Relevant bibliographies by topics / Spectral moments analysis

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  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Spectral moments analysis'

Author: Grafiati
Published: 4 June 2021
Last updated: 1 February 2022

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Journal articles on the topic "Spectral moments analysis"

1

KOUSSOULAS, NICK T. "SPECTRAL MOMENTS AND THE ANALYSIS OF CHAOTIC SYSTEMS." International Journal of Bifurcation and Chaos 11, no. 07 (July 2001): 2051–59. http://dx.doi.org/10.1142/s0218127401003140.

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The simplicity of structure of chaotic systems, combined with the richness of their output, inspires their use in modeling efforts. On the other hand, the difficulty of their analysis warrants approximation methods, especially since the absence, by definition, of well-defined limit sets prohibits, in general, a meaningful linearization. In this work we present some results, which can support a methodology founded on spectral analysis for approximating chaotic systems via stochastic linear systems. The main contribution is the use of spectral moments for identifying the location of embedded limit cycles and the spectrum-based validation of approximations.
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Rosenbauer, Kimberly, Kerrie Obert, and Robert Allen Fox. "Spectral moments analysis of stops in tracheoesophageal speakers." Journal of the Acoustical Society of America 111, no. 5 (2002): 2480. http://dx.doi.org/10.1121/1.4778617.

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Tong, Fang, and Zhang Tianshu. "Calculating response spectral moments by complex modal analysis." Acta Mechanica Sinica 5, no. 2 (May 1989): 159–66. http://dx.doi.org/10.1007/bf02489141.

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Jun, Seockhee, and Jun-Bum Park. "Development of Empirical Formulas for Approximate Spectral Moment Based on Rain-Flow Counting Stress-Range Distribution." Journal of Ocean Engineering and Technology 35, no. 4 (August 31, 2021): 257–65. http://dx.doi.org/10.26748/ksoe.2021.014.

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Many studies have been performed to predict a reliable and accurate stress-range distribution and fatigue damage regarding the Gaussian wide-band stress response due to multi-peak waves and multiple dynamic loads. So far, most of the approximation models provide slightly inaccurate results in comparison with the rain-flow counting method as an exact solution. A step-by-step study was carried out to develop new approximate spectral moments that are close to the rain-flow counting moment, which can be used for the development of a fatigue damage model. Using the special parameters and bandwidth parameters, four kinds of parameter-based combinations were constructed and estimated using the R-squared values from regression analysis. Based on the results, four candidate empirical formulas were determined and compared with the rain-flow counting moment, probability density function, and root mean square (RMS) value for relative distance. The new approximate spectral moments were finally decided through comparison studies of eight response spectra. The new spectral moments presented in this study could play an important role in improving the accuracy of fatigue damage model development. The present study shows that the new approximate moment is a very important variable for the enhancement of Gaussian wide-band fatigue damage assessment.
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El-Kader, M. S. A., and G. Maroulis. "Moment analysis in collision-induced absorption: Determination of a single parameter empirical model for the induced dipole moment of He-Ar gas mixtures." Journal of Computational Methods in Sciences and Engineering 21, no. 3 (August 2, 2021): 577–92. http://dx.doi.org/10.3233/jcm-200043.

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We present a method for the construction of a one-adjustable-parameter empirical model for the induced dipole moment. The method is based on classical physics principles and relies on the first three spectral moments of the collision-induced absorption spectra at various temperatures and new interaction potentials. In this work it is applied to the spectra of He-Ar mixtures. Our values are in good agreement with the available ab initio data. The profiles calculated with these models at various temperatures are in excellent agreement with experiment.
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SHEN, JUN, WEI SHEN, and DANFEI SHEN. "ON GEOMETRIC AND ORTHOGONAL MOMENTS." International Journal of Pattern Recognition and Artificial Intelligence 14, no. 07 (November 2000): 875–94. http://dx.doi.org/10.1142/s0218001400000581.

