Managing large distributed dynamic graphs for smart city network applications

Smart cities and traffic applications can be modelled by dynamic graphs for which vertices or edges can be added, removed or change their properties. In the smart city or traffic monitoring problem, we wish to detect if a city dynamic graph maintains a certain local or global property. Monitoring city large dynamic graphs, is even more complicated. To treat the monitoring problem efficiently we divide a large city graph into sub-graphs. In the distributed monitoring problem we would like to define some local conditions for which the global city graph G maintains a certain property. Furthermore, we would like to detect if a local city change in a sub-graph affect a global graph property. Here we show that turning the graph into a non-trivial one by handling directed graphs, weighted graphs, graphs with nodes that contain different attributes or combinations of these aspects, can be integrated in known urban environment applications. These implementations are demonstrated here in two types of network applications: traffic network application and on-line social network smart city applications. We exemplify these two problems, show their experimental results and characterize efficient monitoring algorithms that can handle them.