@article {Moreira:1999:1523-0406:109,
	author = "Moreira, Jose and Ribeiro, Cristina and Saglio, Jean-Marc",
	title = "Representation and Manipulation of Moving Points: An Extended Data Model for Location Estimation",
	journal = "Cartography and Geographic Information Science",
	volume = "26",
	number = "2",
	year = "1999",
	abstract = "In this paper we introduce a classification for spatio-temporal systems based on the properties of the represented objects. Building on this classification, we assert that complex objects can be derived from simpler ones, following an evolutionary approach which starts with the study of simple objects and ends by enriching them with new features. This paper focuses on the definition of a data model for the representation of moving points. The model is based on the decomposition of the trajectory of moving points into sections. The movement within each section of a trajectory is described by a variability function. Because for most systems it is not possible to store the exact knowledge about the movement of an object, the answers to queries may be imprecise. We propose two additional approaches to deal with imprecision—the superset and the subset semantics—based on a maximum value for the variability function, and a smooth technique to integrate them in the model. Finally, we analyze certain functional aspects of the implementation of the data model in a Relational Database Management System (RDBMS) and outline directions for future research.",
	pages = "109-124",
	url = "http://www.ingentaconnect.com/content/cagis/cagis/1999/00000026/00000002/art00004",
	doi = "doi:10.1559/152304099782330725",
	keyword = "SPATIO-TEMPORAL SYSTEMS, MOVING POINTS, CONTINUOUS CHANGE, GEOGRAPHIC INFORMATION SYSTEMS (GIS)"
}