1,064 research outputs found
Model-Checking an Ecosystem Model for Decision-Aid
International audience—This work stems on the idea that timed automata models and model-checking techniques may bring much in a decision-aid context when dealing with large and interacting qualitative models. In this paper, we focus on two key issues when facing the interpretation and explanation of behavior in real-world systems: the model building and its exploration using logic patterns. We illustrate this approach in the ecological domain with the modeling and exploration of a fisheries ecosystem
Model based fault diagnosis for hybrid systems : application on chemical processes
The complexity and the size of the industrial chemical processes induce the monitoring of a growing number of process variables. Their knowledge is generally based on the measurements of system variables and on the physico-chemical models of the process. Nevertheless, this information is imprecise because of process and measurement noise. So the research ways aim at developing new and more powerful techniques for the detection of process fault. In this work, we present a method for the fault detection based on the comparison between the real system and the reference model evolution generated by the extended Kalman filter. The reference model is simulated by the dynamic hybrid simulator, PrODHyS. It is a general object-oriented environment which provides common and reusable components designed for the development and the management of dynamic simulation of industrial systems. The use of this method is illustrated through a didactic example relating to the field of Chemical Process System Engineering
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Using formal methods to support testing
Formal methods and testing are two important approaches that assist in the development of high quality software. While traditionally these approaches have been seen as rivals, in recent
years a new consensus has developed in which they are seen as complementary. This article reviews the state of the art regarding ways in which the presence of a formal specification can be used to assist testing
Model and Integrate Medical Resource Available Times and Relationships in Verifiably Correct Executable Medical Best Practice Guideline Models (Extended Version)
Improving patient care safety is an ultimate objective for medical
cyber-physical systems. A recent study shows that the patients' death rate is
significantly reduced by computerizing medical best practice guidelines. Recent
data also show that some morbidity and mortality in emergency care are directly
caused by delayed or interrupted treatment due to lack of medical resources.
However, medical guidelines usually do not provide guidance on medical resource
demands and how to manage potential unexpected delays in resource availability.
If medical resources are temporarily unavailable, safety properties in existing
executable medical guideline models may fail which may cause increased risk to
patients under care. The paper presents a separately model and jointly verify
(SMJV) architecture to separately model medical resource available times and
relationships and jointly verify safety properties of existing medical best
practice guideline models with resource models being integrated in. The SMJV
architecture allows medical staff to effectively manage medical resource
demands and unexpected resource availability delays during emergency care. The
separated modeling approach also allows different domain professionals to make
independent model modifications, facilitates the management of frequent
resource availability changes, and enables resource statechart reuse in
multiple medical guideline models. A simplified stroke scenario is used as a
case study to investigate the effectiveness and validity of the SMJV
architecture. The case study indicates that the SMJV architecture is able to
identify unsafe properties caused by unexpected resource delays.Comment: full version, 12 page
Dynamic Data Structures for Timed Automata Acceptance
We study a variant of the classical membership problem in automata theory, which consists of deciding whether a given input word is accepted by a given automaton. We do so through the lenses of parameterized dynamic data structures: we assume that the automaton is fixed and its size is the parameter, while the input word is revealed as in a stream, one symbol at a time following the natural order on positions. The goal is to design a dynamic data structure that can be efficiently updated upon revealing the next symbol, while maintaining the answer to the query on whether the word consisting of symbols revealed so far is accepted by the automaton. We provide complexity bounds for this dynamic acceptance problem for timed automata that process symbols interleaved with time spans. The main contribution is a dynamic data structure that maintains acceptance of a fixed one-clock timed automaton ? with amortized update time 2^{?(|?|)} per input symbol
Symbolic Computation of Nonblocking Control Function for Timed Discrete Event Systems
In this paper, we symbolically compute a minimally restrictive nonblocking supervisor for timed discrete event systems, in the supervisory control theory context. The method is based on Timed Extended Finite Automata, which is an augmentation of extended finite automata (EFAs) by incorporating discrete time into the model. EFAs are ordinary automaton extended with discrete variables, guard expressions and action functions. To tackle large problems all computations are based on binary decision diagrams (BDDs). The main feature of this approach is that the BDD-based fixed-point computations is not based on “tick” models that have been commonly used in this area, leading to better performance in many cases. As a case study, we effectively computed the minimally restrictive nonblocking supervisor for a well-known production cell
Dynamic analysis overview and a proposed verification tool for temporal properties in security-critical software
The need for correct software is increasing as computers are proliferating in every aspect of our lives. Dynamic analysis is a possible way of
increasing the reliability of software by introducing a monitoring and verification mechanism over and above a computer system, so that if under
some unprecedented circumstance, any of its specifications are violated,
an alarm will be raised. This paper gives an overview of the literature
in the subject and also puts forward a proposal of further research and
investigation which seems to be very promising.peer-reviewe
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