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Moments are widely used in pattern recognition, image processing, computer vision and multiresolution analysis. To clarify and to guide the use of different types of moments, we present in this paper a study on the different moments and compare their behavior. After an introduction to geometric, Legendre, Hermite and Gaussian–Hermite moments and their calculation, we analyze at first their behavior in spatial domain. Our analysis shows orthogonal moment base functions of different orders having different number of zero-crossings and very different shapes, therefore they can better separate image features based on different modes, which is very interesting for pattern analysis and shape classification. Moreover, Gaussian–Hermite moment base functions are much more smoothed, they are thus less sensitive to noise and avoid the artifacts introduced by window function discontinuity. We then analyze the spectral behavior of moments in frequency domain. Theoretical and numerical analyses show that orthogonal Legendre and Gaussian–Hermite moments of different orders separate different frequency bands more effectively. It is also shown that Gaussian–Hermite moments present an approach to construct orthogonal features from the results of wavelet analysis. The orthogonality equivalence theorem is also presented. Our analysis is confirmed by numerical results, which are then reported.
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Tjaden, Kris, and Greg S. Turner. "Spectral Properties of Fricatives in Amyotrophic Lateral Sclerosis." Journal of Speech, Language, and Hearing Research 40, no. 6 (December 1997): 1358–72. http://dx.doi.org/10.1044/jslhr.4006.1358.

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Spectral characteristics of word initial /s/and /∫/produced by individuals with amyotrophic lateral sclerosis (ALS) and healthy controls were quantified using spectral moment analysis. Coefficients of the first four moments were used as descriptive indices of central tendency, spread of energy, shape, and peakedness. The relationship between select moment coefficients and consonant precision ratings was investigated to explore potential perceptual correlates of the acoustic measures. To examine whether spectra for ALS and healthy speakers were influenced similarly by context, first moment coefficients for three occurrences of /s/in “some” were inspected for individual speakers. Select moment coefficients also were compared to hand-derived spectral measures for a subset of speakers. Results suggest articulatory differences in /s/and /∫/for the present group of ALS speakers and healthy controls, as indexed by between-group differences in first moment coefficients. A linear function accounted for a significant proportion of the variance in the relationship between consonant precision ratings and the frequency difference between the first moment for /s/and /∫/. Inspection of first moment coefficients for multiple occurrences of /s/in “some” suggests context influences the first moment in a similar manner for ALS and healthy speakers. The subanalysis comparing moment coefficients and hand-derived spectral measures revealed both similarities and differences in the manner the two measurement techniques reflect spectral shape.
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Osipov, Andrey. "Inverse spectral problem for Jacobi operators and Miura transformation." Concrete Operators 8, no. 1 (January 1, 2021): 77–89. http://dx.doi.org/10.1515/conop-2020-0116.

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Abstract We study a Miura-type transformation between Kac - van Moerbeke (Volterra) and Toda lattices in terms of the inverse spectral problem for Jacobi operators, which appear in the Lax representation for such systems. This inverse problem method, which amounts to reconstruction of the operator from the moments of its Weyl function, can be used in solving initial-boundary value problem for both systems. It is shown that the Miura transformation can be easily described in terms of these moments. Using this description we establish a bijection between the Volterra lattices and the class of Toda lattices which is characterized by positivity of Jacobi operators in their Lax representation. Also, we discuss an implication of the latter result to the spectral theory.
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Viswanathan, A., V. A. Subramanian, and D. Kumar. "Location-based fatigue damage assessment on an FPSO by the spectral analysis method." MATEC Web of Conferences 272 (2019): 01019. http://dx.doi.org/10.1051/matecconf/201927201019.

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Floating production storage and offloading ships (FPSOs) are offshore platforms positioned at a location and operating at different loading conditions and corresponding draughts. Due to their static location, they get subjected to continuous fluctuating loads due to the sea environment. For these reasons the fatigue damage prediction of an FPSO is essential. The emphasis of this study is on the effect of fatigue damage at critical joints of critical structural members under the influence of vertical and horizontal bending in isolation and combination. The method considers an FPSO of 320m length for a case study, selecting a total of fourteen such structural member locations along the periphery at its midship section. The analysis considers two necessary loading conditions namely, fully loaded and ballast condition. The study uses spectral fatigue analysis method wherein the bending moment transfer function generates the stress transfer function, which in turn helps to generate the power spectral density function. Combining the spectral moments with Palmgren-Miner rule gives the cumulative fatigue damage of the FPSO. The results provide an insight into the variation in fatigue damage concerning the location of the structural member under the influence of vertical and horizontal bending moments.
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Galbraith, Gary C., and Eugene H. Wong. "Moment Analysis of Eeg Amplitude Histograms and Spectral Analysis: Relative Classification of Several Behavioral Tasks." Perceptual and Motor Skills 76, no. 3 (June 1993): 859–66. http://dx.doi.org/10.2466/pms.1993.76.3.859.

