Дисертації з теми "Estimation de la norme minimale"
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Bertin, Karine. "Estimation asymptotiquement exacte en norme sup de fonctions multidimensionnelles." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2004. http://tel.archives-ouvertes.fr/tel-00008028.
Повний текст джерелаNembé, Jocelyn. "Estimation de la fonction d'intensité d'un processus ponctuel par complexité minimale." Phd thesis, Université Joseph Fourier (Grenoble), 1996. http://tel.archives-ouvertes.fr/tel-00346118.
Повний текст джерелаNembé, Jocelyn Grègoire Gérard. "Estimation de la fonction d'intensité d'un processus ponctuel par complexité minimale." S.l. : Université Grenoble 1, 2008. http://tel.archives-ouvertes.fr/tel-00346118.
Повний текст джерелаColares, Ricardo Fialho. "Aprimorando metodo para detecção de frequencias baseado na norma-minima." [s.n.], 1997. http://repositorio.unicamp.br/jspui/handle/REPOSIP/261954.
Повний текст джерелаDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
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Resumo: : Este trabalho aborda a aplicação da predição linear na análise de sinais discretos. Examinaremos a sua utilização no problema de estimação de freqüências de um sinal sujeito à ruído. O critério baseado nos mínimos-quadrados será utilizado para a obtenção do preditor ótimo nas formas forward, backward e forward-backward. A ferramenta de decomposição em valores singulares (DVS) será utilizada para a obtenção da solução de norma-mínima para esses preditores. Tal solução particular será detalhadamente estudada para investigar o comportamento dos zeros do polinômio associado ao filtro de erro de predição. A análise desenvolvida trouxe contribuições ao conhecimento dos métodos baseados na norma-mínima, as quais propiciaram a elaboração de uma proposta de um novo método para detecção de freqüências baseado no método FBLP Modificado. Os resultados de simulações obtidos para o método proposto mostram uma SNR de limiar inferior àquela obtida para o método FBLP Modificado. Os resultados também indicam que o novo método é capaz de estimar freqüências em SNR's inferiores àquelas obtidas mesmo para o método da Máxima Verossimilhança
Abstract: This work is concerned with the application of the linear prediction on the discrete signals analysis, aiming the frequency estimation at low signal to noise ratios. The linear prediction is optimized using least squares criterion and each of the following forms: forward, backward, forward-backward. For each one of this cases, a minimum norm solution is obtained through singular value decomposition and a polynomial is formed using the optimized coefficients. The study of the behavior of their zeroes led to new insight into the minimum norm based frequency detection methods, allowing the proposal of a new method, based on the Modified FBLP. The simulation results have shown that this new method is able to detect frequencies at lower signal to noise ratios, even when compared with the Maximum Likelihood method
Mestrado
Mestre em Engenharia Elétrica
Berro, Soumaya. "Identification of muscle activation schemes by inverse methods applied on HD-sEMG signals." Electronic Thesis or Diss., Compiègne, 2022. http://www.theses.fr/2022COMP2708.
Повний текст джерелаFast or real-time identification of the spatiotemporal activation of Motor Units (MUs), functional units of the neuromuscular system, is fundamental in applications as prosthetic control and rehabilitation guidance but often dictates expensive computational times. Therefore, the thesis work was devoted to providing an algorithm that enables the real-time identification of MU spatial and temporal activation strategies by applying inverse methods on HD-sEMG (high-density surface electromyogram) signals from a grid placed over the Biceps Brachii (BB). For this purpose, we propose an innovative approach, that involves the use of the classical minimum norm inverse method and a 3D fitting curve interpolation, namely CFB-MNE approach. This method, based on inverse identification (minimum norm estimation) coupled to simulated motor unit action potential (MUAP) dictionary from a recent model and tested on simulations, allowed the real time localization of simulated individual motor units. A robustness analysis (anatomical, physiological, and instrumental modifications) was then performed to verify the efficiency of the proposed algorithm. Finally, the proposed algorithm was tested on MUs with realistic recruitment patterns giving promising results in both spatial and temporal identification. To conclude, a door to future perspectives was opened, according to the obtained promising results, suggesting the use of machine learning and artificial intelligence (AI) to further boost the performance of the proposed algorithm
Aubry, Christophe. "Estimation parametrique par la methode de la distance minimale pour les processus de poisson et de diffusion." Le Mans, 1997. http://www.theses.fr/1997LEMA1005.
Повний текст джерелаChevret, Sylvie. "Estimation bayesienne en pharmacologie clinique de la dose maximale toleree ou minimale efficace, pour un critere de jugement binaire." Paris 7, 1993. http://www.theses.fr/1993PA077137.
