Дисертації з теми "Signaux Faible"
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Le, Pelleter Tugdual. "Méthode de discrétisation adaptée à une logique événementielle pour l'utra-faible consommation : application à la reconnaissance de signaux physiologiques." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAT043/document.
Our everyday life is highly dependent on mobile embedded systems. In order to make them suitable to differentapplications, they have underwent size reduction and lifetime extension. However, these improvementsare currently limited by the possibilities of the integrated circuits technologies. In order to push back theboundaries, it is necessary to reconsider the whole digital signal processing chain from scratch to sustain thepower consumption reduction in this kind of system. This work develops on the first hand a strategy thatsmartly uses the level-crossing sampling scheme and on the other combines this sampling method with eventlogicto highly reduce the power consumption in mobile embedded systems. A discretisation method adaptedto the recognition of physiological patterns application is described. A first event-logic (asynchronous) prototypeimplemented on FPGA proved the potential benefits that an adapted sampling scheme could offersto reduce activity compared to a uniform sampling scheme. Electrical simulations performed on a secondprototype, also designed in asynchronous logic, with CMOS AMS 0.35 μm technology, validated a high gainin power consumption
Le, Pas de Sécheval Helman. "Traitement des signaux optiques a tres faible niveau de puissance : application a la detection heterodyne traitement de la phase." Paris 6, 1992. http://www.theses.fr/1992PA066542.
Nicodeme, Marc. "Identifiabilité des signaux parcimonieux structurés et solutions algorithmiques associées : application à la reconstruction tomographique à faible nombre de vues." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0096/document.
This thesis studies different minimization problems with sparses based regularization. More precisely, we want to reconstruct a sparses image, which undergone a linear transformation, with minimization problems. In this manuscript, we will be focused on l1 synthesis, analysis and block minimization which are widely used in sparse approximations. These problems offer competitive results which are theorietical understood only recntly. Different studies on the subject emphasized the contribution of a particular vector called dual certificate. The existence of this dual certificate allows simultaneously to guarantee the exact recovey of an image in noiseless case and to estimate the noise robustness in noisy case. In this work, we introduce eth existence of an optimal dual certificate for the l1 synthesis minimization which minimizes the reconstruction error. As those results have a strong geometrical interpretation, we develop an identifiability criterion which ensures the uniqueness of a solution. This criterion generalizes the work on l1 synthesis minimization tothe analysis case, block case and others
Brizon, Ambre. "Compréhension et gestion des signaux faibles dans le domaine de la santé-sécurité." Phd thesis, École Nationale Supérieure des Mines de Paris, 2009. http://tel.archives-ouvertes.fr/tel-00403623.
Pelissier, Michaël. "Développement d'architecture et de fonctions RF avancées pour la réception de signaux Ultra Large Bande dans les applications à basse consommation." Grenoble INPG, 2006. http://www.theses.fr/2006INPG0153.
Except high data rate applications, Ultra Wide Band (UWB) shows potential great interest for low date rate systems, in which, major constraints rely on power consumption. This thesis presents the development of critical blocs for RF receiver front end of an innovative architecture dedicated to the latter applications. First, the general context of UWB, and several pulse signal receivers are reminded. Two critical points are highlighted: the excessive power consumption of the gain stages and the difficulty to achieve precise resolution in time do main while keeping low cost devices. Thus, first work objective consisted in the development of low power LNA based on matched amplification to the signal shape. Then, we proposed a novel UWB receiver architecture based on super-regeneration. Measurements results of the chip fabricated in 0,13 flm CMOS process validate the concept
Murgia, Carlo. "Codage haute qualité des signaux de parole (20 Hz - 15 kHz) à très faible retard et au débit de 64 kbit/s." Grenoble INPG, 1997. http://www.theses.fr/1997INPG0187.
Ferreira, Esteves Paulo Alexandre. "Techniques d'acquisition à haute sensibilité des signaux GNSS." Thesis, Toulouse, ISAE, 2014. http://www.theses.fr/2014ESAE0016/document.
Satellite navigation (GNSS) is a constant in our days. The number of applications that depend on it is already remarkable and is constantly increasing. With new applications, new challenges have also risen: much of the new demand for signals comes from urban areas where GNSS signal processing is highly complex. In this thesis the issue of weak GNSS signal processing is addressed, in particular at the first phase of the receiver processing, known as signal acquisition. The first axe of research pursued deals with the analysis and compensation of the Doppler effect in acquisition. The Doppler shift that is experienced by a user is one of the main design drivers for the acquisitionmodule and solutions are proposed to improve the sensitivity-complexity trade-off typical of the acquisition process. The second axe of research deals with the characterization of differential GNSS detectors. After a first step of coherent integration, transition to post coherent (noncoherent or differential) integration is required for acquiring weak signals. The quantification of the sensitivity of differential detectors was not found in literature and is the objective of this part of the research. Finally, the third axe of research is devoted to multi-constellation Collective Detection (CD). CD is an innovative approach for the simultaneous processing of all signals in view. Severalissues related to CD are addressed, including the improvement of the CD search process and the hybridization with standard acquisition. Finally, the application of this methodology in the context of a multi-constellation receiver is also addressed, by processing simultaneously real GPS and Galileo signals
Rarbi, Fatah-Ellah. "Conception d’un convertisseur analogique numérique pipeline de grande dynamique et de faible consommation pour le codage des signaux de détecteurs à forte granularité." Grenoble INPG, 2010. http://www.theses.fr/2010INPG0128.