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Previous studies indicate that EEG amplitude probability density functions are Gaussian (normal) during rest and non-Gaussian during performance of mental tasks. In the present study we compared measures of normality, including higher central moments (e.g., skewness, kurtosis) and relative spectral power, to classify data sampled from several different behavioral tasks (resting eyes closed and mental arithmetic). Analysis shows significant classification in 22 of 25 subjects, based upon a total of 46 EEG variables. However, only two of these variables involved Gaussian properties of the amplitude distribution. Relative spectral power, on the other hand, contributed 33 predictor variables in delta, theta, alpha, and beta frequency bands (alpha was the best single predictor). These results lend support to studies demonstrating the robustness of EEG relative spectra but cast doubt upon the utility of Gaussian patterns in EEG amplitude distributions as predictors of behavioral states.
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Dissertations / Theses on the topic "Spectral moments analysis"

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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  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 . 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  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 , where , is a consistent estimator of the . We consider , where , 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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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/, /θ/, /s/, and /ʃ/) 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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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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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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Books on the topic "Spectral moments analysis"

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Koli︠a︡da, S. F. Dynamics and numbers: A special program, June 1-July 31, 2014, Max Planck Institute for Mathematics, Bonn, Germany : international conference, July 21-25, 2014, Max Planck Institute for Mathematics, Bonn, Germany. Edited by Max-Planck-Institut für Mathematik. Providence, Rhode Island: American Mathematical Society, 2016.

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2

An overdetermined system for improved autocorrelation based spectral moment estimator performance. Clemson, SC: Electrical and Computer Engineering Dept., Clemson University, 1996.

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Center, Langley Research, ed. An overdetermined system for improved autocorrelation based spectral moment estimator performance. Hampton, VA: National Aeronautics and Space Administration, Langley Research Center, 1996.

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Book chapters on the topic "Spectral moments analysis"

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Obata, Nobuaki. "Analytic Theory of Moments." In Spectral Analysis of Growing Graphs, 63–77. Singapore: Springer Singapore, 2017. http://dx.doi.org/10.1007/978-981-10-3506-7_5.

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Somsen, Oscar J. G., Rienk van Grondelle, and Herbert van Amerongen. "Spectral Moments Facilitate the Analysis of Circular Dichroism Spectra." In Photosynthesis: from Light to Biosphere, 263–66. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-009-0173-5_61.

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Moschini, Ugo, Paul Teeninga, Scott C. Trager, and Michael H. F. Wilkinson. "Parallel 2D Local Pattern Spectra of Invariant Moments for Galaxy Classification." In Computer Analysis of Images and Patterns, 121–33. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-23117-4_11.

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Huber, Josef Georg, Horst Schmidt-Böcking, and Bretislav Friedrich. "Walther Gerlach (1889–1979): Precision Physicist, Educator and Research Organizer, Historian of Science." In Molecular Beams in Physics and Chemistry, 119–61. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-63963-1_8.

