Mutation of Directed Graphs -- Corresponding Regular Expressions and Complexity of Their Generation

Directed graphs (DG), interpreted as state transition diagrams, are traditionally used to represent finite-state automata (FSA). In the context of formal languages, both FSA and regular expressions (RE) are equivalent in that they accept and generate, respectively, type-3 (regular) languages. Based on our previous work, this paper analyzes effects of graph manipulations on corresponding RE. In this present, starting stage we assume that the DG under consideration contains no cycles. Graph manipulation is performed by deleting or inserting of nodes or arcs. Combined and/or multiple application of these basic operators enable a great variety of transformations of DG (and corresponding RE) that can be seen as mutants of the original DG (and corresponding RE). DG are popular for modeling complex systems; however they easily become intractable if the system under consideration is complex and/or large. In such situations, we propose to switch to corresponding RE in order to benefit from their compact format for modeling and algebraic operations for analysis. The results of the study are of great potential interest to mutation testing

Modelling Metrics for Transparency in Medical Systems

Transparency is a novel non-functional requirement for software systems. It is acclaimed to improve the quality of service since it gives users access to information concerning the system’s processes, clarifying who is responsible if something goes wrong. Thus, it is believed to support people’s right to a secure and private processing of their personal data. We define eight quality metrics for transparency and we demonstrate the usage and the effectiveness of the metrics by assessing transparency on the Microsoft HealthVault, an on-line platform for users to collect, store, and share medical records