34 research outputs found
Learning Probabilistic Relational Models using an Ontology of Transformation Processes
No full textInternational audienceProbabilistic Relational Models (PRMs) extend Bayesian networks (BNs) with the notion of class of relational databases. Because of their richness, learning them is a difficult task. In this paper, we propose a method that learns a PRM from data using the semantic knowledge of an ontology describing these data in order to make the learning easier. To present our approach, we describe an implementation based on an on-tology of transformation processes and compare its performance to that of a method that learns a PRM directly from data. We show that, even with small datasets, our approach of learning a PRM using an ontology is more efficient
Haptic rendering of interacting dynamic deformable objects simulated in real-time at different frequencies
No full textRadial and nonradial static efficiency decompositions: a focus on congestion measurement
No full textWe summarize and extend the existing frontier literature by outlining proper ways of decomposing efficiency using both radial and nonradial efficiency measures when using nonparametric, deterministic frontier models. Our contribution relates to a recent paper of Viton (Transportation Research-B 31, 23-39, 1997) analysing the efficiency of U.S. multi-mode bus transit systems. In particular, the author evaluates the technical efficiency, congestion and scale properties of these companies. Due to a methodological mistake he could not detect congestion in his sample. Our proposals remedy this problem and focus on the underexplored issue of proper congestion measurement in general and in transport in particular.
Radial and nonradial static efficiency decompositions: A focus on congestion measurement
No full textWe summarize and extend the existing frontier literature by outlining proper ways of decomposing efficiency using both radial and nonradial efficiency measures when using nonparametric, deterministic frontier models. Our contribution relates to a recent paper of Viton (Transportation Research-B 31, 23-39, 1997) analysing the efficiency of U.S. multi-mode bus transit systems. In particular, the author evaluates the technical efficiency, congestion and scale properties of these companies. Due to a methodological mistake he could not detect congestion in his sample. Our proposals remedy this problem and focus on the under-explored issue of proper congestion measurement in general and in transport in particular. (C) 1998 Elsevier Science Ltd. All rights reserved
Vers la publication d’une RTO dédiée à l’annotation de relations n-aires.
No full textComité de sélection - audience nationaleComité de sélection - audience nationaleNous présentons dans cet article la modélisation d’une RTO dédiée à latâche d’annotation de relations n-aires, qui permettent de représenter des résultatsexpérimentaux, et un corpus de tableaux annotés avec cette RTO. Nous souhaite-rions pouvoir publier cette RTO et le corpus de tableaux associés sur le Web dedonnées, mais de nombreuses questions se posent. Nous espérons que notre parti-cipation à l’atelier Ontologies et Jeux de Données pour évaluer le web sémantique(OJD) nous aidera à y répondr
Semi-automatic loading of a microbial risk in food database thanks to an ontology in the context of linked data
No full textInternational audienceA preliminary step in microbial risk assessment in food is to gather and to capitalize experimental data in order to feed simulation models. We have designed, in the predictive modeling platform Sym'Previus (www.symprevius.org), a relational database, MicroRisk-RDB [1], to store experimental data in microbial risk. Data capitalization task encounters a challenging lock. Indeed, original data are spread out in heterogeneous data sources (scientific papers, technical reports / sheets, PhD thesis ...). Moreover, they are expressed in heterogeneous formats (mainly tables, text and graphics) and vocabularies. Manual entering of data in a database (e.g. MicroRisk-RDB) is therefore a time-consuming task. We present in this paper methods and tools to facilitate data capitalization and reusability in the framework of the Linked Data initiative , which promotes the publication and connection of structured data on the Web
Semi-automatic loading of a microbial risk in food database thanks to an ontology in the context of linked data
No full textInternational audienceA preliminary step in microbial risk assessment in food is to gather and to capitalize experimental data in order to feed simulation models. We have designed, in the predictive modeling platform Sym'Previus (www.symprevius.org), a relational database, MicroRisk-RDB [1], to store experimental data in microbial risk. Data capitalization task encounters a challenging lock. Indeed, original data are spread out in heterogeneous data sources (scientific papers, technical reports / sheets, PhD thesis ...). Moreover, they are expressed in heterogeneous formats (mainly tables, text and graphics) and vocabularies. Manual entering of data in a database (e.g. MicroRisk-RDB) is therefore a time-consuming task. We present in this paper methods and tools to facilitate data capitalization and reusability in the framework of the Linked Data initiative , which promotes the publication and connection of structured data on the Web
Vers la publication d’une RTO dédiée à l’annotation de relations n-aires.
No full textComité de sélection - audience nationaleComité de sélection - audience nationaleNous présentons dans cet article la modélisation d’une RTO dédiée à latâche d’annotation de relations n-aires, qui permettent de représenter des résultatsexpérimentaux, et un corpus de tableaux annotés avec cette RTO. Nous souhaite-rions pouvoir publier cette RTO et le corpus de tableaux associés sur le Web dedonnées, mais de nombreuses questions se posent. Nous espérons que notre parti-cipation à l’atelier Ontologies et Jeux de Données pour évaluer le web sémantique(OJD) nous aidera à y répondr
Vers la publication d’une RTO dédiée à l’annotation de relations n-aires.
No full textComité de sélection - audience nationaleComité de sélection - audience nationaleNous présentons dans cet article la modélisation d’une RTO dédiée à latâche d’annotation de relations n-aires, qui permettent de représenter des résultatsexpérimentaux, et un corpus de tableaux annotés avec cette RTO. Nous souhaite-rions pouvoir publier cette RTO et le corpus de tableaux associés sur le Web dedonnées, mais de nombreuses questions se posent. Nous espérons que notre parti-cipation à l’atelier Ontologies et Jeux de Données pour évaluer le web sémantique(OJD) nous aidera à y répondr
A decision making platform for risk-benefit analysis of foods
No full textComité de sélection - audience internationaleComité de sélection - audience internationaleabsen