The objective of this thesis is the design of a low power and high dynamic pipeline ADC for high granularity detector read-out. In this thesis, we developed a model for further study of different sources of errors and their consequences on the characteristics of a 12-bit pipeline converter. We also completed an ADC prototype in the limit of technology selected by the CALICE collaboration within the ILC project. New pipeline ADC architecture with a multi-bit MDAC first stage structure including a DEM has been designed to go beyong the limits of technology. Finally, in parallel with the design work, an effort has been devoted to developing test programs for the characterization of different prototypes of A/D converters. We explain the results of testing three prototype 12-bit pipeline ADC achieved during these three years of thesis. A comparison is made with respect to other ongoing studies for the electromagnetic calorimeter of ILD
Udupa, Pramod. "Algorithmes parallèles et architectures évolutives de faible complexité pour systèmes optiques OFDM cohérents temps réel." Thesis, Rennes 1, 2014. http://www.theses.fr/2014REN1S039/document.
In this thesis, low-complexity algorithms and architectures for CO-OFDM systems are explored. First, low-complexity algorithms for estimation of timing and carrier frequency offset (CFO) in dispersive channel are studied. A novel low-complexity timing synchro- nization algorithm, which can withstand large amount of dispersive delay, is proposed and compared with previous proposals. Then, the problem of realization of low-complexity parallel architecture is studied. A generalized scalable parallel architecture, which can be used to realize any auto-correlation algorithm, is proposed. It is then extended to handle multiple parallel samples from ADC and provide outputs, which can match the input ADC rate. The scalability of the architecture for higher number of parallel outputs and different kinds of auto-correlation algorithms is explored. An algorithm-architecture approach is then applied to the entire CO-OFDM transceiver chain. At the transmitter side, radix-22 algorithm for IFFT is chosen and parallel Mul- tipath Delay Commutator (MDC) Feed-forward (FF) architecture is designed which con- sumes lesser resources compared to MDC FF architectures of radix-2/4. At the receiver side, efficient algorithm for Integer CFO estimation is adopted and efficiently realized with- out the use of complex multipliers. Reduction in complexity is achieved due to efficient architectures for timing synchronization, FFT and Integer CFO estimation. Fixed-point analysis for the entire transceiver chain is done to find fixed-point sensitive blocks, which affect bit error rate (BER) significantly. The algorithms proposed are validated using opti- cal experiments by the help of arbitrary waveform generator (AWG) at the transmitter and digital storage oscilloscope (DSO) and Matlab at the receiver. BER plots are used to show the validity of the system built. Hardware implementation of the proposed synchronization algorithm is validated using real-time FPGA platform
Grégoire, Marie-Claude. "Reconstruction d'images cardiaques dynamiques synchronisées à l'ECG par maximum de vraisemblance sur les signaux obtenus à faible taux de comptage avec une gamma-caméra." Compiègne, 1989. http://www.theses.fr/1989COMPD190.
To do a global smoothing, a processing technic of dynamic cardiac studies has been suggested, allowing the simultaneous integration of all the spatial and temporal informations. This technic uses a bayesian estimation, therefore introducing an a priori law of Gibbs. A comparative study was done on low-count simulations, using this method and other classical methods. It has shown the advantages of using all the available temporal informations, and has increased the quality of current clinical results
Dahoumane, Mokrane. "Conception, Réalisation et Caractérisation de l'Electronique Intégrée de Lecture et de Codage des Signaux des Détecteurs de Particules Chargées à Pixels Actifs en Technologie CMOS." Phd thesis, Université de Strasbourg, 2009. http://tel.archives-ouvertes.fr/tel-00475421.
Maitre, Julien. "Détection et analyse des signaux faibles. Développement d’un framework d’investigation numérique pour un service caché Lanceurs d’alerte." Thesis, La Rochelle, 2022. http://www.theses.fr/2022LAROS020.
This manuscript provides the basis for a complete chain of document analysis for a whistleblower service, such as GlobalLeaks. We propose a chain of semi-automated analysis of text document and search using websearch queries to in fine present dashboards describing weak signals. We identify and solve methodological and technological barriers inherent to : 1) automated analysis of text document with minimum a priori information,2) enrichment of information using web search 3) data visualization dashboard and 3D interactive environment. These static and dynamic approaches are used in the context of data journalism for processing heterogeneous types of information within documents. This thesis also proposed a feasibility study and prototyping by the implementation of a processing chain in the form of a software. This construction requires a weak signal definition. Our goal is to provide configurable and generic tool. Our solution is based on two approaches : static and dynamic. In the static approach, we propose a solution requiring less intervention from the domain expert. In this context, we propose a new approach of multi-leveltopic modeling. This joint approach combines topic modeling, word embedding and an algorithm. The use of a expert helps to assess the relevance of the results and to identify topics with weak signals. In the dynamic approach, we integrate a solution for monitoring weak signals and we follow up to study their evolution. Wetherefore propose and agent mining solution which combines data mining and multi-agent system where agents representing documents and words are animated by attraction/repulsion forces. The results are presented in a data visualization dashboard and a 3D interactive environment in Unity. First, the static approach is evaluated in a proof-of-concept with synthetic and real text corpus. Second, the complete chain of document analysis (static and dynamic) is implemented in a software and are applied to data from document databases
Delcombel, Nicolas. "Cybersécurité en réalité virtuelle : améliorer le processus de détection d’intrusion, d’investigation et de décision via l’utilisation de techniques de visualisations 3D immersives." Electronic Thesis or Diss., Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2023. http://www.theses.fr/2023IMTA0387.
