Crowd behavior analysis is an important field of research in modern world. It has wide applications in surveillance and public safety which are one of the prime social concerns. One way to analyze crowd behavior is obtain crowd movement data and then find out outliers in the individual trajectories to infer any abnormal behavior in the crowd.
Process Query Language (PQL) is a special-purpose programming language for managing process models based on information about process instances that these models describe. PQL is based upon temporal logic and adopts the concrete syntax of SQL.