Geometric frustration occurs when local order cannot propagate through space. A common example is the surface of a soccer ball, which cannot be tiled with hexaganons only. Geometric frustration can... Show moreGeometric frustration occurs when local order cannot propagate through space. A common example is the surface of a soccer ball, which cannot be tiled with hexaganons only. Geometric frustration can also be present in materials. In fact, geometry can act as an instrument to design the mechanical, optical or physical properties of fluids and solids. The first two parts of this thesis discuss frustrated liquid crystals confined to droplets of various shapes and sizes. The droplet shape determines the orientation of the liquid crystal molecules and in turn its response to light. In the final part we study the fracture mechanics of curved elastic plates. By tuning the curvature of the plate, the critical length at which the crack starts growing can be controlled. Finally, we find that the path that the crack takes depends on the curvature. Show less
As the de facto industry standard for software modeling, the Unified Modeling Language (UML) is used widely across various IT domains. UML__s wide acceptance is partly because the language offers... Show moreAs the de facto industry standard for software modeling, the Unified Modeling Language (UML) is used widely across various IT domains. UML__s wide acceptance is partly because the language offers flexibility and freedom in modeling software systems: 1) UML provides an extensive set of modeling notations that can be used to model various concepts; 2) UML can be used both in a casual and formal manners. In the context of model-driven software development, the degree of freedom in which UML is used raises an important issue related to model quality. Different styles and rigors in using UML affect the quality of the resulting models. It is then logical to think that the level of quality of the UML model may affect the quality of the resulting software. This thesis reports on a series of empirical studies performed to address a pivotal question concerning the benefits of UML modeling in software development, particularly from a quality perspective. The results of these empirical studies show that the use of UML provides benefits in terms of increased quality and productivity in software development. The availability of UML models also allows early prediction of defects in software systems. Such prediction is potentially useful for identifying and fixing defects early during software development, and for prioritizing testing. Show less
