Current spatial database systems offer limited querying capabilities beyond topological relations. This paper introduces a model for projective relations between regions to support other qualitative spatial queries. The relations are ternary because they are based on the collinearity invariant of three points under projective geometry. The model is built on a partition of the plane in five regi...

Detailed information about geology, hydrogeology and seismic hazard issues for Umbria region are contained in a spatial database available as open data format (shapefile or KMZ) and distributed under the regional open data portal called Open Data Umbria ( http://dati.umbria.it ) where 297 datasets have been produced by Umbria Region until now and most of them are made by Geological Survey. Geol...

Querying heterogeneous spatial databases involves not only characterizing and comparing the information content of several databases, but also navigating or accessing the data sets with the query answer. This work proposes a formalism that relates the information content of data sets by three basic types of correspondence relations: data equivalence, difference of data omission, and difference ...

This paper describes the incremental behaviours of Density based clustering. It specially focuses on the Density Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm and its incremental approach.DBSCAN relies on a density based notion of clusters.It discovers clusters of arbitrary shapes in spatial databases with noise.In incremental approach, the DBSCAN algorithm is applied t...

Children under the age of five constitute around 7% of the total U.S. population, and represent a segment of the population that is totally dependent on others for day-to-day activities. A significant proportion of this population spends time in some form of day care arrangement while their parents are away from home. Accounting for those children during emergencies is of high priority, which r...