Dissertations / Theses on the topic 'Sans linker'
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Turelli, Lorenzo. "Étude de nouveaux motifs d'espaceurs dans la construction de conjugués anticorps-médicaments." Electronic Thesis or Diss., Strasbourg, 2023. http://www.theses.fr/2023STRAF063.
The class of Antibody Drug Conjugates (ADCs) represents one of the most fast-growing treatments in oncology therapeutics, enabling the use of highly cytotoxic compounds covalently linked to a monoclonal antibody (mAb) which can selectively get attached to an antigen expressed on the surface of the cancer cell, assuring the precision of this therapy. The linker motif, connecting the mAb to the drug, is key to dictate the modality of the drug’s release as for the pharmacokinetic and pharmacodynamic of the whole conjugate. However, the development of a novel linker is a costly and time-consuming process, in which the ideal motif has to assure both the stability in blood circulation and a fast kinetic in the release of the warhead inside the cancer cell. The work here described aims at addressing the limitations present in this field in two different ways: first by introducing a novel acid sensitive cleavable linker with excellent extracellular stability and selective cleavability in the cancer cell; secondly, embracing a linker-less approach, by introducing a new format of ADC, coined Self Drugged Antibody (SDA), in which the drug is built on the mAb through a Ugi multicomponent reaction
Berg, Joris van den. "Non-linear sand wave evolution." Enschede : University of Twente [Host], 2007. http://doc.utwente.nl/57884.
Vereecke, Jean. "Vers une conception optimale des réservoirs composites sans liner pour le stockage cryogénique." Electronic Thesis or Diss., Bordeaux, 2024. http://www.theses.fr/2024BORD0036.
In a context of mass and cost reduction for space launch vehicles, the design of linerless composite tanks constitutes a technological challenge. Their mass-to-performance ratio makes them a high potential material in the aerospace industry, but their permeability is a limiting factor. Indeed, tank pressurization and cryogenic propellant temperatures generate microscopic damage that can coalesce and form leak paths. Therefore, there is a strong relationship between damage to the composite laminate and its permeability.A strategy for developing a permeability prediction model is proposed. It is based on a dialogue between characterization of the elastic-damage behavior of the ply and simulation based on Finite Fracture Mechanics (FFM). The approach is validated experimentally and then, through homogenization methods, the model is transposed to a larger scale, adapted this time for use in an industrial context. This enables the damage state of each ply to be assessed as a function of thermomechanical loading. Finally, experimental comparison of the model enables us to identify the key parameters driving permeability and establish the validity range of predictions
Combes, Pascal. "Injection de signal et contrôle "sans capteurs" des moteurs électriques." Thesis, Paris, ENMP, 2015. http://www.theses.fr/2015ENMP0053/document.
This thesis proposes an in-depth study of some aspects of "sensorless" control algorithms for electrical machines. Over the past few years, thanks to the progress made in electronics, "sensorless" control laws became a standard expected from any variable speed drive for any electrical motor. However low-speed "sensorless" operation of electrical motors is inherently difficult, due to a theoretical limitation explained here by an observability study. Signal injection is a promising solution to circumvent this limitation, but its effects are not yet fully understood. In particular, experimental results are not explained by traditional linear sinusoidal models for electrical motors.Hence a new modeling approach for electrical motors is proposed here. It is much simpler than the usual ones and explains thoroughly why saturation can be modeled in the nonphysical dq frame. Signal injection effects are then explained using a multiple time-scale approach and, when put into the general context of nonlinear systems, it turns out to be a technique which allows to obtain more information without adding sensors. Thanks to this additional information, sensorless control of electrical motor becomes theoretically possible, even though the implementation remains challenging due to industrial constraints. Models for the Synchronous Reluctance Motor and the Induction Motor at no load are designed using the proposed approach and calibrated on experimental data but the procedure failed for the Induction Motor under load due to a lack of measurements combined to hysteresis effects. Besides, thanks to the similarities between electrical motors, underlined by the proposed modeling approach, we are able to generalize the proof of a "sensorless" control law designed for Synchronous Reluctance Motors to any kind of Permanent Magnet Synchronous Motor
Lewis, Corbin Robert. "Linear Dune Morphometrics in Titan’s Belet Sand Sea and a Comparison with the Namib Sand Sea." BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/7688.
Xie, Fangning. "Real-time SAXS and SANS studies of lamellar superlattices in linear and branched long alkanes." Thesis, University of Sheffield, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.500158.
Malenfant, Jean-Charles. "Influence de l’endommagement sur la perméabilité des matériaux composites : application à la conception d’une capacité cryogénique sans liner." Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14550/document.
This thesis deals with hybrid propulsion launcher systems studied by the CNES (Centre National d'Etudes Spatiales). The performance of the launcher implies its lightening and in this work, the use of a cryogenic composite linerless tank is evaluated. Three functional requirements must be satisfied: the compatibility between the composite material and the liquid oxygen (LOX), the tank gas-tightness and the strength under pressure.The LOX compatibility of composite materials implies high thermal conductivity of the composite, and consequently of the fiber reinforcement. This theoretical result is confirmed by experiments.The main scientific challenge concerns the damage influence on the composite permeability. Specific experimental devices allow determining the damage evolution (transverse cracking, delamination, opening crack) and the composite permeability. A predictive composite permeability model is applied to a composite wall under thermomechanical load: this model includes a ply-scale damage model, a predictive opening crack model and a model of flow through porous media. The relevance of the model is validated through the realization of a linerless prototype tank and the associated tests which correlate damage and permeability
Livingstone, I. "The dynamics of sand transport on a Namib linear dune." Thesis, University of Oxford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375978.
Laeuffer, Hortense. "Caractérisation et modélisation des réseaux de fissures pour la prédiction de la perméabilité des réservoirs composites stratifiés sans liner." Thesis, Paris, ENSAM, 2017. http://www.theses.fr/2017ENAM0044/document.
The design of liner-less composite pressure vessels for spatial launchers requires studying the relation between damage and permeability in laminates in order to offer solutions which fulfill strength and leak rate requirements. This study aims at providing a relevant description of damage growth and the resultant network at the meso-scale for leakage prediction. To do so, damage growth modelling is coupled with mechanical and permeability characterization. Two mains issues are addressed: crack network formation, by characterizing and modeling the growth and organization of cracks, and percolation and its effects on permeability, which is addressed by permeability measurement and leak path quantification. Several experimental methods based on optical microscopy and micro-tomography observations under tensile loading are proposed. These methods aim at evaluating the damage interaction and pattern of different plies in terms of cracking threshold, cracks length and relative location. Besides, two experimental setups are proposed to assess permeability evolution and percolation of cracks in pipes submitted to mono-axial or bi-axial loading. The results obtained for several carbon epoxy laminates manufactured by Automated Fibre Placement (AFP) are presented. At last, a multi-scale damage model based on energy release rates and finite fracture mechanics is introduced and key issues for developing a damage meso-model dedicated to the prediction of leak path density are established
Tay, Ying Ying. "Effect of dessication on the performance of bentonite-sand landfill liners." Thesis, University of Leeds, 2000. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.716355.
