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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
591

淮南子呂氏春秋戰國策三書高誘注斠證. / "Huainan zi", "Lü shi chun qiu", "Zhan guo ce" san shu Gao You "zhu" jiao zheng.

January 1995 (has links)
作者何志華. / 書名原題 : 《淮南子》、《呂氏春秋》、《戰國策》三書高誘《注》斠證. / 論文(博士) -- 香港中文大學硏究院中國語言及文學學部, 1995. / 參考文献 : leaves 399-406. / zuo zhe He Zhihua. / Chapter 第一章 --- 高《注》釋例 --- p.1 / Chapter 1 --- 循文立訓例 --- p.1 / Chapter 1.1 --- 訓解單字例 --- p.1 / Chapter 1.2 --- 訓解兩字詞語例 --- p.5 / Chapter 1.3 --- 訓解多字例 --- p.7 / Chapter 2 --- 稱引師說例 --- p.8 / Chapter 2.1 --- 高誘稱引師說例 --- p.8 / Chapter 2.2 --- 高誘不采師說例 --- p.13 / Chapter 3 --- 互文例 --- p.15 / Chapter 4 --- 闕疑例 --- p.17 / Chapter 4.1 --- 音律 --- p.18 / Chapter 4.2 --- 地理 --- p.18 / Chapter 4.3 --- 時令 --- p.21 / Chapter 4.4 --- 夸誕之說 --- p.22 / Chapter 4.5 --- 鳥獸 --- p.23 / Chapter 4.6 --- 古人姓名事跡 --- p.24 / Chapter 4.7 --- 與書傳所記不合者 --- p.24 / Chapter 4.8 --- 文義未明者 --- p.25 / Chapter 5 --- 高誘聲訓例 --- p.26 / Chapter 5.1 --- 擬音例 --- p.27 / Chapter 5.1.1 --- 讀如 --- p.27 / Chapter 5.1.2 --- 讀若 --- p.28 / Chapter 5.1.3 --- 讀近 --- p.29 / Chapter 5.1.4 --- 讀似 --- p.30 / Chapter 5.1.5 --- 讀與「某」同 --- p.30 / Chapter 5.2 --- 改讀例 --- p.31 / Chapter 5.2.1 --- 據字書訓詁 --- p.33 / Chapter 5.2.1.1 --- 《爾雅》 --- p.33 / Chapter 5.2.2 --- 據傳注舊詁 --- p.34 / Chapter 5.2.2.1 --- 毛《傳》 --- p.34 / Chapter 5.2.2.2 --- 《毛詩》鄭《箋》 --- p.34 / Chapter 5.2.2.3 --- 《周禮》鄭《注》 --- p.35 / Chapter 5.2.3 --- 別書重文 --- p.35 / Chapter 5.3 --- 改字例 --- p.36 / Chapter 5.4 --- 附論:《淮南子》高《注》音讀斠證 --- p.40 / Chapter 6 --- 考文例 --- p.50 / Chapter 第二章 --- 《淮南子》、《呂氏春秋》、《戰國策》三書高《注》引斠證 --- p.57 / Chapter 1 --- 高誘據《文子》爲《注》證 --- p.57 / Chapter 1.1 --- 《文子》因襲《淮南》證 --- p.57 / Chapter 1.2 --- 古人據重文爲注證 --- p.61 / Chapter 1.3 --- 高《注》與《文子》重文相合例 --- p.64 / Chapter 1.4 --- 高《注》與《文子》重文不合例 --- p.71 / Chapter 1.5 --- 結語 --- p.74 / Chapter 1.6 --- 附論 --- p.76 / Chapter 1.6.1 --- 附論一:《淮南子》高誘《注》雖與《文子》相同而非出於 《文子》例 --- p.76 / Chapter 1.6.2 --- 附論二 --- p.81 / Chapter 2 --- 高誘引《老子》考 --- p.82 / Chapter 3 --- 高誘引《莊子》考 --- p.85 / Chapter 4 --- 高誘引《淮南子》考 --- p.89 / Chapter 5 --- 高誘引《呂氏春秋》考 --- p.107 / Chapter 6 --- 高誘引《戰國策》考 --- p.108 / Chapter 7 --- 高誘引《周易》考 --- p.110 / Chapter 8 --- 高誘引¯《‘ة書》考 --- p.113 / Chapter 9 --- 高誘引《逸周書》考 --- p.118 / Chapter 10 --- 高誘用《詩》考 --- p.118 / Chapter 11 --- 高誘引《周禮》考 --- p.151 / Chapter 12 --- 高誘引《禮記》考 --- p.166 / Chapter 13 --- 高誘引《春秋經》考 --- p.172 / Chapter 14 --- 高誘引《春秋左傳》考 --- p.173 / Chapter 15 --- 高誘引《國語》考 --- p.208 / Chapter 16 --- 高誘引《公羊傳》考 --- p.216 / Chapter 17 --- 高誘本《穀梁傳》爲《注》考 --- p.219 / Chapter 18 --- 高誘引《史記》考 --- p.220 / Chapter 19 --- 高誘引《漢書》考 --- p.221 / Chapter 20 --- 高誘引《山海經》考 --- p.224 / Chapter 21 --- 高誘引《論語》考 --- p.230 / Chapter 22 --- 高誘引《孟子》考 --- p.243 / Chapter 23 --- 高誘引《孝經》考 --- p.251 / Chapter 24 --- 高誘據《爾雅》爲訓詁證 --- p.253 / Chapter 25 --- 高誘據毛《傳》爲訓詁證 --- p.271 / Chapter 26 --- 高誘引兵書考 --- p.278 / Chapter 26.1 --- 《孫子》 --- p.278 / Chapter 26.2 --- 《司馬法》 --- p.279 / Chapter 26.3 --- 《尉繚子》 --- p.279 / Chapter 27 --- 高誘引《說苑》考 --- p.280 / Chapter 28 --- 高誘引《楚辭》考 --- p.281 / Chapter 29 --- 高誘引《世本》考 --- p.282 / Chapter 30 --- 高誘引緯書考 --- p.282 / Chapter 30.1 --- 《河圖括地象》 --- p.282 / Chapter 30.2 --- ¯《‘ة書五行傳》 --- p.283 / Chapter 30.3 --- 《洪範五行傳》 --- p.284 / Chapter 第三章 --- 《淮南子》、《呂氏春秋》、《戰國策》三書高《注》互異集證 --- p.287 / Chapter 第四章 --- 《淮南子》、《呂氏春秋》、《戰國策》三書高《注》斠證 --- p.307 / 徵引書目 --- p.399-406
592

