FlexiXML : a portable user interface rendering engine for UsiXML

A considerable amount of effort in software development is dedicated to the user interaction layer.Given the complexity inherent to the development of this layer, it is important to be able to analyse the concepts and ideas being used in the development of a given user interface. This analysis should be performed as early as possible. Model- based user interface development provides a solution to this problem by providing developers with tools that enable both modeling, and reasoning about, user interfaces at different levels of abstraction. Of particular interest here, is the possibility of animating the models to generate actual user interfaces. This paper describes FlexiXML, a tool that performs the rendering and animation of user interfaces described in the UsiXML modeling language

FlexiXML: Um animador de modelos UsiXML

Uma parte considerável do desenvolvimento de software é dedicada à camada de interacção com o utilizador. Face à complexidade inerente ao desenvolvimento desta camada, é importante possibilitar uma análise tão cedo quanto possível dos conceitos e ideias em desenvolvimento para uma dada interface. O desenvolvimento baseado em modelos fornece uma solução para este problema ao facilitar a prototipagem de interfaces a partir dos modelos desenvolvidos. Este artigo descreve uma abordagem à prototipagem de interfaces e apresenta a primeira versão da ferramenta FlexiXML que realiza a interpretação e animação de interfaces descritas em UsiXML

Supporting requirements formulation in software formal verification

Formal verification tools such as model checkers have reached a stage were their applicability in the development process of dependable and safety critical systems has become viable. While the formal verification step in tools such as model checkers is fully automated, writing appropriate models and properties is a skillful process. In particular, a correct understanding of the logics used to express properties is needed to guarantee that properties correctly encode the original requirements. In this paper we illustrate how a patterns-based tool can help in simplifying the process of generating logical formulae from informally expressed requirements

Partial plant models in formal verification of industrial automation discrete systems

The use of a plant model for formal verification of Industrial Automation systems controllers must be used in order to improve the obtained results. However, if there are some cases where the use of a plant model makes the formal verification results more realistic and robust, there are other cases where this does not always happen. The discussion presented in this paper is related with the need of using a Plant Model considering, not all of the Plant Model, but Partial Plant models in order to facilitate formal verification tasks of Industrial Automation Discrete Event Systems

AniMAL - a user interface prototyper and animator for MAL interactor models

Engineering correct software is one of the grand challenges of computer science. Practical design and verification methodologies to ensure correct software can have a substantial impact on how programs are built by the industry. As human-machine systems become more functional, they also become more complex. Consequently, the interactions between the machine and its users becomes less predictable and more difficult to analyse. Using Model Checking it is possible to automatically analyse the behaviour of a modelled system. Hence, different authors have investigated the applicability of model checking to the analysis of human-machine interactions. The IVY workbench is a tool that supports system design and verification, by providing a model checking based integrated modelling and analysis environment. The tool is based around a plugin architecture, and although it features a verification results' analyser, it thus far lacked the ability to visually expose the sequence of events that lead to a system failure on a system's prototype. We propose the AniMAL plugin as an extension to the IVY workbench, providing automatic user interface prototyping and verification results' animation, while allowing thorough customisation

Topological insulator particles as optically induced oscillators: towards dynamical force measurements and optical rheology

We report the first experimental study upon the optical trapping and manipulation of topological insulator (TI) particles. By virtue of the unique TI properties, which have a conducting surface and an insulating bulk, the particles present a peculiar behaviour in the presence of a single laser beam optical tweezers: they oscillate in a plane perpendicular to the direction of the laser propagation, as a result of the competition between radiation pressure and gradient forces. In other words, TI particles behave as optically induced oscillators, allowing dynamical measurements with unprecedented simplicity and purely optical control. Actually, optical rheology of soft matter interfaces and biological membranes, as well as dynamical force measurements in macromolecules and biopolymers, may be quoted as feasible possibilities for the near future.Comment: 6 pages, 5 figures. Correspondence and requests for Supplementary Material should be addressed to [email protected]