Rahil, Ahmad. "Gestion du Handover dans les réseaux hétérogènes mobiles et sans fil." Thesis, Dijon, 2015. http://www.theses.fr/2015DIJOS006/document.
Since 1990, networking and mobile technologies have made a phenomenal unprecedented progress. This progress has been experienced on multiple fronts in parallel; especially on the application level and the user's needs one. This rapid evolution of the technology imposed a need for the existence of heterogeneous environments where the coverage is ensured throughout the different available networks. The challenge with such architecture would be to provide the user with the ability to navigate through the different available networks in a transparent and seamless fashion. However, the navigation among different types of networks is commonly referred to as vertical Handover. The IEEE 802.21 standard offers a component that is called Media Independent Handover (MIH) which has a function that provides the capability of transmitting the state of the connection of the mobile nodes from the lower to upper layers. This layer would exist between layer 2 and layer 3 within the protocol architecture. The main role of MIH is to help the mobile node transfer without interrupt among different types of networks, but the logic of selection is left without implementation. In this context, we worked on the improvement of the Handover management by proposing a new architecture, called VHMC and based on MIH by offering new methods for selecting the destination network. The first solution is a new algorithm called Multiple Criteria Selection Algorithm (MCSA) based on multiple parameters of the quality of service. We used Network Simulator (NS2) for testing our approach and study the number of lost packets and lost time during Handover. The second solution is a new model for selecting the destination network based on fuzzy logic techniques. The distinctive characteristic of this model lies in the study of genuine Handover records taken from a Lebanese mobile operator called "Alfa". A third proposed solution for network selection is based on multiple linear regression theory
Genez, Thiago Augusto Lopes 1987. "Escalonamento de workflows para provedores de SaaS/PaaS considerando dois níveis de SLA." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/275686.
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação
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Resumo: Computação em nuvem oferece utilidades computacionais de acordo com a necessidade do usuário através do modelo "pago-pelo-uso". Usuários podem fazer o uso da nuvem através dos provedores de software (Software as a Service - SaaS), de plataforma (Plataform as a Service - PaaS) ou de infraestrutura (Infrastructure as a Service - IaaS). Computação em nuvem esta atualmente sendo muito utilizada. ...Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital
Abstract: Cloud computing offers utility computing according to the user's needs in a "pay-per-use" basis. Customers can make use of the cloud via Software as a Service (SaaS), Plataform as a Service (PaaS), or Infrastructure as a Service (IaaS) providers. ...Note: The complete abstract is available with the full electronic document
Mestrado
Ciência da Computação
Mestre em Ciência da Computação
Pattiaratchi, C. B. "Hydrography and sedimentology of a headland associated linear sandbank : Scarweather Sands, northern Bristol Channel." Thesis, Swansea University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.638426.
Arnold, Karl D. "Sand Sea Extents and Sediment Volumes on Titan from Dune Parameters." BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/4112.
Chandler, Clayton K. "Superimposed and Auxiliary Dunes of the Northern Namib Sand Sea: a Ground-Penetrating Radar Study." BYU ScholarsArchive, 2015. https://scholarsarchive.byu.edu/etd/5636.
Powell, Huw Joseph. "Water and sediment movement in the vicinity of linear sand banks : the Norfolk Banks, southern North Sea." Thesis, University of Southampton, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243121.
Laubé, Alexandre. "Agrégation de trafic pour réduire la consommation énergétique globale dans les réseaux sans fil multi-sauts." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS298/document.
Economic and ecologic incentives are now leading people to design networks with energetic considerations at early stages of development. Most of the works for multi-hop wireless networks tend to spread the traffic uniformly over the network to reduce the energy consumption of each node individually. However, considering that the traffic of a node doesn't impact significantly its energy consumption, this approach is not optimal regarding the global energy consumption of the network. Finding a way to turnoff as much node as possible seems then to be a better way. This PhD thesis focus on routing a set of flows over a multi-hop wireless network while minimizing the number of used nodes. This is done by using a distributed metric that allows the shortest path routing algorithms to perform flow aggregation. Using integer linear programming and simulations, we proposed an efficient solution to aggregate flows to significantly reduce the number of nodes used in the network. It allows, then, to improve algorithms that reduce the energy consumption of networks by increasing the number of nodes that can be turned off
Ndoye, El Hadji Malick. "Réseaux de capteurs sans fil linéaires : impact de la connectivité et des interférences sur une méthode d'accès basée sur des jetons circulants." Thesis, Clermont-Ferrand 2, 2015. http://www.theses.fr/2015CLF22661/document.
In this thesis, we propose a MAC protocol that takes into account the specific characteristics of LSNs. This MAC protocol is based on tokens circulating that give the right to nodes to access to the transmission channel. We evaluate from this protocol the impact of interference and connectivity in the LSN. This evaluation allows us to propose clustering techniques in a LSN. We assume first a clustering based on a logical exploitation of the vicinity of the sensor nodes. In this case, we assume that a deterministic propagation model that does not take into account the complexity of the environment. Next, we consider a clustering technique wherein the propagation model takes into account the fluctuations that make complex the medium
CARAFFA, BERNARD Daniela. "Equations aux dérivées partielles elliptiques du quatrième ordre avec exposants critiques de Sobolev sur les variétés riemanniennes avec et sans bord." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2003. http://tel.archives-ouvertes.fr/tel-00003179.
Sarr, Moussa Dethié. "Spécification d’un mécanisme de construction automatique de topologies et d'adressage permettant la gestion dynamique des réseaux de capteurs sans fil linéaires." Thesis, Université Clermont Auvergne (2017-2020), 2018. http://www.theses.fr/2018CLFAC001/document.
Linear wireless sensor network (LWSN) are a sub-case of wireless sensor network where sensor nodes are roughly deployed through multiple long lines with branches. LWSN are used to monitor infrastructures such as roads, pipelines, and naturals entities such as rivers.Classical solutions of topology construction and addressing are inefficient on LWSN . Indeed, with initials networks parameters such as the maximum number of children per node (Cm), the maximum number of children routers per node (Rm), and the maximum tree depth, a solution like ZigBee causes a waste of available address space of network nodes and limit the depth of the addressable tree to 15 hops. Other solutions proposed for LWSN use a cluster-tree organisation and are based on initial network parameters such as the maximum number of children clusters per cluster. In addition, these solutions require a lot of manual intervention on different sensor nodes and do not allow adaptation for a network extension (addition of a set of new sensor nodes). In this thesis, we propose protocols to allow the automatic construction of topologies, the addressing and the data routing for linear wireless sensor networks. Our contribution also provides mechanisms for dynamic management of LWSN (addition of new nodes, addresses reallocation, and data routing to multiple sink nodes). Our different protocols are evaluated using Castalia/Omnet++ simulator. Results of our simulations show that our protocols allow a construction of connected LWSN with very few orphan nodes and without depth limitations. We also show that our contribution allows to add many new nodes on different LWSN, and adapts to the deployment of multiple sinks to improve the ratio and the latency of data delivery packets
Li, Ling. "Thermally and Chemically Induced Changes in Interface Shear Behavior of Landfill Liners." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32995.