Reducing the cost of heuristic generation with machine learning

Ogilvie, William Fraser January 2018 (has links)
The space of compile-time transformations and or run-time options which can improve the performance of a given code is usually so large as to be virtually impossible to search in any practical time-frame. Thus, heuristics are leveraged which can suggest good but not necessarily best configurations. Unfortunately, since such heuristics are tightly coupled to processor architecture performance is not portable; heuristics must be tuned, traditionally manually, for each device in turn. This is extremely laborious and the result is often outdated heuristics and less effective optimisation. Ideally, to keep up with changes in hardware and run-time environments a fast and automated method to generate heuristics is needed. Recent works have shown that machine learning can be used to produce mathematical models or rules in their place, which is automated but not necessarily fast. This thesis proposes the use of active machine learning, sequential analysis, and active feature acquisition to accelerate the training process in an automatic way, thereby tackling this timely and substantive issue. First, a demonstration of the efficiency of active learning over the previously standard supervised machine learning technique is presented in the form of an ensemble algorithm. This algorithm learns a model capable of predicting the best processing device in a heterogeneous system to use per workload size, per kernel. Active machine learning is a methodology which is sensitive to the cost of training; specifically, it is able to reduce the time taken to construct a model by predicting how much is expected to be learnt from each new training instance and then only choosing to learn from those most profitable examples. The exemplar heuristic is constructed on average 4x faster than a baseline approach, whilst maintaining comparable quality. Next, a combination of active learning and sequential analysis is presented which reduces both the number of samples per training example as well as the number of training examples overall. This allows for the creation of models based on noisy information, sacrificing accuracy per training instance for speed, without having a significant affect on the quality of the final product. In particular, the runtime of high-performance compute kernels is predicted from code transformations one may want to apply using a heuristic which was generated up to 26x faster than with active learning alone. Finally, preliminary work demonstrates that an automated system can be created which optimises both the number of training examples as well as which features to select during training to further substantially accelerate learning, in cases where each feature value that is revealed comes at some cost.
593

