Cookies Policy
The website need some cookies and similar means to function. If you permit us, we will use those means to collect data on your visits for aggregated statistics to improve our service. Find out More
Accept Reject
  • Menu
Publications

Publications by HASLab

2004

A survey of formal methods courses in European higher education: The FME subgroup on education

Authors
Oliveira, JN;

Publication
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

Abstract
This paper presents a survey of formal methods courses in European higher education carried out by the FME Subgroup on Education over the last two years. The survey data sample is made of 117 courses spreading over 58 higher-education institutions across 13 European countries and involving (at least) 91 academic staff. A total number of 364 websites have been browsed which are accessible from the electronic (HTML) version of the paper in the form of links to course websites, lecturers and topic entries in encyclopedias or virtual libraries. Three main projections of our sample are briefly analysed. Although far from being fully representative, these already provide some useful indicators about the impact of formal methods in European curricula on computing. © Springer-Verlag 2004.

2004

Relational sampling for data quality auditing and decision support

Authors
Cortes, B; Oliveira, JN;

Publication
ICEIS 2004 - Proceedings of the Sixth International Conference on Enterprise Information Systems

Abstract
This paper presents a strategy for applying sampling techniques to relational databases, in the context of data quality auditing or decision support processes. Fuzzy cluster sampling is used to survey sets of records for correctness of business rules. Relational algebra estimators are presented as a data quality-auditing tool.

2004

Iransposing relations: From Maybe functions to hash tables

Authors
de Oliveira, JNF; Rodrigues, CJPC;

Publication
MATHEMATICS OF PROGRAM CONSTRUCTION, PROCEEDINGS

Abstract
Functional transposition is a technique for converting relations into functions aimed at developing the relational algebra via the algebra of functions. This paper attempts to develop a basis for generic transposition. Two instances of this construction are considered, one applicable to any relation and the other applicable to simple relations only. Our illustration of the usefulness of the generic transpose takes advantage of the free theorem of a polymorphic function. We show how to derive laws of relational combinators as free theorems of their transposes. Finally, we relate the topic of functional transposition with the hashing technique for efficient data representation.

2004

On semantics and refinement of UML statecharts: A coalgebraic view

Authors
Sun, M; Zhang, NX; Barbosa, LS;

Publication
PROCEEDINGS OF THE SECOND INTERNATIONAL CONFERENCE ON SOFTWARE ENGINEERING AND FORMAL METHODS

Abstract
Statecharts was conceived as a visual formalism for the design of reactive systems. UML statecharts is an object-based variant of classical statecharts, incorporating several concepts different from the classical statecharts. This paper discusses a coalgebraic description of UML statecharts, directly derived from its operational semantics. In particular such an approach induces suitable notions of equivalence and (behavioral) refinement for statecharts. Finally, a few refinement laws are investigated to support verifiable stepwise system development with statecharts.

2004

On refinement of generic state-based software components

Authors
Meng, S; Barbosa, LS;

Publication
ALGEBRAIC METHODOLOGY AND SOFTWARE TECHNOLOGY: PROCEEDINGS

Abstract
This paper characterizes refinement of state-based software components modelled as pointed coalgebras for some Set endofunctors. The proposed characterization is parametric on a specification of the underlying behaviour model introduced as a strong monad. This provides a basis to reason about (and transform) state-based software designs.

2004

A relational model for component interconnection

Authors
Barbosa, MA; Barbosa, LS;

Publication
JOURNAL OF UNIVERSAL COMPUTER SCIENCE

Abstract
The basic motivation of component based development is to replace conventional programming by the composition of reusable off-the-shelf units, externally coordinated through a network of connecting devices, to achieve a common goal. This paper introduces a new relational model for software connectors and discusses some preliminary work on its implementation in Haskell. The proposed model adopts a coordination point of view in order to deal with components' temporal and spatial decoupling and, therefore, to provide support for looser levels of inter-component dependency and effective external control.

  • 243
  • 260