Повний текст джерелаFeki, Oussama. "Contribution à l'implantation optimisée de l'estimateur de mouvement de la norme H.264 sur plates-formes multi composants par extension de la méthode AAA." Thesis, Paris Est, 2015. http://www.theses.fr/2015PEST1009/document.
Повний текст джерелаMixed architectures containing programmable devices and reconfigurable ones can provide calculation performance necessary to meet constraints of real-time applications. But the implementation and optimization of these applications on this kind of architectures is a complex task that takes a lot of time. In this context, we propose a rapid prototyping tool for this type of architectures. This tool is based on our extension of the Adequacy Algorithm Architecture methodology (AAA). It allows to automatically perform optimized partitioning and scheduling of the application operations on the target architecture components and generation of correspondent codes. We used this tool for the implementation of the motion estimator of the H.264/AVC on an architecture composed of a Nios II processor and Altera Stratix III FPGA. So we were able to verify the correct running of our tool and validate our automatic generator of mixed code
Cibaud, David. "Etude d'implémentation d'un récepteur reconfigurable pour un terminable bi-mode TDD et FDD de l'UMTS." Grenoble INPG, 2006. http://www.theses.fr/2006INPG0056.
Повний текст джерелаThe main objective of this thesis is the study of integration of several radio interfaces within the same radio architecture. The selected application is standard UMTS, where modes TDD and FDD are intended to be implemented on the same terminal with a low complexity thanks to the reconfigurability concept. First, we start to study the both UMTS access techniques in order to facilitate their common implementation on the same material support. This lead to establish a low complexity receiver composed by an adapted filters and an equalizer at symbol time. To improve the ability of theses Iwo treatments to fight against the interferences, a channel estimator was developed to provide a parametric model channel. An innovating reconfigurability concept is applied to obtain a reconfigurable hybrid receiver in spite of the difference between mode TDD and FDD. Finally, a decision entity improves the receiver flexibility by managing the resources of each treatment according to the state of the channel
Sron, Seng thail. "Algorithmes intelligents de pilotages d'antennes reconfigurables à partir de données en bande de base pour la norme LTE." Thesis, Limoges, 2015. http://www.theses.fr/2015LIMO0138.
Повний текст джерелаThe development of modal antennas which are radiation pattern reconfigurable active antennas, but not arrays, started in order to implement beam forming in cellphones. This solution is generally made with an antenna array, which is very difficult, even impossible, in a mobile phone. Beam forming could improve the link budget and increase the data rate. The first aim of this thesis is the development of modal antennas for LTE standard. Three modal antennas concepts were presented. The first one is a reconfigurable “folded loop” active antenna by permutation of feed and ground points. The second one is a solution to gather the main and the diversity antenna in the bottom part of the phone, and to support MIMO and carrier aggregation, which are two features of LTE. The last one optimizes the use of the second antenna in LTE MIMO systems in order to perform beam forming. These modal antennas will provide their real potential only by being used by a driving algorithm which will choose the best mode or configuration according to the situation. So, the second aim of this thesis is the development of smart modal antenna driving algorithms. The first algorithm, developed and patented by Ethertronics, has the specificity to predict, at each moment, which mode will be the best for the next moment, by using baseband data for LTE. The second algorithm is deterministic and can estimate and track the direction of arrival of the signal. Then, it selects the mode which has the best gain in this direction in order to improve the link budget
Hashim, Ghani. "Contribution à la réalisation et à la simplification des systèmes multivariables." Nancy 1, 1990. http://docnum.univ-lorraine.fr/public/SCD_T_1990_0029_HASHIM.pdf.
Повний текст джерелаVallée, Pascal. "Estimation du risque de chute suite à une perturbation d’équilibre." Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10261/document.
Повний текст джерелаFalling is the second most important cause of accidental deaths in the world. These falls lead to physical injuries and psychological consequences which limit mobility especially for the elderly. Being able to prevent these events appears to be crucial and a first mandatory step is to identify the risk of fall depending on the situation (slipping, hazardous environment …). The objective of this thesis is to propose numerical tools in order to link the risk of fall to the balance perturbation. In a first part, a simple numerical model estimates if initial unbalanced states can be recovered using one recovery step. Then a focus was made on external perturbations with a specific temporal profile close to public transportation perturbations. An experimental protocol was set up due to the lack of knowledge about these perturbations. The experiment investigated the effect of the perturbation parameters on the Balance Recovery (BR) threshold. An adjustment of the previous model was made to evaluate continuous perturbations and to compare its results against our experimental findings. The final chapter developed a complementary approach based on previous work using a model predictive control scheme which aims to regulate BR strategies. This whole work contributes to highlight the BR parameters which are difficult to assess during experimental procedures. It also points out the perturbation definition which is frequently incomplete in the literature although it is the phenomenon responsible for the BR process. In order to represent more realistic human behaviors some improvements can be done such as adding noncoplanar contacts or as integrating more detailed sensorimotor aspects
Kadri, Imen. "Controlled estimation algorithms of disparity map using a compensation compression scheme for stereoscopic image coding." Thesis, Paris 13, 2020. http://www.theses.fr/2020PA131002.
