The traffic-adaptive medium access protocol (TRAMA) is introduced for energy-efficient collision-free channel access in wireless sensor networks. TRAMA reduces energy consumption by ensuring that unicast and broadcast transmissions have no collisions, and by allowing nodes to assume a low-power, idle state whenever they are not transmitting or receiving. TRAMA assumes that time is slotted and u...

The makespan minimization problem in flow shops with no-idle constraints on machines is considered. The latter means that each machine, once started, must process all its operations without intermediate idle time until all those operations are completed. The problem is known to be strongly NP-hard already for three machines. While being based on a geometrical approach, we propose several polyno...

Inserted idle time occurs when a machine is kept waiting deliberately for the arrival of a job that is still being processed on a preceding machine. A common assumption in most of the existing literature on flowshop scheduling is that inserted idle time is not allowed, and whenever there are jobs that are ready for processing on a given machine, that machine is not kept idle for any reason. Thi...

• Decision epochs are the beginning of every period. • Action space includes Keep (K), Release & Work (RW), Release & Idle (RI) and Idle (I) for each server. The 16 unique combinations of the two workers’ actions constitute the system’s action space. Action “Keep” requires the worker to continue working on the current job for one more period. Action “Release & Work” requires that the worker sto...

spend much of their time idle, and various schemes have been proposed to use this idle time productively. We have used this approach to improve overall performance in storage systems. The most common approach is to off-load activity from busy periods to less-busy ones in order to improve system responsiveness. In addition, speculative work can be performed in idle periods in the hope that it wi...

We study the problem of optimally controlling the use of sleep states in an energy-aware M/G/1 queue. In our model, we consider a family of policies where the server upon becoming idle can wait for a random period before entering, potentially randomly, any of a finite number of possible sleep states to save energy. The server becomes busy again after a possibly random number of jobs have arrive...

An open queueing network model in light traffic has been developed. The theorem on the law of the iterated logarithm for the idle time process of customers in an open queueing network has been presented. Finally, we present an application of the theorem a idle time model from computer network practice. Key–Words: mathematical models of technical systems, reliability theory, queueing theory, ope...