Dissertations / Theses: 'Spectral moments analysis'

1

Pielaszkiewicz, Jolanta Maria. "Contributions to High–Dimensional Analysis under Kolmogorov Condition." Doctoral thesis, Linköpings universitet, Matematisk statistik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-122610.

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This thesis is about high–dimensional problems considered under the so{called Kolmogorov condition. Hence, we consider research questions related to random matrices with p rows (corresponding to the parameters) and n columns (corresponding to the sample size), where p > n, assuming that the ratio $\frac{p}{n}$ converges when the number of parameters and the sample size increase. We focus on the eigenvalue distribution of the considered matrices, since it is a well–known information–carrying object. The spectral distribution with compact support is fully characterized by its moments, i.e., by the normalized expectation of the trace of powers of the matrices. Moreover, such an expectation can be seen as a free moment in the non–commutative space of random matrices of size p x p equipped with the functional $\frac{1}{p}E[Tr\{\cdot\}]$ . Here, the connections with free probability theory arise. In the relation to that eld we investigate the closed form of the asymptotic spectral distribution for the sum of the quadratic forms. Moreover, we put a free cumulant–moment relation formula that is based on the summation over partitions of the number. This formula is an alternative to the free cumulant{moment relation given through non{crossing partitions ofthe set. Furthermore, we investigate the normalized $E[\prod_{i=1}^k Tr\{W^{m_i}\}]$ and derive, using the dierentiation with respect to some symmetric matrix, a recursive formula for that expectation. That allows us to re–establish moments of the Marcenko–Pastur distribution, and hence the recursive relation for the Catalan numbers. In this thesis we also prove that the $\prod_{i=1}^k Tr\{W^{m_i}\}$ , where $W\sim\mathcal{W}_p(I_p,n)$ , is a consistent estimator of the $E[\prod_{i=1}^k Tr\{W^{m_i}\}]$ . We consider $Y_t=\sqrt{np}\big(\frac{1}{p}Tr\big\{\big(\frac{1}{n}W\big)^t\big\}-m^{(t)}_1 (n,p)\big),$ , where $m^{(t)}_1 (n,p)=E\big[\frac{1}{p}Tr\big\{\big(\frac{1}{n}W\big)^t\big\}\big]$ , which is proven to be normally distributed. Moreover, we propose, based on these random variables, a test for the identity of the covariance matrix using a goodness{of{t approach. The test performs very well regarding the power of the test compared to some presented alternatives for both the high–dimensional data (p > n) and the multivariate data (p ≤ n).

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2

Weaver, Andrea Lynn. "The Effect of a Lingual Magnet on Fricative Production: An Acoustic Evaluation of Placement and Adaptation." Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd1009.pdf.

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Riml, Joakim. "Solute Transport Across Scales : Time Series Analyses of Water Quality Responses to Quantify Retention and Attenuation Mechanisms in Watersheds." Doctoral thesis, KTH, Vattendragsteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-149528.

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The intra-continental movement of waterborne contaminants is governed by the distribution of solute load in the landscape along with the characteristics and distribution of the hydrological pathways that transport the solutes. An understanding of the processes affecting the transport and fate of the contaminants is crucial for assessments of solute concentrations and their environmental effect on downstream recipients. Elevated concentration of nutrients and the presence of anthropogenic substances, such as pharmaceutical residues, are two examples of the current problems related to hydrological transport. The overall objective of this thesis is to increase the mechanistic understanding of the governing hydrological transport processes and their links to geomorphological and biogeochemical retention and attenuation processes. Specifically, this study aims to quantify the processes governing the transport and fate of waterborne contaminants on the point, stream reach, and watershed scales by evaluating time series obtained from stream tracer tests and water quality monitoring data. The process quantification was achieved by deriving formal expressions for the key transport characteristics, such as the central temporal moments of a unit solute response function and the spectral scaling function for time series of solute responses, which attributes the solute response in the Laplace and Fourier domains to the governing processes and spatial regions within the watershed. The results demonstrate that in addition to the hydrological and biogeochemical processes, the distribution of the load in the landscape and the geomorphological properties in terms of the distribution of transport pathway distances have defined effects on the solute response. Furthermore, the spatial variability between and along the transport pathways significantly affect the solute response. The results indicate that environments with high retention and attenuation intensity, such as stream-reaches with pronounced hyporheic zones, may often dominate the solute flux in the watershed effluent, especially for reactive solutes. The mechanistic-based framework along with the evaluation methodologies presented within this study describes how the results can be generalized in terms of model parameters that reflect the hydrology, geomorphology and biogeochemistry in the studied area. This procedure is demonstrated by the parameterization of a compartment-in-series model for phosphorous transport.

QC 20140826

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Wing, Lindsey McCall. "Native Mandarin Speakers' Production of English Fricatives as a Function of Linguistic Task Type and Word Position: A Spectral Moment Analysis." BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/7313.

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The purpose of this study was to analyze the phonetic production of fricatives across differing word positions and task types. Further knowledge about the fricative production of second language learners of English would potentially improve the ability to teach correct pronunciation and improve the productivity of second language programs. All participants in this study were native speakers of Mandarin Chinese with English as their second language. A total of 12 subjects participated, all of whom had English proficiency ratings ranging from novice to advanced. The speakers were between 21-51 years of age, with each speaker having between 2 to 6 years of experience learning English in their country of origin. Using acoustic and spectral moment analyses, the acoustic nature of four types of fricative productions (/f/, /Î¸/, /s/, and /Êƒ/) were analyzed as a function of linguistic task type and word position. Although a number of measures were found to differ significantly as a function of word position and task type, the majority of statistical analyses were not found to be significant. This lack of significance may be due to the specific methodology used, the speakers<'> atypical voicing patterns, and/or decreased length of sound productions. Findings of this study may indicate that second language learners<'> production of fricatives vary minimally across differing word positions and task types.

