This paper provides a framework for integrating fuzzy expert systems with discrete event simulation, which will be utilized to enhance the input modeling process in discrete event simulation. Predicting the activity output (i.e. duration) using fuzzy expert systems will provide a new modeling feature to discrete event simulation. In previous studies, fuzzy set theory was mainly utilized to cont...

With the rapid development of Internet of Things (IoT), enormous events are produced by various kinds of devices at high speed. Complex Event Processing (CEP) is the key part of IoT middleware which can help the user to get semantic meanings of primitive events. Context-awareness is an important feature of CEP engine. In this paper a high performance distributed context-aware CEP architecture a...

The event detection is one of the fundamental researches in wireless sensor networks (WSNs). Due to the consideration of various properties that reflect events status, the Composite event is more consistent with the objective world. Thus, the research of the Composite event becomes more realistic. In this paper, we analyze the characteristics of the Composite event; then we propose a criterion ...

In economic order quantity models without backordering, both the stock cost of each unit quantity and the order cost of each cycle are characterized as independent fuzzy variables rather than fuzzy numbers as in previous studies. Based on an expected value criterion or a credibility criterion, a fuzzy expected value model and a fuzzy dependent chance programming (DCP) model are constructed. The...

In this paper fuzzy set theory has been applied to discrete event simulation to model uncertainty in input data. Various approaches to fuzzy simulation have been proposed in literature, even if many problems are still to be solved. The key points are how to manage the simulation event list and how to update the fuzzy simulation clock. These two tasks are mainly based on the ranking algorithm. I...

In this paper we propose an alternative use of commercial object-oriented discrete-event simulators. We attempt to bridge the intrinsic inaccuracy of simulators in modelling real systems affected by fuzziness. The strategy adopted, called pseudo-fuzzy discrete event simulation, models fuzziness through a set of several classic simulation runs to trace an output fuzzy performance function. The i...

This study investigates whether people represent the beginnings and ends of events as fuzzy temporal frames and subsequently construct event temporal relations. The study adopted Allen’s (1984; 1991) seven logical categories of temporal relations. Constructing the seven relations often requires the accurate encoding and (or) retrieval of the beginnings and ends of events. We used a recurrent ne...

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...