In situ CCVD synthesis of carbon nanotubes within a commercial ceramic foam

Consolidated nanocomposite foams containing a large quantity of carbon nanotubes (CNTs) within millimetre-sized pores are prepared for the first time. A commercial ceramic foam is impregnated by a 60 g L21 slurry of a (Mg(12x)(Co0.75Mo0.25)xO solid solution (x = 0.01, 0.05, 0.1 and 0.2) powder in ethanol. Three successive impregnations led to deposits several tens of mm thick, with a good coverage of the commercial-ceramic pore walls but without closing the pores. The materials were submitted to a CCVD treatment in H2–CH4 atmosphere in order to synthesise the CNTs. When using attrition-milled powders, the carbon is mostly in the form of nanofibres or disordered carbon rather than CNTs. Using non-milled powders produces a less-compact deposit of catalytic material with a higher adherence to the walls of the ceramic foam. After CCVD, the carbon is mostly in the form of high-quality CNTs, as when using powder beds, their quantity being 2.5 times higher. The so-obtained consolidated nanocomposite materials show a multi-scale pore structuration

Collaborative Knowledge Acquisition under Control of a Non-Regression Test System

14 pagesInternational audienceThis paper introduces BeGoood, a generic system for man- aging non-regression tests on knowledge-bases. BeGoood is a system al- lowing to define test plans in order to monitor the evolution of knowledge- bases. Any system answering queries by providing results in the form of set of strings can be tested with BeGoood. BeGoood has been devel- oped following a REST architecture and is independent of any applica- tion domain. This paper describes the architecture of the system and gives a use case to illustrate how BeGoood is able to manage a collab- orative knowledge evolution in the framework of a case-based reasoning system

Analyses of extreme swell events on La Réunion Island from microseismic noise

International audienceOcean wave activity excites seismic waves that propagate through the solid earth, known as microseisms, which, once recorded on oceanic islands, can be used to analyze the swell. Here, we analyze the microseismic noise recorded in different period ranges by the permanent seismic station RER on La Réunion Island and by a temporary network of ten broad-band seismic stations deployed on the island to analyze extreme swell events. We perform a comparative analysis of cyclonic and austral swell events by analyzing the primary (PM, ∼ 10 to 20 s period) and secondary (SM, ∼ 3 to 10 s) microseisms, but also the long period secondary microseisms (LPSM, ∼ 7 to 10 s), which may result from the interaction between incident ocean waves and the reflected waves off the coast. We compare the microseismic observations with buoy data when available and with predictions from numerical ocean wave models. We show that each cyclone is characterized by its own individual signature in the SM, which depends on its distance and intensity, but also on its dynamics and trajectory. Thus, the SM contains relevant information for cyclone detection and monitoring. Analyzing the PM and the LPSM, and comparing it to direct buoy observations and/or swell numerical models allows characterizing the local impact of the swell with the island in terms of amplitude, period, and sometimes, direction of propagation, making possible to use a seismic station as an ocean wave gauge. The microseisms, which link the atmosphere, the ocean and the solid Earth, can thus provide valuable observations on extreme swells, in addition to oceanic and meteorological data

Man-Machine Collaboration to Acquire Cooking Adaptation Knowledge for the TAAABLE Case-Based Reasoning System

International audienceThis paper shows how humans and machines can better collaborate to acquire adaptation knowledge (AK) in the framework of a case-based reasoning (CBR) system whose knowledge is encoded in a semantic wiki. Automatic processes like the CBR reasoning process itself, or speci c tools for acquiring AK are integrated as wiki extensions. These tools and processes are combined on purpose to collect AK. Users are at the center of our approach, as they are in a classical wiki, but they will now bene t from automatic tools for helping them to feed the wiki. In particular, the CBR system, which is currently only a consumer for the knowledge encoded in the semantic wiki, will also be used for producing knowledge for the wiki. A use case in the domain of cooking is given to exemplify the man-machine collaboration

Tide-induced microseismicity in the Mertz glacier grounding area, East Antarctica

International audienceThe deployment of a seismic network along the Adélie and George V coasts in East Antarctica during the period 2009–2012 provides the opportunity to monitor cryoseismic activity and to obtain new insights on the relationship between tidal cycles and coastal glacier dynamics. Here we focus on records from a seismometer located on a rocky outcrop in the vicinity of the grounding line of the 35 km broad Mertz glacier, a major outflow of this region. We detect numerous icequakes (50,000 events within 10 months and up to 100 events/h) and demonstrate their clear tidal modulation. We suggest that they result from ice friction and fracturing around the rocky peak and from the glacier flexure in response to the falling and rising tides at its grounding area. We propose that such icequake monitoring could be used as a climate proxy since grounding lines are subject to migrate with sea level changes

