Dissertationen zum Thema „Différence de temps d’arrivée“
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Le, Minh Hoang. „Various Positioning Algorithms based on Received Signal Strength and/or Time/Direction (Difference) of Arrival for 2D and 3D Scenarios“. Electronic Thesis or Diss., Sorbonne université, 2022. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2022SORUS072.pdf.
Der volle Inhalt der QuelleLocalization has fascinated the researchers for centuries and has motivated a large amount of studies and developments in communications. The aim of positioning problems is to determine the position of the mobile device. Positioning algorithms can be divided into 3 methods: Trilateration, Multilateration and Triangulation. Trilateration utilizes the distances between the mobile device and all the base stations around to estimate the mobile position. These distances can be estimated via the Time of Arrival (ToA) or the Received Signal Strength (RSS). In Multilateration, the position location is based on measured quantities whose values are a function of the Time Difference of Arrival (TDoA) of the two ToAs. As for Triangulation, the directions of the incident signals play the most crucial role in the localization. Thus, it is also referred to as Direction-based Localization. The Direction of Arrival (DoA) of each incident wave is taken into account to solve the positioning problem. Each DoA is expressed by a single angle in 2D scenarios, and a pair of angles in 3D scenarios. There are noticeable differences between Network-Positioning and Self-Positioning. In Network-Positioning, the mobile device is directly localized based on the DoAs of the incident signals; meanwhile, in Self-Positioning, its position is estimated by the Direction Difference of Arrival (DDoA) between each pair of incident signals, because the DoA of each signal arriving to the Mobile Device is ambiguous. In this dissertation, we study all the localization approaches described above. Our spotlight is for Triangulation, which has many sub-scenarios to analyze. The results are obtained by MATLAB simulations
Pichette, Julien. „Imagerie de fluorescence et intrinsèque de milieux diffusants par temps d’arrivée des premiers photons“. Thèse, Université de Sherbrooke, 2014. http://savoirs.usherbrooke.ca/handle/11143/387.
Der volle Inhalt der QuelleMomméja, Adèle. „Les enfants d'immigrés au temps du droit à la différence : socio-histoire d'une politique compassionnelle“. Thesis, Paris 10, 2016. http://www.theses.fr/2016PA100086.
Der volle Inhalt der QuelleThis thesis analyses the invention, in the late 1970’s, of a « second generation problem » by a transnational network of experts, scholars and bureaucrats who gave increasing significance to a group which was still nowhere to be found, that is, not used as an ordinary self-identification category. It studies the borrowing of the “second generation” category form American sociology and the translation work conducted by experts to adapt it to the post-migratory European situation. It also investigates the appearance of a new knowledge adapted to the North African immigran children’s “specificities” and tries to understand the role of social sciences in the formation of an undefined social group. The research then focuses on the circulation of the “second generation” category between the public policy realm and the protests realm. We analyse the formation of protests behind closed doors which allowed claims on ethnic bases, and the emergence of spokespersons among the second generation. We seek to identify the emergence of new opportunities for a generation of immigrants’ children, by investigating simultaneously the activists’ careers in a diachronic perspective and the protests’ sequence of events in a pragmatic perspective. We finally address the biographical impact of a politics based on interpersonal bonds of recognition and disconnected from any measures against racial inequality. The troubles ex-activists had to recover from the end of protests and the confusion it generated are viewed as a consequence of a politics of compassion which nurtured hope but at the same time laid the foundation for its own failure
Kontogianni, Eleni. „Aristote, Heidegger : substance et temporalité, ou une histoire ancienne du temps“. Electronic Thesis or Diss., Strasbourg, 2022. http://www.theses.fr/2022STRAC004.