Hammami, Maroua. "Comportement mécanique et vibratoire des composites stratifiés sains et endommagés par délaminage." Thesis, Le Mans, 2016. http://www.theses.fr/2016LEMA1022/document.
The aim of this work is to investigate the effects of delamination lengths on the static, fatigue, linear and nonlinear vibration behaviour of composite materials. An analytical model is first presented using laminated beams theory of bending behavior. A study was conducted in static and cyclic fatigue loading with various debonding lengths. Flexural modulus in static tests was determined using the composite plate theory. The effects of delamination lengths on the stiffness, hysteresis loops and damping were studied for various numbers of cycles during fatigue tests. Then, modeling of the damping of a composite with delaminaton was established considering finite element analysis which evaluated the different energies dissipated in the material directions. The effects of delamination variable lengths on natural frequencies and damping were studied numerically and compared with experimental results. Finally, the nonlinear vibration method was used to characterize the behaviour of composite beams with delamination. The nonlinear parameters corresponding to the elastic modulus and damping were determined for each frequency mode and each debonding length. The results showed that nonlinear parameters were much more sensitive to damage than linear parameters
Gerosa, Leonardo Emerick. "Remoção e degradação de alquilbenzeno linear sulfonado de efluente urbano em reator de leito fluidificado em escala piloto." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-16042018-103139/.
In this work, it was studied the removal and degradation of linear alkylbenzene sulfonates (LAS) in a sanitary sewage effluent from the Monjolinho Sewage Treatment Station of the city of São Carlos-SP. For such, it was used a pilot scale anaerobic fluidized bed reactor (AFBR), filled with sand as support material. The reactor was operated with 18 hours of TDH and mesophilic temperature. Physicochemical and chromatographic analyzes were performed both in the characterization of the sewage inflow and in the monitoring of the reactor. The variation in concentration of COD and LAS were of 653,50 ± 169,30 mg L-1, and 6,189 ± 3,25 mg L-1, respectively. Regarding potentially toxic metals, cadmium, lead, manganese, nickel and zinc were observed, traces of Iron were also found. Regarding recalcitrant compounds was observed in sanitary sewage, butyl benzenesulfonamide, hexadecanoic acid, limonene, terpinene, phenol, phenylethyl alcohol, indolizine, caffeine and isobutyl octadecyl phthalate were observed. The AFBR was operated in a continuous stream during 220 days. During this period the COD concentration was 503.84 ± 187.06 mg L-1 and 210.53 ± 78.37 mg L-1, afluente and effluent, respectively, with a removal efficiency of 56 ± 14%. In regard to the surfactant LAS, was observed 7.77 ± 3.06 mg L-1 and 5.67 ± 2.84 mg L-1 a ffluent and effluent respectively, being the efficiency of removal of 28 ± 27%. When the mass balance was perform, it was possible to verify that only 0.1% of this LAS removal was by adsorption. The effluent pH remained stable, close to neutrality 7.40 ± 0.32, the total effluent alkalinity was 233.40 ± 40.75 mgCaCO3 L-1 and volatile organic acids 57.64 ± 48.08 mg L-1.
Olsen, Peter A. "Shear Modulus Degradation of Liquefying Sand: Quantification and Modeling." BYU ScholarsArchive, 2007. https://scholarsarchive.byu.edu/etd/1214.
Lopes, Telma Sofia Risso. "Advantages and drawbacks of a linear focusing system with low melting point molten salts." Master's thesis, Universidade de Évora, 2019. http://hdl.handle.net/10174/31058.
McMahon, Brendan. "Deformation mechanisms beneath shallow foundations." Thesis, University of Cambridge, 2013. https://www.repository.cam.ac.uk/handle/1810/244367.
Manesco, Clara. "Etude photonique et nano-mécanique pour le suivi sans marquage de la cicatrice fibrotique dans les lésions de la moelle épinière chez la souris." Electronic Thesis or Diss., Université de Montpellier (2022-....), 2023. http://www.theses.fr/2023UMONS072.
Spinal cord injuries (SCI) are part of the most impactful pathologies in the central nervous system (CNS). They can induce dramatic physical and psycho-social effects for the patients, associated with a consequent impact on the health care system. When an injury occurs, it induces a cascade of events disturbing the surrounding structures and cell populations, and includes the formation of a glial scar. This scar is composed of various cell populations such as activated microglial and astrocytes. Fibroblasts are producing collagen with the support of reactive astrocytes and are involved in the fibrotic process. The glial scar is a dense chemical and physical barrier with dual effects on the recovery. No curative treatment is currently available. However, promising pharmaceutical approaches have been developed through the transient depletion of microglia using a GW2580 treatment, an inhibitor of CSF1R receptor that specifically regulates the proliferative part of microglial cells.The exploration of collagen in the glial scar formation has raised poor attention comparing to the interest in microglia and astrocytes roles. Fibrillar collagen as collagen I is well known in common wound healing processes occurring in the rest of the body, and is defined by a supramolecular organization in cross-striated fibril shaped into a cylindrical structure and eventually associated into fibers. This assembly leads to unique optical properties that can be directly monitored by non-linear optical measurements (NLO), such as Second Harmonic Generation (SHG), without special sample preparation and without any exogenous labeling. As SHG is a coherent signal that depends on the polarization of the incident laser by performing Polarization-resolved SHG (P-SHG) collagen fibers arrangement at a supramolecular level can be assessed related to the fibrils nature (related to their symmetry profiles).The global approach proposed in our work was to exploit the potential of NLO optics in detecting and characterizing fibrillar collagen in SCI (using Multiphoton microscopy to visualize simultaneously 2-photon excited fluorescence and SHG signals) in a mouse model and to correlate the structural information to the biomechanical behavior of the tissue via micro/nano-indentation force measurements with Atomic Force Microscopy (AFM). Collagen fibers exhibited by their SHG signal were characterized with two methods: CurveAlign software dedicated to collagen fibers analysis in biological samples and a home-build Fingerprint algorithm establishing an analysis pipeline more adapted to our study. We eventually generated a skeleton map of the fibers to extract relevant metrics such as the fibers’ density, tortuosity and orientation at local level (calculating the circular variance of the local orientation) and at global level (calculating the statistical entropy). Our multimodal label-free imaging approach was thus dedicated to reveal and monitor lesion biomarkers from the fibrotic structure and the elasticity of injured spinal cord tissues after various time-points post-injury and to investigate the potential effect of a pharmacological treatment with GW2580 at 6 weeks post injury. The SHG signal exhibited by fibrillar collagen enabled to specifically monitor it as a biomarker of the lesion. An increase in collagen fibers density and the formation of more tortuous fibers overtime from 1 week to 6 weeks post-injury was observed. P-SHG measurements revealed both fibrils symmetry types (cylindrical and trigonal) at all the time-points post injury. Nano-mechanical investigations revealed a noticeable hardening of the injured area from 1week post injury, correlated with collagen fibers’ formation.These observations indicate the concomitance of important structural and mechanical modifications during the fibrotic scar evolution following a spinal cord injury in mice
Beciu, Andreea-Livia. "Commande robuste à haute performance sans capteur de position d'alterno-démarreurs à grande vitesse avec un fort couple à l'arrêt pour les avions plus électriques." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLC078.
