Probabilistic safety assessment (PSA) which plays a crucial role in risk evaluation is a quantitative approach intended to demonstrate how a nuclear reactor meets the safety margins as part of the licensing process. Despite PSA merits, some shortcomings associated with the final results exist. Conventional PSA uses crisp values to represent the failure probabilities of basic events. This causes...

Fault Tree Analysis (FTA) as a Probabilistic Risk Assessment (PRA) method is used to identify basic causes leading to an undesired event, to represent logical relation of these basic causes in leading to the event, and finally to calculate the probability of occurrence of this event. To conduct a quantitative FTA, one needs a fault tree along with failure data of the Basic Events (BEs). Someti...

Modelling and analysing risk is one of the most critical activity in system engineering. However, in literature approaches like Fault Tree Analysis, Event Tree Analysis, Failure Modes and Criticality Analysis focus on the system-to-be without considering the impact of the associated risks to the organization where the system will operate. The Tropos framework has been proved effective in modell...

We relate the epistemic irrelevance in Walley’s behavioural theory of imprecise probabilities to the event-tree independence due to Shafer. In particular, we show that forward irrelevance is equivalent to event-tree independence in particular event trees, suitably generalised to allow for the fact that imprecise rather than precise probability models are attached to the nodes in the tree. This ...

We report on the development of a social media monitoring tool based on the novel Social Media Event Sentiment Timeline (SoMEST) model. The novelty of our model is that it combines opinion mining techniques with a timeline-based event analysis method and an information and event extraction tool. While Event Timeline Analysis (ETA) is an existing method utilized in analyzing the external environ...