Modélisation du zooplancton et du micronecton marins / Modeling marine zooplankton and micronekton

Conchon, Anna 20 June 2016 (has links)
Le zooplancton et le micronecton sont les deux premiers échelons animaux de la chaine trophique marine. Bien que de tailles très différentes (200μm à 2mm pour le zooplancton, 2 à 20cm pour le micronecton), ces deux groupes d'espèces variées partagent un comportement singulier : les migrations nycthémérales. Ces migrations journalières entre la profondeur de jour et la surface de nuit induisent des flux de matière organique très importants entre les différentes profondeurs de l'océan. L'étude des cycles biogéochimiques océaniques a une grande importance pour l'étude du changement climatique. Cette étude est notamment conduite à travers le développement de modèles globaux de circulation océanique et de biogéochimie. La suite logique de ces développements est donc la modélisation du zooplancton et du micronecton. La gamme de modèles SEAPODYM modélise avec parcimonie la chaine trophique depuis le zooplancton jusqu'aux prédateurs supérieurs à l'aide de trois modèles. Cette thèse présente le modèle de biomasse de zooplancton SEAPODYM-LTL (pour lower trophic level, niveau trophique bas), ainsi qu'une analyse de sa sensibilité aux forçages. En effet, la particularité de ces modèles est leur forçage offline par des champs de courants, température et production primaire produits par d'autres modèles. Le modèle SEAPODYM-LTL est également comparé au modèle PISCES (NPZD), et présente des performances similaires à ce dernier dans le cas testé. Afin d'améliorer les prédictions du modèle SEAPODYM-MTL (mid-trophic level, i.e. le modèle de biomasse de micronecton), une méthodologie d'assimilation de données a été mise en place pour affiner la paramétrisation utilisée. Des données d'acoustique active (38kHz) sont donc utilisées pour enrichir le modèle. Cette méthodologie a été conçue autour d'un cas test présenté dans cette thèse. L'extension du jeu de données acoustiques assimilées au modèle a permis de mettre en évidence le besoin de mieux modéliser les profondeurs des couches verticales de SEAPODYM. Cela a été réalisé à l'aide du jeu de données acoustiques évoqué précédemment. Cette étude est également présentée dans cette thèse. / Zooplankton and micronecton are the first marine trophic levels. Different by their size (200μm to 2mm for zooplankton, 2 to 20cm for micronekton), this two groups undergo diel vertical migration from depth by day to the surface during the night. These migrations create major organic matter fluxes between the deep ocean and the surface. Biogeochemical cycles are of great importance for climate change studies. These studies are conducted with ocean global circulation model and biogeochemical model. The way to go is develop low and mid-trophic level modelling approaches. SEAPODYM ensemble of models are three parsimonious model of biomass at diverse level of the trophic chain, from zooplankton to top predators. This thesis introduce the zooplankton biomass model SEAPODYM-LTL (lower trophic level) and a forcing fields sensitivity analysis. Indeed, these model are forced off line by currents, temperature and primary production fields produced by other models. SEAPODYM-LTL has also been compared to PISCES (NPZD) and both have similar performance score in this study. In order to improve SEAPODYM-MTL (mid trophic level) predictions, a data assimilation framework has been developed to find a better parameterisation. 38kHz active acoustic data have been used to improve the model. This methodology has been develop thanks to a test case that we present in this thesis. The gathered acoustic dataset permitted to show the need of a better definition of vertical layer depths. It has been developed using the acoustic dataset. The related study is presented in this thesis.
594

