46 research outputs found
Formal Model Engineering for Embedded Systems Using Real-Time Maude
This paper motivates why Real-Time Maude should be well suited to provide a
formal semantics and formal analysis capabilities to modeling languages for
embedded systems. One can then use the code generation facilities of the tools
for the modeling languages to automatically synthesize Real-Time Maude
verification models from design models, enabling a formal model engineering
process that combines the convenience of modeling using an informal but
intuitive modeling language with formal verification. We give a brief overview
six fairly different modeling formalisms for which Real-Time Maude has provided
the formal semantics and (possibly) formal analysis. These models include
behavioral subsets of the avionics modeling standard AADL, Ptolemy II
discrete-event models, two EMF-based timed model transformation systems, and a
modeling language for handset software.Comment: In Proceedings AMMSE 2011, arXiv:1106.596
A Rewriting-Logic-Based Technique for Modeling Thermal Systems
This paper presents a rewriting-logic-based modeling and analysis technique
for physical systems, with focus on thermal systems. The contributions of this
paper can be summarized as follows: (i) providing a framework for modeling and
executing physical systems, where both the physical components and their
physical interactions are treated as first-class citizens; (ii) showing how
heat transfer problems in thermal systems can be modeled in Real-Time Maude;
(iii) giving the implementation in Real-Time Maude of a basic numerical
technique for executing continuous behaviors in object-oriented hybrid systems;
and (iv) illustrating these techniques with a set of incremental case studies
using realistic physical parameters, with examples of simulation and model
checking analyses.Comment: In Proceedings RTRTS 2010, arXiv:1009.398
Model Checking Classes of Metric LTL Properties of Object-Oriented Real-Time Maude Specifications
This paper presents a transformational approach for model checking two
important classes of metric temporal logic (MTL) properties, namely, bounded
response and minimum separation, for nonhierarchical object-oriented Real-Time
Maude specifications. We prove the correctness of our model checking
algorithms, which terminate under reasonable non-Zeno-ness assumptions when the
reachable state space is finite. These new model checking features have been
integrated into Real-Time Maude, and are used to analyze a network of medical
devices and a 4-way traffic intersection system.Comment: In Proceedings RTRTS 2010, arXiv:1009.398
Verification of Model Transformations to Refactoring Mobile Social Networks
Verification of model processing programs, where only the definitions of the program and the languages of the models to be transformed are analyzed, has become a fundamental issue in model-based software engineering. This analysis may become very complex, but it is performed only once and the results are independent from concrete input models. The formal background of verification methods for graph rewriting-based model transformations has become a subject of research recently. In previous work, we have provided fundamental formal and algorithmic background of a (semi-)automated verification approach for graph transformations. This work concludes these components and put them together to introduce the implementation of a verification system fully integrated into a model transformation framework, VMTS. The strong points of our approach is its usability, its implementation in an existing tool, and its extendibility, which are demonstrated on a case study in the application domain of mobile centric social networks. Our results show that the verification of graph rewriting-based model transformations can be largely automated
Deadlock detection of active objects with synchronous and asynchronous method calls
Open distributed systems are essential in today’s softwaresolutions. However, not all programming paradigms providenatural support for such systems. The setting of concurrentobjects is attractive since it supports independent units ofcomputation. In particular we consider concurrent objectscommunicating by asynchronous method calls supporting non-blocking as well as blocking method calls. In this settingwaiting time can be reduced, allowing efficient cooperationbetween objects. With this concurrency model, deadlock isavoided if blocking calls are avoided. However, blocking callsare sometimes needed to control the order of computation. Thenon-hierarchical nature of concurrent objects systems gives riseto non-trivial deadlock situations. Deadlocks may occur if thereis a call chain with at least one blocking call.We propose amethod for static detection of deadlocks, and demonstrate itsuse on a non-trivial example
Extending the Real-Time Maude Semantics of Ptolemy to Hierarchical DE Models
This paper extends our Real-Time Maude formalization of the semantics of flat
Ptolemy II discrete-event (DE) models to hierarchical models, including modal
models. This is a challenging task that requires combining synchronous
fixed-point computations with hierarchical structure. The synthesis of a
Real-Time Maude verification model from a Ptolemy II DE model, and the formal
verification of the synthesized model in Real-Time Maude, have been integrated
into Ptolemy II, enabling a model-engineering process that combines the
convenience of Ptolemy II DE modeling and simulation with formal verification
in Real-Time Maude.Comment: In Proceedings RTRTS 2010, arXiv:1009.398
Challenges in the specification of full contracts
Partially supported by the Nordunet3 project “COSoDIS”.The complete specification of full contracts - contracts which include tolerated exceptions, and which enable reasoning about the contracts themselves, can be achieved using a combination of temporal and deontic concepts. In this paper we discuss the challenges in combining deontic and other relevant logics, in particular focusing on operators for choice, obligations over sequences, contrary-to-duty obligations, and how internal and external decisions may be incorporated in an action-based language for specifying contracts. We provide different viable interpretations and approaches for the development of such a sound logic and outline challenges for the future.peer-reviewe
Size-Change Termination, Monotonicity Constraints and Ranking Functions
Size-Change Termination (SCT) is a method of proving program termination
based on the impossibility of infinite descent. To this end we may use a
program abstraction in which transitions are described by monotonicity
constraints over (abstract) variables. When only constraints of the form x>y'
and x>=y' are allowed, we have size-change graphs. Both theory and practice are
now more evolved in this restricted framework then in the general framework of
monotonicity constraints. This paper shows that it is possible to extend and
adapt some theory from the domain of size-change graphs to the general case,
thus complementing previous work on monotonicity constraints. In particular, we
present precise decision procedures for termination; and we provide a procedure
to construct explicit global ranking functions from monotonicity constraints in
singly-exponential time, which is better than what has been published so far
even for size-change graphs.Comment: revised version of September 2