The aircraft manufacturers express the need to develop a more "electric" aircraft. This brings forward new requirements for the electric drive systems in terms of increasing the available on-board power and resource sharing in order to optimize the overall mass and cost. Among the ongoing studies on the evolution of motor drives, a particular interest is given to the development of multi-level brushless synchronous starter/generators (BSSG). These drives are likely to provide the high torque required to start-up the reactors to which they are associated. For this purpose, the knowledge, at any time, of the rotor position is essential. However, adding a dedicated sensor impacts on the design of the machine, increasing volume, cabling needs and cost. For this purpose, investigating on “sensorless” control laws will permit to avoid using such a sensor and to simplify the design of the Starter/Generators.Using a fine modelling of the machine, this work studies the conditions of feasibility for sensorless control and analyzes several techniques for this purpose. A new method of estimation of the shaft-position, particular to the BSSG architecture is proposed and then illustrated with experimental results. This technique is based on the processing of the existing harmonic components naturally in the stator of the machine and allows the estimation of the position at standstill and the very low speed. To extend the estimation to the whole speed range, a study of position estimation using a state observer using the complete model of the machine considering the knowledge of the existing (or injected) harmonic components in the stator currents is proposed. This observer can be applied to the brushless synchronous starter/generator but also on generic synchronous machines. In this study, its performance is illustrated on a permanent magnet synchronous machine
Song, Ning. "The Framing of China's Bird Flu Epidemic by U.S. Newspapers Influencial in China: How the New York Times and The Washington Post Linked the Image of the Nation to the Handling of the Disease." Digital Archive @ GSU, 2007. http://digitalarchive.gsu.edu/communication_theses/27.
Andary, Sébastien. "Contributions à la commande des systèmes mécaniques sous-actionnés : du concept à l'implémentation temps réel." Thesis, Montpellier 2, 2014. http://www.theses.fr/2014MON20110/document.
This thesis is focused on non linear control of underactuated mechanical systems, thoses systems with less actuators than degrees of freedom. The internal dynamics of such system is often unstable making them particulary difficult to control. Thus specific care must be taken when designing controlers for such systems. The main contribution of this thesis is the design of two new control schemes for stable limit cycles generation on all coordinates of underactuated mechanical systems. First control approach is based on partial feedback linearization and reference trajectories optimization. Second approach is based on recent work on model free control,a control scheme which doesn't require prior mathematicalmodel of the controlled system dynamics. The proposed approaches are applied to an inertiawheel inverted pendulumtestbed. Several experimental scenarios are proposed, both in numerical simulation and in realtime implementation. Obtained results demonstrate the ability of both controllers to stabilize the system around stable limit cycles and to reject external disturbances
Oliveira, Lorena Lima de. "Remoção de alquilbenzeno linear sulfonado (LAS) e caracterização microbiana em reator anaeróbio de leito fluidificado." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-27042010-132127/.
This work presents the anaerobic degradation of linear alkylbenzene sulphonate (LAS), a surfactant widely used in the production of detergents and present in domestic and industrial wastewaters. It was used an anaerobic fluidized bed reactor in bench scale (1,2L) filled with support material for biomass immobilization. Four different supports were previously tested in small scale fluidized bed reactors (350 ml): activated charcoal (R1), expanded clay (R2), glass beads (R3) and sand (R4). All reactors were inoculated with sludge from a UASB reactor treating swine wastewater and were fed with a synthetic substrate supplemented with LAS. The reactors were kept at 30ºC and operated with a hydraulic retention time (HRT) of 18 h. It was possible to note that the four tested reactors were able to remove organic matter (higher than 84%) and LAS (higher than 81%), respectively, to initial mean value of 550 mg/L and 16.5 mg/L. However, activated charcoal and expanded clay both produced shearing during reactor operation. Thus, sand was the chosen material to fill the bench scale reacto because of good results of LAS removal (99%) and smaller cost and affordability compared to glass beads. After 270 days of operation, with crescent LAS concentrations and average of 32,3 mg/L, it was found that the bench scale reactor was able to remove LAS in 93%. All supports adsorb a few LAS (maximun of 0.43 mgLAS/gclay). This value does not interfere in biologic removal process. Microscopic tests done during the reactor´s operation presented microorganisms with morphologies similar to spirochetes, bacillus, filamentous, cocci and others. 16S rRNA gene sequencing and phylogenetic analysis of samples from the bench scale reactor and smaller reactor filled with glass beads (R3) and sand (R4) revealed that these reactors gave rise to broad microbial diversity, with microorganisms belonging to the phyla Bacteroidetes, Proteobacteria, Verrucomicrobia and Firmicutes, and others.
El, Assami Yassine. "Homogénéisation en viscoélasticité linéaire non-vieillissante par la méthode de l'inclusion équivalente : application aux matériaux cimentaires." Thesis, Paris Est, 2015. http://www.theses.fr/2015PEST1051/document.
The prediction of long-term behaviour of cementitious materials is a major concern which contributs to the study of the durability of prestressed structures. This work focuses on the use of the equivalent inclusion method, simplified multi-scale homogenization approach, for the prediction of creep in these materials. Creep is modelled by the non-ageing linear viscoelasticity. The equivalent inclusion method overcomes certain difficulties and limitations posed by conventional approaches. For cementitious materials (highly heterogeneous), conventional multi-scale approaches are, either digitally heavy and complex to implement, or not sufficiently detailed to take into account the specificities of a microstructure. The equivalent inclusion method presents a middle way and allows the calculation of simplified matrix-inclusion type microstructures and to provide estimates or bounds on the homogenized behaviour.Under its variational form, the equivalent inclusion method has, up to now, been implemented only for spherical inclusions. This work proposes to extend this method to ellipsoidal inclusions whose variation of slenderness allows the modelling of new aspheric elements such as cracks, fibers and portlandite crystals. Such enrichment of the geometry has an impact on the computation time, that is amplified in the context of creep. The second aspect of the work then applies to the extension of the equivalent inclusion method to the non-ageing linear viscoelasticity by means of the Laplace-Carson transform. An effective methodology (both from the viewpoint of precision and calculation time) is finally proposed to perform the numerical inversion of this transform
Carlini, Elaine Carina. "Estudo sobre a expansão térmica linear das areias de fundição e a sua influência sobre as propriedades a quente dos machos." Universidade do Estado de Santa Catarina, 2011. http://tede.udesc.br/handle/handle/1794.
