To see the other types of publications on this topic, follow the link: MOMENTS METHOD.

Dissertations / Theses on the topic 'MOMENTS METHOD'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 dissertations / theses for your research on the topic 'MOMENTS METHOD.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.

1

Shin, Changmock. "Entropy Based Moment Selection in Generalized Method of Moments." NCSU, 2005. http://www.lib.ncsu.edu/theses/available/etd-06072005-112026/.

Full text
Abstract:
GMM provides a computationally convenient estimation method and the resulting estimator can be shown to be consistent and asymptotically normal under the fairly moderate regularity conditions. It is widely known that the information content in the population moment condition has impacts on the quality of the asymptotic approximation to finite sample behavior. This dissertation focuses on a moment selection procedure that leads us to choose relevant (asymptotically efficient and non-redundant) moment conditions in the presence of weak identification. The contributions of this dissertation can be characterized as follows: in the framework of linear model, (i) the concept of nearly redundant moment conditions is introduced and the connection between near redundancy and weak identification is explored; (ii) performance of RMSC(c) is evaluated when weak identification is a possibility but the parameter vector to be estimated is not weakly identified by the candidate set of moment conditions; (iii) performance of RMSC(c) is also evaluated when the parameter vector is weakly identified by the candidate set; (iv) a combined strategy of Stock and Yogo's (2002) test for weak identification and RMSC(c) is introduced and evaluated; (v) (i) and (ii) are extended to allow for nonlinear dynamic models. The subsequent simulation results support the analytical findings: when only a part of instruments in the set of possible candidates for instruments are relevant and the others are redundant given all or some of the relevant ones, RMSC(c) chooses all the relevant instruments with high probabilities and improves the quality of the post-selection inferences; when the candidates are in order of their importance, a combined strategy of Stock and Yogo's (2002) pretest and RMSC(c) improves the post-selection inferences, however it tends to select parsimonious models; when all the possible candidates are equally important, it seems that RMSC(c) does not provide any merits. However, in the last case, asymptotic efficiency and non-redundancy can be achieved by basing the estimation and inference on all the possible candidates.
APA, Harvard, Vancouver, ISO, and other styles
2

Lai, Yanzhao. "Generalized method of moments exponential distribution family." View electronic thesis (PDF), 2009. http://dl.uncw.edu/etd/2009-2/laiy/yanzhaolai.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Virk, Bikram. "Implementing method of moments on a GPGPU using Nvidia CUDA." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/33980.

Full text
Abstract:
This thesis concentrates on the algorithmic aspects of Method of Moments (MoM) and Locally Corrected Nyström (LCN) numerical methods in electromagnetics. The data dependency in each step of the algorithm is analyzed to implement a parallel version that can harness the powerful processing power of a General Purpose Graphics Processing Unit (GPGPU). The GPGPU programming model provided by NVIDIA's Compute Unified Device Architecture (CUDA) is described to learn the software tools at hand enabling us to implement C code on the GPGPU. Various optimizations such as the partial update at every iteration, inter-block synchronization and using shared memory enable us to achieve an overall speedup of approximately 10. The study also brings out the strengths and weaknesses in implementing different methods such as Crout's LU decomposition and triangular matrix inversion on a GPGPU architecture. The results suggest future directions of study in different algorithms and their effectiveness on a parallel processor environment. The performance data collected show how different features of the GPGPU architecture can be enhanced to yield higher speedup.
APA, Harvard, Vancouver, ISO, and other styles
4

Li, Tao. "3D Capacitance Extraction With the Method of Moments." Digital WPI, 2010. https://digitalcommons.wpi.edu/etd-theses/86.

Full text
Abstract:
In this thesis, the Method of Moments has been applied to calculate capacitance between two arbitrary 3D metal conductors or a capacitance matrix for a 3D multi-conductor system. Capacitance extraction has found extensive use for systems involving sets of long par- allel transmission lines in multi-dielectric environment as well as integrated circuit package including three-dimensional conductors located on parallel planes. This paper starts by reviewing fundamental aspects of transient electro-magnetics followed by the governing dif- ferential and integral equations to motivate the application of numerical methods as Method of Moments(MoM), Finite Element Method(FEM), etc. Among these numerical tools, the surface-based integral-equation methodology - MoM is ideally suited to address the prob- lem. It leads to a well-conditioned system with reduced size, as compared to volumetric methods. In this dissertation, the MoM Surface Integral Equation (SIE)-based modeling approach is developed to realize electrostatic capacitance extraction for 3D geometry. MAT- LAB is employed to validate its e?ciency and e?ectiveness along with design of a friendly GUI. As a base example, a parallel-plate capacitor is considered. We evaluate the accu- racy of the method by comparison with FEM simulations as well as the corresponding quasi-analytical solution. We apply this method to the parallel-plate square capacitor and demonstrate how far could the undergraduate result 0C = A ? "=d' be from reality. For the completion of the solver, the same method is applied to the calculation of line capacitance for two- and multi-conductor 2D transmission lines.
APA, Harvard, Vancouver, ISO, and other styles
5

Liang, Yitian. "Generalized method of moments : theoretical, econometric and simulation studies." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/36866.

Full text
Abstract:
The GMM estimator is widely used in the econometrics literature. This thesis mainly focus on three aspects of the GMM technique. First, I derive the prooves to study the asymptotic properties of the GMM estimator under certain conditions. To my best knowledge, the original complete prooves proposed by Hansen (1982) is not easily available. In this thesis, I provide complete prooves of consistency and asymptotic normality of the GMM estimator under some stronger assumptions than those in Hansen (1982). Second, I illustrate the application of GMM estimator in linear models. Specifically, I emphasize the economic reasons underneath the linear statistical models where GMM estimator (also referred to the Instrumental Variable estimator) is widely used. Third, I perform several simulation studies to investigate the performance of GMM estimator under different situations.
APA, Harvard, Vancouver, ISO, and other styles
6

McLeod, James William. "An investigation of the CDF-based method of moments." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0009/MQ34121.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Strydom, Willem Jacobus. "Recovery based error estimation for the Method of Moments." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/96881.

