• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 412
  • 128
  • 102
  • 54
  • 11
  • 8
  • 7
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 2
  • Tagged with
  • 865
  • 169
  • 167
  • 142
  • 117
  • 108
  • 101
  • 89
  • 87
  • 85
  • 78
  • 76
  • 74
  • 72
  • 71
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Test of independence of subvectors in multivariate analysis

Khan, Nazeer. January 1984 (has links)
No description available.
82

Asymptotic Formulas For Large Arguments Of Hypergeometric-type Functio

Heck, Adam 01 January 2004 (has links)
Hypergeometric type functions have a long list of applications in the field of sciences. A brief history is given of Hypergeometric functions including some of their applications. A development of a new method for finding asymptotic formulas for large arguments is given. This new method is applied to Bessel functions. Results are compared with previously known methods.
83

Approximation by Bernstein polynomials at the point of discontinuity

Liang, Jie Ling 01 December 2011 (has links)
Chlodovsky showed that if x0 is a point of discontinuity of the first kind of the function f, then the Bernstein polynomials Bn(f, x0) converge to the average of the one-sided limits on the right and on the left of the function f at the point x0. In 2009, Telyakovskii in (5) extended the asymptotic formulas for the deviations of the Bernstein polynomials from the differentiable functions at the first-kind discontinuity points of the highest derivatives of even order and demonstrated the same result fails for the odd order case. Then in 2010, Tonkov in (6) found the right formulation and proved the result that was missing in the odd-order case. It turned out that the limit in the odd order case is related to the jump of the highest derivative. The proofs in these two cases look similar but have many subtle differences, so it is desirable to find out if there is a unifying principle for treating both cases. In this thesis, we obtain a unified formulation and proof for the asymptotic results of both Telyakovskii and Tonkov and discuss extension of these results in the case where the highest derivative of the function is only assumed to be bounded at the point under study.
84

Asymptotic expansion for the <i>L</i><sup>1</sup> Norm of N-Fold convolutions

Stey, George C. 27 March 2007 (has links)
No description available.
85

Identificação de sistemas através do método assintótico. / System identification through the asymptotic method.

Misoczki, Rodolfo 04 October 2011 (has links)
A Identificação de Sistemas é uma das técnicas utilizadas para se obter a representação matemática de um sistema. Diversos métodos podem ser aplicados para se obter um modelo matemático através da identificação de sistemas, entre eles o método de identificação assintótico, também chamado de ASYM (Zhu, 1998). Este trabalho propõe aplicar o método de identificação assintótico em sistemas SISO para a obtenção de modelo de sistemas ditos caixa-preta e avaliar o seu desempenho buscando também o melhor detalhamento do método. Os modelos obtidos foram avaliados de acordo com sua nota calculada através do método ASYM, através da comparação do índice de ajuste fit para autovalidação e validação cruzada e pela variância dos parâmetros dos modelos. O método ASYM é exaustivamente testado para sua avaliação. Entre os testes realizados neste trabalho destacam-se dois experimentos tipo Monte-Carlo com mais de quinhentas identificações e a aplicação do método em uma planta real. Os testes comprovaram a viabilidade da aplicação do método assintótico na identificação de sistemas SISO do tipo caixa-preta com excelente desempenho para estruturas ARMAX. / System Identification is one of the techniques used to obtain the mathematical representation of a system. Several methods can be applied to obtain a mathematical model by the system identification, including the asymptotic method, also called ASYM (Zhu, 1998). This work proposes to apply the ASYM method for SISO systems identification, then obtain models of black-box systems called \"black box\" and evaluate its performance and show details of the method. The models obtained were evaluated according to their grade calculated using the ASYM method, by comparing the fit adjustment index, self-validation and cross validation and the variance of model parameters. The asymptotic method has been extensively tested to be evaluated. Among the tests in this work, two stand out such Monte Carlo experiments with more than five hundred identifications and a real plant identification. The tests proved the feasibility of applying the asymptotic method in the \"black box\" SISO systems identification with excellent performance for ARMAX structures.
86

Spike-vortex solutions for nonlinear Schrödinger system.

January 2007 (has links)
Wang, Yuqian. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 36-39). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgement --- p.ii / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Properties of approximate solutions --- p.6 / Chapter 3 --- Liapunov-Schmidt Reduction --- p.17 / Chapter 4 --- Critical point of the reduced energy functional --- p.28 / Bibliography --- p.36
87

Estimating the inevitability of fast oscillations in model systems with two timescales

Choy, Vivian K.Y, 1971- January 2001 (has links)
Abstract not available
88

Asymptotic behavior of a certain third order differential equation

Al-Ahmar, Mohamed 03 June 2011 (has links)
In order to introduce the investigation contemplated in this thesis, let us consider the differential equation d3y d2y dyz3 ____+ z2___(b0 + blzm) + z - (c0 + clzm) dz3 dz2 dz+ (d0 + dlzm + d2z2m) y = 0Here, m is an arbitrary positive integer and the variable z is complex as are the constantsbi,ci (i=0,1) and di (i=0,1,2) with d2≠0. It is also assumed that the difference of no two roots of the indicial equation about z = 0 is congruent to zero modulo m.Ball State UniversityMuncie, IN 47306
89

Qualitative Behavior Of Solutions Of Dynamic Equations On Time Scales

Mert, Raziye 01 January 2010 (has links) (PDF)
In this thesis, the asymptotic behavior and oscillation of solutions of dynamic equations on time scales are studied. In the first part of the thesis, asymptotic equivalence and asymptotic equilibrium of dynamic systems are investigated. Sufficient conditions are established for the asymptotic equivalence of linear systems and linear and quasilinear systems, respectively, and for the asymptotic equilibrium of quasilinear systems by unifying and extending some known results for differential systems and difference systems to dynamic systems on arbitrary time scales. In particular, for the asymptotic equivalence of differential systems, the well-known theorems of Levinson and Yakubovich are improved and the well-known theorem of Wintner for the asymptotic equilibrium of linear differential systems is generalized to arbitrary time scales. Some of our results for asymptotic equilibrium are new even for difference systems. In the second part, the oscillation of solutions of a particular class of second order nonlinear delay dynamic equations and, more generally, two-dimensional nonlinear dynamic systems, including delay-dynamic systems, are discussed. Necessary and sufficient conditions are derived for the oscillation of solutions of nonlinear delay dynamic equations by extending some continuous results. Specifically, the classical theorems of Atkinson and Belohorec are generalized. Sufficient conditions are established for the oscillation of solutions of nonlinear dynamic systems by unifying and extending the corresponding continuous and discrete results. Particularly, the oscillation criteria of Atkinson, Belohorec, Waltman, and Hooker and Patula are generalized.
90

Asymptotic properties of Müntz orthogonal polynomials

Stefánsson, Úlfar F. 12 May 2010 (has links)
Müntz polynomials arise from consideration of Müntz's Theorem, which is a beautiful generalization of Weierstrass's Theorem. We prove a new surprisingly simple representation for the Müntz orthogonal polynomials on the interval of orthogonality, and in particular obtain new formulas for some of the classical orthogonal polynomials (e.g. Legendre, Jacobi, Laguerre). This allows us to determine the strong asymptotics and endpoint limit asymptotics on the interval. The zero spacing behavior follows, as well as estimates for the smallest and largest zeros. This is the first time that such asymptotics have been obtained for general Müntz exponents. We also look at the asymptotic behavior outside the interval and the asymptotic properties of the associated Christoffel functions.

Page generated in 0.0367 seconds