\section{System Overview}


\input{pictures/system_overview}

The system is designed to collected data from many users. Figure \ref{system_overview} shows the system overview where each client is named as Smartphone. The client contains a local database. This database is periodically backup to a centralized server along with a anonymous unique identifier. The server then maintains the copies of the clients databases and periodically merges these into one big database, as indicated in figure \ref{system_overview}.
