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Saint-Étienne-de-Baïgorry, France

Destercke S.,CIRAD - Agricultural Research for Development | Strauss O.,Laboratoire dInformatique
Soft Computing | Year: 2012

Selecting a particular kernel to filter a given digital signal can be a difficult task. One solution to solve this difficulty is to filter with multiple kernels. However, this solution can be computationally costly. Using the fact that most kernels used for low-pass signal filtering can be assimilated to probability distributions (or linear combinations of probability distributions), we propose to model sets of kernels by convex sets of probabilities. In particular, we use specific representations that allow us to perform a robustness analysis without added computational costs. The result of this analysis is an interval-valued filtered signal. Among such representations are possibility distributions, from which have been defined maxitive kernels. However, one drawback of maxitive kernels is their limited expressiveness. In this paper, we extend this approach by considering another representation of convex sets of probabilities, namely clouds, from which we define cloudy kernels. We show that cloudy kernels are able to represent sets of kernels whose bandwidth is upper and lower bounded, and can therefore be used as a good trade-off between the classical and the maxitive approach, avoiding some of their respective shortcomings without making computations prohibitive. Finally, the benefits of using cloudy filters is demonstrated through some experiments. © 2011 Springer-Verlag.

Mauris G.,Laboratoire dInformatique
IEEE Transactions on Instrumentation and Measurement | Year: 2010

At the application level, it is important to be able to define the measurement result as an interval that will contain an important part of the distribution of the measured values, that is, a coverage interval. This practice acknowledged by the International Organization for Standardization (ISO) Guide is a major shift from the probabilistic representation. It can be viewed as a probability/possibility transformation by viewing possibility distributions as encoding coverage intervals. In this paper, we extend previous works on unimodal distributions by proposing a possibility representation of bimodal probability distributions. Indeed, U-shaped distributions or Gaussian mixture distribution are not very rare in the context of physical measurements. Some elements to further propagate such bimodal possibility distributions are also exposed. The proposed method is applied to the case of three independent or positively correlated C-grade resistors in series and compared with the Guide to the Expression of Uncertainty in Measurement (GUM) and Monte Carlo methods. © 2009 IEEE.

Hassoune I.,Laboratoire dInformatique | Flandre D.,Catholic University of Louvain | O'Connor I.,Ecole Centrale Lyon | Legat J.-D.,Catholic University of Louvain
IEEE Transactions on Circuits and Systems I: Regular Papers | Year: 2010

In this paper, we first propose a new structure of a hybrid full adder, namely, the branch-based logic and pass-transistor (BBL-PT) cell, which we implemented by combining branch-based logic and pass-transistor logic. Evolution of the proposed cell from its original version to an ultralow-power (ULP) cell is described. Quantitative comparisons of the optimized version, namely, the ULP full adder (ULPFA), are carried out versus the BBL-PT full adder and its counterparts in two well-known and commonly used logic styles, i.e., conventional static CMOS logic and complementary pass logic (CPL), in a 0.13- μm PD SOI CMOS with a supply voltage of 1.2 V, demonstrating power delay product (PDP) and static power performance that are more than four times better than CPL design. This could lead to tremendous benefit for multiplier application. The implementation of an 8-bit ripple carry adder based on the ULPFA is finally described, and comparisons between adders based on full adders from the prior art and our ULPFA version demonstrate that our development outperforms the static CMOS and the CPL full adders, particularly in terms of power consumption and PDP by at least a factor of two. © 2006 IEEE.

Silkan H.,Laboratoire dInformatique | Hanyf Y.,Chouaib Doukkali University
Information (Switzerland) | Year: 2015

In this paper, we propose a new method for 2D/3D object indexing and retrieval. The principle consists of an automatic selection of optimal views by using an incremental algorithm based on pivot selection techniques for proximity searching in metric spaces. The selected views are afterward described by four well-established descriptors from the MPEG-7 standard, namely: the color structure descriptor (CSD), the scalable color descriptor (SCD), the edge histogram descriptor (EHD) and the color layout descriptor (CLD). We present our results on two databases: The Amsterdam Library of Images (ALOI-1000), consisting of 72,000 color images of views, and the Columbia Object Image Library (COIL-100), consisting of 7200 color images of views. The results prove the performance of the developed method and its superiority over the k-means algorithm and the automatic selection of optimal views proposed by Mokhtarian et al. © 2015 by the authors.

Allard J.,French Institute for Research in Computer Science and Automation | Allard J.,Laboratoire dInformatique | Lesage J.-D.,French Institute for Research in Computer Science and Automation | Lesage J.-D.,Laboratoire Dinformatique Of Grenoble Lig | And 2 more authors.
Presence: Teleoperators and Virtual Environments | Year: 2010

This paper focuses on the design of high performance VR applications. These applications usually involve various I/O devices and complex simulations. A parallel architecture or grid infrastructure is required to provide the necessary I/O and processing capabilities. Developing such applications faces several difficulties, two important ones being software engineering and performance issues. We argue that application modularity is a key concept to help the developer handle the complexity of these applications. We discuss how various approaches borrowed from other existing works can be combined to significantly improve the modularity of VR applications. This led to the development of the FlowVR middleware that associates a data-flow model with a hierarchical component model. Different case studies are presented to discuss the benefits of the approach proposed. © 2010 by the Massachusetts Institute of Technology.

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