Visualizing City Events on Search Engine: Tword the Search Infrustration for Smart City

City big data play the central role in the whole smart city system architecture, where the search engine acts as the entrance to these big data. In this paper, we focus on the topic of events management in the city. By visualizing the search results beyond the traditional page-list manner, we can provide more valuable insight of the important events occurring in the city. Our development comprises three aspects: (i) the elementary representations of one city event. Here, two manners are proposed: one for the emergency event real time detecting & tracing, the other continuously aggregating the data to describe the event completely, (ii) the high order city event(s) representations, which extend along three directions: event summary, event drill-down and multi-events, (iii) the intelligent methods behind events visualization in the circumstance of heterogeneous data from IOT (internet of things) and web.