Backpressure meets taxes: Faithful data collection in stochastic mobile phone sensing systems

The use of sensor-enabled smart phones is considered to be a promising solution to large-scale urban data collection. In current approaches to mobile phone sensing systems (MPSS), phones directly transmit their sensor readings through cellular radios to the server. However, this simple solution suffers from not only significant costs in terms of energy and mobile data usage, but also produces heavy traffic loads on bandwidth-limited cellular networks. To address this issue, this paper investigates cost-effective data collection solutions for MPSS using hybrid cellular and opportunistic short-range communications. We first develop an adaptive and distribute algorithm OptMPSS to maximize phone user financial rewards accounting for their costs across the MPSS. To incentivize phone users to participate, while not subverting the behavior of OptMPSS, we then propose BMT, the first algorithm that merges stochastic Lyapunov optimization with mechanism design theory. We show that our proven incentive compatible approaches achieve an asymptotically optimal gross profit for all phone users. Experiments with Android phones and trace-driven simulations verify our theoretical analysis and demonstrate that our approach manages to improve the system performance significantly (around 100%) while confirming that our system achieves incentive compatibility, individual rationality, and server profitability

Impact of Intracranial Pressure-Monitored Therapy on Mortality in Patients with Severe Traumatic Brain Injury

Objective:  To assess the impact of intracranial pressure (ICP) monitored therapy on mortality in patients with severe traumatic brain injury. Materials and Methods:  A randomized controlled trial was conducted at the Department of Neurosurgery, Jinnah Hospital Lahore. Forty patients of both genders, aged between 15 to 60 years were randomly selected and divided into two groups (Control & Experimental). Patients injured within 24 hours with a Glasgow Coma Scale (GCS) of 8 or less and showing radiological evidence of raised intracranial pressure were included. Patients with extradural hematoma, penetrating injury, or those requiring any surgery were excluded from the study. Data were analyzed using SPSS version 20. Results:  No significant difference was found in mean age and gender among the two groups. The GCS of the control group was 6.2 ± 1.6 while that of the experimental group was 6.7 ± 1.6. The mean of the maximum ICP of the experimental group was 25.31 ± 8.48 mm of Hg. There was a significant difference in the mean duration of ventilation between the two groups. In the control group, 10 (50.0%) patients expired whereas in the experimental group, 8 (40.0%) patients expired. The proportion of mortality was higher in the control group but the difference was not statistically significant between the two groups (P value: 0.525). Conclusion:  Intracranial pressure-monitored therapy was effective but statistically showed no significant superiority over unmonitored management.&nbsp