In this paper, we reconsider a retrial queue with a number of servers and impatient customers. We improve the computation of the rate matrix, the conditional mean number of customers, the unknowns and the estimation of threshold N , which leads to th

1.1 General DMC series is the name given to the dot matrix character LCD display modules that have been developed by OPTREX CORPORATION. The modules consist of high contrast and large viewing angle TN and STN type LC (liquid crystal) panels. Each mod