François Pinet

Precise modeling and verification of topological integrity constraints in spatial databases: from an expressive power study to code generation principles

Recent works underline that the integration of topological relationships into the Object Constraint Language (OCL) is an important field of investigation. The final goal is to provide an expressive language adapted to precisely model alphanumerical and topological constraints. In order to reach this goal, the present paper focuses on the integration of the 9 Intersection Method (9IM) into OCL. We show that this OCL+9IM language is especially suitable for the specification of topological constraints implying composite spatial objects. The expressive power of the language is also studied from a spatial point of view, and the SQL code generation from OCL+9IM expressions is considered. An important validation is related to the use of the language in the context of agricultural information systems.

Entity-relationship and object-oriented formalisms for modeling spatial environmental data

Entity-Relationship (ER) and Object-Oriented (OO) formalisms are often used to model environmental information of databases or computer programs. The majority of the environmental information is georeferenced. However, for 20 years, researchers have proposed different methods to adapt ER and OO to model spatial data. Spatial information is complex, and the goal is to simplify its representation in conceptual models. The goal of this paper is to propose a classification and a list of work in the area of ER and OO formalisms for spatial information. Numerous bibliographical references on the subject are also provided. The article targets mainly researchers working in the area of environment domain hoping to find a bibliographical entry to the subject. We present here a synthesis of the principal advances in the field.

Semantics of Stereotypes for Type Specification in UML: Theory and Practice

In the context of object-oriented formalism, stereotypes are presented as a new means for user-defined extensions of the Unified Modeling Language (UML). Unfortunately, the stereotypes syntax and semantics vary depending on the proposed extensions and it is not easy to propose a complete formalization of this mechanism. This is the reason why this paper tries to identify and formalize a pertinent set of stereotypes called stereotypes for type specification. This category of stereotypes was intuitively or implicitly presented in several works and has been experimented in different modeling methods, especially in the field of Geographic Information System (GIS). This paper proposes a complete study of this class of stereotypes and discusses the interest of their applications. Numerous examples will be presented in the field of GIS.

An Adverbial Approach for the Formal Specification of Topological Constraints Involving Regions with Broad Boundaries

Topological integrity constraints control the topological properties of spatial objects and the validity of their topological relationships in spatial databases. These constraints can be specified by using formal languages such as the spatial extension of the Object Constraint Language(OCL). Spatial OCL allows the expression of topological constraints involving crisp spatial objects. However, topological constraints involving spatial objects with vague shapes (e.g., regions with broad boundaries) are not supported by this language. Shape vagueness requires using appropriate topological operators (e.g., strongly Disjoint, fairly Meet) to specify valid relations between these objects; otherwise, the constraints cannot be respected. This paper addresses the problem of the lack of terminology to express topological constraints involving regions with broad boundaries. We propose an extension of Spatial OCLbased on a geometric model for objects with vague shapes and an adverbial approach for topological relations between regions with broad boundaries. This extension of Spatial OCLis then tested on an agricultural database.

Integrating the Calculus-Based Method into OCL: Study of Expressiveness and Code Generation

This paper aims at describing the integration of the calculus-based method (CBM) into the object constraint language (OCL) in order to facilitate the specification of topological constraints in spatial databases. A first study related to the expressiveness is presented, as well as a specific architecture for database trigger generation from OCL specification