Der volle Inhalt der QuelleThe present study focuses on the concept of time, thematized by Aristotle who bequeathed to us the earliest concept of time with regard to its completeness, and by Heidegger who integrates Aristotle’s concept into the elaboration of a new concept of time, inseparable from the question of being as such, designated as temporality. One the one hand, the reconstruction of the Aristotelian concept of time is carried out under the double prism of Aristotelian cosmology and psychology, and leads to see that for Aristotle: 1) time is the formal aspect of movement, 2) time is the mathematical expression of the endurance of the substrate of movement. On the other hand, Heidegger’s opposition to the mathematization of movement by means of time signals the originality of his approach: time is prior to movement as the foundation of the constitution of the existing entity, the bearer of movement. However, the connection that Heidegger makes between time and being as such turns out to be problematic, insofar as the question of being implies the omission of the factor of matter on which the existing entity depends. The parallel study of these two concepts of time leads to discover in Aristotle a research that we may qualify as phenomenological physics: ‘physics’ because it takes matter into account; ‘phenomenological’ because it highlights the co-belonging of men and the universe as well as the complementarity between all its members
Bissoli, Nicolau Victor. „Performances de détection et de localisation des terminaux « SAR » dans le contexte de transition MEOSAR“. Phd thesis, Toulouse, INPT, 2014. http://oatao.univ-toulouse.fr/11301/1/bissoli_nicolau.pdf.
Der volle Inhalt der QuelleKeita, Moussa. „Allocation du temps et pauvreté : les enseignements du Programme Plateformes Mutifonctionnelles au Mali“. Thesis, Clermont-Ferrand 1, 2014. http://www.theses.fr/2014CLF10436/document.
Der volle Inhalt der QuelleNo abstract available
Cuni, Aude. „Effets électrostatiques sur les potentiels rédox des cofacteurs et leurs conséquences sur les transferts d'électron dans les centres réactionnels photosynthétiques. Exemples dans les centres réactionnels des bactéries pourpres et dans le photosystème II“. Paris 6, 2004. http://www.theses.fr/2004PA066073.
Der volle Inhalt der QuelleBadr, Maya. „Codage Espace Temps pour les canaux MIMO à accès multiple“. Phd thesis, Télécom ParisTech, 2010. http://pastel.archives-ouvertes.fr/pastel-00006005.
Der volle Inhalt der QuelleBadr, Maya. „Codage espace temps pour les canaux MIMO à accès multiple“. Phd thesis, Paris, Télécom ParisTech, 2010. https://pastel.hal.science/pastel-00006005.
Der volle Inhalt der QuelleExtensive research has been carried out these last few years on the single-user MIMO STBC design using advanced algebraic tools, namely cyclic division algebra. Families of single-user codes have been carefully constructed to achieve the DMT of the MIMO channel. Motivated by the promising results obtained in the single-user scenario, the aim of this thesis is to construct new families of multi-user STBCs. Multi-user MIMO (MU-MIMO) channels have recently attracted considerable attention because of its essential practical implication in today’s and future communication systems. The current study focuses on MIMO MAC where multiple users communicate with one receiver. A coherent communication system is considered, where the receiver has a perfect CSI while the transmitters do not have any CSI, but are aware of the channel statistics. The construction of the proposed multiple-access codes is based on an in-depth understanding of the information theoretic aspects of the MAC that give insight on the behavior of the channel. In order to simplify the problem, a MAC with single-antenna at the transmitters and an arbitrary number of antennas at the receiver is first considered in a synchronous and an asynchronous scenario. Next, the general MIMO-MAC with multiple-antenna at both the transmitters and the receiver is investigated. Finally, the multiple-access relay channel is considered, where one or more relays help the users communicate with the destination while the cooperation between the users is not allowed. In this case, we applied the code constructed for the MIMO MAC in a distributed way
Aulanier, Florian. „Tomographie acoustique océanique en guide d'ondes : de l'utilisation des temps à celle des angles“. Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENU031/document.
Der volle Inhalt der QuelleIn the ocean, temperature changes induce sound-speed perturbations. Ocean acoustic tomography uses the fluctuations of recorded acoustic signals, to map those sound-speed perturbations. To this end, sound-speed perturbations are classically related to the acoustic-wave travel-times measured on the records. This study suggests an alternative method to perform acoustic thermometry based on acoustic-wave propagation directions. It allows imaging a shallow-water waveguide (~100 m), at small scale (1 to 10 km), with high spatial resolution (10 m in range, 2 m in depth). In this context, wideband (~1.5 kHz) low frequency (~1 kHz) acoustic waves propagates along multiple paths similar to spatially « fat » geometrical rays. Using a pair of arrays (source/receiver) and the double-beamforming processing to separate acoustic signals coming from different paths and measure their: travel-time (TT), directions-of-arrival (DOA) and directions-of-departure (DOD). Under the hypothesis of small perturbations, TP, DOA and DOD variations are linearly related to sound-speed perturbations in an analytical way. This formulation based on Born's diffraction physics at the first order uses kernel functions called: the time-angle sensitivity kernels (T-A-SK). The T-A-SK model is then combined to classical inversion methods to retrieve sound-speed perturbations from TT, DOA and DOD variations. The methods developed here have been validated on simulated data, and applied on real small-scale data coming from the ultrasonic tank of the ISTerre, Grenoble
Blanchet, L. „Méthodes de résolution dédiées à l'étude spectroscopique de processus photoinduits. Adaptation aux spécificités des spectres résolus en temps“. Phd thesis, Université des Sciences et Technologie de Lille - Lille I, 2008. http://tel.archives-ouvertes.fr/tel-00353553.