In this thesis, we examined how virtual reality could contribute to assisting operators in cyber operation centers who are responsible for processing a large number of alerts within tight deadlines. To sort through these alerts, operators compare the behavior of the monitored system with its nominal behavior and must correlate numerous and diverse data. The 2D tools they currently have do not provide effective visualizations. They are limited by their difficulty in correlating data between multiple visualizations, and in representing the evolution of a system’s behavior over time. Therefore, we created a 3D visualization concept that overcomes these limitations. We developed an immersive prototype based on this concept, which we evaluated compared to 2D visualizations. The results show greater efficiency of our prototype in processing complex data, while allowing increased user engagement at the cost of additional physical effort and the inability to interact with traditional 2D tools in the virtual environment. We thus devised a concept for an immersive cybersecurity environment that enables the use of 3D visualizations while having access to conventional cybersecurity tools. We demonstrated that all the necessary software components for its realization are available and have begun combining them to create a limited but functional prototype
MEVEL, Olivier. "Du role des signaux faibles sur la reconfiguration des processus de la chaîne d e valeur de l'organisation : l'exemple d'une centrale d'achats de la grande distribution française." Phd thesis, Université de Bretagne occidentale - Brest, 2004. http://tel.archives-ouvertes.fr/tel-00009025.
Yaacoub, Tina. "Nouvelles approches pour l'estimation du canal ultra-large bande basées sur des techniques d'acquisition compressée appliquées aux signaux à taux d'innovation fini IR-UWB." Thesis, Brest, 2017. http://www.theses.fr/2017BRES0077/document.
Ultra-wideband impulse radio (IR-UWB) is a relatively new communication technology that provides an interesting solution to the problem of RF spectrum scarcity and meets the high data rate and precise localization requirements of an increasing number of applications, such as indoor communications, personal and body sensor networks, IoT, etc. Its unique characteristics are obtained by transmitting pulses of very short duration (less than 1 ns), occupying a bandwidth up to 7.5 GHz, and having an extremely low power spectral density (less than -43 dBm / MHz). The best performances of an IR-UWB system are obtained with Rake coherent receivers, at the expense of increased complexity, mainly due to the estimation of UWB channel, which is characterized by a large number of multipath components. This processing step requires the estimation of a set of spectral components for the received signal, without being able to adopt usual sampling techniques, because of the extremely high Nyquist limit (several GHz).In this thesis, we propose new low-complexity approaches for the UWB channel estimation, relying on the sparse representation of the received signal, the compressed sampling theory, and the reconstruction of the signals with finite rate of innovation. The complexity reduction thus obtained makes it possible to significantly reduce the IR-UWB receiver cost and consumption. First, two existent compressed sampling schemes, single-channel (SoS) and multi-channel (MCMW), are extended to the case of UWB signals having a bandpass spectrum, by taking into account realistic implementation constraints. These schemes allow the acquisition of the spectral coefficients of the received signal at very low sampling frequencies, which are not related anymore to the signal bandwidth, but only to the number of UWB channel multipath components. The efficiency of the proposed approaches is demonstrated through two applications: UWB channel estimation for low complexity coherent Rake receivers, and precise indoor localization for personal assistance and home care.Furthermore, in order to reduce the complexity of the MCMW approach in terms of the number of channels required for UWB channel estimation, we propose a reduced number of channel architecture by increasing the number of transmitted pilot pulses. The same approach is proven to be also useful for reducing the sampling frequency associated to the MCMW scheme.Another important objective of this thesis is the performance optimization for the proposed approaches. Although the acquisition of consecutive spectral coefficients allows a simple implementation of the MCMW scheme, we demonstrate that it not results in the best performance of the reconstruction algorithms. We then propose to rely on the coherence of the measurement matrix to find the optimal set of spectral coefficients maximizing the signal reconstruction performance, as well as a constrained suboptimal set, where the positions of the spectral coefficients are structured so as to facilitate the design of the MCMW scheme. Finally, the approaches proposed in this thesis are experimentally validated using the UWB equipment of Lab-STICC CNRS UMR 6285
Caron-Fasan, Marie-Laurence. "Veille stratégique : création de sens à partir de signaux faibles." Grenoble 2, 1997. http://www.theses.fr/1997GRE21022.
Our research deals with business intelligence and more specifically supports for a better processing of strategic informations known as weak signals. This work is based on two statements: theoretical observations lead us to state that strategic formulation support methods are inadapted to the process of weak signals; which is confirmed in practice by manager's difficulties to treat strategic information. In order to answer to these difficulties, we have created, by analazing area of creativity and cognitive science, a processing weak signals support method, that is to say an environmental sensemaking method. This method has been evaluated in a laboratory study, presented within 19 companies and implement in 1 firm in order to prove its practibility and utility. Furthemore, our findings have lead us to bring new knowledge concerning individual sensemaking activity
Rayne, Alexandre. "Prévenir les ruptures stratégiques : du bon usage des signaux faibles /." Paris : l'Harmattan, 2009. http://catalogue.bnf.fr/ark:/12148/cb41416804j.
Ltaifa, Marwa. "Tests optimaux pour détecter les signaux faibles dans les séries chronologiques." Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0189.
