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Project descriptions During
her visit, Raquel has been working on the following projects:
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Algorithms for answering spatial queries based on the data structure
of the MultiMap library
The purpose of the MultiMap library is to provide a data structure
and a set operators to support the representation and manipulation in primary
memory of plane maps in vector format and at multiple resolution. Basically,
the first layer of the library consists of:
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A data structure to represent plane maps in vector format at a single resolution;
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A set of operators that permit to traverse, build and modify such a data
structure;
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A set of spatial queries that can be implemented on top of such operators.
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A set of operators for performing model-oriented generalization through
seven topological primitives
Model-oriented generalization operations involving topological aspects
are selection, symbolisation and aggregation. Most of them
can be accomplished with seven topological primitives. Out of the scope
of such primitives are some common generalization operations that are not
consistent combinatorial transformations. Topological primitives point_
abstraction, line_abstraction, and line_merge accomplish
selection operations; line_to_point_ contraction, region_to_point_
contraction and region_to_line_contraction perform symbolisation
operations; and primitive region_merge corresponds to an aggregation
operation. The topological primitives act on simple entities. It should
be desirable to be able to handle the entities composing the map, some
of which, when dealing with maps modeled through a Plane Euclidean Graph,
are not simple, for example a region is allowed to have holes and features.
For constructing a generalized map from an original one, its corresponding
plane graph must be obtained by applying some composition of the seven
topological primitives to the original one. The developed macro-operators
correspond to common, and valid in our theoretical model, cartographical
operations needed when accomplishing model-oriented generalization.
Publications The following
technical reports summarize the work carried out during her stay:
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E.Puppo, R.Viaña Fernández, 2001,
"Designing the MultiMap
Library - Step 1: Representation and manipulation of plane vector
maps"
Technical Report
DISI-TR-01-14, University of Genova.
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E.Puppo, R.Viaña Fernandez, 2001,
"Designing the MultiMap
Library - Step 2: Model-oriented generalization
operators"
Technical Report
DISI-TR-01-15, University of Genova.
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