Full text
Abstract:
Thesis (MEng)--Stellenbosch University, 2015.
ENGLISH ABSTRACT: The Method of Moments (MoM) is routinely used for the numerical solution of electromagnetic surface integral equations. Solution errors are inherent to any numerical computational method, and error estimators can be effectively employed to reduce and control these errors. In this thesis, gradient recovery techniques of the Finite Element Method (FEM) are formulated within the MoM context, in order to recover a higher-order charge of a Rao-Wilton-Glisson (RWG) MoM solution. Furthermore, a new recovery procedure, based specifically on the properties of the RWG basis functions, is introduced by the author. These recovered charge distributions are used for a posteriori error estimation of the charge. It was found that the newly proposed charge recovery method has the highest accuracy of the considered recovery methods, and is the most suited for applications within recovery based error estimation. In addition to charge recovery, the possibility of recovery procedures for the MoM solution current are also investigated. A technique is explored whereby a recovered charge is used to find a higher-order divergent current representation. Two newly developed methods for the subsequent recovery of the solenoidal current component, as contained in the RWG solution current, are also introduced by the author. A posteriori error estimation of the MoM current is accomplished through the use of the recovered current distributions. A mixed second-order recovered current, based on a vector recovery procedure, was found to produce the most accurate results. The error estimation techniques developed in this thesis could be incorporated into an adaptive solver scheme to optimise the solution accuracy relative to the computational cost.
AFRIKAANSE OPSOMMING: Die Moment Metode (MoM) vind algemene toepassing in die numeriese oplossing van elektromagnetiese oppervlak integraalvergelykings. Numeriese foute is inherent tot die prosedure: foutberamingstegnieke is dus nodig om die betrokke foute te analiseer en te reduseer. Gradiënt verhalingstegnieke van die Eindige Element Metode word in hierdie tesis in die MoM konteks geformuleer. Hierdie tegnieke word ingespan om die oppervlaklading van 'n Rao-Wilton-Glisson (RWG) MoM oplossing na 'n verbeterde hoër-orde voorstelling te neem. Verder is 'n nuwe lading verhalingstegniek deur die outeur voorgestel wat spesifiek op die eienskappe van die RWG basis funksies gebaseer is. Die verhaalde ladingsverspreidings is geïmplementeer in a posteriori fout beraming van die lading. Die nuut voorgestelde tegniek het die akkuraatste resultate gelewer, uit die groep verhalingstegnieke wat ondersoek is. Addisioneel tot ladingsverhaling, is die moontlikheid van MoM-stroom verhalingstegnieke ook ondersoek. 'n Metode vir die verhaling van 'n hoër-orde divergente stroom komponent, gebaseer op die verhaalde lading, is geïmplementeer. Verder is twee nuwe metodes vir die verhaling van die solenodiale komponent van die RWG stroom deur die outeur voorgestel. A posteriori foutberaming van die MoM-stroom is met behulp van die verhaalde stroom verspreidings gerealiseer, en daar is gevind dat 'n gemengde tweede-orde verhaalde stroom, gebaseer op 'n vektor metode, die beste resultate lewer. Die foutberamingstegnieke wat in hierdie tesis ondersoek is, kan in 'n aanpasbare skema opgeneem word om die akkuraatheid van 'n numeriese oplossing, relatief tot die berekeningskoste, te optimeer.
APA, Harvard, Vancouver, ISO, and other styles
8

Arvas, Serhend. "A method of moments analysis of microstructured optical fibers." Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2009. http://wwwlib.umi.com/cr/syr/main.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

CUNHA, JOAO MARCO BRAGA DA. "ESTIMATING ARTIFICIAL NEURAL NETWORKS WITH GENERALIZED METHOD OF MOMENTS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2015. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=26922@1.

Full text
Abstract:
PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
PROGRAMA DE EXCELENCIA ACADEMICA
As Redes Neurais Artificiais (RNAs) começaram a ser desenvolvidas nos anos 1940. Porém, foi a partir dos anos 1980, com a popularização e o aumento de capacidade dos computadores, que as RNAs passaram a ter grande relevância. Também nos anos 1980, houve dois outros acontecimentos acadêmicos relacionados ao presente trabalho: (i) um grande crescimento do interesse de econometristas por modelos não lineares, que culminou nas abordagens econométricas para RNAs, no final desta década; e (ii) a introdução do Método Generalizado dos Momentos (MGM) para estimação de parâmetros, em 1982. Nas abordagens econométricas de RNAs, sempre predominou a estimação por Quasi Máxima Verossimilhança (QMV). Apesar de possuir boas propriedades assintóticas, a QMV é muito suscetível a um problema nas estimações em amostra finita, conhecido como sobreajuste. O presente trabalho estende o estado da arte em abordagens econométricas de RNAs, apresentando uma proposta alternativa à estimação por QMV que preserva as suas boas propriedades assintóticas e é menos suscetível ao sobreajuste. A proposta utiliza a estimação pelo MGM. Como subproduto, a estimação pelo MGM possibilita a utilização do chamado Teste J para verifificar a existência de não linearidade negligenciada. Os estudos de Monte Carlo realizados indicaram que as estimações pelo MGM são mais precisas que as geradas pela QMV em situações com alto ruído, especialmente em pequenas amostras. Este resultado é compatível com a hipótese de que o MGM é menos suscetível ao sobreajuste. Experimentos de previsão de taxas de câmbio reforçaram estes resultados. Um segundo estudo de Monte Carlo apontou boas propriedades em amostra finita para o Teste J aplicado à não linearidade negligenciada, comparado a um teste de referência amplamente conhecido e utilizado. No geral, os resultados apontaram que a estimação pelo MGM é uma alternativa recomendável, em especial no caso de dados com alto nível de ruído.
Artificial Neural Networks (ANN) started being developed in the decade of 1940. However, it was during the 1980 s that the ANNs became relevant, pushed by the popularization and increasing power of computers. Also in the 1980 s, there were two other two other academic events closely related to the present work: (i) a large increase of interest in nonlinear models from econometricians, culminating in the econometric approaches for ANN by the end of that decade; and (ii) the introduction of the Generalized Method of Moments (GMM) for parameter estimation in 1982. In econometric approaches for ANNs, the estimation by Quasi Maximum Likelihood (QML) always prevailed. Despite its good asymptotic properties, QML is very prone to an issue in finite sample estimations, known as overfiting. This thesis expands the state of the art in econometric approaches for ANNs by presenting an alternative to QML estimation that keeps its good asymptotic properties and has reduced leaning to overfiting. The presented approach relies on GMM estimation. As a byproduct, GMM estimation allows the use of the so-called J Test to verify the existence of neglected nonlinearity. The performed Monte Carlo studies indicate that the estimates from GMM are more accurate than those generated by QML in situations with high noise, especially in small samples. This result supports the hypothesis that GMM is susceptible to overfiting. Exchange rate forecasting experiments reinforced these findings. A second Monte Carlo study revealed satisfactory finite sample properties of the J Test applied to the neglected nonlinearity, compared with a reference test widely known and used. Overall, the results indicated that the estimation by GMM is a better alternative, especially for data with high noise level.
APA, Harvard, Vancouver, ISO, and other styles
10

Kluskens, Michael S. "Method of moments analysis of scattering by chiral media /." The Ohio State University, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487688507504775.

