Abstract. Including semantic information in models helps to expose modeling errors early in the design process, engage a designer in a deeper understanding of the model, and standardize concepts and terminology across a development team. It is impractical, however, for model builders to manually annotate every modeling element with semantic properties. This paper demonstrates a correct, scalable and automated method to infer semantic properties using lattice-based ontologies, given relatively few manual annotations. Semantic concepts and their relationships are formalized as a lattice, and relationships within and between components are expressed as a set of constraints and acceptance criteria relative to the lattice. Our inference engine automatically infers properties wherever they are not explicitly specified. Our implementation leverages the infrastructure in the Ptolemy II type system to get efficient and scalable inference and consistency checking. We demonstrate the approach on a non-trivial Ptolemy II model of an adaptive cruise control system.

Embedded software requires concurrency formalisms other than threads and mutexes used in traditional programming languages like C. Actor-oriented design presents a high level abstraction for composing concurrent components. However, high level abstraction often introduces overhead and results in slower system. We address the problem of generating efficient implementation for the systems with such a high level description. We use partial evaluation as an optimized compilation technique for actor-oriented models. We use a helper-based mechanism, which results in flexible and extensible code generation framework. The end result is that the benefit offered by high level abstraction comes with (almost) no performance penalty. The code generation framework has been released in open source form as part of Ptolemy II 6.0.1.