Browsing by Subject "Engineering mathematics"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
Item Fast real-time monitoring of rotating machines(Texas Tech University, 2003-08) McHale, Gary BrentThis project involves the application of methods and techniques that have been developed for high performance control of relatively slow turning industrial machines and extends these techniques to the more demanding regime of AC-machines used for kinetic energy storage and fast AC-servos for military applications. In particular, techniques for fast monitoring of the output voltage of AC-generators will be discussed. To accomplish fast monitoring, the (sinusoidal) AC output voltage is converted to a DC quantity that represents the instantaneous amplitude. This is achieved through the use of a rotational transformation. This transformation, also called 'Vector Rotation," can be used for very fast observation of the momentary amplitudes of electrical machine quantities. The hardware that was designed to control the machines will also be discussed in extreme detail. The procedure is implemented by tightly integrating a digital motion control co-processor into the memory map of a 16-bit microcontroller.Item Three-dimensional mortar finite element method for convection-diffusion equation with nonconforming meshes(Texas Tech University, 2003-08) McGee, Wayne MichaelIn the last decade, non-conforming domain decomposition methods such as the mortar finite element method have been shown to be reliable techniques for several engineering applications that often employ complex finite element design. With this technique, one can conveniently assemble local subcomponents into a global domain without matching the finite element nodes of each subcomponent at the common interface. We employ the mortar finite element formulation in conjunction with higher-order elements, where both mesh refinement and degree enhancement are combined to increase accuracy. The mortar finite element method has proven to be a good candidate for implementation in two dimensions. In this work, for the first time, we present computational results for the convergence of the mortar finite element technique in three dimensions for the convection-diffusion equation. Our numerical results demonstrate optimality for the resulting non-conforming method for various mesh and polynomial degree discretizations.Item Time series analysis of ECG data and unreliable forecasting(Texas Tech University, 1997-12) Gupta, DipankarIt is of great interest to the medical community if we can predict the fatality of cardiac arrest so that they can provide effective treatment by observing individual Electrocardiograph (ECG) time series data. We usually use linear models because they are simple and easy to apply. But linear systems that are used to describe complex biological system such as ECG data are no longer satisfactory. For the ECG data , it is expected that a non linear system will provide more complete and parsimonious description of the dynamics as well as it will give additional insight into the underlying physiology. But many authors have found that some proposed classical statistical non linear models are totally imable to forecast with reasonable accuracy and that the forecast is even worse than linear prediction. The question naturally arises whether the ECG data at all represent some well known statistical non linear system. In this thesis , we want to understand this problem. For this purpose , we study different sispects of ECG data, which includes understanding the ECG system and ascertaining what specific assumptions could be justified given the nature of the data. This type of problem is widespread in statistics and we shed some more light in this matter from our study.