Der volle Inhalt der QuelleKeita, Moussa. „Allocation du temps et pauvreté: les enseignements du Programme Plateformes Multifonctionnelles au Mali“. Phd thesis, Université d'Auvergne - Clermont-Ferrand I, 2014. http://tel.archives-ouvertes.fr/tel-01015787.
Der volle Inhalt der QuelleStanciu, Mihai Ionut. „Sur l'estimation aveugle de paramètres de signaux UWB impulsionnels dans un contexte de radio intelligente“. Brest, 2011. http://www.theses.fr/2011BRES2023.
Der volle Inhalt der QuelleThis thesis is concerned with the study of UWB systems which represent a promising perspective in low range radio systems field. UWB technology is best suited to be used within ad-hoc Piconet radio networks, which must dispose of high flexibility. Consequently this thesis is focused on one hand on the development of very low complexity parameters blind estimation methods, which can play an essential role in the synchronization stage, and on the other hand on the statistical characterization of the propagation channel, with the scope of establishing criteria to realize blind real time adjustments of the digital transmission. The study is organized in three main directions. The first consists of developing a method to estimate the chip time, based on noisy times of arrival measurements, with false and missing observations. The main problem with this approach is that the considered times of arrival statistical model cannot realistically reflect indoor UWB channels. Therefore a second direction is concerned with the development of a method to estimate the chip time based on energy measurements on the received UWB impulse radio signal. Using the well known energy detector principle this approach jointly estimates the chip time and this optimal integration window, the main advantage is that it allows considering propagation noise, multipath propagation and multiuser interference. The third direction deals with a statistical study of the multipath propagation interference of a UWB propagation channel
Mayorquim, Jorge Luiz. „Étude en vue de la réalisation d'un réseau de neurones binaires logiques : détection de contours en temps réel“. Compiègne, 1996. http://www.theses.fr/1996COMPD893.
Der volle Inhalt der QuelleJoubaud, Thomas. „Prédiction objective de l'effet des systèmes tactiques de communication et protection sur les performances de localisation sonore“. Thesis, Paris, CNAM, 2017. http://www.theses.fr/2017CNAM1132/document.
Der volle Inhalt der QuelleIn many civilian or military situations, hearing protection is of major importance. The listener's acoustical situational awareness must however also be preserved. Tactical Communication and Protective Systems (TCAPS) are hearing protection devices that sufficiently protect the listener's ears from hazardous sounds and preserve speech intelligibility, thus allowing low-level speech communication. However, previous studies demonstrated that TCAPS still deteriorate the listener's situational awareness, in particular the ability to locate sound sources. On the horizontal plane, this is mainly explained by the degradation of the acoustical cues normally preventing the listener from making front-back confusions. In the present PhD work, a behavioral sound localization experiment is conducted with six TCAPS: two passive and two active earplugs, and two active earmuffs. The performance in open ear condition is not retrieved with any protector, but the experiment ranks the TCAPS by type: passive earplugs lead to better performance than active earplugs, and active earmuffs induce the worst performance. As part of TCAPS development and assessment, a method predicting the protector-induced degradation of the sound localization capability, and based on electroacoustic measurements, would be more suitable than time-consuming behavioral experiments. In this context, two methods based on Head-Related Transfer Functions (HRTFs) measured on an artificial head are investigated: a template-matching model and a three-layer neural network. They are optimized to fit human sound localization performance in open ear condition. The methods are applied to the HRTFs measured with the six TCAPS, providing position-dependent localization probabilities. Compared with the behavioral results, the neural network predicts realistic performances with earplugs, but overestimates errors with earmuffs. The template-matching model predicts human performance well. However, the likelihood of the resulting probability distributions with the behavioral observations is lower than that of the neural network. Finally, both methods developed in this study are independent of the artificial head used, and can be applied to assess not only TCAPS prototypes, but also hearing aids
Jain, Ankit. „Detection on HF radio transmitters using passive geolocation techniques“. Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2019. http://www.theses.fr/2019IMTA0128/document.
