Strain Patterns With Ultrasound for Assessment of Abdominal Aortic Aneurysm Vessel Wall Biomechanics

International audienc

Coupling Variable Selection and Anomaly Detection: Record-Based Approach

International audienceThe proliferation of interconnected devices is rapidly expanding globally, and, as a result, telecommunication operators are responsible for managing intricate and expansive networks. Consequently, there is a need for advanced and efficient systems to aid network engineers in maintaining these networks. Devices, which can also be referred to as network elements, continuously transmit essential performance data known as key performance indicators. By utilizing data derived from these metrics and implementing intelligent anomaly detection models, the devices can assist in determining the optimal production maintenance schedule for the network. As anomaly detection models deal with extreme events, this study proposes a method of reducing dimensions by focusing on the behavior of the tails of underlying variables, rather than the entire distribution. In addition to that, an anomaly scoring system, also based on records theory, is proposed, which has several advantages over current state-of-the-art models. The effectiveness of this approach is demonstrated by implementing it on a real-world dataset

Life Cycle Assessment of Concrete Recycling Solutions in Light of Their Technical Complexity

International audienceWaste management is a key step for addressing both the environmental impact and the growing demand for resources in the construction industry. To answer these challenges, various technologies are available, carrying different environmental impacts and sociotechnical implications. For concrete waste, recycling is the most common solution. Two main recycling roads were identified, leading to products that have low or high value and implying different technical developments and environmental impacts. This study first proposed to characterize recycling technologies by their technical degree, reflecting the complexity needed to process waste. It secondly compared their environmental impacts using LCA methodology to assess which technical complexity led to minor environmental consequences and under what conditions. The results revealed that the technologies with a low technical degree tended to have a lower environmental impact than the ones with a higher technical degree when only the generated impacts were considered. The reverse was observed when considering the aggregated impacts due to the environmental benefits provided by the potentially avoided products

Gestion de la montée en puissance des services en tenant compte de la durabilité et des risques

This PhD research explores the development of service ramp-up management, a multidisciplinary concept that encompasses the processes and strategies employed to effectively introduce and rapidly scale services in today’s dynamic business environment. This research addresses the complexities associated with service ramp-up and aims to answer two simple but fundamental research questions (RQs) in this context; When and How to ramp-up a service. To achieve these objectives, the research employed a Design Science Research (DSR) methodology, beginning with a systematic literature review (SLR) on decision-making in ramp-up management (DMiRM). A conceptual framework, obtained from the SLR funding, is proposed to provide a structured approach for DMiRM and guide decision-makers in ramp-up strategies. The research then focuses on agile ramp-up concept as an emerging paradigm crucial for the successful execution of service ramp-up projects. A conceptual Framework has been proposed for agile ramp-up phase to answer the first RQ: When to ramp-up. This framework, structured around five key stages and agile stage-gate model, underscores the importance of iterative development and continuous improvement in the context of service ramp-up. As the primary contribution of this research, this PhD research proposes a comprehensive framework namely “Agile Ramp-up Framework for Escalation Stage (ARFES)” to address the second RQ: How to ramp-up. ARFES integrates structured yet flexible approaches, enabling organizations to rapidly and swiftly adapt to evolving market conditions and customer demands. Moreover, ARFES incorporates a range of concepts, techniques, and methodologies including agility and agile principles, simulation , sustainability and performance indicators, risk management, and Business Process Standardization (BPS), to facilitate systematic and iterative process performance improvements. Following the designated DSR methodology, the framework was evaluated and refined through two iterations: a content validity assessment and a detailed practical use case in a Additive Manufacturing Service.Cette thèse explore la gestion de la montée en puissance des services, un concept multidisciplinaire visant à introduire et développer rapidement des services dans un environnement dynamique. Elle répond à deux questions fondamentales : Quand et comment intensifier un service. Une méthodologie de recherche en sciences de la conception (DSR) a été employée, incluant une revue systématique de la littérature (SLR) sur la prise de décision dans ce domaine. Un cadre conceptuel structuré, basé sur le modèle agile principales et le stage-gate, a été développé pour répondre à la question quand intensifier, en mettant en avant l'importance du développement itératif et de l'amélioration continue. La contribution principale est le cadre « Agile Ramp-up Framework for Escalation Stage » (ARFES), qui répond à la question comment intensifier. ARFES intègre principes agiles, simulation, durabilité, gestion des risques et standardisation des processus pour améliorer les performances de manière systématique et itérative.Validé par une évaluation de contenu et une étude de cas pratique dans la fabrication additive, ce cadre offre aux organisations une approche flexible pour s'adapter aux marchés en constante évolution

