Dissertations / Theses on the topic 'Periodic noise'

La plupart de la littérature considère différents travaux sur le bruit et les vibrations induit par l’écoulement du fluide pour les pièces structurelles de base, comme les plaques de Kirchhoff. L’objectif principal de cette recherche est d’étendre le travail effectué à des structures périodiques ciblant un certain nombre de nouveautés en ce qui concerne différentes échelles: l’échelle aérodynamique, l’échelle de périodicité et l’échelle de fréquence. Même si des approches analytiques et numériques fondées sur des éléments finis (FE) ont été élaborées pour traiter des problèmes particuliers, certaines limites persistent. Par exemple, l’effort de calcul peut facilement devenir lourd même pour les formes structurelles simples ou pour augmenter la fréquence d’excitation; les longueurs d’onde convectives, pour la plupart des cas d’intérêt industriel, sont largement plus petites que les longueurs d’onde flexionnelles et, par conséquent, les maillages deviennent plus exigeantes. Lorsque la complexité structurelle augmente, même les modèles à petite échelle peuvent nécessiter un grand nombre d’éléments augmentant le coût de calcul. Dans les cadres des méthodes basées sur la FE, ce travail propose deux approches numériques pour traiter les vibrations et le bruit induits par une excitation de la couche limite turbulente (TBL) sur les systèmes structurels périodiques. Tout d’abord, une méthode 1D WFE (Wave Finite Element) est développé pour traiter les excitations aléatoires de structures finies plates, courbes et coniques: modèles multicouches et homogénéisés sont utilisés. Dans ce cas, une seule sous-structure est modélisée à l’aide d’éléments finis. À chaque pas de fréquence, des liens périodiques unidimensionnels entre les nœuds sont appliqués pour obtenir l’ensemble des ondes se propageant le long de la direction de la périodicité; la méthode peut être appliquée même pour les systèmes périodiques cycliques. L’ensemble des vagues est successivement utilisé pour calculer les fonctions de transfert de Green entre un ensemble de degrés de liberté cibles et un sous-ensemble représentant les zones chargées. En utilisant une matrice de transfert, les vibrations induites par l’écoulement sont calculées dans un cadre FE. Ensuite, une approche 2D WFE est développée en combinaison avec une synthèse de charge basée sure le nombre d’ondes pour simuler la transmission sonore de structures infinies plates, courbes et axisymétriques: des modèles périodiques homogénéisés et complexes sont analysés. Dans ce cas, les effets de taille finie sont comptabilisés en utilisant une équivalence pour les structures plates et une analogie cylindrique pour les panneaux courbes. Les approches numériques présentées ont été validées avec des résultats analytiques, numériques et expérimentaux pour différents cas d’essai et dans des conditions de charge différentes. En particulier, la réponse analytique et la FEM classique ont été utilisées comme références pour valider les vibrations des plaques et des cylindres sous charge de la couche limite turbulente; la méthode FE a également été utilisée pour valider une structure complexe et effilée sous excitation acoustique diffuse et le calcul du bruit induit par couche limite turbulente. Du point de vue expérimental, l’approche a été validée en comparant les résultats en termes de perte de transmission acoustique évaluée sur les panneaux de fuselage des aéronefs (panneaux composites en nid d’abeille et panneaux courbes à double nervure) sous excitation diffuse du champ acoustique. Enfin, l’utilisation des méthodologies présentées pour l’optimisation vibroacoustique des plaques sandwich, est analysée et proposée à travers certaines études de cas. Les conceptions périodiques standard du cœur sont modifiées en adaptant la propagation des ondes de flexion et de cisaillement par rapport à la fréquence, aux nombres d’ondes acoustiques et convectives. {…]
Most of the literature considers different works on the flow-induced noise and vibrations for basic structural parts, such as Kirchhoff plates. The main objective of this research is to extend the work done to periodic structures targeting a number of novelties with regards to different scales: the aerodynamic scale, the periodicity scale and the frequency scale.Even though analytical and Finite Element(FE)-based numerical approaches have been developed to deal with specific problems, some limits still persist. For example, the computational effort can easily become cumbersome even for simple structural shapes or for increasing excitation frequency; the convective wavelengths, for most industrially-relevant cases, are largely smaller that flexural ones and, thus, the meshing requirements become more demanding. When the structural complexity increases, even small scale models might require a high number of elements increasing computational cost.In the frameworks of FE and WFE based methods, this work proposes two numerical approaches to deal with the vibrations and noise induced by a Turbulent Boundary Layer (TBL) excitation on periodic structural systems. Firstly, a 1D WFE (Wave Finite Element) scheme is developed to deal with random excitations of flat, curved and tapered finite structures: multi-layered and homogenised models are used. In this case a single substructure is modelled using finite elements. At each frequency step, one-dimensional periodic links among nodes are applied to get the set of waves propagating along the periodicity direction; the method can be applied even for cyclic periodic systems. The set of waves is successively used to calculate the Green transfer functions between a set of target degrees of freedom and a subset representing the wetted (loaded) ones. Subsequently, using a transfer matrix approach, the flow-induced vibrations are calculated in a FE framework.Secondly, a 2D WFE approach is developed in combination with a wavenumber-space load synthesis to simulate the sound transmission of infinite flat, curved and axisymmetric structures: both homogenised and complex periodic models are analysed. In this case, finite-size effects are accounted using a baffled window equivalence for flat structures and a cylindrical analogy for curved panels.The presented numerical approaches have been validated with analytical, numerical and experimental results for different test cases and under different load conditions. In particular, analytical response and classic FEM have been used as references to validate the flow-induced vibrations of plates and cylinders under turbulent boundary layer load; FE method has been used also to validate a tapered conical-cylindrical model under diffuse acoustic field excitation and the flow-induced noise computations under TBL. From experimental point of view, the approach has been validated comparing results in terms of transmission loss evaluated on aircraft fuselage panels (composite honeycomb and doubly-ribbed curved panels) under diffuse acoustic field excitation.Finally, the use of the presented methodologies for the vibroacoustic optimization of sandwich plates, is analysed and proposed through some case-studies. Standard periodic core designs are modified tailoring the bending and shear waves' propagation versus frequency against the acoustic and convective wavenumbers. The resulting sound transmission losses are computed using the numerical approaches developed in this work and validated with measurements under diffuse acoustic field, taken from 3D-printed models. Strong increases of sound transmission loss are observed for fixed mass of the plates and between 1.5 kHz and 10 kHz

In this thesis, we study the existence of pathwise random periodic solutions to both the semilinear stochastic differential equations with linear multiplicative noise and the semilinear stochastic partial differential equations with linear multiplicative noise in a Hilbert space. We identify them as the solutions of coupled forward-backward infinite horizon stochastic integral equations in general cases, and then perform the argument of the relative compactness of Wiener-Sobolev spaces in C([0, T],L2Ω,Rd)) or C([0, T],L2(Ω x O)) and Schauder's fixed point theorem to show the existence of a solution of the coupled stochastic forward-backward infinite horizon integral equations.

