This paper shows how heterogeneous stochastic modelling techniques of increasing modelling power can be applied to assess the safety of a digital control system. First, a Fault-Tree (FT) has been built to model the system, assuming two-state components and independent failures. Then, the FT is automatically converted into a Bayesian Network, allowing to include more modelling details and locali...

A single interface for accessing life sciences (LS) data is a natural need to master the data deluge in this domain. The data in the LS requires integration and current integrative solutions increasingly rely on the federation of queries for distributed resources. This paper demonstrates BioFed, a federated SPARQL query processing system customised for LS-LOD. BioFed enables user to formulate a...

In temporal-logic model checking, we verify the correctness of a program with respect to a desired behavior by checking whether a structure that models the program satis es a temporal-logic formula that speci es the behavior. The main practical limitation of model checking is caused by the size of the state space of the program, which grows exponentially with the number of concurrent components...

The current technology of veriication engineering requires personnels to be well-trained in logics and au-tomata theory, such that in order to attack the well-known state-space explosion problem they must carefully tune existing veriication packages. Several researches have resulted in a large number of techniques for reducing the system state-space, such as symmetry-based reductions , partial-...

The simulation of discrete stochastic models using state space-based methods has recently become practical through the proxel-based simulation algorithm. Proxels implement the method of supplementary variables and generate a DTMC of the model’s state space. However, due to state space explosion the method does not yet work efficiently on larger models. By using discrete phase-type approximation...

In temporal-logic model checking, we verify the correctness of a program with respect to a desired behavior by checking whether a structure that models the program satisses a temporal-logic formula that speciies the behavior. The main practical limitation of model checking is caused by the size of the state space of the program, which grows exponentially with the number of concurrent components...

Achieving the appropriate performance requirements for computer– communication systems is as important as the correctness of the endresult. This is particularly difficult in the case of massively parallel computer systems such as the clusters of PCs behind the likes of Google and peer-to-peer filesharing networks such as Bittorrent. Measuring the performance of such systems using a mathematical...

In this report, we consider two promising methods for alleviating the state space explosion problem in reachability analysis: the symmetry method and the stubborn set method. We concentrate on the computation of symmetries and stubborn sets. The new algorithms presented in this report help us to save time and space in the symmetry method and to avoid inspecting redundant states in the so called...

We investigate the problem of temporal planning with concurrent actions having stochastic durations, especially in the context of extended-state-space based planners. The problem is challenging because stochastic durations lead to an explosion in the space of possible decision-epochs, which exacerbates the familiar challenge of growth in executable action combinations caused by concurrency. We ...

We investigate the existence and uniqueness of strong solutions up to an explosion time for regime-switching diffusion processes in an infinite state space. Instead of concrete conditions on coefficients, our existence and uniqueness result is established under the general assumption that the diffusion in every fixed environment has a unique non-explosive strong solution. Moreover, non-explosio...