Cost and imprecision in modeling the position of moving objects

Abstract

Consider a database that represents the location of moving objects, such as taxi-cabs typical query: retrieve the cabs that are currently within 1 mile of 33 Michigan Ave., Chicago, or objects in a battle-eld. Existing database management systems DBMS's are not well equipped to handle continuously changing data, such as the position of moving objects, since data is assumed t o b e c onstant unless it is explicitly modied.In this paper we address position-update policies and imprecision. Namely, assuming that the actual position of a moving object m deviates from the position computed by the DBMS, when should m update its position in the database in order to eliminate the deviation? Furthermore, how can the DBMS provide a bound on the error i.e. the deviation when it replies to a query: what is the current position of m? We propose a cost based approach to update policies that answers both questions. We develop several update policies and analyze them theoretically and experimentally.

Modeling and Querying Moving Objects with Social Relationships

“…getnodes(mo, lk s ) (32) Benefitting from this graph structure, many query operations become more convenient than traditional relational database solution. For instance, the basic query 'finding all David's friends' needs many table-joint operations in the traditional table approach.…”

“…For example, the moving objects spatio-temporal (MOST) data model allowed the management of the current position of moving objects, and the prediction of future movement based on an important concept of the dynamic attribute that values change over time according to a given function of time [31][32][33]. Forlizzi et al provided a discrete model for the abstract model presented by Guting and co-workers [34,35].…”

The Geometry of Uncertainty in Moving Objects Databases

“…As for uncertainty issues, Wolfson et al [36,37] introduce a cost based approach to determine the size of the uncertainty area (r in this paper). However, linguistic and querying aspects are not addressed in these papers.…”

“…Aside from a purely spatial ( [8] surveys 50+ structures) and temporal databases [27], there are several recent results which tackle various problems of indexing spatio-temporal objects and dynamic attributes [1,12,13,17,22,28,30,31]. Representing and querying the location of moving objects as a function of time is introduced in [24], and the works in [36,37] address policies for updating and modeling imprecision and communication costs. Modeling and querying location uncertainties due to sampling and GPS imprecision is presented in [16].…”

Main Memory Evaluation of Monitoring Queries Over Moving Objects

“…The problem of answering a range query for a collection of moving objects is addressed in [2] through the use of indexing schemes using external range trees. [28] and [30] consider the management of collections of moving points in the plane by describing the current and expected positions of each point in the future. They address how often to update the locations of the points to balance the costs of updates against imprecision in the point positions.…”