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AbstractWalther Gerlach’s numerous contributions to physics include precision measurements related to the black-body radiation (1912–1916) as well as the first-ever quantitative measurement of the radiation pressure (1923), apart from his key role in the epochal Stern-Gerlach experiment (1921–1922). His wide-ranging research programs at the Universities of Tübingen, Frankfurt, and Munich entailed spectroscopy and spectral analysis, the study of the magnetic properties of matter, and radioactivity. An important player in the physics community already in his 20s and in the German academia in his later years, Gerlach was appointed, on Werner Heisenberg’s recommendation, Plenipotentiary for nuclear research for the last sixteen months of the existence of the Third Reich. He supported the effort of the German physicists to achieve a controlled chain reaction in a uranium reactor until the last moments before the effort was halted by the Allied Alsos Mission. The reader can find additional discussion of Gerlach’s role in the supplementary material provided with the online version of the chapter on SpringerLink. After returning from his detention at Farm Hall, he redirected his boundless elan and determination to the reconstruction of German academia. Among his high-ranking appointments in the Federal Republic were the presidency of the University of Munich (1948–1951) and of the Fraunhofer Society (1948–1951) as well as the vice-presidency of the German Science Foundation (1949–1961) and the German Physical Society (1956–1957). As a member of Göttinger Achtzehn, he signed the Göttingen Declaration (1957) against arming the Bundeswehr with nuclear weapons. Having made history in physics, Gerlach became a prolific writer on the history of physics. Johannes Kepler was his favorite subject and personal hero—as both a scientist and humanist.
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Múnera, Nicolás, Javier Almeida, Charlems Álvarez, Nelson Velasco, and Eduardo Romero. "Autism Spectrum Disorders (ASD) Characterization in Children by Decomposing MRI Brain Regions with Zernike Moments." In Processing and Analysis of Biomedical Information, 42–53. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-13835-6_6.

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Berezansky, Yu M. "Spectral Theory of the Infinite Block Jacobi Type Normal Matrices, Orthogonal Polynomials on a Complex Domain, and the Complex Moment Problem." In Modern Analysis and Applications, 37–50. Basel: Birkhäuser Basel, 2009. http://dx.doi.org/10.1007/978-3-7643-9921-4_4.

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Pommé, S., and J. Keightley. "Count Rate Estimation of a Poisson Process: Unbiased Fit versus Central Moment Analysis of Time Interval Spectra." In ACS Symposium Series, 316–34. Washington, DC: American Chemical Society, 2006. http://dx.doi.org/10.1021/bk-2007-0945.ch023.

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Schuchmann, Simone. "Analysis: Reconstruction of $$\mathrm{K}^\mathrm{0}_\mathrm{s}$$ and $$\Lambda (\overline{\Lambda })$$ Transverse Momentum Spectra." In Modification of K0s and Lambda(AntiLambda) Transverse Momentum Spectra in Pb-Pb Collisions at √sNN = 2.76 TeV with ALICE, 71–116. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-43458-2_4.

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Polyak, Ilya. "Second Moments of Rain." In Computational Statistics in Climatology. Oxford University Press, 1996. http://dx.doi.org/10.1093/oso/9780195099997.003.0010.

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The first part of this chapter presents a description of the GATE rain rate data (Polyak and North, 1995), its two-dimensional spectral and correlation characteristics, and multivariate models. Such descriptions have made it possible to show the concentration of significant power along the frequency axis in the spatial-temporal spectra; to detect a diurnal cycle (a range of variation of which is about 3.4 to 5.4 mm/hr); to study the anisotropy (as the result of the distinction between the north-south and east-west transport of rain) of spatial rain rate fields; to evaluate the scales of the distinction between second-moment estimates associated with ground and satellite samples; to determine the appropriate spatial and temporal scales of the simple linear stochastic models fitted to averaged rain rate fields; and to evaluate the mean advection velocity of the rain rate fluctuations. The second part of this chapter (adapted from Polyak et al., 1994) is mainly devoted to the diffusion of rainfall (from PRE-STORM experiment) by associating the multivariate autoregressive model parameters and the diffusion equation coefficients. This analysis led to the use of rain data to estimate rain advection velocity as well as other coefficients of the diffusion equation of the corresponding field. The results obtained can be used in the ground truth problem for TRMM (Tropical Rainfall Measuring Mission) satellite observations, for comparison with corresponding estimates of other sources of data (TOGA-COARE, or simulated by physical, models), for generating multiple rain samples of any size, and in some other areas of rain data analysis and modeling. For many years, the GATE data base has served as the richest and most accurate source of rain observations. Dozens of articles presenting the results of the GATE rain rate data analysis and modeling have been published, and more continue to be released. Recently, a new, valuable set of rain data was produced as a result of the TOGA-COARE experiment. In a few years, it will be possible to obtain satellite (TRMM) rain information, and a rain statistical description will be needed in the analysis of the observations obtained on an irregular spatial and temporal grid.
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Regueira Fernández, Xosé Luís, and María José Ginzo. "A crosslinguistic study of voiceless fricative sibilants in Galician and European Portuguese." In Romance Phonetics and Phonology, 62–76. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198739401.003.0004.

