The working face is the most dangerous place of coal mines, and it difficult (even impossible) to replenish energy by replacing batteries sensor nodes in faces. This paper presents a wireless charging method for this scenario that composed two sub methods called mining maintaining charging, respectively. Mining provides opportunistic services during process cutting through airborne Mobile Charg...

this paper analyzes a controllable discrete-time machine repair problem withl operating machines and two repairmen. the number of working servers can be adjusteddepending on the number of failed machines in the system one at a time at machine's failure orat service completion epochs. analytical closed-form solutions of the stationary probabilities ofthe number of failed machines in the sys...

This paper deals with bi-level control policy and queuing analysis of a machine repair problem. The model is developed by incorporating mixed standbys (cold and warm), reneging, set up and vacation time. The repair facility consists of two heterogeneous repairmen in the system. The life and repair time of the failed units and also their set up times are assumed to be exponentially distributed. ...