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Ballikaya, Elif. "Analysis Of Slot Coupled Microstrip Patch Antennas." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609094/index.pdf.

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Method of Moments (MoM)/Green&rsquo
s function formulation is developed for the analysis of electromagnetic radiation from planar rectangular microstrip antennas with different feeding techniques. Investigated structures are microstrip line fed patch antenna, proximity coupled patch antenna and slot coupled patch antenna. For all these structures equivalent problems are defined. Then, integral equations where currents are the unknowns are obtained from boundary conditions and by using spectral domain representation of Green&rsquo
s functions. Finally, MoM is applied to convert these integral equations to a system of linear equations. Currents on the conducting surfaces as well as equivalent magnetic currents on the apertures are modeled as a sum of piecewise sinusoidal subdomain basis functions with unknown coefficients which are calculated by solving the system of linear equations. Based on the formulations provided in this study, a Fortran code is developed. Numerical results calculated by using the code are presented in the form of patch and line currents and input impedances. Presented results are in good agreement with the results given in the literature.

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Nissen, Shawn L. "An Acoustic Analysis of Voiceless Obstruents Produced by Adults and Typically Developing Children." The Ohio State University, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=osu1041225568.

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Bhandari, Kuntal. "Boundary controllability of some coupled parabolic systems with Robin or Kirchhoff conditions." Thesis, Toulouse 3, 2020. http://www.theses.fr/2020TOU30063.

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Dans cette thèse, on étudie la contrôlabilité à zéro par le bord de quelques systèmes paraboliques linéaires couplés par des termes de couplage intérieur et/ou au bord. Le premier chapitre est une introduction à l'ensemble du manuscrit. Dans le deuxième chapitre, on rappelle les principaux concepts et résultats autour des notions de contrôlabilité qui seront utilisés dans la suite. Dans le troisième chapitre, on étudie principalement la contrôlabilité par le bord d'un système couplé 2x2 de type cascade avec des conditions au bord de Robin. En particulier, on prouve que les contrôles associés satisfont des bornes uniformes par rapport aux paramètres de Robin et convergent vers un contrôle de Dirichlet lorsque les paramètres de Robin tendent vers l'infini. Cette étude fournit une justification, dans le contexte du contrôle, de la méthode de pénalisation qui est couramment utilisée pour prendre en compte des données de Dirichlet peu régulières en pratique. Dans le quatrième et dernier chapitre, on étudie d'abord la contrôlabilité à zéro d'un système 2x2 en dimension 1 contenant des termes de couplage à la fois à l'intérieur et au bord du domaine. Plus précisément, on considère une condition de type Kirchhoff sur l'un des bords du domaine et un contrôle de Dirichlet sur l'autre bord, dans l'une ou l'autre des équations. En particulier, on montre que les propriétés de contrôle du système diffèrent selon que le contrôle agisse sur la première ou sur la seconde équation, et selon les valeurs du coefficient de couplage intérieur et du paramètre de Kirchhoff. On étudie ensuite un modèle 3x3 avec un ou deux contrôle(s) aux limites de Dirichlet à une extrémité et une condition de type Kirchhoff à l'autre extrémité ; ici la troisième équation est couplée (couplage intérieur) avec la première. Dans ce cas, on obtient ce qui suit : en considérant le contrôle sur la première équation, on a contrôlabilité conditionnelle dépendant des choix du coefficient de couplage intérieur et du paramètre de Kirchhoff, et en considérant le contrôle sur la deuxième équation, on obtient toujours une contrôlabilité positive. En revanche, considérer un contrôle sur la troisième équation conduit à un résultat de contrôlabilité négative. Dans cette situation, on a besoin de deux contrôles aux limites sur deux des trois équations pour retrouver la contrôlabilité. Enfin, on expose quelques études numériques basées sur l'approche pénalisée HUM pour illustrer les résultats théoriques, ainsi que pour tester d'autres exemples
In this thesis, we study the boundary null-controllability of some linear parabolic systems coupled through interior and/or boundary. We begin by giving an overall introduction of the thesis in Chapter 1 and we discuss some essentials about the notion of parabolic controllability in the second chapter. In Chapter 3, we investigate the boundary null-controllability of some 2x2 coupled parabolic systems in the cascade form where the boundary conditions are of Robin type. This case is considered mainly in space dimension 1 and in the cylindrical geometry. We prove that the associated controls satisfy suitable uniform bounds with respect to the Robin parameters, which let us show that they converge towards a Dirichlet control when the Robin parameters go to infinity. This is a justification of the popular penalization method for dealing with Dirichlet boundary data in the framework of the controllability of coupled parabolic systems. Coming to the Chapter 4, we first discuss the boundary null-controllability of some 2x2 parabolic systems in 1-D that contains a linear interior coupling with real constant coefficient and a Kirchhoff-type condition through which the boundary coupling enters in the system. The control is exerted on a part of the boundary through a Dirichlet condition on either one of the two state components. We show that the controllability properties vary depending on which component the control is being applied; the choices of interior coupling coefficient and the Kirchhoff parameter play a crucial role to deduce positive or negative controllability results. Thereafter, we study a 3x3 model with one or two Dirichlet boundary control(s) at one end and a Kirchhoff-type boundary condition at the other; here the third equation is coupled (interior) through the first component. In this case we obtain the following: treating the control on the first component, we have conditional controllability depending on the choices of interior coupling coefficient and the Kirchhoff parameter, while considering a control on the second component always provides positive result. But in contrast, putting a control on the third entry yields a negative controllability result. In this situation, one must need two boundary controls on any two components to recover the controllability. Further in the thesis, we pursue some numerical studies based on the penalized Hilbert Uniqueness Method (HUM) to illustrate our theoretical results and test other examples in the framework of interior-boundary coupled systems

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8

Xu, Shulan. "Effect of Uncertainty of Rock Properties on Radionuclide Transport by Groundwater : Implications for Performance Assessments of the Repository of Spent Nuclear Fuel in Heterogeneous Bedrock." Doctoral thesis, Uppsala University, Department of Earth Sciences, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-544.

