Handling Knowledge Over Moving Object Trajectories Using Formal Concept Analysis

We define the term semantic trajectories of moving objects as a sequence of spatio-temporal points with associated semantic information. Spatio-temporal points are directly generated by sensors that capture the position of a moving object in time. In this paper, we work on a marine mammal trajectory case study. We consider the seals' trajectories to understand their behavior within groups and identify their activities simultaneously in the same place. We define the activities of mobile objects in the form of rules given by the domain expert. To gain knowledge of trajectories, we use the GALACTIC platform, which is a new platform based on Formal Concept Analysis (FCA) for computing a concept lattice from heterogeneous and complex data. Data in GALACTIC are described by predicates according to their types. Here, we will use interval sequence plugins to analyse the trajectories of seals, where interval sequences are represented by a set of time intervals in which a seal performs an activity in a geographical zone. Finally, the results show the simultaneous activities of a group of seals.