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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.
101

The Correlation Between Spectral Moment Measures and Electropalatometric Contact Patterns for /t/ and /k/

Barrett, Janelle 10 September 2012 (has links) (PDF)
Spectral moment analysis has helped further our understanding of the spectral properties of obstruent speech production; however, the physiologic correlates of these spectral measures are not well understood. The aim of the present study was to examine the possible correlations between the linguapalatal contact patterns used to produce the stops /t/ and /k/ and the resulting spectral characteristics. Using spectral moment analysis and electropalatography, the real-word productions of eight speakers of American English were investigated. The spectral measures for the stop consonant tokens in the present study were found to be similar to data reported in previous research with adult speakers. The majority of the correlations examined in this study were found to be statistically insignificant, although significant correlations were found between the anterior vertical and posterior vertical indices with spectral variance and spectral skewness, respectively. Despite the significance of these correlations, this did not account for a large proportion of variance in the data. Further analysis using curve estimates revealed significant curvilinear relationships among the data. These findings may indicate that although the anterior-posterior tongue placement and symmetry of linguapalatal contact contribute to the spectral signature of /t/ and /k/ stop consonants, this articulatory movement is only part of a more complex process that may involve aerodynamic factors and the overall shape of the vocal tract.
102

Nuclear Moments of 140La, 147Nd, and 149Nd

Pierce, Anton Robert 05 1900 (has links)
<p> Using atomic beam magnetic resonance techniques the hyperfine structure (hfs) constants for the magnetic dipole and electric quadrupole interaction, AJ and BJ, have been measured for the following isotopes: 40-hour 140La, 1.8-hour 149Nd and 11-day 147Nd.</p> <p> For 140La the hfs constants are (relative to the J = 5/2 state of 2D) |A5/2| = 55.9(4) MHz, |B5/2| = 38(4) MHz, B5/2/A5/2 > 0. Application of the Fermi-Segre relations in comparison with 139La yields the nuclear moments; μI = (+)0.73(3) n.m., and Q =(+)0.11(4) b. The adopted signs are based on Blok's measured sign of Q for 140La.</p> <p> For 149Nd the hfs constants are: |A4| = 91.0(19) MHz, |B4| = 266(53) MHz, and B4/A4 > 0. Comparison with 145Nd yields μI = (-)0.350(10) nm., and Q = +1.3(3)b. The signs of these moments are based on Q>0 as indicated by nuclear systematics in this region.</p> <p> For 147Nd the hfs constants are |A4| = 143(4) MHz, |B4| = 181(64) MHz, and B4/A4 > 0. Comparison with 145Nd yields |μI| = 0.553(15) n.m., |Q| = 0.9(3) b and μI/Q <0.</p> <p> The error in the 140La magnetic moment allows for a possible 2% hfs anomaly. The quadrupole moments allow for a possible 25% error in the core polarization correction (Sternheimer).</p> <p> These results are discussed in terms of the shell model, the quasi-particle model, and the Nilsson model.</p> / Thesis / Doctor of Philosophy (PhD)
103

Two dimensional EM-scattering by buried penetrable non-circular cylinders using the method of moments /

Izadian, Jamaledin January 1980 (has links)
No description available.
104

Plane wave scattering by thin linear dielectric-coated wires and dielectric strips : a moment method approach with physical basis functions /

Kent, William J. January 1985 (has links)
No description available.
105

A Journey through a Story : Remembering to be a child again with The Little Prince