Thesis (Ph. D.)--University of California, San Diego, 2009.
Title from first page of PDF file (viewed June 16, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 159-167).

In this work present the broad-band noise structure in the 2-60 keV data of Cataclysmic Variables (CVs) with Anomalous X-Ray Pulsars (AXPs) and Soft Gamma Repeaters (SGRs). We analyzed Rossi X-ray Timing Explorer (RXTE) PCA data and derived time series from 27 CVs, 4 AXPs and 1 SGR using the RXTE archive. In general, CVs of different types all show broad band noise which can be fitted with power laws, using exponentional cut-offs, and Lorentzians in a similar way to power spectral (noise) characteristics of X-ray Binaries (XRBs). In general terms the power spectra show a power law index of (-)1.2-2. A rather large scale flattening of the power spectra exits in nonmagnetic systems in the low to very low frequency range. We observe that in low and high states/outbursts the noise in the high frequency range and low frequency range is changed. CVs show considerably low frequency noise. In addition, we recovered several possible QPOs in the X-ray wavelengths from CVs mainly from Intermediate Polar systems. AXP and SGR sources which are thought to be powered by either magnetic decay or accretion show band limited noise in their low frequencies. We also correlated their equal time interval noise characteristic with their burst states and discovered that in the two AXPs (1E 2259+586, 1E 1048.1-5937) noise correlates with their bursts.

All physical systems are affected by some noise that limits the resolution that can be attained in partitioning their state space. For chaotic, locally hyperbolic flows, this resolution depends on the interplay of the local stretching/contraction and the smearing due to noise. My goal is to determine the `finest attainable' partition for a given hyperbolic dynamical system and a given weak additive white noise. That is achieved by computing the local eigenfunctions of the Fokker-Planck evolution operator in linearized neighborhoods of the periodic orbits of the corresponding deterministic system, and using overlaps of their widths as the criterion for an optimal partition. The Fokker-Planck evolution is then represented by a finite transition graph, whose spectral determinant yields time averages of dynamical observables. The method applies in principle to both continuous- and discrete-time dynamical systems. Numerical tests of such optimal partitions on unimodal maps support my hypothesis.

Cette thèse porte sur des techniques de contrôle optimal pour des systèmes issus de la mécanique quantique et de la résonance magnétique nucléaire. Le travail présenté dans ce mémoire est divisé en quatre parties.Dans la première partie, nous nous sommes intéressés au contrôle optimal simultané de l’équation de Schrödinger dépendante du temps via un champ laser qui représente le contrôle et que nous supposons soumis à une famille de perturbations. Ceci nous conduit à considérer un problème d’optimisation multi-critère via l’introduction d’un ensemble de fonctionnelles de coût à minimiser (au sens de Pareto).Dans la deuxième partie, nous étudions le cadre mathématique de l’équation de Bloch périodique. Les conditions d’optimalité nécessaires du premier ordre sont étudiées. Plus précisément, nous prouvons l’existence d’une solution périodique, ainsi que l’existence d’un optimum.Dans la troisième partie, nous présentons un nouvel algorithme d’optimisation pour les dynamiques périodiques. Cet algorithme est appliqué à la maximisation du signal sur bruit en résonance magnétique nucléaire. Le travail réalisé est ici avant tout numérique et algorithmique. Il s’agit à notre connaissance du premier algorithme de contrôle quantique permettant de considérer des dynamiques périodiques en temps. Nous avons montré l’efficacité de cette méthode pour le cas d’un système de spins homogènes et inhomogènes.La dernier partie permet de présenter l’algorithme de Shinnar-Le-Roux (SLR) qui est une méthode d’optimisation analytique. Des résultats numériques ont été réalisés en comparant cette méthode avec une méthode itérative de type GRAPE introduite dans les chapitres précédents. Le résultat de cette comparaison donne un avantage à l’algorithme SLR
This thesis deals with optimal control techniques for systems related to quantum mechanics and nuclear magnetic resonance. The work presented in this memory is divided into four parts.In the first part, we focus on to the simultaneous optimal control of the Schrödinger time-dependent equations via a laser field that represents a control term and that is assumed to be submitted to a family of perturbations. This lead us to consider a multi-criteria optimization problem through the introduction of a set of cost functional to be minimized (in the sense of Pareto).In the second part, we study the mathematical framework of the periodic Bloch equation. The necessary first-order optimality conditions are derived. More precisely, we prove the existence of a periodic solution, as well as the existence of an optimum.In the third part, we present a new optimization algorithm for periodic dynamics. This algorithm is applied to the maxi- mization of SNR in NMR. The work here is more of an numerical and algorithmic nature. To our knowledge, this is the first quantum control algorithm to consider periodic dynamics in time. We have shown the efficiency of this method in the case of a homogeneous and inhomogeneous spin system.The last part presents the Shinnar-Le-Roux algorithm (SLR), which is an analytical optimization method. Numerical results were obtained by comparing this method with an iterative grape-type method introduced in previous chapters. The result of this comparison gives an advantage to the SLR algorithm

Дослідження індукованого шумом руху становить фундаментальну проблему статистичної фізики. Згідно другого закону термодинаміки у рівноважному стані внутрішній шум не здатен викликати направлений рух частинок. При виведенні системи із стану рівноваги такий рух стає можливим (за умови порушення поступальної інваріантності у просторі або часі). Для вивчення подібних ефектів, як правило, у систему вносять елемент порушення симетрії періодичного потенціалу, який і задає напрямок руху частинок.

