RFID Based Non-Preemptive Random Sleep Scheduling in WSN

In Wireless Sensor Network(WSN),because battery and energy supply are constraints,sleep scheduling is always needed to save energy while maintaining connectivity for packet delivery.Traditional schemes have to ensure high duty cycling to ensure enough percentage of active nodes and then derogate the energy efficiency.This paper proposes an RFID based non-preemptive random sleep scheduling scheme with stable low duty cycle.It employs delay tolerant network routing protocol to tackle the frequent disconnections.A low-power RFID based non-preemptive wakeup signal is used to confirm the availability of next-hop before sending packet.It eliminates energy consumption of repeated retransmission of the delayed packets.Moreover,the received wakeup signal is postponed to take effect until the sleep period is finished,and the waken node then responds to the sending node to start the packet delivery.The scheme can keep stable duty cycle and then ensure energy saving effect compared with other sleeping scheduling methods.

The impact of short-term changes in sleeping and eating patterns on glucometabolic health and gut microbiota in healthy young adults: a proof-of-concept controlled feeding study

Epidemiological studies showed that night workers are at higher risk of developing chronic metabolic diseases.However,no study has investigated the changes in circadian rhythms caused by a combined effect of sleep and diet in a real-life setting on cardiometabolic health,gut microbiota,and psychological status in healthy people.A 4-week step-wise misaligned-realigned controlled-feeding trial with a 2×2 factorial design(sleep and diet)was conducted on healthy young adults.At first,subjects experienced a one-week circadian rhythm misalignment with a high-fat fast-food diet,extended eating window,and delayed sleep schedules,then gradually transited to a complete circadian rhythm realignment with a high-fiber balanced diet,8-h timerestricted eating,and normal sleep schedules.Circadian rhythm misalignment led to significantly higher levels of fasting glucose and homeostatic model assessment for insulin resistance(HOMA-IR)of subjects compared to baseline and failed to recover to the baseline level in circadian rhythm realignments.Notably,the incremental area under the curve(iAUC)of postprandial glucose decreased with circadian rhythm adjustments as compared to that in circadian rhythm misalignment,suggesting circadian rhythm realignment by sleep or/and diet could partly restore glucose metabolism impaired by a short-term circadian rhythm misalignment.However,circadian rhythm changes did not result in overall perturbations of gut microbiota diversities.

Random and Periodic Sleep Schedules for Target Detection in Sensor Networks

We study random and periodic sleep schedules from the point of view of delay in detecting the target. We consider sleep schedules in which a sensor in ＂inactive＂ mode wakes up either randomly or periodically to detect presence of the target within its vicinity resulting into two sleep schedules： （a） random wake-up schedule, and （b） periodic wake-up schedule respectively. Specifically, we analyse and obtain for the random wake-up schedule the expected delay in detection, and the delay, such that with probability P, the delay is less than the computed value. For the periodic wake-up schedule we show that there exists an upper bound on the delay. Further we compute the average value of delay. We have shown that the theoretically computed averages and the upper bounds on the delay match with the simulation results for the random wake-up and periodic wake-up schedules.