Chandrasekhar, Harini 28 October 2020 (has links)
myth (n.) A traditional story which embodies a belief regarding some fact or phenomenon of experience, and in which often the forces of nature and of the soul are personified; a sacred narrative regarding a god, a hero, the origin of the world or of a people.2 A parable; An allegory. From the French word mythe (1818) and directly from Modern Latin mythus, which originated from ancient Greek mŷthos : "speech, thought, discourse, word, humour, conversation, story, saga, tale, anything delivered by word of mouth". Attested in English since 1830. Ever since I was a child, I have been fascinated with the fictional world of stories and the act of of storytelling. Always wide-eyed and excited, I remember the countless times that I have lost myself in the mythical worlds in stories. It is moments of sadness or of anxiety, but also of wonder, of ecstasy even, the experience of the beautiful under one or the other of its innumerable forms, the joy of love, of discovery, of happiness in that sense, that are most likely to remind us of our humanity. Hence, when I started my thesis about wanting to explore the design of a built space through the context of storytelling, I was confused. There were these three questions that hounded me at every turn : 1. What is a "place for storytelling"? Does the act of storytelling really exist within the confines of a particular "place"? 2. And if yes, do stories emerge from places? Or do places emerge from stories? What is the nature of the relationship between both? 3. And if places truly are born out of stories, is it possible to craft a journey through a built space akin to our journey through the mythical worlds of a storyteller? / Master of Architecture / What is a "place for storytelling"? Do stories emerge out of built spaces? Or do built spaces emerge out of stories? I had questions on the relevance of architecture in something as raw and primal as the act of storytelling. But what I did not anticipate was that, of all the many different things that I was exploring, the path that I was to actually take would lie in a children's book that I had never heard about before. It was pure serendipity that I chanced upon it, and later it changed my whole thesis in ways that I could not imagine. I realized that I needed not to find "answers" to questions; but rather enjoy this beautiful journey that I was on. The magic of storytelling cannot be shut within walls, but needs to grow outwards. Storytelling is as much about excitement as it is about contemplation. It is about remembering the child within us, and about taking a moment to stop and watch sunsets. It is about rituals and thresholds and gazing at stars. It is about shattering the layers and layers of "grown-up" ideas that we tightly wrap ourselves with. It was when I stopped looking for answers, that I could truly understand what is the nature of the built space that I was dreaming of. Rather than being a single elusive construct - it was an eclectic mix of many different experiences tied together into a journey, guided by a little boy with golden hair.
106

Implementing method of moments on a GPGPU using Nvidia CUDA

Virk, Bikram 12 April 2010 (has links)
This thesis concentrates on the algorithmic aspects of Method of Moments (MoM) and Locally Corrected Nyström (LCN) numerical methods in electromagnetics. The data dependency in each step of the algorithm is analyzed to implement a parallel version that can harness the powerful processing power of a General Purpose Graphics Processing Unit (GPGPU). The GPGPU programming model provided by NVIDIA's Compute Unified Device Architecture (CUDA) is described to learn the software tools at hand enabling us to implement C code on the GPGPU. Various optimizations such as the partial update at every iteration, inter-block synchronization and using shared memory enable us to achieve an overall speedup of approximately 10. The study also brings out the strengths and weaknesses in implementing different methods such as Crout's LU decomposition and triangular matrix inversion on a GPGPU architecture. The results suggest future directions of study in different algorithms and their effectiveness on a parallel processor environment. The performance data collected show how different features of the GPGPU architecture can be enhanced to yield higher speedup.
107

Moment Based Painterly Rendering Using Connected Color Components

Obaid, Mohammad Hisham Rashid January 2006 (has links)
Research and development of Non-Photorealistic Rendering algorithms has recently moved towards the use of computer vision algorithms to extract image features. The feature representation capabilities of image moments could be used effectively for the selection of brush-stroke characteristics for painterly-rendering applications. This technique is based on the estimation of local geometric features from the intensity distribution in small windowed images to obtain the brush size, color and direction. This thesis proposes an improvement of this method, by additionally extracting the connected components so that the adjacent regions of similar color are grouped for generating large and noticeable brush-stroke images. An iterative coarse-to-fine rendering algorithm is developed for painting regions of varying color frequencies. Improvements over the existing technique are discussed with several examples.
108

Probing physics beyond the standard model in diatomic molecules / Tester la physique au-delà du modèle standart dans less molécules diatomiques