Der volle Inhalt der QuelleLong-range radio transmission in the HF band can cover large geographical areas using light and mobile equipment. It is therefore well suited for communications during military operations orfor the rapid deployment of an agile communication network during humanitarian operations. In this context, it is important to determine the geographic location of the transmitters by analyzing the electromagnetic communication signals. The aim of the thesis is to develop an alternative, complementary geolocation technique, entitled Time Difference of Arrival (TDoA) that has rarely been studied in the case of ionospheric propagation. As a first step, HF geolocation algorithm based on TDoA is setup and analyzed by parametric software simulations. Simulation results demonstrate that increasing the number of receivers leads to a significant improvement in the geolocation accuracy. In order to study the feasibility of a practical HF geolocation system based on TDoA, multiple remotely controllable HF receivers are designed using software defined radio (SDR) modules and a country wide operational receiver network is deployed in France. A concept of cross-channel sounding along with its mathematical description is proposed to evaluate the propagation duration differences between the signals captured by two distinct receivers. Preliminary experimental results show that it is possible to locate the HF transmitters under favorable conditions with a relative geolocation error ranging from about 0.1 to 10% of the actual ground distance. Data captured during the large scale measurement campaign are analyzed statistically to evaluate the performance of the geolocation algorithm and define parameters that could be considered in an operational approach
Pardiñas, Mir Jorge Arturo. „Contribution à l'étude de la détection des signaux UWB. Etude et implémentation d'un récepteur ad hoc multicapteurs. Applications indoor de localisation“. Electronic Thesis or Diss., Evry, Institut national des télécommunications, 2012. http://www.theses.fr/2012TELE0052.
Der volle Inhalt der QuelleThis thesis is part of the Electronics and Physics (EPH) department’s research work at Institut Telecom SudParis in collaboration with the Information, Images and Information Processing (CITI) Department. The project included the development of a receiver architecture called Time Delayed Sampling and Correlation (TDSC) that works with Transmitted Reference Ultra Wideband signals (TR-UWB), and which could achieve a good performance without channel estimation. The first part of this work included the design of a modular UWB communication system based on the TDSC method. This platform uses a 0.35μm CMOS chip conceived by the EPH laboratory. This gives the possibility to record real TR-UWB signals and to achieve functional tests. A second part of the thesis was to deepen the use of the TDSC method for detection of UWB signals and the synchronization procedure of the receiver using real signals acquired by the platform. A series of tests were conducted in this regard by using baseband signals as well as frequency translated signals, through cable channels and radio transmission. The results let us validate the TDSC detection and the synchronization procedure. Finally, a third line of work was the study and development of a distance estimation proposal based on the time of arrival (TOA) of TR-UWB signals, for indoor localization purposes. The study included a synthesis of several proposals and experimental works. Simulations were made and compared with other methods. Experimental results and their good convergence with the simulations let conclude that the proposal is a feasible solution to the measurement of the TOA, based on a TR-UWB receiver with low-complexity architecture
Khawam, Kinda. „L'ordonnancement opportuniste dans les réseaux mobiles de nouvelle génération“. Paris, ENST, 2006. http://www.theses.fr/2006ENST0030.
Der volle Inhalt der QuelleThe scarce resources in wireless systems compounded by their highly variable and error prone propagation characteristics stress the need for efficient resource management. Scheduling is a key tool to allocate efficiently the radio frequency spectrum. While fading effects have long been combated in wireless networks, primarily devoted to voice calls, they are now seen as an opportunity to increase the capacity of novel wireless networks that incorporate data traffic. For data applications, there is a service flexibility afforded by the delay tolerance of elastic traffic and by their ability to adapt their rate to the variable channel quality. Channel-aware scheduling exploit these characteristics by making use of channel state information to ensure that transmission occurs when radio conditions are most favourable. When users have heterogeneous characteristics and quality of service requirements, channel-aware scheduling becomes a challenging task. In this thesis, channel-aware transmission schemes for supporting downlink non-real time services are proposed and analyzed for novel cellular systems. The proposed schemes are designed for providing various QoS requirements for users while increasing the system global throughput
Pardiñas, Mir Jorge Arturo. „Contribution à l'étude de la détection des signaux UWB. Etude et implémentation d'un récepteur ad hoc multicapteurs. Applications indoor de localisation“. Phd thesis, Institut National des Télécommunications, 2012. http://tel.archives-ouvertes.fr/tel-00814663.
