Jiangwei Pan

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Given a finite range space Σ = (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 Σ. The first algorithm is a simpler variant of the Brönnimann-Goodrich algorithm but more efficient to implement, and the second algorithm can be viewed(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 portions between a pair of trajectories, each observed as a sequence of points sampled from it. We present new measures of trajectory similarity --- both local and global(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 that the point sequences are drawn from certain natural families of curves. In particular, our algorithms compute (1 + ε)-approximations of DTW and ED in near-linear(More)
Dynamic time warping (DTW) is a widely used curve similarity measure. We present a simple and efficient (1 + <i>&#949;</i>)- approximation algorithm for DTW between a pair of point sequences, say, <i>P</i> and <i>Q</i>, each of which is sampled from a curve. We prove that the running time of the algorithm is O([EQUATION]n log <i>&sigma;</i>) for a pair of(More)
We develop continuous-time probabilistic models to study trajectory data consisting of times and locations of user ‘check-ins’. We model the data as realizations of a marked point process, with intensity and mark-distribution modulated by a latent Markov jump process (MJP). We also include user-heterogeneity in our model by assigning each user a vector of(More)
There are many real world scenarios which can be modeled as a security game where there is one player, called the defender, trying to protect a set of potential targets from another player, called the attacker. Game-theoretic security approaches are currently used to set up traffic checkpoints and canine patrols at LAX airport [38, 37], to assign Federal(More)
We develop continuous-time probabilistic models to study trajectory data consisting of times and locations of user ‘check-ins’. We model these as realizations of a marked point process, with intensity and mark-distribution modulated by a latent Markov jump process (MJP). We extend this Markov-modulated marked Poisson process to include user-heterogeneity by(More)
Given a stream of items each associated with a numerical value, its edit distance to monotonicity is the minimum number of items to remove so that the remaining items are non-decreasing with respect to the numerical value. The space complexity of estimating the edit distance to monotonicity of a data stream is becoming well-understood over the past few(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 an input graph G, the goal is to compute a small-size subset H of vertices of G such that by placing charging stations at vertices in H, every shortest path in G(More)
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