The article describes a method for detection of the reference signal, with presence of the periodic additive noise. The characteristics of noise are unknown. The problem is reduced to finding the occurrence of a proportional relationship between some intermediate signals after a time interval equal to the period of the noise. The appearance of proportional relationship detected with using the function of disproportionality by the first order derivative.

Un modèle de voie périodique a été développé afin de réduire le bruit émis dans l'environnement durant le passage d'un train. Ce modèle, prenant en compte les déformations de la section du rail, couvre une large gamme de fréquences, 0 - 5000 Hz. La considération d'un appui discret le rend cependant moins performant dans les hautes fréquences, pour lesquelles les ondes propagatives émises sur une travée ont une longueur d'onde proche de la longueur d'appui. Une méthode générale d'analyse des milieux périodiques unidimensionnels est alors proposée afin de prendre en compte l'effet de la longueur d'appui

This thesis tests and applies a new, physically based snow distribution and melt model at spatial scales of tens of metres and temporal scales of days across sub-arctic landscapes, in order to assess the significance of snow variability in sub-arctic human ecodynamics at resolutions relevant to human activities. A wider goal is to contribute to planning in the face of future climate change. Model tests are undertaken based on original field data collected in Sweden and Norway, and secondary data from Idaho, France and Greenland. Model applications focus on the ‘completed experiment’ of the medieval Norse in Greenland, a comparatively isolated population that relied on a combination of pastoralism and hunting for survival. A combination of local calibration based on contemporary meteorological data, customised climate reconstructions based on GCM data, new archaeological survey and new DEM are used in order to apply the model. This thesis shows, for the first time, the likely range of snow depth and duration experienced across the medieval Norse Greenland landscape as a result of climate and vegetation change. Results show that increases in snow cover could have been significant drivers of transformative change in Norse Greenland, and are therefore likely to be key in understanding the potential impact of future climate changes on similar sub-arctic and relatively marginal communities. Selected model analyses simulate the total spring (April-June) snow cover at the homefields to range from 32% cover lasting 6 days in the most favourable climate to 100% cover lasting 45 days in the most unfavourable climate at key elite inner fjord farms. At the more isolated outer fjord farms, total spring snow cover ranges from 33% cover lasting 10 days in the most favourable climate to 100% cover lasting 60 days in the most unfavourable climate. Increased climate variance and recovery times, as experienced by the Norse, are potential early warning signals of threshold-crossing change. Model results show that these signals could have been masked for the Norse decision making elite because they were located in the most favourable and least snow covered locations. Masking could have been further increased through the intensified seal hunting implemented by the Norse as an adaption strategy, and these actions could have developed into a rigidity trap. When the conjunctures of the 15th century developed in terms of increased sea ice, snow cover, storminess, culture contact, changing trade and sea level rise, it was too late to develop different responses. Whilst current populations have improved technology and knowledge relative to the Norse Greenlanders, there is a risk that adaptations will lack long-term utility, spatially restricted indications of change may be ignored, and rigidity traps develop. This thesis provides an additional tool for understanding a key element of both the past and possible futures of subarctic human ecodynamics.

The first millennia BC and AD were a key period in the settlement history of Atlantic Scotland. There is a dramatic increase in the number and diversity of archaeological monuments, many of which are domestic in nature. The sites contain thousands of ecofacts and artefacts, allowing detailed insights into the workings and developments in everyday life across many different sites for the first time. The use of plants by humans would have been an essential component in many of these developments. Prior to this study, little direct evidence for human/plant interactions was available in the Western Isles, a pivotal location in the wider North Atlantic realm. The research focuses analysing and interpreting new carbonised plant macrofossil assemblages from nine multi-period sites in Lewis, the largest island in the Western Isles. A regional sampling strategy was employed, allowing direct statistical comparison of the archaeobotanical remains. Due consideration is given to the taphonomy of the carbonised plant assemblages. A generic model is proposed for most remains, involving the carbonisation of the plant material on household fires, followed by the spread of the ash and the carbonised material across the sites by various anthropogenic and natural transforms. Measurement of the mineral magnetic signatures of on-site sediments supports this model, highlighting both the distribution of ash and its correlation with macrofossil concentration in the stratigraphy. A new technique was also developed, using mineral magnetic measurements of experimental fire ashes to source the fuels used in the household fires. Application of this technique to ash from the archaeological sites indicated that well-humified peat was the principal fuel employed. Four interpretative research themes relating to the use of plants are then addressed. These include the arable economy, the management and procurement of wood and timber, the deliberate gathering of plants and the social dimension of plant use. Integration of these research themes resulted in the construction of a generic annual cycle of the human/plant interaction, requiring sophisticated systems of social co-operation, territoriality and land-division. Comparative analysis demonstrates that the cycle varied over time and space and also changed subtly over the wider region. Finally, various aspects of the cycle are highlighted with regard to the broader social developments occurring during the first millennia BC and AD.

A partir de l'etude du sport au benin, au congo, au niger et au senegal, ce travail tente de mettre en evidence les differents processus de cooperation entre acteurs politiques et sportifs de la colonisation a la periode post-coloniale. S'il y a convergence de strategies entre africains et francais aboutissant a un transfert de modele institutionnel, on peut constater la preponderance des actions de la confejes (conference des ministres de la jeunesse et des sports des pays d'expression francaise) a travers des politiques concertees mises au point d'une part et celle du programme de solidarite olympique d'autre part dont les etats sont tributaires. Ce sont les etats plutot que les nations qui reproduisent le sport occidental grace aux aides pour la formation des cadres, des nations et surtout pour le fonctionnement des comites nationaux olympiques afin de maintenir l'universalite du sport olympique. Vouloir construire une communaute internationale hors des identites culturelles locales et avec des valeurs exterieures est certainement une entreprise exaltante. Mais, elle correspond plus au principe d'une politique generale qu'a celui de la solidarite inter-active des cultures. Il revient a chacun d'en tirer les consequences.

