Discontinuous Galerkin Methods for Friedrichs Systems with Irregular Solutions Max Jensen Doctor of Philosophy Corpus Christi College Michaelmas Term 2004 This work is concerned with the numerical solution of Friedrichs systems by discontinuous Galerkin finite element methods (DGFEMs). Friedrichs systems are boundary value problems with symmetric, positive, linear first-order partial differenti...

The results of numerical and experimental investigation of trapezoidal cantilevers with irregular cross-sections are presented in this paper. Modifications of the cross-section were made in order to increase strain and improve its distribution in the piezo ceramic layer of a cantilever. The proposed modifications allowed improving the energy conversion coefficient and increasing the power densi...

The present study examined the occurrence of sleepiness in various shift combinations ending with a night or morning shift. Three weeks' sleep/work shift diary data, collected from 126 randomly selected train drivers and 104 traffic controllers, were used in statistical analyses. The occurrence of sleepiness at work (i.e., Karolinska Sleepiness Scale 7 or higher) was tested with a generalised l...

We report a new type of Hamiltonian equations and maximum principle for the optimal control of a Goursat system when the underlying domain of 2-D "time" is not rectangular and has non-smooth boundary. The resulting Hamiltonian equations form a system of impulsive hyperbolic partial differential equations, with the impulses induced by the conditions on the costate at points of discontinuity on t...

In this work we present the results of a numerical and semiclassical analysis of high lying states in a Hamiltonian system, whose classical mechanics is of a generic, mixed type, where the energy surface is split into regions of regular and chaotic motion. As predicted by the principle of uniform semiclassical condensation (PUSC), when the effective h̄ tends to 0, each state can be classified as...

Most standard tomographic inversion methods require many measurements with a regular coverage of the object studied. A new method has been developed to obtain tomographic reconstructions from measurements by systems with a small number of detectors and an irregular coverage. The method reconstructs values on a regular grid in projection space from the measurements on an irregular grid by an ite...