This page shows all publications that appeared in the IASI annual research reports. Authors currently affiliated with the Institute are always listed with the full name.

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Show all publications of the year  2000, with author Pourabbas E., in the category IASI Research Reports (or show them all):

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IASI Research Report n. 530  (Next)  

Pourabbas E., Rafanelli M.

A pictorial query language extended with cardinal and positional operators for querying geographic databases

ABSTRACT

In the context of geographic information systems the spatial relationships between two geographic objects play a central role at the query processing level. In this paper, we study particular spatial relationships, and we define and discuss a set of operators need to formulate queries in the context of a declarative pictorial query language which enlarge a previously proposed algebra. Such operators refer to the position of an object with respect to another one, their cardinal points, and consider specific geographic situations (e.g., water flow). We define and formalize also a set of specializations for the cardinal operators defined by prefixes completely, only, partially, and also. This language that is able to express queries on an object-oriented geographic database drawing the features which form the query is extended with respect to a previous one by cardinal and positional operators. Moreover, the main characteristics of the pictorial query language using the above mentioned operators through some query examples are shown.