Teses / dissertações sobre o tema "Risque de propagation"
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Lignon, Sylvain. "Approche robuste du risque sismique". Ecully, Ecole centrale de Lyon, 2006. http://bibli.ec-lyon.fr/exl-doc/slignon.pdf.
Texto completo da fonteAt present, the question of seismic modelling is still very open. The work reported in this document proposes a modelling of the whole of the chain, from the description of the initialization of the earth tremor until the damage of the reinforced concrete structure, while passing by the transmission of the wave through the ground, the goal being to implement a robust approach of the damage structure. A decoupling of the various phenomena is introduced, in order to work on simplified models on each level. To start, an original model of seismic fault is developed, the 3S model. The wave propagation is then studied by regarding the ground as a stratified medium. Lastly, uncertainties are taken into account in the evaluation of the damage of the structures. Specific methods of convex analysis are then implemented
Hessas, Nassima. "Évaluation cartographique et évolution diachronique par télédétection du risque incendie de forêt : simulation de la propagation du feu dans le bassin versant du Paillon, Nice, Alpes-Maritimes". Université Joseph Fourier (Grenoble), 2005. http://www.theses.fr/2005GRE10248.
Texto completo da fonteDue to its climate and mountainous relief, as well as the tourism, urban and economic stakes involved, Alpes-Maritimes is the most exposed to fire risks. This thesis has sought to detect and locate risks, then assess their consequences. In order to study the environmental impacts of fires, it was necessary to determine how often and where they occur. As vast areas are involved, remote sensing by aerial or satellite photography is one of the means of understanding such large-scale phenomena. Yearly statistical were made of 30 years of fires, first over the whole department, then town by town, on the basis of the following questions: What are the causes? How often do fires occur and of what amplitude? Do weather conditions play a part in starting and spreading fires? Why was summer 2003 such a catastrophe? The use of GIS for cartographic assessment was shown to be an efficient scientific tool for examining and highlighting exposure to hazard as well as for expressing vulnerability and determining the zoning which developers, prescribers and decision makers incorporate in their overall approach to local development at various appropriate. The multiplication of classifications and PCA of a satellite picture and the FCA of the entire basin contribute considerably to understanding the phenomenon. Forest fires engender fundamental modifications of land use and zoning. A diachronic study of the evolution of the Paillon, based on 3 series of aerial photographs and with the help of remote sensing and GIS, enabled extremely precise spatial-temporal dimensions to be determined. Studying simulations of the way fires spread can help with decision-making
Baudrit, Cédric. "Représentation et propagation de connaissances imprécises et incertaines : application à l'évaluation des risques liés aux sites et aux sols pollués". Phd thesis, Université Paul Sabatier - Toulouse III, 2005. http://tel.archives-ouvertes.fr/tel-00011933.
Texto completo da fontesur une évaluation des risques pour l'homme et l'environnement. Cette évaluation est effectuée à l'aide de modèles qui simulent le transfert de polluant depuis une source de pollution vers une cible vulnérable, pour différents scénarii d'exposition. La sélection des valeurs des paramètres de ces modèles s'appuie autant que possible sur les données recueillies lors des investigations de terrain (phase de diagnostic de site). Or pour des raisons de délais et de coûts, l'information recueillie lors de cette phase de diagnostic est toujours incomplète; elle est donc entachée d'incertitude. De même, les modèles de transferts et d'exposition présentent également des incertitudes à intégrer dans les procédures. Cette notion globale d'incertitude doit être prise en compte dans l'évaluation du risque pour que les résultats soient utiles lors la phase décisionnelle.
L'incertitude sur les paramètres peut avoir deux origines. La première provient du caractère aléatoire de l'information due à une variabilité naturelle résultant de phénomènes stochastiques. On parle alors d'incertitudes de variabilité ou d'incertitudes stochastiques. La seconde est liée au caractère imprécis de l'information lié à un manque de connaissance et qui résulte par exemple d'erreurs systématiques lors de mesures ou d'avis d'experts.
On parle alors d'incertitudes épistémiques. Dans le calcul de risque, ces deux notions sont souvent confondues alors qu'elles devraient être traitées de manière différente.
L'incertitude en évaluation des risques a surtout été appréhendée dans un cadre purement probabiliste.
Cela revient à supposer que la connaissance sur les paramètres des modèles est toujours de nature aléatoire (variabilité). Cette approche consiste à représenter les paramètres incertains par des distributions de probabilité uniques et à transmettre l'incertitude relative à ces paramètres sur celle du risque encouru par la cible, en appliquant en général la technique dite Monte Carlo. Si cette approche est bien connue, toute la difficulté tient à une définition cohérente des distributions de probabilité affectées aux paramètres par rapport à la connaissance disponible. En effet dans un contexte d'évaluation des risques liés à l'exposition aux polluants, l'information dont on dispose concernant certains paramètres est souvent de nature imprécise. Le calage d'une distribution de probabilité unique sur ce type de
connaissance devient subjectif et en partie arbitraire.
L'information dont on dispose réellement est souvent plus riche qu'un intervalle mais moins riche qu'une distribution de probabilité. En pratique, l'information de nature aléatoire est traitée de manière rigoureuse par les distributions de probabilité classiques. Celle de nature imprécise est traitée de manière rigoureuse par des familles de distributions de probabilité définies au moyen de paires de probabilités cumulées hautes et basses ou, à l'aide de théories plus récentes, au moyen de distributions de possibilité (aussi appelées intervalles flous) ou encore au moyen d'intervalles aléatoires utilisant les fonctions de croyance de Dempster-Shafer.
Un des premiers objectifs de ce travail est de promouvoir la cohérence entre la manière dont on représente la connaissance sur les paramètres
des modèles du risque et la connaissance dont on dispose réellement. Le deuxième objectif est de proposer différentes méthodes pour propager l'information de nature aléatoire et l'information de nature imprécise à travers les modèles du risque tout en essayant de tenir compte des dépendances entre les paramètres. Enfin, ces méthodes alternatives ont été testées sur des cas synthétiques puis sur des cas réels simplifiés, notamment pour proposer des moyens de présenter les résultats pour une phase décisionnelle:
- Calcul de dose : Transfert d'un polluant radioactif (le strontium) depuis le dépôt jusqu'à
l'homme, au travers de la consommation d'un aliment (le lait de vache).
- Risque toxique après un déversement accidentel de trichloréthylène (TCE) au dessus d'une nappe d'eau (modèle semi analytique).
- Risque pour la santé liée aux sols pollués par des retombées de plomb.
Favier, Philomène. "Une approche intégrée du risque avalanche : quantification de la vulnérabilité physique et humaine et optimisation des structures de protection". Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENU051/document.
