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showing 10 items of 404 documents
Conception d'un outil de prototypage rapide sur le FPGA pour des applications de traitement d'images
2011
This manuscript presents work to propose a development cycle to establish RISP processors in a reprogrammable chip (FPGA). After a description of the various possible solutions to produce image processing prototypes, this document describes a method which consists in generating hardware models of processor target to image processing, with operators just for a given application. Test with a set of common algorithm makes evaluate the performances of the design cycle proposed. Rapid prototyping of a contact less biometric system, based on palmprint recognition, is also realized on the test platform.
Semantic-aware news feeds management framework
2010
In the Web, RSS and Atom (feeds) are probably the most popular and highly utilized XML formats which allow web communities, publishing industries, web services, etc. to publish and exchange XML documents. In addition, they allow a user to consume data/information easily without roaming from site to site using software applications. Here, the user registers her favorite feed providers; and each provider sends the list of news items changed since the last download. However, registering a number of feed sources in feed aggregators cause both heterogeneity and information overloading problems. Besides, none of the existing RSS/feed aggregators provide an approach that integrates (merges) feeds …
Nouvelles méthodes de traitement de signaux multidimensionnels par décomposition suivant le théorème de Superposition de Kolmogorov
2010
The processing of multidimensional signal remains difficult when using monodimensional-based methods. Therefore, it is either required to extend monodimensional methods to several dimensions, which is not always possible, or to convert the multidimensional signals into 1D signals. In this case, the priority is to preserve most of the properties of the original signal. In this context, the Kolmogorov Superposition Theorem offers a promising theoretical framework for multidimensional signal conversion. In 1957, Kolmogorov demonstrated that any multivariate function can be written as sums and compositions of monovariate functions.We have focused on the image decomposition according to the supe…
Nouvelle génération de systèmes de vision temps réel à grande dynamique
2013
This thesis is a part of the EUREKA European project called "High Dynamic Range - Low NoiseCMOS imagers", which developped new approaches to design high performance CMOS sensors.The purpose of this thesis is to design a real-time high dynamic range (HDR) vision system. Themain focus will be the real-time video reconstruction at 60 frames/sec in an embedded architecture.Most of the sensors produce a digital image that is not able to reproduce the real world light inten-sities. Similarly, monitors, printers and current displays do not recover of a wide tonal range. Theapproach proposed in this thesis is multiple acquisitions, taken with different exposure times, to over-come the limitations o…
Réduction de dimensionalité et saillance pour la visualisation d'images spectrales
2012
Nowadays, digital imaging is mostly based on the paradigm that a combinations of a small number of so-called primary colors is sufficient to represent any visible color. For instance, most cameras usepixels with three dimensions: Red, Green and Blue (RGB). Such low dimensional technology suffers from several limitations such as a sensitivity to metamerism and a bounded range of wavelengths. Spectral imaging technologies offer the possibility to overcome these downsides by dealing more finely withe the electromagnetic spectrum. Mutli-, hyper- or ultra-spectral images contain a large number of channels, depicting specific ranges of wavelength, thus allowing to better recover either the radian…
Multi-rogue solutions to the focusing NLS equation
2010
The study of rogue waves is a booming topic mainly in oceanography but also in other fields. In this thesis I construct via Darboux transform a multi-parametric family of smooth quasi-rational solutions of the nonlinear Schödinger equation that present a behavior of rogue waves. For a general choice of parameters the second-order solutions give a model of "three sisters" (three higher than expected waves in a row) while for a particular choice of parameters we obtain the solutions given by Akhmediev et al. in a serie of articles in 2009. Then these solutions allow me to construct rational solutions of the KP-I equation that describe waves in shallow water.
Le cône diamant
2010
The diamond cone was introduced by N. J. Wildberger for the Lie algebra sl(n;R). It is a combinatoric presentation for the space C[N] of polynomials functions on the nilpotent factor N in the Iwasawa decomposition of SL(n;R). This presentation describes the natural layering of this indecomposable N-module. This basis can be indexeded by using some semi standard Young tableaux. We realize the algebra C[N] as a quotient of the shape algebra S_ for SL(n;R). Let us call reduced shape algebra this quotient. It is possible to select a family of semi standard Young tableaux, the quasi standard tableaux, in such a manner to get a basis for the reduced shape algebra. In the present thesis, this cons…
Fibres optiques microstructurées chalcogénures fortement non linéaires à base AS2S3 : vers de nouvelles sources supercontinuum infrarouges
2010
No abstract
Laser control of quantum systems by ultrafast parallel adiabatic passage : application to high fidelity population transfer, state selectivity, and s…
2011
In this work we establish and test the technique of parallel adiabatic passage (PLAP) thatoptimizes the adiabatic passage in the sense that it selects specific paths that allow a fastadiabatic dynamics while preserving the standard robustness of adiabatic techniques. Theintuition of PLAP is based on the fact that the use of eigenvalues that are parallel for alltimes is expected to lead to a small nonadiabatic transition probability from Landau-Zeneranalysis for two-state approximations. In this work we test the robustness of this techniqueand show its superiority to the traditional linearly chirped dynamics with Gaussian pulses. Weshow its extension for two-photon and three-photon transitio…
Trapping and manipulation of colloidal objects using silicon photonic structures integrated into optofluidic chips
2016
Near-field optical forces arise from evanescent electromagnetic fields, such as in the near-field of photonic waveguides and nanocavities where light is highly confined. These contactless forces can be advantageously used to trap and manipulate micro- and nano-objects in solution. This thesis aims at studying these intriguing interactions and investigating their potential applications. The first chapter is an introduction to the fields of colloidal systems and optical trapping, more especially using near-field optical forces. The second chapter presents the experimental setup and the process used to fabricate optofluidic chips with microfluidic channels. The trapping potential experienced b…