CNRS Research Institute of Communication and Cybernetics of Nantes

Nantes, France

CNRS Research Institute of Communication and Cybernetics of Nantes

Nantes, France
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Califano C.,University of Rome La Sapienza | Moog C.H.,CNRS Research Institute of Communication and Cybernetics of Nantes
IEEE Transactions on Automatic Control | Year: 2017

A full characterization of accessibility is provided for nonlinear time-delay systems. It generalizes the rank condition which is known for weak controllability of linear time-delay systems, as well as the celebrated geometric approach for delay-free nonlinear systems and the characterization of their accessibility. Besides, fundamental results are derived on integrability and basis completion which are of major importance for a number of general control problems for nonlinear time-delay systems. They are shown to impact preconceived ideas about canonical forms for nonlinear time-delay systems. © 2016 IEEE.


Fevotte C.,Orange S.A. | Idier J.,CNRS Research Institute of Communication and Cybernetics of Nantes
Neural Computation | Year: 2011

QAbThis letter describes algorithms for nonnegative matrix factorization (NMF) with the β-divergence (β-NMF). The β-divergence is a family of cost functions parameterized by a single shape parameter β that takes the Euclidean distance, the Kullback-Leibler divergence, and the Itakura-Saito divergence as special cases (β = 2, 1, 0 respectively). The proposed algorithms are based on a surrogate auxiliary function (a local majorization of the criterion function). We first describe a majorizationminimization algorithm that leads to multiplicative updates, which differ from standard heuristic multiplicative updates by a β-dependent power exponent. The monotonicity of the heuristic algorithm can, however, be proven for β ∈ (0, 1) using the proposed auxiliary function. Thenweintroduce the concept of the majorization-equalization (ME) algorithm, which produces updates that move along constant level sets of the auxiliary function and lead to larger steps than MM. Simulations on synthetic and real data illustrate the faster convergence of the ME approach. The letter also describes how the proposed algorithms can be adapted to two common variants of NMF: penalized NMF (when a penalty function of the factors is added to the criterion function) and convex NMF (when the dictionary is assumed to belong to a known subspace).


Orlov Y.,CICESE | Aoustin Y.,CNRS Research Institute of Communication and Cybernetics of Nantes | Chevallereau C.,CNRS Research Institute of Communication and Cybernetics of Nantes
IEEE Transactions on Automatic Control | Year: 2011

The twisting and supertwisting algorithms, generating important classes of second order sliding modes (SOSMs), are well-recognized for their finite time stability and robustness properties. In the present paper, a continuous modification of the twisting algorithm and an inhomogeneous perturbation of the supertwisting algorithm are introduced to extend the class of SOSM's that present the afore-mentioned attractive features. Thus modified, the twisting and supertwisting algorithms are utilized in the state feedback synthesis and, respectively, velocity observer design, made for the finite time stabilization of a double integrator if only output measurements are available. Performance and robustness issues of the resulting output feedback synthesis are illustrated by means of numerical simulations. © 2006 IEEE.


Carfantan H.,Toulouse 1 University Capitole | Idier J.,CNRS Research Institute of Communication and Cybernetics of Nantes
IEEE Transactions on Geoscience and Remote Sensing | Year: 2010

This paper introduces a new self-calibration destriping technique for pushbroom-type satellite imaging systems. Selfcalibration means that no specific training data are required. It is based on the statistical estimation of each detector gain from the observed image, assuming a linear response. Both theoretical and practical behaviors are studied. Our technique is shown to outperform simpler techniques based on column averages in terms of gain estimation precision while keeping the computational cost within admissible limits. © 2009 IEEE.


Shahzad A.,CNRS Research Institute of Communication and Cybernetics of Nantes | Mebarki N.,CNRS Research Institute of Communication and Cybernetics of Nantes
Engineering Applications of Artificial Intelligence | Year: 2012

A data mining based approach to discover previously unknown priority dispatching rules for job shop scheduling problem is presented. This approach is based on seeking the knowledge that is assumed to be embedded in the efficient solutions provided by the optimization module built using tabu search. The objective is to discover the scheduling concepts using data mining and hence to obtain a set of rules capable of approximating the efficient solutions for a job shop scheduling problem (JSSP). A data mining based scheduling framework is presented and implemented for a job shop problem with maximum lateness as the scheduling objective. © 2012 Elsevier Ltd. All rights reserved.


