Дисертації з теми "Cartographie de réplication optique"
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Menezes, Braganca Nikita. "Cartographie pangénomique à haut débit et en molécule unique de la réplication de l'ADN." Electronic Thesis or Diss., Paris Sciences et Lettres (ComUE), 2019. http://www.theses.fr/2019PSLEE040.
Повний текст джерелаDNA replication is a vital process ensuring accurate conveyance of the genetic information to the daughter cells. In eukaryotic organisms, genome replication is carried out by using multiple start sites, also known as replication origins. In metazoans, the mapping of replication remains challenging. Genome wide mapping of human replication origins performed using sequencing techniques only modestly agree. These existing genome wide approaches use large cell populations that smooth out variability between chromosomal copies that could explain this inconsistency. Thus, to get a better understanding of DNA replication and to uncover the cell-to-cell variability, the development of single molecule techniques is fundamental. DNA combing, a widespread technique used to map DNA replication at a single molecule level, is refractory to automation, forestalling genome-wide analysis. To overcome these impediments, we repurposed an optical DNA mapping device based on microfluidics, the Bionano Genomics Irys system, for High-throughput Optical MApping of Replicating DNA (HOMARD). We typically collect, for a single run, over 34 000 images and more than 63 000 Mbp of DNA. Our new open source tools, that required the adaptation of the provided proprietary software, empower us to simultaneously visualize the intensity profiles of all mapped DNA molecules, check the optical mapping performed and, in particular, see where the replication tracks are located genome-wide at a single molecule level. We demonstrate the robustness of our approach by providing an ultra-high coverage (23,311 x) replication map of bacteriophage DNA in Xenopus egg extracts and the potential of the Irys system for DNA replication and other functional genomic studies apart from its standard use
Wang, Weitao. "Genome-Wide Mapping of Human DNA Replication by Optical Replication Mapping Supports a Stochastic Model of Eukaryotic Replication." Electronic Thesis or Diss., Université Paris sciences et lettres, 2021. http://www.theses.fr/2021UPSLS048.
Повний текст джерелаDNA replication is regulated by the location and timing of replication initiation. Therefore, much effort has been invested in identifying and analyzing the sites of human replication initiation. However, the heterogeneous nature of eukaryotic replication kinetics and the low efficiency of individual initiation site utilization in metazoans has made mapping the location and timing of replication initiation in human cells difficult. A potential solution to the problem of human replication mapping is single-molecule analysis. However, current approaches do not provide the throughput required for genome-wide experiments. To address this challenge, we have developed Optical Replication Mapping (ORM), a high-throughput single-molecule approach to map newly replicated DNA and used it to map early initiation events in human cells. The single-molecule nature of our data, and a total of more than 2000-fold coverage of the human genome on 27 million fibers averaging ~300 kb in length, allow us to identify initiation sites and their firing probability with high confidence. In particular, for the first time, we are able to measure genome-wide the absolute efficiency of human replication initiation. We find that the distribution of human replication initiation is consistent with inefficient, stochastic initiation of heterogeneously distributed potential initiation complexes enriched in accessible chromatin. In particular, we find sites of human replication initiation are not confined to well-defined replication origins but are instead distributed across broad initiation zones consisting of many initiation sites. Furthermore, we find no correlation of initiation events between neighboring initiation zones. Although most early initiation events occur in early-replicating regions of the genome, a significant number occur in late replicating regions. The fact that initiation sites in typically late-replicating regions. The fact that initiation sites in typically late-replicating regions have some probability of firing in early S phase suggests that the major difference between initiation events in early and late replicating regions is their intrinsic probability of firing, as opposed to a qualitative difference in their firing-time distributions. Moreover, modeling of replication kinetics demonstrates that measuring the efficiency of initiation-zone firing in early S phase suffices to predict the average firing time of such initiation zones throughout S phase, further suggesting that the differences between the firing times of early and late initiation zones are quantitative, rather than qualitative. These observations are consistent with stochastic models of initiation-timing regulation and suggest that stochastic regulation of replication kinetics is a fundamental feature of eukaryotic replication, conserved from yeast to humans
Saulebekova, Dalila. "Study of DNA replication program of the human genome by high–throughput single-molecule Optical Replication Mapping." Electronic Thesis or Diss., Sorbonne université, 2024. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2024SORUS185.pdf.
Повний текст джерелаDNA replication is a crucial cellular process, ensuring that each cell division results in an accurate duplication of genome composed of > 6 billion base pairs in humans. This process relies on the precise activation of thousands of replication origins in a defined temporal order called Replication Timing (RT) program. This program is tightly linked to chromatin organization and its deregulation can lead to genome instability, mutations and development of diseases, such as cancer. However, heterogeneous and stochastic nature of origins activation in mammalian cells poses significant challenges to our understanding of DNA replication initiation in humans. Chromatin organization and RT are intricately linked to genome function, with theevolutionary conserved protein RIF1 playing a key role in controlling these processes. Although the importance of RIF1 in regulating the timing of DNA replication and the chromatin organization is well studied, whether RIF1 affects the location and efficiency of replication initiation sites remained unclear. In this work, to investigate the detailed impact of RIF1 on replication origins initiation and dynamics, we applied Optical Replication Mapping, (ORM) - a high-throughput, single-molecule approach recently developed by our team, that combines the fluorescent detection of in vivo labelled active origins over long individual DNA molecules and their optical mapping to the genome using Bionano Genomics technology. Our results obtained from early S-phase HCT116 cells addresses the research gap by demonstrating that RIF1 depletion let to a dramatic change in origin location and firing efficiency, showing a more homogeneous firing across the genome, and challenging previous assumptions about replication origin specificity and efficiency. Notably, our enhanced ORM approach enabled the discovery of large number of new origins activated upon the depletion of RIF1, alongside a detailed characterization of the associated histone modification patterns. Our results also uncover the differences in origins initiation in relation to the newly classified chromatin states: we observed that the absence of RIF1 did not uniformly impact all chromatin states. Specifically, RIF1 depletion significantly enhances the replication initiation in the newly characterized B0 state, characterized by enriched H3K9me2 and H2A.Z and neutral interaction preferences for A and B compartments, and minimally affects the late-replicating B4 heterochromatin. To advance the study of late replication regions, we have upgraded the ORM method by improving the labelling efficiency that allowed us to compute a high-resolution Replication Fork Directionality profile (RFD) directly from the asynchronized cells. RFD profiles revealed the initiation dynamics in late regions including Common Fragile Sites (CFSs) and confirmed that the activation of previously absent late replication origins. Through combination of multi-omics and ORM approaches, this work for the first time demonstrates that RIF1 not only alters RT but it's absence also leads to the activation of new origins, providing an important support for further dissecting the molecular mechanisms governing DNA replication and genome organization
Ravon, Gwladys. "Problèmes inverses pour la cartographie optique cardiaque." Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0118/document.