Повний текст джерелаNowadays, 3D technology is of ever growing demand because stereoscopic imagingcreate an immersion sensation. However, the price of this realistic representation is thedoubling of information needed for storage or transmission purpose compared to 2Dimage because a stereoscopic pair results from the generation of two views of the samescene. This thesis focused on stereoscopic image coding and in particular improving thedisparity map estimation when using the Disparity Compensated Compression (DCC)scheme.Classically, when using Block Matching algorithm with the DCC, a disparity mapis estimated between the left image and the right one. A predicted image is thencomputed.The difference between the original right view and its prediction is called theresidual error. This latter, after encoding and decoding, is injected to reconstruct theright view by compensation (i.e. refinement) . Our first developed algorithm takes intoaccount this refinement to estimate the disparity map. This gives a proof of conceptshowing that selecting disparity according to the compensated image instead of thepredicted one is more efficient. But this done at the expense of an increased numericalcomplexity. To deal with this shortcoming, a simplified modelling of how the JPEGcoder, exploiting the quantization of the DCT components, used for the residual erroryields with the compensation is proposed. In the last part, to select the disparity mapminimizing a joint bitrate-distortion metric is proposed. It is based on the bitrateneeded for encoding the disparity map and the distortion of the predicted view.This isby combining two existing stereoscopic image coding algorithms
Godard, Alexandre. "Espaces Lipschitz-libres, propriété (M) et lissité asymptotique." Paris 6, 2007. http://www.theses.fr/2007PA066438.
Повний текст джерелаZahaby, Mohamed El. "Contribution à la définition d'une norme des sites pollués : élaboration d'une méthodologie pour l'évaluation de la contamination d'un sol par éléments tracés." Vandoeuvre-les-Nancy, INPL, 1998. http://www.theses.fr/1998INPL045N.
Повний текст джерелаPorée, Fabienne. "Estimation et suivi de temps de retard pour la tomographie acoustique océanique." Phd thesis, Université Rennes 1, 2001. http://tel.archives-ouvertes.fr/tel-00439634.
Повний текст джерелаChevrié, Mathieu. "Modélisation électrothermique de composants électriques et électroniques automobiles et estimation des résistances de contact dans les connecteurs." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0079.
Повний текст джерелаAn automotive electrical connector contains electrical contact points subject to additional temperature rises by Joule effect caused by their contact resistances. The deterioration of a contact resistance can cause critical overheating at the contact points. This study proposes two approaches to detect abnormal changes in contact resistance. The first one, applied to an automotive electric case connector, relies on a model-based diagnosis to detect an abnormal variation in the contact resistance with respect to its nominal value. The second one, applied toan electric vehicle charging connector, consists in estimating a heat flow related to the Joule effect caused by the contact resistance. The value of the latter is then estimated using the least squares.These approaches rely on electrothermal models considered connectors and their environments.This study also presents the development of these models, including the optimization of the mesh of an electrical wire based on the minimization of the H2-norm of the error between ameshed integer order model and a reference analytical fractional order model
Sahraoui, Sélima. "Contribution à l'estimation des canaux relatifs aux signaux utile et interférent dans un système full-duplex dédié aux communications véhiculaires." Thesis, Valenciennes, 2019. http://www.theses.fr/2019VALE0008.
