A Markov chain based pruning method for predictive range queries

Abstract

Predictive range queries retrieve objects in a certain spatial region at a (future) prediction time. Processing predictive range queries on large moving object databases is expensive. Thus effective pruning is important, especially for long-term predictive queries since accurately predicting long-term future behaviors of moving objects is challenging and expensive. In this work, we propose a pruning method that effectively reduces the candidate set for predictive range queries based on (high-order) Markov chain models learned from historical trajectories. The key to our method is to devise compressed representations for sparse multi-dimensional matrices, and leverage efficient algorithms for matrix computations. Experimental evaluations show that our approach significantly outperforms other pruning methods in terms of efficiency and precision.