Повний текст джерелаSince the 80's optical mapping has become an important tool for the study and the understanding of cardiac arythmias. This experiment allows the visualization of fluorescence fluxes through tissue surface. The fluorescence is directly related to the transmembrane potential. Information about its three-dimension distribution is hidden in the data on the surfaces. Our aim is to exploit this surface measurements to reconstruct the depolarization front in the thickness. For that purpose we developed a method based on the resolution of an inverse problem. The forward problem is made of two diffusion equations and the parametrization of the wavefront. The inverse problem resolution enables the identification of the front characteristics. The method has been tested on in silico data with different ways to parameter the front (expanding sphere, eikonal equation). The obtained results are very satisfying, and compared to a method derived by Khait et al. [1]. Moving to experimental data put in light an incoherence in the model. We detail the possible causes we explored to improve the model : constant illumination, optical parameters, accuracy of the diffusion approximation. Several inverse problems are considered in this manuscript, that involves several cost functions and associated gradients. For each case, the calculation of the gradient is explicit, often with the gradient method. The presented method was also applied on data other than cardiac optical mapping
Tremblay, Gérard. "Cartographie électro-optique de tension : application au test des circuits imprimés." Grenoble INPG, 1988. http://www.theses.fr/1988INPG0134.
Повний текст джерелаTremblay, Gérard. "Cartographie électro-optique de tension application au test de circuits imprimés /." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb376189527.
Повний текст джерелаTchomgo, Felenou Emmanuel. "Cartographie unifiée de la dynamique des solitons dans les guides d'onde à fibre optique." Phd thesis, Université de Bourgogne, 2013. http://tel.archives-ouvertes.fr/tel-00945451.
Повний текст джерелаYe, Fengchun. "Etude de l'organisation du génome des spiroplasmes : cartes physiques et génomiques de Spiroplasma citri et Spiroplasma melliferum et caractérisation de l'origine de réplication de Spiroplasma citri." Bordeaux 2, 1993. http://www.theses.fr/1993BOR28231.
Повний текст джерелаDubreuil, Nicolas. "Excitation par fibre optique et cartographie en champ proche des modes de galerie de microsphères de silice." Rennes 1, 1997. http://www.theses.fr/1997REN10161.
Повний текст джерелаWoillez, Julien. "Les noyaux actifs de galaxies en interférométrie optique à très longue base : projet OHANA." Paris 11, 2003. https://tel.archives-ouvertes.fr/tel-01084792.
Повний текст джерелаRecent progress in sensitivity achieved by the new generation of optical long baseline interferometers (VLTI & KECK) allows new fields of astronomy to benefit from very high angular resolution observations at near infrared wavelength. Extragalactic astronomy, through active galactic nuclei (AGN) observations, is one of those fields. As a preparation to coming active nuclei interferometric observations, I present a toolbox designed for the interpretation of the first data. I also present one of the two first observations of AGN: the Seyfert 2 NGC 1068 observed with MIDI, the newly commissioned 10 microns VLTI instrument. With the Seyfert 1 NGC 4151 by KECK, those two observations confirm the forecasted need of higher angular resolution to study the inner parts of the molecular torus found in active galactic nuclei. This would allow using an innovative tomographic technique I developed: interferometric reverberation. The 'OHANA project (Optical Hawaiian Array for Nanoradion Astronomy) aims at demonstrating the use of single mode fibers in J, H and K bands to coherently combine adaptive corrected telescopes, already present on top of Mauna Kea, into a very sensitive and resolving interferometer. I present the preparatory phase of the project where the coupling between adaptive optics and single mode fibers is studied on CFHT, GEMINI and KECK telescopes. Those tests allow me to confirm the sensitivity of the final instrument as well as to propose a diagnostic on the different adaptive optics systems. Then I present the new concept of the OHANA multicoaxial beam combiner. I present the ongoing developments of the interferometric demonstration phase, namely a gaussian beam delay line and 2x300m long single mode fibers, in ,J, H and K bands, used for the coherent transport
Gloppe, Arnaud. "Nano-optomécanique au coeur d'un faisceau laser focalisé : cartographie du champ de force optique et action en retour bidimensionnelle." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENY080/document.
Повний текст джерелаThis thesis is related to the field of nano-optomechanics and the use of nanomechanical resonators as ultrasensitive force sensor to study their interaction with light. A silicon carbide nanowire is positioned in a tightly focused laser beam. This enables, by measuring the transmitted intensity fluctuations, to observe with great dynamics and with a sensitivity close to the standard quantum limit the Brownian motion of the nanoresonator. The huge force sensitivity of the nanowires, due to their ultra low mass, permits to study the measurement backaction, which is induced by the force exerted on the nanowire by the focused laser beam. The exploitation of the slight degeneracy observed between the two transverse mechanical polarizations enables to realize a vectorial bidimensional cartography of the optical force field, with a probe of sub-wavelength diameter. This measurement highlights the non-conservative feature of the light-matter interaction, a symbolic signature being the existence of vorticity in the measured force field. The latter shows strong spatial variations, which modify deeply the nanowire dynamics. This measurement backaction is responsible of a strong coupling between the two mechanical polarizations of the nanowire fundamental mode. The bidimensional feature of the coupling and the force field non-conservative topology lead to a bifurcation and to a dynamical instability of the nanowire. This new optomechanical instability is observed with instantaneous optical forces, which follows instantaneously the intensity variations seen by the nanowire. In presence of absorption, a more general case of a force field partially delayed by the thermal time constants is studied, leading to a cooling, specific and tunable with the position, of the two mechanical polarizations. Then, the light-matter interaction between a laser and the nanowire and the great variety of optomechanical properties accessible with this approach are developed. These developments demonstrate the ability to observe and control optically nanomechanical resonators with a huge sensitivity, close to the attonewton, for ultrasensitive measurements of vectorial force fields
André, Gilles. "La détection et la cartographie des dommages et des marqueurs de catastrophes naturelles par imagerie spatiale optique et radar." Paris 7, 2002. http://www.theses.fr/2002PA070057.
