958 research outputs found
MTL-Model Checking of One-Clock Parametric Timed Automata is Undecidable
Parametric timed automata extend timed automata (Alur and Dill, 1991) in that
they allow the specification of parametric bounds on the clock values. Since
their introduction in 1993 by Alur, Henzinger, and Vardi, it is known that the
emptiness problem for parametric timed automata with one clock is decidable,
whereas it is undecidable if the automaton uses three or more parametric
clocks. The problem is open for parametric timed automata with two parametric
clocks. Metric temporal logic, MTL for short, is a widely used specification
language for real-time systems. MTL-model checking of timed automata is
decidable, no matter how many clocks are used in the timed automaton. In this
paper, we prove that MTL-model checking for parametric timed automata is
undecidable, even if the automaton uses only one clock and one parameter and is
deterministic.Comment: In Proceedings SynCoP 2014, arXiv:1403.784
Real-time and Probabilistic Temporal Logics: An Overview
Over the last two decades, there has been an extensive study on logical
formalisms for specifying and verifying real-time systems. Temporal logics have
been an important research subject within this direction. Although numerous
logics have been introduced for the formal specification of real-time and
complex systems, an up to date comprehensive analysis of these logics does not
exist in the literature. In this paper we analyse real-time and probabilistic
temporal logics which have been widely used in this field. We extrapolate the
notions of decidability, axiomatizability, expressiveness, model checking, etc.
for each logic analysed. We also provide a comparison of features of the
temporal logics discussed
Non-null Infinitesimal Micro-steps: a Metric Temporal Logic Approach
Many systems include components interacting with each other that evolve with
possibly very different speeds. To deal with this situation many formal models
adopt the abstraction of "zero-time transitions", which do not consume time.
These however have several drawbacks in terms of naturalness and logic
consistency, as a system is modeled to be in different states at the same time.
We propose a novel approach that exploits concepts from non-standard analysis
to introduce a notion of micro- and macro-steps in an extension of the TRIO
metric temporal logic, called X-TRIO. We use X-TRIO to provide a formal
semantics and an automated verification technique to Stateflow-like notations
used in the design of flexible manufacturing systems.Comment: 20 pages, 2 figures, submitted to the conference "FORMATS: Formal
Modelling and Analysis of Timed Systems" 201
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
Modeling Time in Computing: A Taxonomy and a Comparative Survey
The increasing relevance of areas such as real-time and embedded systems,
pervasive computing, hybrid systems control, and biological and social systems
modeling is bringing a growing attention to the temporal aspects of computing,
not only in the computer science domain, but also in more traditional fields of
engineering.
This article surveys various approaches to the formal modeling and analysis
of the temporal features of computer-based systems, with a level of detail that
is suitable also for non-specialists. In doing so, it provides a unifying
framework, rather than just a comprehensive list of formalisms.
The paper first lays out some key dimensions along which the various
formalisms can be evaluated and compared. Then, a significant sample of
formalisms for time modeling in computing are presented and discussed according
to these dimensions. The adopted perspective is, to some extent, historical,
going from "traditional" models and formalisms to more modern ones.Comment: More typos fixe
Temporal Data Modeling and Reasoning for Information Systems
Temporal knowledge representation and reasoning is a major research field in Artificial
Intelligence, in Database Systems, and in Web and Semantic Web research. The ability to
model and process time and calendar data is essential for many applications like appointment
scheduling, planning, Web services, temporal and active database systems, adaptive
Web applications, and mobile computing applications. This article aims at three complementary
goals. First, to provide with a general background in temporal data modeling
and reasoning approaches. Second, to serve as an orientation guide for further specific
reading. Third, to point to new application fields and research perspectives on temporal
knowledge representation and reasoning in the Web and Semantic Web
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