Texto completo da fonteLong term avalanche risk quantification for mapping and the design of defense structures is done in mostcountries on the basis of high magnitude events. Such return period/level approaches, purely hazardoriented,do not consider elements at risk (buildings, people inside, etc.) explicitly, and neglect possiblebudgetary constraints. To overcome these limitations, risk based zoning methods and cost-benefit analyseshave emerged recently. They combine the hazard distribution and vulnerability relations for the elementsat risk. Hence, the systematic vulnerability assessment of buildings can lead to better quantify the riskin avalanche paths. However, in practice, available vulnerability relations remain mostly limited to scarceempirical estimates derived from the analysis of a few catastrophic events. Besides, existing risk-basedmethods remain computationally intensive, and based on discussable assumptions regarding hazard modelling(choice of few scenarios, little consideration of extreme values, etc.). In this thesis, we tackle theseproblems by building reliability-based fragility relations to snow avalanches for several building types andpeople inside them, and incorporating these relations in a risk quantification and defense structure optimaldesign framework. So, we enrich the avalanche vulnerability and risk toolboxes with approaches of variouscomplexity, usable in practice in different conditions, depending on the case study and on the time availableto conduct the study. The developments made are detailed in four papers/chapters.In paper one, we derive fragility curves associated to different limit states for various reinforced concrete(RC) buildings loaded by an avalanche-like uniform pressure. Numerical methods to describe the RCbehaviour consist in civil engineering abacus and a yield line theory model, to make the computations asfast as possible. Different uncertainty propagation techniques enable to quantify fragility relations linkingpressure to failure probabilities, study the weight of the different parameters and the different assumptionsregarding the probabilistic modelling of the joint input distribution. In paper two, the approach is extendedto more complex numerical building models, namely a mass-spring and a finite elements one. Hence, muchmore realistic descriptions of RC walls are obtained, which are useful for complex case studies for whichdetailed investigations are required. However, the idea is still to derive fragility curves with the simpler,faster to run, but well validated mass-spring model, in a “physically-based meta-modelling” spirit. Inpaper three, we have various fragility relations for RC buildings at hand, thus we propose new relationsrelating death probability of people inside them to avalanche load. Second, these two sets of fragilitycurves for buildings and human are exploited in a comprehensive risk sensitivity analysis. By this way,we highlight the gap that can exist between return period based zoning methods and acceptable riskthresholds. We also show the higher robustness to vulnerability relations of optimal design approaches ona typical dam design case. In paper four, we propose simplified analytical risk formulas based on extremevalue statistics to quantify risk and perform the optimal design of an avalanche dam in an efficient way. Asensitivity study is conducted to assess the influence of the chosen statistical distributions and flow-obstacleinteraction law, highlighting the need for precise risk evaluations to well characterise the tail behaviour ofextreme runouts and the predominant patterns in avalanche - structure interactions
Boulanger, Xavier. "Modélisation du canal de propagation Terre-Espace en bandes Ka et Q/V : synthèse de séries temporelles, variabilité statistique et estimation de risque". Thesis, Toulouse, ISAE, 2013. http://www.theses.fr/2013ESAE0009/document.
Texto completo da fonteNowadays, C and Ku bands used for fixed SATCOM systems are totally congested. However, the demand of the end users for high data rate multimedia services is increasing. Consequently, the use of higher frequency bands (Ka: 20 GHz and Q/V 40/50 GHz) is under investigation. For frequencies higher than 5 GHz, radiowave propagation is strongly affected by tropospheric attenuation. Among the different contributors, rain is the most significant. To compensate the deterioration of the propagation channel, Fade Mitigation Techniques (FMT) are used. The lack of experimental data needed to optimize the real-time control loops of FMT leads tothe use of rain attenuation and total attenuation time series synthesizers. The manuscript is a compilation of five articles. The first contribution is dedicated to the temporal modelling of total impairments. The second article aims at providing significant improvements on the rain attenuation time series synthesizer recommended by ITU-R. The last three contributions are a critical analysis and a modelling of the variability observed on the 1st order statistics used to validate propagation channel models. The variance of the statistical estimator of the complementary cumulative distribution functions of rainfall rate and rain attenuation is highlighted. A worldwide model parameterized in compliance with propagation measurements is proposed. It allows the confidence intervals to be estimated and the risk on a required availability associated with a given propagation margin prediction to be quantified. This approach is extended to the variability of joint statistics. It allows the impact of site diversity techniques on system performances at small scale (few kms) and large scale (few hundred of kms) to be evaluated
Salines, Morgane. "Modélisation de la propagation du virus de l'hépatite E dans la filière porcine et évaluation de stratégies de réduction du risque d'exposition humaine". Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1B039/document.
Texto completo da fonteHepatitis E virus (HEV) is a zoonotic pathogen whose main reservoir in industrialised countries is pigs. This research project combined epidemiological studies, mathematical modelling and social sciences to propose levers for reducing the risk of human exposure to HEV through the consumption of pork products. Two experimental trials and one study under natural conditions highlighted the major role of immunomodulating co-infections on the dynamics of HEV infection in pigs, as these intercurrent pathogens led to chronic HEV infection and an increased risk of the virus in the liver, blood and muscles of slaughtered animals. The development of a within-herd, stochastic, individual-based and multi-pathogen model has made it possible to identify both zootechnical and sanitary control measures to reduce the prevalence of the virus on farms. In addition, the design of a between-herd model has enabled to analyse the factors responsible for the spread of the virus in a network of French farms. All these HEV control measures have been submitted for the opinion of public and private organisations and individual players in the pig sector (farmers, farming advisors, veterinarians) through social science approaches. Finally, this transversal and multidisciplinary project made it possible to define tangible and achievable lines of action for the management of HEV in the pig sector while making significant methodological contributions in epidemiology and modelling
Heipertz, Jonas. "Three Essays in Financial Networks and Shock Propagation". Thesis, Paris, EHESS, 2019. http://www.theses.fr/2019EHES0106.
