This paper studies the single server repairable queueing system with variable service rate and failure rate. The rule of variation is that changes when number customers in reaches a certain value. may fail at any time, rates idle periods busy are different. has one reliable repairman to repair server. steady-state joint distribution states obtained by matrix geometric solution method, availabil...

This article discusses recent experiences with the Numeral Unit Spread Assessment Pedigree (NUSAP) system for multidimensional uncertainty assessment, based on four case studies that vary in complexity. We show that the NUSAP method is applicable not only to relatively simple calculation schemes but also to complex models in a meaningful way and that NUSAP is useful to assess not only parameter...

We consider the MAP/M/c queue with markovian flow of breakdowns. There are K waiting positions for arrival customers in the system. The system we consider comprises c servers, of which one are has to work for the customers. The other servers is in the cold standby , repairing or waiting for repairing, only the working server can fails, and there is only one repairman. This model is quite genera...

In this study, stochastic modelling and analysis of a repairable 2-out-of-4 system is presented. The system under study is exposed to four types of failures and is attended by four repairmen. The failure and repair time are assumed exponentially distributed. Explicit expressions for mean time to system failure (MTSF), the steady-state availability, and busy period of repairman and profit functi...

We consider the estimation of arrival and service rates for queues based on queue length data collected at successive, not necessarily equally spaced, time points. In particular, we consider the M/M/c queue, for c large, but application of the method to the repairman problem is almost identical, and the general approach presented should extend to other queue types. The estimation procedure make...

Fractal patterns offer one way to represent the rough complexity of the natural world. Whilst they dominate many of our visual experiences in nature, little large-scale perceptual research has been done to explore how we respond aesthetically to these patterns. Previous research (Taylor et al., 2011) suggests that the fractal patterns with mid-range fractal dimensions (FDs) have universal aesth...