Search results for "Data mining"
showing 10 items of 907 documents
Architectural Reconstruction of 3D Building Objects through Semantic Knowledge Management
2010
International audience; This paper presents an ongoing research which aims at combining geometrical analysis of point clouds and semantic rules to detect 3D building objects. Firstly by applying a previous semantic formalization investigation, we propose a classification of related knowledge as definition, partial knowledge and ambiguous knowledge to facilitate the understanding and design. Secondly an empirical implementation is conducted on a simplified building prototype complying with the IFC standard. The generation of empirical knowledge rules is revealed and semantic scopes are addressed both in the bottom up manner along the line of geometry --> topology --> semantic, and a vice ver…
Automated uncertainty quantification analysis using a system model and data
2015
International audience; Understanding the sources of, and quantifying the magnitude of, uncertainty can improve decision-making and, thereby, make manufacturing systems more efficient. Achieving this goal requires knowledge in two separate domains: data science and manufacturing. In this paper, we focus on quantifying uncertainty, usually called uncertainty quantification (UQ). More specifically, we propose a methodology to perform UQ automatically using Bayesian networks (BN) constructed from three types of sources: a descriptive system model, physics-based mathematical models, and data. The system model is a high-level model describing the system and its parameters; we develop this model …
Mixed Driven Refinement Design of Multidimensional Models based on Agglomerative Hierarchical Clustering
2015
20 pages; International audience; Data warehouses (DW) and OLAP systems are business intelligence technologies allowing the on-line analysis of huge volume of data according to users' needs. The success of DW projects essentially depends on the design phase where functional requirements meet data sources (mixed design methodology) (Phipps and Davis, 2002). However, when dealing with complex applications existing design methodologies seem inefficient since decision-makers define functional requirements that cannot be deduced from data sources (data driven approach) and/or they have not sufficient application domain knowledge (user driven approach) (Sautot et al., 2014b). Therefore, in this p…
Simplification d’un modèle complexe pour le développement d’un modèle d’aide à la décision pour la gestion agroécologique de la flore adventice
2019
National audience; Afin de réduire l’utilisation d’herbicides, nous avons besoin de nouveaux outils pour aider à concevoir des stratégies de gestion des adventices économes en herbicides. Dans ce but, nous avons développé un Outil d'Aide à la Décision (OAD) pour la conception de systèmes de culture réconciliant protection des cultures et respect des écosystèmes. La démarche fait intervenir en parallèle le développement de la structure de l’outil en interaction avec les futurs utilisateurs (conseillers et agriculteurs) et une sim-plification du contenu biophysique du modèle FLORSYS concernant les impacts des systèmes de culture et des adventices. FLORSYS est une « parcelle virtuelle », où so…
Co-développement d'un modèle d'aide à la décision pour la gestion intégrée de la flore adventice. Méta-modélisation et analyse de sensibilité d'un mo…
2018
The main threat to agricultural crops are weeds with herbicides being the primary cropping management practice. Due to the negative impact of herbicides on health and environment, their use must be reduced. To replace herbicides, numerous cropping practices need to be implemented. This makes weed management more complicated and, together with necessity of scheduling operations at long-term and the multiplicity of cropping system impacts, explains why models are so useful for designing innovative cropping systems. The aim of this thesis was to develop a Decision Support System (DSS) intended for crop advisors to help design cropping systems that are less dependent on herbicides. Our approach…
A multiple-response chi-square framework for the analysis of Free-Comment and Check-All-That-Apply data
2021
International audience; Free-Comment (FC) and Check-All-That-Apply (CATA) provide a contingency table containing citation counts of descriptors by products. The analyses performed on this table are most often related to the chi-square statistic. However, such practices are not well suited because they consider experimental units as being the citations (one descriptor for one product by one subject) while the evaluations (vector of citations for one product by one subject) should be considered instead. This results in incorrect expected frequencies under the null hypothesis of independence between products and descriptors and thus in an incorrect chi-square statistic. Thus, analyses related …
New technologies can support data collection on endangered shark species in the Mediterranean Sea
2022
In the last 50 yr, shark populations showed steep declines in the Mediterranean Sea. The IUCN lists most Mediterranean species as threatened (55%), while considering 27.5% of them Data Deficient. Here, sharks are currently one of the rarest and more elusive groups of animals, and data from fisheries and scientific monitoring still insufficiently support robust abundance and distribution assessments. New technologies can fill this data gap by linking people and scientists through new monitoring strategies. SharkPulse, an international collaborative project, aims at creating a large world database of shark occurrence records by mining images on the web, social networks, and private archives. …
Geostatistical computing of acoustic maps in the presence of barriers
2009
Acoustic maps are the main diagnostic tools used by authorities for addressing the growing problem of urban acoustic contamination. Geostatistics models phenomena with spatial variation, but restricted to homogeneous prediction regions. The presence of barriers such as buildings introduces discontinuities in prediction areas. In this paper we investigate how to incorporate information of a geographical nature into the process of geostatistical prediction. In addition, we study the use of a Cost-Based distance to quantify the correlation between locations.
"Co-development of a decision support model for integrated weed management. Metamodelling and sensitivity analysis of a complex mechanistic model (FL…
2018
In order to reduce our use ofherbicides, we need a tool to design weedmanagement strategies relying on fewerherbicides. Weed management is complicatedand, together with necessity of schedulingoperations at long-term and the multiplicity ofcropping system impacts, it explains whymodels are so useful for designing innovativecropping systems. The aim of this thesis is todevelop a decision support system, intended forcrop advisors, reconciling crop protection andecosystem services Our approach consisted inidentifying the structure of the DSS ininteraction with future users while using anexisting research model, FLORSYS, for thebiophysical content of the tool. FLORSYS is a“virtual field” simulat…
Anomaly Detection and Classification of Household Electricity Data : A Time Window and Multilayer Hierarchical Network Approach
2022
With the increasing popularity of the smart grid, huge volumes of data are gathered from numerous sensors. How to classify, store, and analyze massive datasets to facilitate the development of the smart grid has recently attracted much attention. In particular, with the popularity of household smart meters and electricity monitoring sensors, a large amount of data can be obtained to analyze household electricity usage so as to better diagnose the leakage and theft behaviors, identify man-made tampering and data fraud, and detect powerline loss. In this paper, the time window method is first proposed to obtain the features and potential periodicity of household electricity data. Combining th…