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The overall objective of the current study is to develop a quantitative understanding of the effects of spatial variability in physical and geochemical properties of crystalline rock on the migration of radionuclides along a single fracture in bedrock. A stochastic model was developed to describe the transport of solutes in fractured rock. The model describes the migration of radionuclides along a one-dimensional path and includes the transversal diffusion into the rock matrix and sorption kinetics. By using a Lagrangian method of description we can extend the model to the description of a two-dimensional transport problem in single fractures.

This study presents the first analysis of the impact of heterogeneous mass transfer on the transport of radionuclides in rock fractures, where most of the relevant rock properties such as aperture, porosity, effective diffusivity, sorption capacity and maximum diffusion depth are defined as being spatially random. The stochastic analysis performed here reflects the uncertainty in our knowledge of the properties associated with a discrete sampling technique in site investigations.

Geostatistics of the main parameters was determined experimentally on a large number of rock samples taken from the Swedish crystalline basement. The knowledge of the covariance functions of the main rock properties is then used as a basis for a stochastic analysis. By combining the small perturbation approach with the spectral method the problem could be solved in terms of closed form solutions for the central temporal moments of the residence time probability density function.

In order to be able to distinguish between the effects of various mechanisms from the effects of heterogeneity on the migration of radionuclides, it was necessary to perform independent studies of the effect of the variation of the dispersion coefficient on the aspect ratio of a rectangular flow section and the effect of adsorption kinetics on the migration.

Finally, the effect of the heterogeneous rock properties on the solute transport observed in a limited number of migration experiments corresponds fairly well to the theoretical effect expected on the basis of the experimentally determined auto-covariance functions.

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9

Silva, T?rcio de Lima. "An?lise de onda completa de superf?cie seletiva em freq??ncia do tipo anteparo duplo." Universidade Federal do Rio Grande do Norte, 2011. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15383.

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Made available in DSpace on 2014-12-17T14:55:55Z (GMT). No. of bitstreams: 1 TercioLS_DISSERT.pdf: 2173183 bytes, checksum: 0473c9e56e2e2ec2462372a52af84fd3 (MD5) Previous issue date: 2011-12-21
This work presents a theoretical analysis and numerical and experimental results of the scattering characteristics of frequency selective surfaces, using elements of type patch perfectly conductor. The structures are composed of two frequency selective surfaces on isotropic dielectric substrates cascaded, separated by a layer of air. The analysis is performed using the method of equivalent transmission line in combination with the Galerkin method, to determine the transmission and reflection characteristics of the structures analyzed. Specifically, the analysis uses the impedance method, which models the structure by an equivalent circuit, and applies the theory of transmission lines to determine the dyadic Green's function for the cascade structure. This function relates the incident field and surface current densities. These fields are determined algebraically by means of potential incidents and the imposition of the continuity of the fields in the dielectric interfaces. The Galerkin method is applied to the numerical determination of the unknown weight coefficients and hence the unknown densities of surface currents, which are expanded in terms of known basis functions multiplied by these weight coefficients. From the determination of these functions, it becomes possible to obtain numerical scattered fields at the top and bottom of the structures and characteristics of transmission and reflection of these structures. At work, we present numerical and experimental results for the characteristics of transmission and reflection. Comparisons were made with other results presented in literature, and it was observed a good agreement in the cases presented suggestions continuity of the work are presented
Esse trabalho apresenta uma an?lise te?rica e resultados num?ricos e experimentais das caracter?sticas de espalhamento de superf?cies seletivas em frequ?ncia, que usam elementos do tipo patch perfeitamente condutor. As estruturas s?o compostas por duas superf?cies seletivas em frequ?ncia sobre substratos diel?tricos isotr?picos cascateadas, separadas por uma camada de ar. A an?lise ? efetuada utilizando-se o m?todo da linha de transmiss?o equivalente em combina??o com o m?todo de Galerkin, visando determinar as caracter?sticas de transmiss?o e reflex?o das estruturas analisadas. Especificamente, a an?lise usa o m?todo da imped?ncia, que modela a estrutura por meio de um circuito equivalente e, aplica-se a teoria de linhas de transmiss?o para determinar a fun??o di?dica de Green, para a estrutura em cascata. Esta fun??o relaciona os campos incidentes e as densidades superficiais de corrente. Estes campos s?o determinados algebricamente por meio dos potenciais incidentes e da imposi??o da continuidade dos campos nas interfaces diel?tricas. O m?todo de Galerkin ? aplicado na determina??o num?rica dos coeficientes pesos desconhecidos e, consequentemente, das densidades superficiais de correntes desconhecidas, que s?o expandidas em termos de fun??es de base conhecidas multiplicadas por esses coeficientes peso. A partir da determina??o destas fun??es, torna-se poss?vel a obten??o num?rica dos campos espalhados no topo e na base das estruturas e das caracter?sticas de transmiss?o e de reflex?o destas estruturas. No trabalho, s?o apresentados resultados num?ricos e experimentais para as caracter?sticas de transmiss?o e de reflex?o. Foram efetuadas compara??es com outros resultados apresentados na literatura, tendo-se observado uma boa concord?ncia nos casos analisados Sugest?es de continuidade do trabalho s?o apresentadas

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Södergren, Anders. "Asymptotic Problems on Homogeneous Spaces." Doctoral thesis, Uppsala universitet, Matematiska institutionen, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-132645.