Denis, Malika 03 February 2017 (has links)
De nos jours, l'incomplétude du modèle standard des particules est largement reconnue. L'une de ses failles les plus évidentes est le manque d'explication de l'énorme excédent de matière par rapport à l'antimatière dans l'univers, que l'on appelle l'asymétrie baryonique de l'univers. De nouvelles violations de CP (conjugaison de charge et parité spatiale) absentes dans le modèle standard sont supposées être responsables de cette asymétrie. Une telle violation pourrait être observée dans la matière ordinaire à travers un ensemble d'interactions violant les symétries de parité et de renversement du temps (impaires pour P,T) dont les prépondérantes sont les interactions du moment dipolaire électrique de l'électron (eEDM), électron-nucléon scalaire-pseudoscalaire (enSPS) et du moment quadripolaire magnétique nucléaire (nMQM). Ainsi, une preuve expérimentale d'une constante d'interaction impaire pour P,T serait une preuve de cette nouvelle physique au-delà du modèle standard. Le calcul des paramètres moléculaires correspondants est réalisé en utilisant une approche d'interaction de configurations relativiste à quatre composantes dans des molécules diatomiques polaires contenant un actinide, qui sont des systèmes particulièrement appropriés pour les expèriences eEDM, tels que ThO qui a permis d'assigner à l'eEDM la borne supérieure la plus contraignante et ThF+ qui sera utilisé dans une expérience à venir. Ces résultats sont d'une importance cruciale dans l'interprétation des mesures puisque les constantes fondamentales ne peuvent être évaluées que si l'on associe les mesures de décalages énergétiques et les paramètres moléculaires théoriques. / Nowadays, the incompleteness of the Standard Model of particles is largely acknowledged. One of its most obvious shortcomings is the lack of explanation for the huge surplus of matter over antimatter in the universe, the so-called Baryon Asymmetry of the Universe. New CP (Charge conjugation and spatial Parity) violations absent in the SM are assumed to be responsible for this asymmetry. Such a violation could be observed in ordinary matter through a set of interactions violating both parity and time-reversal symmetries (P,T-odd), among which the preponderant ones are the electron Electric Dipole Moment (eEDM), the electron-nucleon scalar-pseudoscalar (enSPS) and the nuclear magnetic quadrupole moment (nMQM) interactions. Hence, an experimental evidence of a non-zero P,T-odd interaction constant would be a probe of this New Physics beyond the Standard Model. The calculation of the corresponding molecular parameters is performed by making use of an elaborate four-component relativistic configuration interaction approach in polar diatomic molecules containing an actinide, that are particularly adequate systems for eEDM experiments, such as ThO that allowed for assigning the most constraining upper bound on the eEDM and ThF+ that will be used in a forthcoming experiment. Those results will be of crucial importance in the interpretation of the measurements since the fundamental constants can only be evaluated if one combines both experimental energy shift measurements and theoretical molecular parameters.
109

Nouvelles contributions à l'application des moments en asservissement visuel / New contributions to the application of moments in visual servoing

Yeremou Tamtsia, Aurélien 11 October 2013 (has links)
Cette thèse propose des contributions très prometteuses au sujet du choix des primitives visuelles en asservissement visuel utilisant les moments 2D extraits de l’image. Nous avons proposé une nouvelle manière de résoudre un problème important en asservissement visuel, à savoir la commande du mouvement de rotation suivant les axes orthogonaux à l’axe optique. Ce travail représente une amélioration significative des travaux précédents en asservissement visuel basé sur l’utilisation des moments 2D extraits de l’image pour commander les degrés de liberté des robots manipulateurs. La commande la plus utilisée est connue sous le nom de commande cinématique. L’approche emploie un descripteur global d’image basé sur des moments 2D "shifted" dont les invariants calculés à partir de ces moments 2D "shifted" utilisent des moments d’ordre faible connus pour être robustes au bruit. De plus, ces invariants choisis ne dépendant pas de la forme de l’objet, sont invariants au mouvement de translation, de rotation et d’échelle. Cette nouvelle façon de faire vient ainsi résoudre les problèmes vus dans les travaux précédents relatifs aux choix des combinaisons des moments invariants basés sur les moments centrés et qui dépendent de la forme de l’objet considéré. Dans les travaux précédents, ces invariants sont calculés avec des moments dont l’ordre est compris entre trois et cinq qui sont vulnérables aux bruits de mesure. D’un point de vue asservissement visuel, le travail est basé sur la détermination explicite de la matrice d’interaction calculée à partir des moments 2D "shifted" dont le choix des paramètres de décalages respectent les propriétés d’invariances aux mouvements de translation, de rotation et d’échelle. En procédant ainsi, les informations visuelles choisies montrent la capacité de représenter les objets de formes symétriques et non symétriques. Des résultats de simulations sont présentés pour illustrer la validité de notre proposition. / This thesis proposes nice and very promising contributions about the choice of visual features in image moments-based visual servoing. We proposed a new way towards solving an important problem in Visual Servoing, namely control of non-optic axis rotational degrees of freedom. This work represents a significant improvement respect to previous works on image-based visual servoing of robot manipulators, with the camera in-hand configuration and under the control scheme known as kinematic control. The approach uses global image features that are based on shifted image moments of a planar target. The improvement consists in a particular selection of a combination of shifted image moments of low order such that they do not depend on the planar target shape ; thus solving the problem seen in related previous works where the selection of central or regular image moments combinations depended on the planar target shapes. From a visual servoing point of view, the work is based on the explicit resolution of the interaction matrix related to any shifted image moment, on the appropriate combination of these moments and on the proper selection of the shifted parameters. By doing so, the new features show improved ability to represent symmetrical objects and several kinds of objects defined from closed contours or from a set of points. Six visual features are selected to design a decoupled control scheme when the object is parallel to the image plane. This nice property is then generalized to the case where the desired object position is not parallel to the image plane. Finally simulated results are presented to illustrate the validity of our proposal.
110