Le couplage intersismique et les glissements lents vus par la géodésie spatiale : applications à la subduction mexicaine et à la faille décrochante nord anatolienne / Interseismic coupling and slow slip events seen by space geodesy : application to the Mexican subduction zone and the North Anatolian strike-slip fault

Rousset, Baptiste 22 November 2016 (has links)
L'avènement de la géodésie spatiale ces dernières décennies a permis la découverte de la diversité des modes de glissement sur les failles. Dans cette thèse, nous nous intéressons au glissement asismique à la fois en contexte de subduction et en contexte décrochant. Nous étudions l'ensemble de la subduction mexicaine au niveau des régions de Guerrero et Oaxaca, où plusieurs séismes lents ont été répertoriés, ainsi que le segment en glissement asismique d'Ismetpasa le long de la faille décrochante Nord-Anatolienne en Turquie. La carte de couplage (estimé entre les grands séismes lents) entre les plaques Cocos et Nord Américaine indique un couplage élevé et relativement homogène en base de zone sismogénique. Cependant, des variations latérales de couplage importantes sont remarquables dans la zone sismogénique. En particulier, une zone de fort couplage à Oaxaca est localisée à l'emplacement de la rupture sismique de 1978 et a accumulé un déficit de glissement de 5 cm en 9 ans. Ces variations latérales de couplage sont corrélées avec les distances fosse-côte et des zones à l'état critiques sont localisées aux transitions entre faible et fort couplage. Ces observations suggèrent une pérennité au long-terme des motifs spatiaux de couplage. Nous proposons un mécanisme de déformation durant la phase co-sismique, basé sur l'existence de transitions frictionnelles sur le plan de subduction, qui permet de réconcilier les vitesses intersismiques mesurées sur quelques décennies et la morphologie long-terme. Ces vitesses intersismiques sont généralement considérées comme constantes sur plusieurs années. Cependant, une analyse plus fine montre une riche dynamique temporelle, avec en particulier la présence d'évènements transitoires finis de magnitudes et durées variables. Nous avons suivi deux approches afin de détecter et caractériser des glissements transitoires dans nos deux zones d'étude. (i) L'analyse d'un réseau dense d'interférogrammes, obtenus à partir de données InSAR des satellites CosmoSky-Med sur le segment de faille d'Ismetpasa, a permis de détecter un évènement de glissement transitoire d'un mois. Enregistré en Novembre 2013, aucun autre glissement n'a été détecté durant les 9 autres mois de l'analyse. Cet évènement d'une magnitude de 5.2 à 5.5 a relâché une énergie équivalant à 1,5 à 2 ans de glissement asismique continu à la vitesse moyenne précédemment estimée. Cette découverte remet en question le modèle mécanique de glissement de ce segment. (ii) Le développement d'une méthode de corrélation entre des évènements de glissements synthétiques et des séries temporelles GPS préalablement traitées permet la détection de glissements transitoires d'amplitude équivalente à celle du bruit. Appliquée à un jeu de données synthétiques sur la subduction mexicaine, cette méthode montre que l'on peut caractériser avec précision des évènements de Mw > 6. Appliquée à des données réelles au niveau de la lacune sismique de Guerrero entre Février 2005 et Mai 2007, cette méthode a permis de détecter 15 nouveaux événements transitoires. Ces évènements coïncident temporellement avec de fortes activités de trémors et LFEs et sont localisés aux pourtours du séisme lent de Mw 7.5 de 2006. Ces détections permettent de mieux contraindre la loi d'échelle des glissements lents et d'éclairer la dynamique spatiale et temporelles des évènements transitoires en base de zone sismogénique. / The development of space geodesy during the last decades has led to the discovery of the slip modes diversity on faults. In this thesis, we focus on aseismic slip on both subduction zones and continental strike slip faults. We study the subduction zone of Mexico, from Guerrero to Oaxaca regions, where large Slow Slip Events have been recorded, as well as the Ismetpasa creeping fault segment of the North Anatolian Fault in Turkey. The map of interplate coupling (in between large slow slip events) estimated between the Cocos and North America plates in Mexico shows a relatively high coupling coefficient, laterally homogeneous at the base of the seismogenic zone. Strong lateral coupling variations are notable within the seismogenic zone. A high coupling pattern in Oaxaca is located in the same area as the 1978 seismic rupture and has accumulated 5 cm of slip deficit in 9 years. Those lateral coupling variations are correlated with trench-coast distances. We show that critical state areas are located at the transitions between low and high coupling zones. These observations suggest a persistency of the coupling patterns over geological time scales. We propose a mechanism of deformation during the coseismic phase, related to the existence of frictional transitions on the subduction plane, that allows to reconcile decadal observations of interseismic velocities with the long term building of the coastal morphology. The interseismic velocities are generally considered to be constant over a few years. However, refined temporal analysis show the richness of their temporal dynamics, with evidences of slow slip events of various magnitudes and durations. We follow two different approaches to detect and characterize small amplitude slow slip events in our two study areas. (i) The dense network of interferograms with short repeat times acquired by the CosmoSky-Med constellation along the Ismetpasa fault segment allows to detect a month-long transient slip event. During the 9 other months of the analysis, no clear aseismic slip signal has been observed. With a Mw 5.2 - 5.5, this transient event has released an energy equivalent to the one that would be released during 1.5 - 2 years at the average creep rate estimated by previous studies. This discovery forces us to reconsider the mechanical model in place for this segment. (ii) The development of a correlation methodology between synthetic transient slip events and post-processed GPS time series allows to detect transient events with amplitude close to the GPS background noise. Applied to a synthetic dataset over the Mexican subduction zone, we show that this method is able to precisely detect and characterize Mw>6 events. Applied to real data between February 2005 and May 2007 in the Guerrero gap area, our new GPS-matched filter allows to detect 15 new events. Those events are temporally correlated with bursts of tremors and LFEs activity and are surrounding the Mw 7.5 2006 SSE. These detections enable to better characterise the slow slip events scaling law and shed a new light on the spatial interaction of slow slip events at the base of the seismogenic zone.
595