The research contained in these papers embodies both results from direct archaeological investigation and also the development of techniques (geophysical, chronological and geoarchaeological) in order to understand long-term settlements and their associated landscapes in Orkney and Shetland. Central to this research has been the study of soil management strategies of arable plots surrounding settlements from the Neolithic to the Iron Age. It is argued that this arable system provides higher yields in marginal locations. The ability to enhance yield in good years and to store surplus can mitigate against shortage. Control and storage of this surplus is seen as one catalyst for the economic power of elite groups over their underlying or 'client' population. The emergence of a social elite in the Iron Age, building brochs and other substantial roundhouses of near broch proportions, is seen as being linked to the control of resources. Evidence at the site of Old Scatness indicated that there was a continuity of wealth and power from the Middle Iron Age through the Pictish period, before the appearance of the Vikings produced a break in the archaeological record. The Viking period saw a break in building traditions, the introduction of new artefacts and changes in farming and fishing strategies. Each of the papers represents a contribution that builds on these themes.

The research contained in these papers embodies both results from direct archaeological investigation and also the development of techniques (geophysical, chronological and geoarchaeological) in order to understand long-term settlements and their associated landscapes in Orkney and Shetland. Central to this research has been the study of soil management strategies of arable plots surrounding settlements from the Neolithic to the Iron Age. It is argued that this arable system provides higher yields in marginal locations. The ability to enhance yield in good years and to store surplus can mitigate against shortage. Control and storage of this surplus is seen as one catalyst for the economic power of elite groups over their underlying or ¿client¿ population. The emergence of a social elite in the Iron Age, building brochs and other substantial roundhouses of near broch proportions, is seen as being linked to the control of resources. Evidence at the site of Old Scatness indicated that there was a continuity of wealth and power from the Middle Iron Age through the Pictish period, before the appearance of the Vikings produced a break in the archaeological record. The Viking period saw a break in building traditions, the introduction of new artefacts and changes in farming and fishing strategies. Each of the papers represents a contribution that builds on these themes.

The deposition of animals in graves was an essential aspect of burial practice in Scandinavia during the Vendel Period and Viking Age (550–1050 AD). While this rite occurs in many different regions, it is most clearly observed in the boat-graves from the famous cemeteries in Swedish Uppland, such as Vendel and Valsgärde, as well as in a number of high-status cremation graves. Former studies have tended to interpret faunal remains from burial contexts as food offerings, diplomatic gifts or simply as sacrifices. These explanations place an emphasis on the importance of the human dead and imply that grave assemblages mainly served to accompany the deceased as a provision for the afterlife, or to illustrate power, status and identity among the living. The master’s thesis presented here, comprises an analysis of animal depositions from both cremation and inhumation burials in Uppland. By applying the theory of agency, this study focuses on grave assemblages and human-animal relationships as a means of understanding burial practices. Instead of only paying attention to the type of bones and the animal species, it is equally important to consider the condition of the bones, their placement inside the grave and the placement of artefacts ascribed to certain animals in relation to the human dead. This is not only essential to decoding human-animal relationships as evident in burial practices, but also to understanding the many different processes that culminated in the deposition of animal bones in graves.

У роботі розроблено математичний апарат та засіб компонентного виявлення корисних стохастично-періодичних радіосигналів в телекомунікаційних мережах на принципах ЕТСС через застосування теорії ПКВП та компонентної обробки. На базі математичного апарату побудовано алгоритм ефективного виявлення корисних стохастично-періодичних радіосигналів у телекомунікаційних мережах із завадами шляхом обчислення компонент кореляційних як кількісних показників виявлення. Розроблено засіб ефективного виявлення стохастично-періодичних радіосигналів у телекомунікаційних мережах із завадами у вигляді програмного коду при використанні MATLAB для телекомунікаційних систем. Здійснено емпіричне дослідження процесу виявлення стохастично-періодичних радіосигналів у телекомунікаційних мережах із завадами, яке підтвердило факт працездатності розробленого засобу виявлення корисних радіосигналів.
The mathematical apparatus and means of component detection of useful stochastic-periodic radio signals in telecommunication networks on the principles of ETSS through the application of the theory of PCSP and component processing are developed in the work. On the basis of the mathematical apparatus the algorithm of effective detection of useful stochastic-periodic radio signals in telecommunication networks with interferences by calculation of components of correlation as quantitative indicators of detection is constructed. A tool for effective detection of stochastic-periodic radio signals in telecommunication networks with interference in the form of program code when using MATLAB for telecommunication systems has been developed. An empirical study of the process of detection of stochastic-periodic radio signals in telecommunications networks with interference, which confirmed the fact of the development of the developed means of detecting useful radio signals.
ВСТУП 8 РОЗДІЛ 1. ОСНОВНА ЧАСТИНА 10 1.1. Завади в телекомунікаційних мережах 10 1.1.1. Електромагнітні завади 10 1.1.2. Завади обладнання мережі 12 1.2. Методи виявлення радіосигналів в телекомунікаційних мережах 16 1.2.1. Метод усереднення радіосигналів 16 1.2.2. Фільтрація радіосигналів 17 1.2.3. Кореляція радіосигналів 21 1.3. Висновки до розділу 2 23 РОЗДІЛ 2. ОСНОВНА ЧАСТИНА 24 2.1. Особливості радіосигналів у телекомунікаційних мережах 24 2.2. Математичний апарат ПКВП як зображення радіосигналів 26 2.3. Компонентний метод виявлення радіосигналів 30 2.4. Алгоритм виявлення радіосигналів 32 2.5. Висновки до розділу 3 36 РОЗДІЛ 3. НАУКОВО-ДОСЛІДНА ЧАСТИНА 37 3.1. Блок-схема програмного засобу виявлення радіосигналів 37 3.2. Програмна реалізація засобу виявлення радіосигналів 38 3.3. Результати виявлення радіосигналів 41 3.4. Оцінювання результатів виявлення радіосигналів 44 3.5. Інтерфейс засобу виявлення радіосигналів 46 3.6. Висновки до розділу 3 48 РОЗДІЛ 4. ОХОРОНА ПРАЦІ ТА БЕЗПЕКА В НАДЗВИЧАЙНИХ СИТУАЦІЯХ 49 4.1. Охорона праці 49 4.2. Безпека в надзвичайних ситуаціях 52 4.3. Висновки до розділу 4 55 ЗАГАЛЬНІ ВИСНОВКИ 56 ПЕРЕЛІК ПОСИЛАНЬ 57 ДОДАТКИ 60 ДОДАТОК А. Копія тези 61 ДОДАТОК Б. Скрипт компонентної обробки радіосигналу 65 ДОДАТОК В. Скрипт програмного засобу виявлення радіосигналів 66 ДОДАТОК Г. Скрипт програмного засобу виявлення радіосигналів із інтерфейсом 67