This thesis focuses on the construction of locally asymptotically optimal tests to detect breaks in the mean of Conditional Heteroskedastic AutoRegressive Nonlinear (CHARN) models described by the following stochastic equation: begin{equation} X_t=T(Z_{t-1})+gamma^{top}omega(t)+V(Z_{t-1})varepsilon_t,quad tinzz, end{equation} where «gamma=(gamma_1,ldots,gamma_k,gamma_{k+1})^{top} inrr^{k+1}» and for «t_1,ldots,t_k,» «1< t_10,forall xinrr^p» and «n» the number of observations. The model (2) contains a large class of time series models like AR, MA, ARMA, ARIMA, ARCH etc. Attention is paid to small breaks. Those which are difficult to observe with the naked eye, unlike those considered in the literature. Such a study does not appear to have already been carried out in the context of time series. The test studied is the likelihood ratio test to test ««H_0:gamma=gamma_0text{ against } H^{(n)}_beta:gamma=gamma_0+dfrac{beta}{sqrt{n}}=gamma_{n},quad n>1,»« for «gamma_0inrr^{k+1}» and «betainrr^{k+1}» characterizing respectively the situation where there is no break, and that where there is at least one break to be found. This document is organized as follows: Chapter 1 constitutes the general introduction to the thesis. There, some useful basic concepts and tools are recalled. Chapter 2 reviews the state of the art on the detection of breaks in time series. This chapter is divided into two parts. The first concerns the estimation of breaks and their locations. The second concerns the tests for the existence of break-points. Chapter 3 deals with the case where the functions « T « and « V « are known, and when they are known but depend on unknown parameters. In the latter case, the situation where the parameter « gamma_0 « is known and the one where it is unknown are studied. When it is unknown, it is estimated by the maximum likelihood method. The study of the test is based essentially on the asymptotic local property (LAN) stated for example in cite{droesbeke1996}. Chapter 4 is a generalization of chapter 3. Here, the magnitude of the jump is arbitrary and unknown. Therefore, one has to test ««H_0:gamma=gamma_0text{ against }H^{(n)}=displaystylebigcup_{betainrr^{k+1}}^{}{ H^{(n)}_beta}.»« A Cramer-Von-Mises type test is constructed. The techniques of cite{ngatchou2009} are used to find the asymptotic distribution of the test under the alternative hypothesis. Chapter 5 presents numerical results obtained using software R. The results obtained for simulated data are first presented and commented. This is followed by those for applications with several real datasets. Chapter 6 concludes the thesis and sets out some prospects
Bergogne, Christian. "Transmission en mode paquet à faible rapport signal à bruit /." Paris : École nationale supérieure des télécommunications, 1997. http://catalogue.bnf.fr/ark:/12148/cb36165913n.
Guénégo, Béatrice. "Conversion numérique de signaux biologiques de faibles intensités pour les applications biomédicales." Electronic Thesis or Diss., université Paris-Saclay, 2023. http://www.theses.fr/2023UPAST230.
According to the World Health Organization, cardiac ischemia is the world's leading cause of death. Ischemia is an insufficient vascularization of myocardial cells, which, if prolonged, leads to the necrosis of part of the heart, i.e., a cardiac infarction, endangering the patient's life. However, if ischemia is treated in time, it can have no impact on the patient's health. An embedded system that detects cardiac ischemia over long periods, without requiring medical staff monitoring, and provides alerts would enable patients to be taken care of earlier, increasing their chances of avoiding a heart attack.The electrocardiogram (ECG) is a measurement of the heart's electrical activity, commonly used in medicine to make an initial diagnosis. Examining the signal morphology and the time intervals between different events gives hints of eventual pathologies. The diagnosis of ischemia is based on variations in the part of the ECG named ST segment. Some embedded systems using the ECG to detect cardiac arrhythmias already exist, but none target cardiac ischemia. In this context, the originality of this work is in the design of an integrated system that can detect ST segment variations for ischemia diagnosis. The main difficulties of such a system's design are ST segment preservation during the acquisition stage and the conception of a signal processing method adapted to integrated circuits (power consumption, complexity, ST segment preservation).In this thesis, we studied the design of an integrated system for ECG acquisition and processing for cardiac ischemia detection. The various circuits, simulations, and layouts were realized in 180 nm using XFAB xh018 technology. The standard giving minimum performance for electrocardiograms published by the International Electrotechnical Commission (IEC) was used to quantify ST-segment distortion. We first designed an analog acquisition stage from the system to the transistor level. Simulations of this stage were then carried out to confirm its compliance with the IEC standard and to estimate its power consumption. As the design of an analog-to-digital converter is not new to the state of the art, it was not addressed during this thesis. Then, we conceived an integrated implementation of the discrete wavelet transform, used to eliminate noise and obtain information on the signal's fiducial points while retaining the possibility of reconstructing the signal. We first simulated an implementation of Mallat's algorithm in Python, which was then realized in VHDL, and finally, the place and route step was carried out for several wavelets. Layouts and post-layout simulation results were used to determine which wavelet offered the best trade-off between signal distortion, baseline wander elimination, power consumption, and circuit area.This work covers the design and dimensioning of the essential blocks of an ECG acquisition chain dedicated to ST segment detection that can be integrated. It may be completed by implementing an embedded decision-making method before the physical realization of the chip
Polonovski, Jean-Pierre. "Conversion numérique analogique à faible coût." Paris 11, 1985. http://www.theses.fr/1985PA112378.