Time but no space : resolving the structure and dynamics of active galactic nuclei using time domain astronomy

Starkey, David Andrew January 2017 (has links)
This thesis presents a study of the sub-light year regions of Active Galactic Nuclei (AGN). These environments contain accretion discs that orbit a central super-massive black hole. The luminosity of the AGN inner regions varies over time across all wavelengths with variability at longer wavelengths lagging behind that at shorter wavelengths. Since the AGN themselves are too remote and too compact to resolve directly, I exploit these time lags to infer the physical characteristics of the accretion disc and surrounding gas clouds that emit broad emission lines. These characteristics include the inclination and temperature profile of the accretion disc, and the shape (or light curve) of the luminosity fluctuations that drive the accretion disc variability. This thesis details the work in the first author papers of Starkey et al. (2016, 2017), in which I detail the statistical code, CREAM (Continuum REverberting AGN Markov Chain Monte Carlo), that I developed to analyse AGN accretion disc variability. I apply the code to a set of AGN light curve observations of the Seyfert 1 galaxy NGC 5548 by the AGN STORM collaboration (De Rosa et al., 2015; Edelson et al., 2015; Fausnaugh et al., 2016a; Goad et al., 2016; Starkey et al., 2017). I also present work detailing my variability analysis of the Seyfert galaxies NGC 6814, NGC 2617, MCG 08-11-11 and NGC 4151. This work has contributed to the analysis presented in (Troyer et al. 2016, Fausnaugh et al. submitted). I also investigate the implications of a twin accretion disc structure (Nealon et al., 2015) on the disc time lag measurements across near UV and optical wavelengths. I finish by detailing a modification to CREAM that allows it to merge continuum light curves observed in a common filter, but taken by multiple telescopes with different calibration and instrumental effects to consider.
596

