In this paper, we consider GI/M/c queues with two classes of vacation mechanisms: Station vacation and server vacation. In the first one, all the servers take vacation simultaneously whenever the system becomes empty, and they also return to the system at the same time, i.e., station vacation is group vacation for all servers. This phenomenon occurs in practice, for example, when the system con...

We consider a problem of repeatedly scheduling n jobs on m parallel machines. Each job is associated with a profit that is gained each time the job is completed, and the goal is to maximize the average profit per time unit. Once the processing of a job is completed, it goes on vacation and returns to the system, ready to be processed again, only after its vacation is over. This problem has many...

we consider an m/g/1 queue with regular and optional phase vacation and withstate dependent arrival rate. the vacation policy is after completion of service if there are no customers in the system, the server takes vacation consisting of k -phases, each phase is generally distributed. here the first phase is compulsory where as the other phases are optional. for this model the supplementary var...

System reliability indices deal with the adequacy of overall system supply and indicates behaviour response. The index express interruption statistics in terms customers which can be an individual, firm, or organization that purchases electric services at one location under rate classification, contract schedule. include: Average Interruption Frequency Index (SAIFI), Duration (SAIDI), Customer ...

Treatment of advanced cancers has benefited from new agents that supplement or bypass conventional therapies. However, even effective therapies fail as cancer cells deploy a wide range of resistance strategies. We propose that evolutionary dynamics ultimately determine survival and proliferation of resistant cells. Therefore, evolutionary strategies should be used with conventional therapies to...

Preparing a schedule for physicians in the emergency room is a complex task, which requires taking into account a large number of (often conflicting) rules, related to various aspects: limits on the number of consecutive shifts or weekly hours, special rules for night shifts and weekends, seniority rules, vacation periods, individual preferences,... In this paper, we present a mathematical prog...

We evaluated 2 3-component multiple-schedule sequences-a response interruption and redirection (RIRD) treatment sequence and a no-interaction control sequence-using a multielement design. With this design, we were able to evaluate the immediate and subsequent effects of RIRD on 2 participants' vocal stereotypy. For both participants, RIRD produced an immediate decrease in vocal stereotypy and d...