1,708 research outputs found
Petri nets for systems and synthetic biology
We give a description of a Petri net-based framework for
modelling and analysing biochemical pathways, which uni¯es the qualita-
tive, stochastic and continuous paradigms. Each perspective adds its con-
tribution to the understanding of the system, thus the three approaches
do not compete, but complement each other. We illustrate our approach
by applying it to an extended model of the three stage cascade, which
forms the core of the ERK signal transduction pathway. Consequently
our focus is on transient behaviour analysis. We demonstrate how quali-
tative descriptions are abstractions over stochastic or continuous descrip-
tions, and show that the stochastic and continuous models approximate
each other. Although our framework is based on Petri nets, it can be
applied more widely to other formalisms which are used to model and
analyse biochemical networks
Formalization and Correctness of the PALS Architectural Pattern for Distributed Real-Time Systems
Many Distributed Real-Time Systems (DRTS), such as integrated modular avionics systems and distributed control systems in
motor vehicles, are made up of a collection of components communicating asynchronously among themselves and with their environment
that must change their state and respond to environment inputs within
hard real-time bounds. Such systems are often safety-critical and need
to be certi???ed; but their certi???cation is currently very hard due to their
distributed nature. The Physically Asynchronous Logically Synchronous
(PALS) architectural pattern can greatly reduce the design and veri???cation complexities of achieving virtual synchrony in a DTRS. This work
presents a formal speci???cation of PALS as a formal model transformation that maps a synchronous design, together with a set of performance
bounds of the underlying infrastructure, to a formal DRTS speci???cation
that is semantically equivalent to the synchronous design. This semantic
equivalence is proved, showing that the formal veri???cation of temporal
logic properties of the DRTS can be reduced to their veri???cation on the
much simpler synchronous design. An avionics system case study is used
to illustrate the usefulness of PALS for formal verification purposes.unpublishednot peer reviewe
Events in Property Patterns
A pattern-based approach to the presentation, codification and reuse of
property specifications for finite-state verification was proposed by Dwyer and
his collegues. The patterns enable non-experts to read and write formal
specifications for realistic systems and facilitate easy conversion of
specifications between formalisms, such as LTL, CTL, QRE. In this paper, we
extend the pattern system with events - changes of values of variables in the
context of LTL.Comment: 14 pages, 3 figure
Trace checking of Metric Temporal Logic with Aggregating Modalities using MapReduce
Modern complex software systems produce a large amount of execution data,
often stored in logs. These logs can be analyzed using trace checking
techniques to check whether the system complies with its requirements
specifications. Often these specifications express quantitative properties of
the system, which include timing constraints as well as higher-level
constraints on the occurrences of significant events, expressed using aggregate
operators. In this paper we present an algorithm that exploits the MapReduce
programming model to check specifications expressed in a metric temporal logic
with aggregating modalities, over large execution traces. The algorithm
exploits the structure of the formula to parallelize the evaluation, with a
significant gain in time. We report on the assessment of the implementation -
based on the Hadoop framework - of the proposed algorithm and comment on its
scalability.Comment: 16 pages, 6 figures, Extended version of the SEFM 2014 pape
10031 Abstracts Collection -- Quantitative Models: Expressiveness and Analysis
From Jan 18 to Jan 22, 2010, the Dagstuhl Seminar 10031 ``Quantitative Models: Expressiveness and Analysis \u27\u27 was held in Schloss Dagstuhl~--~Leibniz Center for Informatics. During the seminar, several participants presented their current
research, and ongoing work and open problems were discussed. Abstracts of
the presentations given during the seminar as well as abstracts of
seminar results and ideas are put together in this paper. The first section
describes the seminar topics and goals in general.
Links to extended abstracts or full papers are provided, if available
Workflow completion patterns
The most common correctness requirement for a (business) workflow is the completion requirement, imposing that, in some form, every case-instance of the workflow reaches its final state. In this paper, we define three workflow completion patterns, called the mandatory, optional and possible completion. These patterns are formalized in terms of the temporal logic CTL*, to remove ambiguities, allow for easy comparison, and have direct applicability. In contrast to the existing methods, we do not look at the control flow in isolation but include some data information as well. In this way the analysis remains tractable but gains precision. Together with our previous work on data-flow (anti-)patterns, this paper is a significant step towards a unifying framework for complete workflow verification, using the well-developed, stable, adaptable, and effective model-checking approach
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
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