The Core Gnosis system is now available for download, here.
“Executable modelling languages are important tools in science and engineering. They provide methods for exploring of systems that are too complex to be usefully described in simple, analytical terms.
It is very often difficult to validate such models of complex systems, and there are important questions about faithfulness of representation of the underlying system and of the degree to which such models can be predictive. A possible source of errors lies in the modelling language itself, because (contrary to the beliefs of many) languages are themselves complicated artifacts. It is very important to use a modelling language which is well-understood, both by its authors and by its users. This points towards the disciplined use of small, expressive, languages that have a formal semantics, that are implemented with a high-degree of integrity, and which employ constructs that naturally support the modelling idiom.
A landmark achievement was the construction of process modeling languages, particularly Simula (which extends Algol for modelling), which use the notion of concurrent processes to structure models. This was distilled into a small, expressive language called Demos by Birtwistle, which emphasizes the disciplined use of further structure, namely resource, by the processes.
In fields such as program logic, programming language semantics, and concurrency, the introduction of mathematical semantic methods has led to significant insights in expressiveness and improved reliability properties.
In the field of modelling and simulation, however, semantics has made relatively little impact. One significant and elegant exception to this situation is the work of Hillston and her colleagues, in which a process calculus is enriched with stochastic components, together with an account of its stochastic properties in terms of Markov chains. Hillston et al’s framework has been explored in detail, has tool support, and has been deployed in wide range of examples. Our approach differs in that we separate system semantics and modelling language, interpreting the latter in the former.
While the notion of process has been explored in some detail by the semantics community, concepts like resource have almost always been treated as second class. There are many advantages to doing this, from the point-of-view of a theorist. We take the opposite view. That is, we try to see what can be gained by developing an approach in which the structures present in applied modeling languages are given a rigorous treatment as first-class citizens in a theory. This has allowed us to develop our own disciplined approach to applied modelling and an associated tool Core Gnosis”
--- Posted by Marco Casassa Mont (here and here) ---
--- NOTE: use this mirror blog if you prefer posting on an external blog site ---
--- NOTE: my original HP blog can be found here ---
No comments:
Post a Comment