Texto completo da fonteFinancial inter-dependencies are since the financial crisis at the forefront of macroeconomic research and policy making. The world had painfully learned how small and localized events can travel through the global financial system with huge repercussions for the real economy. Since then, many studies have analyzed the propagation properties of given financial exposure networks. Each day, however, large amounts of financial assets are traded and financial institutions’ balance-sheets change in response to new information, regulation or monetary policy. Changes in exposures crucially affect the transmission of shocks. This thesis develops general equilibrium frameworks that show how financial networks emerge endogenously from trade in financial assets between heterogeneous institutions. I use micro and macro-level datasets including confidential data from the Banque de France to structurally identify risk-preferences, institutions' beliefs about the distribution of future financial asset returns, and the specific constraints that drive financial network formation. The thesis also derives an explicit firm-level link of financial networks to an economy's productive structure.Chapter 1 of the thesis shows how firm-level productivity shocks propagate through financial networks. If firms need external funds to finance capital expenditure, banks create linkages between them that go beyond their input-output relationships. These links can affect aggregate output. The chapter builds a multi-sector production model of heterogeneous firms that are financed by heterogeneous leverage targeting banks. Banks are themselves connected through bilateral cross-holdings. Endogenous financial asset prices introduce a new propagation channel of productivity shocks. Structural parameters such as bank-level leverage constraints determine the strength of this channel and one statistic is sufficient to capture it. I use confidential matched bank-firm-level data from the Banque de France on corporate bond investments to estimate the model. The model can be used to study macro-prudential regulation and monetary policy.Chapter 2 uses bank- and instrument-level data on asset holdings and liabilities to identify and estimate a general equilibrium model of trade in financial instruments shaping an endogenous network of interlinked banks' balance-sheets. Bilateral ties are formed as each bank selects the size and the diversification of its assets and liabilities. Shocks propagate due to the response, rather than the size, of bilateral ties to such shocks. The network exhibit key theoretical properties: (i) more connected networks lead to less amplification of partial equilibrium shocks, (ii) the influence of a bank's equity is independent of the size of its holdings; (iii) more risk-averse banks are more diversified, lowering their own volatility but increasing their influence on other banks. The structural estimation of the network model for the universe of French banks shows that the endogenous change in the network matters two to three times more than the initial network of cross-holdings for the transmission of shocks. The estimated network is used to assess the effects of the ECB's quantitative easing policy.Chapter 3 concludes the thesis with a more aggregated sector-level analysis. It first studies how the sharp deterioration of the net external portfolio position of France between 2008 and 2014 was driven by sectoral patterns such as the banking sector retrenchment and the increase in foreign liabilities of the public and corporate sectors but was mitigated by the expansion of domestic and foreign asset portfolios of insurance companies. It provides a network representation of the links between domestic sectors and the rest of the world. Sectoral shock propagation through inter-sectoral security holdings is studied in an estimated balance-sheet contagion model
Fang, Chao. "Modeling and Analysing Propagation Behavior in Complex Risk Network : A Decision Support System for Project Risk Management". Phd thesis, Ecole Centrale Paris, 2011. http://tel.archives-ouvertes.fr/tel-01018574.
Texto completo da fonteGrondin, Julien. "Evaluation ultrasonore de l'os cortical en transmission transverse : études numérique et expérimentale de la propagation d’ondes circonférentielles pour la caractérisation de la résistance mécanique du col fémoral". Paris 6, 2010. http://www.theses.fr/2010PA066434.
Texto completo da fonteAnker, Wolfram. "Représentation spatiale des risques de propagation des pollutions par hydrocarbures en milieu souterrain : application en milieu alluvial". Phd thesis, Ecole Nationale Supérieure des Mines de Paris, 1997. http://tel.archives-ouvertes.fr/tel-00825624.
Texto completo da fonteDarmet, Natacha. "Prise en compte du risque de propagation de l'emballement thermique dans le développement des modules de batteries. Approche expérimentale tenant compte de la génération de gaz". Electronic Thesis or Diss., Université Grenoble Alpes, 2024. http://www.theses.fr/2024GRALI024.
Texto completo da fonteLithium-ion batteries are playing a prominent role in the energy transition, particularly in terms of storage and transportation. The analysis of failure modes reveals that despite of a low probability, the battery self heating has consequences that requires mitigation. Studying the phenomena that lead to the propagation from a cell’s thermal runaway to neighboring cells is essential. The key parameters involved in the thermal runaway propagation for a battery module are evaluated in details in this thesis. Different approaches based on a plurality of characterization methods are proposed. Still, some mechanisms need further developments through specific measures at each stage of the phenomenon.When incidents occur, the cell’s materials react by producing gas, which mechanically affects the cell casing. An experimental device has been developed to measure the internal pressure of the cell, allowing an operando monitoring of this gas generation. The correlation of this measurement with the casing deformations also confirms the significant impact of electrode swelling on the casing’s mechanical strength.At a critical temperature, the lithium-ion cell initiates thermal runaway, which leads to the ejection of materials (gas, flame, particles) at high temperature. Pressure sensors and fast cameras at different spectra were used to analyze the jet dynamics, from its genesis in the cell to its ejection.Heat transfers then occur between the ejecta and surrounding cells, which can results in a thermal runaway propagation. Calorimetry was used to characterize the first cell in order to predict its thermal exchanges in different configurations. Then, based on the knowledge of this energy release and the jet dynamics, a calculation of the emitted heat flow is proposed. The X-rays observations of the active material during the thermal runaway propagation revealed that degradation kinetics and gas generation are linked. It also stresses the importance of trigger cell particles in the thermal propagation risks.Lastly, the thermal runaway propagation between rebuilt charged all-solid-states batteries cells were evaluated experimentally, for the first time. This research has demonstrated that the propagation is feasible with these new battery technologies. The study must be conducted further
Laurent, Pierre. "Etude de la vitesse de propagation de l'onde de pouls : de la recherche expérimentale à la pratique clinique". Bordeaux 2, 1994. http://www.theses.fr/1994BOR2M132.
Texto completo da fonteDelepine, Nicolas. "Modélisation des effets de site sismiques dans les bassins sédimentaires et influence des non-linéarités de comportement des sols". Phd thesis, Ecole des Ponts ParisTech, 2007. http://pastel.archives-ouvertes.fr/pastel-00003827.
Texto completo da fonteChandra, Johanes. "Analyses expérimentales de la réponse sismique non-linéaire du système sol-structure". Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENU023/document.
Texto completo da fonteThe concentration of population in urban areas in seismic-prone regions can generate more and more damages and losses. Seismic response in urban areas depends on site effects (direct amplification and nonlinearity of the soil) and the coupling between the soil and structures (soil-structure and site-city interaction). Therefore, the understanding of urban seismology, that is the ground motion incorporating the urban environment, is critical to reduce the damage. This requires the prediction of ground motion in urban areas, a fundamental element in the evaluation of the seismic hazard. Taking into account the amplification caused by the presence of sediment has been widely studied. However, the non-linearity of the soil and the coupling between the ground and the structure is seldom integrated to the prediction of the ground motion. Because of their complexity, these problems have been addressed separately. In this context, this dissertation analyzes the non-linear response of the soil-structure by integrating the non-linearity of the soil and the soil-structure interaction. Two experimental studies were performed, with the aim of providing a proxy that reflects the non-linearity of the soil. The first is the centrifuge test that reproduces the response of soil and structures at reduced scale. The state of stress and strain is conserved by applying an artificial acceleration model. This test was performed at IFSTTAR Nantes in the framework of the ANR ARVISE. Different configurations were tested with and without buildings, under different stress levels, to analyze the response of the soil and structures. The second uses the vertical accelerometric networks of two sites in California: Garner Valley Downhole (GVDA) and the Wildlife Liquefaction Array (WLA), both managed by the University of California, Santa Barbara (UCSB), USA. In-situ response is important since it describes the actual behavior of the site. Information describing the conditions of sites is widely available and the earthquakes recorded were used to test several levels of shaking to reconstruct the overall response of each site. In addition, the GVDA site is equipped with a Soil-Foundation-Structure-Interaction structure (SFSI) which aims to study the problems of soil-structure interaction. In both experiments, thanks to the vertical accelerometer network in the ground and the structure we are able to apply the 1D wave propagation method to extract the response of these systems. The waves are considered as an SH wave which propagates in a 1D horizontal layer. Seismic interferometry by deconvolution method is applied to extract the Impulse Response Function (IRF) of the 1D system. Thus the analysis of the variation in function of elastic properties of the soil and the structure is done under several magnitude of shaking, including variation in depth and the elements of the total response of the structure including the soil-structure interaction. At the end, a deformation proxy to evaluate and also to predict the nonlinear response of the soil, the structure and the soil-structure interaction is proposed
Houret, Thomas. "Méthode d’estimation des valeurs extrêmes des distributions de contraintes induites et de seuils de susceptibilité dans le cadre des études de durcissement et de vulnérabilité aux menaces électromagnétiques intentionnelles". Thesis, Rennes, INSA, 2019. http://www.theses.fr/2019ISAR0011.
