Methodologies for self-organising systems:a SPEM approach

We define ’SPEM fragments’ of five methods for developing self-organising multi-agent systems. Self-organising traffic lights controllers provide an application scenario

Incremental UML for Agile development: embedding UML class models in source code

Agile methods favor "working software over comprehensive documentation." The latter presumably includes Unified Modeling Language. UML is expensive to maintain, and it lacks good drill-down mechanisms, however, UML affords very useful visualizations. This paper describes a discipline for incrementally embedding graphical UML class models within source code for continuous agile development. The approach consists of identifying a main function, and having it drive the piece-wise creation of UML by explicitly including in its postconditions the placement of functions corresponding directly to requirements. The approach thus introduces higher order pre-and postconditions. A specific process is provided for carrying this out, together with examples. It enables UML class model visualization in rapid development, especially when tool-supported

Formalization and Validation of Safety-Critical Requirements

The validation of requirements is a fundamental step in the development process of safety-critical systems. In safety critical applications such as aerospace, avionics and railways, the use of formal methods is of paramount importance both for requirements and for design validation. Nevertheless, while for the verification of the design, many formal techniques have been conceived and applied, the research on formal methods for requirements validation is not yet mature. The main obstacles are that, on the one hand, the correctness of requirements is not formally defined; on the other hand that the formalization and the validation of the requirements usually demands a strong involvement of domain experts. We report on a methodology and a series of techniques that we developed for the formalization and validation of high-level requirements for safety-critical applications. The main ingredients are a very expressive formal language and automatic satisfiability procedures. The language combines first-order, temporal, and hybrid logic. The satisfiability procedures are based on model checking and satisfiability modulo theory. We applied this technology within an industrial project to the validation of railways requirements

Applying MDE tools to defining domain specific languages for model management

In the model driven engineering (MDE), modeling languages play a central role. They range from the most generic languages such as UML, to more individual ones, called domain-specific modeling languages (DSML). These languages are used to create and manage models and must accompany them throughout their life cycle and evolution. In this paper we propose a domain-specific language for model management, to facilitate the user's task, developed with techniques and tools used in the MDE paradigm.Fil: Pérez, Gabriela. Universidad Nacional de la Plata. Facultad de Informática. Laboratorio de Investigación y Formación en Informática Avanzada; ArgentinaFil: Irazábal, Jerónimo. Universidad Nacional de la Plata. Facultad de Informática. Laboratorio de Investigación y Formación en Informática Avanzada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pons, Claudia Fabiana. Universidad Nacional de la Plata. Facultad de Informática. Laboratorio de Investigación y Formación en Informática Avanzada; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Giandini, Roxana Silvia. Universidad Nacional de la Plata. Facultad de Informática. Laboratorio de Investigación y Formación en Informática Avanzada; Argentin

Reactive molecular dynamics simulations of organometallic compound W(CO)6 fragmentation

Irradiation- and collision-induced fragmentation studies provide information about geometry, electronic properties and interactions between structural units of various molecular systems. Such knowledge brings insights into irradiation-driven chemistry of molecular systems which is exploited in different technological applications. An accurate atomistic-level simulation of irradiation-driven chemistry requires reliable models of molecular fragmentation which can be verified against mass spectrometry experiments. In this work fragmentation of a tungsten hexacarbonyl, W(CO)$_6$, molecule is studied by means of reactive molecular dynamics simulations. The quantitatively correct fragmentation picture including different fragmentation channels is reproduced. We show that distribution of the deposited energy over all degrees of freedom of the parent molecule leads to thermal evaporation of CO groups and the formation of W(CO)$_n^+$ ($n = 0-5$) fragments. Another type of fragments, WC(CO)$_n^+$ ($n = 0-4$), is produced due to cleavage of a C--O bond as a result of the localized energy deposition. Calculated fragment appearance energies are in good agreement with experimental data. These fragmentation mechanisms have a general physical nature and should take place in radiation-induced fragmentation of different molecular and biomolecular systems.Comment: 11 pages, 6 figures, submitted to European Physical Journal

An ontological approach for recovering legacy business content

Legacy Information Systems (LIS) pose a challenge for many organizations. On one hand, LIS are viewed as aging systems needing replacement; on the other hand, years of accumulated business knowledge have made these systems mission-critical. Current approaches however are often criticized for being overtly dependent on technology and ignoring the business knowledge which resides within LIS. In this light, this paper proposes a means of capturing the business knowledge in a technology agnostic manner and transforming it in a way that reaps the benefits of clear semantic expression - this transformation is achieved via the careful use of ontology. The approach called Content Sophistication (CS) aims to provide a model of the business that more closely adheres to the semantics and relationships of objects existing in the real world. The approach is illustrated via an example taken from a case study concerning the renovation of a large financial system and the outcome of the approach results in technology agnostic models that show improvements along several dimensions