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
This paper presents a study on the linear thermal expansion of foundry sands used as aggregates in foundry cores with resin phenolic-urethane/Cold Box. The work examines the correlation between thermal expansion of the sand and hot deformation tendency of the core during the casting process. The hot deformation tendency has important technological significance, because it affects the dimensional quality of the casting. It was tested three silica sands, one chromite sand, two types of based aluminum silicates sands and two types of blended minerals. The sands were characterized for particle size distribution, loss on ignition, AFS clay content, density, permeability, pH, acid demand, specific surface area, coefficient of angularity, chemical analysis, XRD, shape and surface of the grains and linear thermal expansion. The dilatometer test was done with loose unbonded sands. The sand was placed into an alumina sample holder and inserted into the dilatometer. The hot deformation tendency of the core was performed with two tests: first, using an experimental iron casting and second a hot distortion laboratory test, in which the test specimen was subjected to heating by a flame. It was verified that the hot deformation tendency is directly correlated to the thermal expansion of the sand. The higher the thermal expansion of the sand used to make cores the more susceptible it is to hot deformation.
O presente trabalho apresenta um estudo sobre a influência da expansão térmica linear das areias de fundição utilizadas para a confecção de machos com resina fenólicauretânica/ Cold Box sobre a tendência à deformação a quente dos machos durante o processo de fundição das peças. A tendência à deformação a quente dos machos tem grande importância tecnológica, porque isto afeta diretamente a qualidade dimensional das peças fundidas. Foram ensaiadas três areias de sílica, uma areia de cromita, duas areias à base de silicato de alumínio, dois compostos de minerais. As areias foram caracterizadas quanto à distribuição granulométrica, perda ao fogo, teor de argila AFS, densidades solta e relativa, permeabilidade, pH, demanda ácida, superfície específica, coeficiente de angularidade, análise química, difratometria de raios-X, formato e superfície dos grãos e expansão térmica linear. O ensaio de dilatometria das areias foi realizado em corpos de provas não ligados com aglomerantes, ou seja, a areia foi acondicionada em um porta-amostra de alumina e este foi inserido no dilatômetro. Foram executados dois ensaios de tendência à deformação a quente dos machos: o ensaio de corpo de prova fundido e o ensaio de distorção a quente em laboratório, onde o corpo de prova (macho) é submetido a um aquecimento por chama. Verificou-se que a tendência à deformação a quente dos machos tem correlação direta com a expansão térmica da areia. Quanto maior a expansão térmica da areia utilizada para a confecção do macho mais suscetível ele estará à deformação a quente.
Fouquet, Yoann. "Optimization methods for network design under variable link capacities." Thesis, Compiègne, 2015. http://www.theses.fr/2015COMP2233/document.
This thesis summaries the work we have done in optimization of resilient communication networks. More specifically, the main goal is to propose appropriated recovery mechanisms for managing the demand traffic in a network under partial failures, i.e. when some part of the network (one or some links and/or nodes) is operational with reduced capacity. The main criterion in deciding the efficiency of the proposed recovery scheme is the dimensioning cost of the network while keeping the management cost at reasonable levels. Our main contribution is the design of two restoration strategies named Flow Thinning and Elastic Flow Rerouting. This document is organized in three main parts. In the first part, we present the problematic of the thesis. It includes an introduction on the protection and rerouting state-of-art strategies, together with their mathematical models and resolution methods. The second part presents in depth the first protection strategy named Flow Thinning. This strategy manages partial failures by decreasing appropriately the bandwidth on some flows routed through one of perturbed links. This implies overdimensionning of the network in the nominal state to ensure demand traffic in all failure states. The third and last part deals with the second rerouting strategy called Elastic Flow Rerouting. This strategy is a bit more complex than the first one because, in a failure state, we need to distinguish demands which are disturbed and the one which are not. If a demand is disturbed, it can increase the traffic on some of its paths. If it is not disturbed, it can release bandwidth on paths at the condition it remains non-disturbed. All this allows for further reducing the dimensioning cost but at a higher cost in terms of recovery process management. Note that the dimensioning problems for each strategy are shown to be NP-hard in their general form. The work of the thesis has been published in: three journal articles (Fouquet et al. (2015b), Pióro et al. (2015), Shinko et al. (2015)), two invited articles (Fouquet and Nace (2015), Fouquet et al. (2014c)) and height articles in international conferences (Fouquet et al. (2015a; 2014d;a;b;e), Pióro et al. (2013b;a), Shinko et al. (2013)). Note that Pióro et al. (2013b) has been rewarded by a "Best Paper Award" from the RNDM conference. To conclude, note that this thesis was realized in the Heudiasyc laboratory, from the Université de Technologie de Compiègne (UTC). It was financed by the French Ministry of Higher Education and Research1 with the support of the Labex MS2T2 of the UTC
Motteran, Fabricio. "Caracterização da comunidade microbiana de reator anaeróbio de leito fluidificado envolvida na degradação de surfactante não iônico álcool etoxilado de cadeia não ramificada (GENAPOL)." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-14032014-152720/.
The aim of this study was to evaluate the removal of nonionic alcohol ethoxylate non-branched (AE) in anaerobic fluidized bed reactor filled with sand as support material, on a bench scale (1.2 L) with 18 hours of TDH, recirculation and continuous flow. The reactor was inoculated with sludge from a UASB reactor used in the treatment of swine manure and fed with synthetic substrate plus nonionic GENAPOL® C-100 (Sigma-Aldrich®) as a source of AE. Monitoring analysis of the nonionic surfactant AE concentration and organic matter, as well as the physicochemical parameters were performed to observe and quantify the reactor stability, in the removal and degradation of the surfactant. The reactor operation was divided into five phases: inoculation (535±121 mg/L of COD), biomass adaptation (600±70 mg/L of COD), Phase I (4,7 mg/L of AE and 623±65 mg/L of COD), Phase II (22,5 mg/L of AE and 735±87 mg/L of COD), Phase III (51,4 mg/L of AE and 697±68 mg/L of COD), Phase IV (107,4 mg/L of AE and 845±87 mg/L of COD) and Phase V (97,9 mg/L of AE and 882±126 mg/L of COD). Application of the techniques PCR/DGGE and pyrosequencing of the 16S rRNA region were performed to observe the microbial diversity in the operational phases IV and V. The average removal efficiency of organic matter and AE was 88% and 99%, respectively, during the reactor operation. The populations similarity of the Archaea and Bacteria Domains were 74% and 59%, respectively, for samples from Phase IV (with sucrose) and Phase V (without sucrose). Sucrose did not alter the physical-chemical behavior of the fluidized bed reactor, but this co-substrate influenced both in the volatile fatty acids production, as in the diversity of microorganisms involved in the AE degradation. Through the pyrosequencing analysis of samples from Phases IV and V of the reactor (support material and phase separator), 83 genera were identified of which 18 were related to the nonionic surfactant degradation, as well as its byproducts. Highest relative abundance values were obtained for the following genera: Sporomusa, Geobacter, Desulfobulbus, Synergistes, Sedimentibacter, Holophaga, Serpens and Azonexus. A high phylogenetic diversity and similarity to sequences of bacteria related to the degradation of nonionic AE surfactant were observed.
