The purpose of this work was to study the rectangular dielectric waveguide and its transitions to metalwaveguide at millimeter wavelengths. The thesis reviews different dielectric waveguiding structures, theiranalysis methods and their transitions to the metal waveguide. In this thesis work the analysis methods andtransitions are further developed. The main results of this work are:...

Interpolation of a spatially correlated random process is used in many areas. The best unbiased linear predictor, often called kriging predictor in geostatistical science, requires the solution of a large linear system based on the covariance matrix of the observations. In this article, we show that tapering the correct covariance matrix with an appropriate compactly supported covariance functi...

The dynamic problems of a microactuator with a single edge crack are numerically formulated using radial basis functions. The microactuator model incorporates the taper ratio, electrode shapes, and crack length, all of which govern the dynamic behavior of microactuators. To optimize the design of a microactuator, many characteristics of various shaped cantilevers and curved electrodes are also ...

When the spatial sample size is extremely large, which occurs in many environmental and ecological studies, operations on the large covariance matrix are a numerical challenge. Covariance tapering is a technique to alleviate the numerical challenges. Under the assumption that data are collected along a line in a bounded region, we investigate how the tapering affects the asymptotic efficiency o...

Bandable covariance matrices are often used to model the dependence structure of variables that follow a nature order. It has been shown that the tapering covariance estimator attains the optimal minimax rates of convergence for estimating large bandable covariance matrices. The estimation risk critically depends on the choice of the tapering parameter.We develop a Stein’s Unbiased Risk Estimat...

Parameter estimation for and prediction of spatially or spatio–temporally correlated random processes are used in many areas and often require the solution of a large linear system based on the covariance matrix of the observations. In recent years, the dataset sizes to which these methods are applied have steadily increased such that straightforward statistical tools are computationally too ex...

The Earth will require sustainable electricity sources equivalent to 3 to 5 times the commercial power presently produced by 2050. Solar Power Satellite (SPS) is one option for meeting the huge future energy demand. SPS can send enormous amounts of power to the Earth as the form of microwave (MW). A highly efficient microwave power transmission (MPT) system is needed for SPS. A critical goal of...

BACKGROUND Long-term use of hypnotics is not recommended because of risks of dependency and adverse effects on health. The usual clinical management of benzodiazepine dependency is gradual tapering, but when used alone this method is not highly effective in achieving long-term discontinuation. We compared the efficacy of tapering plus cognitive-behavioural therapy for insomnia with tapering alo...

Some patients with severe asthma are difficult to control and suffer from frequent exacerbations, whereas others remain stable with anti-inflammatory therapy. To investigate mechanisms of exacerbations, we compared 13 patients 20 to 51 yr of age (11 female, two male) with difficult-to-control asthma (two or more exacerbations during the previous year) and 15 patients 20 to 47 yr of age (13 fema...