No abstract

A workshop on temporal relations in Geographic Information Systems (GIS) was held on October 12-13, 1990, at the University of Maine. The meeting, sponsored by the National Center for Geographic Information and Analysis (NCGIA), gathered specialists on Geography, GIS, and Computer Science to discuss users' requirements of temporal GIS and to identify the corresponding research issues.

This article presents a system to enable access to those Information Systems at the National Autonomous University of Mexico (UNAM) that are related to Biodiversity and the Environment. The system in question associates existing Geographic Information Systems (GIS’s) as well as standard relational databases in a federation, allows the contents of the individual GIS (or relational databases) to be consulted in a manner transparent to the user, and permits the exports of the underlying systems’ data under the corresponding set of permissions. Our approach is based upon three principles: compliance with international standards, reliance upon Open Source Software in implementation, and usage of servers of proven reliability and robustness.

This paper describes a system to enable access to those information systems at the National Autonomous University of Mexico that are related to biodiversity and the environment. This system associates existing Geographic Information Systems, Biodiversity Information Systems, and standard Relational Database Management Systems in a federation. In this way, the system enables researchers to retrieve information using a single query interface, in a format suitable for their particular field of study, and according to a corresponding set of permissions. The main contribution of this paper is to propose an open-sourced Mediator system compliant with open international standards. This system offers a competitive performance against state of the art Relational Database Management Systems in spatial and non-spatial join operations.Index Terms-mediator system, geospatial information system, biodiversity information system, information system federation, query system

This article presents a system to enable access to those Information Systems at the National Autonomous University of Mexico (UNAM) that are related to Biodiversity and the Environment. The system in question associates existing Geographic Information Systems (GIS’s) as well as standard relational databases in a federation, allows the contents of the individual GIS (or relational databases) to be consulted in a manner transparent to the user, and permits the exports of the underlying systems’ data under the corresponding set of permissions. Our approach is based upon three principles: compliance with international standards, reliance upon Open Source Software in implementation, and usage of servers of proven reliability and robustness. [Article copies are available for purchase from InfoSci-on-Demand.com]