Extracting Generic Cooking Adaptation Knowledge for the TAAABLE Case-Based Reasoning System

International audienceThis paper addresses the issue of interactive adaptation knowledge acquisition. It shows how the expert's involvement in this process can improve the quality and usefulness of the results. The approach is defended in the context of \taaable, a \cbr system which adapts recipes to user needs. In \taaable, adaptation knowledge takes the form of substitutions. A datamining process allows the discovery of specific substitutions in recipes. A second process, that must be driven by an expert, is needed to generalise these substitutions to make them usable on other recipes. For that, we defend an approach based on closed itemsets (CIs) for extracting generic substitutions starting from specific ones. We focus on a restrictive selection of objects, on a specific filtering on the form of the CIs and on a specific ranking on support and stability of the CIs. Experimentations demonstrate the feasibility of our approach and show some first results

L’archéologie forestière dans le Châtillonnais de la prospection pédestre aux relevés LiDAR

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Knowledge Continuous Integration Process (K-CIP)

International audienceSocial semantic web creates read/write spaces where users and smart agents collaborate to produce knowledge readable by humans and machines. An important issue concerns the ontology evolution and evaluation in man-machine collaboration. How to perform a change on ontologies in a social semantic space that currently uses these ontologies through requests ? In this paper, we propose to implement a continuous knowledge integration process named K-CIP. We take advantage of man-machine collaboration to transform feedback of people into tests. This paper presents how K-CIP can be deployed to allow fruitful man-machine collaboration in the context of the WikiTaaable system.Le web sémantique social crée des espaces partagés dans lesquels des utilisateurs et des agents logiciels collabore pour produire de la connaissance utilisable par les humains et les machines. Un problème important est celui de l'évolution et l'évaluation des ontologies dans la collaboration : comment réaliser un changement sur une ontologie dans un espace qui utilise cette ontologie. Dans ce papier, nous proposons de réaliser un processus d'intégration continue de la connaissance nommé K-CIP. Nous tirons profit des retours des utilisateurs dans la collaboration pour construire des tests. Cet article montre comment K-CIP peut être mis en oeuvre pour améliorer la collaboration humain-machine dans le contexte du système WikiTaaable

WikiTaaable, un wiki sémantique utilisé comme un tableau noir dans un système de raisonnement à partir de cas textuel

National audienceLes wikis sémantiques permettent à des communautés d'utilisateurs de produire des connaissances formalisées compréhensibles et utilisables par les machines. Afin d'aller plus loin, on pourrait imaginer d'utiliser les wikis sémantiques comme des tableaux noirs permettant aux humains et aux machines d'interagir afin de construire des connaissances qui soient à la fois utiles aux humains et aux machines. Dans ce papier, nous présentons une étude de cas portant sur l'utilisation d'un wiki sémantique (connu sous le nom de Semantic Media Wiki) comme un tableau noir pour gérer des données et des connaissances culinaires. Cette étude de cas est réalisée dans le contexte de Taaable, le fameux système de raisonnement à partir de cas en ligne capable de résoudre des problèmes culinaires en utilisant une base de recettes existantes. Avec WikiTaaable, l'évolution de Taaable intégrant un wiki sémantique, nous voulons montrer comment un wiki sémantique peut apporter support et assistance aux utilisateurs chargés des tâches fastidieuses de gestion des connaissances. Nous montrons en particulier comment le wiki facilite la prise en compte du feedback des utilisateurs. Les questions relatives à la présence d'utilisateurs multiples ainsi qu'à l'intégration de plusieurs mécanismes de gestion des connaissances dans une application unique sont discutées à la fin de ce papier

TAAABLE: Text Mining, Ontology Engineering, and Hierarchical Classification for Textual Case-Based Cooking

International audienceThis paper presents how the Taaable project addresses the textual case-based reasoning challenge of the CCC, thanks to a combination of principles, methods, and technologies of various fields of knowledge-based system technologies, namely CBR, ontology engineering manual and semi-automatic), data and text-mining using textual resources of the Web, text annotation (used as an indexing technique), knowledge representation, and hierarchical classification. Indeed, to be able to reason on textual cases, indexing them by a formal representation language using a formal vocabulary has proven to be useful