Der volle Inhalt der QuelleBocquet, Michael. „Contribution à la mise en place d'une plateforme de communication et de localisation en technologie ultra large bande en gamme millimétrique“. Lille 1, 2007. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2007/50376-2007-Bocquet.pdf.
Der volle Inhalt der QuelleDubrovskaya, Anna. „Sortie d'une temporalité suspendue : entre le parental et le fraternel : le sujet en quête des repères oedipiens“. Thesis, Nice, 2014. http://www.theses.fr/2014NICE2017.
Der volle Inhalt der QuelleThe current social link mutation raises multiple issues about its impact on the subjectivity processes. Considering this we studied identity’s construction of children and teenagers, and in particular oedipal problematic and connected questions: identifications, oedipal promise and temporality. Using projective tests (drawings and « Pattenoire Test ») these processeswere investigated among 5-15 years old French children. Peer figure appeared in our results as a main identification reference and relationship with parents keeps archaic pre-oedipal nature. This horizontal link complicates the access to the difference between the generations and to the psychical temporality as well. Thus Oedipus complex « bug » troubles the development of the «transitional» capacity which gives access to the creativity. Thisphenomenon is especially evident at the teenage, when subject has now to seek for new arrangements to get out of the temporality suspended to the relationship with parents in the imaginary register
Jauréguy, Maïté. „Étude de la diffraction par impulsions électromagnétiques très courtes d'objets en espace libre ou enfouis : modélisation numérique et extraction des paramètres caractéristiques“. Toulouse, ENSAE, 1995. http://www.theses.fr/1995ESAE0015.
Der volle Inhalt der QuelleNasreddine, Jad. „Allocation de ressources radios dans les systèmes UMTS à duplexage temporel“. Rennes 1, 2005. http://www.theses.fr/2005REN1S009.
Der volle Inhalt der QuelleDeza, Guadalupe. „Clinique et critique de la mémoire : Deleuze et l'Argentine“. Thesis, Paris 8, 2019. http://www.theses.fr/2019PA080013.
Der volle Inhalt der QuelleInscribed in a philosophical reflection on time and its dynamics, this research deals with the hegemonic representation of the concept of memory of the State terrorism in Argentina, and proposes a critique of it based on the philosophy of Gilles Deleuze.When a traumatic event acts as a turning point in a lifetime; when we are confronted with the experience of a time out of control, whose duration follows the rhythm marked by the event; when the veracity of the memory loses all interest in the face of the commotion and the metamorphosis of the subjectivity that it provokes; that is when the questions emerge: What is memory? What is the past and how to preserve it for us?In the horizon outlined by these questions, this work tries to put in practice, through the introduction of the Deleuzian philosophy in the field of memory studies, a critique of the uses and ways of understanding the notion of memory. The link that our work establishes between these fields of thought so far split, complicates the current understanding of the concept of memory in Argentina, while proposing new landscapes to be explored based on Deleuze's philosophy. In this way, this thesis proposes a reading of Deleuze's work marked by a regional perspective, and a theoretical opening to other possible - and deeply problematic - ways of thinking about the concept of memory
Inscripta en una reflexión filosófica sobre el tiempo y su dinámica, esta investigación trata sobre la representación hegemónica del concepto de memoria del terrorismo de Estado en Argentina, y propone una crítica de la misma a partir de la filosofía de Gilles Deleuze.Cuando un acontecimiento traumático hace las veces de bisagra en el tiempo de una vida; cuando nos vemos confrontados a la experiencia de un tiempo fuera de quicio, cuya duración sigue el ritmo marcado por el acontecimiento; cuando la veracidad del recuerdo pierde todo interés frente a la conmoción y a la metamorfosis de la subjetividad que suscita; es entonces cuando emergen las preguntas: ¿qué es la memoria? ¿Qué es el pasado y cómo conservarlo para nosotros? En el horizonte trazado por estas cuestiones, el análisis propuesto en este trabajo procura poner en práctica, a través de la introducción de la filosofía deleuziana en el ámbito de los estudios de memoria, una crítica de los usos y de las maneras de comprender la noción de memoria. El vínculo que nuestro trabajo establece entre estos dominios del pensamiento hasta ahora escindidos, complejiza la comprensión corriente del concepto de memoria en Argentina, al mismo tiempo que propone nuevos paisajes a explorar a partir de la filosofía de Deleuze. De este modo, esta tesis propone una lectura marcada por una perspectiva regional de la obra de Deleuze, y una apertura teórica a otras maneras posibles –y profundamente problemáticas– de pensar en el concepto de memoria
Dagallier, Adrien. „Modeling acoustic impulse arrivals for shot localization in complex environments“. Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEC034.