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This study examines the sibilant fricatives produced by seventeen Galician and twenty-two Portuguese speakers. Galician and Portuguese are closely related languages that present important continuities, although it is in their phonological and phonetic systems that they diverge most obviously. By means of the analysis of spectra and spectral moments, chiefly the spectral mean, postalveolar sibilants and front (alveolar or alveolo-dental) sibilants are differentiated in both Galician and Portuguese. Much variation has been found in front sibilant realizations among speakers and even between different realizations by the same speaker. This variation is especially striking among male Galician speakers, where it was possible to distinguish three different articulations, identified here as an apico-aveolar [s̺], a lamino-alveolar [s], and a lamino-dental [s̪] sibilant. The research results point to a loss of phonetic diversity on the Portuguese side of the political border, while in Galicia it is better preserved, although it is losing ground.
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Conference papers on the topic "Spectral moments analysis"

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Głaz, Waldemar, Tadeusz Bancewicz, Jean-Luc Godet, George Maroulis, Theodore E. Simos, and George Maroulis. "Induced Hyper-Rayleigh Spectra. Theoretical and Numerical Analysis of Spectral Moments." In COMPUTATIONAL METHODS IN SCIENCE AND ENGINEERING: Theory and Computation: Old Problems and New Challenges. Lectures Presented at the International Conference on Computational Methods in Science and Engineering 2007 (ICCMSE 2007): VOLUME 1. AIP, 2007. http://dx.doi.org/10.1063/1.2836109.

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Parihar, Yogendra, Saikat Dan, Karan Doshi, and Shivaji Ganesan Thirunaavukarasu. "Application of Direct Hydrodynamic Loads in Spectral Fatigue Analysis." In ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/omae2017-61907.

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It is common practice to employ direct calculation procedures for spectral based fatigue assessment. Numerical codes are used to compute direct hydrodynamic loads. There are several complexities and nuances associated with application of loads on finite element (FE) model. It is a computationally expensive task especially when a large number of cases need to be analyzed (for e.g. spectral fatigue analysis). The present paper outlines an approach to evaluate the stress transfer function based on the direct application of moments (vertical bending, horizontal bending and torsional moments) computed using a frequency-domain based sea-keeping code. Multi-point constraint (MPC) method is utilized for application of bending moment. The structural responses computed using direct application of the bending moments (Method 1) and the panel pressures (Method 2) are compared. The evaluated stress transfer function is used for spectral fatigue analysis. Overall, the present study provides a methodology for spectral fatigue assessment using direct application of bending moments.
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Gruszka, M., and A. Borysow. "Improved analysis of the spectral moments of CIA in N[sub 2] and CO[sub 2] gases." In The 13th international conference on spectral line shapes. AIP, 1997. http://dx.doi.org/10.1063/1.51898.

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Grunwald, Rudiger, and Martin Bock. "Spatio-Spectral Analysis and Encoding of Ultrashort Pulses with Higher-Order Statistical Moments." In CLEO 2007. IEEE, 2007. http://dx.doi.org/10.1109/cleo.2007.4452823.

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Abu-Mahfouz, Issam, Amit Banerjee, and Ma’moun Abu-Ayyad. "Fatigue Damage Diagnosis Using Statistical, Spectral, and Wavelet Analysis Techniques." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-66518.

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The objective of this work is to illustrate a comparative investigation into the signatures of crack initiation and propagation using vibration and displacement signals. Experimental tests were performed on low carbon steel specimen under fully reversed bending cycles in a cantilever support configuration. Accelerometer and displacement-sensor vibration signals were collected using a National Instrument data acquisition system. Several methods, such as statistical moments, FFT, Wavelets, and short-time-frequency analysis techniques, were used to analyze the collected signals. It was found that the wavelet analysis gave the most consistent patterns in tracking crack initiation and propagation. For the wavelet analysis, extensive comparative investigation was conducted to select the optimum combination of wavelet packets for crack detection and monitoring.
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Cui, Lei, Jia-nan Xu, Yong He, and Wei-liang Jin. "Fatigue Analysis on Key Components of Semi-Submersible Platform." In ASME 2010 29th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/omae2010-20973.