Повний текст джерелаThe aim of our research is to study the potentialities and the limits of spatial imagery for the detection of damages after major natural hazard. In order to realize this work, we have studied several examples such as Izmit (1999) and Bhuj (2001) earthquakes, flood of the river Aude (1999), mud flow in Venezuela (1999), and the hurricane and flood in Madagascar and Mozambique (2000). In this work, we have studied and applied the more efficient image treatments for the damages detection, and we have also adapted and developed new methods such as the morphological anomalies recognition for the damages assessment and mapping. Our researches permit us to conclude on the potentialities and limits of each kind of special data. First, we have noted that radar imagery is unavailable for the detection of building damage levels after an earthquake. Only the optical data, at medium and high resolution permit to detect several levels of damage using a multitemporal analysis or morphological approach. Concerning the detection of damages after flood or mud flow, we have observed that results depend more on the geographic and meteorological situation than on the type of spatial data used. A compared study of different approaches on the same case has shown the great variabilty of the result depending on the methodology used. It doesn't seem to have a single and general method for the damages detection
Blanc, Frédéric. "Neuromyélite optique de Devic : troubles cognitifs et imagerie cérébrale par résonance magnétique." Strasbourg, 2010. https://publication-theses.unistra.fr/public/theses_doctorat/2010/BLANC_Frederic_2010.pdf.
Повний текст джерелаBackground : Neuromyelitis Optica (NMO) is an inflammatory disease of the central nervous system, characterized by myelitis and optic neuritis. Brain MRI is usually normal at the beginning of the disease. Moreover, brain inflammatory lesions are found in less 10% of cases. Cognitive testing has never been done before this study. Methods and Results: We compared 30 NMO patients to 30 multiple sclerosis (MS) patients and 30 healthy subjects, using the BCcogSEP. Cognitive impairment was found to be the same in NMO (57%) and MS (37%) patients: a frontal subcortical cognitive impairment. In MR-spectroscopy, in normal appearing white matter (WM), an grey matter (GM), we found no abnormalities. Global and focal brain volumes were analyzed in 32 NMO patients and 32 controls for WM and GM using SIENAx and VBM methods. We found a diminished global and focal WM, and coherent correlations between global and focal WM and cognitive dysfunctions. Conclusion: We have demonstrated for the first time the existence of cognitive impairment and a correlated atrophy in NMO, although it was considered as a restricted disease to the spinal cord and optic nerves. It is of importance now to better understand the origin of such dysfunction in analyzing the white matter and dysconnexions by DTI
Pang, Chengxin. "Contribution à l'étude de composants optiques intégrés passifs et actifs : couplage et cartographie optiques sub-longueur d'onde." Troyes, 2008. http://www.theses.fr/2008TROY0029.
Повний текст джерелаNowadays, integrated optical components al-low many optical functions including modulation, guiding and amplification. The component size has reduced gradually owing to the development of technologies such as SOI (Silicon on Insulator) and III-V technologies. In recent years, optical near-field microscopy (SNOM) has developed to become today a quantitative characterization technique as demonstrated in the laboratory on SOI structures with both amplitude and phase mapping (heterodyne SNOM). In this thesis, we address both the instrumentation development and the characterization of new samples. The first objective was to optimize the coupling stability of the heterodyne s-SNOM setup. This has allowed us to characterize single-mode nanostructured (porous) silicon waveguide for which coupling stability was found to be especially critical. More generally, addressing coupling stability led us to investigate the coupling of light in sub-wavelength waveguides. Efficient coupling has been demonstrated using adjustable Polymer-Tipped Optical Fiber (PTOF). Considering the complexity of the heterodyne SNOM, we studied a new simplified approach called Trans-SNOM where the tip-modulated light is detected though the transmission of the structure. Finally, prospective results have been obtained on the characterization of active components such as photonic crystal based micro-laser
Matteo, Lionel. "De l’image optique "multi-stéréo" à la topographie très haute résolution et la cartographie automatique des failles par apprentissage profond." Thesis, Université Côte d'Azur, 2020. http://www.theses.fr/2020COAZ4099.
