I'm just back from lovely Zurich having examined Susanna Cech Previtali's PhD entitled "Dynamic updating of object-oriented software systems based on aspects". The key idea in the thesis is that an upgrade is a cross-cutting concern. Susanna has built a tool that takes two builds of an application and, if possible, produces an aspect that captures the change from the old version to the new version. The old version can then be dynamically updated by weaving in the aspect. Susanna has (impressively) built this system, using the PROSE dynamic aspect system. She has also undertaken a systematic empirical study using many builds of eight popular open-source Java applications.
Her thesis work is very impressive, so it wasn't a particularly hard decision for the thesis committee:-) She'll be working on a final version of the dissertation over the next few months, so I'll post a link when it's available.
Well done, Susanna!