Automated Model Synchronization: A Case Study on UML with Maude

Design specifications of software-intensive systems involve models that have been defined with different modelling languages for different purposes. Hence, a specification can be seen as the description of a system from multiple viewpoints, each providing domain-specific constructs for modelling the system in a more precise way. Such heterogeneity of models can jeopardize the consistency of the specification, because updates in one viewpoint may cause unpredictable design errors in other viewpoints, which can then be transferred to the implementation. OMG’s Meta-Object Facility enhances the automation of the model consistency management by providing a uniform format for different modelling languages. In this paper, we illustrate a technique, based on rewriting logic and on strategies for finding inconsistencies in MOF-based heterogeneous specifications and for resolving them in an automated way

Checking bisimilarity for attributed graph transformation

Borrowed context graph transformation is a technique developed by Ehrig and Koenig to define bisimilarity congruences from reduction semantics defined by graph transformation. This means that, for instance, this technique can be used for defining bisimilarity congruences for process calculi whose operational semantics can be defined by graph transformation. Moreover, given a set of graph transformation rules, the technique can be used for checking bisimilarity of two given graphs. Unfortunately, we can not use this ideas to check if attributed graphs are bisimilar, i.e. graphs whose nodes or edges are labelled with values from some given data algebra and where graph transformation involves computation on that algebra. The problem is that, in the case of attributed graphs, borrowed context transformation may be infinitely branching. In this paper, based on borrowed context transformation of what we call symbolic graphs, we present a sound and relatively complete inference system for checking bisimilarity of attributed graphs. In particular, this means that, if using our inference system we are able to prove that two graphs are bisimilar then they are indeed bisimilar. Conversely, two graphs are not bisimilar if and only if we can find a proof saying so, provided that we are able to prove some formulas over the given data algebra. Moreover, since the proof system is complex to use, we also present a tableau method based on the inference system that is also sound and relatively complete.Postprint (published version

Formal Model Merging Applied to Class Diagram Integration

AbstractThe integration of software artifacts is present in many scenarios of the Software Engineering field: object-oriented modeling, relational databases, XML schemas, ontologies, aspect-oriented programming, etc. In Model Management, software artifacts are viewed as models that can be manipulated by means of generic operators, which are specified independently of the context in which they are used. One of these operators is Merge, which enables the automated integration of models. Solutions for merging models that are achieved by applying this operator are more abstract and reusable than the ad-hoc solutions that are pervasive in many contexts of the Software Engineering field. In this paper, we present our automated approach for generic model merging from a practical standpoint, providing support for conflict resolution and traceability between software artifacts by using the QVT Relations language. We focus on the definition of our operator Merge, applying it to Class Diagrams integration

High-Momentum Response of Liquid 3He

A final-state-effects formalism suitable to analyze the high-momentum response of Fermi liquids is presented and used to study the dynamic structure function of liquid 3He. The theory, developed as a natural extension of the Gersch-Rodriguez formalism, incorporates the Fermi statistics explicitly through a new additive term which depends on the semidiagonal two-body density matrix. The use of a realistic momentum distribution, calculated using the diffusion Monte Carlo method, and the inclusion of this additive correction allows for good agreement with available deep-inelastic neutron scattering data

Domain-specific discrete event modelling and simulation using graph transformation

The final publication is available at Springer via http://dx.doi.org/10.1007/s10270-012-0242-3Graph transformation is being increasingly used to express the semantics of domain-specific visual languages since its graphical nature makes rules intuitive. However, many application domains require an explicit handling of time to accurately represent the behaviour of a real system and to obtain useful simulation metrics to measure throughputs, utilization times and average delays. Inspired by the vast knowledge and experience accumulated by the discrete event simulation community, we propose a novel way of adding explicit time to graph transformation rules. In particular, we take the event scheduling discrete simulation world view and provide rules with the ability to schedule the occurrence of other rules in the future. Hence, our work combines standard, efficient techniques for discrete event simulation (based on the handling of a future event set) and the intuitive, visual nature of graph transformation. Moreover, we show how our formalism can be used to give semantics to other timed approaches and provide an implementation on top of the rewriting logic system Maude.Work partially sponsored by the Spanish Ministry, under project “Go Lite” (TIN2011-24139) as well as by the R&D programme of the Community of Madrid, project “e-Madrid” (S2009/TIC-1650). We are grateful to the anonymous reviewers, which helped in improving previous versions of the paper