The effects of experiential learning: An examination of three styles of experiential education programs and their implications for conventional classrooms

Pizarchik, Mary 01 January 2007 (has links)
Using methodologies of interviews and observation, this study focuses on three distinctive and successful kinds of experiential education: a summer arts program, an outdoor science program and a wilderness education program. The project applies insights from the programs to the central question of this thesis: How can experiential learning be utilized within the traditional classroom given the constraints of the No Child Left Behind Law and standardized teaching?
597

Brain-inspired predictive control of robotic sensorimotor systems / Contrôle prédictif neuro-inspiré de systèmes robotiques sensori-moteurs

Lopez, Léo 05 July 2017 (has links)
Résumé indisponible. / Résumé indisponible.
598

Active Cellular Nematics / Nématiques cellulaires actifs

Duclos, Guillaume 15 December 2015 (has links)
Des cellules allongées et apolaires cultivées à confluence s'alignent les unes avec les autres. Dans cette thèse, nous utilisons des concepts de la théorie de la matière active ainsi que de la physique des cristaux liquides afin d'étudier quantitativement l'émergence de cet ordre mésoscopique nématique pour des monocouches de cellules à deux dimension, avec et sans confinement. Il a été montré que les défauts topologiques jouent un rôle crucial durant l'auto-organisation de systèmes biologiques actifs. Ici, nous étudions la dynamique de ces défauts qui se forment dans le tissu nématique contractile. Étant intrinsèquement hors équilibre à cause de la consommation d'énergie par les cellules, la monocouche est parcourue par de complexes courants de cellules due à la migration spontanée des défauts et leur annihilation avec des défauts de charges opposées. En comparant nos résultats expérimentaux avec un modèle théorique, nous montrons que l'auto-organisation de la monocouche est liée à la minimisation de l'énergie de courbure du tissu. / Elongated, weakly interacting, apolar cells cultured at confluence align together, forming large domains where they are perfectly ordered. Using concepts from the active matter theory and the physics of liquid crystals, we study the emergence of this mesoscopic nematic order by quantifying the ordering dynamics in two-dimensional infinite monolayers or under confinement. Topological defects have been found to play a crucial role in the self-organization of active biological systems. We study the dynamics of the disclinations that form in these cellular contractile nematics. Being driven out of equilibrium by the consumption of energy by individual cells, the monolayer exhibits complex flow patterns as defects migrate spontaneously and annihilate pairwise. By comparing our experimental results to a nematic drop model, we show that the self-organization of the cellular nematic layer with no boundary conditions or under circular confinement is dictated by the minimization of the splay and bend distortions of the tissue.
599

Déformation active intraplaque : étude pluridisciplinaire terre-mer du risque sismique en Vendée, à partir du séisme du Marais Breton de 1799 (M6) / Intraplate active deformation : multi-disciplinary onshore-offshore analysis of seismic risk in Vendee (France), from the M6 1799 Vendée earthquake

