Innovative Software Development in GIS

Chapter 4

Spatiotemporal Knowledge Representation in AROM-ST

4.1. Introduction

Arising from frame languages [MIN 75], close to description logics [BAA 03] and ontological languages [MCG 04], object-oriented knowledge representation systems (also known as OOKRS) [DUC 98, NAP 04] describe, organize, and store knowledge by relying on the general principles of the object paradigm (notions of class, instance, specialization hierarchy). They have various inference mechanisms (inheritance, procedural attachment, filtering, classification) that allow them to clarify the knowledge and fill in any missing pieces.

Among the various OOKRS, AROM (an acronym for “Allier Relations et Objets pour Modéliser” (Ally Relations and Objects to Model) [PAG 00]) is distinctive due to its two core complementary representation structures – classes and associations, like the entities used in UML class diagrams. Another particularity of AROM is the presence of an algebraic modeling language (AML). AMLs (AMPL¹, LINGO²) offer to represent equation, constraint, or query systems due to a formalism close to notations generally used in mathematics.

In AROM, the AML allows us to build algebraic expressions integrating the base types, managed by the system, and their associated operators, which considerably increases the system's expressiveness, defined as its description power in knowledge expression.

Indeed, these algebraic expressions allow us not only to formulate queries on an AROM knowledge base, but also to ...