Le bruit de la circulation routière, et en particulier le bruit des deux-roues motorisés, constituent une importante source de gêne sonore. Afin d’estimer l’exposition sonore dans les villes de plus 100 000 habitants, la directive européenne 2002/49/CE impose la réalisation de cartes de bruit stratégiques, basées sur l’indice Lden. Cet indice est également utilisé dans des relations exposition-réponse, afin de prédire les pourcentages de personnes gênées, notamment par le bruit du trafic routier. En couplant les cartes de bruit stratégiques et ces relations exposition-réponse, des cartes de gêne pourraient être établies. Toutefois, la pertinence de cet indice pour prédire la gêne due au bruit en milieu urbain est souvent remise en cause, car de nombreux facteurs acoustiques influents (e.g. les caractéristiques spectrales et temporelles) ne sont pas pris en compte par cet indice. Cette thèse vise à améliorer la caractérisation de la gêne due au bruit de trafic routier urbain en considérant différentes compositions de trafic et la présence des deux-roues motorisés. Dans ce but, des expériences sont menées en conditions contrôlées. Une première étude a porté sur l’influence de plusieurs facteurs acoustiques relatifs aux périodes de calme et aux bruits de passage de véhicules sur la gêne due au bruit de trafic routier urbain. Cette étude a conclu à l’influence de la présence de périodes de calme et du nombre de véhicules au sein du trafic routier urbain et à l’absence d’influence de l’ordre des véhicules routiers, de la position et de la durée des périodes de calme. Ces résultats ont été utilisés afin de mener la caractérisation physique et perceptive de différentes compositions de trafic routier urbain. La régression multi-niveau a été utilisée pour calculer la gêne, en considérant 1) des facteurs acoustiques influents à l’aide de combinaisons pertinentes d’indices et 2) un facteur non acoustique : la sensibilité au bruit. Dans les villes, le bruit routier est souvent entendu en situation de multi-exposition avec d’autres bruits. Dans le cadre de ces travaux de thèse, les situations de multi-exposition aux bruits routier et d’avion ont été étudiées. Pour cela, un travail semblable à celui mené pour le bruit de trafic routier urbain a été mené pour le bruit d’avion conduisant également à des combinaisons pertinentes d’indices. En vue de caractériser les gênes dues aux bruits de trafic routier et d’avion pour des situations de multi-exposition sonore, les données des précédentes expériences ainsi que celles d’une expérience conduite en situation de multi-exposition à ces bruits combinés ont été utilisées au travers d’une régression multi-niveau adaptée, comme cela a pu être mené dans la littérature. La régression multi-niveau a ainsi permis la proposition de modèles de gêne pour chaque source de bruit. Puis, la gêne totale due à des situations de multi-exposition à ces bruits a été étudiée, afin de mettre en évidence les phénomènes perceptifs mis en jeu. Des modèles de gêne totale ont été proposés, en utilisant les modèles de gêne due à chaque source. Enfin, les modèles de gêne obtenus pour chaque source et les modèles de gêne totale ont été confrontés aux données d’une enquête socio-acoustique. A cet effet, une méthodologie a été proposée afin d’estimer les différents indices des modèles à partir des valeurs du Lden, issues de cartes de bruit et utilisées pour définir l’exposition au bruit des personnes enquêtées. Cette confrontation a montré que les modèles proposés à partir d’expériences menées en laboratoire et couplés à la méthodologie d’estimation des indices à partir des valeurs du Lden permettent une bonne prédiction de la gêne in situ
Road traffic noise, and in particular powered two-wheeler noise, constitute an important source of noise annoyance. In order to estimate the noise exposure in cities of more than 100 000 inhabitants, the European directive 2002/49/EC requires the elaboration of strategic noise maps, based on the Lden index. This index is also used in exposureresponse relationships, to predict the percentages of annoyed people, by road traffic noise for example. By coupling strategic noise maps and these exposure-response relationships, noise annoyance maps could be established. The relevance of this index to predict noise annoyance in cities is however often questioned, since many influential acoustical factors (e.g. spectral and temporal features) are not considered by this index. The aim of this thesis is to enhance the characterization of noise annoyance due to different compositions of urban road traffic including powered two-wheelers. To achieve this goal, experiments were carried out under controlled conditions. A first study concerned the influence of several acoustical features related to quiet periods and vehicle pass-by noises on the annoyance due to urban road traffic noise. This study demonstrated the influence of the presence of quiet periods and of the number of vehicles within the urban road traffic and to the absence of the influence of the order of the vehicle pass-by noises, the position and duration of quiet periods. These results were used to carry out the physical and perceptual characterization of different compositions of urban road traffic noise. Multilevel regression was used to calculate noise annoyance, by coupling combinations of indices relating to influential acoustical features and an individual factor: noise sensitivity. In cities, road traffic noise is often combined with other noises. In the framework of this thesis, noise exposure to road traffic noise combined with aircraft noise was studied. Therefore, the same work as the one performed for urban road traffic noise was carried out for aircraft noise, leading also to relevant combinations of noise indices. In order to characterize annoyances due to road traffic noise and to aircraft noise in a combined exposure situation, data from the previous experiments and from an experiment dealing with these combined noises were used through an appropriate multilevel regression, as done in literature. The regression allows annoyance models for each noise source to be proposed. Then, total annoyance due to combined noises was studied, in order to highlight the perceptual phenomena related to the combined exposure. Total noise annoyance models were proposed, using proposed annoyance model of each noise source. Finally, these single source annoyance models and total annoyance models were tested using data of a socio-acoustic survey. To do this, a methodology has been proposed to estimate the different indices involved in the annoyance models, from the Lden values obtained from the strategic noise maps and used to define the noise exposure of the respondents. This confrontation showed that the models proposed on the basis of experiments carried out under laboratory conditions and coupled with a methodology of estimation of the noise indices from Lden values, enabled a good prediction of in situ annoyance

