Given a finite range space Î£ = (X, R), with N = |X| + |R|, we present two simple algorithms, based on the multiplicative-weight method, for computing a small-size hitting set or set cover of Î£. Theâ€¦ (More)

A fundamental problem in analyzing trajectory data is to identify common patterns between pairs or among groups of trajectories. In this paper, we consider the problem of matching similar portionsâ€¦ (More)

We present the first subquadratic algorithms for computing similarity between a pair of point sequences in R, for any fixed d > 1, using dynamic time warping (DTW) and edit distance, assuming thatâ€¦ (More)

Dynamic time warping (DTW) is a widely used curve similarity measure. We present a simple and efficient (1 + Îµ)- approximation algorithm for DTW between a pair of point sequences, say, P and Q, eachâ€¦ (More)

We develop continuous-time probabilistic models to study trajectory data consisting of times and locations of user â€˜check-insâ€™. We model the data as realizations of a marked point process, withâ€¦ (More)

Motivated by the increasing popularity of electric vehicles (EV) and a lack of charging stations in the road network, we study the shortest path hitting set (SPHS) problem. Roughly speaking, given anâ€¦ (More)

In this project, we study the network activation problem on planar graphs. In particular, we obtain a polynomial-time constant-approximation primal-dual algorithm for the Steiner forest activationâ€¦ (More)

We propose a model for subtrajectory clustering ---the clustering of subsequences of trajectories; each cluster of subtrajectories is represented as a pathlet, a sequence of points that is notâ€¦ (More)