Quantiles univariés et multivariés, approches probabilistes et statistiques : applications radar / Univariate and multivariate quantiles, probabilistic and statistical approaches : radar applications

Decurninge, Alexis 26 January 2015 (has links)
La description et l’estimation des modèles aussi bien univariés que multivariés impliquantdes distributions à queue lourde est un enjeu applicatif majeur. Les L-moments sontdevenus des outils classiques alternatifs aux moments centraux pour décrire les comportementsen dispersion, asymétrie, kurtosis d’une distribution univariée à queue lourde. Eneffet, contrairement aux moments centraux correspondants, ils sont bien définis dès quel’espérance de la distribution d’intérêt est finie. Les L-moments peuvent être vus comme laprojection de la fonction quantile sur une famille orthogonale de polynômes, récupérant lalinéarité inhérente aux quantiles. Nous estimerons dans un premier temps les paramètresde modèles semi paramétriques définis par des contraintes sur ces L-moments par des méthodesde minimisation de divergences.Nous proposons dans un second temps une généralisation des L-moments aux distributionsmultivariées qui passe par la définition d’un quantile multivarié défini comme untransport entre la distribution uniforme sur [0; 1]d et la distribution d’intérêt. Cela nouspermet de proposer des descripteurs pour des distributions multivariées adaptés à l’étudedes queues lourdes. Nous détaillons leurs expressions dans le cadre de modèles possédantdes paramètres de rotation.Enfin, nous proposons des M-estimateurs de la matrice de dispersion des distributions complexeselliptiques. Ces dernières forment un modèle multivarié semi-paramétrique contenantnotamment des distributions à queue lourde. Des M-estimateurs spécifiques adaptésaux distributions elliptiques avec une hypothèse supplémentaire de stationnarité sont égalementproposés. Les performances et la robustesse des estimateurs sont étudiées.Les signaux radar provenant de fouillis tels les fouillis de mer ou les fouillis de sol sontsouvent modélisés par des distributions elliptiques. Nous illustrerons les performances dedétecteurs construits à partir de l’estimation de la matrice de dispersion par les méthodesproposées pour différents scénarios radar pour lesquels la robustesse de la procédure d’estimationest cruciale. / The description and the estimation of univariate and multivariate models whose underlyingdistribution is heavy-tailed is a strategic challenge. L-moments have becomeclassical tools alternative to central moments for the description of dispersion, skewnessand kurtosis of a univariate heavy-tailed distribution. Indeed, contrary to correspondingcentral moments, they are well defined since the expectation of the distribution of interestis finite. L-moments can be seen as projections of the quantile function on a family oforthogonal polynomials. First, we will estimate parameters of semi-parametric modelsdefined by constraints on L-moments through divergence methods.We will then propose a generalization of L-moments for multivariate distributions using amultivariate quantile function defined as a transport of the uniform distribution on [0; 1]dand the distribution of interest. As their univariate versions, these multivariate L-momentsare adapted for the study of heavy-tailed distributions. We explicitly give their formulationsfor models with rotational parameters.Finally, we propose M-estimators of the scatter matrix of complex elliptical distributions.The family of these distributions form a multivariate semi-parametric model especiallycontaining heavy-tailed distributions. Specific M-estimators adapted to complex ellipticaldistribution with an additional assumption of stationarity are proposed. Performancesand robustness of introduced estimators are studied.Ground and sea clutters are often modelized by complex elliptical distributions in the fieldof radar processing. We illustrate performances of detectors built from estimators of thescatter matrix through proposed methods for different radar scenarios.

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