L'utilisation des moyens de transport et des machines au quotidien a fortement contribué à l'amplification des phénomènes générant de la nuisance sonore. L'élimination des bruits en basses fréquences est actuellement la cible de différentes recherches. Plusieurs stratégies ont émergé comme l'utilisation des résonateurs de Helmholtz, de membranes vibrantes mais surtout des systèmes hybrides actif-passif. L'originalité de ce projet de doctorat consiste en la proposition d'une solution technologique d'un résonateur de Helmholtz adaptatif à volume variable, permettant ainsi de s'affranchir du caractère mono-fréquentiel des résonateurs de Helmholtz passifs. Le réglage de volume s'effectue grâce à l'utilisation d'une membrane en polymère électroactif (EAP), permettant ainsi d'accorder les résonances du système. Le comportement mécanique de ces matériaux est modifié lorsqu'ils sont stimulés par un champ électrique. Des améliorations significatives en perte par transmission acoustique sont obtenues en basses fréquences par deux effets: la variation de raideur de la membrane et l'augmentation de volume due à la déformation de la membrane. Des études numériques, analytiques et expérimentales sont réalisées pour déterminer le potentiel des concepts proposés. Enfin, une structure périodique contenant 9 résonateurs adaptatifs à membranes électroactives est étudiée en champs diffus permettant d'évaluer les performances acoustiques du concept distribué.

Génératrice depuis le VIe siècle de notre ère de crises épidémiques récurrentes en Occident, la peste a profondémentmarqué l’histoire des sociétés européennes, tant sur le plan biologique que culturel, économique et politique. Sil’histoire des épidémies qu’elle a engendrées est aujourd’hui relativement bien connue, un certain nombre de questionssur ses caractéristiques épidémiologiques passées demeurent pour partie irrésolues. En particulier, le caractère sélectifou non de la mortalité par peste à l’égard de l’âge, du sexe et de l’état de santé préexistant des individus faitactuellement débat. À partir d’une approche anthropobiologique, le présent travail se propose de contribuer à cettediscussion. Il livre les résultats de l’étude d’un corpus de 1090 squelettes provenant, d’une part, de quatre sitesd’inhumation de pestiférés de la fin du Moyen Âge et du début de l’époque moderne et, d’autre part, de deuxcimetières paroissiaux médiévaux utilisés hors contexte épidémique. Cette étude révèle en premier lieu l’existenced’une signature démographique commune aux séries en lien avec la peste. Leur composition par âge et par sexe,distincte de celle caractérisant la mortalité naturelle, est au contraire en adéquation avec la structure théorique d’unepopulation vivante préindustrielle. L’examen de divers indicateurs de stress suggèrent par ailleurs que les victimes dela peste jouissaient, à la veille de leur décès, d’un meilleur état de santé que les individus morts en temps normal. Lesrésultats obtenus concourent à démontrer que les facteurs causals de ces lésions squelettiques, d’accoutuméresponsables d’une diminution des chances de survie, n’eurent au contraire qu’une influence mineure, si ce n’est nulle,sur le risque de mourir de l’infection à Yersinia pestis. Ce travail livre in fine un faisceau d’arguments convergents quitendent à prouver que les épidémies de peste anciennes furent à l’origine d’une mortalité non sélective, la maladiefrappant indistinctement les individus des deux sexes, de tous âges et de toutes conditions sanitaires
From the 6th century onwards, plague caused recurring mortality crises in the Western world. Such epidemics hadprofound biological, cultural, economic and political impacts on European societies. Some aspects of the history ofplague epidemics are currently well known, but many questions remain unanswered, such as the preciseepidemiological pattern of the disease in ancient times. It is unclear whether plague killed people indiscriminately orwhether this disease was selective with respect to age, sex and health. This research contributes to this debate.It consists of an anthropological and paleopathological study of skeletal remains of 1090 individuals, including plaguevictims from four medieval and post-medieval burial grounds, and individuals from two parochial cemeteries in useduring periods of normal mortality. Results from the four plague-related assemblages reveal a peculiar demographicsignature. Age and sex distribution differs clearly from what is expected in non-epidemic periods, when it is shown tocorrespond closely to the demographic structure of the living population. Moreover, the study of various non-specificskeletal stress markers shows that plague victims were in a better health before they passed away than people who diedin non-epidemic periods. The results demonstrate that individuals who suffered stress and disease had a reducedchance of survival in non-epidemic periods, whereas they were not at a higher risk to die during plague epidemics.This study provides evidence that plague was not selective, and that it killed regardless of sex, age, and pre-existing health