Repotting the Geraniums: On Nested Graph Transformation Rules

We propose a scheme for rule amalgamation based on nested graph predicates. Essentially, we extend all the graphs in such a predicate with right hand sides. Whenever such an enriched nested predicate matches (i.e., is satisfied by) a given host graph, this results in many individual match morphisms, and thus many “small” rule applications. The total effect is described by the amalgamated rule. This makes for a smooth, uniform and very powerful amalgamation scheme, which we demonstrate on a number of examples. Among the examples is the following, which we believe to be inexpressible in very few other parallel rule formalism proposed in the literature: repot all flowering geraniums whose pots have cracked.\u

Distinguibility, degeneracy, and correlations in three harmonically trapped bosons in one dimension

We study a system of two bosons of one species and a third atom of a second species in a one-dimensional parabolic trap at zero temperature. We assume contact repulsive inter- and intraspecies interactions. By means of an exact diagonalization method we calculate the ground and excited states for the whole range of interactions. We use discrete group theory to classify the eigenstates according to the symmetry of the interaction potential. We also propose and validate analytical Ansätze gaining physical insight over the numerically obtained wave functions. We show that, for both approaches, it is crucial to take into account that the distinguishability of the third atom implies the absence of any restriction over the wave function when interchanging this boson with any of the other two. We find that there are degeneracies in the spectra in some limiting regimes, that is, when the interspecies and/or the intraspecies interactions tend to infinity. This is in contrast with the three-identical boson system, where no degeneracy occurs in these limits. We show that, when tuning both types of interactions through a protocol that keeps them equal while they are increased towards infinity, the systems's ground state resembles that of three indistinguishable bosons. Contrarily, the systems's ground state is different from that of three-identical bosons when both types of interactions are increased towards infinity through protocols that do not restrict them to be equal. We study the coherence and correlations of the system as the interactions are tuned through different protocols, which permit us to build up different correlations in the system and lead to different spatial distributions of the three atoms

Acções educativas para favorecer o valor responsabilidade nos alunos da 9ª classe do complexo escolar nº 187-lubango-huíla.(Original)

This article intends to present the results of the study carried aut at School Compex No. 187, Lubango-Huila and aims to develop educational actions for the formation of the value responsability in students. This research starts from the need to improve students behavior in Physical Education classroom and at the same time promote discipline in other matters that are not practical within the school. The result will be a tool that the Physical Education  professional can use in their classes and in this way support the work in values education that is carried aut by all the teachers in the school whith family and development involvement of the students in society in general.O presente artigo tem a intenção de apresentar os resultados do estudo feito no Complexo Escolar nº187 Lubango-Huíla e tem como objectivo: elaborar acções educativas para a formação do valor responsabilidade nos alunos. Esta investigação parte da necessidade de melhorar o comportamento dos estudantes nas aulas de Educação Física e ao mesmo tempo favorecer a disciplina nos demais assuntos que não são práticos dentro da escola. O resultado será una ferramenta que o profissional da Educação Física pode utilizar nas suas aulas e desta maneira suportar o trabalho na educação em valores que realiza-se por parte de todos os docentes na escola com incidência na família e no desenvolvimento do aluno na sociedade em geral

Tracing Properties of UML and OCL Models with Maude

The starting point of this paper is a system described in form of a UML class diagram where system states are characterized by OCL invariants and system transitions are defined by OCL pre- and postconditions. The aim of our approach is to assist the developer in learning about the consequences of the described system states and transitions and about the formal implications of the properties that are explicitly given. We propose to draw conclusions about the stated constraints by translating the UML and OCL model into the algebraic specification language and system Maude, which is based on rewrite logic. We will concentrate in this paper on employing Maude's capabilities for state search. Maude's state search offers the possibility to describe a start configuration of the system and then explore all configurations reachable by rewriting. The search can be adjusted by formulating requirements for the allowed states and the allowed transitions.Comment: In Proceedings AMMSE 2011, arXiv:1106.596