the traditional event tree analysis uses a single probability to represent each top event. however, it is unrealistic to evaluate the occurrence of each event by using a crisp value without considering the inherent uncertainty and imprecision a state has. the fuzzy set theory is universally applied to deal with this kind of phenomena. the main purpose of this study is to construct an easy metho...

The traditional event tree analysis uses a single probability to represent each top event. However, it is unrealistic to evaluate the occurrence of each event by using a crisp value without considering the inherent uncertainty and imprecision a state has. The fuzzy set theory is universally applied to deal with this kind of phenomena. The main purpose of this study is to construct an easy metho...

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...

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...

Antigen sequence typing (ST) of FetA is part of the molecular typing scheme of Neisseria meningitidis. Among invasive meningococcal isolates from 2,201 patients in Germany, we identified 11 strains lacking the fetA gene because of deletions mediated by repeat arrays flanking the gene, i.e., Correia elements, repeat sequence 13 (RS13), and duplicated RS3. Geographic mapping and multilocus ST of ...

Abstract: Event tree is a logical analysis of probability for outcome events by initiating event and probable subsequent events. However, the evaluation of every single event may contain vague information or cannot be described by a crisp number of probabilities in application. So this paper aims to develop an event tree by using fuzzy set theory with a combination of triangle membership functi...

Chemical Process Plant as a complex system requires good scientific knowledge on different issues including Process Safety Analysis (PSA). Fuzzy logic is the collective name for “Fuzzy set analysis” and “Possibility theory”, able to use random or approximate data in the Process Safety Analysis. This paper explains the impact of fuzzy set theory for basic tools used in Process Safety Analysis. I...