1,720,998 research outputs found
An Abstract Module Concept for Graph Transformation Systems
Full text linkGraph transformation systems are a well known formal specification technique that support the rule based specification of the dynamic behaviour of systems. Recently, many specification languages for graph transformation systems have been developed, and modularization techniques are then needed in order to deal with large and complex graph transformation specifications, to enhance the reuse of specifications, and to hide implementation details. In this paper we present an abstract categorical approach to modularization of graph transformation systems. Modules are called cat–modules and defined over a generic category cat of graph transformation specifications and morphisms. We describe the main characteristics and properties of cat–modules, their interconnection operations, namely union, composition and refinement of modules, and some compatibility properties between such operations
Cooperating Graph Grammar Systems
No full textIn this paper the concept of cooperation is introduced into the context of graph grammars. Beside the definition of cooperating graph rewriting systems and beside some general comparisons between generated languages, the NLC and BNLC cooperating graph rewriting systems are studied in detail.
As a mean for expressing the synergy deriving from the cooperation, a
particular graph grammar, called system grammar, is defined and used
in NLC and BNLC context
3D Molecules Visualization with XRmol: An AR Web Tool for Mobile Devices
No full textWe present XRmol, a prototype web application, based on the WebXR standard, for visualizing 3D proteins and nucleic acids. The work represents a contribution to the investigation of the potential stemming from the AR paradigm coupled with the use of personal smartphones and features a number of solutions for improving access, portability, and use in different contexts. A first pilot study with 14 volunteers outlines its potential for integration into daily lab activities and use in educational contexts
Deriving Performance Models from Software Architecture Specifications
No full textQuantitative analysis of software systems has been recognized to be important and useful for requirements and design, and, specifically, performance analysis should be integrated in the software development life cycle from the early stages. To this aim, several approaches have been recently proposed to integrate or combine performance analysis and software architecture specification. In this paper we present a brief review and a comparison of some approaches that derive performance models from SA specification. We focus on the generality of the proposed methodologies, the required constraints and assumptions, the type of performance model, the separation of performance model and specification language, the implementation, and how easily the obtained performance results can provide a feedback to the software designer
On a Uniform Representation of Transformation Systems
No full textWe discuss an intermediate language to represent transitions defining behaviours of autonomous agents. The language allows a uniform representation of several diagrammatic languages for specification of reactive systems, based on an underlying notion of transition. The translation of graph transformations to this language opens an opportunity for a notion of communication between agents represented by graphs
On Relationships Between Stochastic Process Algebras with Æmilia and Queueing Network Models
No full textVarious models and methods have been proposed and
applied for quantitative system performance evaluation, including
Queueing Networks (QN) and Stochastic extensions
of Process Algebras (SPA), that show different characteristics
and advantages. These formalisms have been applied to
model and analyze the performance of hardware and software
systems at different levels of abstraction, and more recently
at the Software Architectures level. In this paper we
investigate some relationships between SPA and QN, and
more specifically we compare the SPA specifications based
on Æmilia and a class of QN. We propose an approach
to translate a QN model into an Æmilia specification in
order to take advantage of the model definition based on
SPA that allows the combination of functional and performance
analysis and compositional, graphical and hierarchical
modeling of complex systems. This work extends and
reverses a previous comparison of the two formalisms based
on the mapping from Æmilia specifications to QN. The integration
of these two formalisms aims to combine their main
advantages as tools for system performance analysis, in order
to efficiently describe and analyze both functional and
performance properties of system specifications within the
same integrated framework
Integrating performance modeling in the software development process
No full textWe discuss the integration of performance modeling and analysis in the software development process. Various approaches have been recently defined to integrate performance models and specification languages and models to derive or validate non-functional properties of a software system. Such integration of quantitative performance analysis should provide feedback easily understandable by the software designer and system developers. A framework that allows the combination of different performance modeling techniques and methods, defined at different levels of abstraction, should better support performance analysis and validation of complex and heterogeneous software systems during the software development process
Petri nets for modelling and analysing trophic networks
Full text linkWe consider trophic networks, a kind of networks used in ecology to represent feeding interactions (what-eats-what) in an ecosys- tem. We observe that trophic networks can be naturally modelled as Petri nets and this suggests the possibility of exploiting Petri nets for the analysis and simulation of trophic networks. Some preliminary steps in this directions and some ideas for future development are presented
Refinements of Graph Transformation Systems via Rule Expressions
No full textGraph transformation systems are formal models of computational systems, specified by rules that describe the atomic steps of the system. A refinement of a graph transformation system is given by associating with each of its rules a composition of rules of a refining system, that has the same visible effect as the original rule. The basic composition operations on graph transformation rules are sequential and parallel composition, corresponding to temporal and spatial refinements respectively. Syntactically refinements are represented by rule expressions that describe how the refining rules shall be composed
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