Un Algorithme génétique spécifique à une reformulation multi-requêtes dans un système de recherche d'information

National audienceCet article présente une approche de reformulation de requête fondée sur l'utilisation combinée de la stratégie d'injection de pertinence et des techniques avancées de l'algorithmique génétique. Nous proposons un processus génétique d'optimisation multi-requêtes amélioré par l'intégration des heuristiques de nichage et adaptation des opérateurs génétiques. L'heuristique de nichage assure une recherche d'information coopérative dans différentes directions de l'espace documentaire. L'intégration de la connaissance à la structure des opérateurs permet d'améliorer les conditions de convergence de l'algorithme. Nous montrons, à l'aide d'expérimentations réalisées sur une collection TREC, l'intérêt de notre approche

Évaluation de la pertinence dans les moteurs de recherche géoréférencés

National audienceLearning to rank documents on a search engine requires relevance judgments. We introduce the results of an innovating study on relevance modeling for local search engines. These search engines present search results on a map or as a list of maps. Each map contains all the attributes of a place (noun, address, phone number, etc). Most of these attributes are links users can click. We model the relevance as the weighted sum of all the clicks on a result. We obtain good results by fixing the same weight for each component of the model. We propose a relative order between clicks to determine the optimal weights.Optimiser le classement des résultats d’un moteur par un algorithme de learning to rank nécessite de connaître des jugements de pertinence entre requêtes et documents. Nous présentons les résultats d’une étude pilote sur la modélisation de la pertinence dans les moteurs de recherche géoréférencés. La particularité de ces moteurs est de présenter les résultats de recherche sous forme de carte géographique ou de liste de fiches. Ces fiches contiennent les caractéristiques du lieu (nom, adresse, téléphone, etc.) dont la plupart sont cliquables par l’utilisateur. Nous modélisons la pertinence comme la somme pondérée des clics sur le résultat. Nous montrons qu’équipondérer les différents éléments du modèle donne de bons résultats et qu’un ordre d’importance entre type de clics peut être déduit pour déterminer les pondérations optimales

Efficacy of European Policies on Rural Landscape: the Case Study of Sardinia (ITALY)

Over the last decades, a large number of developed countries have explicitly recognized the importance of benefits generated from agricultural and rural landscape into their legislation. Since the early '90, preservation and enhancing of rural landscape has played an increasing role also into the Common Agricultural Policy (CAP) promoted by the European Union (EU). More generally, the whole European rural development policy seems to recognize an important role to the keeping of agricultural and rural landscape. The present work is a part of a wider research aimed to identify rational instruments for guidance policies on rural landscape. The specific purpose of this paper is to evaluate efficacy of Sardinian (Italy) regional policies on rural landscape. In particular, the analysis aims to assess "functionality" of policies on rural landscape in programming policy. Results arisen from analysis of Rural Development of this first evaluation are controversial.rural landscape, rural and environmental policies, structural policies, efficacy policies evaluation, Sardinia, Agricultural and Food Policy, Q18, Q28, R59,

Compréhension automatique du geste et de la parole spontanés en communication homme-machine : apport de la théorie de la pertinence

With an approach based on the spontaneous character of man-machine communication, we need to provide multimodal systems with intelligent comprehensive abilities. The design of such systems must rely on theories from social sciences. But these theories have to handle concepts which can be formalized in a computing point of vue. The example we present in this paper with Relevance Theory appears to fit well this concern

Cadre d'évaluation de systèmes de recherche d'information géographique Apport de la combinaison des dimensions spatiale, temporelle et thématique

National audienceCommon search engines process users' queries, i.e., information needs, by extracting terms from documents. Such approaches are limited regarding particular contexts, such as specialized collections (e.g., cultural heritage collections) or specific retrieval criteria (e.g., multidimensional criteria). In this paper, we consider Geographic Information Retrieval Systems (GIRS) exploiting the spatial, temporal, and topical dimensions. Our contribution is twofold as we propose a GIRS evaluation framework for testing the following assumption: combining spatial and temporal dimensions along with the topical dimension improves GIRS effectiveness

CHORUS Deliverable 2.1: State of the Art on Multimedia Search Engines

Based on the information provided by European projects and national initiatives related to multimedia search as well as domains experts that participated in the CHORUS Think-thanks and workshops, this document reports on the state of the art related to multimedia content search from, a technical, and socio-economic perspective. The technical perspective includes an up to date view on content based indexing and retrieval technologies, multimedia search in the context of mobile devices and peer-to-peer networks, and an overview of current evaluation and benchmark inititiatives to measure the performance of multimedia search engines. From a socio-economic perspective we inventorize the impact and legal consequences of these technical advances and point out future directions of research