Tinani, Suraj P. "Techniques to Analyze Underdeposit Corrosion." Case Western Reserve University School of Graduate Studies / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=case1272643724.
Nyström, Erika. "Typografisk makt : Hur värderas typografi?" Thesis, Konstfack, Grafisk Design & Illustration, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:konstfack:diva-6877.
Typography is everywhere. It speaks to us and makes us understand the world. Why do we regard some typefaces as serious/professional and some as less serious? My project is an investigation of the relation between the values of society and typography.
Younes, Mohamad. "Techniques de pré-distorsion numérique pour l'optimisation des réseaux d'accès optiques." Thesis, Brest, 2019. http://www.theses.fr/2019BRES0044.
The increase in bandwidth and access flexibility are major challenges for future telecommunication networks. In this context, optical fiber is an essential transmission medium that nowadays allows symmetrical data rates in the Gb/s range. The coherent detection and use of multi-carrier modulation formats has recently had a profound impact in the field of optical communications. One of the most notable implementations is the coherent optical OFDM (CO-OFDM). However, OFDM has a significant peak factor due to the various non-linearities of the channel, which is a downside limiting its performance.The objective of this thesis was to optimize the performance of the CO-OFDM transmission system by exploring the pre-distortion of digital baseband signals for linearization of the transmitter, and mainly of the semiconductor optical amplifier (SOA). Various pre-distortion algorithms were evaluated and have shown their impact on the trade-off between performance and low parametric complexity.As the pre-distortion system is non-adaptive, its robustness with respect to variations in transmitter characteristics and amplifier operating point was evaluated. The optimization of a particular pre-distortion structure has also been proposed
Duque, Alexis. "Bidirectional visible light communications for the internet of things." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEI072/document.
With the exponential growth of the Internet of Things, people now expect every household appliance to be smart and connected. At the same time, smartphones have become ubiquitous in our daily life. Their continuous performance improvement and their compatibility with a broad range of radio protocols as WiFi, Bluetooth Low Energy (BLE) or NFC make them the most convenient way to interact with these smart objects. However, providing wireless connectivity with BLE or NFC means adding an extra chipset and an antenna, increasing the object size and price. Previous works already have demonstrated the possibility of receiving information through visible light using an unmodified smartphone thanks to its camera. Also, LED-to-LED communication for smart devices like toys has been shown previously. However, past efforts in LED to camera communication for IoT device communication have been limited. In this work, we design LightIoT, a bidirectional visible-light communication (VLC) system between a low-cost, low-power colored LED that is part of an IoT device and an off-the-shelf smartphone. The IoT device is thus able to send and receive information through its LED, while the smartphone uses its camera to receive data and its flashlight to send information. We implement and experimentally evaluate a LED-to-camera VLC system, designed specifically for small LEDs. The proposed solution exploits the rolling shutter effect of unmodified smartphone cameras and an original decoding algorithm, achieving a throughput of nearly 2 kb/s. Based on the insight gained from an extensive experimental study, we model, for the first time in the literature, the LED-to-camera communication channel. We propose a Markov-modulated Bernoulli process model, which allows us to easily study the performance of different message retransmission strategies. We further exploit this model to implement a simulator for LED-to-Camera communications performance evaluation. In order to achieve bi-directional communications, we evaluate flashlight-to-LED communications using non-rooted smartphones and small LEDs. With these constraints, our implementation achieves a throughput of 30 bits/second. While limited, this is enough for a feed-back channel coming to support the required redundancy mechanisms. Some of these redundancy mechanisms are based on random linear coding, never tested previously in VLC. Therefore, we design and implement, for the first time in the literature, a pseudo random linear coding scheme especially fitted for line-of-sight LED-to-camera conditions. Experimental evaluation highlights that this type of approach increases the goodput up to twice compared to classical retransmission strategies. Finally, we compare the energy consumption of LightIoT with the one of a BLE module with similar activity. Our results show that using the LED for communication purposes reduces the energy consumption under a normal usage behavior
Ahmed, Yousif Elhadi Elsideeg. "Modeling, Scheduling and Optimization of Wireless Sensor Networks lifetime." Thesis, Université de Lorraine, 2016. http://www.theses.fr/2016LORR0315/document.
Wireless sensor networks (WSNs), as a collection of sensing nodes with limited processing, limited energy reserve and radio communication capabilities, are widely implemented in many areas of applications such as industry, environment, healthcare, etc. Regarding this large range of applications, many research issues are introduced including the applications, performance, reliability, lifetime, etc. The WSNs lifetime considered in this work is the period of time through which theWSN is perfectly completing its function. This lifetime is affected by many factors including the amount of energy available, failure probability and components degradation. The amount of energy available become the most important factor in case of non renewable components applications. Different algorithms, strategies and optimization techniques were developed and implemented for this purpose based on the possibility of activating a subset of sensors that satisfied the monitoring constraint, while keeping the others in sleep mode to be implemented later. This is an NP complete maximization problem that can be solved using disjoint set covers (DSCs). But the solution obtained using DSCs does not extend always significantly the WSNs lifetime. So, the present work aims to search for a better solution using non-disjoint set covers (NDSCs). This approach gives the opportunity for a sensor to be implemented in one or more subset covers. For that purpose, we studied a binary representation based model to maximize the number of NDSCs. Also, we developed a genetic algorithm based heuristic based on this model to find out the maximum number of NDSCs in a reasonable time. Thus, for a set of m sensors used to monitor a set of n targets or a field, this heuristic allows to construct a maximum number q of NDSCs. Additional effort is required to find the best scheduling for implementing the NDSCs so as to maximize the lifetime of the sensors involved in the WSNs, considering their limited available energy. This problem is formulated using integer linear programming (ILP) mathematical model. The objective function of this problem is the sum of all monitoring seasons on which all q NDSCs scheduled, and the constraint is the energy consumption in all sensors included in all NDSCs. Solving this problem using ILP in a period of time depends on the complexity of the model and the instances used. To find the solution in reasonable time, we have developed a NDSCs based genetic algorithm (NDSC-GA). The candidate solutions are represented in chromosomes composed of a number of genes equal to the number q of NDSCs, and each gene is the number of monitoring seasons on which a NDSC is scheduled. We have then developed a GA that combines the four crossover operators and four mutation operators. The GA based methods are coded in C programming language to obtain a satisfying solution and the Cplex software was used to obtain the corresponding exact solution. Comparing the optimal solution obtained using the ILP on small instances, to the solutions obtained using our GA based method explained that our methods can find a solution near the optimal in reasonable time. Then, comparing the solution obtained using our NDSCs GA based methods, to the DSCs GA based method in the literature, we showed that the NDSCs GA can prolong the WSNs lifetime better than DSCs GA for the same instances. Our approach combines together the scheduling principles and the optimization techniques to maximizing the WSNs lifetime
Ahmed, Yousif Elhadi Elsideeg. "Modeling, Scheduling and Optimization of Wireless Sensor Networks lifetime." Electronic Thesis or Diss., Université de Lorraine, 2016. http://www.theses.fr/2016LORR0315.