Two D/A conversion techniques are discussed. The first one consists on averaging a digital signal of a given duty cycle. The second one uses two equal switched capacitors
Ka, Ahmad Khoureich. "Méthodes à faible complexité algorithmique pour l'analyse d'ECG." Phd thesis, Rennes 1, 2012. https://ecm.univ-rennes1.fr/nuxeo/site/esupversions/96446b82-5669-4387-bb4f-bda6a14bfe0a.
Cette thèse a porté sur l'analyse des électrocardiogrammes en vu de développer de nouvelles méthodes efficaces de classification des arythmies (un outil de diagnostique) et de localisation automatique des battements anormaux en temps réel dans un signal ECG (un outil de surveillance). Les signaux ECG sont prétraités et les battements extraits sont compressés puis analysés à l'aide de la décomposition en ondellettes. La méthode de classification proposée exploite les spécificités du patient en faisant un regroupement contextuel des battements et en utilisant une base de données de battements cardiaques annotés. La méthode utilise également une fonction de similarité pour comparer deux battements donnés. La méthode de localisation exploite aussi la décomposition en ondelettes mais se base sur une partie des données disponibles (set of parsimony) pour détecter automatiquement et temps réel à l'aide d'une fonction masque les battements cardiaques anormaux contenus dans le signal ECG. Les deux méthodes ont été testées sur les signaux électrocardiogrammes du MIT-BIH arrhythmia database et des bons résultats ont été obtenus
Ka, Ahmad Khoureich. "Méthodes à faible complexité algorithmique pour l'analyse d'ECG." Phd thesis, Université Rennes 1, 2012. http://tel.archives-ouvertes.fr/tel-00816445.
Grâce, Erwan. "Hiérarchie mémoire reconfigurable faible consommation pour systèmes enfouis." Phd thesis, Université Rennes 1, 2010. http://tel.archives-ouvertes.fr/tel-00783898.
Graff, Christian. "Signaux électriques et comportement social du poisson à faibles décharges, Marcusenius macrolepidotus (mormyridae, teleostei)." Paris 11, 1986. http://www.theses.fr/1986PA112054.
This thesis deals with Marcusenius rnacrolepidotus (mormyridae), a teleost fish, emitter of weak-electric pulses. Its locomotor and electric social behaviours are described. The histology of the electric emitter- and receptor organs is presented. The movements of groups are first observed in various environments, and then quantified in experimental conditions. A novel set-up simultaneously records the electric pulses from the group and from one (individual) fish within the group. A computer analyses the rythm of interpulse intervals. The electric activity of each fish shows individual stereotypies. It changes according to locomotor activity. Fish of this species show a tendancy to aggregate depending on the situation. The group's electric activity differs from a random mix of individual electric activities because of two types of interactions, namely stopping responses (to one fish, from the rest of the group), and echo responses (between two fish in the group). These results show a social system built on communication signals to which humans are insensible
Graff, Christian. "Signaux électriques et comportement social du poisson à faibles décharges, Marcusenius macrolepidotus, Mormyridae, teleostei." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37598011n.
Morel, Martine. "Exploration des signaux faibles de la perte de confiance pendant une collaboration à distance." Compiègne, 2011. http://www.theses.fr/2011COMP1934.
The remote collaboration growth induces a need of new tools to compensate the perceptive instantiations of trust during a physical presence interaction. In this research about the weak signals of loss in trust, we have been interested in the perception of the loss in trust from the origin in their emotional biophysics birth until their expression in talk. Then, we have crossed the data of emotional expression of loss in trust that we had collect with an interview and with the collective production of the remote collaboration in a case of an offshore web development (European clients, Pantha Corp. Project manager in Australia) in outsourcing (Chinese a distributed software development team) using the AGILE/SCRUM method where the interactions stand everyday and only through computers. This research contributes to others referring to the link between a team emotional life and its performance. In addition Université de Technologie de Compiègne Martine MOREL Thèse en gestion 2011 Page 10 sur 442 to that, this research propose an adaptation of managerial practices of control by production scorecard, and also, of evaluation of quality, by rooting them in the analyze of interactions including their emotional component to infer on the mutual ability of stakeholders to maintain a trust relationship, this new concept is called "Quality 2. 0. " Moreover, in this Quality 2. 0 concept, the sensitive human being is placed in the center of the interaction at work. However, this research has been limited about the biophysics explorations of emotions in a situation in a remote interaction but it contributes to open more perspectives about the links
Graces, Erwan. "Hiérarchie mémoire reconfigurable faible consommation pour systèmes enfouis." Phd thesis, Université Rennes 1, 2010. http://tel.archives-ouvertes.fr/tel-00554158.
Enguehard, Cédric. "Analyse et Mesure des Structures Différentielles RF Faible Bruit." Limoges, 2011. http://www.theses.fr/2011LIMO4008.
The constant improvement of the radio-frequency receivers require industrial and research laboratories to improve the limits of noise sensitivity. After many years where noiseless technology brings the most important improvements, differentials architectures open new prospective. Already widespread in the low-frequencies, differentials architectures are increasingly used in RF and millimetre frequencies applications. This thesis study differentials circuits and provide new tracks for the definitions of noise parameters and measurement methodology. The analytical studies are performed using mixed mode, noise waves, chaining theory of RF components. The results are validated by simulations and measurements
Mornet, Clemence. "Reconstruction couleur sous faible éclairement pour des capteurs d'images en technologie CMOS." Thesis, Grenoble, 2011. http://www.theses.fr/2011GRENT112/document.
Thevenin, Mathieu. "Conception et validation d'un processeur programmable de traitement du signal à faible consommation et à faible empreinte silicium : application à la vidéo HD sur téléphone mobile." Phd thesis, Université de Bourgogne, 2009. http://tel.archives-ouvertes.fr/tel-00504704.
