Júlio Henrique Araújo Pereira Machado

Hyper-Automation System Applied to Geometry Demonstration Environment

This paper describes the conception and implementation of a learning system on Euclidean Geometry demonstrations and its knowledge base. We use the formalism of finite automata with output to represent and ordain the statements that constitute a geometric demonstration in the knowledge base. The system is built on the MOSCA learning protocol, based on learning with the assistance of examples and interaction among five agents (Mestre, Oraculo, Sonda, Cliente and Aprendiz) involved in the learning process. We briefly revise the Hyper-Automaton concept as a structural model for hypertext and its use as the basis for the central core of the agents in a learning system is analyzed.

Mapping Nautilus language into java: Towards a specification and programming environment for distributed systems

This paper describes some of the features of Nautilus specification/ programming language that make it interesting to develop complex systems and then explains how to map a Nautilus construction into Java constructions. The Nautilus constructions presented are: actions (including nondeterminism and intra-action concurrency), aggregations and refinements.

Nautilus, a Concurrent Diagrammatic Specification and Programming Language

Nautilus is a high-level specification and programming language having abstraction mechanisms not commonly found in other programming languages inspired by its semantic domain (a categorial model named Nonsequential Automata). It constitutes an elegant solution for concurrency and non-determinism as well as for synchronization of concurrent systems. The role as specification language highlights the diagrammatic syntax (it was originally text based).The diagrammatic syntax for Nautilus allows complete programs to be written using symbols and graphical diagrams. The graphical notation was elaborated in order to be able to express all the structures in the language, yet trying to improve the visualization of written programs. A brief comparison with UML is included. To support Nautilus as a programming language, a mapping to Java is constructed, setting the basis for an execution environment of Nautilus specifications.

Composing transitions into transactions in UML diagrams

When modeling concurrent or parallel systems, we must be aware that basic activities of each system may be constituted by smaller activities, i.e. transitions may be conceptually refined into transactions. Nevertheless, the Unified Modeling Language seems to lack compositional constructs for defining atomic actions/activities/operations. We discuss proper extensions for UML behavioral diagrams that are able to cope with the concept of transaction. Transactions are formally defined through a special morphism between automata in a semantic domain called Nonsequential Automata.