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Fatigue damage is one of the main reasons of the failure of Semi-Submersible platform. As the complex of random loading, it is difficult to analyze fatigue life accurately and determine the sensitivity of parameters. In this paper, the fatigue life on key-components of semi-submersible platform is analyzed with Spectral-based analysis method. Firstly, the stress responses of whole model platform under the random wave loads are calculated. The calculation results of whole model platform for cut-boundary interpolation are used in local model to calculate the key-component stress responses of local model. Generating the fatigue stress energy spectrum by scaling the wave energy spectrum and the complex fatigue stress transfer function in detail local model is described next. The stress response of short-term sea-state is assumed to obey Rayleigh distribution, and the spectral moments are calculated. Finally, the fatigue life of key components is analyzed according to S-N curve and Palmgren-Miner’s rule. The results show that the fatigue life of the connection meets the specification requirements, and the key components are the fatigue sensitive areas of semi-submersible platform.
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Elshafiey, Tarief M. F. "3-D Full Wave Analysis using Spectral Domain Method of Moments for a Ferrite Cross-Patch Antenna." In 2007 National Radio Science Conference. IEEE, 2007. http://dx.doi.org/10.1109/nrsc.2007.371345.

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Morris, Eric, Norman Allyn, and Michael Isaacson. "Dynamic Analysis of Long Floating Structures in Waves." In ASME 2004 23rd International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2004. http://dx.doi.org/10.1115/omae2004-51395.

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This paper describes a frequency domain dynamic analysis technique for calculating the response of long floating structures in waves. Due to the large dimensions of the structure, it is necessary to account for the correlation of wave forces along the structure length to accurately calculate the response. The sea surface is therefore modeled as short-crested and is described by a directional wave spectrum. The dynamic analysis technique uses a superposition principle in which the short-crested sea is composed of numerous harmonic wave components with different frequencies and directions of propagation and amplitudes calculated from the directional wave spectrum. Hydrodynamic coefficients are calculated using a 2-dimensional diffraction program. The structure is modeled using beam elements in the ANSYS finite element program and moorings are represented using spring elements. The response of the structure to each wave component is calculated in a series of harmonic analyses. Spectral analysis is used to calculate the variance of the responses in a given storm event. The responses of interest for a given exceedence probability are then determined. The covariance of the responses is calculated and coincident response combinations are produced based on the assumption that the responses have a multi-variate normal distribution. The magnitude of coincident responses is often of interest in structural design. For example, a member subject to bi-axial bending could be designed to have excess resistance if the maximum value of the orthogonal bending moments obtained from a dynamic analysis is used rather than the coincident bending moments.
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Olagnon, Michel, and Zakoua Gue´de´. "Parametric Rainflow Fatigue Damage for Some Power Spectra of Common Use." In ASME 2010 29th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/omae2010-20111.

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Rainflow counting is widely accepted as the method that is most suited to analysis of fatigue damage of materials submitted to irregular loading. Formulas such as the Wirsching-Light and the Dirlik one allow to take into account spectral shape and bandwidth in an empirical or semi-empirical manner to obtain a best estimate damage reduction of the rainflow counting with respect to the narrow-band approximation. However, if one considers parametric shape families of common use for the spectra, a more straightforward way is to make damage depend on the shape parameter of the family rather than on the spectral moments. We provide here such semi-empirical parametric formulas for the Jonswap, Wallops, Triangle and Power-tail families. In addition, the ICA formula allows us to extend the above formulas to the well-known bimodal spectral shape proposed by Ochi-Hubble.
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Karlsson, Kristian, Jan Carlsson, and Per-Simon Kildal. "Analysis of wires inside a reverberation chamber using the method of moments combined with spectral domain techniques and asymptotic extraction." In 2006 1st European Conference on Antennas and Propagation (EuCAP). IEEE, 2006. http://dx.doi.org/10.1109/eucap.2006.4585039.

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Reports on the topic "Spectral moments analysis"

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Author, Not Given. Source Spectra Analysis of SPE Phase I from Frequency-Domain Moment Tensor Inversion. Office of Scientific and Technical Information (OSTI), November 2017. http://dx.doi.org/10.2172/1407858.

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