Full text
APA, Harvard, Vancouver, ISO, and other styles
11

Khlifi, Rachid. "Hybrid space discretizing method -method of moments for numerical modeling of transient interference." kostenfrei, 2007. http://mediatum2.ub.tum.de/doc/620327/document.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
12

Chester, David A. III. "Using the method of moments and Robin Hood method to solve electromagnetic scattering problems." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/78502.

Full text
Abstract:
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2012.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 67-69).
This thesis project was to write a program in C++ that solves electromagnetic scattering problems for arbitrarily shaped scatterers. This was implemented by using a surface integral formulation of Maxwell's equations, which discretizes the surface of the scatterer into thousands of triangles. The method of moments (MoM) was applied, which calculates the Green's functions between each triangle element. A matrix equation is obtained and solved using the Robin Hood (RH) method. The solution to this equation gives the scattered electromangetic field. This program is first tested on a sphere, which is compared to the analytic solution known as Mie scattering. Once these results are confirmed, the program can be used for the KATRIN experiment to ensure that no Penning traps occur in the electron spectrometer.
by David A. Chester.
S.B.
APA, Harvard, Vancouver, ISO, and other styles
13

Liu, Jianguo, and 劉建國. "Fast computation of moments with applications to transforms." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1996. http://hub.hku.hk/bib/B31235086.

Full text
APA, Harvard, Vancouver, ISO, and other styles
14

Liu, Jianguo. "Fast computation of moments with applications to transforms /." Hong Kong : University of Hong Kong, 1996. http://sunzi.lib.hku.hk/hkuto/record.jsp?B17664986.

Full text
APA, Harvard, Vancouver, ISO, and other styles
15

Tham, C. Y. "Electromagnetic transient analysis using the frequency domain method of moments." Thesis, Swansea University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.639176.

Full text
Abstract:
The relative merits of frequency domain (FD) electromagnetic transient analysis against the time domain approach are discussed. When used on highly resonant systems, conventional FD methods which rely on the FFT, can yield erroneous results. This is shown to be due to inadequate sampling resolution, which is determined empirically. The collection of analytical tools for FD analysis is reviewed with emphasis on the control of errors. From these principles a systematic and objective methodology to extract a system's transient response from FD data is proposed. The methodology is extended with a further proposal using dynamic adaptive sampling to obtain an accurate frequency response spectrum efficiently. The proposal is based on the adaptive integration principle but uses a relative convergence limit based on the most recently computed value of integral. The frequency samples obtained are non-uniformly spaced and a modified inverse DFT formula is developed. The sampling strategy results in a very substantial reduction in computational demand over the conventional FFT technique. Accurate transient results can be obtained with typically less than 10% of the samples of the conventional approach. The sampling strategy also enables highly resonant structures to be analysed in the frequency domain. To sample an extremely resonant spectrum accurately, resolution in the order of 1 in 106 is required. This level of computational demand is beyond the practical limit of the conventional FFT methods. The methodology has been used to model transients on resonant wires and transmission lines of various configurations in both antenna and scattering modes. A particular case studied uses an equivalent antenna model of a human body which is standing on a perfect ground and exposed to low frequency radiations. The resulting currents flowing at the feet into the ground, which is adopted as a measure for exposure level, are predicted accurately. The methodology's relative performance in terms of efficiency, accuracy, utility and ease of use against a thin wire time domain integral equation formulation is discussed in some detail.
APA, Harvard, Vancouver, ISO, and other styles
16

Vered, Nissan. "Method of moments analysis of displaced-axis dual reflector antennas." Thesis, Monterey, Calif. : Naval Postgraduate School, 1992. http://handle.dtic.mil/100.2/ADA247970.

Full text
APA, Harvard, Vancouver, ISO, and other styles
17

Zargar, Amin. "Sequence modeling of raft polymerizations with the method of moments." College Park, Md.: University of Maryland, 2008. http://hdl.handle.net/1903/8782.

Full text
Abstract:
Thesis (M.S.) -- University of Maryland, College Park, 2008.
Thesis research directed by: Dept. of Chemical and Biomolecular Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
APA, Harvard, Vancouver, ISO, and other styles
18

SILVA, DENISE FREITAS. "APPLICATION METHOD OF MOMENTS FOR THE ANALYSIS OF CONICAL ANTENNAS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1999. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=7300@1.

Full text
Abstract:
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
Neste estudo faz-se uma análise do desempenho de antenas cônicas compactas para operar em largas bandas de freqüência. Esta análise será feita observando o comportamento da impedância da antena. Serão, primeiramente, consideradas as estruturas convencionais formadas por cones e cones sobrepostos próximos a um plano condutor. Posteriormente, será considerada uma estrutura cônica onde o arredondamento das bordas resulta em um comportamento mais uniforme para a impedância de entrada com variações da freqüência, conferindo um aumento na banda para esta configuração.
The discone antenna is well known as an easy to build multioctave broadband antenna with a omnidirectional radiation pattern in the H-plane, It comprises a plane conductive disc element spaced close to and axially aligned with a conductive cone element. For applications in the UHF and microwave ranges, high performance antennas have been designed to operate from 0.5 to 5 GHz with a VSWR of about 3.5:1 or less. If the length is finite, the impedance still strongly dependent on apex angle as long as the cone is longer than about quarter of wavelength and the apex angle is relatively larger. A problem that is experienced with these antenna designs is the relatively large size required to operate at the low frequencies. In applications where utilization of this antenna. In this work, the analysis and design of these antenna is obtained by employing a rigorous formulation of the electromagnetic scattering problem. As a design tool, we employ Method of Moments for the analysis of rotationally symmetric structures excited by TEM mode. To properly account the variations in driven-point impedance with frequency, the coaxial waveguide used to feed the antenna is also included in the analysis. The excitation is simulated by a distribution of equivalent electric and magnetic currents placed inside the coaxial cable, over a cross-section plane. These currents are defined such that only excite the mode TEM towards the cable-antenna junction. These numerical tool is employed in the shaping the metallic surfaces involved in the discone-type antennas in order to obtain more compact structures. Simple solutions can be easily obtained making the center fed cone and the disc element with radially outer edge portions rolled backwardly and away from each other to form donut-shaped configurations. The ruled edges not only reduce the diameter of the antenna but also permit the current to flow around them smoothly and without reflections that degrade the VSWR at low end of the frequency band.
APA, Harvard, Vancouver, ISO, and other styles
19

Koci, Eni. "The stochastic discount factor and the generalized method of moments." Digital WPI, 2006. https://digitalcommons.wpi.edu/etd-theses/873.