Повний текст джерелаSeismogenic faults are the source of earthquakes. The study of their properties thus provides information on some of the properties of the large earthquakes they might produce. Faults are 3D features, forming complex networks generally including one master fault and myriads of secondary faults and fractures that intensely dissect the master fault embedding rocks. I aim in my thesis to develop approaches to help studying this intense secondary faulting/fracturing. To identify, map and measure the faults and fractures within dense fault networks, I have handled two challenges:1) Faults generally form steep topographic escarpments at the ground surface that enclose narrow, deep corridors or canyons, where topography, and hence fault traces, are difficult to measure using the available standard methods (such as stereo and tri-stereo of optical satellite images). To address this challenge, I have thus used multi-stéréo acquisitions with different configuration such as different roll and pitch angles, different date of acquisitions and different mode of acquisitions (mono and tri-stéréo). Our dataset amounting 37 Pléiades images in three different tectonic sites within Western USA (Valley of Fire, Nevada; Granite Dells, Arizona; Bishop Tuff, California) allow us to test different configuration of acquisitions to calculate the topography with three different approaches. Using the free open-source software Micmac (IGN ; Rupnik et al., 2017), I have calculated the topography in the form of Digital Surface Models (DSM): (i) with the combination of 2 to 17 Pleiades images, (ii) stacking and merging DSM built from individual stéréo or tri-stéréo acquisitions avoiding the use of multi-dates combinations, (iii) stacking and merging point clouds built from tri-stereo acquisitions following the multiview pipeline developped by Rupnik et al., 2018. We used the recent multiview stereo pipeling CARS (CNES/CMLA) developped by Michel et al., 2020 as a last approach (iv), combnining tri-stereo acquisitions. From the four different approaches, I have thus calculated more than 200 DSM and my results suggest that combining two tri-stéréo acquisitions or one stéréo and one tri-stéréo acquisitions with opposite roll angles leads to the most accurate DSM (with the most complete and precise topography surface).2) Commonly, faults are mapped manually in the field or from optical images and topographic data through the recognition of the specific curvilinear traces they form at the ground surface. However, manual mapping is time-consuming, which limits our capacity to produce complete representations and measurements of the fault networks. To overcome this problem, we have adopted a machine learning approach, namely a U-Net Convolutional Neural Network, to automate the identification and mapping of fractures and faults in optical images and topographic data. Intentionally, we trained the CNN with a moderate amount of manually created fracture and fault maps of low resolution and basic quality, extracted from one type of optical images (standard camera photographs of the ground surface). Based on the results of a number of performance tests, we select the best performing model, MRef, and demonstrate its capacity to predict fractures and faults accurately in image data of various types and resolutions (ground photographs, drone and satellite images and topographic data). The MRef predictions thus enable the statistical analysis of the fault networks. MRef exhibits good generalization capacities, making it a viable tool for fast and accurate extraction of fracture and fault networks from image and topographic data
Vedadi, A. "Etude et applications des amplificateurs paramétriques à fibre optique." Phd thesis, Université de Franche-Comté, 2008. http://tel.archives-ouvertes.fr/tel-00544865.
Повний текст джерелаCazals, Cécile. "Apport des données Sentinel-1 pour la cartographie des milieux humides." Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC1226/document.
Повний текст джерелаWetlands are threatened by climate change and the anthropization of natural environments. Satellite remote sensing is useful for environmental monitoring at large areas. However, when it comes to the study of hydrological dynamics, a significant temporal resolution is essential. The latter is difficult to reach with optical satellite imagery because of the cloud cover that masks the ground. Radar sensors are well suited to the characterization of hydrological dynamics thanks to the sensitivity of their measurements in the presence of water, whatever the vegetation in place. As a result, all Synthetic Aperture Radar (SAR) acquisitions are available, both day and night, regardless of cloud cover.Satellite radar remote sensing has gone through a revolution with the launch of the Sentinel-1A satellite, followed by its twins Sentinel-1B by the European Space Agency as part of the Copernicus program in 2014. These sensors acquire C-band data (λ = 5.6 cm) on a regular basis on Europe and their distribution is free for all users. Their temporal frequency initially of 12 days has decreased to 6 days from the end of 2016. This work aims at evaluating the potential of these data with high temporal resolution for the monitoring of water bodies and wetlands.The first part of this thesis focuses on water bodies mapping. We found confusion in the C-band radar response between water surfaces and that of some bare soils. We showed that the winter period is the least ambiguous and that the VH polarization is the most suitable for the mapping of water surfaces. Four methods of water detection have been compared. It appears that the use of unsupervised methods without a priori data is not conceivable and that the methods taking into account the spatial neighborhood give better results. Temporal filtering has been developed and has improved detection and avoided confusion between bare soil and permanent water surfaces. Water surfaces of more than 0.5 ha are more than 80% likely to be detected.A second part of this thesis is devoted to the monitoring of wet grasslands by radar remote sensing. The use of fully polarimetric data has shown that the VV/VH partial polarimetry configuration available on the Sentinel-1 sensor is able to characterize the prairial floods with or without vegetation. A method taking into account the temporal neighborhood allowed to process a series of 14 Sentinel-1 images to obtain 14 flood maps. The accuracy of floods maps at the intra-parcel scale has been estimated, it appears that if the precision is relatively good (80%), but the recall is rather low (40%). This method allow to establish intra- and inter-annual monitoring.This thesis has shown the potential of high temporal resolution radar images for the mapping of the water surfaces and for the monitoring of a wetland meadow
Pailhé, Régis. "Innovations relatives à l'évaluation du cartilage articulaire du condyle fémoral humain par une nouvelle modalité d'imagerie optique." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAS038/document.
Повний текст джерелаThe World Health Organization recommends as part of secondary prevention, the development of innovative imaging tools allowing early diagnosis and assessement of osteoarthritis (10). The objective of this thesis was to study full-field OCT imaging and determine its ability to evaluate intraoperative cartilage tissue.The first part of our work consisted in defining the most accurate qualitative and quantitative parameters to evaluate osteoarthritis-induced cartilage lesions according to the latest literature. This preliminary part seemed necessary to further develop peroperative cartilage evaluation strategies. Indeed, to our knowledge, no existing technique allowed cartilaginous tissue characterization. Among the quantitative parameters, the assessment of the cartilage surface on a micrometric scale appeared to be best correlated to the histological grades of osteoarthritis which are the gold standard. This review of the literature also revealed that the structural parameters, both biomechanical and biochemical, lacked of actual correlation with histological arthrosis stages, which limits their interest in fundamental research. Finally, we noticed the most appropriate imaging systems for cartilage characterization (MRI, SEM, etc.) were unusable peroperatively and were very rarely used in vivo.In the second part of our work, we evaluated the ability of full field optical coherence tomography (FFOCT) imaging to characterize cartilaginous tissue. We described the principle of full field OCT, its advantages and disadvantages compared to the other existing imaging techniques listed in our review of literature. We then displayed the results of the descriptive, qualitative and quantitative evaluations of osteoarthritic cartilage lesions by full field OCT. This experimental work is, to our knowledge, the first to develop a semi-automatic algorithm in order to assess cartilage degeneration on FFOCT images. This allowed us to identify six surface parameters strongly correlated with OARSI histological arthrosis.In the third part of the thesis, we tried to determine the clinical applicability of this work, exposed further perspectives and explained the research work that we lead. Indeed, although the surface parameters were strongly correlated with the osteoarthritis grades, it seems essential to develop and validate new quantitative parameters that can be combined with these first ones. We are currently working on two structural parameters: the cell density of the superficial layers of the cartilage and the analysis of the surface roughness of the cartilage. At the same time we are working on the development of a peroperative and minimally invasive imaging system for endoscopic surgery. The endoscopic probe FFOCT-NOCT developed with the LLTech company could in the future allow to characterize cartilage lesions with the parameters we validated during the ex-vivo experiments
Préa, Pascal. "Discrétisation des images : reconnaissance de formes et connexité discrète." Aix-Marseille 2, 1988. http://www.theses.fr/1988AIX22071.