Dervin, Mathieu. "Synchronisation de porteuse à très faible rapport signal à bruit pour applications satellite large bande." Phd thesis, Télécom ParisTech, 2005. http://pastel.archives-ouvertes.fr/pastel-00001545.
Dervin, Mathieu. "Synchronisation de porteuse à très faible rapport signal à bruit pour applications satellite large-bande /." Paris : École nationale supérieure des télécommunications, 2006. http://catalogue.bnf.fr/ark:/12148/cb40117817g.
Jhaidri, Mohamed Amine. "Techniques de synchronisation à très faible SNR pour des applications satellites." Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2017. http://www.theses.fr/2017IMTA0038/document.
In deep space communication systems, the long distance between the spacecraft and the ground station along with the limited capacity of the on-board power generator result a very low signal to noise ratio (SNR). However, such transmission still possible by using near Shannon limit error correction codes (Turbo code and LDPC code). Nevertheless, to take advantage of this coding gain, the coherent demodulation is mandatory, and the carrier phase synchronization must be reliable at more restrictive SNR. At very low SNR, current synchronization systems are limited and unable to provide the required performances. Our goal is to improve the reliability of the receiver synchronization stage under very difficult conditions of a very low SNR, a variable Doppler effect (Doppler rate) and a blind transmission. This thesis deals with the problem of carrier phase synchronization for the downlink of a Deep Space transmission. After the study of the existing solutions, we selected the phase locked loop (Phase Locked Loop: PLL). In an industrial context, PLL offers the best trade-off between complexity and performance. Several phase detectors based on the maximum likelihood criterion were considered and characterized by their S-curves. Based on the equivalent models, we have developed a new study of the non-linear acquisition phase of a second-order PLL with a semi-sinusoidal phase error detector. The second part of the thesis was dedicated to the antennas combining techniques. These methods aim to improve the link budget of the transmission and offer more flexibility. At the end of this part, we proposed a new antennas combining scheme that improves the operating threshold of existing systems
Alaeddinei, Hamzé. "Application de la transformée en nombres entiers à la conception d'algorithmes de faible complexité pour l'annulation d'échos acoustiques." Brest, 2007. http://www.theses.fr/2007BRES2019.
The principal objective of our study is to evaluate the possibility of an acoustic caneeler system development in real time. To reduce the computational cost of this system, we looked further into the mathematical bases of the Number Theoretic Transform (NTT) which is meant to find more and more various applications in signal processing. We introduced more particularly the Fermat Number Transform (FNT), which, compared to the Fast Fourier Transform (FFT), allows reduction of several multiplications which are necessary to achieve certain functions such as convolution products. To highlight this transformation, we proposed and studied 110W algorithms for echo cancelers of low complexity, which we treated by blocks and made robust before implanting them using the FNT. The result of this implementation, compared to an implementation by the FFT, has shown a strong reduction in the number of multiplications along with an increase in the number of classical operations. To reduce this rise, we proposed a new technique of the transform, entitled Generalized Sliding FNT (GSFNT), which consists in calculating the FNT of a succession of sequences that differ from a certain number of samples from 011e to another. The numerical simulations show that a GSFNT-based echo canceler helps to remedy the increase in the number of classical operations observed by FNT-based echo canceler. Finally, the implementation of algorithms for echo canceler and through a new procedure of Multi-Delay Filter (MDF) algorithm associated with the new method for the step-size adaptation coefficient, has permitted a significant reduction in the computational complexity
Paris, Silvia. "Méthodes de détection parcimonieuses pour signaux faibles dans du bruit : application à des données hyperspectrales de type astrophysique." Phd thesis, Université Nice Sophia Antipolis, 2013. http://tel.archives-ouvertes.fr/tel-00933827.
Vaiter, Samuel. "Régularisations de Faible Complexité pour les Problèmes Inverses." Phd thesis, Université Paris Dauphine - Paris IX, 2014. http://tel.archives-ouvertes.fr/tel-01026398.
Virot, Léopold. "Développement de photodiodes à avalanche en Ge sur Si pour la détection faible signal et grande vitesse." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112414/document.
To address the issue related to the limitations of metallic interconnects especially in terms of bitrate, Si photonics has become the technology of choice. One of the basic components of photonic circuits is the photodetector: It allows to convert an optical signal into an electrical signal. Photodetectors based on Ge on Si have shown their potential and offer the best alternative to III-V photodetectors, for integration into Si photonic circuits. In this context, the Ge on Si photodiodes have been studied. The optimization of pin photodiodes enabled the achievement of state of the art results. A new approach using a double lateral Si/Ge/Si heterojunction was proposed to increase the responsivity but also to provide a better integration solution, especially with Si modulators. To further increase the sensitivity of the receivers, the use of avalanche photodiodes, is however necessary. SACM (Separate Absorption Charge Multiplication) structure, combining Si low multiplication noise and Ge absorption at telecom wavelengths was first studied. Models have been developed to optimize the devices, and the photodiodes have been fabricated and characterized. The results obtained on the surface illuminated photodiodes (Gain-bandwidth product of 560GHz only -11V) are very encouraging for waveguide integration. On the other hand, Ge on Si pin photodiodes have been studied in avalanche. The small width of the intrinsic region contributed to the multiplication noise reduction thanks to "dead space" effect, and operation at 10Gbps for a gain of 20 and an optical power of -26dBm at only-7V, without using amplifier (TIA), have been demonstrated. These developments open the way to fast, low power consumption and high sensitivity receivers
Smith, Isabelle. "Détection d'une source faible : modèles et méthodes statistiques : application à la détection d'exoplanètes par imagerie directe." Phd thesis, Université de Nice Sophia-Antipolis, 2010. http://tel.archives-ouvertes.fr/tel-00548905.