Wireless sensor networks (WSNs), as a collection of sensing nodes with limited processing, limited energy reserve and radio communication capabilities, are widely implemented in many areas of applications such as industry, environment, healthcare, etc. Regarding this large range of applications, many research issues are introduced including the applications, performance, reliability, lifetime, etc. The WSNs lifetime considered in this work is the period of time through which theWSN is perfectly completing its function. This lifetime is affected by many factors including the amount of energy available, failure probability and components degradation. The amount of energy available become the most important factor in case of non renewable components applications. Different algorithms, strategies and optimization techniques were developed and implemented for this purpose based on the possibility of activating a subset of sensors that satisfied the monitoring constraint, while keeping the others in sleep mode to be implemented later. This is an NP complete maximization problem that can be solved using disjoint set covers (DSCs). But the solution obtained using DSCs does not extend always significantly the WSNs lifetime. So, the present work aims to search for a better solution using non-disjoint set covers (NDSCs). This approach gives the opportunity for a sensor to be implemented in one or more subset covers. For that purpose, we studied a binary representation based model to maximize the number of NDSCs. Also, we developed a genetic algorithm based heuristic based on this model to find out the maximum number of NDSCs in a reasonable time. Thus, for a set of m sensors used to monitor a set of n targets or a field, this heuristic allows to construct a maximum number q of NDSCs. Additional effort is required to find the best scheduling for implementing the NDSCs so as to maximize the lifetime of the sensors involved in the WSNs, considering their limited available energy. This problem is formulated using integer linear programming (ILP) mathematical model. The objective function of this problem is the sum of all monitoring seasons on which all q NDSCs scheduled, and the constraint is the energy consumption in all sensors included in all NDSCs. Solving this problem using ILP in a period of time depends on the complexity of the model and the instances used. To find the solution in reasonable time, we have developed a NDSCs based genetic algorithm (NDSC-GA). The candidate solutions are represented in chromosomes composed of a number of genes equal to the number q of NDSCs, and each gene is the number of monitoring seasons on which a NDSC is scheduled. We have then developed a GA that combines the four crossover operators and four mutation operators. The GA based methods are coded in C programming language to obtain a satisfying solution and the Cplex software was used to obtain the corresponding exact solution. Comparing the optimal solution obtained using the ILP on small instances, to the solutions obtained using our GA based method explained that our methods can find a solution near the optimal in reasonable time. Then, comparing the solution obtained using our NDSCs GA based methods, to the DSCs GA based method in the literature, we showed that the NDSCs GA can prolong the WSNs lifetime better than DSCs GA for the same instances. Our approach combines together the scheduling principles and the optimization techniques to maximizing the WSNs lifetime
Ghigliotti, Giovanni. "Dynamique et rhéologie d'une suspension de vésicules et globules rouges." Phd thesis, Grenoble, 2010. http://www.theses.fr/2010GRENY071.
The dynamics and the rheology of a suspension of vesicles (a model for red blood cells) in the limit of small Reynolds number are studied by means of two-dimensional numerical simulations, based on the boundary integral and phase field methods. The focus is on the link between the microscopic dynamics of the particles and the overall behavior of the suspension (i. E. Rheology). A dilute suspension of vesicles in a linear shear flow is analyzed in detail and the influence of the three parameters governing the dynamics of a single vesicle (reduced volume; viscosity contrast; capillary number) is extensively described. The nontrivial behavior of the rheological quantities (effective viscosity and normal stress difference) is explained and the role of the membrane of the vesicle detailed. The influence of the curvature of the flow lines on the dynamics of the vesicles is investigated for the first time, and consistent inward migration is reported. The suggested interpretation remains valid for the flow of the majority of complex fluids, like emulsions and polymer suspensions, and is thus expected to have an impact in other fields. Moreover, the behavior of a suspension of vesicles in a microscopic Taylor-Couette cell is investigated, and a transition to ordered states is reported at very low volume fraction. The behavior of sets of vesicles in a parabolic flow, a setup that mimics red blood cells in the microvasculature, is presented. Vesicles submitted to sole hydrodynamical interactions are found to form aggregates of finite size, a fact that may prove of physiological interest. Finally, the transposition to red blood cells of the results above is discussed
Demigha, Oualid. "Energy Conservation for Collaborative Applications in Wireless Sensor Networks." Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0058/document.
Wireless Sensor Networks is an emerging technology enabled by the recent advances in Micro-Electro-Mechanical Systems, that led to design tiny wireless sensor nodes characterized by small capacities of sensing, data processing and communication. To accomplish complex tasks such as target tracking, data collection and zone surveillance, these nodes need to collaborate between each others to overcome the lack of battery capacity. Since the development of the batteries hardware is very slow, the optimization effort should be inevitably focused on the software layers of the protocol stack of the nodes and their operating systems. In this thesis, we investigated the energy problem in the context of collaborative applications and proposed an approach based on node selection using predictions and data correlations, to meet the application requirements in terms of energy-efficiency and quality of data. First, we surveyed almost all the recent approaches proposed in the literature that treat the problem of energy-efficiency of prediction-based target tracking schemes, in order to extract the relevant recommendations. Next, we proposed a dynamic clustering protocol based on an enhanced version of the Distributed Kalman Filter used as a prediction algorithm, to design an energy-efficient target tracking scheme. Our proposed scheme use these predictions to anticipate the actions of the nodes and their roles to minimize their number in the tasks. Based on our findings issued from the simulation data, we generalized our approach to any data collection scheme that uses a geographic-based clustering algorithm. We formulated the problem of energy minimization under data precision constraints using a binary integer linear program to find its exact solution in the general context. We validated the model and proved some of its fundamental properties. Finally and given the complexity of the problem, we proposed and evaluated a heuristic solution consisting of a correlation-based adaptive clustering algorithm for data collection. We showed that, by relaxing some constraints of the problem, our heuristic solution achieves an acceptable level of energy-efficiency while preserving the quality of data
Chehade, Tarek. "Optimisation d'un précodeur MIMO-OFDM dans le contexte de l'estimation aveugle et semi-aveugle du canal de communication." Thesis, Brest, 2015. http://www.theses.fr/2015BRES0077/document.