Full text
Abstract:
"The fundamental theorem of asset pricing in finance states that the price of any asset is its expected discounted payoff. Ideally, the payoff is discounted by a factor, which depends on parameters present in the market, and it should be unique, in the sense that financial derivatives should be able to be priced using the same discount factor. In theory, risk neutral valuation implies the existence of a positive random variable, which is called the stochastic discount factor and is used to discount the payoffs of any asset. Apart from asset pricing another use of stochastic discount factor is to evaluate the performance of the of hedge fund managers. Among many methods used to evaluate the stochastic discount factor, generalized method of moments has become very popular. In this paper we will see how generalized method of moments is used to evaluate the stochastic discount factor on linear models and the calculation of stochastic discount factor using generalized method of moments for the popular model in finance CAPM. "
APA, Harvard, Vancouver, ISO, and other styles
20

Masucci, Antonia Maria. "Moments method for random matrices with applications to wireless communication." Thesis, Supélec, 2011. http://www.theses.fr/2011SUPL0011/document.

Full text
Abstract:
Dans cette thèse, on étudie l'application de la méthode des moments pour les télécommunications. On analyse cette méthode et on montre son importance pour l'étude des matrices aléatoires. On utilise le cadre de probabilités libres pour analyser cette méthode. La notion de produit de convolution/déconvolution libre peut être utilisée pour prédire le spectre asymptotique de matrices aléatoires qui sont asymptotiquement libres. On montre que la méthode de moments est un outil puissant même pour calculer les moments/moments asymptotiques de matrices qui n'ont pas la propriété de liberté asymptotique. En particulier, on considère des matrices aléatoires gaussiennes de taille finie et des matrices de Vandermonde al ?eatoires. On développe en série entiére la distribution des valeurs propres de differents modèles, par exemple les distributions de Wishart non-centrale et aussi les distributions de Wishart avec des entrées corrélées de moyenne nulle. Le cadre d'inference pour les matrices des dimensions finies est suffisamment souple pour permettre des combinaisons de matrices aléatoires. Les résultats que nous présentons sont implémentés en code Matlab en générant des sous-ensembles, des permutations et des relations d'équivalence. On applique ce cadre à l'étude des réseaux cognitifs et des réseaux à forte mobilité. On analyse les moments de matrices de Vandermonde aléatoires avec des entrées sur le cercle unitaire. On utilise ces moments et les détecteurs à expansion polynomiale pour décrire des détecteurs à faible complexité du signal transmis par des utilisateurs mobiles à une station de base (ou avec deux stations de base) représentée par des réseaux linéaires uniformes
In this thesis, we focus on the analysis of the moments method, showing its importance in the application of random matrices to wireless communication. This study is conducted in the free probability framework. The concept of free convolution/deconvolution can be used to predict the spectrum of sums or products of random matrices which are asymptotically free. In this framework, we show that the moments method is very appealing and powerful in order to derive the moments/asymptotic moments for cases when the property of asymptotic freeness does not hold. In particular, we focus on Gaussian random matrices with finite dimensions and structured matrices as Vandermonde matrices. We derive the explicit series expansion of the eigenvalue distribution of various models, as noncentral Wishart distributions, as well as correlated zero mean Wishart distributions. We describe an inference framework so flexible that it is possible to apply it for repeated combinations of random ma- trices. The results that we present are implemented generating subsets, permutations, and equivalence relations. We developped a Matlab routine code in order to perform convolution or deconvolution numerically in terms of a set of input moments. We apply this inference framework to the study of cognitive networks, as well as to the study of wireless networks with high mobility. We analyze the asymptotic moments of random Vandermonde matrices with entries on the unit circle. We use them and polynomial expansion detectors in order to design a low complexity linear MMSE decoder to recover the signal transmitted by mobile users to a base station or two base stations, represented by uniform linear arrays
APA, Harvard, Vancouver, ISO, and other styles
21

Killian, Tyler Norton Rao S. M. "Fast solution of large-body problems using domain decomposition and null-field generation in the method of moments." Auburn, Ala, 2009. http://hdl.handle.net/10415/1881.

Full text
APA, Harvard, Vancouver, ISO, and other styles
22

Ordonez, Manuel V. "Method of moments analysis of symmetric dual reflector antennas with feeds." Thesis, Monterey, California. Naval Postgraduate School, 1992. http://hdl.handle.net/10945/23953.

Full text
APA, Harvard, Vancouver, ISO, and other styles
23

Nejmeldeen, Ziad H. (Ziad Hassan) 1976. "General method of moments bias and specification tests for quantile regression." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/17628.

Full text
Abstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Economics, 2003.
Includes bibliographical references (leaves 74-75).
Chapter 1: This chapter looks at a dynamic panel data model with fixed effects. Estimating the model with GMM is consistent but suffers from small sample bias. We apply Helmert's transformation to the model, assume that error terms and nuisance parameters are homoskedastic and independent across observations and of one another, and utilize the GMM bias calculation of Newey & Smith (2001). This leads to a closed form expression for the GMM bias applied to AR(1) model. Chapter 2: This chapter develops specification tests for quantile regression under various data types. We consider what happens to the quantile regression estimator under local and global misspecification and design specification tests that handle a wide range of data types. We consider how to carry out such tests in practice and present Monte Carlo results to show the effectiveness of such tests. Chapter 3: Through a Taylor expansion, We compute the bias of a general GMM model where the weighting matrix A of the moment conditions g(z, β) is left unspecified, except for some general conditions. Our bias results are compared to those of Newey and West (2003). An important case of GMM estimation with a general weighting matrix A is when A is a function of a vector of parameters with fixed dimension. Arellano's IVE estimator is an example of this type of estimator--we consider the bias properties of Arellano's IVE estimator in the AR(1) setting and compare them to our results from Chapter 1.
by Ziad H. Nejmeldeen.
Ph.D.
APA, Harvard, Vancouver, ISO, and other styles
24

Ismatullah. "Analysis of space-borne antennas by higher-order method of moments and inverse equivalent current methods." kostenfrei, 2010. https://mediatum2.ub.tum.de/node?id=977261.

Full text
APA, Harvard, Vancouver, ISO, and other styles
25

Mahachoklertwattana, Pongsak. "A fast full-wave solver for the analysis of large planar finite periodic antenna arrays in grounded multilayered media." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1187152961.

Full text
APA, Harvard, Vancouver, ISO, and other styles
26

Chen, Houfei. "Fast electromagnetic simulation for interconnects on high speed circuits /." Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/5940.

