Dagstuhl Seminar Proceedings, Volume 7212
Dagstuhl Seminar Proceedings
DagSemProc
https://www.dagstuhl.de/dagpub/1862-4405
https://dblp.org/db/series/dagstuhl
1862-4405
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
7212
2007
https://drops.dagstuhl.de/entities/volume/DagSemProc-volume-7212
07212 Abstracts Collection – Constraint Databases, Geometric Elimination ang Geographic Information Systems
From 20.05. to 25.05., the Dagstuhl Seminar 07212 ``Constraint Databases, Geometric Elimination and Geographic Information Systems'' was held
in the International Conference and Research Center (IBFI),
Schloss Dagstuhl.
During the seminar, several participants presented their current
research, and ongoing work and open problems were discussed. Abstracts of
the presentations given during the seminar as well as abstracts of
seminar results and ideas are put together in this paper. The first section
describes the seminar topics and goals in general.
Links to extended abstracts or full papers are provided, if available.
Constraint databases
geometric elimination
quantier elimination algorithms
geographic information systems
1-9
Regular Paper
Bernd
Bank
Bernd Bank
Max J.
Egenhofer
Max J. Egenhofer
Bart
Kuijpers
Bart Kuijpers
10.4230/DagSemProc.07212.1
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07212 Manifesto – Constraint Databases, Geometric Elimination ang Geographic Information Systems
During the last two decades the topic of constraint databases has evolved into a mature area of computer science with sound mathematical foundations and with a profound theoretical understanding of the expressive power of a variety of query languages. Constraint databases are especially suited for applications in which possibly infinite sets of continuous data, that have a geometric interpretation, need to be stored in a computer. Today, the most important application domains of constraint databases are geographic information systems (GIS), spatial databases and spatio-temporal databases. In these applications infinite geometrical sets of continuous data are finitely represented by means of finite combinations of polynomial equality and inequality constraints that describe these data sets (in mathematical terms these geometrical data sets are known as semi-algebraic sets and they have been extensively studied in real algebraic geometry). On the other hand, constraint databases provide us with a new view on classic (linear and nonlinear) optimization theory.
Constraint databases
elimination procedures
geographical information systems
1-7
Regular Paper
Bernd
Bank
Bernd Bank
Max J.
Egenhofer
Max J. Egenhofer
Joos
Heintz
Joos Heintz
Bart
Kuijpers
Bart Kuijpers
Peter
Revesz
Peter Revesz
10.4230/DagSemProc.07212.2
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A lower bound for the complexity of linear optimization from a quantifier-elimination point of view
We discuss the impact of data structures in quantifier elimination.
We analyze the arithmetic complexity of the feasibility problem in
linear optimization theory as a quantifier-elimination problem. For
the case of polyhedra defined by $2n$ halfspaces in $mathbb{R}^n$ we prove
that, if dense representation is used to code polynomials, any
quantifier-free formula expressing the set of parameters describing
nonempty polyhedra has size $Omega(4^{n})$.
Quantifier elimination
dense representation
instrinsic
lower bound
1-6
Regular Paper
Rafael
Grimson
Rafael Grimson
10.4230/DagSemProc.07212.3
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An analytic solution to the alibi query in the bead model for moving object data
Moving objects produce trajectories, which are stored in databases by means of finite samples of time-stamped locations. When
also speed limitations in these sample points are known,
beads can be used to model the
uncertainty about the object's location in between sample points.
In this setting, a query of particular interest, that has been
studied in the literature of geographic information systems (GIS),
is the alibi query. This boolean query asks whether two
moving objects can have physically met. This adds up to deciding
whether the necklaces of beads of these objects intersect. This
problem can be reduced to deciding whether two beads intersect.
Since, existing software to solve this problem fails to answer this
question within a reasonable time, we propose an analytical solution
to the alibi query, which can be used to answer the alibi query in
constant time, a matter of milliseconds or less, for two single
beads and in time proportional to the product of their lengths for
necklaces of beads.
Beads
uncertainty
alibi
query
solution
quantifier elimination
constraint database
1-22
Regular Paper
Bart
Kuijpers
Bart Kuijpers
Walied
Othman
Walied Othman
10.4230/DagSemProc.07212.4
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Checking the Integrity of Spatial Integrity Constraints
Integrity constraints play a major role when the quality of spatial data is checked by automatic procedures. Nevertheless the possibilities of checking the internal consistency of the integrity constraints themselves are hardly researched jet. This work analyses the applicability of reasoning techniques like the composition of spatial relations and constraint satisfaction in networks of constraints to find conflicts and redundancies in sets of spatial semantic integrity constraints. These integrity rules specify relations among entity classes. Such relations must hold to assure that the data is fitting to the semantics intended by the data model. For spatial data many semantic integrity constraints are based on spatial properties described for example through qualitative topological or metric relations. Since integrity constraints are defined at the class level, the reasoning properties of these spatial relations can not directly be applied. Therefore a set of class relations has been defined which, combined with the instance relations, enables for the specification of integrity constraints and to reason about them.
Semantic Integrity Constraints
Spatial Relations
Class Level Relations
Reasoning
Consistency of Constraints
Constraint Networks
1-9
Regular Paper
Stephan
Mäs
Stephan Mäs
10.4230/DagSemProc.07212.5
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Constraint Databases and Geographic Information Systems
Constraint databases and geographic information systems share many applications. However, constraint databases can go beyond geographic information systems in efficient
spatial and spatiotemporal data handling methods and in advanced applications. This survey mainly describes ways that constraint databases go beyond geographic information systems. However, the survey points out that in some areas constraint databases can learn also from geographic information systems.
Constraint databases
geographic information systems
moving objects
spatiotemporal data
visualization
1-9
Regular Paper
Peter
Revesz
Peter Revesz
10.4230/DagSemProc.07212.6
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