Portail HAL edf
Not a member yet
11029 research outputs found
Sort by
Signalling for electricity demand response: When is truth telling optimal?
No full textUtilities and transmission system operators (TSO) around the world implement demand response programs for reducing electricity consumption by sending information on the state of balance between supply demand to end-use consumers. We construct a Bayesian persuasion model to analyse such demand response programs. Using a simple model consisting of two time steps for contract signing and invoking, we analyse the relation between the pricing of electricity and the incentives of the TSO to garble information about the true state of the generation. We show that if the electricity is priced at its marginal cost of production, the TSO has no incentive to lie and always tells the truth. On the other hand, we provide conditions where overpricing of electricity leads the TSO to provide no information to the consumer
CONSEQUENCES AND ECONOMIC CONDITIONS OF TECHNICAL SIZING FOR LONG-TERM FLEXIBILITIES IN A FULLY RENEWABLE POWER SYSTEM
No full textInternational audienc
Why new metadata? Avenues for improvement in the describing and storing of restoration monitoring data
No full textInternational audienceAssessing the effectiveness of restoration requires monitoring data. However, the collection of such data is subject to bias, making it difficult to distinguish between actual changes in the environment and variability in the conditions under which the data were collected. Metadata, which provide contextual information about data collection and compilation, are essential for analyzing data and accounting for potential collection biases. Given the lack of specific standards for describing and storing ecological restoration monitoring data, we questioned whether current data standards are sufficient for this purpose. A literature review was conducted to 1/provide a non-exhaustive list of metadata required to describe the restoration monitoring data collection process, with a focus on species data collection and 2/identify the main standards currently used to store ecological data at international, European and national (France) levels. We found that the most commonly used standards are DarwinCore, the Ecological Metadata Standard (EML), the Humboldt extension, the FGDC Biological Data Profile worldwide, the European INSPIRE standard in Europe, and the Système d'Information du Patrimoine Naturel (SINP) in France. Finally, we compared our list of metadata from the literature review and the list of metadata from the main standards. Our results indicate that (i) these standards are applicable to a wide range of biological and ecological data, (ii) they are not specifically designed for monitoring data, and (iii) they do not include enough fields for a complete description of these data. Our list of metadata could therefore complement the main metadata standards for describing and storing restoration monitoring data
Une opinion publique numérique entre opinions privées et sentiment public
No full textInternational audienceCe texte passe en revue les dispositifs théoriques et empiriques d’analyse de l’opinion publique numérique expérimentés à EDF R&D. Il s'agit de rendre compte à la fois de la mobilisation des affects individuels et des dynamiques de publicisation des arguments. Ce sont plus particulièrement les disputes sur le sens des émotions collectives, les raisons qui les justifient ou les rendent illégitimes publiquement qui permettent de comprendre comment la diffusion d’une émotion collective peut donner naissance à un mouvement d’opinion publique
SynKGP: Knowledge Graph Population with Syntactic-LLM Hybridation for Question-Answering
No full textInternational audienceInformation Retrieval (IR) from structured data is facilitated by schemas such as ontologies, which enable efficient data access and organization. However, most knowledge is recorded in unstructured formats using natural language, which induces additional efforts to retrieve information. Retrieval Augmented Generation (RAG) has been developed to support general IR in unstructured text, yet it often produces inconsistencies due to model limitations. To address these inconsistencies, we propose transforming unstructured texts into structured information using text-to-Knowledge Graph (KG) translation. KGs support robust retrieval and reasoning tools, making them well-suited for complex knowledge representation. They are also understandable for humans. Our approach employs open-ended information extraction (for node extraction) and open-ended relation extraction (for relation extraction). To ensure the fidelity of the information present in the input text, we want to leverage a new combination of syntactic analysis for entity and relation extraction and Large Language Model (LLM) analysis to link the entities together. Initial implementations of this pipeline showed that our method effectively produces understandable and queryable KG
Orchestrating an interoperable sovereign federated Multi-vector Energy data space built on open standards and ready for GAia-XD4.4 Data ingestion, Common Information Model and semantic interoperability. Final version
No full text"D4.4 - Data ingestion, Common Information Model and semantic interoperability" is the second edition of OMEGA-X_D4.1 - Data ingestion, Common Information Model and semantic interoperability" [1]. Deliverable OMEGA-X_D4.4 documents the implementation for OMEGA-X federated infrastructure of the needed data adapters, tailored to the demo case requirements, and the agreement and implementation of a Common Information Model ruling the data exchange in the Data Space
Derivation of model-consistent universal functions for second-order turbulence models and their implications on Lagrangian stochastic methods for thermally stratified atmospheric surface boundary layer flows
No full textInternational audienceThe aim of this paper is to provide a description of high-Reynolds-number thermally stratified surface-boundary-layer flows consistent with given turbulence models and to study their implications on Lagrangian stochastic approaches. The emphasis is first put on the relations between the selected turbulence models and the resulting universal functions used to describe the first- and second-order moments for temperature and velocity. To this end, a methodology for deriving model-consistent mean profiles that agrees with the Monin–-Obukhov theory is presented. This methodology is based on the derivation of algebraic solutions for the thermal and dynamic second-order moments, and on an iterative resolution of the turbulent dissipation rate. With adequate models for the dissipation rate, it is shown that the derived universal functions for the first- and second-order moments retrieve the correct asymptotic behaviors for both the stable and unstable limits. Based on these formulations, the consequences on Lagrangian stochastic models are then investigated since the turbulent model corresponding to the Lagrangian description must be consistent with the one used in the moment approach. For example, when using wall-function formulations, we highlight the importance of applying an-elastic wall-boundary conditions for both velocity and thermal instantaneous properties. Finally, an application to the case of linear-source dispersion is analyzed in the frame of hybrid moment–probability density function methods. It is shown that these methods can adequately account for stability effects and that models of instantaneous thermal quantities have a great impact on both buoyant plume rise and dispersion
Power comparison of sequential testing by betting procedures
No full textIn this paper, we derive power guarantees of some sequential tests for bounded mean under general alternatives. We focus on testing procedures using nonnegative supermartingales which are anytime valid and consider alternatives which coincide asymptotically with the null (e.g. vanishing mean) while still allowing to reject in finite time. Introducing variance constraints, we show that the alternative can be broaden while keeping power guarantees for certain second-order testing procedures. We also compare different test procedures in multidimensional setting using characteristics of the rejection times. Finally, we extend our analysis to other functionals as well as testing and comparing forecasters. Our results are illustrated with numerical simulations including bounded mean testing and comparison of forecasters
Numerical Analysis of Energy Retrofits Impacts on Indoor Thermal and Air Quality of Single-Family Houses
No full textInternational audienc
(Agri)culture machinique: Esthétisation, mise en scène et représentation du travail agricole mécanisé sur YouTube
No full textNational audience(Agri)culture machiniqueEsthétisation, mise en scène et représentation du travail agricole mécanisé sur YouTube