Search results for " Retrieval"
showing 10 items of 1114 documents
Détection de précurseurs d'évènements basés sur les motifs dans les réseaux sociaux
2021
Les données issues des réseaux sociaux suscitent l'intérêt des chercheurs qui développent des algorithmes et des modèles d'apprentissage automatique pour analyser les interactions et les comportements des utilisateurs. Ces méthodes s'appuient sur la topologie du réseau pour représenter les changements structurels et pour détecter des précurseurs remarquables précédant généralement des évènements majeurs. L'étude présentée dans cet article vise à étudier si certains graphlets (motifs spécifiques) peuvent être considérés comme des précurseurs d'évènements. Nous expérimentons la méthode proposée sur trois ensembles de données de réseaux sociaux. Nous étudions également le rôle joué dans les gr…
Temporal Semantic Centrality for the Analysis of Communication Networks
2012
National audience; De nos jours, la compréhension des communautés en ligne devient un enjeu majeur du Web. Dans cet article nous proposons une nouvelle mesure, la Probabilité de Propagation Sémantique (SPP), qui caractérise la capacité de l'utilisateur à propager un concept sémantique à d'autres utilisateurs, d'une manière rapide et ciblée. La sémantique des messages est analysée selon une ontologie donnée. Nous utilisons cette mesure pour obtenir la Centralité Sémantique Temporelle (TSC) d'un utilisateur dans une communauté. Nous proposons et évaluons une expérimentation de cette mesure, en utilisant une ontologie et des données réelles issues du Web.
Context-aware semantic Web service discovery protocol
2009
The Web of today represents a broad space where users research, discover and share information. In this context, the process of Web service discovery plays a significant role. Indeed, such process allows linking the information published by service providers and the requests of users, looking for information. Generally, such process involves text or keyword-based techniques. Still, this kind of discovery fails in retrieving only relevant information. Our approach is to design a more " intelligent " system that allows using a knowledge base during the service discovery process, as it is done in the Semantic Web vision. This thesis presents a framework for semantic Web service discovery using…
Towards human exploration of space: the THESEUS review series on cardiovascular, respiratory, and renal research priorities
2016
International audience; The THESEUS project (Towards Human Exploration of Space: aEUropean Strategy) was initiated within the seventh FrameworkProgramme by the European Commission. This project aimed toprovide a cross-cutting, life science-based roadmap for Europe’sstrategy towards human exploration of space, especially for deepspace missions and its relevance to applications on Earth. Toaddress these challenges, relevance of space research on thecardiovascular system, the lungs and kidneys, was discussed in anexpert group and its principal conclusions will be presented in thisarticle.
Carbonated Inheritance in the Eastern Tibetan Lithospheric Mantle: Petrological Evidences and Geodynamic Implications
2020
International audience; The timing and mechanism of formation of the Tibet Plateau remain elusive, and even the present-day structure of the Tibetan lithosphere is hardly resolved, due to conflicting interpretations of the geophysical data. We show here that significant advances in our understanding of this orogeny could be achieved through a better assessment of the composition and rheological properties of the deepest parts of the Tibetan lithosphere, leading in particular to a reinterpretation of the global tomographic cross sections. We report mantle phlogopite xenocrysts and carbonate-bearing ultramafic cumulates preserved in Eocene potassic rocks from the Eastern Qiangtang terrane, wh…
Pop-Up Windows and Information Retrieval
1997
Communication affichée; International audience; Paralinguistics organizers such as parenthesis, footnotes, and pop-up fields on screen, should play an important role signalling the writer's “minimization” intention when secondary points are concerned. This experiment investigated the role of pop-up fields compared to brackets in an information retrieval task. The results showed that, in this kind of task, putting secondary pieces of information into pop-up fields significantly speeded the search process compared to a condition in which the same information was displayed in brackets.
Developing a framework for designing humanitarian blockchain projects
2021
International audience; Blockchain technology promises to improve the efficiency, transparency, and accountability of humanitarian operations. Yet at the same time, especially the humanitarian context with its characteristic volatility poses unique challenges to any technology. Most prominent are the humanitarian principles that are fundamental to humanitarian operations. These ethical principles are set to protect the most vulnerable populations. Designing blockchain projects in the humanitarian context therefore requires a systematic framework that helps humanitarians make critical choices.While some design instructions can be found for commercial applications, the humanitarian context re…
Blockchain Disrupting Fintech and the Banking System
2021
Nowadays society is profoundly changed by technology, velocity and productivity. While individuals are not yet prepared for holographic connection with banks or financial institutions, other innovative technologies have been adopted. Lately, a new world has been launched, personalized and adapted to reality. It has emerged and started to govern almost all daily activities due to the five key elements that are foundations of the technology: machine to machine (M2M), internet of things (IoT), big data, machine learning and artificial intelligence (AI). Competitive innovations are now on the market, helping with the connection between investors and borrowers—notably crowdfunding and peer-to-pe…
A sun-induced vegetation fluorescence retrieval method from top of atmosphere radiance for the FLEX/Sentinel-3 TanDEM mission
2015
A new fluorescence retrieval method is proposed to support ESA's 8th Earth Explorer FLuorescence EXplorer/Sentinel-3 (FLEX-S3) candidate tandem mission. FLEX is the first mission specially dedicated to measure the Sun-Induced vegetation chlorophyll fluorescence (SIF) strongly related with the vegetation photosynthetic activity. Most hyperspectral fluorescence retrieval algorithms available in the literature are very sensitive to true reflectance modelization and/or they assume the atmospheric status as known. The proposed algorithm delivers the retrieval of full fluorescence spectrum at canopy level by using only Top Of Atmosphere (TOA) radiances from S3 and FLEX as input. Once the spatial …
Modeling user preferences in content-based image retrieval: A novel attempt to bridge the semantic gap
2015
This paper is concerned with content-based image retrieval from a stochastic point of view. The semantic gap problem is addressed in two ways. First, a dimensional reduction is applied using the (pre-calculated) distances among images. The dimension of the reduced vector is the number of preferences that we allow the user to choose from, in this case, three levels. Second, the conditional probability distribution of the random user preference, given this reduced feature vector, is modeled using a proportional odds model. A new model is fitted at each iteration. The score used to rank the image database is based on the estimated probability function of the random preference. Additionally, so…