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This PhD thesis consists of a summary and five papers which all deal with asymptotic problems on certain homogeneous spaces. In Paper I we prove asymptotic equidistribution results for pieces of large closed horospheres in cofinite hyperbolic manifolds of arbitrary dimension. All our results are given with precise estimates on the rates of convergence to equidistribution. Papers II and III are concerned with statistical problems on the space of n-dimensional lattices of covolume one. In Paper II we study the distribution of lengths of non-zero lattice vectors in a random lattice of large dimension. We prove that these lengths, when properly normalized, determine a stochastic process that, as the dimension n tends to infinity, converges weakly to a Poisson process on the positive real line with intensity 1/2. In Paper III we complement this result by proving that the asymptotic distribution of the angles between the shortest non-zero vectors in a random lattice is that of a family of independent Gaussians. In Papers IV and V we investigate the value distribution of the Epstein zeta function along the real axis. In Paper IV we determine the asymptotic value distribution and moments of the Epstein zeta function to the right of the critical strip as the dimension of the underlying space of lattices tends to infinity. In Paper V we determine the asymptotic value distribution of the Epstein zeta function also in the critical strip. As a special case we deduce a result on the asymptotic value distribution of the height function for flat tori. Furthermore, applying our results we discuss a question posed by Sarnak and Strömbergsson as to whether there in large dimensions exist lattices for which the Epstein zeta function has no zeros on the positive real line.

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11

Benredjem, Djamel. "Etude théorique du déplacement des raies spectrales par effet de polarisation dans les plasmas denses : cas des raies de l'hélium hydrogenoïde." Paris 6, 1986. http://www.theses.fr/1986PA066016.

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Le déplacement des raies de l'hélium hydrogenoïde émises dans les plasmas denses a été calculé en considérant l'effet des électrons libres et celui des ions perturbateurs sur l'émetteur. Le premier, déterminé par une méthode de potentiel auto-consistant, induit un déplacement vers le rouge alors que le second, calcule par perturbation, décale les raies vers le bleu. Deux méthodes de calcul de cette grandeur ont été développées : l'une permet d'évaluer le déplacement comme moment spectral du profil complet; l'autre, plus simple, séparé les deux contributions et peut s'appliquer à des états très excités. Les résultats théoriques obtenus sont en accord quantitatif avec les expériences les plus récentes.

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Alvites, José Carlos Valencia. "Rigorous results for the particle spectrum of lattice quantum chromodynamics moldels in the strong coupling regime." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/55/55135/tde-09092016-144325/.

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In this thesis, using rigorous methods, we determine the low-lying energy-momentum spectrum of a lattice Quantum Chromodynamics model (QCD) in dimension 3 + 1, imaginary time and in the strong coupling regime. We consider a QCD model with the Wilson action, three quark avors and 4 X 4 Dirac spin matrices. Under these conditions, we reanalyze que question about the existence of baryon particles in the context of the Gell-Mann and Ne´eman Eightfold Way. Completing previous works, where the octet baryons where shown to exist, here we prove the existence of the decuplet baryons detected by showing the existence of isolated dispersion curves in the energy-momentum espectrum restricted to the subspace of the physical quantum-mechanical Hilbert H of the model, associated with states with an odd number of fermions. Besides, we obtain some smoothness properties veried by these curves, as well as analytical properties of the spectral measure for the two-baryon correlations. Also, the octet and the decuplet baryons are shown to be the only states in the odd subspace up to near the energy threshold of the meson-baryon bound state. Using the results obtained here, we can go up in the spectrum and validate some previously obtained results on the two-baryon bound state spectrum beyond the so called ladder approximation, for the complete model.
Nessa tese, usando métodos rigorosos, determinamos a parte inicial do espectro de energia-momento para o modelo de Cromodinâmica Quântica (QCD) na rede, em dimensão 3 + 1, com tempo imaginário e no regime de acoplamento forte. Consideramos o modelo de QCD com a ação de Wilson, três sabores de quarks e matrizes de spin de Dirac 4 X 4. Sob estas condições, reconsideramos a questão da demonstração da existência de bárions, no contexto do Eightfold Way de Gell-Mann e Ne ´eman. Complementando trabalhos anteriores onde a existência dos octetos de bárions foi demonstrada, aqui demonstramos a existência dos decupletos de bárions. Estas partículas são detectadas através de curvas de dispersão isoladas no espectro de energia-momento do modelo, considerando-se o subespaço H0, do espaço de Hilbert (quântico) físico H, com vetores com um número ímpar de férmions. Além disso, obtemos propriedades de suavidade destas curvas, assim como propriedade analíticas da medida espectral da correlação de dois bárions. Estes bárions são demonstrados ser os únicos estados espectrais no modelo, no subespaço ímpar, até o limiar de energia próximo do estado méson-bárion. Com os resultados obtidos nesta tese, podemos subir no espectro e validar, para o modelo completo, resultados espectrais envolvendo estados ligados de dois-bárion obtidos anteriormente na chamada aproximação escada (dominante).

