Browsing by Subject "Asymptotic expansion"

Now showing 1 - 2 of 2

Open Access
Asymptotic expansions for test statistics and tests for normality based on robust regression
(1999) Önder, A. Özlem
This dissertation focuses on two different topics in econometrics. The first one is presented in Chapter 2 and is related to higher order asymptotic theory. The power of the Lagrange multiplier, Wald and likelihood ratio tests for the first order autoregressive model is compared through the approximations to the distributions of these three tests. The adequacy of the approximation is examined. The Wald and likelihood ratio tests are found to have superior performance than the Lagrange multiplier test. The comparisons are done according to stringency of the test statistics. As a second topic in Chapter 3, the dissertation examines the use of residuals from robust regression instead of OLS residuals in test statistics for the normality of the errors. According to simulation results their improvement over standard normality tests is found only in specialized circumstances. The applications on real data set show these conditions occur often enough in practice.
Open Access
Last PhD supervised by Professor Kouyoumjian: Extended UTD by Dr. Buyukdura
(IEEE, 2011) Altıntaş, Ayhan
While he is a Professor Emeritus at Ohio State, Professor Kouyoumjian supervised a thesis work by Merih Buyukdura. They first derived a dyadic Green's function for a PEC wedge using spherical wave functions and employed asymptotic approximation. They also derived the extended UTD in which higher order terms in the diffraction matrix are predicted. The thesis was defended in 1984. In this presentation, a brief discussion of edge waves as derived from the asymptotic expansion of dyadic Green's function in terms of spherical functions will be made and afterwards the derivation of extended UTD diffraction coefficients will be given. © 2011 IEEE.