Camus, Manuel. "Architecture de réception RF très faible coût et très faible puissance : application aux réseaux de capteurs et au standard ZigBee." Phd thesis, Université Paul Sabatier - Toulouse III, 2008. http://tel.archives-ouvertes.fr/tel-00309926.
Schwoerer, Jean. "Études et implémentation d'une couche physique UWB impulsionnelle à bas débit et faible complexité¶." Phd thesis, INSA de Rennes, 2006. http://tel.archives-ouvertes.fr/tel-00638640.
Vayssade, Thibault. "Une approche digitale pour le test faible coût de circuits intégrés RF : application à un transceiver ZigBee." Thesis, Montpellier, 2020. http://www.theses.fr/2020MONTS065.
This thesis focuses on the reduction of testing costs for RF integrated circuits. The original approach that is investigated relies on the use of a standard digital ATE to perform an under-sampled acquisition of the RF signal to be analyzed. The basic idea is to use the comparator present in a digital tester channel to convert the RF signal into a binary sequence. During this conversion, the information carried by the RF signal (amplitude, frequency, phase ...) is transformed into a timing information contained in the binary vector captured by the ATE. The objective is then to develop dedicated processing algorithms able to retrieve the essential RF signal characteristics from the analysis of the binary vector. The major benefit of this solution is that it eliminates the need of expensive RF test resources traditionally required. In addition, since digital channels are generally available in large numbers on a standard ATE, this approach also provides the ability to implement multi-site tests to further reduce testing costs. In this thesis, the proposed approach is implemented for ZigBee Transceiver from NXP Semiconductors operating at 2.4 GHz and intended for the growing market of Internet of Things (IoT). The under-sampling conditions allowing to preserve the information contained in the RF signal while respecting the test equipment constraints are defined and dedicated algorithms are developed to implement the various tests specified by IEEE Std 802.15.4 ™ (power test, spectral mask test, EVM measurements). The proposed solution is first evaluated in simulation within the Matlab environment. A laboratory test bench is then developed to carry out an initial validation. Finally, measurements performed with an ATE on several hundreds of circuits in an industrial environment fully validate the proposed solution
Andrianarison, Maherizo. "New Methods and Architectures for High Sensitivity Hybrid GNSS Receivers in Challenging Environments." Thesis, Toulouse, ISAE, 2018. http://www.theses.fr/2018ESAE0016/document.
GNSS satellite navigation systems are constantly evolving and have been already used in many applications. With the advent of the new systems Galileo and BeiDou as well as the modernization of GPS and GLONASS systems, new satellites and numerous new frequencies and signals will appear in the coming years and will open door to countless new applications that are currently impossible. The rapid evolution of mobile telephony and personal navigation devices (PND) requires better use of navigation systems in non-ideal environments, especially the need for positioning in deep urban area. On the one hand, users are waiting for a high positioning accuracy, because of the proximity to various points of interest. On the other hand, urban environment brings specific difficulties in receiving GNSS signals.GNSS navigation signals cannot be properly captured in urban and "indoor" environments. Signal levels are very low and it is almost impossible to acquire and track signals autonomously because of the strong attenuation of signals due to obstacles. In addition, indoor and urban positioning are also subject to multipath problems, masking, interference and jamming. Under these conditions, we must be able to process highly degraded or very short signals that do not allow the receiver to go through the tracking process. Thus, this leads us to the need to rethink the architecture of GNSS receiver for modern applications.This thesis project consists of developing new GNSS methods and architectures of high sensitivity and robustness to signal degradations and designing new algorithms integrated into a hybrid GNSS receiver capable of operating in deep urban environments.The methodology involves the use of the new concept of “Collective Detection (CD)”, also called “collaborative acquisition”. The collaborative approach that treats multi-satellite signals all together opens an interesting solution. Many techniques exist in the literature to solve the problems of positioning in urban environments, but we propose the new Collective Detection approach because of its performance as both a Direct Positioning method, providing a coarse position/clock-bias solution directly from acquisition, and High-Sensitivity acquisition method, by application of vector detection of all satellites in view. Indeed, the correct combination of the correlation values of several satellites can reduce the required Carrier-to-Noise Ratio (C/N_0) level of the satellite signals which cannot be acquired individually by standard signal processing (acquisition and tracking) but make it possible to use them constructively to a positioning solution. The combination of different GNSS signals can considerably increase the acquisition sensitivity of the receiver. Despite the advantages of this approach, it also has drawbacks such as the high computational burden because of the large number of candidate points in the position/clock-bias domain. Thus, the work proposed in this thesis consists of reducing the complexity of the CD by optimizing the search for candidate points in position/clock-bias domain. Finally, the goal is to apply the CD approach to Cooperative GNSS Positioning for modern navigation in harsh environments. For that, algorithms for optimally exploiting receiver resources by selecting the best satellites or the reference station will be developed according to certain criteria such as the C/N_0 level, the elevation angle, and the geometric configuration of the visible satellites. The ultimate goal is to propose a design of a new smart receiver “High Sensitivity Cognitive GNSS Receiver (HS-CGR)” to optimally receive and process GNSS signals
Heubi, Alexander. "De l'algorithme de traitement numérique du signal à sa réalisation à faible consommation par un circuit intégré spécifique /." [S.l.] : [s.n.], 1997. http://library.epfl.ch/theses/?nr=1743.
