Showing papers by "Luís Soares Barbosa published in 2010"
TL;DR: The approach introduced in this paper resorts to slicing techniques to extract coordination data from source code to recover a coordination model 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.
8 citations
Journal Article•
TL;DR: A number of ways in which open source development may benefit from the whole patrimony of formal methods are proposed.
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.
5 citations
15 Feb 2010
TL;DR: A calculus of component composition is extended to deal, in an effective way, with QoS constraints, and particular emphasis is put on how the laws that govern composition can be derived, in a calculational, pointfree style, in this new model.
Abstract: Component’s QoS constraints cannot be ignored when composing them to build reliable loosely-coupled, distributed systems. Therefore they should be explicitly taken into account in any formal model for component-based development. Such is the purpose of this paper: to extend a calculus of component composition to deal, in an effective way, with QoS constraints. Particular emphasis is put on how the laws that govern composition can be derived, in a calculational, pointfree style, in this new model.
3 citations
22 Mar 2010
TL;DR: This paper presents an approach to introduce QoS constraints into a coalgebraic model of software components through the concept of a Q-algebra which, in its turn, can be smoothly integrated in the definition of component combinators.
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.
3 citations
01 Jan 2010
TL;DR: The aim of the present work is to frame logics and interpretations along the lines of the coalgebraic perspective forward in Palmigiano's theory of abstract logic, as well as to study how refinements can be witnessed by logical interpretation.
Abstract: The concept of logic or deductive system is transversal in computer science. Several notions have been proposed on the literature, some of them, highly abstract in order to capture a wide class of logics. An interesting one is the formalization of a logic as an algebra together with a closure operator over that universe (or, equivalently, as an algebra together with a closure system over its universe (eg. [2])). Palmigiano in [6] related this theory of abstract logic with the theory of coalgebras, another central field in computer science. She shows that an abstract logic can be represented as a C -coalgebra over Set with C the closure system contravariant functor; moreover the coalgebraic morphisms are the strict morphisms between the correspondent original logics, i.e., algebraic morphisms such that the pre-images of closed sets of the target logic are exactly the closed sets of the source logic. In the context of algebraic specification refinement, we came recently interested in relating “equivalent logics” by maps which fail to be signature morphisms, in particular, in [3] and [4], we have studied how refinements can be witnessed by logical interpretation. A logical interpretation is a multifunction f that preserves consequence in the following sense: given two logics A = 〈A,CA〉 and B = 〈B,CB〉, for all {x}∪X ⊆ A, x ∈ CA([X ]) iff f (x) ⊆ CB( f [X ]). A paradigmatic example of an interpretation, is multifunction τ : Fm(Bool)→ Fm(CPC) from boolean equations to propositional terms defined, for any φ ≈ φ ′ ∈ Fm(Bool), by τ(φ ≈ φ ′) = {φ → φ ′,φ ′→ φ}. The aim of the present work is to frame logics and interpretations along the lines of the coalgebraic perspective forward in [6].
01 Jan 2010
TL;DR: In the brave, new world of Information Society, mathematical literacy became a condition for democratic citizenship as discussed by the authors and skills as basic as the ability to think and reason in terms of abstract models and the effective use of logical arguments and mathematical calculation in normal, daily business practice are on demand.
Abstract: In the brave, new world of Information Society, mathematical literacy became a condition for democratic citizenship. Actually, skills as basic as the ability to think and reason in terms of abstract models and the effective use of logical arguments and mathematical calculation in normal, daily business practice are on demand. Actually this concerns not only highly skilled IT professionals, who are expected to successfully design complex systems at ever-increasing levels of reliability and security, but also specialised workers monitoring, for example, CNC machines.
23 Sep 2010
TL;DR: This paper introduces a model in which context awareness is suitably handled and revisits the problem of specification of software connectors through which context dependent behaviour is correctly propagated.
Abstract: Software connectors are external coordination devices which ensure the flow of data and enforce synchronization constraints within a component’s network. The specification of software connectors through which context dependent behaviour is correctly propagated remains an open, non trivial issue in their semantics. This paper, building on previous work by the authors, revisits this problem and introduces a model in which context awareness is suitably handled.
TL;DR: This paper concentrates on class diagrams and discusses how a coalgebraic perspective can be of use not only for formalizing their specification, but also as a basis for prototyping.
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.