In this paper we define and study the class of stopwatch automata which are timed automata augmented with stopwatches and unobservable behaviour. In particular, we investigate the expressive power of this class of automata, and show as a main result that any finite or infinite timed language accepted by a linear hybrid automaton is also acceptable by a stopwatch automaton. The consequences of t...

Hybrid automata are well-studied formal models for dynamical systems. However, the analysis of hybrid automata is extremely difficult, and even state-of-the-art tools can only analyze systems with few continuous variables and simple dynamics. Because the reachability problem for general hybrid automata is undecidable, we give a path-oriented reachability analysis procedure for a class of nonlin...

This article describes the use of Stochastic Automata Networks (SAN) as a modelling tool. A SAN model consists of some individual stochastic automata that act more or less independently of each other. An automata is represented by a number of states and probabilistic rules that govern the manner in which it moves from one state to the next. The state of a SAN is given by the state of each of it...

Hybrid automata are often cited as the best model to describe and analyze controlcommand systems. However, no formal link exists between this high-level description and the low-level implementation of the control law (in C for example). In this article, we propose a framework that computes from a synchronous program an equivalent hybrid automata. To do this, we use an intermediate model, namely...

background: routinely collected data from tuberculosis surveillance system can be used to investigate and monitor the irregularities and abrupt changes of the disease incidence. we aimed at using a hidden markov model in order to detect the abnormal states of pulmonary tuberculosis in iran. methods: data for this study were the weekly number of newly diagnosed cases with sputum smear-positive p...

This article describes the use of Stochastic Automata Networks (SAN) as a modelling tool. A SAN model consists of some individual stochastic automata that act more or less independently of each other. An automata is represented by a number of states and probabilistic rules that govern the manner in which it moves from one state to the next. The state of a SAN is given by the state of each of it...

Hybrid systems are characterized by a mix of analog and digital inputs and outputs. We deene such systems formally as hybrid automata, and discuss how to specify interesting properties of them. A few approaches to verifying hybrid systems are outlined: reachability analysis, model-checking on nite-state approximating automata, theorem proving, and linear programming. These approaches work with ...

This paper presents availability computation procedure of a semi-Markovian mechatronic system under the uncertainties that involve randomness as well as fuzziness. Conversion of semi-Markov to Markov model is stated first and hybrid approach is then used for fuzzy availability computation. Sometimes statistical data is available about failure and repair rates, but in cases where such data is sc...

Background: Multiple Sclerosis (MS) is the most frequent non-traumatic neurological disease capable of causing disability in young adults. Detection of MS lesions with magnetic resonance imaging (MRI) is the most common technique. However, manual interpretation of vast amounts of data is often tedious and error-prone. Furthermore, changes in lesions are often subtle and extremely unrepresentati...