland. The co-treatment with Se or ZnCl2 has mitigated K2Cr2O7-induced thyrotoxicity in pregnant Wistar rats by exhibiting antioxidant and genoprotective effects. However, the combined co-treatment of both of them was less thyroprotective, and therefore, further investigations on the synergetic interaction of Se and Zn against CrVI toxicity using different doses and exposure routes are required.