Dans les cités grecques, et particulièrement dans les systèmes démocratiques, l’exercice des magistratures amenait de nombreux citoyens à manier de l’argent public. L’oikonomos est l’une des magistratures financières civiques qui s’épanouit dans l’ensemble du monde grec à la fin de l’époque classique et pendant la période hellénistique, et plus précisément en Asie Mineure et dans les cités du Pont-Euxin.Le terme oikonomos renvoie à l’administration de l’oikos, l’unité économique et sociale de la société grecque. L’organisation de l’oikos et les pratiques déployées pour assurer la survie et le développement de ses membres, correspondent à des principes élémentaires connus depuis les poèmes épiques. À partir de la fin du Ve siècle, l’oikonomos est identifié comme détenteur d’une technè qui suscite les réflexions philosophiques dans la cité d’Athènes. Il est reconnu comme l’agent de la pratique de l’oikonomia, la science de la gestion domestique. À une époque de changements économiques, politiques et sociaux importants, les philosophes et les prosateurs font le lien entre la gestion domestique et l’administration des affaires de la cité. Grâce à l’apport des sources littéraires, notre enquête permet d’identifier et de comprendre le passage qui s’effectue à la fin du IVe siècle entre l’oikonomos, gestionnaire de l’oikos et la magistrature civique. Dans un second temps, l’étude des sources épigraphiques met en lumière le rôle et la place de la magistrature dans les cités où elle est attestée. Le plus souvent magistrat unique, l’oikonomos intervient à la fois dans le règlement des dépenses et dans la prise en charge matérielle des honneurs décrétés par la cité. Néanmoins, il n’est pas le seul magistrat. Trésoriers, néôpes ou d’autres magistratures, financières ou non, ont des rapports étroits avec l’oikonomos. L’analyse de leurs relations apporte des éléments de compréhension à la fois sur les attributions des oikonomoi, sur la chaîne des responsabilités engagées dans le processus de publication et de résolution des honneurs et enfin sur la gestion des finances des cités
In Greek cities, and especially in democratic systems, many citizens had to deal with public money. The oikonomos is one of the civic financial magistracies that spread throughout the Greek world in classical and Hellenistic times but especially in Asia Minor and Pont-Euxin.Firstly, the oikonomos refers to the administration of the oikos, the economic and social unit of Greek society. The organisation of the oikos and the practices implemented to ensure the survival and development of its members correspond to elementary principles known since epic poems. From the end of the 5th century onwards, the oikonomos has been identified as the holder of a technè that stimulated philosophical reflection in the city of Athens. The oikonomos was identified as the agent of the practice of oikonomia, the science of domestic management. In an era of significant economic, political and social change, philosophers established the link between domestic management and the administration of the city's affairs. The analysis of literary sources has made it possible to identify and understand the transition that took place at the end of the 4th century between the oikonomos, the manager of the oikos, and the civic magistracy. Secondly, the study of epigraphic sources highlights the role and place of the oikonomos in the cities where it is documented. In most cases, there was only one holder of the magistracy. The oikonomos was involved both in the payment of expenses and in the material support for the honours decreed by the city. Sometimes it may has been associated with other people. Treasurers, neopes or other financial or non-financial magistrates worked with the oikonomos. The analysis of their relationships provides elements for understanding not only the attributions of oikonomoi, the chain of the responsibilities involved in the process of honours publication and resolution but also on the management of the cities' finances

The purpose of this study is to analyze the distribution, forms, and function(s) of iron amulets deposited in the late Iron Age gravefields of Lovö, with the goal of ascertaining how (and so far as possible why) these objects were utilized in rituals carried out during and after burials. Particular emphasis is given to re-interpreting the largest group of iron amulets, the iron amulet rings, in a more relational and practice-focused way than has heretofore been attempted. By framing burial analyses, questions of typology, and evidence of ritualized actions in comparison with what is known of other cult sites in Mälardalen specifically– and theorized about the cognitive landscape(s) of late Iron Age Scandinavia generally– a picture of iron amulets as inscribed objects made to act as catalytic, protective, and mediating agents is brought to light.

碩士
國立臺灣大學
電信工程學研究所
105
This thesis focuses on the problem of Electromagnetic Interference (EMI) of Printed Circuit Board (PCB) routing noise. It first considered Defected Ground Structure (DGS) to suppress noise for EMI improvement, but found it causing another EMI problem. Hence, a novel non-periodic Electromagnetic-Bandgap (EBG) structure is proposed in this thesis. By combining non-periodic EBG and de-coupling capacitors, the propagation characteristics are investigated and an design rule is proposed. The full-wave EM simulation, ADS and GTEM cell measurement are used to validate the accuracy of the proposed analysis and design. Finally, miniaturization of the non-periodic EBG is also addressed.

碩士
康寧大學
資訊傳播研究所
99
In this study, discrete wavelet transform is used to experiment with image. Experimental image noise reduction by periodic. Enhancement pattern for different images. Wavelet filter before the image to the average best way to preserve the image information. Average filter is still the best way,when retained wavelet transform image compression. But the best way to histogram equalization is restored the wavelet. When the performance of the image to Photo mode, Text section does not apply histogram equalization. So when the image was produced after the impact of periodic noise, to deal with the discrete wavelet image, Restore or not to be considered. To get the best results. One of the primary purposes of the CVIPtools development is to allow students, faculty, and other researchers to explore the power of computer processing of digital images.The new Windows version of CVIPtools, developed at the Computer Vision and Image Processing Laboratory here at Southern Illinois University at Edwardsville, under the continuing direction of Dr. Scott E Umbaugh, is currently available with the textbook, Digital Image Processing and Analysis The image used in this study compared CVIPtools. Apply using the more simple than MATLAB.

The Phase-Locked Loop (PLL) is commonly used for frequency synthesis in RF transceivers. It can be implemented in two architectures, namely, fractional-N and integer- N. In this thesis, the integer-N architecture is chosen due to its suitability for frequency planning. Here, a PLL with a low noise output is important to ensure signal purity. There are two dominant noise sources in a PLL, namely, phase noise and periodic noise. In the integer-N PLL, periodic noise is also referred to as a reference spur, where the noise gives rise to multiple reference frequency offsets at the PLL output. Of these two noise sources, this thesis is focused on the analysis and suppression of reference spurs. It is because less work has been carried in the literature regarding spurs, and phase noise is better studied. The main factors underlying reference spurs are discussed. These factors are mainly from the charge pump and phase/frequency detector (PFD) circuit non-idealities, namely, PFD delay, charge pump current leakage, charge pump current mismatch, and rise and fall times characteristic of the charge pump current. Reference spur magnitude can be predicted via a transient analysis. The simulation is time consuming, as the reference spur magnitude can only be captured after the PLL in its locked state. Therefore, the simulation period has to be set long enough to ensure enough data can be obtained to read that state. In this thesis, a reference spur mathematical analysis is presented to accurately estimate the reference spur magnitude. In the analysis, all the circuit non-idealities that contribute to the reference spur are considered. Circuit parameters required in the mathematical analysis can be obtained from transistor level simulation for each circuit. As the simulation for each circuit can be carried out separately, a large amount of simulation time can be saved. The proposed mathematical analysis also can be used to determine the major contributing factor to the problem of reference spurs. The reference spur also can be estimated via behavioural modelling simulation. Behavioural modelling of the PLL using Simulink is presented in this thesis. Each PLL component is modelled separately, and circuit non-idealities contributing to the reference spur are included in the behavioural model. In addition to reference spur estimation, the PLL behavioural model also can be used to visualise the dynamic behaviour of the system. Results from the spur analysis show that a slight mismatch current in the charge pump helps to improve the reference spur performance. This thesis presents an analysis to determine an optimum charge pump current ratio for reference spur suppression, which is caused by the charge pump current mismatch and the switching delay. Further, a ratioed current charge pump circuit is proposed to replace the conventional charge pump circuit for a reference spur performance improvement. This spur suppression technique is implemented using a 180 nm SiGe BiCMOS technology for performance evaluation.
Thesis (Ph.D. )-- University of Adelaide, School of Electrical and Electronic Engineering, 2013

