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| creator |
Lange, Ralph
| | Farrell, Tobias
| | Dürr, Frank
| | Rothermel, Kurt
| | date |
2009-03
| | | | description |
Moving objects databases (MODs) have been proposed for managing
trajectory data, an important kind of information for pervasive
applications. To save storage capacity, a MOD generally stores
simplified trajectories only. A simplified trajectory approximates
the actual trajectory of the mobile object according to a certain
accuracy bound. In order to minimize the costs of communicating
position information between mobile object and MOD, the trajectory
simplification should be performed by the mobile object. To assure
that the MOD always has a valid simplified trajectory of the remote
object, we propose the generic remote trajectory simplification
protocol (GRTS) allowing for computing and managing a simplified
trajectory in such a system in real-time. We show how to combine
GRTS with existing line simplification algorithms for computing the
simplified trajectory and analyze trade-offs between the different
algorithms. Our evaluations show that GRTS outperforms the two
existing approaches by a factor of two and more in terms of
reduction efficiency. Moreover, on average, the reduction efficiency
of GRTS is only 12% worse compared to optimal offline
simplification.
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