226 research outputs found
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
Formal Visual Modeling of Real-Time Systems in e-Motions: Two Case Studies
e-Motions is an Eclipse-based visual timed model transformation framework
with a Real-Time Maude semantics that supports the usual Maude formal analysis
methods, including simulation, reachability analysis, and LTL model checking.
e-Motions is characterized by a novel and powerful set of constructs for
expressing timed behaviors. In this paper we illustrate the use of these
constructs --- and thereby implicitly investigate their suitability to define
real-time systems in an intuitive way --- to define and formally analyze two
prototypical and very different real-time systems: (i) a simple round trip time
protocol for computing the time it takes a message to travel from one node to
another, and back; and (ii) the EDF scheduling algorithm.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
Rewriting Modulo SMT
Combining symbolic techniques such as: (i) SMT solving, (ii) rewriting modulo theories, and (iii) model checking can enable the analysis of infinite-state systems outside the scope of each such technique. This paper proposes rewriting modulo SMT as a new technique combining the powers of (i)-(iii) and ideally suited to model and analyze infinite-state open systems; that is, systems that interact with a non-deterministic environment. Such systems exhibit both internal non-determinism due to the system, and external non-determinism due to the environment. They are not amenable to finite-state model checking analysis because they typically are infinite-state. By being reducible to standard rewriting using reflective techniques, rewriting modulo SMT can both naturally model and analyze open systems without requiring any changes to rewriting-based reachability analysis techniques for closed systems. This is illustrated by the analysis of a real-time system beyond the scope of timed automata methods
Rewriting Modulo SMT and Open System Analysis
This paper proposes rewriting modulo SMT, a new technique that
combines the power of SMT solving, rewriting modulo theories, and model checking.
Rewriting modulo SMT is ideally suited to model and analyze reachability
properties of infinite-state open systems, i.e., systems that interact with a nondeterministic
environment. Such systems exhibit both internal nondeterminism,
which is proper to the system, and external nondeterminism, which is due to the
environment. In a reflective formalism, such as rewriting logic, rewriting modulo
SMT can be reduced to standard rewriting. Hence, rewriting modulo SMT naturally
extends rewriting-based reachability analysis techniques, which are available
for closed systems, to open systems. The proposed technique is illustrated
with the formal analysis of: (i) a real-time system that is beyond the scope of
timed-automata methods and (ii) automatic detection of reachability violations in
a synchronous language developed to support autonomous spacecraft operations.NSF Grant CNS 13-19109 and NASA Research Cooperative Agreement No. NNL09AA00AOpe
Capacity sharing and stealing in serverbased real-time systems
A dynamic scheduler that supports the coexistence of guaranteed and non-guaranteed bandwidth servers is proposed.
Overloads are handled by an efficient reclaiming of residual capacities originated by early completions as well as by allowing
reserved capacity stealing of non-guaranteed bandwidth servers. The proposed dynamic budget accounting mechanism
ensures that at a particular time the currently executing server is using a residual capacity, its own capacity or is stealing
some reserved capacity, eliminating the need of additional server states or unbounded queues. The server to which the
budget accounting is going to be performed is dynamically determined at the time instant when a capacity is needed. This
paper describes and evaluates the proposed scheduling algorithm, showing that it can efficiently reduce the mean tardiness
of periodic jobs. The achieved results become even more significant when tasks’ computation times have a large variance
Twenty years of rewriting logic
AbstractRewriting logic is a simple computational logic that can naturally express both concurrent computation and logical deduction with great generality. This paper provides a gentle, intuitive introduction to its main ideas, as well as a survey of the work that many researchers have carried out over the last twenty years in advancing: (i) its foundations; (ii) its semantic framework and logical framework uses; (iii) its language implementations and its formal tools; and (iv) its many applications to automated deduction, software and hardware specification and verification, security, real-time and cyber-physical systems, probabilistic systems, bioinformatics and chemical systems
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