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Boyer, Eric. "Estimation paramétrique de moments spectraux d'échos doppler : application aux radars strato-troposphériques." Cachan, Ecole normale supérieure, 2002. http://www.theses.fr/2002DENS0037.

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Pacchiani, Francesco. "Etude sismologique des failles normales actives du Rift de Corinthe." Paris 11, 2006. https://tel.archives-ouvertes.fr/tel-01576334.

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Le travail de recherche effectué dans la présente thèse a pour but d'analyser la géométrie des failles actives en profondeur et d'étudier la relation entre les failles, la sismicité et les fluides, afin de comprendre le mécanisme de déformation dans un contexte d'extension continentale. La région d'étude est le Rift de Corinthe (Grèce) dont la microsismicité de l'année 2001 est relocalisée par analyse spectrale, ce qui permet d'obtenir une image haute résolution des structures actives en profondeur. A partir de l'analyse de la géométrie de la sismicité relocalisée, nous montrons, premièrement, l'existence d'une zone de faille dont la trace en surface coïncide avec la Vallée de Kerinitis, où nous proposons qu'elle affleure, deuxièmement, que la Faille d'Aigion n'est pas listrique jusqu'à 6. 5km de profondeur et troisièmement, nous suggérons une corrélation entre le pendage et la profondeur des multiplets du rift. L'étude spatio-temporelle de la crise sismique de 2001 montre une migration de la sismicité de 0. 02 km/jour vers la surface, que nous supposons liée au mouvements de fluides en profondeur, et une perméabilité du milieu de 7 x 10e-13 m^2 qui est cohérente avec la perméabilité supposée d'une croûte tectoniquement stable. D'autre part, un programme a été développé pour calculer la magnitude de moment, MOMAG. Ces résultats confirment le modèle généralement accépté pour le Rift de Corinthe: l'extension est accomodée par des failles planes en surface et une structure à faible pendage assimilée à un détachement en profondeur. En outre, ils mettent en évidence l'hétérogénéité des failles et la participation des fluides dans les mécanismes de déformation extensive
The research work effectuated in the present thesis aims to constrain the deformation mecanisms in the context of continental extension by carrying out an analysis of the geometry of the active faults at depth as well as by studying the relation between faults, seismicity and fluids. The study region is the Corinth Rift (Greece) whose microseismicity of year 2001 has been relocated by spectral analysis, thereby enabling a high resolution image of the active structures at depth. From the study of the geometry of the relocated seismicity, we show, first, the existence of a fault zone whose surfacet trace coincides with the Kerinitis Valley, where we propose that it outcrops second, that the Aigion Fault is not listric down to 6. 5 km depth and third we suggest a correlation between the dip and the depth of the rift's multiplets. The spatio-temporal study of the 2001 seismic crisis shows a 0. 02 km/day migration of the seismicity towards the surface that we propose related to fluid motion at depth. The estimated rock permeability, 7 x 10e-13 m^2, is coherent with other estimates as well as with the supposed permeability of tectonically stable crust. Moreover a program, MOMAG, has been developed to calculate the moment magnitude. The resulting overall b value in the rift, b=1. 35, shows that at depth the medium is heterogeneous. The diverse results obtained confirm the generally accepted Corinth Rift model: the extension is accommodated by planar faults at the surface and by a weakly dipping structure at depth, assimilated to a detachment. Furthermore, they evidence the fault heterogeneity and the involvement of fluids in the extensional deformation mecanisms

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Tine, Modou. "Etude à haute résolution des spectres infrarouges d'un isotope rare HTO de la vapeur d'eau et des états excités de H2Te présentant un comportement en modes locaux." Paris 11, 2004. http://www.theses.fr/2004PA112206.

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Au cours de cette thèse, on a procédé d'abord à une étude du spectre d'absorption haute résolution de la bande nu3 de HTO, de 3500 à 3890 cm-1. Les transitions rotationnelles de cette bande ont été attribuées en ayant recours à des combinaisons de différences. Les nombres d'ondes des transitions ont été analysés grâce à un programme de moindres-carrés afin de remonter aux constantes spectroscopiques. Un état perturbateur a pu être mis en évidence. Afin de construire une base de données à usage spectroscopique pour cette bande, un calcul de la fonction moment dipolaire de HTO a été entrepris. Dans un deuxième temps, une analyse du spectre d'absorption haute résolution de H2Te a été effectuée dans la région 4500 à 6000 cm-1. Les bandes (30±,0) ? (00+,0) et (20±,1) ? (00+,0) ont pu être identifiées. L'attribution des transitions rotationnelles a été effectuée. Pour la bande (30±,0) ? (00+,0) les nombres d'ondes ont pu être reproduits avec un seul jeu de constantes rotationnelles plus un terme de couplage de Coriolis pour l'état du haut. En accord avec les développements théoriques relatifs aux modes locaux, ceci est la preuve d'un comportement en mode locaux pour les états (30±,0). Un tel comportement n'a pas pu être mis en évidence pour les états (20±,1) situés plus bas en énergie
In the first part of this thesis an analysis of the high-resolution spectrum of the HTO molecule nu3 band, from 3500 to 3890 cm-1, was undertaken. The rotational transitions of this band were assigned using combination differences. Their wavenumbers were analyzed with a least squares fit program in order to obtain spectroscopic parameters. A perturbing state was evidenced. With a view towards building a spectroscopic data base for this band, a calculation of the dipole moment function was undertaken. In the second part of this thesis, an analysis of the high-resolution spectrum of H2Te was carried out in the 4500 to 6000 cm-1 region. Two vibrational bands were observed which were assigned as the (30±,0) ? (00+,0) et (20±,1) ? (00+,0) bands. Rotational transitions were afterwards assigned. For the (30±,0) ? (00+,0) band, wavenumbers could be reproduced using only one set of rotational constants plus a Coriolis coupling term for the the upper vibrational state. In agreement with local mode theory, this clearly shows that the (30±,0) states displays a local mode behavior. This was not the case for the (20±,1) states characterized by lower energies

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González-Caneda, María. "Investigation Of Source Parameters Of Earthquakes In Northern Sweden." Thesis, Uppsala universitet, Geofysik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-380133.