Electric charges as an apparent governing parameter for electron induced stress relaxation in amorphous silica micropillars

International audienceWe report a new approach on the phenomenon of plastic flow induced by electron irradiation in amorphous silica, revealing that the total injected electric charge is the governing parameter of the mechanical response: micropillar relaxation tests conducted under electron irradiation showed a one-to-one relationship between the injected electric charge and the measured mechanical stress level, regardless of the applied current. Moreover, by performing these tests at high temperature, we have found that the effects of electronic processes and temperature are decoupled. This result suggests that under the present irradiation/temperature conditions, the density of flow defects is controlled only by irradiation, while the plastic rearrangement of the defects depends only on temperature

New deep learning-based algorithm to assess quality of primary corneal endothelial cell cultures

International audienceThe development of cell therapies to treat corneal endothelial pathologies requires characterizing the cells during the cell culture process. The endothelial cell density (ECD) and morphometry are essential parameters for identifying cultures with sufficient phenotype and yield. However, they are difficult to measure on cells in culture using conventional image analysis tools. Aims: (1) To develop an AI-based automatic cell segmentation method for reliable ECD and morphology measurement. (2) To select new morphometry parameters. (3) To classify endothelial cell cultures by quality

A laser-based annealing methodology to speed-up the study of thermo-activated restoration mechanisms in metals

International audienceThe properties of polycrystalline materials are significantly influenced by annealing treatments. This article introduces a laser-annealing method that facilitates the investigation of high-temperature transformations, with a specific focus on tungsten restoration. The aim of this research is to establish a controlled temperature gradient in the examined sample to expedite the study of restoration at high temperatures by reducing the number of samples. To achieve this, simulations are employed to design the desired temperature profile, and a laser-based setup is adapted to generate and regulate this profile. Furthermore, uncertainties and errors associated with temperature measurements in the experimental setup are quantified. The proposed laser-annealing method enables precise temperature control during the annealing process. By heating one side of a tungsten rod using the laser system, a steady-state temperature gradient is induced. The annealing process consists of two steps: the initial heating phase to reach the desired temperature profile, followed by the maintenance of constant Temperatures at specific positions along the rod for a defined duration. The study investigates the impact of absorbed power by the sample on the temperature profile and assesses the softening of tungsten after annealing using hardness measurements. Overall, the proposed laser-annealing method offers a promising avenue for advancing material science research. Its ability to precisely control temperature gradients and observe material behaviors at high temperatures opens up new opportunities to optimize the properties of polycrystalline materials beyond tungsten, thus providing broader applications in material engineering and manufacturing

L’aide à la décision pour les transitions énergétiques et environnementales des territoires et organisations

En effet, face aux enjeux environnementaux majeurs — crise climatique, raréfaction des ressources, érosion de la biodiversité — les transitions énergétiques et environnementales imposent une transformation des pratiques et appellent à repenser les processus de décision.Deux axes de recherche principaux structurent ces travaux de recherche :Les Meilleures Techniques Disponibles (MTD) : évaluation et amélioration des méthodes d’analyse des performances environnementales des sites industriels, avec une portée locale et internationale.La rénovation énergétique des bâtiments : développement d’outils, notamment l’Observatoire National des Bâtiments, pour mieux connaître le parc immobilier et identifier les gisements d’économie d’énergie à l’échelle territoriale.L’ensemble de ces recherches vise à outiller la décision pour accompagner les transitions, en tenant compte de la complexité des enjeux et de la diversité des acteurs impliqués

Omega-X Common Semantic Data Model

International audienc

Les niveaux de la participation citoyenne

National audienc