VanHilst, Michael

One of the biggest factors in the quest to better wireless communication is cellular
call handoff, which in tum, is a function of geographic location. In this thesis, our
fundamental goal was to demonstrate the value addition brought forth by spatial data
visualization techniques for the analysis of geo-referenced data from two different
location tracking technologies: GPS and cellular systems. Through our efforts, we
unearthed some valuable and surprising insights from the data being analyzed that led to
interesting observations about the data itself as opposed to the entity, or entities, that the
data is supposed to describe. In doing so, we underscored the value addition brought forth
by spatial data visualization techniques even in the incipient stages of analysis of georeferenced
data from cellular networks. We also demonstrated the value of visualization
techniques as a verification tool to verify the results of analysis done through other
methods, such as statistical analysis.

This work discusses and compares two different approaches that design and implement a requirement for security in an application. The construction process followed for the security features determines how easily further changes can be accommodated, after the application has been built. How the problem is decomposed into modules, and when, determines if a solution or parts from the solution will be reusable without modification in the same application after changes have been made to address a new or altered requirement. Two construction perspectives are analyzed. In the first perspective, security features are embedded within the application design. In the second approach, the security design is separated from the rest of the application. For this latter implementation, an aspect oriented approach is used. The analysis performed shows that how the problem is decomposed leads to different designs, which present different levels of challenge for the application's future evolution. If a more adaptable solution can be designed and implemented, then the application will be more flexible to accommodate new changes and, as a consequence, be more reusable.