Der volle Inhalt der QuelleBattlefield acoustics sensing systems have been used since the early 20th century for detection and localization of threats. Artillery and gun shots emit loud sounds (muzzle blast upon firing, ballistic wave emitted by the supersonic projectile, possible impact burst) which propagate at long ranges. These sounds may be recorded at low-cost, passive, all-weather, omnidirectional sensors, usually distributed over the monitored area. Sensor data are then fused, using localization algorithms and propagation models to relate observed features, e.g. times of arrival (TOAs) or spectra, to a plausible source position. The originality of the team’s approach, through the Matching method, consists in factoring in the physics of propagation: wind and temperature effects, obstacles... A database of virtual sources acoustic features is numerically predicted at a set of sensors. Upon detection of an event, observed features are evaluated against the database. The estimated sound source position is that of the closest match. In practice, TOAs of signals at synchronous, distributed sensors are sufficient for localization of e.g., sniper shots in urban areas. The database may be generated in advance, while the Matching is potentially real-time. Localization is robust to noise, sensor positioning, calibration, or environment data errors. However, building the database is computer-intensive, and handling of non-trivial geometries or sources is challenging. Integration of environment data, feasibility of artillery shot localization and of Matching multiple arrivals, are open questions. The rationale of the present work is to develop a modeling suite, from procurement of terrain and atmosphere data, to shot ballistics and acoustic propagation, to compute TOAs of the acoustic emissions of supersonic shots in a consistent and physics-based fashion. Each time, limiting factors (sensor position error, atmospheric data accuracy, ballistic dispersion...) are determined, and all models are consequently refined, or simplified, to the befitting level of detail for the Matching phase. More specifically, a Fast-Marching acoustic propagation model is derived and implemented (IFM). IFM retains the physical generality of 3D+time solvers, while computing only TOAs and thus being much faster. IFM handles urban geometries with unstructured meshes, and long range propagation with terrain-following grids. Coupling to a ballistic model accounts for sound emissions of supersonic shots. Bullet hits in building façades or the ground and 3D aerodynamic effects for large caliber projectiles are considered. IFM is then coupled to computational fluid dynamics or meso-scale numerical weather prediction models to determine relevant atmospheric inputs in support or replacement of on-site measurements. Two measurement campaigns were conducted for evaluation of the approach in built-up areas, including supersonic weapons and actual live ammunition. Point source localization performance is state-of-the-art with down to 4 sensors. Sniper localization performs well with down to 6 sensors, including fully non-line-of-sight sensors configurations - which is to our knowledge a first for countersniper systems. Localization of artillery shots is demonstrated on the multiple arrivals of measured artillery signals, from a small baseline array, with little influence of the array geometry on the sensing performance, thanks to the accuracy of the predicted muzzle blast, ballistic wave and impact burst TOAs. Again, this is to our knowledge a first. The modeling suite developed in this work may readily assess the performance of any synchronous, TOA-based sensing system in realistic scenarii, in arbitrarily complex, nonline- of-sight environments - with a common framework for both counter-sniper and counter artillery systems. It could also be used as a decision aid, to choose the most fitting sensor configuration for surveillance of a given area, in a given scenario
Zhang, Lin-Bo. „Un schéma de semi-discrétisation en temps pour des systèmes différentiels discrétisés en espace par la méthode de Fourier : résolution numérique des équations de Navier-Stokes stationnaires par la méthode multigrille“. Paris 11, 1987. http://www.theses.fr/1987PA112352.