Full text
APA, Harvard, Vancouver, ISO, and other styles
27

Pfeiffer, Robert. "CONSTRAINED DIVERGENCE-CONFORMING BASIS FUNCTIONS FOR METHOD OF MOMENTS DISCRETIZATIONS IN ELECTROMAGNETICS." UKnowledge, 2015. http://uknowledge.uky.edu/ece_etds/79.

Full text
Abstract:
Higher-order basis functions are widely used to model currents and fields in numerical simulations of electromagnetics problems because of the greater accuracy and computational efficiency they can provide. Different problem formulations, such as method of moments (MoM) and the finite element method (FEM) require different constraints on basis functions for optimal performance, such as normal or tangential continuity between cells. In this thesis, a method of automatically generating bases that satisfy the desired basis constraints is applied to a MoM formulation for scattering problems using surface integral equations. Numerical results demonstrate the accuracy of this approach, and show good system matrix conditioning when compared to other higher-order bases.
APA, Harvard, Vancouver, ISO, and other styles
28

McDonald, Paul. "Public bodies, private moments : method acting and American cinema in the 1950s." Thesis, University of Warwick, 1997. http://wrap.warwick.ac.uk/34659/.

Full text
Abstract:
The thesis deals with two central issues: a) the construction of a framework for the study of film acting which places performance in a cultural context b) the cultural significance of Method acting during the 1950s with specific reference to American cinema of the period The first chapter considers the ways in which the voice and body in film acting are made meaningful in the context of beliefs about acting and personal identity. The chapter also proposes ways for situating the practical activity of film acting in a context of cultural production. The remaining chapters study the cultural significance of Method acting through separate analyses of the Method technique, style, representation of gender, and image of star performance. Readings of the Method technique and style are placed in the context of a `culture of personality', in which the significance of the Method was produced in the ways that acting signified beliefs about personal identity. The discussion of the Method style is then developed in the analysis of the ways in which the style was used in film melodramas to represent the gendered anxieties of the rebel hero. Finally, Marlon Brando's image and performances are studied for how the actor personified the meaning of the Method. Together, technique, style, gender representation, and stardom, are studied as various aspects of what is called the Method discourse.
APA, Harvard, Vancouver, ISO, and other styles
29

PRALON, MARIANA GUIMARAES. "APPLICATION OF THE METHOD OF MOMENTS IN THE ANALYSIS OF MICROSTRIP ANTENNAS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2012. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=20556@1.

Full text
Abstract:
PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
INSTITUTO MILITAR DE ENGENHARIA
CENTRO TECNOLÓGICO DO EXÉRCITO
Neste trabalho, o Método dos Momentos é aplicado na análise de antenas microfita excitadas por cabo coaxial, utilizando Funções de Green no modelamento dos campos no interior da camada de dielétrico, o que permite considerar as ondas de superfície excitadas no substrato. Para obter a impedância de entrada da antena microfita, foi implementado um algoritmo numérico para a solução do problema. Neste trabalho, atenção especial é dada à análise de singularidades e ao comportamento assintótico dos integrandos envolvidos na solução numérica do problema. A validação do algoritmo é feita através da comparação com resultados apresentados em referências. Os resultados fornecidos pelo Método dos Momentos são comparados com os obtidos na aplicação de outros métodos na solução do problema. Para esta comparação, são utilizados dois programas comerciais de simulação eletromagnética, o Ansoft HFSS e o CST. São feitas simulações com a variação dos parâmetros de entrada do problema, com o objetivo de assegurar a convergência dos resultados e permitir a comparação com os resultados obtidos pelo Método dos Momentos. São apresentadas diferenças entre os resultados obtidos pelos diversos métodos e analisadas as possíveis causas das discrepâncias.
In the present work, the Method of Moments is applied to the analysis of probe fed antennas. The approach uses Green Functions to model the fields within the dielectric layer, which allows to take into account the surface waves excited in the substrate. A numerical algorithm was implemented in order to obtain the microstrip antenna input impedance. The latter is then verified through the comparison with results presented in references. Special attention is given to the analysis of singularities and to the asymptotic behavior of the integrands involved in the numerical solution. A comparison is drawn between the results obtained with the Method of Moments and those obtained with other methods by employing two electromagnetic simulation commercial softwares, Ansoft HFSS and CST. Simulations with different input parameters are performed in order to ensure convergence of the results and allow comparison with results obtained by the Method of Moments. The differences among the results obtained by the several methods addressed in the analysis are presented and the potential causes of them are analyzed.
APA, Harvard, Vancouver, ISO, and other styles
30

Peters, Matthew E. "Method of moments analysis of artificial media composed of dielectric wire objects." The Ohio State University, 1994. http://rave.ohiolink.edu/etdc/view?acc_num=osu1300290789.

Full text
APA, Harvard, Vancouver, ISO, and other styles
31

Menshikova, M. "Uncertainty estimation using the moments method facilitated by automatic differentiation in Matlab." Thesis, Department of Engineering Systems and Management, 2010. http://hdl.handle.net/1826/4328.

Full text
Abstract:
Computational models have long been used to predict the performance of some baseline design given its design parameters. Given inconsistencies in manufacturing, the manufactured product always deviates from the baseline design. There is currently much interest in both evaluating the effects of variability in design parameters on a design’s performance (uncertainty estimation), and robust optimization of the baseline design such that near optimal performance is obtained despite variability in design parameters. Traditionally, uncertainty analysis is performed by expensive Monte-Carlo methods. This work considers the alternative moments method for uncertainty propagation and its implementation in Matlab. In computational design it is assumed a computational model gives a sufficiently accurate approximation to a design’s performance. As such it can be used for estimating statistical moments (expectation, variance, etc.) of the design due to known statistical variation of the model’s parameters, e.g., by the Monte Carlo approach. In the moments method we further assume the model is sufficiently differentiable that a Taylor series approximation to a model may be constructed, and the moments of the Taylor series may be taken analytically to yield approximations to the model’s moments. In this thesis we generalise techniques considered within the engineering community and design and document associated software to generate arbitrary order Taylor series approximations to arbitrary order statistical moments of computational models implemented in Matlab; Taylor series coefficients are calculated using automatic differentiation. This approach is found to be more efficient than a standard Monte Carlo method for the small-scale model test problems we consider. Previously Christianson and Cox (2005) have indicated that the moments method will be non-convergent in the presence of complex poles of the computational model and suggested a partitioning method to overcome this problem. We implement a version of the partitioning method and demonstrate that it does result in convergence of the moments method. Additionally, we consider, what we term, the branch detection problem in order to ascertain if our Taylor series approximation might only be valid piecewise.
APA, Harvard, Vancouver, ISO, and other styles
32

Obi, Aghogho A. "A Method Of Moments Approach for the Design Of RF Coils for MRI." Digital WPI, 2008. https://digitalcommons.wpi.edu/etd-dissertations/284.

