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Invited presentation - Visiting University of Reno, USA

A numerical approach is proposed to model the reverberated sound field in rooms. The model is based on the numerical implementation of a diffusion model enabling spatial variations of the sound energy within a room, unlike the statistical theory. The proposed method allows to take into account most of complex phenomena encountered in room acoustics, like mixed reflections on walls (diffuse and specular), low and high absorption on walls, atmospheric attenuation, fitted zones. Moreover, the model can be applied to complex geometries, like multiple coupled rooms of different sizes. In this paper, the model and its numerical implementation are first detailed. Then, an application is proposed for a complex geometry defined by multiple coupled rooms with fitting objects, including low and high absorption on walls, in terms of sound level and reverberation times. The main interest of the model is that such approach requires less computational time in comparison with common approaches like ray-tracing simulations.

International audience

GPS positioning and map-matching are key technologies used in Car Navigation Systems. Next generation of Cooperative Vehicle Infrastructure Systems (CVIS) will surely require positioning component with higher accuracy, integrity and availability, for instance for the needs of lanelevel applications. The concept of Map Aided Location (MAL) was introduced recently: it consists in considering the map contents (geometry and topology) as constraints in the positioning problem. The main contribution of the work reported in this article concerns the evolution model of the vehicle : whereas previous research investigations were based on usual models in plane coordinates, we propose here an evolution model adapted to the local curvature of the road. Therefore, road constraints are emphasized, particularly when GPS outages occur. An enhanced map (Emap) - where all lanes are represented with decimeter accuracy - is used in this Map Aided Location process.

Mémoire de stage; The use of adhesively bonded composite reinforcement for steel structures induce a closer study of the adhesive as it is considered the weakest point in the assembly. A reliable numerical damage model has been developed for the adhesively bonded joints and then verified for different types of configurations. A bi- linear traction separation description of a cohesive zone model was used in ABAQUS to simulate the damage evaluation in the adhesive. It was then compared to experimental results for the global structure behavior (local strains, applied load, applied displacement).; L'utilisation des renforcements par composites collés pour des structures métalliques implique une étude plus approfondie des adhésifs puisqu'il s'agit dans ce cas de l'élément le plus faible dans l'assemblage. Un modèle d'endommagement numérique a été développé pour le joint collé étudié et appliqué pour diffèrent type de configurations. Le modèle bi linéaire de traction- séparation (modèle de zone cohésives) est réalisé sur ABAQUS pour visualiser l'évaluation de l'endommagement de l'adhésive et pouvoir réaliser une comparaison avec les investigations expérimentales (déformation locale, effort appliqué, déplacement appliqué).

Aim: This paper explores the real practices of users of a smart carpooling application that learns their mobility habits and predicts their future trips to propose relevant matches. Method: A combination of usage data and interviews analysis allows us to explore the commuter experience from registration to the first and the next shared rides. Findings: The results highlight the shortcomings associated with human factors in carpooling and with human-smart system interactions. They show that perceptions of practical constraints and poor counterparts are the major reasons for difficulty in incorporating carpooling into daily mobility. Psychosocial barriers take different forms at different steps of the carpooling experience (search for information or guarantees about other users, the necessity of conversing with others, much uncertainty about how to behave). The fact that the service is smart amplifies these problems and reduces the desire to carpool again because it creates new misunderstandings (i.e., the user does not understand what the system vs. the other users do) and discomfort in relation to other riders (no answer, too many refusals, necessity of refusing, negative carpool experience, or concern over proposing a bad carpool). Despite these difficulties, the users perceive carpooling as a good solution and a positive human experience when the matching is accurate. We propose some recommendations to overcome the identified difficulties.

A numerical model is proposed to predict the reverberant sound field in a system of two coupled volumes that are connected through an open aperture. The model is based on the numerical implementation of a diffusion model that has already been applied to predict the sound-energy distribution and the sound decay in single rooms. In comparison with the statistical theory, the proposed approach permits the prediction of the sound field by taking into account the sound source location and the receiver locations as well as the transition from one room to the other at the coupling aperture. Moreover, the diffusion model results match satisfactorily the experimental data in terms of sound-pressure level and reverberation times, both in the room containing the source and in the receiving room. Simulations with a ray-based model are also carried out, leading to results similar to those of the diffusion model, but at a cost of larger computation times.