Повний текст джерелаIn this work of thesis, we propose new channel estimation approaches for a full-duplex system dédicated to vehicular communications. Both the self-interference (SI) and intended (SOI) channel are estimated. We propose different estimation méthods according to whether the pilots of the signals are transmitted jointly or separately. In the separate transmission, an estimation based on a new pilot configuration is proposed as well as a hybrid method which use both pilot configuration and training sequences.We also propose an optimisation of the conventional training-based method.It consists of improving the estimation of each training symbole. In the joint transmission, we propose two algorithms that aims to improve the estimation performances compared to the existing methods. In the first proposed method, the two channels are first estimated in the frequency domain using the Landweber iterations. The second proposition consists of using a projection matrix to manipulate only the pilots and avoid the noise that is caused by the SOI unknown datas. Finally, we propose a time and frequency-selective channel estimation for low and medium doppler frequency. Some of the proposed estimators are implemented on a real Full Duplex communication system which use Multi-reconfigurable antennas to perform the passive cancellation
Alam, Muhammad Mansoor. "Corrigé de localisation dans un environment extérieur sans fil en utilisant estimation, filtrage, la prévision et des techniques de fusion : une application par wifi utilisant le terrain à base de connaissances." Phd thesis, Université de La Rochelle, 2011. http://tel.archives-ouvertes.fr/tel-00815919.
Повний текст джерелаDumont, Thierry. "Contributions à la localisation intra-muros. De la modélisation à la calibration théorique et pratique d'estimateurs." Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00795685.
Повний текст джерелаSaideh, Michel. "Contributions on radio access techniques for future railway communications system." Thesis, Lille 1, 2019. http://www.theses.fr/2019LIL1I092.
Повний текст джерелаNowadays, a huge amount of data exchanges is needed in the railway system. This is particularly to support autonomous train, reduce operation and maintenance costs, increase safety and security. In the same time, many new services are offered to passengers. There is no unique technology that can satisfy all these needs. Consequently, different industrial and academical research projects are on-going at European and International levels to develop the Future Railway Mobile Communications System (FRMCS). FRMCS will be IP-based, adaptable, agnostic to radio technology and resilient to technological evolutions. In addition, it should support high data rate, low latency, large bandwidth, and efficient spectrum utilization. The FRMCS is expected to be able to choose in real time between different available radio access technologies in function of applications needs and the surrounding railway environment. Among these technologies, we can mention the Wi-Fi, LTE, satellites and the 5G NR standard in development. Thus, the contributions of this PhD thesis are part of the development of an Adaptable Communication System (ACS) for the railway by considering cutting-edge technologies of the future 5G NR system and beyond. Different key enabling technologies have been proposed recently under the umbrella of 5G and Beyond communication systems. Among which, radio access techniques play major role over key metrics, such as the efficient utilization of the available spectrum, the high data rates, and the computational complexity of the transceiver system. One of the major technological evolution in that domain concerns the introduction of different Multi-Carrier Modulation (MCM) and Non-Orthogonal Multiple Access (NOMA) techniques. In this Ph.D thesis, we start by considering the MCM technology in the context of high speed railway. A performance evaluation study is conducted where different MCM schemes are highlighted in different scenarios. The Filtered Bank Multi-Carrier (FBMC) waveform presents high robustness to high mobility scenarios while exploiting the available spectrum efficiently. However, FBMC advantages come with additional built-in interference that challenges traditional transceiver design techniques. Thereby, we propose different contributions that handle the channel estimation and equalization aspects of the FBMC waveform. The contributions aims to assure better performance at the cost of negligible additional complexity compared with the literature
Chaabane, Chiraz. "Système embarqué autonome en énergie pour objets mobiles communicants." Phd thesis, Université Nice Sophia Antipolis, 2014. http://tel.archives-ouvertes.fr/tel-01071056.
Повний текст джерелаChenu, Tournier Marc. "Contribution à l'utilisation des techniques de traitement d'antenne dans un système de radiocommunication numérique : application à l'UMTS et au GSM." Cachan, Ecole normale supérieure, 2000. http://www.theses.fr/2000DENS0039.
Повний текст джерелаKsenija, Doroslovački. "Generalizovana dijagonalna dominacija za blok matrice i mogućnosti njene primene." Phd thesis, Univerzitet u Novom Sadu, Fakultet tehničkih nauka u Novom Sadu, 2014. https://www.cris.uns.ac.rs/record.jsf?recordId=85475&source=NDLTD&language=en.
Повний текст джерелаThis thesis is related to matrices written in their block form. It systematizes known andrepresents new knowledge about properties of such matrices, which is based on the ideaof generalized diagonal dominance. Known results in the point case serve as a good basisfor block generalization, which is done in two different ways, the first one because of itssimple usability, and the other for capturing wider class of matrices which are treated.
Benali, Wissem. "Modélisation et optimisation de la consommation énergétique d'un système de communication Wi-Fi." Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2017. http://www.theses.fr/2017IMTA0041/document.
