1,411 research outputs found

    An NMF solution for the Petri Nets to State Charts case study at the TTC 2013

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    Software systems are getting more and more complex. Model-driven engineering (MDE) offers ways to handle such increased complexity by lifting development to a higher level of abstraction. A key part in MDE are transformations that transform any given model into another. These transformations are used to generate all kinds of software artifacts from models. However, there is little consensus about the transformation tools. Thus, the Transformation Tool Contest (TTC) 2013 aims to compare different transformation engines. This is achieved through three different cases that have to be tackled. One of these cases is the Petri Net to State Chart case. A solution has to transform a Petri Net to a State Chart and has to derive a hierarchical structure within the State Chart. This paper presents the solution for this case using NMF Transformations as transformation engine.Comment: In Proceedings TTC 2013, arXiv:1311.7536. arXiv admin note: substantial text overlap with arXiv:1312.034

    An NMF solution for the Flowgraphs case at the TTC 2013

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    Software systems are getting more and more complex. Model-driven engineering (MDE) offers ways to handle such increased complexity by lifting development to a higher level of abstraction. A key part in MDE are transformations that transform any given model into another. These transformations are used to generate all kinds of software artifacts from models. However, there is little consensus about the transformation tools. Thus, the Transformation Tool Contest (TTC) 2013 aims to compare different transformation engines. This is achieved through three different cases that have to be tackled. One of these cases is the Flowgraphs case. A solution has to transform a Java code model into a simplified version and has to derive control and data flow. This paper presents the solution for this case using NMF Transformations as transformation engine.Comment: In Proceedings TTC 2013, arXiv:1311.753

    View-based textual modelling

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    This work introduces the FURCAS approach, a framework for view-based textual modelling. FURCAS includes means that allow software language engineers to define partial and overlapping textual modelling languages. Furthermore, FURCAS provides an incremental update approach that enables modellers to work with multiple views on the same underlying model. The approach is validated against a set of formal requirements, as well as several industrial case studies showing its practical applicability

    Using an OCL Impact Analysis Algorithm for View-Based Textual Modelling

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    The Object Constraint Language (OCL) has become a vital part of many frameworks, tools and languages within model-driven engineering. One such application of OCL is the use for describing rules in concrete syntax definitions. Within the textual modeling framework FURCAS, OCL is extensively used for the definition of lookup and attribution rules. Based on these rules the model which is described by such a textual representation is created and updated accordingly. Changes on models over which such an expression is specified require the expression to be re-evaluated to keep the constructed model up-to-date. However, the effort for re-evaluating OCL expressions over a set of model elements grows with the  number of elements, the complexity of the expressions, and the number of model changes. Thus, having large models and/or complex expressions places considerable performance costs on OCL evaluation. Techniques to reduce this effort have been presented in previous work but do not cover the full range of OCL expressions, in particular calls to operations defined in OCL, including recursive operations. In this paper, we present an approach that is applicable to the full range of OCL expressions. We validated our approach based on a large set of models and complex expressions to evaluate the performance impact of our newly introduced techniques

    Carburisation of ferritic Fe–Cr alloys by low carbon activity gases

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    Model Fe–Cr alloys were exposed to Ar–CO2–H2O gas mixtures at 650 and 800 °C. At equilibrium, these atmospheres are oxidising to the alloys, but decarburising (aC ≈ 10−15 to 10−13). In addition to developing external oxide scales, however, the alloys also carburised. Carbon supersaturation at the scale/alloy interface relative to the gas reflects local equilibrium: a low oxygen potential corresponds to a high pCO/pCO2 ratio, and hence to a high carbon activity. Interfacial carbon activities calculated on the basis of scale–alloy equilibrium are shown to be in good agreement with measured carburisation rates and precipitate volume fractions, providing support for the validity of the thermodynamic model

    4th Workshop on View-Based, Aspect-Oriented and Orthographic Software Modelling : Proceedings, 2 March 2016, Karlsruhe, Germany

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    Modern software engineering paradigms, such as model-driven development, multi-view modelling, or role-based software development, use different types and combinations of abstraction techniques to decompose systems into human-tractable pieces. This leads to an increasing number of models and views that have to be considered, which presents fundamental challenges for engineers of complex softwareintensive systems. Software developers need technologies for operationally managing views of systems in a consistent way, and software architects require concepts that indicate in which way views and models should be developed, evolved, and navigated as projects evolve. The goal of this workshop is to distil a common understanding of existing approaches and current research directions in treating heterogeneous models of software and systems

    Industrial Implementation of a Documentation Framework for Architectural Decisions

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    Architecture decisions are often not explicitly documented in practice but reside in the architect's mind as tacit knowledge, even though explicit capturing and documentation of architecture decisions has been associated with a multitude of benefits. As part of a research collaboration with ABB, we developed a tool to document architecture decisions. This tool is an add-in for Enterprise Architect and is an implementation of a viewpoint-based decision documentation framework. To validate the add-in, we conducted an exploratory case study with ABB architects. In the study, we assessed the status quo of architecture decision documentation, identified architects' expectations of the ideal decision documentation tool, and evaluated the new add-in. We found that although awareness of decision documentation is increasing at ABB, several barriers exist that limit the use of decisions in practice. Regarding their ideal tool, architects want a descriptive and efficient approach. Supplemental features like reporting or decision sharing are requested. The new add-in, was well-perceived by the architects. As a result of the study, we propose a clearer separation of problem, outcomes, and alternatives for the decision documentation framework

    Entanglement of charge transfer, hole doping, exchange interaction and octahedron tilting angle and their influence on the conductivity of La1-xSrxFe0.75Ni0.25O3-{\delta}: A combination of x-ray spectroscopy and diffraction

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    Substitution of La by Sr in the 25% Ni doped charge transfer insulator LaFeO3 creates structural changes that inflect the electrical conductivity caused by small polaron hopping via exchange interactions and charge transfer. The substitution forms electron holes and a structural crossover from orthorhombic to rhombohedral symmetry, and then to cubic symmetry. The structural crossover is accompanied by a crossover from Fe3+-O2--Fe3+ superexchange interaction to Fe3+-O2--Fe4+ double exchange interaction, as evidenced by a considerable increase of conductivity. These interactions and charge transfer mechanism depend on superexchange angle, which approaches 180{\deg} upon increasing Sr concentration, leading an increased overlap between the O (2p) and Fe/Ni (3d) orbitals

    Melanocortin-4 receptor gene: case-control study and transmission disequilibrium test confirm that functionally relevant mutations are compatible with a major gene effect for extreme obesity

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    We initially performed a mutation screen of the coding region of the MC4R in 808 extremely obese children and adolescents and 327 underweight or normal-weight controls allowing for a case-control study. A total of 16 different missense, nonsense, and frameshift mutations were found in the obese study group; five of these have not been observed previously. In vitro assays revealed that nine [the haplotype (Y35X; D37V) was counted as one mutation] of the 16 mutations led to impaired cAMP responses, compared with wild-type receptor constructs. In contrast, only one novel missense mutation was detected in the controls, which did not alter receptor function. The association test based on functionally relevant mutations was positive (P = 0.006, Fisher's exact test, one-sided). We proceeded by screening a total of 1040 parents of 520 of the aforementioned obese young index patients to perform transmission disequilibrium tests. The 11 parental carriers of functionally relevant mutations transmitted the mutation in 81.8% (P = 0.033; exact one-sided McNemar test). These results support the hypothesis that these MC4R mutations represent major gene effects for obesity
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