Scielo RSS <![CDATA[Journal of the Brazilian Computer Society]]> vol. 6 num. 2 lang. pt <![CDATA[SciELO Logo]]> <![CDATA[<B>Letter from the editor in chief</B>]]> <![CDATA[<B>MIDIZ</B>: <B>content based indexing and retrieving MIDI files</B>]]> This paper presents a search engine for musical files in the Internet, based on the description of a musical passage, regardless of the key it is played in. Furthermore, the system allows some errors on the musical passage description, according to a parameter available in the interface. <![CDATA[<B>Automatic theory formation in graph theory</B>]]> This paper presents SCOT, a system for automatic theory construction in the domain of Graph Theory. Following on the footsteps of the programs ARE [9], HR [1] and Cyrano [6], concept discovery is modeled as search in a concept space. We propose a classification for discovery heuristics, which takes into account the main processes related to theory construction: concept construction, example production, example analysis, conjecture construction, and conjecture analysis. <![CDATA[<B>Interactive multistage simulation of goal-driven agents</B>]]> Multistage simulation is employed to help predicting the future actions of collaborating or competing agents, interacting in the mini-world covered by a temporal database. At each stage, their goals are inferred from the current situation, with the help of rules designed to model their behavioural patterns, in turn extracted from records of their past actions. Besides goal-inference rules, the simulation machinery adapts and combines plan-recognition and generation algorithms. The resulting environment is highly interactive, allowing the user to interfere in various ways. A prototype tool (IPG), implemented in Prolog augmented with constraint programming features, was developed and is being used to run experiments. <![CDATA[<B>Global database views in a federation of autonomous databases</B>]]> The Institute of Computer Science of the Federal University of Rio Grande do Sul is participating in a project to develop a computer system infrastructure for supporting the Brazilian health ministry’s SUS (Sistema Unificado de Saude) program. In order to construct this heterogeneous system, we have to start from existing information sources (possibly "legacy") and their services and gradually integrate them with new software and hardware architectures, guided by requirements evolution and technical innovations. This requires to combine distributed query processing with a service-based middleware framework as defined, e.g., by CORBA. This paper describes the conceptual and implementational aspects of the SUS-specific solution to this challenge.