Повний текст джерелаMariani, Robert. "Contribution à la lecture automatique de cartes." Rouen, 1997. http://www.theses.fr/1997ROUES090.
Повний текст джерелаHajj, Bassam. "Imagerie électro-optique Pockels aux échelles micro et nanométriques en physique et biophysique." Phd thesis, École normale supérieure de Cachan - ENS Cachan, 2010. http://tel.archives-ouvertes.fr/tel-00562142.
Повний текст джерелаPolge, Géraldine. "Etude de la faisabilité d'un système de cartographie de dose par stimulation optique et application à la radiothérapie à haut gradient de dose." Montpellier 2, 2001. http://www.theses.fr/2001MON20190.
Повний текст джерелаRakshit, Suvendu. "Interférométrie différentielle de la région à raies larges (BLR) des quasars : région centrale des quasars en combinant interférométrie optique et cartographie des échos lumineux." Thesis, Nice, 2015. http://www.theses.fr/2015NICE4049/document.
Повний текст джерелаThe broad line region (BLR) of Active Galactic Nuclei (AGN) contains the high velocity gas clouds transporting materialfrom the dust torus to the accretion disk around the central super massive black hole (SMBH). Unveiling BLR structure iscritical to understand the accretion mechanism driving the SMBH evolution and shaping the AGN inflows, outflows and jets.Reverberation Mapping (RM) constrains the BLR geometry, kinematic, mass and equivalent linear size with parameterdegeneracies and fudge factors depending from the source geometry. Optical Interferometry (OI) yields independentconstrains on BLR structure, mass and equivalent angular size. We developed a 3D geometrical model of BLRs to estimateboth RM and OI measures and to show that the combination of these two techniques will very substantially reduce theuncertainty of mass estimates and yield direct distance measurement from “quasar parallax”. We used this model and a MonteCarlo Markov Chain Bayesian parameter fit of simulated data to show that quasar parallax can measure distances withaccuracy better than 15%. We used it on actual data to interpret and explain our first OI observations of the BLR of thebright quasar 3C273 found to have a BLR of about 1750±35 light days (ld) much larger than predicted by RM (450±120 ld)and larger than the inner rim of the dust torus of about 800±270 ld, yielding a SMBH mass of 5±1 108 solar masses. Ourmodel and SNR computations show that the VLTI incoming instruments can observe about 60 BLRs covering more than 4decades of luminosity, enough to try a grand unification of BLRs models and a calibration of RM making QSOs majorcosmological probes
Stumm, Elena. "Location models for visual place recognition." Thesis, Toulouse 3, 2015. http://www.theses.fr/2015TOU30341/document.
Повний текст джерелаThis thesis deals with the task of appearance-based mapping and place recognition for mobile robots. More specifically, this work aims to identify how location models can be improved by exploring several existing and novel location representations in order to better exploit the available visual information. Appearance-based mapping and place recognition presents a number of challenges, including making reliable data-association decisions given repetitive and self-similar scenes (perceptual aliasing), variations in view-point and trajectory, appearance changes due to dynamic elements, lighting changes, and noisy measurements. As a result, choices about how to model and compare observations of locations is crucial to achieving practical results. This includes choices about the types of features extracted from imagery, how to define the extent of a location, and how to compare locations. Along with investigating existing location models, several novel methods are developed in this work. These are developed by incorporating information about the underlying structure of the scene through the use of covisibility graphs which capture approximate geometric relationships between local landmarks in the scene by noting which ones are observed together. Previously, the range of a location generally varied between either using discrete poses or loosely defined sequences of poses, facing problems related to perceptual aliasing and trajectory invariance respectively. Whereas by working with covisibility graphs, scenes are dynamically retrieved as clusters from the graph in a way which adapts to the environmental structure and given query. The probability of a query observation coming from a previously seen location is then obtained by applying a generative model such that the uniqueness of an observation is accounted for. Behaviour with respect to observation errors, mapping errors, perceptual aliasing, and parameter sensitivity are examined, motivating the use of a novel normalization scheme and observation likelihoods representations. The normalization method presented in this work is robust to redundant locations in the map (from missed loop-closures, for example), and results in place recognition which now has sub-linear complexity in the number of locations in the map. Beginning with bag-of-words representations of locations, location models are extended in order to include more discriminative structural information from the covisibility map. This results in various representations ranging between unstructured sets of features and full graphs of features, providing a tradeoff between complexity and recognition performance
Morin, David. "Estimation et suivi de la ressource en bois en France métropolitaine par valorisation des séries multi-temporelles à haute résolution spatiale d'images optiques (Sentinel-2) et radar (Sentinel-1, ALOS-PALSAR)." Thesis, Toulouse 3, 2020. http://www.theses.fr/2020TOU30079.
