In IEEE 802.16e, with the popularization of multimedia services, multicast and unicast services are coexisted in one mobile subscriber station (MSS). The mobile devices are generally powered by energy-limited battery. Thus, the power saving is the important issue of extending the lifetime of MSSs. In this paper we have proposed a Multicast Services Based Scheduling (MSBS) algorithm that improves energy efficiency for both unicast and multicast services, and conforms QoS requirements of MSSs in IEEE 802.16e wireless networks. MSBS schedules packets based on a deadline for each packet determined from QoS parameters and reduces energy consumption of MSSs by minimizing the switching energy. Simulation results show that, MSBS can reduce significant overall energy and prolong lifetime of the MSSs.

In IEEE 802.16e networks, with the popularisation of multimedia services, multicast and unicast services can coexist in one mobile subscriber station (MSS). The mobile devices are generally powered by battery, which is limited in energy. Thus, power saving is an important issue to be considered for extending the lifetime of the MSSs. The authors have proposed a multicast services-based scheduling (MSBS) algorithm that improves the energy efficiency of both unicast and multicast services, while satisfying the quality of service requirements of the MSSs in 802.16e wireless networks. MSBS schedules the packets in such a way that each packet is transmitted before its deadline and the energy consumed by the MSSs is reduced by minimising the number of state transitions by the MSSs. The simulation results show that MSBS can produce significant overall energy-saving and prolonged lifetime as compared to other scheduling schemes in 802.16e wireless networks.

Field inspection is a traditional way to detect the problem of shaft imbalance or abnormal vibration in a ship propulsion system; however, the ship cannot execute any tasks or activities during calibration. This study develops a human-machine monitoring interface (HMMI) to estimate vibration abnormalities and implement an intelligent active balance correction to the propulsion system online. In this study, Arduino IDE, InduSoft, and LabVIEW are used to create a function monitored by HMMI. By comparing the abnormal vibration amplification of the moment of inertia, HMMI calculates the correct mass to reduce the vibration. The experimental results show that, after HMMI carries out continuous active balance correction online, the correction rate achieves 105.37%. This indicates that HMMI can calculate the amount of imbalance and phase angles and drive a counterweight to the correct balance position while the device is still operating.