Der volle Inhalt der QuelleThis work contains two independant parts. In the first part, we introduce a semi-discretization scheme for ordinary diferential systems whose linear part is diagonal (Fourier apprroximation of problèms with periodical boundary conditions in space yields often this kind of system). This scheme generalizes the classical Adams-Bashforth-Moulton scheme. We apply it to Kuramoto-Sivashinski equation and Navier-Stokes equations with periodical boundary conditions. In the second part, we present a second-order upwinding finite difference scheme for the steady Navier-Stokes equations and we solve the resulting discrete system by a multigrid method. Calculations have been carried out for the driven cavity problem in which the second-order scheme has been compared to a first-order upwinding scheme. Results have been obtained for Reynolds numbers up to 10 000 and compared to those published in the literature
Boudjellal, Abdelouahab. „Contributions à la localisation et à la séparation de sources“. Thesis, Orléans, 2015. http://www.theses.fr/2015ORLE2063.
Der volle Inhalt der QuelleSignal detection, localization, and separation problems date back to the beginning of the twentieth century. Nowadays, this subject is still a hot topic receiving more and more attention, notably with the rapid growth of wireless communication systems that arose in the last two decades and it turns out that many challenging aspects remain poorly addressed by the available literature relative to this subject. This thesis deals with signal detection, localization using temporal or directional measurements, and separation of dependent source signals. The main objective is to make use of some available priors about the source signals such as sparsity, cyclo-stationarity, non-circularity, constant modulus, autoregressive structure or training sequences in a cooperative framework. The first part is devoted to the analysis of (i) signal’s time-of-arrival estimation using a new minimum error rate based detector, (ii) noise power estimation using an improved order-statistics estimator and (iii) side information impact on direction-of-arrival estimation accuracy and resolution. In the second part, the source separation problem is investigated at the light of different priors about the original sources. Three kinds of prior have been considered : (i) separation of constant modulus communication signals, (ii) separation of dependent source signals knowing their dependency structure and (iii) separation of dependent autoregressive sources knowing their autoregressive structure
Deleuze, Anne-Laure. „Contributions à l'étude des systèmes ultra large bande par impulsions“. Phd thesis, Télécom ParisTech, 2006. http://pastel.archives-ouvertes.fr/pastel-00001668.
Der volle Inhalt der QuelleBeaubois, Florian. „Positionnement d'une balise sous-marine en environnement peu profond“. Thesis, Littoral, 2016. http://www.theses.fr/2016DUNK0423/document.
Der volle Inhalt der QuelleThe purpose of that thesis work is the research and implementation of a compact and simple underwater localization system that aim to be used in ports, coastal areas and other low-depth environments. Our system is SBL (Small Distance Baseline), with a small number of transceivers (only one emitter and two hydrophones). Due to the system's geometric configuration not being optimal (both hydrophones are close to one another), the precision obtained using classical approaches is poor. We therefore propose a new localization approach that will improve it. The emitter we wish to localize emit a spread spectrum signal. The time difference of arrival (TDOA) between the two hydrophones is then determined using correlations methods. We propose in our work two tracking loops that will estimate both the delay and the doppler frequency between the signals. Using a Kalman filter , those methods are implemented respectively in open and close loop. From each TDOA measurement, we can calculatea hyperbolic area of possible emitter location. We thus use a statistical model which takes into account the local geometry of our measurements system in order to create a probable localization area around each hyperbole. By using the measurements at several different boat positions, we create a probability density whose maximum will be centered around the emitter's position. We show that, on simulated data, it is possible to localize the beacon with a precision beneath a meter with a realistic noise level. Experimental work and real data collection confirm that the method can in that context achieve the same result with a precision of a few meters
Marinescu, Paul. „La problématique de l'universalité de l'herméneutique“. Thesis, Lyon 3, 2011. http://www.theses.fr/2011LYO30036.