Повний текст джерелаThe estimation and monitoring of forest resources and carbon stocks are major issues for wood industry and public bodies. Forests play an important role in national and international plans for climate change mitigation (carbon storage, climate regulation, biodiversity, renewable energy). In temperate forests, monitoring is done at two different levels: on one hand, at local level, in small areas by the acquisition of many measures of forest structure parameters, and, on the other hand, by statistics at national level or in large administrative areas that are provided annually by public bodies. Temperate forests are highly anthropogenic (high spatial variability and fragmentation of stands), so there is currently a strong need for a more refined and regular maps of forest resources in these regions. Optical and radar satellite images provide information on the state of vegetation, tree structure and spatial organization of forests. In an exceptional context of free global availability, diversity, and quality of images with high spatial and temporal resolution, the aim of this PhD work is to set up the methodological bases for a generic and semi-automatic production of forest parameters mapping (biomass, diameter, height, etc.). We have assessed the potential of Sentinel-1 (C-band radar), Sentinel-2 (optical) time series, and ALOS2-PALSAR2 (radar, L-band) annual mosaics to estimate forest structure parameters. These satellite data are combined, using supervised learning algorithms and field measurements, to construct models for estimating aboveground biomass (AGB), mean tree diameter (DBH), height, basal area and tree density. These models can then be spatially applied over the entire territory by using satellite images, providing thus continuous information on the spatial resolution of the images used (10 to 20 meters). This approach has been conceived and tested on four study sites with different forest species and structural and environmental properties: the inner and the dune zone of the Landes forest (maritime pines), the Orléans forest (oak and Scots pines), and the forest of Saint-Gobain (oaks, hornbeams and beeches). The investigated issues are the satellite data to be used, the selection of explanatory variables, the choice of regression algorithms and their parameterization, the differentiation of forest types and the spatialization of forest parameter estimates. The primitives derived from satellite data provide information on the optical properties of soil and vegetation, the spatial organization of trees, the structure and volume of live wood of crowns and trunks. The use of nonlinear multivariate regression algorithms allows to obtain forest parameter estimates with relative error performance in the order of 15 to 35 % for the basal area (~ 2.8 to 5.9 m2/ha) depending on forest types, 5 to 20 % for height (~ 1.3 to 3 m), and 5 to 25 % for DBH (~ 1.5 to 8 cm). The results highlight the improvement by combining several types of satellite data (optical, multi-frequency radar and spatial texture indexes), as well as the importance of differentiating forest types for the construction of models. This high-resolution, regular mapping of the forest resource is very promising to help improving the monitoring and policy of territorial and national strategies for the timber sector, biodiversity and carbon storage
Gimenez, Rollin. "Exploitation de données optiques multimodales pour la cartographie des espèces végétales suivant leur sensibilité aux impacts anthropiques." Electronic Thesis or Diss., Toulouse, ISAE, 2023. http://www.theses.fr/2023ESAE0030.
Повний текст джерелаAnthropogenic impacts on vegetated soils are difficult to characterize using optical remote sensing devices. However, these impacts can lead to serious environmental consequences. Their indirect detection is made possible by the induced alterations to biocenosis and plant physiology, which result in optical property changes at plant and canopy levels. The objective of this thesis is to map plant species based on their sensitivity to anthropogenic impacts using multimodal optical remote sensing data. Various anthropogenic impacts associated with past industrial activities are considered (presence of hydrocarbons in the soil, polymetallic chemical contamination, soil reworking and compaction, etc.) in a complex plant context (heterogeneous distribution of multiple species from different strata). Spectral, temporal and/or morphological information is used to identify genera and species and characterise their health status to define and map their sensitivity to the various anthropogenic impacts. Hyperspectral airborne images, Sentinel-2 time series and digital elevation models are then used independently or combined. The proposed scientific approach consists of three stages. The first one involves mapping anthropogenic impacts at site level by combining optical remote sensing data with data supplied by the site operator (soil analyses, activity maps, etc.). The second stage seeks to develop a vegetation mapping method using optical remote sensing data suitable to complex contexts like industrial sites. Finally, the variations in biodiversity and functional response traits derived from airborne hyperspectral images and digital elevation models are analysed in relation to the impact map during the third stage. The species identified as invasive species, as well as those related to agricultural and forestry practices, and biodiversity measures provide information about biological impacts. Vegetation strata mapping and characterisation of tree height, linked to secondary succession, are used to detect physical impacts (soil reworking, excavations). Finally, the consequences of induced stress on the spectral signature of susceptible species allow the identification of chemical impacts. Specifically, in the study context, the spectral signatures of Quercus spp., Alnus glutinosa, and grass mixtures vary with soil acidity, while those of Platanus x hispanica and shrub mixtures exhibit differences due to other chemical impacts
Gonzalez, Sanpedro Maria del Carmen. "Optical and radar remote sensing applied to agricultural areas in Europe." Toulouse 3, 2008. http://www.theses.fr/2008TOU30228.
