COMPUTATIONAL MODELING SYSTEMS

A computational modeling system (CMS) provides scientific investigator s with a unified computational environment and easy access to a broad range of modeling tools. The goal of a CMS is to provide computational support that increases the efficiency of scientists in the iterative process of modeling. A CMS consists of a computational modeling enviro nment and transparent computational support for the environment. The m odeling environment is based on a characterization of scientific model ing activities that is focussed on the manner in which scientific conc epts are represented, manipulated, and evaluated, in the scientific mo deling process. Based on a formalization of the representation for a c oncept as representational structures (or ''R-structures''), the proce ss of scientific modeling may be viewed as one in which (1) extensible collections R-structures are constructed, evaluated and applied in mo deling both the phenomena in specific application domains and the phen omena of the modeling process itself; and (2) instances of the domain elements of R-structures are created and sequences of transformations are applied to the instances. R-structures provide a ''complete'' and consistent foundation for both the modeling environment of a CMS and i ts associated, high-level computational modeling language (CML). CML m ay be employed in creating, accessing, and manipulating R-structures a nd their components in a simple, uniform manner. A CMS provides a unif ying framework for the integration of existing tools, such as DBMS and mathematical software modules, and a distributed modeling environment . Based on the general specification of a CMS, we have designed and im plemented a specific CMS, Amazonia, which supports earth science appli cations in terms of a specific set of R-structures and a ''seamlessly' ' integrated and extendable collection of computational modules, inclu ding an object-oriented DBMS.