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By studying the frequency domain of seismic signals generated by earthquakes, the source parameters can be recovered, i.e., the seismic moment (M0) and the stress drop (Δσ). This method is an advantage especially since if the source parameters are calculated from the time domain a full waveform inversion is needed, therefore this procedure facilitates the computation. Besides, the moment magnitude (Mw) can be calculated from the seismic moment and, in turn, the local magnitude (ML) can be obtained by using an algorithm that matches different ranges of moment magnitude with their corresponding local magnitude. In the present thesis, small to moderate earthquakes in Northern Sweden have been used to develop a code that calculates the source parameters through the fitting of five different spectral models and, this way, discerns which model obtains the best determination of the parameters. These models have been chosen in a way that we can also extract information about the attenuation. The different models are; the Brune spectral model, Boatwright spectral model, Boatwright spectral model with a fixed fall-off rate, a general form of the spectral model with quality factor equal to 1000 and a general form of the spectral model with quality factor equal to 600. Among these models, the Boatwright model with fixed fall-off rate equal to 2, has been found to give the best fit to the data used in this thesis. This might be due to the regional conditions which are the low attenuation in the crust of northern Fennoscandia and the short hypocentral distances of the studied earthquakes. The earthquakes studied in the present thesis have shown a range of magnitudes from ML 4.2 to -0.2 with radius of an assumed circular fault ranging from 269 m to 66 m.

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Ho, Xuan Hieu. "On multifractality, Schwarzian derivative and asymptotic variance of whole-plane SLE." Thesis, Orléans, 2016. http://www.theses.fr/2016ORLE2060/document.

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Soit f une instance du whole-plane $\SLE_\kappa$ : on sait que pour certaines valeurs de κ, p les moments dérivés $\mathbb{E}(\vert f'(z) \vert^p)$ peuvent être écrits sous une forme fermée, étude qui a permis de mettre au jour une nouvelle phase du spectre des moyennes intégrales. Le but de cette thèse est une étude des moments généralisés $\frac{\vert f'(z) \vert^p}{\vert f(z) \vert^q}$ : cette étude permet de confirmer la structure algébrique riche du whole-plane SLE. On montre que les formes fermées des moments mixtes $\mathbb{E}\big(\frac{\vert f'(z) \vert^p}{\vert f(z) \vert^q}\big)$ apparaissent sur une famille dénombrable de paraboles du plan (p, q), en étendant les équations de Beliaev-Smirnov à ce cas. Nous introduisons également le spectre généralisé β(p, q; κ), correspondant au comportement asymptotiques des moyennes intégrales mixtes. Le spectre généralisé moyen du whole-plane SLE prend quatre formes possibles, séparés par cinq séparatrices dans $\R^2$. Nous proposons également une approche semblable pour la dérivée Schwarziene S(f)(z) de l’application de SLE. Les calculs sur les équations de Beliaev-Smirnov d’une certaine générale forme de moment mène à une formulation explicite de $\mathbb{E}(S(f)(z))$ . Nous étudions finalement la variance asymptotique de McMullen et démontrons une relation entre la croissance infinitésimale du spectre de la moyenne intégrale et la variance asymptotique pour SLE₂
Let f an instance of the whole-plane $\SLE_\kappa$ conformal map from the unit disk D to the slit plane: We know that for certain values of κ, p the derivative moments $\mathbb{E}(\vert f'(z) \vert^p)$ can be written in a closed form, study that has updated a new phase of the integral means spectrum. The goal of this thesis is a study on generalized moments $\frac{\vert f'(z) \vert^p}{\vert f(z) \vert^q}$ : ΒββThis study permit confirm the rich algebraic structure of the whole-plane version of SLE. It will be showed that closed forms of the mixed moments E mixtes $\mathbb{E}\big(\frac{\vert f'(z) \vert^p}{\vert f(z) \vert^q}\big)$ can be obtained on a countable family of parabolas in the moment plane (p, q), by extending the so-called Beliaev–Smirnov equation to this case. We also introduce the generalized integral means spectrum, β(p, q; κ), corresponding to the singular behavior of the mixed moments. The average generalized spectrum of whole-plane SLE takes four possible forms, separated by five phase transition lines in $\R^2$. We also propose a similar approach for the Schwarzian derivative S(f)(z) of SLE maps. Computations on the Beliaev–Smirnov equation of a certain general form of moment lead to an explicit formula of $\mathbb{E}(S(f)(z))$ . We finally study the McMullen asymptotic variance and prove a relation between the infinitesimal growth of the integral mean spectrum and the asymptotic variance in an expectation sense for SLE₂

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Skalka, Miroslav. "Analýza vlivu mechanického momentu asynchronního stroje na sycení magnetického obvodu." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-233534.