Kaub, Caroline 15 March 2019 (has links)
Le département de la Vendée est classé en zone de risque sismique niveau 3, en raison d’une activité sismique continue et d’une sismicité historique de forte intensité avec l’évènement majeur du 25 janvier 1799 (M6) dans le Marais Breton. Ce séisme a provoqué des dégâts massifs localement à Bouin et dans la région nantaise, et a été largement ressenti dans l’Ouest de la France. La Vendée littorale est située sur la côte atlantique française au sud du cisaillement sud-armoricain. Elle est caractérisée par de nombreuses structures héritées d’origine varisque et d’orientation NW-SE, réactivées au Mésozoïque et au Cénozoïque délimitant des marais côtiers holocènes. L’enjeu de cette thèse est de caractériser la géométrie des éventuelles failles plio-quaternaires et potentiellement actives dans cette région, en s’intéressant particulièrement à la faille de Machecoul, bordière des bassins sédimentaires du Marais Breton et de la Baie de Bourgneuf et candidate potentielle pour le séisme Vendéen de 1799. Notre approche est pluridisciplinaire terre-mer, intégrant sismologie (réseau temporaire), géophysique marine (sismique réflexion Chirp et Sparker, bathymétrie haute résolution), morpho-tectonique, gravimétrie, étude de forages et sismicité historique. Notre étude a permis d’analyser et de caractériser (1) la structure et la géométrie en profondeur du système de failles normales de Machecoul, (2) la localisation des dépocentres plioquaternaires du Marais Breton et de la Baie de Bourgneuf en relation avec le système de failles de Machecoul, atteignant localement une vingtaine de mètres d’épaisseur, (3) la perturbation du réseau hydrographique et l’incision récente du relief du compartiment inférieur de la faille de Machecoul, probablement d’âge pliocène, ainsi que (4) l’activité microsismique de la faille de Machecoul. Nos données suggèrent que la sédimentation plioquaternaire des bassins en mer comme à terre au sud de la faille de Machecoul a pu être contrôlée par cette faille probablement héritée de l’Eocène. Ce travail confirme l’intérêt multi-disciplinaire de l’étude des failles en domaine de déformation faible et apporte un faisceau d’indices permettant de relier la faille de Machecoul à la rupture du séisme Vendéen de 1799 (M6), évènement historique de référence dans l’Ouest de la France de par son ampleur, et par là même de ses conséquences dans une zone littorale de plus en plus peuplée. / The Vendée department is classified as a level 3 seismic risk zone because of a moderate background seismic activity and a strong historical seismicity dominated by the 1799 January 25th (M6) major event in the MaraisBreton. This earthquake caused local massive damages in Bouin and around Nantes, and its perception area stretched widely in the West of France. Coastal Vendée is located on the French Atlantic coast, south of the SouthArmorican Shear Zone. This area is made of numerous NW-SE trending hercynian inherited structures, reactivated during Mesozoic and Cenozoic times and delimiting holocene coastal marschlands. The main goal of this thesis is to characterize the geometry of potential plio-quaternary active faults in the area by focusing on the Machecoul fault, bounding the Marais Breton and the Baie de Bourgneuf sedimentary basins and potential candidate for the 1799 earthquake. We used a multidisciplinary onshore-offshore approach, including seismology (temporary network), marine geophysics (Chirp and Sparker seismic reflexion, high resolution bathymetry), morphotectonic, gravity, onshore drilling database and historical seismicity.Our results allowed us to analyze and characterize (1) the Machecoul normal faults system structure and geometry in depth, (2) the plio-quaternary depocenters location in Marais Breton and Baie de Bourgneuf in relation with the Machecoul fault system, reaching locally around twenty meters thick, (3) the hydrographic network perturbation and recent incision of the Machecoul fault footwall, probably pliocene aged relief, (4) the microseismic activity of the Machecoul fault. Our data suggest that the plioquaternary sedimentation of the marine and terrestrial basins located in the south of the fault could be controlled by this inherited fault, probably dated from Eocene age.This work confirms the importance of multi-disciplinary approach in the study of faults in low deformation context and provides a body of evidence allowing to connect the Machecoul fault to the rupture of the 1799 Vendée earthquake (M6), historic and reference event in the western part of France given its scale and so its consequences in the more and more densely populated coastal area.
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Sensing systems for active control of sound transmission into cavities

