Efficient Computation of Range Aggregates Against Uncertain Location Based Queries in Multi Dimensional Space

Abstract

In many applications, including location based services, queries may not be precise. In this paper, we study the problem of efficiently computing range aggregates in a multidimensional space when the query location is uncertain. Specifically, for a query point Q whose location is uncertain and a set S of points in a multi-dimensional space, we want to calculate the aggregate (e.g., count, average and sum) over the subset SI of S, Q has at least probability theta within the distance gamma to p. We propose novel, efficient techniques to solve the problem following the filtering-and-verification paradigm. In particular, two novel filtering techniques are proposed to effectively and efficiently remove data points from verification. Our comprehensive experiments based on both real and synthetic data demonstrate the efficiency and scalability of our techniques.