Présentation du projet NoiseCapture dans le cadre du séminaire Immersion Sciences 2018, organisé conjointement par l’Académiede Rennes, la région Bretagne et le CNRS.

BACKGROUND: The exposome is defined as the totality of environmental exposures from conception onwards. It calls for providing a holistic view of environmental exposures and their effects on human health by evaluating multiple environmental exposures simultaneously during critical periods of life. OBJECTIVE: We evaluated the association of the urban exposome with birth weight. METHODS: We estimated exposure to the urban exposome, including the built environment, air pollution, road traffic noise, meteorology, natural space, and road traffic (corresponding to 24 environmental indicators and 60 exposures) for nearly 32,000 pregnant women from six European birth cohorts. To evaluate associations with either continuous birth weight or term low birth weight (TLBW) risk, we primarily relied on the DeletionSubstitution-Addition (DSA) algorithm, which is an extension of the stepwise variable selection method. Second, we used an exposure-byexposure exposome-wide association studies (ExWAS) method accounting for multiple hypotheses testing to report associations not adjusted for coexposures. RESULTS: The most consistent statistically significant associations were observed between increasing green space exposure estimated as Normalized Difference Vegetation Index (NDVI) and increased birth weight and decreased TLBW risk. Furthermore, we observed statistically significant associations among presence of public bus line, land use Shannon's Evenness Index, and traffic density and birth weight in our DSA analysis. CONCLUSION: This investigation is the first large urban exposome study of birth weight that tests many environmental urban exposures. It confirmed previously reported associations for NDVI and generated new hypotheses for a number of built-environment exposures.

European Research Area - Network on the Industrial Handling of Raw Materials for European Industries; roadmap of the "ERA-MIN" eranet; Non-energy and non-agricultural raw materials underpin the global economy and our quality of life. They are vital for the EU's economy and for the development of environmentally friendly technologies essential to European industries. However, the EU is highly dependent on imports, and securing supplies has therefore become crucial. A sustainable supply of mineral products and metals for European industry requires a more efficient and rational consumption, enhanced substitution and improved recycling. Recycling from scrap to raw materials has been rapidly gaining in quantity and efficiency over the last years. However, continuous re-use cannot provide alone the necessary quantities of mineral raw materials, due to i) recycling losses, ii) the worldwide growing demand in raw materials, and iii) the need of "new" elements for the industry. To fully meet future needs, metals and mineral products from primary sources will still be needed in the future. Most of them will continue to be imported from sources outside Europe; but others can, and should, be produced domestically. Advanced research and innovation are required to improve the capacity of existing technologies to discover new deposits, to improve the efficiency of the entire geomaterials life cycle from mineral extraction to the use as secondary resource of products at the end of their industrial life, and to reduce the environmental footprint of raw materials extraction and use. Research and innovation must be made to acquire knowledge as well, and to improve our basic understanding of all engineering and natural processes involved in the raw materials life cycle, as well as the coupling of these processes. Finally, research has to go beyond the present-day economic and technological constraints, and it should be closely associated with training and education in order to maintain existing skills and to share the most recent developments with the industrial sector. A long-term vision of research is necessary in order to have the capacity of evaluating the environmental and societal impacts of present and developing industrial activities and to imagine tomorrow's breakthrough concepts and technologies that will create new industrial opportunities. These objectives require the input of contrasted scientific and technical skills and competences (earth science, material science and technology, chemistry, physics, engineer, biology, engineering, environmental science, economy, social and human sciences, etc). An important challenge is to gather all these domains of expertise towards the same objective. The ERA-MIN Research Agenda aims at listing the most important topics of research and innovation that will contribute to i) secure the sustainable supply and management of non-energy and non-agricultural raw materials, and ii) offer opportunities of investment and employment opportunities in the EU.