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e main goal of this thesis is mechanical torque analysis of induction machine based on magnetic circuit saturation, oversaturated areas classification and the possibility of oversaturated areas reduction of their influence on machine properties. Whole problem is solved by finite element method in ANSYS program. Work is divided into the description and creating of electromagnetic model, a method of the induction machine equivalent circuit parameters determination, the electromagnetic field calculation by finite element method, experimental measurement using LabVIEW program with measurement accessories (PCIe card National Instruments), data processing program in DIAdem, results analysis of calculations in terms of magnetic circuit saturation, the influence of magnetic circuit material based on electromagnetic field distribution and the magnetic flux density along the air gap including spectral analysis using MATLAB and the electromagnetic torque and its parasitic torque components calculation.

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Ashbrook, Sharon Elizabeth. "New NMR techniques for the study of quadrupolar nuclei." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342238.

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Blomqvist, Anders. "A convex optimization approach to complexity constrained analytic interpolation with applications to ARMA estimation and robust control." Doctoral thesis, Stockholm, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-117.

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Díaz, Caballero Elena. "Efficient analysis and design of devices in Substrate Integrated Waveguide (SIW) technology." Doctoral thesis, Universitat Politècnica de València, 2013. http://hdl.handle.net/10251/34627.

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Para abordar el análisis de estas estructuras de forma altamente eficiente, se pretenden utilizar dos enfoques distintos, que llevarían a dos técnicas distintas y eficientes, pero cada una de ellas con sus ventajas e inconvenientes respecto de la otra, que podremos concluir una vez finalizado el trabajo de investigación. Por un lado, se pretende utilizar el Método de los Momentos, una técnica numérica que convierte las ecuaciones integrales de un problema electromagnético en un sistema linear, expandiendo la magnitud desconocida usando un conjunto de funciones con coeficientes desconocidos. Al forzar las condiciones de contorno, en este caso de potencial eléctrico, en un determinado número de puntos, se obtiene un sistema linear de ecuaciones que será resuelto numéricamente. Por otro lado, según el segundo enfoque, pretende utilizar una expansión en modos cilíndricos del campo, tanto incidente como dispersado. Dada la geometría circular de las vías éstas pueden ser caracterizadas de forma analítica mediante espectros circulares. Posteriormente se resolverá el acoplo entre las vías mediante el método de [1] pero generalizado al caso de objetos inmersos en un medio dieléctrico infinito, y se desarrollará un nuevo método de acoplo modal entre modos cilíndricos y modos guiados proyectando las ecuaciones del acoplo modal tanto sobre modos cilíndricos como sobre modos guiados para evitar las singularidades que aparecen con el método de de [2] cuando los planos de referencia están muy próximos al objeto dispersor. Por tanto, esta técnica caracterizará las vías de forma analítica y resolverá las integrales del acoplo de modos mediante la transformada rápida de Fourier. Para aumentar más aún la eficiencia de ambos métodos se evitará repetir los cálculos para cada punto en frecuencia, y se implementará la técnica de barrido rápido en frecuencia similar descrita en [3], adaptándola al caso particular de cada método de análisis, aunque se prevé que quizá dicho procedimiento sea más difícil de implementar en el segundo método. Se espera que ambas técnicas puedan proporcionar unos tiempos de computación inferiores a los del software comercial de análisis electromagnético más habitual (i.e. HFSS), y también inferiores a otros métodos de análisis recientemente aparecidos en la bibliografía técnica ([4],[5],[6]). En concreto, se espera que los tiempos de computación para barrido discreto en frecuencia sea inferior con el segundo método ya que usa únicamente expresiones analíticas y transformada rápida de Fourier, pero, dado que el primer método es más susceptible de realizar barrido rápido en frecuencia, éste puede ser muy útil a la hora de realizar muchos análisis consecutivos. Una vez se disponga de métodos eficientes para el análisis de dispositivos SIW, se abordará el diseño de varios dispositivos pasivos en esta tecnología (filtros de diferentes topologías, diplexores, multiplexores, híbridos, acopladores, etc.). Como se dispone de una vasta experiencia en el grupo de investigación en el diseño de dispositivos en guía de onda rectangular, se puede como primera aproximación realizar el diseño en guía, y luego transformar esta estructura guiada en otra en tecnología SIW mediante unas reglas empíricas que relacionan ambas tecnologías [7]. Posteriormente se debe ajustar el diseño en el dispositivo SIW ya que estas reglas empíricas no consiguen que la respuesta sea idéntica a la del dispositivo guiado original, principalmente debido al hecho de que los irises rectangulares de la guía son transformados en vías metalizadas con geometría circular, no rectangular. Para minimizar este ajuste, se diseñará el dispositivo guiado con irises con esquinas redondeadas en la cavidad (método de [8] pero con un simulador más eficiente [9]), haciendo que el radio de esas esquinas redondeadas coincida con el de las vías metalizadas que se van a utilizar en el dispositivo SIW. Esto permitirá [...] (Ver documento anexo)
Díaz Caballero, E. (2013). Efficient analysis and design of devices in Substrate Integrated Waveguide (SIW) technology [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/34627
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Kratz, Marie. "Some contributions in probability and statistics of extremes." Habilitation à diriger des recherches, Université Panthéon-Sorbonne - Paris I, 2005. http://tel.archives-ouvertes.fr/tel-00239329.

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Chen, Yu-Tang, and 陳于堂. "Analysis of Frequency Selective Surfacesby Spectral Moment Method." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/36712512285515443285.