Повний текст джерелаEl aumento de la población mundial, así como la importancia social y económica que el sector agrícola tiene en muchas regiones del mundo, hace que sea muy importante desarrollar métodos que permitan hacer un seguimiento del estado de los cultivos, mejorar la gestión de los mismos, así como poder realizar una estimación temprana de la producción. La principal causa de incertidumbre en la producción de las cosechas es debida a las condiciones meteorológicas, por ejemplo, en las regiones áridas y semiáridas del mundo los períodos de sequía generan grandes pérdidas en la producción agrícola, la cuales se traducen en hambrunas. Así, la FAO, durante su cumbre de Junio 2008, insistió en la necesidad de aumentar a producción agrícola como una medida para reforzar la seguridad alimentaria y reducir la desnutrición en el mundo. La preocupación por aumentar la producción de cultivos, ha generado, durante las últimas décadas, importantes cambios en las técnicas agrícolas. Por ejemplo, se ha producido un uso generalizado de productos fitosanirios, de cultivos modificados genéticamente, así como un aumento de la agricultura intensiva. A su vez, la rotación de cultivos está cada vez más influenciada por el mercado, siendo los cambios en la distribución espacial de los cultivos muy frecuentes. Por lo tanto, para poder hacer estimaciones de la producción agrícola, es necesario producir eriódicamente mapas de cultivos, así como cartografiar su estado de desarrollo. La presente tesis doctoral tiene como objetivo desarrollar métodos basados en datos de teledetección, en la región del óptico y en la región del radar, que permitan realizar un seguimiento de los cultivos, así como una cartografía de los mismos. Los resultados de esta tesis pueden combinarse con otras técnicas, especialmente con los modelos de crecimiento de cultivo, para mejorar la predicción de las cosechas. Los métodos de teledetección para la clasificación y la cartografía de cultivos utilizando datos en la región del óptico están bien establecidos y pueden considerarse casi operacionales. La desventaja de estos estudios basados en datos ópticos es que no pueden aplicarse a regiones donde la cobertura nubosa es frecuente. En esos casos, la utilización de datos radar es más recomendable. Sin embargo, los métodos de clasificación utilizando datos radar no están tan bien establecidos y es necesario realizar más estudios científicos en este campo. Es por ello, que esta tesis se centra en la clasificación de cultivos mediante datos radar, concretamente datos aerotransportados AIRSAR y datos ASAR del satélite ENVISAT. El seguimiento de los cultivos mediante teledetección se basa en la estimación de parámetros biofísicos y su evolución en el tiempo. Estos parámetros son, entre otros, LAI (índice de área foliar), clorofila y biomasa. En esta tesis se han utilizado datos del satélite LANSAT-TM para la inversión de LAI, y datos ENVISAT-MERIS para la estimación de LAI y clorofila
Yauschew-Raguenes, Nathalie. "Dynamique saisonnière de la végétation forestière (arbres et sous-bois) dans le massif des Landes : application de la télédétection optique au suivi des hétérogénéités à l'échelle régionale." Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14702/document.
Повний текст джерелаThe aim of this thesis is to assess the potential of the remote sensing data to monitor the seasonal dynamic of the forest vegetation (understory and tree canopy). The study has been carried out on the maritime pine forest in the Southwest of France. It is based on a 7-year time-series of the 10-day vegetation index PVI composite derived from satellite and on in situ leaf area measurements (LAI) of understory and tree story.At first, the in situ observations have been analysed. It shows that the understory vegetation is the main driver of the seasonal dynamic of the whole forest LAI (understory+tree story). Then, these informations have been compared with the time-series of remote sensed PVI . It appears that the spring phenology of the PVI informs directly about the LAI understory one.Finally, these results have been used at the regional scale and a regional map of the lande types has been produced. This study opens some new prospects about integration and spatialisation of water and carbon balance of forest ecosystems at regional scale
Blin, St��phane. "R��alisation de lasers �� fibre �� contre-r��action r��partie pour l'��tude de l'injection optique : comparaison avec l'injection de lasers �� semi-conducteurs." Phd thesis, Universit�� Rennes 1, 2003. http://tel.archives-ouvertes.fr/tel-00078932.
Повний текст джерелаLe, Lay Hugo. "Caractérisation des échanges nappe-rivière par mesure distribuée de température par fibre optique : limites et applications aux faibles exfiltrations de nappe." Thesis, Tours, 2019. http://www.theses.fr/2019TOUR4025.
Повний текст джерелаGuignard, Celine. "Réalisation de sources impulsionnelles pour les télécommunications." Phd thesis, Université Rennes 1, 2005. http://tel.archives-ouvertes.fr/tel-00260197.
Повний текст джерелаMok, Jinmyoung. "Etude ultra-sensible en phase de nano-structures par interferométrie optique à balayage en champ proche." Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0086/document.
Повний текст джерелаIn this thesis, near-field scanning optical interferometry (NSOI), which combinesNSOM with interferometer, is proposed for the phase measurement. The shear-forcedetection scheme is applied for distance regulation. The hardware of the systemis constructed by combining various electronic devices, and the operating softwareis coded by LabVIEW. Unwanted background signal is removed by simple calculationbased on interference theory. By using this, the near-field optical measurementand the ultra-sensitive phase investigation of nano-materials are performed. 2D materialssuch as graphene and monolayer MoS2 are investigated. It is shown thatatomic-scale thickness can be resolved by the NSOI. Especially, the grain boundariesof graphene and the seed of MoS2 can be found by phase detection. In addition,direct laser writing (DLW) on silver-containing glass is observed by using NSOM,and NSOI. For the first time, the writing threshold is correlatively observed in thefluorescence imaging and the near-field phase image
Stumpf, André. "Landslide recognition and monitoring with remotely sensed data from passive optical sensors." Thesis, Strasbourg, 2013. http://www.theses.fr/2013STRAH025/document.
Повний текст джерелаLandslide inventory mapping and monitoring are indispensable for hazard assessment and disaster management. The enhanced availability of VHR satellites, UAVs and consumer grade digital cameras offers a great potential to support those tasks at regional and local scales, and to complement established techniques such as in situ instrumentation, radar, andlaser scanning. A lack of image processing tools for the efficient extraction process-relevant information from different types of optical imagery still complicates the exploitation of optical data and hinders the implementation of operational services. This doctoral thesis is dedicated to the development and application of image processing techniques for the mapping,characterization and monitoring of landslides with optical remote sensing data. A comprehensive review of innovative remote sensing techniques for landslide monitoring shows the potential and limitations of available techniques and guides the selection of the most appropriate combination of sensors – platforms – image analysis methods according to the observed process and end-user needs. For the efficient detection of landslides after major triggering events at the regional scale, a method for rapid mapping combining image segmentation, feature extraction, supervised learning is developed. For detailed landslide investigations at the local scale, this study elaborates image processing chains for detection of surface fissures in time-series of UAV images as geo-indicators of landslide activity, the measurement of horizontal surface displacements from VHR satellite images using stereo-photogrammetric and image correlation methods, and 3D measurements from terrestrial photographs based on multi-view open-source photogrammetry
Postadjian, Tristan. "Vers une occupation du sol France entière par imagerie satellite à très haute résolution." Thesis, Paris Est, 2020. http://www.theses.fr/2020PESC2018.