Simulation and formal verification of industrial systems controllers

Actually, the safety control is one of the most important aspects studied by the international researchers, in the field of design and development of automated production systems due to social (avoid work accidents, ...), economics (machine stop time reduction, increase of productivity,...) and technological aspects (less risks of damage of the components,...). Some researchers of the Engineering School of University of Minho are also studying these aspects of safety control, using simulation and modelchecking techniques in the development of Programmable Logic Controllers (PLC) programs. The techniques currently used for the guarantee of automated production systems control safety are the Simulation and the Formal Verification. If the Simulation is faster to execute, has the limitation of considering only some system behavior evolution scenarios. Using Formal Verification it exists the advantage of testing all the possible system behavior evolution scenarios but, sometimes, it exists the limitation of the time necessary for the attainment of formal verification results. In this paper it is shown, as it is possible, and desirable, to conciliate these two techniques in the analysis of PLC programs. With the simultaneous use of these two techniques, the developed PLC programs are more robust and not subject to errors. It is desirable the use of simulation before using formal verification in the analysis of a system control program because with the simulation of some possible system behaviors it is possible to eliminate a set of program errors in reduced intervals of time and that would not happen if these errors were detected only through the use of formal verification techniques. Conciliating these two techniques it can be substantially reduced the time necessary for the attainment of results through the use of the formal verification technique. For the analysis of a system control program for simulation and formal verification it is used the Dymola for the Simulation (through the creation of system models with Modelica language) and UPPAAL (through the creation of system models with timed automata)

Abordagem sistemática para o controlo seguro de sistemas aeroespaciais

A verificação formal do comportamento de sistemas tempo-real é uma tarefa complexa, por várias razões. Há múltiplos trabalhos desenvolvidos na área de verificação formal, por model-checking de sistemas tempo-real, sendo que diversos softwares foram desenvolvidos para o efeito. Um dos problemas mais complexos para serem resolvidos na análise de controladores tempo-real é a conversão das linguagens de programação dos controladores nas linguagens formais, por exemplo autómatos finitos temporizados para depois poderem ser verificados formalmente através dos model-checkers existentes. Se a metodologia de elaboração dos programas for bem desenvolvida e conhecida, essa tarefa pode ser muito facilitada. Por outro lado, grande parte dos sistemas tempo-real (principalmente os sistemas embebidos que pretendemos estudar) é programado em linguagem C. Neste artigo pretende-se estabelecer uma metodologia de criação de programas em código C, a partir do formalismo de especificação SFC, tendo em conta a verificação formal de propriedades comportamentais desejadas para o sistema, utilizando a técnica Model- Checking e o model-checker UPPAAL. Estes estudos preliminares são efectuados no contexto de colaboração entre Investigadores dos centros de investigação CT2M, ALGORITMI e CCTC da Universidade do Minho (Portugal) e do Departamento de Engenharia Mecânica do Instituto Tecnológico de Aeronáutica (Brasil).Formal verification of real-time systems behavior of is a complex task, for several reasons. There are multiple works developed in the domain of formal verification of real-time system behavior by model-checking, and various software tools were developed for this purpose. One of the most complexes problems to be solved in the analysis of real-time controllers is the conversion of programming languages controllers in formal languages, for example finite timed automata to be used as inputs of the existing model-checkers. If the methodology of the programming is well developed and known, this task can be greatly facilitated. Moreover, most real-time systems (especially embedded systems that we intend to study) are programmed in C language This article seeks to establish the methodology of creating programs in C code, from SFC specification formalism, taking into account the formal verification of behavior al properties desired for the system, using the Model-Checking technique and the modelchecker UPPAAL. A case study is presented to illustrate the methodology presented. These preliminary studies are presented on the context of a research collaboration project being developed by researchers of CT2M, ALGORITMI and CCTC research centers of University of Minho (Portugal) and the Mechanical Engineering Department of Technological Institute of Aeronautics (Brazil)