Full text
Abstract:
Magnetic Resonance Imaging (MRI) is a widely used soft-tissue imaging modality that has evolved over the past several years into a powerful and versatile medical diagnostic tool capable of providing in-vivo diagnostic images of human and animal anatomies. Current research efforts in MRI system design are driven by the need to obtain detailed high resolution images with improved image signal-to-noise ratio (SNR) at a given magnetic field strength. Invariably, this requirement demands the development of high performance MRI radio frequency (RF) coils. However, the complexities and stringent requirements of modern clinical MRI systems necessitate the development of new modeling methodologies for the design of high performance RF coils. This dissertation addresses this need by developing a distinct Method of Moments (MoM) modeling approach suitable for the simulation of RF coils loaded with biological tissues. The unique implementation utilizes two distinct basis functions in order to collectively describe the surface current density on the RF coil, and the sum of the volume current density and the displacement current density in the associated biological tissue. By selecting basis functions with similar properties to the actual physical quantities they describe, we avoided spurious solutions normally associated with MoM based implementations. The validity of our modeling method was confirmed by comparisons with analytical solutions as well as physical measurements, yielding good agreement. Furthermore, we applied the MoM based modeling method in the design and development of a novel 4-channel receive-only RF coil for breast imaging in a clinical 1.5T system. The new coil design was inspired by the multi-channel array concept, where multiple conducting strips were arranged in an anatomically conforming profile with the intention of improving sensitivity and SNR. In addition, the coil structure featured an open breast coil concept in order to facilitate MRI-guided biopsy and patient comfort. A comparison of simulation results and actual physical measurements from the prototype RF coil demonstrated good agreement with one another. Also, imaging tests were conducted on a pair of MRI phantoms as well as on a human patient after obtaining proper authorization. The tests revealed good magnetic field homogeneity and a high SNR in the region of interest. In addition, performance comparisons between the prototype 4-channel RF coil and existing high end clinical 4-channel RF breast coils indicated an achievement of superior SNR in conjunction with very good magnetic field homogeneity. Currently, the prototype 4-channel RF coil has outperformed all existing high end clinical 4-channel RF coils used in comparison studies.
APA, Harvard, Vancouver, ISO, and other styles
33

Lemdiasov, Rostislav A. "A general purpose computational approach to the design of gradient coils for arbitrary geometries." Worcester, Mass. : Worcester Polytechnic Institute, 2004. http://www.wpi.edu/Pubs/ETD/Available/etd-09214-155502/.

Full text
APA, Harvard, Vancouver, ISO, and other styles
34

Simmel, Martin. "Numerical solution of the stochastic collection equation: comparison of the linear discrete method and the method of moments." Wissenschaftliche Mitteilungen des Leipziger Instituts für Meteorologie ; 17 = Meteorologische Arbeiten aus Leipzig ; 5 (2000), S. 26-34, 2001. https://ul.qucosa.de/id/qucosa%3A15197.

Full text
Abstract:
The Linear Discrete Method (LDM; SIMMEL 2000; SIMMEL ET AL. 2000) is used to solve the Stochastic Collection Equation (SCE) numerically. Comparisons are made to the Method of Moments (MOM; TzIVION ET AL. 1999) which is suggested as a reference for numerical solutions of the SCE. Simulations for both methods are shown for the GoLOVIN kernel (for which an analytical solution is available) and the hydrodynamic kernel after LONG (1974) as it is used by TZIVION ET AL. (1999). Different bin resolutions are investigated and the simulation times are compared. In addition, LDM simulations using the hydrodynamic kernel after BÖHM (1992b) are presented. The results show that for the GoLOVIN kernel, LDM is slightly closer to the analytic solution than MOM. For the LONG kernel, the low resolution results of LDM and MOM are of similar quality compared to the reference solution. For the BÖHM kernel, only LDM simulations were carried out which show good correspondence between low and high resolution results.
Die lineare diskrete Methode (LDM; SIMMEL 2000; SIMMEL ET AL. 2000) wird dazu benutzt, die Gleichung für stochastisches Einsammeln (stochastic collection equation, SCE) numerisch zu lösen. Dabei werden Vergleiche gezogen zur Methode der Momente (Method of Moments, MOM; TzIVION ET AL. 1999), die als Referenz für numerische Lösungen der SCE vorgeschlagen wurde. Simulationsrechnungen für beide Methoden werden für die Koaleszenzfunktion nach GoLOVIN (für die eine analytische Lösung existiert) und die hydrodynamische Koaleszenzfunktion nach LONG (1974) wie sie von TZIVION ET AL. (1999) verwendet wird, gezeigt. Verschiedene Klassenauflösungen werden untersucht und die Simulationszeiten verglichen. Zusätzlich werden LDM-Simulationen mit der hydrodynamischen Koaleszenzfunktion nach BÖHM (1992b) gezeigt. Die Ergebnisse für die Koaleszenzfunktion nach GoLOVIN zeigen, daß die LDM der analytischen Lösung etwas näher kommt als MOM. Für die Koaleszenzfunktion nach LONG sind die Ergebnisse von LDM und MOM mit niedriger Auflösung von ähnlicher Qualität verglichen mit der Referenzlösung. Für die Koaleszenzfunktion nach BÖHM wurden nur Simulationen mit der LDM durchgeführt, die eine gute Übereinstimmung der Ergebnisse mit niedriger und hoher Auflösung zeigen.
APA, Harvard, Vancouver, ISO, and other styles
35

Ugur, Alper. "Computation of the resonant frequency of a dielectrometer by the method of moments." Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2005. http://wwwlib.umi.com/cr/syr/main.

Full text
APA, Harvard, Vancouver, ISO, and other styles
36

Pant, Mohan Dev. "Simulating Univariate and Multivariate Burr Type III and Type XII Distributions Through the Method of L-Moments." OpenSIUC, 2011. https://opensiuc.lib.siu.edu/dissertations/401.

