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Conception of a dominance-based multi-objective local search in the context of classification rule mining in large and imbalanced data sets
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On spatial conditional quantile estimation for a functional regressor
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Graph Data Exchange with Target Constraints
No full textInternational audienceData exchange is the problem of translating data structured under a source schema according to a target schema and a set of source-to-target constraints known as schema mappings. In this paper, we investigate the problem of data exchange in a heterogeneous setting, where the source is a relational database, the target is a graph database, and the schema mappings are defined across them. We study the classical problems considered in data exchange, namely the existence of solutions and query answering. We show that both problems are intractable in the presence of target constraints, already under significant restrictions
Towards a heterogeneous and adaptive parallel Branch-and-Bound algorithm
No full textInternational audienceIn this work, we revisit the design and implementation of the Branch-and-Bound (B&B) algorithm for heterogeneous environments combining multi-core processors with GPU accelerators. The challenge is to automatically identify the best mapping of computations to the target heterogeneous platform and to adjust the problem, algorithmic and platform parameters. In the proposed meta-algorithm, four hardware configuration scenarios have been considered: 1CPU-1GPU, nCPU-0GPU, nCPU-1GPU, nCPU-nGPU.Over a serial B&B, accelerations up to ×222 have been achieved for large problem instances of the Flow-Shop scheduling problem. The reported results show that: (1) the GPU-accelerated algorithm performs better than its multi-core CPU-based version; (2) combining multi-core and GPU allows improvement up to 36% over a single CPU-GPU execution; (3) the more GPU devices are used, the better the speedups are whatever is the considered problem instance
Lipid signature of the microbial community structure during composting of date palm waste alone or mixed with couch grass clippings
No full textInternational audienceThe content of total lipids and fatty-acid methyl esters (FAMEs) identified by GC MS analysis was followed during composting of date palm waste (DPW) alone or mixed with couch-grass clippings (DPGC). The DPGC compost contained more fats and FAMEs (FAs) than did the DPW compost. Total lipid content decreased during both composting processes with an increase towards the end of DPW composting. The initial fatty acid composition in both composts showed that the DPGC mixture was richer in microbial biomass than the DPW compost. The lignocellulose nature of the date palm substrate probably obstructed the proliferation and development of a broad category of microbial biomass. The appearance of a series of odd-numbered carbon and branched FAMEs was recorded only toward the end of DPW composting. This confirms the low level of biodegradation of date palm substrate rich in substrates that presented difficult access to micro-organisms, as confirmed by a slower degradation. DPW compost required longer to reach similar maturity to DPGC that of the mixture. Calculating the relationship between the various bacterial groups showed that bacteria strongly prevailed over fungi during both DPW and DPGC composting. The follow-up of these ratios in both composts showed that the stabilization phase was not complete in DPGC compost, but that it reached a very advanced stage during DPGC composting after the 8-month trial. An increase in G(+)/G(-) and G(+)/fungus ratios toward the end of DPW composting indicated that composting had just started in the DPW. The variations in the levels of the different steroid compounds identified in the two composts showed that dehydration was stronger in the DPGC mixture than in DPW. An increase of the level of stigmastanol acetate (24-ethylcholestanol), methyl cholestadiene (campestadienes), and cholestanol acetate (cholestanol) in DPGC compost suggests the stimulation of microbial organisms and/or micro-fauna capable of performing the hydrogenation of the corresponding sterols. This microbial activity fluctuated during DPW composting following the bioavailability of substrate that was steadily degraded. The appearance of stigmastadienone toward the end of DPW composting confirmed that composting had just started after the full 8 months
Vers un système d'orchestration adaptatif et collaboratif des activités d'apprentissage en mobilité
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Introducing FoxPersonTracks: A benchmark for person re-identification from TV broadcast shows
No full textInternational audienceThis paper introduces a novel person track dataset dedicated to person re-identification. The dataset is built from a set of real life TV shows broadcasted from BFMTV and LCP TV french channels, provided during REPERE challenge. It contains a total 4,604 persontracks (short video sequences featuring an individual with no background) from 266 persons. The dataset has been built from the REPERE dataset by following several automated processing and manual selection/filtering steps. It is meant to serve as a benchmark in person re-identification from images/videos. The dataset also provides re-identifications results using space-time histograms as a baseline, together with an evaluation tool in order to ease the comparison to other re-identification methods
On-the-fly Diagnosability Analysis of Labeled Petri Nets Using Minimal Explanations
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