Der volle Inhalt der QuelleBy taking as starting point the famous debates from the 70s and the 80s around the universality of hermeneutics, which had inflamed some of the 20th century greatest thinkers, such as Hans-Georg Gadamer, Jürgen Habermas et Jacques Derrida, this PhD thesis attempts to identify the actual philosophical question behind the hermeneutics’ claim of universality: the time’s hermeneutical intelligibility. I strive to express this intelligibility, which translates the paradoxical articulation of time and being as difference, by proposing an interpretation of two essential “figures” for the thinking of Martin Heidegger and Hans-Georg Gadamer: “the forgetting of being” and “the temporal distance”. More precisely, this interpretation or, as I call it, “figural reading” intends to understand the time’s paradoxical way of engendering the hermeneutical difference, that is: its capacity to generate simultaneously the occultation and the revealing of meaning, its potential to give the surplus of meaning and, at the same time, the finitude of comprehension. As a result of this figural reading, I conclude that the hermeneutics has its worth in interrogating the phenomenon of the difference between understanding and misunderstanding, and more precisely in identifying, as a foregoing condition of this difference’s effectivity, the time’s hermeneutical intelligibility. Finally, the hermeneutical universality reveals its genuine temporal nature: taken as a “productive aspect of the temporality”, it merges into the dynamics “of what is to be understood”
Tranchant, Thibault. „Raison et création : le constructivisme et l’institutionnalisme postmétaphysiques de Cornelius Castoriadis“. Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1S040/document.
Der volle Inhalt der QuelleThe purpose of this doctoral thesis is to expose Castoriadis’ poïetical and institutional answer to the following question: how can we constitute a practical universality in a postmetaphysical context. Starting with a definition of political philosophy as the progressive and institutional objectification of reason, I first show how the modern radical critic of metaphysical thoughts and the modern emergence of a procedural conception of reason were both problematic for political philosophy. The thesis is then divided into two parts. The first part is devoted to Castoriadis’ philosophy and presents his own critics of metaphysical thinking, his ontology and his theory of knowledge. I then follow the interpretative thesis according to which Castoriadis’ philosophy can be characterized as an ''ontopoïetical pluralistic constructivism'' The second part is about his conception of practical reason, which I interpret as a “postmetaphysical institutionalism”. I conclude by showing that Castoriadis offers not only new mediations between politics and philosophy but also an original conception of practical universality in the history of political philosophy. Using a comparative method, I put forward Castoriadis’ thoughts through a comparison with other philosophies that share common problems and thesis, e.g. the Hegelian-Marxian tradition and the philosophies of difference
Lapointe, Francis. „L'expérience éthique : essai pour une critique phénoménologique de l'éthique comme illustration du vivre-ensemble“. Mémoire, 2008. http://www.archipel.uqam.ca/2033/1/M10533.pdf.
Der volle Inhalt der QuelleLiénart, Cécile. „Concilier travail et famille : l'adéquation entre les politiques et la situation des travailleuses atypiques au Québec“. Mémoire, 2011. http://www.archipel.uqam.ca/4126/2/M12139.pdf.
Der volle Inhalt der QuelleRivest, François. „Modèle informatique du coapprentissage des ganglions de la base et du cortex : l'apprentissage par renforcement et le développement de représentations“. Thèse, 2009. http://hdl.handle.net/1866/4309.
Der volle Inhalt der QuelleThroughout lifetime, the brain develops abstract representations of its environment that allow the individual to maximize his benefits. How these representations are developed while trying to acquire rewards remains a mystery. It is reasonable to assume that these representations arise in the cortex and that the basal ganglia are playing an important role in reward maximization. In particular, dopaminergic neurons appear to code a reward prediction error signal. This thesis studies the problem by constructing, using machine learning tools, a computational model that incorporates a number of relevant neurophysiological findings. After an introduction to the machine learning framework and to some of its algorithms, an overview of learning in psychology and neuroscience, and a review of models of learning in the basal ganglia, the thesis comprises three papers. The first article shows that it is possible to learn a better representation of the inputs while learning to maximize reward. The second paper addresses the important and still unresolved problem of the representation of time in the brain. The paper shows that a time representation can be acquired automatically in an artificial neural network acting like a working memory. The representation learned by the model closely resembles the activity of cortical neurons in similar tasks. Moreover, the model shows that the reward prediction error signal could accelerate the development of the temporal representation. Finally, it shows that if such a learned representation exists in the cortex, it could provide the necessary information to the basal ganglia to explain the dopaminergic signal. The third article evaluates the explanatory and predictive power of the model on the effects of differences in task conditions such as the presence or absence of a stimulus (classical versus trace conditioning) while waiting for the reward. Beyond making interesting predictions relevant to the timing literature, the paper reveals some shortcomings of the model that will need to be resolved. In summary, this thesis extends current models of reinforcement learning of the basal ganglia and the dopaminergic system to the concurrent development of representation in the cortex and to the interactions between these two regions.