Magneto-Elastic Resonance: Principles, Modeling and Applications

The magnetostriction effects are first discussed in the frame of the magneto-elastic resonance to define important values mainly the magneto-elastic coupling factor, k33. We review the different magnetostrictive materials according to their developments, with a special attention to amorphous ribbons to design magnetostrictive resonators. Furthermore, we focus on the current instrumental setups including their limitations, and then on the usual measurement procedures of the resonators, particularly the frequency domain measurement. In addition, an innovative approach based on the magneto-elastic impedance is reported, together with an analytical model which establishes the complete transfer function between the input and output voltages. This model is applied to ribbon-shaped materials, particularly to determine the magneto-elastic coupling factor. These resonators are suitable to sensing applications, i.e., to estimate the influential quantities such as the temperature, magnetic fields and mass stuck on the resonating surface

Qualitative physics in virtual environments

In this paper, we describe a new approach to the creation of virtual environments, which uses qualitative physics to implement object behaviour. We adopted Qualitative Process Theory as a qualitative reasoning formalism, due to its representational properties (e.g., its orientation towards process ontologies and its explicit formulation of process’ pre-conditions). The system we describe is developed using a game engine and takes advantage of its event-based system to integrate qualitative process simulation in an interactive fashion. We use a virtual kitchen as a test environment. In this virtual world, we have implemented various behavioural aspects: physical object behaviour, complex device behaviour (appliances) and “alternative” (i.e. non-realistic) behaviours, which can all be simulated in user real-time. After a presentation of the system architecture and its implementation, we discuss example results from the prototype. This approach has potential applications in simulation and training, as well as in entertainment and digital arts. This work also constitutes a test case for the integration of an Artificial Intelligence technique into 3D user interfaces

New behavioural approaches for virtual environments

We describe a new approach to the behaviour of 3D environments that supports the definition of physical processes and interactive phenomena. The work takes as a starting point the traditional event-based architecture that underlies most game engines. These systems discretise the environments' Physics by separating the objects' kinematics from the physical processes corresponding to objects interactions. This property has been used to insert a new behavioural layer, which implements AI-based simulation techniques. We introduce the rationale behind AI-based simulation and the techniques we use for qualitative Physics, as well as a new approach to world behaviour based on the induction of causal impressions. This is illustrated through several examples on a test environment. This approach has implications for the definition of complex world behaviour or non-standard physics, as required in creative applications

La question de la modélisation en sciences humaines : mathématiques et informatique

Jean Petitot, Marc Barbut, Georges Guilbaud, Hervé Le Braset Pierre Rosenstiehl, directeurs d’étudesavec Jean-Pierre Desclés, professeur à l’Université de Paris-IV Enseignement suspendu durant l’année universitaire 2000-2001

A Standardized Workflow Based on the STAVIRO Unbaited Underwater Video System for Monitoring Fish and Habitat Essential Biodiversity Variables in Coastal Areas

Essential Biodiversity Variables (EBV) related to benthic habitats and high trophic levels such as fish communities must be measured at fine scale but monitored and assessed at spatial scales that are relevant for policy and management actions. Local scales are important for assessing anthropogenic impacts, and conservation-related and fisheries management actions, while reporting on the conservation status of biodiversity to formulate national and international policies requires much broader scales. Measurements must account for the fact that coastal habitats and fish communities are heterogeneously distributed locally and at larger scales. Assessments based on in situ monitoring generally suffer from poor spatial replication and limited geographical coverage, which is challenging for area-wide assessments. Requirements for appropriate monitoring comprise cost-efficient and standardized observation protocols and data formats, spatially scalable and versatile data workflows, data that comply with the FAIR (Findable, Accessible, Interoperable, and Reusable) principles, while minimizing the environmental impact of measurements. This paper describes a standardized workflow based on remote underwater video that aims to assess fishes (at species and community levels) and habitat-related EBVs in coastal areas. This panoramic unbaited video technique was developed in 2007 to survey both fishes and benthic habitats in a cost-efficient manner, and with minimal effect on biodiversity. It can be deployed in areas where low underwater visibility is not a permanent or major limitation. The technique was consolidated and standardized and has been successfully used in varied settings over the last 12 years. We operationalized the EBV workflow by documenting the field protocol, survey design, image post-processing, EBV production and data curation. Applications of the workflow are illustrated here based on some 4,500 observations (fishes and benthic habitats) in the Pacific, Indian and Atlantic Oceans, and Mediterranean Sea. The STAVIRO’s proven track-record of utility and cost-effectiveness indicates that it should be considered by other researchers for future applications.publishedVersio