Cailly, Alexis. "Traitement du signal multidimensionnel pour les images hyperspectrales en présence d'objets de faibles dimensions spatiales." Ecole centrale de Marseille, 2012. http://www.theses.fr/2012ECDM0008.
Florès, Laurent. "Branddelphi : une nouvelle méthode de génération d'idées pour la mise à jour des "signaux faibles" dans le développement des nouveaux produits." Grenoble 2, 2005. http://www.theses.fr/2005GRE21031.
Having illustrated the importance of idea generation in the new product development process and certain weaknesses of existing methods to detect "weak signals" ideas to drive successful product innovation, the author offers the development of a new ideation method : Branddelphi. Inspired from certains principles of brainstorming (Osborn, 1953), information theory (Shannon, 1948), Delphi method (Dalkey, 1969), evolutionary and adaptive algorithms (Seck, 1996, Goldberg, 2000). The method is developed, tested and validadted in terms of reliability, internal and external validities in two product categories (involving, not involving) and show superior performance in comparison to brainstorming and Delphi method. Future research directions are highlighted with specific interest in idea stating rather than content only, the control and sequential involvement of different consumers (Roger, 1983), as well as different alternatives for algorithm optimization and consumers optimal creative simulation (Zaltman, 2003)
Andriambeloson, Eric. "La contribution des réseaux à signaux faibles à l'innovation technologique dans les PME manufacturières du secteur des équipements de transports terrestres /." Thèse, Trois-Rivières, Université du Québec à Trois-Rivières, 2000. http://www.uqtr.ca/biblio/notice/resume/03-2222717R.html.
Andriambeloson, Eric. "La contribution des réseaux à signaux faibles à l'innovation technologique dans les PME manufacturières du secteur des équipements de transports terrestres." Thèse, Université du Québec à Trois-Rivières, 2000. http://depot-e.uqtr.ca/3042/1/000676308.pdf.
González, Santos Ángel de Dios. "Circuits de traitement de signal numérique en temps continu ultra-faible consommation en technologie 28nm FDSOI pour applications audio." Thesis, Lille 1, 2020. http://www.theses.fr/2020LIL1I047.
The focus of this work is the study and development of a feature extraction system using Continuous-Time Digital Signal Processing (CT DSP) techniques, to mitigate the drawbacks of existing implementations based on traditional analog and digital solutions of always-on monitoring sensors for the Internet of Things (IoT). The target is to extract the spectral content of an audio signal using a novel architecture based on a cascade of configurable CT DSP Finite Impulse Response (FIR) filters. An efficient cascade scheme is enabled by the proposed glitch elimination and delta encoding techniques. Additionally, this work introduces a CT function to estimate the instantaneous power within selected frequency bands to build an output spectrogram. The proposed 12-band system has been validated using behavioral simulations. The key element for the implementation of this system is the digital delay element. A new delay element has been designed and fabricated in 28nm FDSOI technology and achieves a record tuning range from 30 ns to 97 µs with a power consumption of 15 fJ/event. By extrapolating this result, the system would have an overall peak power consumption of 2.85 µW when processing typical female speech, while consuming approximately 100 nW when no events are generated. Thus, the average system power consumption outperforms state-of-the-art feature extraction circuits
Breloy, Arnaud. "Algorithmes d’estimation et de détection en contexte hétérogène rang faible." Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLN021/document.
One purpose of array processing is the detection and location of a target in a noisy environment. In most cases (as RADAR or active SONAR), statistical properties of the noise, especially its covariance matrix, have to be estimated using i.i.d. samples. Within this context, several hypotheses are usually made: Gaussian distribution, training data containing only noise, perfect hardware. Nevertheless, it is well known that a Gaussian distribution doesn’t provide a good empirical fit to RADAR clutter data. That’s why noise is now modeled by elliptical process, mainly Spherically Invariant Random Vectors (SIRV). In this new context, the use of the SCM (Sample Covariance Matrix), a classical estimate of the covariance matrix, leads to a loss of performances of detectors/estimators. More efficient estimators have been developed, such as the Fixed Point Estimator and M-estimators.If the noise is modeled as a low-rank clutter plus white Gaussian noise, the total covariance matrix is structured as low rank plus identity. This information can be used in the estimation process to reduce the number of samples required to reach acceptable performance. Moreover, it is possible to estimate the basis vectors of the clutter-plus-noise orthogonal subspace rather than the total covariance matrix of the clutter, which requires less data and is more robust to outliers. The orthogonal projection to the clutter plus noise subspace is usually calculated from an estimatd of the covariance matrix. Nevertheless, the state of art does not provide estimators that are both robust to various distributions and low rank structured.In this Thesis, we therefore develop new estimators that are fitting the considered context, to fill this gap. The contributions are following three axes :- We present a precise statistical model : low rank heterogeneous sources embedded in a white Gaussian noise.We express the maximum likelihood estimator for this context.Since this estimator has no closed form, we develop several algorithms to reach it effitiently.- For the considered context, we develop direct clutter subspace estimators that are not requiring an intermediate Covariance Matrix estimate.- We study the performances of the proposed methods on a Space Time Adaptive Processing for airborne radar application. Tests are performed on both synthetic and real data