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... , the score of the route is defined as ~(}) = ∑ (} ) p , where (} ) = 9 |⋃ >|g r → g r8 ∈ ? 9 p |. For each cell sequence, we first search for the top-k local routes between any two consecutive cells in the cell sequence (e.g., g and g ' ) by an A*-like routing algorithm. However, a possible maximum speed could be derived from historical uncertain trajectories or be determined by difference applications. Given a maximum speed, possible positions between any two consecutive query locations can be restricted in a range if a time interval between the two locations is specified [11]. That is, the possible routes are restricted in the cells overlapping the range. For the A*- like routing algorithm, an estimated score of a route from a cell g to a cell g' is represented as follows. Given two cells g and g', a current visited cell g'', and a specified range r, an estimated score of a route }:} ⟶ } from a cell g to a cell g' in a specified range r is ~(}) = (}) + ℎ/}0, where } is a known route from cell g to cell g'', and ℎ/}0 is the score of an estimated route } from cell g'' to cell g'. Definition 8 (Optimal score): Given a graph e = (f,g) , an uncertain trajector...

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...om the authors’ knowledge, little existing work has been done to achieve our goal. The uncertainty of trajectories in a free 2D space has been studied intensively, as shown in [9], [6], [8] , [4] and =-=[7]-=-. Given the maximum speed of a moving object, the above approaches will show an uncertain region enclosing all possible locations while specific routes are not inferred. The approaches of mining GPS t...

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...Section 9 reports the experimental results. Finally, Section 10 concludes the paper. 2 Related Work 2.1 Modeling Moving Objects In the database literature, there has been a large body of recent works =-=[53, 20, 46, 52, 22, 44, 10, 13, 35, 18, 29, 37, 38, 27, 25]-=- on modeling moving objects. But all of them deal with the movement in one environment and do not investigate transportation modes. The closest to our work is [10, 35, 18] where the models consider th...

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...P-prediction for determining a region’s future center point. An interesting approach to modeling future movements of more complex spatial objects has been proposed recently by Praing and Schneider in =-=[82]-=-. The focus in this approach, however, is more on respective data types and query components, and only a general confidence distribution is proposed for modeling future positions of objects but no com...

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... models and prediction methods and tries to establish an abstract model as a conceptual basis in the area. However, a confident moving objects data model, called “Balloon” model, is proposed in [12], =-=[13]-=-. This model deals with spatiotemporal changes, it provides an integrated support for both historical and future movements of moving objects. The “Balloon” model describes basic ideas presented in [11...