Full text
Abstract:
The Burr families (Type III and Type XII) of distributions are traditionally used in the context of statistical modeling and for simulating non-normal distributions with moment-based parameters (e.g., Skew and Kurtosis). In educational and psychological studies, the Burr families of distributions can be used to simulate extremely asymmetrical and heavy-tailed non-normal distributions. Conventional moment-based estimators (i.e., the mean, variance, skew, and kurtosis) are traditionally used to characterize the distribution of a random variable or in the context of fitting data. However, conventional moment-based estimators can (a) be substantially biased, (b) have high variance, or (c) be influenced by outliers. In view of these concerns, a characterization of the Burr Type III and Type XII distributions through the method of L-moments is introduced. Specifically, systems of equations are derived for determining the shape parameters associated with user specified L-moment ratios (e.g., L-Skew and L-Kurtosis). A procedure is also developed for the purpose of generating non-normal Burr Type III and Type XII distributions with arbitrary L-correlation matrices. Numerical examples are provided to demonstrate that L-moment based Burr distributions are superior to their conventional moment based counterparts in the context of estimation, distribution fitting, and robustness to outliers. Monte Carlo simulation results are provided to demonstrate that L-moment-based estimators are nearly unbiased, have relatively small variance, and are robust in the presence of outliers for any sample size. Simulation results are also provided to show that the methodology used for generating correlated non-normal Burr Type III and Type XII distributions is valid and efficient. Specifically, Monte Carlo simulation results are provided to show that the empirical values of L-correlations among simulated Burr Type III (and Type XII) distributions are in close agreement with the specified L-correlation matrices.
APA, Harvard, Vancouver, ISO, and other styles
37

Zhuang, Wei. "A 3-d capacitance extraction algorithm based on kernel independent hierarchical method and geometric moments." Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969.1/5794.

Full text
Abstract:
A three dimensional (3-D) capacitance extraction algorithm based on a kernel independent hierarchical method and geometric moments is described. Several techniques are incorporated, which leads to a better overall performance for arbitrary interconnect systems. First, the new algorithm hierarchically partitions the bounding box of all interconnect panels to build the partition tree. Then it uses simple shapes to match the low order moments of the geometry of each box in the partition tree. Finally, with the help of a fast matrix-vector product, GMRES is used to solve the linear system. Experimental results show that our algorithm reduces the linear system's size greatly and at the same time maintains a satisfying accuracy. Compared with FastCap, the running time of the new algorithm can be reduced more than a magnitude and the memory usage can be reduced more than thirty times.
APA, Harvard, Vancouver, ISO, and other styles
38

Imeci, Sehabeddin Taha. "Transmission through an arbitrarily shaped aperture in a conducting plane separating air and a chiral medium." Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available, full text:, 2007. http://wwwlib.umi.com/cr/syr/main.

Full text
APA, Harvard, Vancouver, ISO, and other styles
39

Caswell, Eric D. "Analysis of a Helix Antenna Using a Moment Method Approach With Curved Basis and Testing Functions." Thesis, Virginia Tech, 1998. http://hdl.handle.net/10919/37001.

Full text
Abstract:
Typically wire antenna structures are modeled by approximating curved structures with straight wire segments. The straight wire approximation yields accurate results, but often requires a large number of segments to adequately approximate the antenna geometry. The large number of straight wire segments or unknowns requires a large amount of memory and time to solve for the currents on the antenna. By using curved segments which exactly describe the contour of the antenna geometry the number of unknowns can be reduced, thus allowing for bigger problems to be solved accurately. This thesis focuses on the analysis of a helix antenna. The Method of Moments is used to solve for the currents on the antenna, and both the triangle basis and pulse testing functions exactly follow the contour of the helix antenna. The thin wire approximation is used throughout the analysis. The helix is assumed to be oriented along the z-axis with an optional perfect electric conductor (PEC) ground plane in the x-y plane. For simplicity, a delta gap source model is used. Straight feed wires may also be added to the helix, and are modeled similarly to the helix by the Method of Moments with triangular basis and pulse testing functions. The primary validation of the curved wire approach is through a comparison with MININEC and NEC of the convergence properties of the input impedance of the antenna versus the number of unknowns. The convergence tests show that significantly fewer unknowns are needed to accurately predict the input impedance of the helix, particularly for the normal mode helix. This approach is also useful in the analysis of the axial mode helix where the current changes significantly around one turn. Because of the varying current distribution, the improvement of impedance convergence with curved segments is not as significant for the axial mode helix. However, radiation pattern convergence improvement is found. Multiple feed structures for the axial mode helix are also investigated. In general, the many straight wire segments, and thus unknowns, that are needed to accurately approximate the current around one turn can be greatly reduced by the using the curved segment method.
Master of Science
APA, Harvard, Vancouver, ISO, and other styles
40

Seo, Seung Mo. "A fast IE-FFT algorighm for solving electromagnetic radiation and scattering problems." The Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=osu1149105460.

Full text
APA, Harvard, Vancouver, ISO, and other styles
41

Kent, William J. "Plane wave scattering by thin linear dielectric-coated wires and dielectric strips : a moment method approach with physical basis functions /." The Ohio State University, 1985. http://rave.ohiolink.edu/etdc/view?acc_num=osu148726053195675.

Full text
APA, Harvard, Vancouver, ISO, and other styles
42

Kulkarni, Shashank D. "Development and validation of a Method of Moments approach for modeling planar antenna structures." Worcester, Mass. : Worcester Polytechnic Institute, 2007. http://www.wpi.edu/Pubs/ETD/Available/etd-042007-151741/.

Full text
Abstract:
Dissertation (Ph.D.)--Worcester Polytechnic Institute.
Keywords: patch antennas; volume integral equation (VIE); method of moments (MoM); low order basis functions; convergence. Includes bibliographical references (leaves 169-186 ).
APA, Harvard, Vancouver, ISO, and other styles
43

Laskay, Ünige A. "Dynamic collision induced dissociation : a novel fragmentation method in the quadrupole ion trap /." View abstract, 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3353544.

Full text
APA, Harvard, Vancouver, ISO, and other styles
44

Gamage, Jagath Kumara Halpe. "Efficient Space Domaine Method of Moments for Large Arbitrary Scatterers in Planar Stratified Media." Doctoral thesis, Norwegian University of Science and Technology, Department of Electronics and Telecommunications, 2004. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-398.

Full text
Abstract:

Keywords : Conjugate gradient fast Fourier transform (CG-FFT), Discrete complex image method (DCIM), Electric field integral equation (EFIE), Frequency selective surfaces (FSS), Generalized pencil-of-functions (GPOF), Green’s function (GF), Method of moments (MoM), Prony’s method (PM), Sommerfeld integral (SI), Two-dimensional generalized exponential integral (2D-GEI)

As the need for more frequency spectrum drives the design of antennas and other microwave components at higher frequencies, compact but electrically large microwave components are beginning to appear. Since a significant share of these components comprises scatterers etched on planar stratified layers, efficient tools analyzing and optimizing such structures are invaluable. The work carried out here is in fact a continuation of the research performed in the past at the Department of Electronics and Telecommunications at the Norwegian University of Science and Technology in Trondheim, Norway.