Texto completo da fonteIntentional ElectroMagnetic Interference (IEMI) can cause equipment failure. The study of the effects of an IEMI begins with an assessment of the risk of equipment failure in order to implement appropriate protections, if required. Unfortunately, a deterministic prediction of a failure is impossible because both characteristics of equipment and of the aggression are very uncertain. The proposed strategy consists of modelling the stress generated by the aggression, as well as the susceptibility of the equipment, as random variables. Then, three steps are necessary: The first step deals with the estimation of the probability distribution of the random susceptibility variable. The second step deals with the similar estimation for the constraint / stress then that of the stress. Eventually, the third step concerns the calculation of the probability of failure. For the first step, we use statistical inference methods on a small sample of measured susceptibility thresholds. We compare two types of parametric inference: bayesian and maximum likelihood. We conclude that a relevant approach for a risk analysis is to use the confidence or credibility intervals of parameter estimates to frame the probability of failure, regardless of the inference method chosen. For the second step we explore extreme value exploration techniques while reducing the number of simulations required. In particular, we propose the technique of Controlled Stratification by Kriging. We show that this technique drastically improves performance compared to the classic approach (Monte Carlo simulation). In addition, we propose a particular implementation of this technique in order to control the calculation effort. Finally, the third step is the simplest once the first two steps have been completed since, by definition, a failure occurs when the stress is greater than the susceptibility. With the help of a final test case comprising the simulation of an electromagnetic aggression on a piece of equipment, we use the method developed in our work to estimate the frame of the probability of failure, More specifically, we show that the combined use of controlled stratification by kriging and inference of susceptibility distribution, allows to frame the estimated true value of the probability of failure
Okhulkova, Tatiana. "Integration of uncertainty and definition of critical thresholds for CO2 storage risk assessment". Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLC021/document.
Texto completo da fonteThe main goal of the thesis is to define how the uncertainty can be accounted for in the process of riskassessment for CO2 storage and to quantify by means of numerical models the scenarii of leakage by lateralmigration and through the caprock. The chosen scenarii are quantified using the system modeling approachfor which ad-hoc predictive numerical models are developed. A probabilistic parametric uncertaintypropagation study using polynomial chaos expansion is performed. Matters of spatial variability are alsodiscussed and a comparison between homogeneous and heterogeneous representations of permeability isprovided
Diab, Ahmad. "Study of the nonlinear properties and propagation characteristics of the uterine electrical activity during pregnancy and labor". Thesis, Compiègne, 2014. http://www.theses.fr/2014COMP2140/document.
Texto completo da fonteThe uterine EMG -called Electrohysterogramme (EHG)- temporal, frequency, and time-frequency characteristics have been used for a long time for the prediction of preterm labor. However, the investigation of its propagation is rare. All the results of the previous studies did not show a satisfactory potential for clinical application. The objective of this thesis is the analysis of the propagation as well as of the nonlinear characteristics of EHG signals during pregnancy and labor for clinical application. A monovariate analysis was done to investigate the nonlinearity and the sensibility of methods to different characteristics of the signals. A bivariate analysis was then done for the investigation of the propagation of EHG by measuring the coupling between channels, as well as the direction of coupling, which is an innovative part of our thesis. In this analysis we propose a new approach to improve the coupling and direction estimation methods. Another innovation of this thesis is the implementation of a tool for EHG source localization to investigate the dynamic of the uterus at the source level, not at electrodes level as previously done. Results show that nonlinear methods are more able to classify pregnancy and labor contractions than linear ones, and that time reversibility method is the least sensitive to sampling frequency and frequency content of the signal. Results also indicate an increase in coupling and a concentration of coupling direction toward the cervix when going from pregnancy to labor. We also proposed to respect the nonstationarity of EHG signal and to recover the effect of variable fat filtering along pregnancy, by segmenting and filtering the EHG in its FWL component. This filtering-windowing approach permits to improve the performances of connectivity methods. Finally, the intensity of localized sources and their number is higher in labor than in pregnancy contractions. The identified sources are more active and more propagated in labor whereas in pregnancy they remain weak and local. An improvement in the electrode matrix of the rat experimental protocol has also been done by developing a suction electrode. This protocol can then be used for the validation of our methods and of the electrophysiological model
Boukraa, Lotfi. "Simulation of wireless propagation in a high-rise building". Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Dec%5FBoukraa.pdf.
Texto completo da fonteDiquélou, Laurent. "Propagation des signaux sur les lignes d'énergie électrique : étude des risques de compromission par rayonnement". Thesis, Lille 1, 2010. http://www.theses.fr/2010LIL10052.
Texto completo da fonteThe aim of this thesis was to study the possibility for power lines to emit compromising electromagnetic radiations. We focused on two cases. The first one was inside buildings, on PLC “Power Line Communication”. The second one was outside, on an industrial site, and about propagation and radiation of the characteristic signals produced by an industrial material.In the first case, we describe, measuring and modeling, the mechanisms involved in radiation cable Low Voltage (LV). There are two channels of propagation. The first is "wired" and the usual channel of a PLC link between two modems. The second channel is "wireless", which corresponds to the reception, across a magnetic antenna, of a differential injection of 2 lines of the cable. Both types of propagation channels are characterized experimentally, which enable us to deduced, using software, the decoding possibility of the information carried out by the compromising emanations.In the second case, considering "High Voltage" (HV) lines, we studies the successive transfer functions of the current associated with the spread on LV lines, crossing the transformer LV / HV, and then spreading on HV lines. Modelings were performed using commercial software EMTP. The results were compared with experimental measurements obtained during our study. HV lines radiations are discussed both from a theoretical and an experimental perspective
Fang, Chao. "Modélisation et Analyse de Propagation dans un Réseau Complexe de Risques : Un système D'aide à la Décision Pour la Gestion des Risques Projet". Phd thesis, Ecole Centrale Paris, 2011. http://tel.archives-ouvertes.fr/tel-00699953.
Texto completo da fonteAlileche, Nassim. "Etude des effets dominos sur une zone industrielle". Thesis, Rouen, INSA, 2015. http://www.theses.fr/2015ISAM0013.
Texto completo da fonteDomino effects or cascading events in the chemical and process industries are recognized as credible accident scenarios since three decades. They are raising a growing concern, as they have the potential to cause catastrophic consequences. Domino effect, as phenomenon, is still a controversial topic when coming to its assessment. There is still a poor agreement on the definition of domino effect and its assessment procedures. A number of different definitions and approaches are proposed in technical standards and in the scientific literature. Therefore, one of this research objectives is to formalize domino effects knowledges in order to comprehend their occurrence mechanisms. Thus, the parameters that should be looked at so as to understand the escalation possibility and in order to identify domino scenarios, were analyzed. The aim is to improve domino effect hazards prevention, through the development of a methodology for the identification and the analysis of domino effects.We developed a method for the analysis of domino accident chain caused by loss of containments. It allow the identification and prioritization of accident propagation paths. The method is user-friendly and help decision making regarding the prevention of cascading events. The final outcomes of the model are given in form of quantitative rankings of equipment involved in domino scenarios, taking into account the effect of meteorological conditions and safety barriers. The rankings give a clear idea of equipment hazard for initiating or continuing cascading events.The methodology is based on a topography of the industrial area of concern, including the characteristics of each unit and accounting for protection and mitigation barriers. It is based on two main stages. The first is the identification of accident propagation paths. For this, the event tree method is used. The possible targets are identified combining the escalation thresholds and vulnerability models (to estimate damage probability). This first stage was implemented using the MATLAB® software and Visual Basic for Applications (VBA) to enable an easy input procedure and output analysis in Microsoft Excel®.The second stage is the identification of the most dangerous equipment. It consists in prioritizing equipment involved in the propagation paths according to their likelihood to cause/propagate domino effect. The algorithm that performs this phase was coded in VBA.The method was designed so as it can be used without the need to rely on the results of safety reports. However, if such results are available, it is possible to lighten some steps of the method. It revealed easy to apply, this was confirmed through projects and student internships
Gli effetti domino, in cui un primo incidente causa in cascata altri scenari incidentali, sono tragli scenari incidentali più severi che avvengono nell’industria chimica. Nonostante l’attenzioneche anche la normativa dedica a tali scenari, la valutazione dell’effetto domino è un soggettocontroverso. L’analisi della letteratura tecnica e scientifica ha mostrato l’assenza di unadefinizione comune di « effetto domino » e di una semplice procedura per l’identificazione ditali scenari. È per tale motivo che uno degli obiettivi di questo lavoro di ricerca è diformalizzare le conoscenze relative agli effetti domino al fine di meglio comprendere imeccanismi che possono provocarli. A tal proposito sono stati studiati i parametri necessariper determinare la possibilità dell’insorgere di cascate di eventi e per essere in grado diidentificare i possibili scenari incidentali dovuti ad effetto domino. L’obiettivo finale del lavoroè stato di sviluppare un metodo per l’identificazione e l’analisi quantitativa della propagazionedi incidenti primari nell’ambito di scenari dovuti ad effetto domino.E’ stata sviluppata una metodologia generale per l’analisi degli effetti domino causati daperdite di confinamento. Tale metodologia permette l’identificazione e la classificazione deipercorsi di propagazione degli incidenti. Tale metodo facilita inoltre la prevenzione deglieffetti domino, proponendo uno strumento efficace e semplice da utilizzare.I risultati di questo studio sono forniti in forma di una classificazione delle apparecchiaturecoinvolte in scenari dovuti ad effetto domino, tenendo conto degli effetti delle condizionimeteorologiche e delle misure esistenti per la gestione del rischio. Tale classificazione fornisceanche un chiara idea dei pericoli rappresentati dalle singole apparecchiature nel caso diincidenti in cascata, in quanto precisando se la pericolosità delle attrezzature proviene dallaloro capacità di innescare o propagare un reazione a catena.Il metodo è basato su una descrizione topografica del sito studiato, che comprende anche lecaratteristiche di ogni attrezzatura, che tiene conto delle misure di gestione dei rischi e dellebarriere di sicurezza presenti, basato su due fasi principali. La prima è l’identificazione deipercorsi di propagazione degli incidenti. A tale scopo è stato utilizzato un metodo basatoVIsull’albero degli eventi. I potenziali bersagli vengono determinati combinando i valori di sogliaper la propagazione degli eventi ed i modelli di vulnerabilità delle apparecchiature. Questaprima fase è implementata in MATLAB® e Visual Basic for Applications (VBA) in modo dafacilitare la gestione dei dati e l’analisi dei risultati in Microsoft Excel®.La seconda fase è l’identificazione delle apparecchiature più pericolose per gli effetti domino.Tale fase consiste nel classificare le apparecchiature coinvolte nei percorsi di propagazione infunzione della loro capacità di causare o propagare un effetto domino. L’algoritmo dedicato inquesta fase è eseguito su VBA.I risultati ottenuti anche nell’applicazione ad un caso di studio hanno evidenziato le potenzialitàdel metodo, che rappresenta un significativo progresso nell’analisi quantitativa dell’effetto domino
Da, Silva Garcia Bruna. "Analyse des mécanismes d'interaction entre un bloc rocheux et un versant de propagation : application à l'ingénierie". Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAI062/document.
Texto completo da fonteNumerous uncertainties related to the machanical interaction between rock boulders and the natural slope during block falls persist; and the forecast of such events is therefore still uncertain. Nevertheless, digital tools and computing power are constantly evolving. Previously, trajectory calculations were restricted to simplified geometries and two-dimensional ballistic movements, but it is now possible to incorporate refinements such as the complex shape of the blocks, three-dimensional numerical models of terrain of large sizes, as well as a better accounting of the dissipative mechanisms at the point of impact between the block and the run-out slope.The main objective of this work is to analyze, with a discrete elements code in three dimensions, the influence of the shape and interaction parameters on the nature of the rebound in an engineering context. We first present a methodology for identifying and studying the sensitivity of contact parameters, developed and validated from laboratory experiments. This methodology was subsequently applied to two block fall experiments conducted on medium and large real-scale scenarios.The study conducted on a medium scale allowed the numerical model to be compared with data obtained during an experimental rockfall tests campaign commissioned by the SNCF and conducted in collaboration with IRSTEA in a railway. The analyzes that were carried out mainly focused on the impact velocities of the blocks with ballast and propagation distances.The large-scale study is based on a series of block releases performed at the experimental site (Authume quarry, France) as part of a Benchmark proposed inside the National Project C2ROP. The mainly goal of this Benchmark is to access and compare trajectory softwares, numerical computation codes and engineering practices to define their relevance and validity domains. As part of the thesis, this work was conducted in several phases (blind phase and then conducted taking in account partial data measured during the experimental tests) and we present the evolution of these analyzes at the end of each one of these phases. The study focused on the velocities, heights and energies of the blocks at certain points of the propagation profile, as well as on the stopping positions of the blocks. The influence of block shapes on run-out distances is also presented.Lastly, an internal Benchmark performed within the IMSRN company shows the importance, on the analyzes, of the expertise of the operator, and the consequences derived from the application of different trajectography tools (in 2D and in 3D). This work highlights the current issues that are often faced by engineering offices and engineers in charge of risk quantification
Boulanger, Rémi. "La prise de feu et la génération d'incendie en milieu pyrotechnique ; propagation dans un environnement à risques". Poitiers, 1999. http://www.theses.fr/1999POIT2290.
Texto completo da fonteKaya, Yildirim. "Simulation of wireless propagation and jamming in a high-rise building". Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Sep%5FKaya.pdf.
Texto completo da fonteDespontin-Monsarrat, Emmanuelle. "Aide à la décision pour la coopération inter-entreprises dans le cadre de la production à la commande". Phd thesis, Université Paul Sabatier - Toulouse III, 2004. http://tel.archives-ouvertes.fr/tel-00008466.
Texto completo da fonteRoullé, Agathe. "Etude du mouvement sismique dans la vallée de Mexico à partir d'un réseau accélérométrique 3D de faible ouverture dans la colonia Roma". Université Louis Pasteur (Strasbourg) (1971-2008), 2004. https://publication-theses.unistra.fr/public/theses_doctorat/2004/ROULLE_Agathe_2004.pdf.
Texto completo da fonteThe seismic motion in the lake-bed zone of Mexico City is affected by strong site effects due to the presence of a soft surficial clay layer. These site effects are, in particular, responsible for an important amplification of ground motion, which can reach a factor 50 for periods between 0. 3 and 1 Hz, between the lake-bed zone and the hill zone. We also can observe a large duration of strong ground motion in this area. Despite the installation of more than 100 new digital strong motion stations in Mexico City after 1985, only little progress have been done towards understanding the relation between the amplification of ground motion in the lake-bed zone and the large duration of seismic motion. In order to improve our comprehension of the observed wavefield in Mexico City, we have realized a systematic analysis of its characteristics from the records of a small aperture 3D array installed in 2001 in the colonia Roma, in the lake-bed zone of the city. In 2001, it has been decided to install 11 new accelerometers in the colonia Roma, a district located the lake-bed zone of the city, near an existing array operated by CENAPRED and known as "the Roma array". Together with the existing stations, these new instruments form a 3D array of small aperture (less than 1 km), with 15 surface and 6 borehole stations. Since its installation, this new array recorded the 10/08/2001 Coyuca event, Guerrero, (M=6. 1) and the 01/22/2003 Colima (M=7. 6) event. [. . . ]
Lhomme, Serge. "Les réseaux techniques comme vecteur de propagation des risques en milieu urbain - Une contribution théorique et pratique à l'analyse de la résilience urbaine". Phd thesis, Université Paris-Diderot - Paris VII, 2012. http://tel.archives-ouvertes.fr/tel-00772204.
Texto completo da fonteCarladous, Simon. "Approche intégrée d’aide à la décision basée sur la propagation de l’imperfection de l’information – application à l’efficacité des mesures de protection torrentielle". Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEM008/document.
Texto completo da fonteMany torrential protective check dams have been built in French mountainous areas since the 19th century. They aim to reduce risk in torrential watersheds. Analysis of their effectiveness is needed to assess residual risk and to choose the best maintenance strategy in a context of reduced budgets. Chapter I introduces main issues due both to definition of effectiveness concept and also the several criteria and system scales that have to be assessed. Moreover, required expertise is based on imperfect information, provided by several sources with different reliability levels. To help such decisions, this thesis proposes to break down general assessment into several smaller decision-making problems. In chapter II, dependability analysis tools and Evidential Reasoning based-decision-aiding methods (ER-DAMs), using fuzzy sets and possibility theories, are chosen to help individual decisions. Chapters III to V then introduce new developments. Effectiveness concept is first defined. A multi-scale dependability analysis helps to describe each decision-making problem. ER-DAMs are then adapted to help effectiveness assessment at each system’s scale. Technical improvements are provided to these methods for a better knowledge representation and final decision. Improved methods are then associated. Finally, individual problems and associated methods are integrated in a generic methodology to help torrential protective measures’ effectiveness assessment at watershed scale. The last chapter VI focuses on discussion of integrative aspects and of ER-DAMs’ specific developments. It gives some elements to improve methods but also to help operational implementation of the generic methodology
Davila, Sylvie. "Etude de l'influence de la virulence des souches de peste procine classique, sur les risques de propagation de la maladie. Etude de l'immunopathogénicité d'une souche moyennement virulente". Rennes 1, 2004. http://www.theses.fr/2004REN10096.
Texto completo da fonteJaber, Hadi. "Modeling and analysis of propagation risks in complex projects : application to the development of new vehicles". Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLC022/document.
Texto completo da fonteThe management of complex projects requires orchestrating the cooperation of hundreds of individuals from various companies, professions and backgrounds, working on thousands of activities, deliverables, and risks. As well, these numerous project elements are more and more interconnected, and no decision or action is independent. This growing complexity is one of the greatest challenges of project management and one of the causes for project failure in terms of cost overruns and time delays. For instance, in the automotive industry, increasing market orientation and growing complexity of automotive product has changed the management structure of the vehicle development projects from a hierarchical to a networked structure, including the manufacturer but also numerous suppliers. Dependencies between project elements increase risks, since problems in one element may propagate to other directly or indirectly dependent elements. Complexity generates a number of phenomena, positive or negative, isolated or in chains, local or global, that will more or less interfere with the convergence of the project towards its goals. The thesis aim is thus to reduce the risks associated with the complexity of the vehicle development projects by increasing the understanding of this complexity and the coordination of project actors. To do so, a first research question is to prioritize actions to mitigate complexity-related risks. Then, a second research question is to propose a way to organize and coordinate actors in order to cope efficiently with the previously identified complexity-related phenomena.The first question will be addressed by modeling project complexity and by analyzing complexity-related phenomena within the project, at two levels. First, a high-level factor-based descriptive modeling is proposed. It permits to measure and prioritize project areas where complexity may have the most impact. Second, a low-level graph-based modeling is proposed, based on the finer modeling of project elements and interdependencies. Contributions have been made on the complete modeling process, including the automation of some data-gathering steps, in order to increase performance and decrease effort and error risk. These two models can be used consequently; a first high-level measure can permit to focus on some areas of the project, where the low-level modeling will be applied, with a gain of global efficiency and impact. Based on these models, some contributions are made to anticipate potential behavior of the project. Topological and propagation analyses are proposed to detect and prioritize critical elements and critical interdependencies, while enlarging the sense of the polysemous word “critical."The second research question will be addressed by introducing a clustering methodology to propose groups of actors in new product development projects, especially for the actors involved in many deliverable-related interdependencies in different phases of the project life cycle. This permits to increase coordination between interdependent actors who are not always formally connected via the hierarchical structure of the project organization. This allows the project organization to be actually closer to what a networked structure should be. The automotive-based industrial application has shown promising results for the contributions to both research questions. Finally, the proposed methodology is discussed in terms of genericity and seems to be applicable to a wide set of complex projects for decision support
Amitrano, Davide. "Emission acoustique des roches et endommagement : approches experimentale et numerique, application a la sismicite miniere". Grenoble 1, 1999. http://www.theses.fr/1999GRE10002.
Texto completo da fonteBazzoli, Sébastien. "Caractérisation et simulation de la susceptibilité des circuits intégrés face aux risques d'inductions engendrées par des micro-ondes de forte puissance". Lille 1, 2005. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2005/50376-2005-Bazzoli.pdf.
Texto completo da fonteMeyer, Arnd, e Peter Steinhorst. "Modellierung und Numerik wachsender Risse bei piezoelektrischem Material". Universitätsbibliothek Chemnitz, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-61981.
Texto completo da fonteWoesteland, Alexandre. "Contribution à l'étude de la propagation d'ondes électromagnétiques utilisées dans un système de localisation pour les transports guides : étude des risques de couplage entre voies à différentes fréquences". Lille 1, 1994. http://www.theses.fr/1994LIL10102.
Texto completo da fonteDutozia, Jérôme. "Espaces à enjeux et effets de réseaux dans les systèmes de risques". Phd thesis, Université Nice Sophia Antipolis, 2013. http://tel.archives-ouvertes.fr/tel-00785772.
Texto completo da fonteToe, David. "Etude de l’influence des peuplements forestiers de type taillis sur la propagation des blocs rocheux". Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAU023/document.
Texto completo da fonteThis research work is dedicated to improve the integration of coppice stands in rockfall analyses.First, a model was built to create virtual coppice stands. This model was validated using field inventories in coppice stands.Two numerical models were developed to simulate impacts of blocks on single trees and coppice stools using the Discrete Elements Method (MED).These models were calibrated using laboratory impact tests on beech stems.They account for the influence of the root system and of the crown on the tree dynamic response, the explicit modeling of the contact between the block and the impacted stem and the non-linearity evolution into the trunk during impact.Finally, a DEM rockfall software was developed to model rockfall propagation in coppice stands.The protective role against rockfall hazard of different coppice stands was characterized with this model
Coudoro, Kodjo. "Etude expérimentale et modélisation de la propagation de flammes en milieu confiné et semi confiné". Thesis, Orléans, 2012. http://www.theses.fr/2012ORLE2005.
Texto completo da fonteThe context of the current study is the assessment of the occurrence of flame acceleration in accidental situations. The methodology developed for the assessment of hydrogen hazard in the nuclear industry led to the definition of a criterion for the prediction of the acceleration potential of a hydrogen/air/dilutant mixture based on its properties. This study aims to extend this methodology to gaseous mixtures that can be encountered in the classical industry. Therefore, three mixtures were chosen: the first two are representatives of a natural gas/air mixture: G27 (82%CH4/18%N2) and G222 (77%CH4/23%H2). The third one is a H2/CO (50%H2/50%CO) mixture and represents the Syngas. During this work, flammability limits were measured at 300 K and two initial pressures (1 and 2 bar) for each mixture. Fundamental flame speeds and Markstein lengths were also measured at three initial temperatures (300, 330, 360 K) and 2 initial pressures (1 and 2 bar) for each mixtures. A kinetic modeling was performed based on three detailed kinetic models and allowed the calculation of the global activation energy on the basis of the kinetic model which showed the best agreement with the experimental data. The acceleration potential for each mixture in presence of obstacles has then been investigated. It was found that different criteria were to be applied depending on whether the flame is stable or not. A predicting criterion was proposed in both case
Picot, Alexis. "2P optogenetics : simulation and modeling for optimized thermal dissipation and current integration Temperature rise under two-photon optogenetics brain stimulation". Thesis, Sorbonne Paris Cité, 2018. http://www.theses.fr/2018USPCB227.
Texto completo da fonteOver the past fifteen years, optogenetics has revolutionized neuroscience research by enabling control of neuronal circuits. The recent development of several illumination approaches, combined with new photosensitive proteins, opsins, have paved the way to neuronal control with the single-cell precision. The new ambition to use these approaches in order to activate tens, hundreds, thousands of cells in vivo has raised many questions, in particular concerning the possible photoinduced damages and the optimization of the choice of the illumination / opsin couple. During my PhD, I developed an experimentally verified simulation that calculates, under all actual illumination protocols, what will be the temperature rise in the brain tissue due to the absorption of light. In parallel, I modeled, from electrophysiology recordings, the intracellular currents observed during these photostimulations, for three different opsins, allowing me to simulate them. These models will allow the researchers to optimize their illumination protocols to keep heating as low as possible in the sample, while helping to generate optimized photocurrent dynamics according to experimental requirements
Mühle, Volker. "Theoretische und numerische Untersuchungen zu morphologischen Übergängen beim Rißwachstum". Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2000. http://nbn-resolving.de/urn:nbn:de:swb:14-993117114171-16728.
Texto completo da fonteThis paper investigates the formation of crack patterns in stationary and transient temperature fields analytically with linear elastic fracture mechanics and numerically with the finite elements method (FEM). In particular, we consider the experimental situation of a narrow thin strip of hot glass slowly lowered into cold water, with temperature difference and velocity as variable parameters. The parameter regions of no crack, one straight crack and one oscillating crack are determined. The type of phase transition related to the borderline between straight and oscillating crack is characterized. The theoretical results are compared with those of other authors. Similar investigations and comparisions are done for the propagation of multiple cracks. Quenching of a wide thin strip leads to a hierarchy of cracks whose scaling properties are analyzed. Without any fitting, theory and experiment agree surprisingly well
Mühle, Volker. "Theoretische und numerische Untersuchungen zu morphologischen Übergängen beim Rißwachstum". Doctoral thesis, Technische Universität Dresden, 1999. https://tud.qucosa.de/id/qucosa%3A24726.
Texto completo da fonteThis paper investigates the formation of crack patterns in stationary and transient temperature fields analytically with linear elastic fracture mechanics and numerically with the finite elements method (FEM). In particular, we consider the experimental situation of a narrow thin strip of hot glass slowly lowered into cold water, with temperature difference and velocity as variable parameters. The parameter regions of no crack, one straight crack and one oscillating crack are determined. The type of phase transition related to the borderline between straight and oscillating crack is characterized. The theoretical results are compared with those of other authors. Similar investigations and comparisions are done for the propagation of multiple cracks. Quenching of a wide thin strip leads to a hierarchy of cracks whose scaling properties are analyzed. Without any fitting, theory and experiment agree surprisingly well.
Nekkab, Narimane. "Spread of hospital-acquired infections and emerging multidrug resistant enterobacteriaceae in healthcare networks : assessment of the role of interfacility patient transfers on infection risks and control measures". Thesis, Paris, CNAM, 2018. http://www.theses.fr/2018CNAM1180/document.
Texto completo da fonteLa propagation des infections nosocomiales (IN), notamment liées aux bactéries multi-résistantes, au sein du réseau des hôpitaux, est un grand enjeu de santé publique. L’évaluation du rôle joué par les transferts inter-établissements des patients sur cette propagation pourrait permettre l’élaboration de nouvelles mesures de contrôle. L’identification de nouvelles mesures de contrôle est particulièrement importante pour les bactéries résistantes aux antibiotiques comme les entérobactéries productrices de carbapenemase (EPC) pour lesquelles les possibilités de traitement sont très limitées. L’utilisation des données de réseaux de contact inter-individus et de transferts inter-établissement dans la modélisation mathématique ont rendu ces modèles plus proches de la réalité. Toutefois, ces derniers restent limités à quelques milieux hospitaliers et quelques pathogènes. La thèse a eu pour objectifs de 1) mieux comprendre la structure des réseaux hospitaliers français et leur impact sur la propagation des IN ; et 2) évaluer le rôle des transferts sur la propagation des EPC.Les réseaux hospitaliers français sont caractérisés par des flux de patients vers des hubs et par deux niveaux de communautés des hôpitaux. La structure du réseau de transfert des patients présentant une IN n’est pas différente de celle du réseau général de transfert des patients. Au cours des dernières années, le nombre d’épisode d’EPC a augmenté en France et les prédictions prévoient une poursuite de cette augmentation, avec des pics de saisonnalité en octobre. Ce travail a également montré que, depuis 2012, les transferts de patients jouent avec les années un rôle de plus en plus important sur la diffusion des EPC en France. Des évènements de propagation multiple liée aux transferts sont également de plus en plus souvent observés.En conséquence, la structure du réseau des hôpitaux pourrait servir de base pour la proposition des nouvelles stratégies de contrôles des IN en général, et des EPC en particulier. Les hôpitaux très connectés des grandes métropoles et les flux des patients entre les communautés locale et régionale doivent être considérés pour le développement de mesures de contrôle coordonnées entre établissements de santé
Bzduch, Pavel. "Využití počítačové grafiky v silnoproudé elektrotechnice". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-217593.
Texto completo da fonteNefzi, Amani. "Analysis and dosimetry of the coupling of electromagnetic waves with biological tissues : application to applicator design for biomedical and study of health effects". Thesis, Limoges, 2021. http://www.theses.fr/2021LIMO0011.
Texto completo da fonteThe evolution and increasing use of mobile communications systems was associated with laboratory investigations to study radiofrequency electromagnetic waves exposure safety. In this context, this thesis focuses on the characterization of exposure systems allowinglaboratory in vitro studies on cell models. A dual numerical and experimental approach is implemented to perform the devices dosimetry allowing to determine and control the exposure levels. One of the limitations associated with this dosimetry is due to the micrometric dimensions involved. Therefore, a microscopy technique based on a temperature-dependent fluorescent dye named Rhodamine B was set up and evaluated. This assessment recommends an optimal concentration of the dye at around 50 μM. After calibration, it is possible to estimate the specific absorption rate (SAR) from the temperature variation, even for low levels of SAR (< W / kg) with a spatial resolution of less than ten micrometers i.e. microdosimetry. The two main exposure systems studied, based on microelectrode arrays (MEA), allow the recording of neurons electrophysiological activity. Exposure to electromagnetic waves is achieved simultaneously by inserting these MEAs into TEM cells exposure systems. Dosimetry carried out at 1.8 GHz shows a higher sensitivity of one MEA to its environment. It was shown that the modifications made to the second MEA such as its aperture size and ground planes, have reduced the proximity environment influence. The microdosimetry demonstrated good homogeneity of the SAR between the electrodes with an estimated value of 7 ± 1 W / kgfor 1 W incident power. Finally, a microfluidic exposure device based on a coplanar waveguide was characterized under static conditions
Deobarro, Mikaël. "Etude de l'immunité des circuits intégrés face aux agressions électromagnétiques : proposition d'une méthode de prédiction des couplages des perturbations en mode conduit". Thesis, Toulouse, INSA, 2011. http://www.theses.fr/2011ISAT0002/document.
Texto completo da fonteWith technological advances in recent decades, the complexity and operating speeds of integrated circuits have greatly increased. While these developments have reduced dimensions and supply voltages of circuits, electromagnetic compatibility (EMC) of components has been highly degraded. Identified as a technological lock, EMC is now one of the main causes of circuits re-designs because issues related to generating and coupling noise mechanisms are not sufficiently studied during their design. This manuscript introduces a methodology to study propagation of electromagnetic disturbances through integrated circuits by measurements and simulations. To improve our knowledge about propagation of electromagnetic interferences (EMI) and coupling mechanisms through integrated circuits, we designed a test vehicle developed in the SMOS8MV® 0.25µm technology from Freescale Semiconductor. In this circuit, several basic functions such as I/O bus and digital blocks have been implemented. Asynchronous on-chip voltage sensors have also been integrated on different supplies of the chip to analyze propagation of disturbances injected on supply pins and wires of the component (DPI and BCI injection). In addition, we propose various tools to facilitate modeling and simulations of Integrated Circuit’s immunity (PCB model extraction, injection systems modeling approaches, innovative method to predict and correlate levels of voltage / power injected during conducted immunity measurements, modeling flow). Each tool and modeling method proposed is evaluated on different test cases. To assess our modeling approach, we finally apply it on a digital block of our test vehicle and compare simulation results to various internal and external measurements performed on the circuit
Hessas, Nassima. "Evaluation cartographique et évolution diachronique par télédétection du risque incendie de forêt. Simulation de la propagation du feu dans le bassin versant du Paillon, Nice, Alpes-Maritimes". Phd thesis, 2005. http://tel.archives-ouvertes.fr/tel-00142644.
Texto completo da fonteGENTILI, FILIPPO. "Multi-physics modelling for the safety assessment of complex structural systems under fire. The case of high-rise buildings". Doctoral thesis, 2013. http://hdl.handle.net/11573/918045.
Texto completo da fonte