Ce travail présente deux nouveaux systèmes simples d'analyse de la marche humaine grâce à une caméra de profondeur (Microsoft Kinect) placée devant un sujet marchant sur un tapis roulant conventionnel, capables de détecter une marche saine et celle déficiente. Le premier système repose sur le fait qu'une marche normale présente typiquement un signal de profondeur lisse au niveau de chaque pixel avec moins de hautes fréquences, ce qui permet d'estimer une carte indiquant l'emplacement et l'amplitude de l'énergie de haute fréquence (HFSE). Le second système analyse les parties du corps qui ont un motif de mouvement irrégulier, en termes de périodicité, lors de la marche. Nous supposons que la marche d'un sujet sain présente partout dans le corps, pendant les cycles de marche, un signal de profondeur avec un motif périodique sans bruit. Nous estimons, à partir de la séquence vidéo de chaque sujet, une carte montrant les zones d'irrégularités de la marche (également appelées énergie de bruit apériodique). La carte avec HFSE ou celle visualisant l'énergie de bruit apériodique peut être utilisée comme un bon indicateur d'une éventuelle pathologie, dans un outil de diagnostic précoce, rapide et fiable, ou permettre de fournir des informations sur la présence et l'étendue de la maladie ou des problèmes (orthopédiques, musculaires ou neurologiques) du patient. Même si les cartes obtenues sont informatives et très discriminantes pour une classification visuelle directe, même pour un non-spécialiste, les systèmes proposés permettent de détecter automatiquement les individus en bonne santé et ceux avec des problèmes locomoteurs.
This work presents two new and simple human gait analysis systems based on a depth camera (Microsoft Kinect) placed in front of a subject walking on a conventional treadmill, capable of detecting a healthy gait from an impaired one. The first system presented relies on the fact that a normal walk typically exhibits a smooth motion (depth) signal, at each pixel with less high-frequency spectral energy content than an abnormal walk. This permits to estimate a map for that subject, showing the location and the amplitude of the high-frequency spectral energy (HFSE). The second system analyses the patient's body parts that have an irregular movement pattern, in terms of periodicity, during walking. Herein we assume that the gait of a healthy subject exhibits anywhere in the human body, during the walking cycles, a depth signal with a periodic pattern without noise. From each subject’s video sequence, we estimate a saliency color map showing the areas of strong gait irregularities also called aperiodic noise energy. Either the HFSE or aperiodic noise energy shown in the map can be used as a good indicator of possible pathology in an early, fast and reliable diagnostic tool or to provide information about the presence and extent of disease or (orthopedic, muscular or neurological) patient's problems. Even if the maps obtained are informative and highly discriminant for a direct visual classification, even for a non-specialist, the proposed systems allow us to automatically detect maps representing healthy individuals and those representing individuals with locomotor problems.

This research investigates the realization of parametric amplification in superconducting circuits and structures where nonlinearity is provided by Josephson junction (JJ) elements. We aim to develop a systematic analysis over JJ-based devices toward design of novel traveling-wave Josephson parametric amplifiers (TW-JPA). Chapters of this thesis fall into three categories: lumped JPA, superconducting periodic structures and discrete Josephson transmission lines (DJTL). The unbiased Josephson junction (JJ) is a nonlinear element suitable for parametric amplification through a four-photon process. Two circuit topologies are introduced to capture the unique property of the JJ in order to efficiently mix signal, pump and idler signals for the purpose of signal amplification. Closed-form expressions are derived for gain characteristics, bandwidth determination, noise properties and impedance for this kind of parametric power amplifier. The concept of negative resistance in the gain formulation is observed. A design process is also introduced to find the regimes of operation for gain achievement. Two regimes of operation, oscillation and amplification, are highlighted and distinguished in the result section. Optimization of the circuits to enhance the bandwidth is also carried out. Moving toward TW-JPA, the second part is devoted to modelling the linear wave propagation in a periodic superconducting structure. We derive closed-form equations for dispersion and s-parameters of infinite and finite periodic structures, respectively. Band gap formation is highlighted and its potential applications in the design of passive filters and resonators are discussed. The superconducting structures are fabricated using YBCO and measured, illustrating a good correlation with the numerical results. A novel superconducting Transmission Line (TL), which is periodically loaded by Josephson junctions (JJ) and assisted by open stubs, is proposed as a platform to realize a traveling-wave parametric device. Using the TL model, this structure is modeled by a system of nonlinear partial differential equations (PDE) with a driving source and mixed-boundary conditions at the input and output terminals, respectively. This model successfully emulates parametric and nonlinear microwave propagation when long-wave approximation is applicable. The influence of dispersion to sustain three non-degenerate phased-locked waves through the TL is highlighted. A rigorous and robust Finite Difference Time Domain (FDTD) solver based on the explicit Lax-Wendroff and implicit Crank-Nicolson schemes has been developed to investigate the device responses under various excitations. Linearization of the wave equation, under small-amplitude assumption, dispersion and impedance analysis is performed to explore more aspects of the device for the purpose of efficient design of a traveling-wave parametric amplifier. Knowing all microwave characteristics and identifying different regimes of operation, which include impedance properties, cut-off propagation, dispersive behaviour and shock-wave formation, we exploit perturbation theory accompanied by the method of multiple scale to derive the three nonlinear coupled amplitude equations to describe the parametric interaction. A graphical technique is suggested to find three waves on the dispersion diagram satisfying the phase-matching conditions. Both cases of perfect phase-matching and slight mismatching are addressed in this work. The incorporation of two numerical techniques, spectral method in space and multistep Adams-Bashforth in time domain, is employed to monitor the unilateral gain, superior stability and bandwidth of this structure. Two types of functionality, mixing and amplification, with their requirements are described. These properties make this structure desirable for applications ranging from superconducting optoelectronics to dispersive readout of superconducting qubits where high sensitivity and ultra-low noise operation is required.