Representation of generalized map series using semi-structured data models

Large cartographic organizations worldwide produce generalized map series (GMS) in order to meet various user requirements. A GMS consists of maps of the same geographic region at different scales. Most of these maps currently are designed in a digital environment, and recently some of them have been distributed through the web. One important issue is the appropriate modeling and handling of cartographic entities composing individual maps in a GMS. Since these entities have rather complex descriptions and may be provided by various agencies, they usually do not conform to a fixed schema (i.e., they do not have a common structure). Hence, their representation in traditional data models, such as the relational or object-oriented, is not always feasible. This paper investigates the use of semi-structured data (SSD) models--an innovative approach recently developed in Information Technology for representing and handling entities in a GMS. Specifically, the Object Exchange Model (OEM), a popular database model for SSD, has been adopted to represent a GMS. How useful information can be extracted from such a representation using the LOREL query language--a popular language for SSD--is also shown. KEYWORDS: Map generalization, generalized map series (GMS), semi-structured data (SSD), Object Exchange Model (OEM), Lightweight Object REpository (LORE) system, LORE query Language (LOREL).
Introduction Information Technology (IT) scientists recently have focused their efforts on developing innovative methodologies for modeling and handling semi-structured data (SSD) in order to enhance the efficiency of software systems [...]