Cazzolato, Ben January 1999 (has links)
Driven by the need to reduce the sound transmitted into aircraft cabins from the power plant, this thesis investigates the active control of sound transmitted through a structure into coupled enclosures. In particular, it examines alternatives to conventional microphone and accelerometer error sensors. This study establishes a design framework for the development and analysis of an active noise control system which can be applied to any complex vibro-acoustic system. The design approach has focused on using techniques presently used in industry to enable the transfer of the active noise control technology from the research stage into practical noise control systems. The structural and acoustic sub-systems are modelled using FEA to estimate the in vacuo structural modal response of the structure and the acoustic pressure modal response (with rigid boundary conditions) of the interior cavity. The acoustic and structural systems are then coupled using modal coupling theory. Within this framework, two novel error sensors aimed at overcoming observability problems suffered by traditional microphone and accelerometer sensors are investigated: namely, acoustic energy density sensors and shaped radiation modal vibration sensors. The principles of the measurement of energy density are discussed and the errors arising from its measurement using two and three-microphone sensor configurations are considered for a one-dimensional reactive sound field and a plane wave sound field. The error analysis encompasses finite separation effects, instrumentation errors (phase and sensitivity mismatches, and physical length errors), diffraction and interference effects, and other sources of error (mean flow and turbulence, temperature and humidity, statistical effects). Following the one-dimensional study, four 3-axis energy density sensor designs are proposed and error analysis is conducted over the same acoustic fields as for the one-dimensional study. The design and construction of the simplest arrangement of the 4 three-axis sensors is discussed with reference to design issues, performance and limitations. The strategy of using energy density control is investigated numerically for a purely acoustic system and a coupled panel-cavity system. Energy density control is shown to provide greater local and global control compared to that possible using an equivalent number of microphones. The performance of the control system is shown to be relatively insensitive to the placement of the energy density sensor. For an enclosed cavity system with high modal overlap, the zone of local control achieved by minimising energy density is found to be approximately the same as the zone of local control obtained when min-imising pressure and pressure gradient in a diffuse sound field. It is also shown that if there is only one control source used per energy density sensor, global control will be almost optimum. The addition of further control sources leads to an improvement in global control, however, the control is no longer optimal. The control system is found to be very tolerant of errors in the estimate of the energy density and thus the use of simpler energy density sensor designs is justified. Finally, an experiment is presented in which the global performance achieved by controlling a three-axis energy density sensor is compared with the performance achieved by minimising the acoustic potential energy and minimising the sum of squared pressures at a finite number of microphones. The experimental results are found to reflect the numerical results. The active minimisation of harmonic sound transmission into an arbitrarily shaped enclosure using error signals derived from structural vibration sensors is investigated numerically and experimentally. It is shown that by considering the dynamics of the coupled system, it is possible to derive a set of "e;structural radiation"e; modes which are orthogonal with respect to the global potential energy of the coupled acoustic space and which can be sensed by structural vibration sensors. Minimisation of the amplitudes of the "e;radiation modes"e; is thus guaranteed to minimise the interior acoustic potential energy. The coupled vibro-acoustic system under investigation is modelled using Finite Element Analysis which allows systems with complex geometries to be investigated rather than limiting the analysis to simple, analytically tractable systems. Issues regarding the practical implementation of sensing the orthonormal sets of structural radiation modes are discussed. Specific examples relating to the minimisation of the total acoustic potential energy within a curved rectangular panel and a coupled cavity are given, comparing the performance offered using vibration sensing of the radiation modes on the structure with the more traditional error sensing; namely, the discrete sensing of the structural kinetic energy on the structural boundary and the acoustic potential energy in the enclosed space approximated by the mean squared pressures at several locations. / Thesis (Ph.D.)--Mechanical Engineering, 1999.

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