Lu W.,CNRS Research Institute of Communication and Cybernetics of Nantes | Petiot J.-F.,CNRS Research Institute of Communication and Cybernetics of Nantes
International Journal of Industrial Ergonomics | Year: 2014

The measurement and understanding of user emotions elicited by product appearance are critical elements of the product development process. This paper proposes a new emotion measurement method, called Auditory Parameter Method. It is a non-verbal technique that uses auditory stimuli (music samples) and association tests for evaluating a set of products, given by their pictures. From user-tests, it provides an assessment of these products according to a series of emotional dimensions. We present the methodological framework used to build the links between user's emotional responses and geometrical features of the products. The method is described on an application case, an eyeglass frame. Analysis of Variance models are employed to examine how various shape factors influence users' emotional responses. To demonstrate the effectiveness of our protocol, we compare the proposed method with the conventional Semantic Differential using Principal Component Analysis and Generalized Procrustes Analysis. The new protocol demonstrates interesting qualities for collecting the intuitive emotions of users and for providing a discriminant measurement of emotions. It can also be used by designers to stimulate creativity. Relevance to industry: This study presents a methodology to the integration of emotional qualities in the design of products, which taking into account the cognitive and affective processing of users. This very innovative emotion assessment method incorporates the modality of sound, thus complementing research in the field which so far focused on the modality of sight. The design knowledge gained from this method, like the semantic mappings and the interpretation of design attributes, makes it possible to benefit the activity of the designers as a creativity support tool. © 2014 Elsevier B.V.


Masson R.,CNRS Research Institute of Communication and Cybernetics of Nantes | Lehuede F.,CNRS Research Institute of Communication and Cybernetics of Nantes | Peton O.,CNRS Research Institute of Communication and Cybernetics of Nantes
Computers and Operations Research | Year: 2014

The Dial-A-Ride Problem with Transfers (DARPT) consists in defining a set of routes that satisfy transportation requests of users between a set of pickup points and a set of delivery points, in the presence of ride time constraints. Users may change vehicles during their trip. This change of vehicle, called a transfer, is made at specific locations called transfer points. Solving the DARPT involves modeling and algorithmic difficulties. In this paper we provide a solution method based on an Adaptive Large Neighborhood Search (ALNS) metaheuristic and explain how to check the feasibility of a request insertion. The method is evaluated on real-life and generated instances. Experiments show that savings due to transfers can be up to 8% on real-life instances. © 2013 Elsevier Ltd.


Frissen I.,CNRS Research Institute of Communication and Cybernetics of Nantes | Mars F.,CNRS Research Institute of Communication and Cybernetics of Nantes
Quarterly Journal of Experimental Psychology | Year: 2014

It has long been held that steering a vehicle is subserved by two distinct visual processes, a compensatory one for maintaining lane position and an anticipatory one for previewing the curvature of the upcoming road. In this study, we investigated the robustness of these two steering control processes by systematically degrading their visual inputs. Performance was measured at the level of vehicle position and at the level of the actions on the steering wheel. The results show that the compensatory process is more robust to visual degradation than the anticipatory process. The results are also consistent with the idea that steering is under the supervision of a combination of compensatory and anticipatory mechanisms, although they suggest that the quality of the sensory information will determine how information is combined. © 2013 © 2013 The Experimental Psychology Society.


Muller P.,CNRS Research Institute of Communication and Cybernetics of Nantes | Mognol P.,CNRS Research Institute of Communication and Cybernetics of Nantes | Hascoet J.-Y.,CNRS Research Institute of Communication and Cybernetics of Nantes
Journal of Materials Processing Technology | Year: 2013

Functionally Graded Materials (FGM) parts are heterogeneous objects with material composition and microstructure that change gradually into the parts. The distinctive feature of FGM structure gives the possibility of selecting the distribution of properties to achieve the desired functions. Today, multi-material parts manufactured with additive manufacturing processes are not functional. To move from these samples to functional and complex parts, it is necessary to have an overall process control. This global approach requires a control of process parameters and an optimal manufacturing strategy. This paper presents a process modeling and a system control to manufacture FGM parts with a direct laser deposition system. This works enable to choose an adapted manufacturing strategy and control process parameters to obtain the required material distribution and the required geometry. © 2012 Elsevier B.V.


Traore D.,CNRS Research Institute of Communication and Cybernetics of Nantes | De Leon J.,University of León | Glumineau A.,CNRS Research Institute of Communication and Cybernetics of Nantes
Automatica | Year: 2012

In this paper, an observer-based controller scheme is designed to robustly drive a sensorless Induction Motor (IM) even for the case of low frequencies with unknown load torque. Combining the field oriented control strategy with the backstepping control method, we introduce additional integral terms to improve the robustness properties of the controller in spite of uncertainties and perturbations. The estimation of the fluxes, the speed, the load torque and moreover the stator resistance is given by an adaptive interconnected observer. The practical stability of the proposed observercontroller scheme is proved. Finally, some experimental test results are given on the framework of a specific sensorless induction motor benchmark. © 2012 Elsevier Ltd. All rights reserved.

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