Channel estimation plays an important role in wireless mobile communications, especially in MIMO systems. Unlike conventional channel estimation techniques based on training sequences or pilot symbols, blind techniques does not require the insertion of training symbols and allow higher throughput. The main problems of the blind lies in the ambiguity over the estimated channel. Based on the same methods as the blind estimation, the semi-blind estimation techniques are more robust. They exploit the blind information along with information provided by a small number of training symbols. The channel estimation is useful in MIMO systems and allows the precoding of the MIMO-OFDM signal by applying a pre-mixture in order to improve performance. Many types of precoders exist and their performance varies depending not only on the optimization criteria (Water-Filling, MMSE, Equal Error, max-SNR, max-d min ...), but also on the estimated channel. In this thesis we study the impact of using the channel information (CSI) from the blind and semi-blind estimation techniques to apply MIMO linear precoders. We also present a statistical study of the estimation error of these methods. The optimization of these precoders leads eventually to use another process allowing more performance improvement: the error correcting codes. We are particularly interested in non-binary LDPC codes and their association with linear MIMO precoders. We show that a matching is possible, and is beneficial in some cases. The optimization of this combination has allowed us to propose a new robust and more efficient precoder based on the maximization of mutual information
Kouassi, Boris Rodrigue. "Stratégies de coopération dans les réseaux radio cognitif." Phd thesis, Université Nice Sophia Antipolis, 2013. http://tel.archives-ouvertes.fr/tel-00921559.
Boulos, Karen. "BBU-RRH Association Optimization in Cloud-Radio Access Networks." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS209/document.
The demand on mobile traffic has been largely increasing nowadays. Facing such growth, several propositions are being studied to cope with this challenge. Cloud-Radio Access Networks Architecture (C-RAN) is one of the proposed solutions to address the increased demand, and is a potential candidate for future 5G networks. The C-RAN architecture dissociates two main elements composing the base station: The Baseband Unit (BBU), consisting in an intelligent element to perform baseband tasks functionalities, and the Remote Radio Head (RRH), that consists in a passive antenna element to provide access for serviced User Equipments (UEs). In C-RAN architecture, the BBUs migrate to a Cloud data center, while RRHs remain distributed across multiple sites. Several advantages are derived, such as statistical multiplexing gain, efficiency in resource utilization and power saving. Contrarily to conventional architecture, where each RRH is associated to one BBU, in C-RAN architecture, multiple RRHs can be embraced by one single BBU when network load conditions are low, bringing along several benefits, such as enhanced energy efficiency, and power consumption minimization. In this thesis, the BBU-RRH association optimization problem is addressed. Our aim is to optimize the BBU-RRH association schemes, taking into consideration several criteria. The problem presents many constraints: For example, achieving minimized power consumption while guaranteeing a minimum level of Quality of Service (QoS) is a challenging task. Further, taking into account the interference level variation while turning ON/OFF BBUs is paramount to achieve enhanced spectral efficiency. Moreover, deciding how to re-associate RRHs to BBUs under dynamic load conditions is also a challenge, since connected UEs face handovers (HOs) when RRHs change their associations
Lardin, Pauline. "Estimation de synchrones de consommation électrique par sondage et prise en compte d'information auxiliaire." Phd thesis, Université de Bourgogne, 2012. http://tel.archives-ouvertes.fr/tel-00842199.
Wang, Chenghao. "Contribution à l’optimisation robuste de réseaux." Thesis, Compiègne, 2021. http://www.theses.fr/2021COMP2632.
This Ph.D. Thesis is focused on proposing new optimization modeling and algorithmic approaches for dealing with real-world network optimization problems arising in the transportation and telecommunications fields. Since the focus has been on real-world applications, a relevant aspect that has been taken into account is data uncertainty, i.e. the fact that the value of a subset of input data of the problem is not exactly known when the problem is solved. More precisely, in the context of transportation problems, it was considered the flight level assignment problem, which arises in air traffic management. It aims at establishing the flight levels of a set of aircraft in order to improve the total assignment revenue, to reduce the total number of flight conflicts and also the total en-route delay. In this context, we proposed a new chance-constrained optimization problem and iterative constraint-generation heuristic which is based on both analytical and sampling methods. Besides transportation problems, this Thesis has also focused on the optimal design of 5th generation of wireless networks (5G) considering Superfluid and virtual architectures. Specifically, the 5G Superfluid architecture is based on atomic virtual entities called Reusable Functional Block (RFB). We investigated the problem of minimizing the total installation costs of a 5G Superfluid network (composed of virtual entities and realized over a physical network) while guaranteeing constraint on user coverage, downlink traffic performance and technical constraints on RFBs of different nature. To solve this hard problem, we proposed a Benders decomposition approach. Concerning instead the design of general virtual networks, we adopted a green paradigm that pursues energy-efficiency and tackled a state-of-the-art robust mixed integer linear programming formulation of the problem, by means of a new matheuris tic based on combining a genetic algorithm with exact large neighborhood searches. Results of computational tests executed considering realistic problem instances have shown the validity of all the new optimization modeling and algorithmic approaches proposed in this Thesis for the transportation and telecommunications problems sketched above
Masucci, Antonia Maria. "Moments method for random matrices with applications to wireless communication." Thesis, Supélec, 2011. http://www.theses.fr/2011SUPL0011/document.
In this thesis, we focus on the analysis of the moments method, showing its importance in the application of random matrices to wireless communication. This study is conducted in the free probability framework. The concept of free convolution/deconvolution can be used to predict the spectrum of sums or products of random matrices which are asymptotically free. In this framework, we show that the moments method is very appealing and powerful in order to derive the moments/asymptotic moments for cases when the property of asymptotic freeness does not hold. In particular, we focus on Gaussian random matrices with finite dimensions and structured matrices as Vandermonde matrices. We derive the explicit series expansion of the eigenvalue distribution of various models, as noncentral Wishart distributions, as well as correlated zero mean Wishart distributions. We describe an inference framework so flexible that it is possible to apply it for repeated combinations of random ma- trices. The results that we present are implemented generating subsets, permutations, and equivalence relations. We developped a Matlab routine code in order to perform convolution or deconvolution numerically in terms of a set of input moments. We apply this inference framework to the study of cognitive networks, as well as to the study of wireless networks with high mobility. We analyze the asymptotic moments of random Vandermonde matrices with entries on the unit circle. We use them and polynomial expansion detectors in order to design a low complexity linear MMSE decoder to recover the signal transmitted by mobile users to a base station or two base stations, represented by uniform linear arrays
Geamanu, Marcel-Stefan. "Estimation and dynamic longitudinal control of an electric vehicle with in-wheel electric motors." Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-00871231.