Modelling and optimization of a permanent-magnet machine in a flywheel

This thesis describes the derivation of an analytical model for the design and optimization of a permanent-magnet machine for use in an energy storage flywheel. A prototype of this flywheel is to be used as the peak-power unit in a hybrid electric city bus. The thesis starts by showing the feasibility of using a flywheel energy storage system...

Automatic Lipreading in the Dutch Language

This thesis deals with many aspects of the bimodal speech processing research. It lays out the general framework of visually enhanced speech processing computer systems together with some insight in the human speech bimodal speech perception. There are three main contributions to the field of bimodal speech processing presented in the thesis....

Electrodynamics in deformable solids for electromagnetic forming

The behaviour of matter in an electromagnetic field may be considered as a very complex problem, involving not only electromagnetism but also mechanics and thermodynamics. The interaction field-matter is not simple even for a rigid body, and it becomes more complicated for a deforming body, as long as all the physical quantities that...

A mathematical analysis of a belt system with a low and time-varying velocity

In this thesis a mathematical analysis has been given for model which describes the transversal vibrations of belt systems. The belt speed is assumed to be time-varying and to be small compared to the wave speed. Not only linear string-like or beam-like models but also nonlinear models have been studied. In all cases initial-boundary value...

On asymptotic approximations of first integrals for a class of nonlinear oscillators

In this thesis a class of nonlinear oscillator equations is studied. Asymptotic approximations of first integrals for the nonlinear differential equations are constructed by using the recently developed perturbation method based on integrating vectors. The existence and the stability of time-periodic solutions can be determined from these...

Design of Nonlinear Circuits: The Linear Time-Varying Approach

Over the last years the ever-growing demand for higher performance has led to much interest in using nonlinear circuit concepts for electronic circuit design. For this we have to deal with analysis and synthesis of dynamic nonlinear circuits. This thesis proposes to handle the nonlinear design complexity by dividing the design process in two...

On the behaviour of classes of min-max-plus systems

Discrete Event Systems are systems, the time evolution of which can be described by the occurence of events. Well-known examples of DESs are manufacturing systems and transportation networks. An important class of DESs can be described by the so-called (max,+) algebra, in which, compared to the usual arithmetic, the operator + is replaced by the...

Train-induced ground vibrations: Modeling and experiments

Ground vibrations generated by high-speed trains are of great concern because of the possible damage they can cause to buildings or other structures near the track, and the annoyance to the public living in the vicinity of the track. Particularly in soft-soil regions, where the wave speed is comparable to the speed of the trains, a strong...

An analytic semigroup approach to convolution Volterra equations

Ergodic Properties of Continued Fraction Algorithms

Renewal Processes and Repairable Systems

In this thesis we discuss the following topics: 1. Renewal reward processes The marginal distributions of renewal reward processes and its version, which we call in this thesis instantaneous reward processes, are derived. Our approach is based on the theory of point processes, especially Poisson point processes. The idea is to represent the...

CMOS-based Integrated Wavefront Sensor

This thesis addresses the design, implementation and performance of an integrated Hartmann-Shack wavefront sensor suitable for real-time operation and compatible with a standard technology. A wavefront sensor can be used for the detection of distortions in the profile of a light beam or of an optical component.With such a sensor, one can, for...

Improving ICT Management in Public Universities in Kenya

With the rapid infusion of information and communication technology (ICT) in Kenya in the recent past, organizations are now realizing the critical role that management, control and maintenance of ICT play in providing and improving ICT services to the user communities. Public universities as agents of technological transfer in the developing...

Full-Wave Analysis of Electrically Large Reflector Antennas

In this thesis, a full-wave analysis of electrically large reflector antennas (with a surface in the order of several thousands of square wavelengths) is presented. The mathematical model used for the analysis is the Electric Field Integral Equation (EFIE), applied to infinitely thin, Perfectly Conducting (PEC) surfaces. The Method of Moments ...

Data assimilation in atmospheric chemistry models using Kalman filtering

The problem of air pollution around urbanized area across Europe is strongly related to ozone. Ozone is a result of photo-chemical oxidation, and therefore an indication of the presence of pollutants. Overexposure to ozone is harmful to the health, and the concentrations are therefore measured on a regular basis to check exceedance of air...

A Seismic Transmission System for Continuous Monitoring of the Lithosphere: A Proposition

The main objective of this thesis is to enhance earthquake prediction feasibility. We present the concept and the design layout of a novel seismic transmission system capable of continuously monitoring the Lithosphere for changes in Earth physics parameters governing seismic wave propagation. New-technology seismic vibrator sources (magnetic...