Повний текст джерелаThe strong increase of the number of connected devices in recent years and the increasing use of communication technologies has a significant impact on the energy bill. To stop the increase in energy consumption, it is essential to be able to compare the digital communication algorithms in terms of consumption, in order to develop the most energy-efficient transmission architecture.In this thesis, the IEEE 802.11ac Wi-Fi standard of physical layer is analyzed at an energy point of view. The power dissipated in the circuits for operating the signal processing algorithms is taken into account in addition to the antenna transmission power. The implemented methodology includes both simulations and developments on a hardware platform (FPGAs), resulting in more realistic consumption assessments.First, we analyzed separately the components of the digital communications chains. Then we integrated the periods of activity and inactivity of each element in the calculation of the global energy consumption of the chains. We propose a practical and efficient method of estimating consumption, including a database derived from simulations, and a theoretical analysis of the activity rates of each element of the chain.These results make it possible to analyze the distribution of the power consumption of the elements composing transmitters and receivers, and to compare various architectures and sets of parameters. In particular, we evaluated the impact of two Fast Fourier Transform architectures on overall system consumption
Mansour, Abdelouahab. "Résolution de deux types d’équations opératorielles et interactions." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1151/document.
Повний текст джерелаThe subject of this thesis focuses on the resolution of operator equationsin B(H) algebra of bounded linear operators on a Hilbert space. We studythose associated with generalized derivations. In this thesis, we also exploremore general equations such as the type AXB - XD = E or AXB -CXD = E where A, B, C, D and E belong to B(H). Specifically it is adescription of the solutions of these equations for E belongs in a precisefamily (Self-adjoint, normal, rank one, finite rank, compact, pair of FugledePutnam) and the operators A, B, C and D belonging to the good classesof operators (Those involved in applications , especially in physics) as theself-adjoint operators, normal operators, subnormal operators... Apart fromthe case where the spectra of A and B are disjoint, there is not any generalmethod for constructing effectively all solutions of the Sylvester equationAX - XB = C from the given operators A, B and C. One objective of thisthesis is to provide a constructive approach in when A, B and C belong toconventional families of operators. A spectral study of the solutions is alsostudied. Besides this qualitative study, there is also a quantitative study.It is also to obtain accurate estimates of the operator norm (or norm ofSchatten) of the solutions in terms of operator norms corresponding to data.This also led us to obtain results concerning some interesting inequalitiesfor generalized derivations, and finally some examples and properties ofoperators on a Banach space are also given
Kachenoura, Amar. "Traitement Aveugle de Signaux Biomédicaux." Phd thesis, Université Rennes 1, 2006. http://tel.archives-ouvertes.fr/tel-00359155.
Повний текст джерелаMaknun, Imam Jauhari. "Évaluation numérique des éléments finis DKMQ pour les plaques et les coques." Thesis, La Rochelle, 2015. http://www.theses.fr/2015LAROS040/document.
Повний текст джерелаIn the linear case, the Mindlin-Reissner model for thick plates and the Naghdi model for thick shells are commonly used. The finite element discretization of these models leads to numerical locking phenomenon when the thickness approaches zero : shear locking for plates and both shear and membrane locking for shells. There are some finite elements that could reduce or even eliminate this phenomenon. DKMQ element for plates or DKMQ24 element for shells, are low-order elements, based on a mixed formulation, introduced a few years ago to prevent the numerical locking phenomenon. In this thesis, we concentrated on numerical evaluation of the performance of these elements. Besides the classical benchmark tests, we also focused on the analysis of discrete inf-sup condition for DKMQ element. We studied the s-norm test proposed by Bathe for DKMQ24 element. Finally, we performed a posteriori error estimation for DKMQ and DKMQ24 elements, using the error estimator Z2 (proposed by Zienkiewicz and Zhu), associated with the averaging, projection or SPR recovery methods. The results obtained have enabled us to quantify the performance of these two finite elements for locking problems, and to identify their limits. Two important applications of these elements DKMQ and DKMQ24 were then presented ; the first one concerns thin-walled beams with open cross-section and the second one composite plates
Amamra, Abdelaziz. "Techniques d'estimation de la bande passante disponible de réseaux sans fil." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2008. http://tel.archives-ouvertes.fr/tel-00731123.
Повний текст джерелаKouassi, Boris Rodrigue. "Stratégies de coopération dans les réseaux radio cognitif." Phd thesis, Université Nice Sophia Antipolis, 2013. http://tel.archives-ouvertes.fr/tel-00921559.
Повний текст джерелаSEBE, Olivier. "Déconvolution aveugle et sismologie: estimation de la source sismique et des effets de site." Phd thesis, 2004. http://tel.archives-ouvertes.fr/tel-00010704.
Повний текст джерела