The conventional method of moments for analyzing and optimizing scatterers in stratified media is simple in formulation but computationally very intensive. Moreover, the computer memory usage of the software based on conventional MoM is high. Both these factors have so far limited the application of conventional MoM to electrically small and simpler stratified structures. Therefore, the present work focuses on introducing and implementing an improved space domain MoM for large radiating or scattering structures etched on planar stratified media. The space domain method of moments is selected due to its simplicity and potential for further improvements when compared with the spectral domain method of moments.

The major areas of space domain MoM such as finding spectral Green's functions, deriving spatial Green’s functions, matrix formulation and matrix inversion are addressed.

The existing methods are evaluated with respect to their pros and cons. In addition, in order to extract the scattering parameters a few simple de-embedding techniques are introduced. We have attempted to optimize each stage of the conventional space domain MoM such that it can handle electrically large scatterers in planar stratified media. Each method is discussed independently and proved to be performing well compared with the corresponding method applied in conventional space domain MoM. In deriving spectral Green’s functions, a novel formulation of transmission line theory is applied easing the analytical derivation and the software implementation significantly. A robust form of discrete complex image method (DCIM) is used in deriving spatial Green’s functions from the corresponding spectral Green’s functions. DCIM is an accurate and efficient way of evaluating Sommerfeld integrals without resorting to multi-dimensional numerical integration.

The accuracy and efficiency of DCIM are affirmed by applying it to simple scatterers. The outcome of DCIM is a sum of complex exponential functions. These are then used to calculate the impedance matrices of MoM. It is also shown that when using mixed potential integral formulation, the original four-dimensional numerical integration can be simplified to two-dimensional integration with no loss of accuracy, thus reducing the mathematical complexity during matrix filling phase. Nevertheless, some of the complex exponential functions can lead to two-dimensional singular integrals. These singular two- dimensional generalized exponential integrals(2D-GEI) are efficiently handled by generalizing an innovative numerical integration method, thus saving the processing time further. The last but most important operation of MoM, the matrix inversion is achieved by using an iterative algorithm known as conjugate gradient method. It is then combined with fast Fourier transform to exploit the space invariant property present in the impedance matrices of MoM. A new compact formulation of the matrices is also presented to facilitate the programing task. To our knowledge, this is the first time such formulation is presented explicitly. A brief chapter is reserved for de-embedding of scattering parameters from the surface current densities resulting from MoM.

In order to present the thesis as a collection of self-containing and independent chapters, results are included in each chapter whenever it is appropriate. These partial results confirm the accuracy and the efficiency of each method introduced in the corresponding chapter before we move on to the next. The conclusion on the overall method introduced in this work is that the space domain method of moments combined with the discrete complex image method and the conjugate gradient fast Fourier transform presents a very powerful tool for analyzing and optimizing large arbitrary stratified structures. However, to be competitive with commercial products based on either spectral domain method of moments or finite element methods, further improvements in its implementation and methodology are needed. Few improvements such as more efficient implementation of the entire method, inclusion of surface wave contribution in DCIM, integration of non-uniform basis and testing functions and need for better de-embedding techniques are already identified at the end of this work.

Finally we hope that this work clarifies some important issues relating to space domain method of moments when applied to large scatterers etched on planar stratified media and encourages the further research on this particular method.

APA, Harvard, Vancouver, ISO, and other styles
45

Silvestri, Francesco [Verfasser], and Gerhard [Akademischer Betreuer] Reinelt. "Representations of Partition Problems and the Method of Moments / Francesco Silvestri ; Betreuer: Gerhard Reinelt." Heidelberg : Universitätsbibliothek Heidelberg, 2017. http://d-nb.info/1177688638/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
46

Kwon, Do-Hoon. "Efficient method of moments formulation for large conducting scattering problems using asymptotic phasefront extraction /." The Ohio State University, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=osu1488195633519868.

Full text
APA, Harvard, Vancouver, ISO, and other styles
47

Edlund, Johan. "A parallel, iterative method of moments and physical optics hybrid solver for arbitrary surfaces." Licentiate thesis, Uppsala universitet, Avdelningen för teknisk databehandling, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-86001.

Full text
Abstract:
We have developed an MM–PO hybrid solver designed to deliver reasonable accuracy inexpensively in terms of both CPU-time and memory demands. The solver is based on an iterative block Gauss–Seidel process to avoid unnecessary storage and matrix computations, and can be used to solve the radiation and scattering problems for both disjunct and connected regions. It supports thin wires and dielectrica in the MM domain and has been implemented both as a serial and parallel solver. Numerical experiments have been performed on simple objects to demonstrate certain keyfeatures of the solver, and validate the positive and negative aspects of the MM/PO hybrid. Experiments have also been conducted on more complex objects such as a model aircraft, to demonstrate that the good results from the simpler objects are transferrable to the real life situation. The complex geometries have been used to conduct tests to investigate how well parallelised the code is, and the results are satisfactory.
APA, Harvard, Vancouver, ISO, and other styles
48

Horiki, Yasutaka. "A self calibration technique for a DOA array in the presence of mutual coupling and resonant scatterers." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1158610758.

Full text
APA, Harvard, Vancouver, ISO, and other styles
49

Courthial, Lucile, Arnaud Baudot, Elsa Jolimaitre, Melaz Tayakout, and Christian Jallut. "Moments method applied to the In-Situ characterisation of normal butane mass transfer in MFI zeolite membranes: Moments method applied to the In-Situ characterisation of normalbutane mass transfer in MFI zeolite membranes." Diffusion fundamentals 2 (2005) 88, S. 1-2, 2005. https://ul.qucosa.de/id/qucosa%3A13373.

Full text
APA, Harvard, Vancouver, ISO, and other styles
50

Dřímal, Marek. "How Does the New Keynesian Phillips Curve Forecast the Rate of Inflation in the Czech Economy?" Master's thesis, Vysoká škola ekonomická v Praze, 2011. http://www.nusl.cz/ntk/nusl-198859.

Full text
Abstract:
This analysis studies the phenomenon of the New Keynesian Phillips Curve - its inception from the RBC theory and DSGE modelling via incorporation of nominal rigidities, and its various specifications and empirical issues. The estimates on Czech macroeconomic data using the Generalised Method of Moments show that the hybrid New Keynesian Phillips Curve with the labour income share or the real unit labour cost as driving variables can be considered as an appropriate model describing inflation in the Czech Republic. Compared to other analyses, we show that the inflation process in the Czech Republic exhibits higher backwardness vis-a-vis other researchers' estimates based on US data.
APA, Harvard, Vancouver, ISO, and other styles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography