Laboratoire Hubert Curien

Saint-Étienne, France

Laboratoire Hubert Curien

Saint-Étienne, France

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Singh K.,Fraunhofer Institute for Intelligent Analysis and Information Systems | Both A.,Mercateo AG | Diefenbach D.,Laboratoire Hubert Curien | Shekarpour S.,University of Bonn
Proceedings - 2016 IEEE 10th International Conference on Semantic Computing, ICSC 2016 | Year: 2016

Question answering (QA) is one of the biggest challenges for making sense out of data. The Web of Data has attracted the attention of the QA community and recently, a number of schema-aware QA systems have been introduced. While research achievements are individually significant, yet, integrating different approaches is not possible due to lack of a systematic approach for conceptually describing QA systems. In this paper, we present a message-driven vocabulary built upon an abstract level. This vocabulary is concluded from conceptual views of different QA systems. In this way, we are enabling researchers and industry to implement message-driven QA systems and to reuse and extend different approaches without interoperability and extension concerns. © 2016 IEEE.

Both A.,Mercateo AG | Diefenbach D.,Laboratoire Hubert Curien | Singh K.,Fraunhofer Institute for Intelligent Analysis and Information Systems | Shekarpour S.,University of Bonn | And 2 more authors.
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016

It is very challenging to access the knowledge expressed within (big) data sets. Question answering (QA) aims at making sense out of data via a simple-to-use interface. However, QA systems are very complex and earlier approaches are mostly singular and monolithic implementations for QA in specific domains. Therefore, it is cumbersome and inefficient to design and implement new or improved approaches, in particular as many components are not reusable. Hence, there is a strong need for enabling best-of-breed QA systems, where the best performing components are combined, aiming at the best quality achievable in the given domain. Taking into account the high variety of functionality that might be of use within a QA system and therefore reused in new QA systems, we provide an approach driven by a core QA vocabulary that is aligned to existing, powerful ontologies provided by domain-specific communities.We achieve this by a methodology for binding existing vocabularies to our core QA vocabulary without recreating the information provided by external components. We thus provide a practical approach for rapidly establishing new (domain-specific) QA systems, while the core QA vocabulary is re-usable across multiple domains. To the best of our knowledge, this is the first approach to open QA systems that is agnostic to implementation details and that inherently follows the linked data principles. © Springer International Publishing Switzerland 2016.

Ziko I.M.,Laboratoire Hubert Curien | Fromont E.,Laboratoire Hubert Curien | Muselet D.,Laboratoire Hubert Curien | Sebban M.,Laboratoire Hubert Curien
Proceedings - 3rd IAPR Asian Conference on Pattern Recognition, ACPR 2015 | Year: 2015

When building traditional Bag of Visual Words (BOW) for image classification, the K-means algorithm is usually used on a large set of high dimensional local descriptors to build the visual dictionary. However, it is very likely that, to find a good visual vocabulary, only a sub-part of the descriptor space of each visual word is truly relevant. We propose a novel framework for creating the visual dictionary based on a spectral subspace clustering method instead of the traditional K-means algorithm. A strategy for adding supervised information during the subspace clustering process is formulated to obtain more discriminative visual words. Experimental results on real world image dataset show that the proposed framework for dictionary creation improves the classification accuracy compared to using traditionally built BOW. © 2015 IEEE.

Gouiffes M.,University Paris - Sud | Collewet C.,French Institute for Research in Computer Science and Automation | Fernandez-Maloigne C.,University of Poitiers | Tremeau A.,Laboratoire Hubert Curien
Computer Vision and Image Understanding | Year: 2012

Since modeling reflections in image processing is a difficult task, most computer vision algorithms assume that objects are Lambertian and that no lighting change occurs. Some photometric models can partly answer this issue by assuming that the lighting changes are the same at each point of a small window of interest. Through a study based on specular reflection models, we explicit the assumptions on which these models are implicitly based and the situations in which they could fail. This paper proposes two photometric models, which compensate for specular highlights and lighting variations. They assume that photometric changes vary smoothly on the window of interest. Contrary to classical models, the characteristics of the object surface and the lighting changes can vary in the area being observed. First, we study the validity of these models with respect to the acquisition setup: relative locations between the light source, the sensor and the object as well as the roughness of the surface. Then, these models are used to improve feature points tracking by simultaneously estimating the photometric and geometric changes. The proposed methods are compared to well-known tracking methods robust to affine photometric changes. Experimental results on specular objects demonstrate the robustness of our approaches to specular highlights and lighting changes. © 2012 Elsevier Inc. All rights reserved.

Belaud V.,École Centrale Lyon | Valette S.,École Centrale Lyon | Stremsdoerfer G.,École Centrale Lyon | Beaugiraud B.,École Centrale Lyon | And 2 more authors.
Scanning | Year: 2014

We have investigated femtosecond (fs) laser (130-fs, 800-nm, 5-kHz) ablation of polypropylene (PP). The following laser process conditions were varied: power density and number of pulses. The morphological parameters' response (depth, ablation diameter, ablation volume) to the laser process conditions, measured by an optical profiler, was investigated by the statistical analysis technique to determine the relationship between them. For this, the simple linear regression and the multiple linear regressions are compared. The simple linear regression shows that the ablation volume follows a linear relationship with the product of the power and the number of pulse. © 2014 Wiley Periodicals, Inc.