Повний текст джерелаFor political or environmental matters, land cover mapping has become more and more important since the beginning of the XXIst century. This mapping consists in, given a set of land cover classes, classifying ground-level objects according to these classes. Adressing very various applications, from a local scale (city-wise) to a more global scale (world-wide), several projects have been initiated so as to build land cover maps that would fit one of these applications. However, the current means to achieve this mapping are mainly manual, leading to high cost of production both in terms of man power and processing time. The task of building relevant land cover maps lies also in being able to monitor various phenomena in time, but acquiring data can be expansive for frequent updates or computation of maps at large scale. Yet, remote sensors have multiplied for the past two decades and the panel of such sensors is very wide and diverse in a spectral way and in terms of resolution. Among them, optical sensors boarded on Earth observation satellites acquire images in the visible and infrared spectrums, with high revisit time capabilities. SPOT 6 and 7 were launched in 2012 and 2014 respectively, and offer very high resolution images at 1.5m, in four bands. The French Mapping Agency computes each year a full France coverage from the SPOT data available through the THEIA data portal. Although this task has been widely studied in the past by the remote sensing community, by the means of supervised classifiers such as SVMs or random forests, none of the results have yet led to truly automated and satisfying maps that match existing specifications due to mislabelling errors that occur too often. In terms of methodology, the deep learning, and more specifically deep neural networks have proved to be far more efficient than other machine learning algorithms in various fields of research, from computer vision to natural language processing and system recommendation. These days, deep learning has become a part of everyday life, not only for academic research purposes, but also it society where it runs in the background of our smartphones for various tasks. Such ubiquity raises ethical issues: in particular, users’ browsing habits and behaviours are often monitored without them knowing to feed these algorithms. This heavy need for data is what allows deep learning to sketch more accurately a user behaviour, thus leading to more suitable commercial offers based on a history of purchases for instance.In our work, the French Mapping Agency topographic databases represent a real opportunity to massively train deep neural networks on the SPOT monoscopic very high resolution images, so as to produce land cover maps. The works reported in this dissertation are focused on this problematic of land cover mapping with deep neural networks on SPOT 6 and 7 data, with the additional constraint of tackling this task in a more general operational environment (large scale land cover mapping). This latter point ensures that the conducted experiments address occurring questions when classifying large geographic areas. For instance, a specific SPOT coverage is made of one image per territory, which means adjacent areas can have been acquired at different dates, leading to strong appearance discrepancies. Transfer learning is a tool that can help a lot in lots of scenarii so as to reduce both time computation and needs for training samples. Finally, in a context of the automatic update or re-computation of existing topographic database, the use of aerial images in deep neural networks is assessed in several tasks, with an emphasis on the training dataset conception from topographic database that can include some drawbacks
Sportouche, Hélène. "Extraction et reconstruction des bâtiments en milieu urbain à partir d'images satellitaires optiques et radar à haute résolution." Phd thesis, Paris, Télécom ParisTech, 2010. https://pastel.hal.science/pastel-00564891.
Повний текст джерелаThese works take place in the framework of building extraction and 3D building reconstruction in urban and semi-urban areas, from high-resolution optical and SAR satellite images. The main objective is to develop a complete semi-automatic processing chain, able to provide a simple and reliable reconstruction of parallelepipedic buildings on the scene, from a specific configuration of the input data, composed of an optical image and a SAR image, and from a digital terrain model. This restricted configuration, particularly delicate to deal with but likely to happen in operational conditions, has been until now studied only in a few works. Proposing a specific approach to manage such a scenario seems thus very interesting for a lot of applications in remote sensing. We aim to fully benefit from the data fusion context, by exploiting, in an appropriate way, the optical-SAR complementarities for the reconstruction of the scene, through the combination of planimetric and altimetric information. The proposed chain is decomposed into four steps: potential building detection in optical monoscopy; projection and registration of the potential optical footprints into SAR data; height estimation and building validation on the SAR image; qualification of the reconstructed buildings. The whole chain is applied on studied scenes issued from a couple of Quickbird and TerraSAR-X real data. The obtained results are qualitatively and quantitatively analyzed. A globally satisfying reconstruction of the buildings is achieved
Sportouche, Hélène. "Extraction et reconstruction des bâtiments en milieu urbain à partir d'images satellitaires optiques et radar à haute résolution." Phd thesis, Télécom ParisTech, 2010. http://pastel.archives-ouvertes.fr/pastel-00564891.
Повний текст джерелаMartinez, Marine. "Rôle des fibres de Purkinje dans le substrat arythmogénique et la mort subite." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0368/document.
Повний текст джерелаArrhythmias that lead to sudden death have previously been associated with a specializedcell type, the Purkinje fibers (PF). They form the cardiac conduction system, and have a majorrole in the electrical impulse and synchronous activation of the ventricles. However, they maybe involved in pro-arrhythmic phenomena causing the initiation or maintenance of ventricularfibrillation (VF) in structurally normal and a broad spectrum of cardiac diseases.Nevertheless, electrophysiological and structural characteristics of PF and mechanismsunderlying Purkinje-related arrhythmias are poorly understood. It is hypothesized thatthe Purkinje system plays an important role as a substrate for arrhythmias due to, in part,its impact on transmural repolarization heterogeneity.Here within are six studies describing electrophysiological and macro/micro structuralproperties of sheep and human left ventricles using a combination of conventional andinnovative methods.Results showed that PF, through junctions with the myocardium, locally modulatedthe action potential duration and played a role in the dispersion of repolarization. Therefore,revealing a potential role for PF in both, trigger and maintenance of VF.This work opens new therapeutic perspectives in preventive treatment of ventriculararrhythmia to fight against sudden cardiac death
Comtois, Philippe. "Stabilité de la réentrée anatomique dans le muscle cardiaque et annihilation par un protocole à deux stimulations : études de modélisation et aspects expérimentaux." Thèse, 2003. http://hdl.handle.net/1866/15113.
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