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碩士
國立臺灣大學
應用力學研究所
94
Frequency selective surfaces (FSSs) have inspired great interest because of its filtering property. In general, FSSs comprise periodically arranged metallic patch elements or aperture elements within a metallic screen. The patches exhibit total reflection while the apertures exhibit total transmission in the resonant region. FSSs have widespread applications over much of electromagnetic spectrum. In the microwave region, FSSs can be utilized in reflector antennas, radome design, microwave monolithic circuit (MMIC) and beam controller. In the infrared region, the FSS is used as polarizers, beam splitters, laser and multiband IR filter. RFID tags, tunable filters, dichroic sub-reflectors, waveguide controlled coupling, reflective lens arrays, and single- and multi-mode array antennas are can be made by FSSs. Recently, metamaterials such as artificial magnetic conductors or left-handed materials also can be realized by periodic structures. The formulation is described as follows. When incident field propagate through an FSS, and this causes a surface current to be induced on the conducting screens, which in turn, radiate scatter field. Applying boundary condition, we can obtain electric field integral equation (EFIE). Because of periodicity of FSSs, we can utilize Floquet’s theorem to discretize integral equation. We use moment method to solve the induced current. We apply conjugate gradient method and fast Fourier transform for more computational efficiency. Finally, the reflection and transmission coefficient can be obtained from total reflected field and transmitted field, respectively.

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Yu-Tang, Chen. "Analysis of Frequency Selective Surfaces by Spectral Moment Method." 2006. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2607200610522800.

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VU, NGOC San. "Systèmes intégrables semi-classiques: du local au global." Habilitation à diriger des recherches, 2003. http://tel.archives-ouvertes.fr/tel-00007113.

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Ce mémoire a pour but de présenter un panorama des recherches que j'ai effectuées depuis la soutenance de ma thèse en 1998. J'en ai également profité pour réordonner mes résultats et émailler le texte de réflexions parfois nouvelles afin de tenter de combiner l'introduction au sujet avec la synthèse de mes recherches. Il sera question de systèmes hamiltoniens complètement intégrables, de leur étude locale, de leurs singularités, de leurs aspects globaux et de certains liens qu'il entretiennent avec les variétés toriques, tout ceci du point de vue de la mécanique classique ainsi que de celui de leur quantification semi-classique. Une étude détaillée des singularités dites non-dégénérées sera présentée.

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Maneira, Rúben Filipe Brás. "Análise comparativa de dimensionamento de um edifício de vários pisos com base no EC3 e EC3+EC8." Master's thesis, 2018. http://hdl.handle.net/10316/84880.

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Dissertação de Mestrado Integrado em Engenharia Civil apresentada à Faculdade de Ciências e Tecnologia
Structures are exposed to the various actions during its useful life, of which seismic action plays a relevant role. The importance of this action is from general knowledge, however it is impossible to predict the instant that occurs and its intensity. Therefore, it is essential that this action be properly considered while the projects of the structures located in areas of medium and high seismicity are made, otherwise it can have serious consequences, such as loss of human life, collapse of structures and high economic losses.This dissertation is based on the mentioned above, which is focused on a parametric study of the design of a building with metallic and composite structure, belonging to the high ductility class (DCH), considering three different structural configurations (three, six and nine floors), subjected to different levels of seismic intensity (null, medium and high). The structure takes advantage of a system of Moment Resisting Frames to resist horizontal actions. The design was carried out on the basis of the current European standards, Eurocode 0, Eurocode 1, Eurocode 3 and Eurocode 8. Structural analysis by the response-spectrum method was performed using the Autodesk® ROBOT ™ Structural Analysis Professional software. Regarging the cross sections strength verification of the structural elements, the SemiComp Member Design worksheet and the LTBeam software were used for the buildings in which seismic action was considered null. For the buildings dimensioned considering the seismic action, an Excel spreadsheet was created to verify the cross sections.With this work it is intended to evaluate the amount of steel required for each solution, which allows a direct comparison of the cost increment of the metallic and mixed structures with the increase of floors number and seismic intensity.
As estruturas encontram-se expostas a diversas ações durante o seu período de vida útil, das quais a ação sísmica pode assumir um papel condicionante. A importância desta ação é bem conhecida; no entanto, é impossível prever o instante em que ocorre e a sua intensidade. Torna-se por isso fundamental que a ação sísmica seja devidamente considerada aquando da realização dos projetos das estruturas situadas em zonas de média e elevada sismicidade; caso contrário, pode gerar graves consequências, como perda de vidas humanas, deformações permanentes ou até o colapso das estruturas, provocando assim elevadas perdas a nível económico.Esta dissertação enquadra-se no tema referido acima, sendo que esta contempla um estudo paramétrico relativo ao dimensionamento de um edifício em estrutura metálica e mista, pertencente à classe de ductilidade alta (DCH), que tira partido de um sistema de pórticos para resistir às ações horizontais, com três diferentes configurações em termos de altura (três, seis e nove pisos) e sujeitas a diferentes níveis de intensidade sísmica (nula, média e elevada). O dimensionamento foi realizado com base nas normas Europeias em vigor, o Eurocódigo 0, Eurocódigo 1, Eurocódigo 3 e o Eurocódigo 8. Para a análise das estruturas recorreu-se a uma análise modal por espetro de resposta, utilizando o software Autodesk® ROBOT™ Structural Analysis Professional. No que diz respeito à verificação da resistência das secções transversais dos elementos estruturais, foi utilizada a folha de cálculo SemiComp Member Design, e ao software LTBeam para os edifícios em que se considerou a ação sísmica nula. Relativamente aos edifícios dimensionados sujeitos à ação sísmica, foi criada uma folha de cálculo em excel para a verificação das secções transversais. Com a realização desta dissertação pretende-se avaliar a quantidade de aço necessária associada a cada solução, permitindo assim a comparação direta do incremento de custo das estruturas metálicas e mistas com o aumento do número de pisos e de intensidade sísmica.

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Dissertations / Theses on the topic 'Spectral moments analysis'

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