Subercaze J.,Laboratoire Hubert Curien | Maret P.,Laboratoire Hubert Curien
Studies in Computational Intelligence | Year: 2011

At the beginning of the decade, the Agent Mediated Knowledge Management workshops series as well as Bonifacio's theoretical approach layed the foundations of a new eld of distributed knowledge management based upon the agent paradigm. The agent based approach enables key features for knowledge management. The local management of knowledge by agents allows to go beyond the limitations of centralized knowledge management. Thus, knowledge can be maintained in each agent at a coarse-grained level, with different representations. In the mean time the rise of the semantic web technologies enables a new range of possibilities for agents dedicated to knowledge management. In this chapter we investigate the integration of semantic web technologies into an agent architecture that allows agents to represent their knowledge and their behavior in a semantic manner. We present the semantic agent model, its implementation and we discuss the perpectives open by semantic agents. © 2011 Springer-Verlag Berlin Heidelberg.

Povarnitsyn M.E.,Moscow Institute of Physics and Technology | Itina T.E.,Laboratoire Hubert Curien | Levashov P.R.,Moscow Institute of Physics and Technology | Khishchenko K.V.,Moscow Institute of Physics and Technology
Physical Chemistry Chemical Physics | Year: 2013

Laser ablation in liquids is now commonly used to produce colloidal nanoparticles (NPs) that have found numerous applications in different areas. In experiments, NPs of different materials can be rather easily obtained by using laser systems with various pulse durations, shapes, wavelengths, and fluences. In this paper, we focus our attention on metal (gold) NPs produced by ultra-short laser pulses. To better understand the mechanisms of the NPs formation, we perform modeling of femtosecond laser interactions with a gold target in the presence of liquid (water). Simulation of the ablation process over several nanoseconds shows that most of the primary NPs originate from the ablated metastable liquid layer, whereas only a minority is formed by condensation inside the cavitation bubble. These particles will further grow/evaporate, and coagulate during a much longer collision stage in the liquid colloid. This journal is © 2013 the Owner Societies.

Lachheb S.,C2MFF | Colantoni P.,C2MFF | Dinet E.,Laboratoire Hubert Curien
5th European Conference on Colour in Graphics, Imaging, and Vision and 12th International Symposium on Multispectral Colour Science 2010, CGIV 2010/MCS'10 | Year: 2010

A set of colours aesthetically pleasant are described as harmonious in the language of human visual perception. As this notion encloses a subjective part, a psychophysical experiment was carried out to estimate the perception of colour harmony for combinations of paintings with the uniform colour of walls on which they are hung. The experiment, that involved 38 observers, was based on accurate colours built upon a specific colour flow. Participants were asked to judge the colour harmony of combinations of a sample of 7 selected paintings with backgrounds uniformly coloured in 3 different ranges of colours - achromatic colours, tones derived from the global average colour of the considered painting and tones derived from the complementary of the global average colour of the considered painting. Results demonstrate that the best colour harmony is obtained when the average colour of paintings is used to colour their background. The experiment presented in this paper clearly shows that the white colour usually used for walls in museums does not optimize the colour harmony.

Farrahi K.,Goldsmiths, University of London | Emonet R.,Laboratoire Hubert Curien | Cebrian M.,Massachusetts Institute of Technology | Cebrian M.,University of California at San Diego
PLoS ONE | Year: 2014

Traditional contact tracing relies on knowledge of the interpersonal network of physical interactions, where contagious outbreaks propagate. However, due to privacy constraints and noisy data assimilation, this network is generally difficult to reconstruct accurately. Communication traces obtained by mobile phones are known to be good proxies for the physical interaction network, and they may provide a valuable tool for contact tracing. Motivated by this assumption, we propose a model for contact tracing, where an infection is spreading in the physical interpersonal network, which can never be fully recovered; and contact tracing is occurring in a communication network which acts as a proxy for the first. We apply this dual model to a dataset covering 72 students over a 9 month period, for which both the physical interactions as well as the mobile communication traces are known. Our results suggest that a wide range of contact tracing strategies may significantly reduce the final size of the epidemic, by mainly affecting its peak of incidence. However, we find that for low overlap between the face-to-face and communication interaction network, contact tracing is only efficient at the beginning of the outbreak, due to rapidly increasing costs as the epidemic evolves. Overall, contact tracing via mobile phone communication traces may be a viable option to arrest contagious outbreaks. © 2014 Farrahi et al.

Dubosclard P.,Hoffmann-La Roche | Dubosclard P.,Toulouse 1 University Capitole | Larnier S.,Hoffmann-La Roche | Larnier S.,Toulouse 1 University Capitole | And 5 more authors.
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2014

This paper presents an automatic method for visual grading, designed to solve the industrial problem of evaluation of seed lots. The sample is thrown in bulk onto a tray placed in a chamber for acquiring color image. An image processing method had been developed to separate and characterize each seed. The approach adopted for the segmentation step is based on the use of marked point processes and active contour, leading to tackle the problem by a technique of energy minimization. © Springer International Publishing Switzerland 2014.

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