Abstract
Assuring Quality of Service (QoS) properties is critical in the development of component-based distributed systems. This paper presents an approach to introduce QoS constraints into a coalgebraic model of software components. Such constraints are formally captured through the concept of a Q-algebra which, in its turn, can be smoothly integrated in the definition of component combinators. © 2010 ACM.

Abstract
Current software development often relies on non-trivial coordination logic for combining autonomous services, eventually running on different platforms. As a rule, however, such a coordination layer is strongly woven within the application at source code level. Therefore, its precise identification becomes a major methodological (and technical) problem and a challenge to any program understanding or refactoring process. The approach introduced in this paper resorts to slicing techniques to extract coordination data from source code. Such data are captured in a specific dependency graph structure from which a coordination model can be recovered either in the form of an ORC specification or as a collection of code fragments corresponding to the identification of typical coordination patterns in the system. Tool support is also discussed.

Abstract
Research in formal methods emphasizes a fundamental interconnection between modeling, calculation and prototyping, made possible by a common unambiguous, mathematical semantics. This paper, building on a broader research agenda on coalgebraic semantics for Unified Modeling Language diagrams, concentrates on class diagrams and discusses how such a coalgebraic perspective can be of use not only for formalizing their specification, but also as a basis for prototyping. © Springer-Verlag London Limited 2009.

Abstract

Abstract
Despite its huge success and increasing incorporation in complex, industrial-strength applications, open source software, by the very nature of its open, unconventional, distributed development model, is hard to assess and certify in an effective, sound and independent way. This makes its use and integration within safety or security-critical systems, a risk. And, simultaneously an opportunity and a challenge for rigourous, mathematically based, methods which aim at pushing software analysis and development to the level of a mature engineering discipline. This paper discusses such a challenge and proposes a number of ways in which open source development may benefit from the whole patrimony of formal methods.

Abstract
In this paper we present a technique to derive rules describing contrast sets. Contrast sets are a formalism to represent groups differences. We propose a novel approach to describe directional contrasts using rules where the contrasting effect is partitioned into pairs of groups. Our approach makes use of a directional Fisher Exact Test to find significant differences across groups. We used a Bonferroni within-search adjustment to control type I errors and a pruning technique to prevent derivation of non significant contrast set specializations.